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Pre-Proposal

PRE-PROPOSAL FOR

Chittagong 2x660MW Coal-Fired

Power Plant Project

October 31, 2014

ORIGINAL


Pre-Proposal

Pre-Proposal

PROJECT NAME : Chittagong(2x660MW) CFPP Project

Country : Bangladesh

OWNER : POSCO & BMTF Consortium

REV.

NO. DATE DESCRIPTION PREP'N CHECK REVIEW APPROVAL

REV.

NO. PREPARATIONCOMPANY PREPARATION CHECK REVIEW APPROVAL

This Document is the property of PE&C. Therefore, it shall not be released to

any third party without permission of an authorized personnel of the PE&C.

For Pre-Proposal


Pre-Proposal

TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................................................................ 6

1.1 BACKGROUND ....................................................................................................................................................................... 6

1.2 ECONOMIC OVERVIEW OF BANGLADESH ......................................................................................................................... 6

1.3 POWER SECTOR OF BANGLADESH ......................................................................................................................... 7

1.4 CHRONIC POWER PROBLEMS OF BANGLADESH ............................................................................................................. 8

2. CURRENT STATUS AND ISSUES OF IMPORTED COAL .................................................................... 10

2.1 THE ADVANTAGE OF COAL ............................................................................................................................................... 10

2.2 GLOBAL COAL DEMAND & SUPPLY ............................................................................................................................... 10

2.3 PRICE TRENDS ..................................................................................................................................................................... 12

2.4 THE FORECAST OF GLOBAL COAL PRICE ....................................................................................................................... 14

3. PROJECT OVERVIEW .............................................................................................................................. 15

3.1 PROJECT OVERVIEW ........................................................................................................................................................... 15

4. COST ESTIMATION ................................................................................................................................. 17

4.1 COST OF THE PROJECT ...................................................................................................................................................... 17

4.2 OPERATING AND MAINTENANCE EXPENSES.................................................................................................................. 17

4.3 FUEL COST ........................................................................................................................................................................... 19

4.4 TAXATION ............................................................................................................................................................................ 20

5. REVENUE ESTIMATION .......................................................................................................................... 21

5.1 REVENUE ANALYSIS ........................................................................................................................................................... 21

6. FINANCIAL ANALYSIS ............................................................................................................................ 24

6.1 THE BASIC CONDITIONS ................................................................................................................................................... 24

6.2 INFLATION RATE ................................................................................................................................................................. 24

6.3 FUNDING ............................................................................................................................................................................. 25

6.4 LOAN SCHEDULE AND INTEREST EXPENSES ................................................................................................................... 26

6.5 IRR, ROE ............................................................................................................................................................................ 26

7. SENSITIVITY ............................................................................................................................................. 28

7.1 RESULTS OF SENSITIVITY ................................................................................................................................................... 28

8. OUTLINE OF PLANT CONFIGURATION ............................................................................................... 17

9. SITE INFORMATION AND ENVIRONMENTAL REQUIREMENTS ..................................................... 30


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9.1 PROPOSED SITE LOCATION ............................................................................................................................................... 30

9.2 REQUIRED AREA OF THE TOTAL POWER PLANT ........................................................................................................... 30

9.3 SITE LAYOUT ....................................................................................................................................................................... 30

9.4 ENVIRONMENTAL REQUIREMENTS ................................................................................................................................... 31

10. SCOPE OF SUPPLY .................................................................................................................................. 35

10.1 SCOPE OF WORKS AND SERVICES AS EPC CONTRACTOR’S RESPONSIBILITY .......................................................... 35

10.2 SCOPE OF WORKS AND SERVICES AS IPP DEVELOPER’S RESPONSIBILITY .................................................................. 42

10.3 OUT OF SCOPE OF WORKS TO BE PROVIDED BY OTHERS ........................................................................................... 42

11. DESIGN DESCRIPTION ........................................................................................................................... 43

11.1 TENTATIVE DESIGN CRITERIA ........................................................................................................................................... 43

11.2 EXPECTED PLANT PERFORMANCE .................................................................................................................................... 48

11.3 CODES AND STANDARDS .................................................................................................................................................. 48

11.4 SUBMISSION REQUIREMENTS ........................................................................................................................................... 51

11.5 BOILER AND FLUE GAS TREATMENT FACILITIES ............................................................................................................ 52

11.6 STEAM TURBINE AND AUXILIARIES .................................................................................................................................. 55

11.7 FEED WATER SYSTEM ......................................................................................................................................................... 58

11.8 COAL AND ASH HANDLING SYSTEM .............................................................................................................................. 60

11.9 COOLING WATER SYSTEM ................................................................................................................................................. 62

11.10 STACKS ............................................................................................................................................................................ 63

11.11 CIVIL WORKS ................................................................................................................................................................. 63

11.12 BUILDING LIST ................................................................................................................................................................ 75

11.13 ELECTRICAL EQUIPMENT ............................................................................................................................................... 76

11.14 INSTRUMENT AND CONTROL ...................................................................................................................................... 80

11.15 WATER AND WASTEWATER TREATMENT SYSTEM ................................................................................................... 84

11.16 FIREFIGHTING SYSTEM................................................................................................................................................... 88

11.17 HVAC SYSTEM .............................................................................................................................................................. 91

12. OPERATIONAL REQUIREMENTS ........................................................................................................... 93

12.1 GENERAL .............................................................................................................................................................................. 93

12.2 PLANT DUTY ....................................................................................................................................................................... 93

13. APPENDIX ................................................................................................................................................ 94

13.1 DIAGRAM OF TERMINAL POINTS ..................................................................................................................................... 94

13.2 HEAT BALANCE DIAGRAM ................................................................................................................................................ 94

13.3 WATER BALANCE DIAGRAM .............................................................................................................................................. 94


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13.4 PLOT PLAN .......................................................................................................................................................................... 94

13.5 SINGLE LINE DIAGRAM ....................................................................................................................................................... 94

13.6 CONTROL SYSTEM CONFIGURATION ............................................................................................................................... 94


Pre-Proposal

1. Introduction

1.1 Background

Bangladesh mainly uses gas-fired power generation utilizing domestic natural gas as its

major sources, and the future development plan for new power generation still focuses

on domestic natural gas as a main energy resource.

However, since the current domestic demand has increased rapidly and the production

or currently available domestic natural gas will face depletion in the near future, it is not

realistic to establish a policy that depends too heavily on domestic natural gas for the

development of a new long-term power generation plan.

Bangladesh has a limited generation capacity of approximately 5.5GW with a daily

availability of 4GW. The capacity is below the ever growing demand of the country,

which leads to frequent load shedding. More over Bangladesh electrification is only 47%,

with most of the supply limited to city needs. Also, it is expected that the on-going

liberalization of the country’s economic policy would accelerate the industrial growth,

which would further increase the demand for power. Although several new power

projects have been identified with a view to bridge the gap between demand and

availability, only a few could be taken up for implementation, due to financial and other

constraints. Lack of availability of sufficient electric power has always been one of the

greatest deterrents to the growth of industry in Bangladesh.

Bangladesh uses indigenous natural gas to generate about 87% of its power. Other

generations are hydro, coal and liquid fuel based. Renewable energy has just started

making a small contribution.

To mitigate such a gap between domestic power demand and supply in Bangladesh

and diversify the power source relied on natural gas, POSCO & BMTF consortium

propose to build the large-sized imported coal-fired high efficiency power plant with this

proposal hereto.

1.2 Economic Overview of Bangladesh

In real terms Bangladesh's economy has grown 5.8% per year since 1996 despite

political instability, poor infrastructure, corruption, insufficient power supplies, and slow

implementation of economic reforms. Bangladesh remains a poor, overpopulated, and

inefficiently-governed nation. Although more than half of GDP is generated through the

service sector, 45% of Bangladeshis are employed in the agriculture sector with rice as

the single-most-important product. Bangladesh's growth was resilient during the 2008-


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09 global financial crisis and recession. Garment exports, totaling $12.3 billion in FY09

and remittances from overseas Bangladeshis, totaling $11 billion in FY10, accounted for

almost 12% of GDP.

<Basic Economic Facts (FY 2012)> Item Content

GDP (purchasing power parity) $305.5 billion (2012 est.)

GDP (official exchange rate) $118.7 billion

GDP - real growth rate 6.1%

GDP - per capita (PPP) $2,000

GDP - composition by sector agriculture: 17.3%, industry: 28.6%, services: 54.1%

Unemployment rate 5%

Exchange rates taka (BDT) per US dollar - 82.17

Public debt 31.7% of GDP (2012 est.)

Stock of direct foreign investment

- at home: $6.64 billion (31 December 2012 est.)

Stock of direct foreign investment

- abroad: $108 million (31 December 2012 est.)

(Source: Central Intelligence Agency)

1.3 POWER SECTOR OF BANGLADESH

Bangladesh has shown tremendous growth in recent years. A booming economic

growth, rapid urbanization and increased industrialization and development have

increased the country's demand for electricity. Presently, 60% of the total population

(including renewable energy) has access to electricity and per capita generation is 292

kWh, which is very low compared to other developing countries. Noncommercial energy

sources, such as wood fuel, animal waste, and crop residues, are estimated to account

for over half of the country's energy consumption. Bangladesh has small reserves of oil

and coal, but very large natural gas resources. Commercial energy consumption is

mostly natural gas around 66%, followed by oil, hydropower and coal.

Electricity is the major source of energy for country's most of the economic activities.

Bangladesh's installed electric generation capacity was 6361 MW in 2011; only three-

fourth of which is considered to be ‘available’. Only 49% of the population has access to

electricity with a per capita availability of 136 kWh per annum. Overall, the country's

generation plants have been unable to meet system demand over the past decade. As

of 2011, 79 natural gas wells are present in the 23 operational gas fields which produce

over 2000 millions of cubic feet of gas per day (MMCFD). It is well short of over 2500

MMCFD that is demanded, a number which is growing by around 7% each year. In fact,


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more than three-quarters of the nation’s commercial energy demand is being met by

natural gas. This influential sector caters for around 40% of the power plant feedstock,

17% of industries, 15% captive power, 11% for domestic and household usage, another

11% for fertilizers, 5% in Compressed Natural Gas (CNG) activities and 1% for

commercial and agricultural uses.

<Bangladesh Power sector at a Glance (FY 2012)>

Item Content

Generation Capacity 8525 MW

Present Demand 7500 MW

Present Generation 5600-6350 MW

Highest Generation 6350 MW ( August 04, 2012)

Per Capita Generation 292 kWh

Transmission line 8949 KM

Distribution Line 2,81,123 KM

Total consumers 13.99 Million

Access to Electricity 60%

Electricity Growth 12 % (Since 2011)

(Source: Power Division, Ministry of Power, Energy & Mineral Resources)

1.4 Chronic Power Problems of Bangladesh

Problems in the Bangladesh's electric power sector include corruption in administration,

high system losses, and delays in completion of new plants, low plant efficiencies,

erratic power supply, electricity theft, blackouts, and shortages of funds for power plant

maintenance. A USAID report on energy conditions of Bangladesh states that Energy in

Bangladesh is indispensable for almost all economic activities, ranging from farm

irrigation to the manufacture of goods by small and micro enterprises. Importantly,

energy is also indispensable for attaining the Millennium Development Goals (MDGs)

for Bangladesh. Although endowed with natural gas resources and some good quality

coal deposits, Bangladesh continues to reel from widespread power shortages due to a

lack of investment in power generation and the inadequate distribution of infrastructure.

While there has been some improvement in generation capacity in the recent past. The

country can currently generate about 4500 megawatts (MW), while peak demand can

be as high as 6000 MW. With only 49% of Bangladeshis having access to electricity,

the per capita energy use is only 180 Kilowatt-hours (kwh), which is one of the lowest in

the region.


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Nevertheless, the country desires to make electricity available to all by 2021. People in

rural areas suffer more than those in urban areas from low access to electricity. Even

those who have electricity experience frequent outages and poor quality power. In

generating and distributing electricity, the failure to adequately manage the load leads to

extensive load shedding which results in severe disruption in the industrial production

and other economic activities. A recent survey reveals that power outages result in a

loss of industrial output worth $1 billion a year which reduces the GDP growth by about

half a percentage point in Bangladesh. A major hurdle in efficiently delivering power is

caused by the inefficient distribution system. It is estimated that the total transmission

and distribution losses in Bangladesh amount to one-third of the total generation, the

value of which is equal to US $247 million per year.


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2. CURRENT STATUS AND ISSUES OF IMPORTED COAL

2.1 The advantage of Coal

The world’s coal reserves are extraordinarily large and widely dispersed, with proved

reserves of 860 billion tones. Coal is safe and easy to transport, and it can be readily

stored. Reflecting these attributes, as well as the reserves base of developing

economies including China and India, the use of coal continues to grow strongly

relative to other fossil fuels.

As per the report of World Coal Association, over the past 30 years, the amount of

electricity produced from coal globally has more than tripled. This is mainly due to the

relatively low cost of building and running coal-fired power plants. The overall cost of

generating electricity is one of the most important factors determining the choice of

technology for new power generation. This is not only true in developing countries

where universal access to energy services is still a challenge, but also in the

established economies where electricity prices are an important variable for the

standard of living of many households. According to studies by the European

Commission, MIT, and the US Congressional Budget Office, coal power plants provide

electricity at a lower cost than nuclear or gas plants. This is also confirmed by levelised

generation cost studies, such as the one carried out regularly by the International

Energy Agency (IEA), which takes account of all the costs over the power plant lifetime.

According to IEA statistics, coal-based electricity is, on average, 7% cheaper than gas

and around 19% cheaper than nuclear.

The advantage of coal is even greater in comparison to renewable energy. IEA and

European Commission studies show that onshore wind costs between US$50 and

US$156 per MWh and solar photovoltaics between US$226 to US$2031. In certain

locations hydro resources can produce electricity at a cost comparable to coal,

however estimates vary greatly according to geographic conditions and the final price

can be as high as US$240 and US$262 per MWh. In comparison, electricity from coal

costs between US$56 to US$82 per MWh.

2.2 Global Coal Demand & Supply

2.2.1 Global Coal Demand

Since 2000, global coal consumption has grown faster than any other fuel.

According to the “World Energy Outlook 2011” by IEA, the 10-year average of

world coal consumption was 4.6% and it grew by 5.4% in 2011, while both China


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and India increased coal consumption by over 9%. Coal accounted for 30.3% of

world energy consumption in 2011 and its share is now over 70% in China and

nearly 53% in India. Coal consumption in China approached half (49.4%) of

global coal consumption in 2011, and India about 8%.

The following graph shows the result of world coal demand through 2010 and the

IEA’s prediction until 2035. Predicted scenario presented in the World Energy

Outlook shows three national approaches towards climate change, which are

Current Policies Scenario, New Policies Scenario, and the 450 Scenario. New

Policies Scenario is a scenario that takes account of broad policy commitments

and plans that have been announced by countries, including national pledges to

reduce greenhouse-gas emissions and plans to phase out fossil-energy subsidies.

450 Scenario is a scenario that sets out an energy pathway consistent with the

goal of limiting the global increase in temperature to 2°C by limiting concentration

of greenhouse gases in the atmosphere to around 450 parts per million of CO2.

In terms of future demand trends, the global coal demand is expected to increase

by 1.9% per annum growth rate from 4.7 billion tones in 2009 to 7.7 billion tones

in 2035 under the current policy scenario. Even under the new policy scenario7,

the demand is expected to remain unchanged since2020, but reach 5.9 billion

tones in 2035.

(Source: IEA World Energy Outlook 2011)

Coal demand has been increasing rapidly since 2002 and coal price has been

rising as a result. The period of stable demand was of stable coal prices also but

in situations where rapidly increasing coal demand in non-OECD countries in


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recent years, tight supply has caused coal prices to increase and uncompetitive

coal resources will allow the mining of coal and an increase in coal supply as the

result. Therefore, the future price of coal is expected to rise until stabilizing the

balance between supply and demand.

2.2.2 Global Coal Production

Countries with a higher export volume of coal are Indonesia, Australia, and then

Russia. In high-volume production countries such as China, the United States

and India, coal is essentially devoted to domestic consumption and exports are

minimal. China has recently become a net importer.

<Countries with a Higher Export Volume of Coal>

(Unit: Million ton per year)

Country Export (Million t per year)

Indonesia 383

Australia 301

Russia 134

USA 114

Colombia 828

South Africa 74

Canada 35

(Sources: BP, IEA, World Steel Association, WEC 2012)

2.3 Price Trends

Australian thermal coal price index, until around 2003, had remained at about $20 ~ $30

per ton, but began to rise from around 2004 with similar trends in other energy prices, and

reached around $180 per ton before the financial crisis in 2008. After that, the coal price

index fell to about $60 per ton due to weak demand, and then recovered due to the

expansion of China’s coal imports. Coal prices in 2010 due to a slowdown in production

caused by heavy rain in Australia in January have risen to $120 per ton.


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-40.00%

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Indonesian Coal Price Reference Australian Coal Price

The average Australian coal price of recent 10 years is about $86 per ton and the 5 years

average increased to about $103 per ton mostly due to the expansion of China’s coal

imports.

(Source: World Bank, 2013)

This price is considered to be one indicator in the contracts between other Asian

consumers such as South Korea, Taiwan and China and suppliers, because Indonesian

coal price trends have a similar trend with the Australian coal price. The reference price is

also considered to be an indicator in the negotiation of contracts of Indonesian coal exports.

The Indonesian coal price seems to have remained at a constant difference to the

Australian coal price due to a quality gap. But it should be noted that China and India has

increased the import of less middle or low-grade coal and so the Indonesian coal price

advantage may be affected by trends in such importers. The following graph indicates the

Indonesian coal price (HBA) that shows similar trends to Australian coal price. It is the price

that the government of Indonesia has been publishing a monthly since January 2009 to be

used by coal producers for all spot and term contracts. It is on a rising trend since

November 2012, but lost its way to reach US$ 100 per ton since April.

(Source: Ministry of Energy & Mineral Resources of Indonesia, 2013)


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2.4 The Forecast of Global Coal Price

Long-term coal price scenario of IEA in World Energy Outlook 2011 said that the

current policy scenario assumes $110 per ton of coal import price of the OECD.

Moreover, in the long-term coal price forecast financial institutions are assumed to be

approximately from $ 80 to $100 per ton units in general.

< Long-term Coal Price Scenario for OECD Countries>

(Unit: USD per ton)

Current Policies Scenario New Policies Scenario

2015 2020 2025 2030 2035 2015 2020 2025 2030 2035

104.6 109.0 112.8 115.9 118.4 103.7 106.3 108.1 109.3 110.0

(Source: IEA World Energy Outlook 2011, Real terms, 2010 prices)

However, the following graph indicates World Bank’s expectation of the Australian Coal

price, and it shows a little gap with IEA’s.

(Unit: per ton)

Coal 2013 2014 2015 2016 2017 2018 2019 2020 2025

Australian 90 91 90 91 91.9 92.9 93.9 94.9 100

(Source: World Bank Commodity Forecast Price data, July 2013)


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3. PROJECT OVERVIEW

3.1 Project Overview

3.1.1 Background of the project

This project is promoted as part of BPDA’s (Bangladesh Power Development

Board, 2011) a future power plant construction plans, Bangladesh Plan are as

follows:

No Description Capacity(MW) Probable Location(s)

1 Domestic Coal 11,250 North West Region at Mine Mouth

2 Imported Coal 8,400 Chittagong and Khulna

3 Domestic gas/LNG 8,850 Near Load Centers

4 Nuclear 4,000 Ruppur

5 Regional Grid 3,500 Bahrampur - Bheramara, Agartola -

Comilla, Silchar - Fenchuganj, Purnia-Bogra, Myanmar - Chittagong

6 Others 2,700 Near Load Centers

Total 35 38,700

(Source: BPDA(An Overview of Power Sector of Bangladesh, 2011)


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The prime objective of this project is to avail 1,320 MW electricity to the people of

Bangladesh within the shortest possible time probably 5 years or less and of

under the budget using world's best EPC. The average Bengali only uses 252

KWH per capita, while this ratio is 561 KWH in India and 12,900 KWH in USA.

We would like to improve the life of people in Bangladesh and get them double

the amount they have now through this project. The other objectives of this

project are to look at the best way to go for the workers and the country and to

make it number 1 employer in Bangladesh by giving employees the following:

All advancement to the employees

Plant completely running by only Bengals in 5 years

Giving all the employees a free hot lunch program

Free medical clinic for all the employees and their families

ISO Training for all employees (ISO9001 is an internationally recognized

Quality Management System)

High School and College courses given free to all employees

Better than average pay and retirement program

Plus much more

3.1.2 Site

This project will be built on the Bay of Bengal at Chittagong location, Bangladesh.

The port of Chittagong is the principle port of the People’s Republic of

Bangladesh. It is situated on the southern area at Matarbari island.

3.1.3 Project structure

The investment structure of the project is as follows:

POSCO is scheduled to participate as a major shareholder and also will perform

EPC work. In addition, foreign investors are reviewing investment.


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4. COST ESTIMATION

4.1 Cost of the Project

4.1.1 Estimated Total- Project-cost

The estimated total investment for project is as follows:

(Unit: Million USD)

Item Amount Remark

EPC EPC 1,740

Other EPC 233

Incidental Financing Fees 69

Total Project Cost 2,042

Interest during construction 306

Total Investment 2,349

In addition, the level of the reflected financial fees for project financing as follows:

Item Content

Financing Fees

Management Fee 2% of total loan

Agent Fee(Unit: USD 1,000) 50

Commitment Fee 0.15% of undrawdown balance

4.1.2 Estimates of annual total investment

Annual construction schedule provided by POSCO and cumulative EPC schedule are

12.6% for 1st year, 32.4% for 2nd year, 55.8% for 3rd year, 76.8% for 4th year 92.8%

for 5th year and 5.5th should be 100.0%.

Item 2015 2016 2017 2018 2019 2020

Total Project Cost 297 464 514 407 263 98

Interest during construction - - 35 88 115 69

Total Investment 297 464 549 494 377 167

4.2 Operating and Maintenance Expenses

4.2.1 Basic assumption


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O&M costs would be divided into fixed costs and variable costs. Fixed costs

would compose of O&M advisory cost, maintenance cost, land lease fees etc.

and variable costs would compose of maintenance cost, other costs.

Since O&M costs are not generally exceed 1 cent per kWh, we assume 0.55

cents per kWh. This cost is same level when converting to kWh from the

Reference Escalable Capacity Price (RECP), Reference Variable O & M Price in

the Reference.

In addition, the following figure shows the mapping of reference price and O&M

costs in this analysis.

Item Calculated Amount Total Amount (USD 1,000)

Escalable Capacity Price USD 0.00125 per kWh 284

Reference Variable O&M Price USD 0.00425 per kWh 963

Sub total USD 0.0055 per kWh 1,247

Fixed O&M cost USD 0.7745 per kW(Month) 284

Variable O&M cost USD 0.00425 per kWh 963

Sub total 1,247


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4.3 Fuel Cost

4.3.1 Basic assumption

1) Fuel Option

We compared the two types of coal specification and selected one for this

project.

Item GAD5400 GAD5600(GAR5000)

Gross Calorific Value (ADB) 5,400 5,600

Gross Calorific Value (ARB) 4,100 5,000

Total Moisture (ARB) 38% 26%

Inherent Moisture (ADB) 17approx 14approx

Ash (ADB) 7% 10%

Volatile Matter (ADB) 43approx 43approx

Fixed Carbon (ADB) By Difference 33%

Total Sulphur (ADB) 0.8% 1.0%

HGI 60 50

Size 0-50mm 90% 90%

Selection Ⅹ O

The result of comparison is GAD5400 cheaper than GAD5600, however

considering ARB Calorific Value after removing moisture GAD5600 has more

economical value the GAD5400.

Therefore, for analyzing the feasibility, assumed GAD5600 (≒ GAR 5000)

conducted as the fuel.

2) Main assumption

The coal price is assumed USD 100 per ton and this includes the coal price

Daewoo international supply and transportation cost.

Especially, the fuel cost is estimated considering the port for coal imports is

yet constructed so the coal transportation cost expected to be high.

Item Content Amount Remark

Coal

Quantity 327,317 ton per every month Plant capacity factor of 84.6% is considered.

Loading port Samarinda anchorage, East Kalimantan

Price USD 100 per ton Include Carry cost


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4.4 Taxation

4.4.1 Taxation and duties in Bangladesh

Taxations and duties related to power business are VAT and custom duty for

imported goods, insurance on product import, VAT for consumption, and

corporate tax. Tax rates are as follows.

Items Custom Duty General VAT VAT on electric

power consumption Corporate Tax

(Under Govt. List)

Tax rates 0%, 3%, 5%, 12%,

or 25%. 15% 5% 27.5%

Applied Exemption Exemption Exemption 27.5%

(Source: NBR, the central authority for tax administration in Bangladesh)

As per PPA, The Company shall be exempt from any imposition of Taxes on the

sale of Dependable Capacity or Net Energy Output to BPDB under this

Agreement. And, corporate tax rate assumed 27.5%.

4.4.2 Tax holiday

As per PPA, where the Company maintains its existence as a company

organized under the Laws of Bangladesh operating exclusively as a power

generation company, the Company shall, commencing on the Commercial

Operations Date and continuing until the fifteenth (15th) anniversary of the

Commercial Operations Date, be exempt from taxation or withholding tax in

Bangladesh on its income from the sale of Dependable Capacity and Net Energy

Output.(or on any payments received by the Company in lieu thereof).

However, according to the current income tax law (2012-2013, national board of

revenue), there is no tax holiday regulation related to power generation.

Since the tax incentive to power generation is uncertain, we assume that our

company will not be exempted from tax and 27.5% tax will be charged.

<Compare of Tax holiday regulation>

Regulation Details

PPA Exempt from any imposition of Taxes on the sale of Dependable Capacity or Net Energy Output

2011~2012 - Before June 30, 2013 : exempt from tax for 15 years

- From July, 2013: will exempt from tax for 10 years subject to certain limits and conditions.

2012~2013 Not Mentioned


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5. REVENUE ESTIMATION

5.1 Revenue Analysis

5.1.1 Result of Tariff calculation

Item Detail Remark

Levelized Tariff 9.75 US cents /kWh

Reference Capacity Price

RNECP 36.5691 USD per kW-Month

At COD

RECP 0.7745 USD per kW-Month

Reference Energy Price

RVOMP 0.00425 USD per kWh

At COD

Fuel Price 0.04334 USD per kWh

1) Levelized Tariff

Levelized Tariff Charge in US cents/kWh can be calculated in two steps:

a. First, calculate the net present value (NPV) in US cents/kWh of the

Reference Tariffs for all the Contract Years by discounting each of the annual

Reference Tariffs to the beginning of the first Contract Year by using the

discount rate of 12%; and

b. Then, calculate the Levelized Tariff Charge in US cents/kWh that can result

in the same NPV as calculated above for the same discount rate (12%).

2) Reference Capacity Price

The Reference Capacity Price component of the Reference Tariff will be

subdivided in three parts, each payable for one (1) kW of available

Dependable Capacity (DC) in the relevant month:

i) the Reference Non-Escalable Capacity Price or RNECP, expressed in

Dollar per Kw per month, to cover costs of debt servicing, return of equity and

return on equity;

ii) the Reference Foreign Escalable Capacity Price or RECP (US), expressed

in Dollar per kW per month, to cover the fixed costs of operation and

maintenance of the Facility denominated in foreign currencies; and

iii) the Reference Local Escalable Capacity Price or RECP (Tk), expressed in

Taka per kW per month, to cover the fixed costs of operation and

maintenance of the Facility denominated in local currency.


Pre-Proposal

3) Reference Energy Price

The Reference Energy Price component of the Reference Tariff will be

subdivided in three parts, each payable for one (1) kWh of Net Energy Output

(NEO) in the relevant month:

i) The Reference Foreign Variable Operation and Maintenance Price or

RVOMP(US), expressed in Dollar per kWh, to cover variable costs of

operation and maintenance of the Facility denominated in foreign currencies;

ii) The Reference Local Variable Operation and Maintenance Price or

RVOMP(Tk), expressed in Taka per kWh, to cover variable costs of operation

and maintenance of the Facility denominated in local currency ; and

iii) The Reference Fuel Price, payable by BPDB for the Fuel consumed during

operation of the Facility based on the Reference Heat Rates.

4) Constraints on Tariff Charges

Tariff Charges (i.e. Reference Tariff) and components thereof (except as may

result from indexation allowed in the PPA) shall be subject to following

limitations and constraints:

a. Total Reference Tariff and each of its components should be greater than

zero for each Contract Year.

b. Each of the components RECP(US), RECP(Tk), RVOMP(US) and

RVOMP(Tk) must be constant or same across all the Contract Years.

c. Reference Heat Rates quoted for various plant load factors at the

Reference Site Conditions should remain same for the respective load factors

for each Contract Year.

Bidder should account for the heat rate degradation over the Term when

establishing the Reference Heat Rates.

d. Total Reference Tariff in US cents /kWh for the first Contract Year shall not

exceed 111% of the Levelized Tariff Charge.

e. Total Reference Tariff in US cents/kWh for any Contract Year other than

the first Contract Year shall not exceed 110% of the Levelized Tariff Charge.

f. Total Reference Tariff in Taka/kWh levelized over the first ten Agreement

Years (calculated in the similar manner as the Levelized Tariff Charge, except

that the calculation shall be limited to first ten Agreement Years) shall not

exceed 108% of the Levelized Tariff Charge.

g. Escalable Component of the Capacity Price shall not exceed 20% of the

total Capacity Price for any Contract Year and in aggregate. (For the purpose


Pre-Proposal

of expressing total Reference Tariff in US cents/kWh for any Contract Year,

Reference Capacity Price shall be expressed in US cents/kWh by assuming

generation of Net Energy Output during 8760 x 0.846 hours at Contracted

Facility Capacity for the Contract Year.)

<Table of Schedule(Reference Price)>

Year

Reference Capacity Price

Reference Capacity

Price

Reference Energy Price Fuel Cost

(Included Inland Trans. Cost)

Energy Price

Total Reference

Tariff

Non-Escalable Capacity

Price

Escalable Capacity

Price

Escalable Capacity

Price

Variable O&M Price

Variable O&M Price

USD/kW -Month

USD/kW -Month

Tk./kW -Month

USD/ kWh

USD/ kWh

Tk/ kWh

USD/ kWh

USD/ kWh

USD/ kWh

RNECPn

RECP(US)n

RECP(TK)n

RCPn RVOMP

n RVOMP

n 0 REPn RTn

1 2 3 4 5 6 7 9 10

1 36.5691 0.2003 45.9388 0.0605 0.002 0.18 0.0433 0.0476 10.8054

2 35.4355 0.2003 45.9388 0.0586 0.002 0.18 0.0433 0.0476 10.6218

3 34.3370 0.2003 45.9388 0.0569 0.002 0.18 0.0433 0.0476 10.4439

4 33.2725 0.2003 45.9388 0.0551 0.002 0.18 0.0433 0.0476 10.2716

5 32.2411 0.2003 45.9388 0.0535 0.002 0.18 0.0433 0.0476 10.1046

6 31.2416 0.2003 45.9388 0.0518 0.002 0.18 0.0433 0.0476 9.9427

7 30.2731 0.2003 45.9388 0.0503 0.002 0.18 0.0433 0.0476 9.7859

8 29.3347 0.2003 45.9388 0.0488 0.002 0.18 0.0433 0.0476 9.6339

9 28.4253 0.2003 45.9388 0.0473 0.002 0.18 0.0433 0.0476 9.4867

10 27.5441 0.2003 45.9388 0.0459 0.002 0.18 0.0433 0.0476 9.3440

11 26.6902 0.2003 45.9388 0.0445 0.002 0.18 0.0433 0.0476 9.2058

12 25.8628 0.2003 45.9388 0.0431 0.002 0.18 0.0433 0.0476 9.0718

13 25.0611 0.2003 45.9388 0.0418 0.002 0.18 0.0433 0.0476 8.9420

14 24.2842 0.2003 45.9388 0.0406 0.002 0.18 0.0433 0.0476 8.8162

15 23.5314 0.2003 45.9388 0.0394 0.002 0.18 0.0433 0.0476 8.6943

16 22.8019 0.2003 45.9388 0.0382 0.002 0.18 0.0433 0.0476 8.5761

17 22.0950 0.2003 45.9388 0.0370 0.002 0.18 0.0433 0.0476 8.4617

18 21.4101 0.2003 45.9388 0.0359 0.002 0.18 0.0433 0.0476 8.3508

19 20.7464 0.2003 45.9388 0.0348 0.002 0.18 0.0433 0.0476 8.2433

20 20.1032 0.2003 45.9388 0.0338 0.002 0.18 0.0433 0.0476 8.1392

21 19.4800 0.2003 45.9388 0.0328 0.002 0.18 0.0433 0.0476 8.0383

22 18.8762 0.2003 45.9388 0.0318 0.002 0.18 0.0433 0.0476 7.9405

23 18.2910 0.2003 45.9388 0.0309 0.002 0.18 0.0433 0.0476 7.8457

24 17.7240 0.2003 45.9388 0.0300 0.002 0.18 0.0433 0.0476 7.7539

25 17.1745 0.2003 45.9388 0.0291 0.002 0.18 0.0433 0.0476 7.6650

Levelized 30.0513 0.2003 45.9388 0.0499 0.002 0.18 0.0433 0.0476 9.7500


Pre-Proposal

6. FINANCIAL ANALYSIS

6.1 The Basic Conditions

6.1.1 Key factors

Applied key factors, when performed analyzing, are as follows:

ITEM Content Remark

Capacity

Gross Capacity(1,320MW)

Net Capacity(1,223MW)

Annual Generation 9,063.6 MW Plant capacity factor of 84.6% is considered.

Construction Cost EPC Cost : USD1,739,810

Construction Period #1 2016.01.01 ~ 2020.12.31 60Months

Construction Period #2 2016.01.01 ~ 2021.06.30 66Months

Operation Period 2021.01.01 ~ 2046.06.30 25Years

Exchange rate USD 1= 80 TAKA

Equity : Debt 30%: 70%

Interest rate 7.64%

Inflation rate 0%

Levelized Reference Price 9.75 cents per kWh

Coal Price USD 100 per ton Data from Daewoo

International

O&M Costs 0.0055 USD per kWh

Corporation tax rate 27.5%

Tax Holiday 15 years After COD

6.2 Inflation Rate

Past 10 years inflation rate in USA is approximately 2.27%, 6.42% in Bangladesh.

Period USA Bangladesh USA Bangladesh

10 year average 2.27% 6.42%

2.27% 6.42% 5 year average 1.67% 7.23%

3 year average 1.75% 7.36%

(Source: IMF, World Economic Outlook Databases)


Pre-Proposal

Despite the inflation rate, while performing analysis, constant price (assuming 0%

inflation) applied.

Reasons are according to RFP I) Tariff is to be presented in constant price, II)the

financial impact rarely occurs when Tariff levels and O & M costs are match to each

other.

Details

TARIFF

CHARGES

PROPOSAL

a. As per the private Sector Power Generation Policy of Bangladesh and the commercial

terms of the draft PPA, the Bidders are to propose a power tariff for coal operation, as per

format and instructions provided in Section D, Exhibit II, and within the limitations

prescribed below, based on capacity and energy payments.

b. The calculation on which the capacity and energy payment are to be made and their

derivation from the capital structure, financing plan and plant performance shall be shown

explicitly.

c. The proposed Tariff Charges and its components in the Bidder’s Proposal shall be

quoted in Dollar or Taka (as the case may be) to four decimal places, and in real or

constant terms, that is without any indexation allowed in this RFP after the Bid Date

for Exchange Rate, Foreign Index and Local Index.

6.3 Funding

Total investment cost of the project is approximately USD 2,349 million, equity and

debt rate should be 30% of equity and 70% of debt. In addition, analysis assumed

equity capital injection occurs before debt commitment.


Pre-Proposal

(Unit: USD million)

Item Amount Item Amount

EPC 1,740 Equity 705

Other EPC(Include IDC) 609 Debt 1,644

Total EPC 2,349 Total Investment 2,349

6.4 Loan Schedule and Interest Expenses

6.4.1 Terms

Funding plans are as follows:

The interest rate for debt which is borrow form MDB or via agencies in Korea

ECA financing was assumed that, and some of debt raise from the foreign

investors.

Item Content

Repayment period for principal 15 years after COD

Repayment method Even repayment of principal only

Interest rate 7.64%

In addition to the basic financial conditions above, the SPC shall comply with

dividend payment condition until complete repayment of debt. For dividend

payment condition applied normal level condition for project financing, defined as

follows:

Item Content Remark

Debt Ratio Below 300%

Simple DSCR More than 1.2

Cumulative DSCR More than 1.5

6.5 IRR, ROE

6.5.1 Result

Calculated on the basis of the above-mentioned procedure, the Project IRR and

ROE is as follows based on all of assumption mentioned above.


Pre-Proposal

Item Result

Project IRR 15.67%

Equity IRR 19.66%

ROE 15.00%


Pre-Proposal

7. SENSITIVITY

7.1 Results of Sensitivity

7.1.1 Coal price Sensitivity

Results of changes in Coal price are as follows:

Item 80%

of Base Case 90%

of Base Case Base Case

110% of Base Case

120% of Base Case

Coal Price (USD/Ton)

80.00 90.00 100.00 110.00 120.00

Tariff (Cents/kWh)

8.90 9.32 9.75 10.18 10.61

7.1.2 Interest rate Sensitivity

Results of changes in Interest rate are as follows:

Item Base Case -

1.00% Base Case -

0.50% Base Case

Base Case +0.50%

Base Case +1.00%

Interest Rate 6.64% 7.14% 7.64% 8.14% 8.64%

Tariff (Cents/kWh)

9.62 9.68 9.75 9.82 9.89

7.1.3 Coal-Price Sensitivity

Results of changes in Coal price are as follows:

Item Base Case 105%

of Base Case 110%

of Base Case 115%

of Base Case 120%

of Base Case

O&M price (USD/kWh)

0.0055 0.0058 0.0061 0.0063 0.0066

Tariff (Cents/kWh)

9.75 9.78 9.81 9.84 9.86


Pre-Proposal

8. Outline of Plant Configuration

This project is for the development of Bangladesh Chittagong Coal-Fired Power Plant (2

x660MW) (hereinafter referred to as “Chittagong CFPP”) located in the South East of

Bangladesh. The plant will be designed to generate total gross power output of 1,320 MW of

electricity at the generator terminal side and utilize “Ultra Super Critical Technology”

(hereinafter referred as to “USC”).

The power block will consist of two (2) steam turbines to be connected to two (2) steam

generators. Also included are mechanical and electrical auxiliaries and associated

instrumentation and control systems.

In recent years, requests for sustainable use of existing resources and concerns about the

effect of CO2 emissions on global warming have strengthen the focus of plant engineers and

the power industry on more efficient energy conversion process and system.

Coal-based power generation is still a fundamental part of energy supply in account of

reliability, security of supply, low fuel costs, and competitive cost of electricity. But CO2

emissions problem have attracted more and more attention due to its political awareness.

Relatively large CO2 emissions of coal increase the need for more efficient coal-based power

generation.

The efficiency of the power plant affects both the fuel costs and the amount of CO2 emitted to

the environment. Therefore, applying proven state-of-the art technology for optimal

efficiencies are key requirements in new power plant project. Increasing the steam

parameters is a kind of the well-known lever for raising the overall pant efficiency.

Ultra supercritical (USC) steam power plants meet notably the requirements for high

efficiencies to reduce both fuel costs and emissions as well as for a reliable supply of electric

energy at low cost. Recent developments in high-temperature materials also allowed for

significant efficiency gains.


Pre-Proposal

9. Site Information and Environmental requirements

9.1 Proposed Site location

This proposal is based on the following site location which availability shall be

confirmed by the Owner in due course.

1) Location: Matarbari island of Maheskhali Upazila of Cox’s Bazar district

2) Coordinates : To be confirmed later

The proposed site above is surrounded by the Bay of Bengal in the West, Kohelia river

on the East, the designated site of JICA power plant on the north.

9.2 Required Area of the Total Power Plant

The total estimated area for the power plant is about 314 ha that includes Power Block,

Switch yard, Coal Stock yard and Ash Disposal Pond.

However, the exact amount of area can be confirmed at the firm proposal stage when

the systems or specifications of all the facilities are designed in detail.

9.3 Site Layout

The layout planning of the whole area was arranged as follows based on the

circumstantial conditions, and is provided in Figure 9.1.

Proposed Site Layout drawing refers to the Appendix 13.4, Plot Plan.

The north side

The boundary of the north-western limit is fixed under the constraint that it does

not go over the designated site of JICA power plant

- The east side

The boundary of the eastern limit is fixed under the constraint of the existing river


Pre-Proposal

Figure 3.1 Overall Power Plant

9.4 Environmental Requirements

The environmental requirements of the Plant will be in accordance with the applicable

Bangladesh standards, regulations or laws as well as the relevant codes about the

Environmental, Health and Safety Guidelines.

9.4.1 Airborne Emissions

The plant exhaust emissions will not exceed the emission limit of pollutants

shown on Table 9.1. EP and FGD will be installed to meet such limitation.

Table 9.1Emission Limits of Pollutants (1)

Pollutant Unit IFC

Guidelines Bangladesh Standards

Proposed Requirement

NOx mg/m3N 510 600 460

SO2 mg/m3N 850 (2) 820

Particulate Matter mg/m3N 50 150 50

(Source) Environmental, Health, and Safety Guidelines for Thermal Power Plants, IFC 2008 / Schedule 11 and 12, Rule 13, Environment Conservation Rules, 1997


Pre-Proposal

(Note)

(1) The above are based on 6% O2 dry conditions.

(2) At least a 275m height stack is required for dispersion of sulfuric acid.

Regarding the SO2 emission limit, IFC Guidelines state that selection of the

emission level in the range is to be determined by EIA considering the project’s

sustainability, development impact, and cost-benefit of the pollution control

performance.

9.4.2 Noise Emissions

The noise levels will not exceed the standard noise levels mentioned in Table 9.2.

At this stage, the noise limit at the plant boundary cannot be established. It

should be established considering that the noise level of the nearest village shall

be kept within 50 dBA during day time and 40 dBA during night time

Table 9.2 Noise Standards for Industrial Areas

Item Unit IFC Guidelines Bangladesh Standards

Residential Area Industrial Area

Day time dBA 70 (7:00 – 22:00) 50 (6:00 – 21:00) 75 (6:00 – 21:00)

Night time dBA 70 (7:00 – 22:00) 40 (21:00 – 6:00) 70 (21:00 – 6:00)

(Source)Environmental, Health, and Safety Guidelines for Thermal Power Plants, IFC 2008 / Schedule 11 and 12, Rule 13, Environment Conservation Rules, 1997

All measurement of noise and testing will be done in accordance with relevant

code. To comply with the above stated noise criteria, any modifications

necessary, including the installation of additional and/or improved sound

attenuation equipment, will be implemented.

Maximum near field noise will not exceed 85 dB(A) at 1.0m distance and 1.5m

high from the end of each piece of equipment enclosure.

9.4.3 Effluent Limit

The Effluents generated from various sources will be treated and discharged to

sea after meet the standards of IFC(World Bank) Guidelines. A measuring point

of wastewater would be located on the outfall near the battery limit.


Pre-Proposal

Table 9.3 Effluent Guidelines

No. Parameter Unit IFC(W.Bank) Guidelines (Base on)

1 Arsenic (As) mg/l 0.5

2 Cadmium (Cd) mg/l 0.1

3 Chromium (total Cr) mg/l 0.5

4 Chromium (hexavalent Cr) mg/l 0.5

5 Copper (Cu) mg/l 0.5

6 Iron (Fe) mg/l 1.0

7 Lead (Pb) mg/l 0.5

8 Mercury (Hg) mg/l 0.005

9 Oil & grease mg/l 10

10 pH - 6-9

11 Zn (Zn) mg/l 1.0

12 Total Suspended Solid (TSS) mg/l 50

13 Total Residual Chlorine mg/l 0.2

14 Temperature Increase ℃ (*)

(Source) Environmental, Health, and Safety Guidelines for Thermal Power Plants, IFC 2008

(Note) (*) Site specific requirement to be established by the EA. Elevated temperature areas due to

the discharge of once-through cooling water (e.g., 1 Celsius above, 2 Celsius above, 3 Celsius

above ambient water temperature) should be minimized by adjusting intake and outfall design

through the project specific EA depending on the sensitive aquatic ecosystems around the

discharge point.

9.4.4 Sanitary Wastewater

The treated sanitary wastewater quality will meet IFC Guidelines shown in Table

9.4. Septic tanks will be installed to meet such limitations.

Table 9.4 Sanitary Effluent Standards

No. Parameter Unit IFC

Guidelines

1 pH - 6-9

2 BOD mg/l 30

3 COD mg/l 125

4 Total nitrogen mg/l 10


Pre-Proposal

5 Total phosphorus mg/l 2

6 Oil and grease mg/l 10

7 Total suspended solids mg/l 50

8 Total coliform bacteria MPN/100ml 400

(Source) Environmental, Health, and Safety Guidelines for Thermal Power Plants, IFC 2008

(Notes) MPN = Most Probable Number

9.4.5 Environmental Monitoring Facilities

The Continuous Emission Monitoring System (hereinafter called “CEMS”) will be

installed to monitor flue gas from the Plant. CEMS shall be required to monitor

the amount of the flue gas and its concentrations of NOx, SO2, and Particulate

Matter.

The continuous monitoring system for the amount of the effluent from the

wastewater treatment system and its pH value and turbidity shall be monitored.

The monitoring shall be conducted at the treated water pit of the wastewater

treatment system in the Plant.


Pre-Proposal

10. Scope of Supply

This Project basically consists of 2 x 660MW Coal-fired Thermal Power Generation

Facilities, and includes designing, furnishing, constructing, installing, checking, starting-up

and testing of complete operable systems and facilities.

This proposal includes works and services as both EPC contractor and IPP developer’s

responsibility (Chapter 10.1 & 10.2).

However, the items in Out of Scope of Works(Chapter 10.3) below are excluded in this

proposal and shall be supplied by others.

10.1 Scope of Works and Services as EPC Contractor’s responsibility

The EPC Contract requires all of the works for engineering and management,

whenever in these specifications the terms "provide", "furnish", "supply", "furnish

and/or install", etc., are used, its intended that the Contractor shall supply and install

all systems and facilities unless specific notation is made that the equipment, device,

or system is to be installed by others.

The Contract shall also include all works in place from the initial site construction to

start-upend testing as required for complete operable systems and facilities with

Contractor's and Contractor’s Vendors services of technical direction as required for

placing the systems and facilities into successful operation, and for training the

Employer's plant personnel in the operation and maintenance of the systems and

facilities.

The Contractor shall execute checkout, start-up and perform initial operation of

systems and facilities in coordination with the Employer's plant operation staff. The

terminal point of EPC Contractor’s Scope of works refers to Appendix 13.1, Diagram

of Terminal points.

10.1.1 General

1) Project management

2) Engineering services including the following:

A. Project scheduling

B. Conceptual layout and project detailed design

C. Preparation of specifications for equipment and materials

D. Procurement and expediting of all equipment and materials

E. Delivery of equipment and materials to Site


Pre-Proposal

3) Geotechnical Investigations and other surveys of the Site

4) Detailed design of the following

A. Civil and structural systems

B. Architectural systems

C. Mechanical systems

D. Chemical systems

E. Electrical systems

F. Control systems

5) Procurement service of the following

A. Expediting procurement

B. Testing and inspection of equipment

6) Construction services including the following

A. Construction management

B. Construction, equipment erection and installation, labor, labor supervision,

and tools required to implement the engineering designs

C. Construction Equipment

D. Performance testing

E. Startup

F. Construction closeout

10.1.2 Boiler and Auxiliaries

The Works include, but are not limited to, the following equipment / materials:

1) Boiler

2) Coal Bunker

3) Coal Pulverizer

4) Coal Feeder

5) Coal Burner

6) Ignition lighter

7) Start-up Oil Burner

8) Forced Draft Fan

9) Primary Air Fan

10) Soot Blower System

11) Air Heater

12) Induced Draft Fan

13) Electrostatic Precipitator

14) Flue Gas Desulfurizer


Pre-Proposal

15) Stack

16) Fuel Oil Service Tank

17) Fuel Oil Pump

18) Essential Spare Parts as a minimum

19) Tools and Test Equipment

20) Consumable Parts and Material for Commissioning and Initial Operation

10.1.3 Steam Turbine and Auxiliaries


1) Steam Turbine

2) Condenser

3) Steam Turbine Bypass System (High Pressure Bypass)

4) Steam Turbine Bypass System (Low Pressure Bypass)

5) Condenser Cathodic Protection Equipment

6) Condenser Tube Cleaning Equipment

7) Motor-driven Condenser Vacuum Pump

8) Condensate Pump

9) Grand Steam Condenser

10) Condensate Polishing Plant

11) Low Pressure Feed Water Heaters

12) Deaerator

13) Motor-driven Boiler Feed Pump for start-up

14) Turbine-driven Boiler Feed Pump

15) High Pressure Feed Water Heaters

16) Closed Cycle Cooling Water Pump

17) Closed Cycle Cooling Water Heat Exchanger

18) Auxiliary Oil Pump

19) Emergency Bearing Oil Pump

20) Oil Cooler

21) Turning Gears

22) Turning Gear Oil Pump

23) Steam Turbine Supervisory Instrument

24) Essential Spare Parts as the minimum




Pre-Proposal

10.1.4 Coal and Ash Handling Equipment


1) Coal handling equipment (from Coal yard to boilers)

2) Coal Conveyor (from Coal yard to boilers)

3) Stacker / Reclaimer

4) Coal Yard

5) Coal Discharging Conveyer

6) Coal Shifting Conveyor




10) Ash Handling Equipment

11) Furnace Bottom Clinker Handling Equipment

12) Fly Ash Collection Equipment

13) Fly Ash Storage Silo

14) Ash Discharging Conveyor




10.1.5 BOP (Balance of Plant)


1) Auxiliary Boiler

2) Circulating Water Supply System including Screen, Pump and Piping

3) Desalination Plant including Service Water Supply Facilities and Service Water

Tank

4) Demineralization Plant

5) Make-up Water Tank

6) Chemical Injection / Sampling Facilities

7) Service Gas Supply System

8) Compressed Air Supply System

9) Waste Water Treatment Facilities

10) Fire Protection System

10.1.6 Electrical Equipment / Materials


Pre-Proposal


1) Generator and Auxiliaries including Excitation System

2) Generator Circuit System including IPB, VT/ SA and NGR

3) Generator Circuit Switching Devices (GCB and DS with Earthing switch)

4) Generator Step-up Transformer with Auxiliaries

5) Unit Auxiliary Transformer with Auxiliaries

6) 6.6kV Medium Voltage Switchgears with Meters and Protection Relays

7) 415V Unit and Common Switchgears

8) 415V Essential Switchgear

9) Motor Control Center (MCC)

10) Uninterruptable Power Supply Facilities (UPS)

11) Emergency Power Supply Facilities

12) DC Power System

13) Generator and Transformer Protection Relays

14) Cathodic Protection System

15) Power Cables and Wiring Materials

16) Control Cables and Wiring Materials

17) Cable Trays and Fitting Materials

18) Grounding Materials

19) Plant Lighting System

20) Communication System

10.1.7 Instrument and Control Equipment

1) Distributed Control System (DCS)

2) Field Instrumentation

3) Control Valve, MOV and On-off valve

4) Vibration Monitoring System (VMS)

5) Continuous Emission Monitoring System (CEMS)

6) Water & Steam Sampling Analysis System

7) Programmable Logic Control System (PLC)

10.1.8 400kV Switch yard equipment

1) Circuit Breakers (3-phase)

2) Disconnecting Switches (3-phase)


Pre-Proposal

3) Earthing Switches (3-phase)

4) Current Transformers (3-phase)

5) Voltage Transformers (3-phase)

6) Lightning Arresters (3-phase)

7) Control Building

8) Bay Control Unit (BCU)

9) Station Control System (SCS)

10) SCADA (RTU)

11) Protection Relay

12) AC and DC Auxiliary Power System including Battery

10.1.9 Civil, Structure and buildings

The civil works shall include, but not be limited, the following:

1) Site survey(The topography and sea)

2) Soil investigation

3) Site preparation works

4) Site strip and grading

5) Soil banking with slope protection works

6) Soil excavation and backfill

7) Piling and foundation works for all equipment & facilities in the Power Plant

8) Temporary site services (Temporary road, drainage, office etc.)

9) Laydown and contractor’s areas

10) Underground utilities (Electrical duct bank, culvert, trench, piping work etc.)

11) Wastewater treatment system structure

12) Power Plant drainage

13) Road & paving within the site boundary

14) Fence & gate for site security

15) Intake & discharge construction work (If necessary)

16) Coal storage pond & ash storage pond construction work (If necessary)

The structure and buildings Works include, but are not limited to, the following

civil, structures and buildings:

1) Temporary buildings

2) Preliminary works

3) Foundations for pipe racks and pipe support

4) Boiler structures, cladding and stack foundations


Pre-Proposal

5) Turbine building and foundations

6) Electrical building

7) Control room/ office building

8) Workshop and warehouse building, standard equipment and tools for daily

maintenance

9) 400 kV Switchyard control building

10) Water treatment plant building and associated tank foundations

11) Civil works for cooling water system, cooling water intake structures, cooling

water pump house, underground inlet cooling water culvert, underground

cooling water discharge culvert and discharge structures

12) HVAC systems

13) Fire detection system for the Plant

14) Electrical installations of the buildings, small power systems, indoor normal,

emergency and exit lighting for the Plant's buildings

15) Service platforms and structures, lifting beams and lifting devices for Plant

equipment in order to facilitate daily operation and maintenance

16) Offices and Facilities for the Employer’s Engineer at Site as specified by the

Employer

10.1.10 Spare part, special tool

1) Spare part for startup / commissioning

2) Special tool for construction / maintenance

10.1.11 Site training for Owner’s Employee

1) Steam turbine and Generator

2) ESP

3) DCS Control & Instrumentation

4) Demineralization Plant

5) Coal and Ash Handling

6) Electro-chlorination Plant

7) Seawater Cooling System

8) Fire Fighting System

9) Emergency Diesel Generator System

10) Compressed air / instrument air


Pre-Proposal

10.2 Scope of works and services as IPP developer’s responsibility

1) Land for Power Plant, Coal yard and Ash pond Site office, Lay-down and

warehouse areas for the Contractor including Sub-contractors

2) Getting all necessary permissions(including environmental permits) for

construction, erection and operation of the plant from Authorities of Republic

of Bangladesh Government

3) Labor Cost and Site Expenditure for the Owner’s staff during construction

and Commissioning before COD

4) Costs of travel or stay of the Owner’s engineers for factory inspection and

test at the Contractor’s shop or those of his sub-contractor

5) Shop (Overseas) training for Owner's Employee, if necessary

6) Material for Pre-commissioning, Commissioning and tests Consumer

A. Coal

B. Ignition Diesel Oil

C. Water

D. Electric

7) Insurance

A. Project Cargo (Including Marine Cargo)

B. EAR (Erection All Risk)

C. Worker's Compensation / Employer's Liability

D. Others for Owner side

8) Customs Duty (regarded to be exempted in this proposal)

9) 2 Years Spare Parts

10) Power Sale during Reliability Test

10.3 Out of Scope of works to be provided by Others

1) 400KV Transmission line from New Switchyard to National Grids

2) Jetty Facilities, Port & Harbor

3) Access Way (Road & Bridge) to the site

4) Land acquisition and Permissions and construction cost for Access Road

5) Coal Handling system and coal transfer (from coal supplier to coal yard)


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11. Design Description

11.1 Tentative Design Criteria

In accordance with data from several metrological data sources, the Plant shall be

designed according to Table 11.1 Design Criteria. The Minimum Ambient Dry Bulb

Temperature was obtained by statistical treatment of daily minimum temperatures of

January from 1992 to 2011 at the Kutubdia observation station. The Maximum

Ambient Dry Bulb Temperature was obtained by statistical treatment of daily minimum

temperatures of April and May from 1992 to2011 at the Kutubdia observation station.

The Design Ambient Dry Bulb Temperature was obtained using the above 20 years

data as typical conditions. The Annual Rainfall was obtained from the above 10 years

data (from 2002 to 2011) at the Kutubdia observation station. Design Ambient Dry

Bulb Temperature, Relative Humidity and Design Sea Water Temperature at Turbine

Maximum Continuous Rating (TMCR) conditions are 30℃, 80% and 30℃,

respectively. The design conditions were determined tentatively according to the

limited metrological data in order that these could be revised during the design stage.

Table 11.1 Tentative Design Criteria

Design Ambient Dry Bulb for Performance Guarantee

30℃

Relative Humidity for Performance Guarantee

80%

Design Sea Water Temperature (TMCR/TBN Capability)

30℃ / 32℃

Minimum/Maximum Relative Humidity 20% / 100%

Minimum/Maximum Ambient Dry Bulb Temperature

15℃ / 35℃

Barometric Pressure 0.1013 Mpa

Elevation 10m+ M.S.L. for Power Block Area

Sea Water Level High Water Level = +2.2m M.S.L Low Water Level = -2.2m M.S.L

Seismic Criteria* 0.28 (Zone 3)

Wind Design* 72.2 m/s (Chittagong)

Annual Rainfall 4877 mm

Maximum Rainfall Rate (1 hour)* 85 mm/hr

Snow Load 0 kg/m2

(Source) *:Bangladesh Notional Building Code 2010, Others: Assumption


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Table 11.2 summarizes tentative specification of Design Coal. The caloric value (HHV)

of imported coal is 5,000kcal/kg and it is used for this proposal.

Table 11.2 Tentative Specification of Design Coal

Gross Calorific Value (ADB, kcal/kg) 5,600

Gross Calorific Value (ARB, kcal/kg) 5,000

Total Moisture (ARB, %) 26 %

Inherent Moisture (ADB, %) 14 %

Ash (ADB, %) 10 %

Volatile Matter (ADB, %) 43 %

Fixed Carbon (ADB, %) 33 %

Total Sulphur (ADB, %) 1.0 %

HGI 50

Size 0-50 mm 90%

Table 11.3 Seawater Analysis

No. Contaminants Units Seawater

1 pH - 7.7

2 Temperature ℃ 32

3 Turbidity NTU 12

4 Conductivity ㎛ hos/cm 84103

5 Total suspended solids mg/l 18

6 Total dissolved solids mg/l 33000

7 Total alkalinity as CaCO3 mg/l 216

8 Total hardness as CaCO3 mg/l 9376

9 Ca hardness as CaCO3 mg/l 571

10 Mg hardness as CaCO3 mg/l 1921

11 Chloride mg/l 37135

12 Sulphate mg/l 4145

13 Sodium mg/l 21270

14 Potassium mg/l 872

15 Fluoride mg/l 0.7

16 Nitrate as N mg/l 2.8


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No. Contaminants Units Seawater

17 Total Phosphates mg/l 0.18

18 Chemical oxygen demand mg/l Appx.50

Table 11.4 Redundancy apply for main equipment

No. Item Redundancy

1 Condenser 1x100% / Unit

2 Condensate pump 3x50% / Unit

3 Condensate polishing plant 1x100% / Unit

4 Gland steam condenser 1x100% / Unit

6 High Pressure Heater#1 1x100% / Unit



9 Deaerator 1x100% / Unit

10 Boiler feed water pump(Turbine Driven) 2x50% / Unit

11 Boiler feed water pump(Motor Driven, Start-up) 1x25% / Unit

12 Low Pressure Heater#1 1x100% / Unit




16 CCW Pump 2x100% / Unit

17 CCW Head Tank 1x100% / Unit

18 CCW Heat Exchanger 2x100% / Unit

19 Main cooling water Pump 2x50% / Unit

20 Auxiliary cooling water pump 1x100% / Plant


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Fig. 11.1 Basic wind speed map of Bangladesh

(Source: BANGLADESH NATIONAL BUILDING COD 2010)


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Fig. 11.2 Seismic Zoning Map of Bangladesh

(Source : BANGLADESH NATIONAL BUILDING COD 2010)


Pre-Proposal

Table 11.5 Seismic Zone Coefficient Z for Some Important Towns of Bangladesh

Town Z Town Z Town Z Town Z

Bagerhat 0.12 Dinajpur 0.20 Kushtia 0.20 Panchagarh 0.20

Bandarban 0.28 Faridpur 0.20 Lalmanirhat 0.28 Patuakhali 0.12

Barguna 0.12 Feni 0.20 Madaripur 0.20 Rajbari 0.20

Barisal 0.12 Gaibandha 0.28 Manikganj 0.20 Rajshahi 0.12

Bhola 0.12 Gazipur 0.20 Mongla 0.12 Rangamati 0.28

Bogra 0.28 Habiganj 0.36 Munshiganj 0.20 Rangpur 0.28

Brahmanbaria 0.28 Jaipurhat 0.20 Mymensingh 0.36 Satkhira 0.12

Chandpur 0.20 Jamalpur 0.36 Narsingdi 0.28 Sirajganj 0.28

Chittagong 0.28 Jessore 0.12 Natore 0.20 Srimangal 0.36

Chuadanga 0.12 Khagrachari 0.28 Naogaon 0.20 Sunamganj 0.36

Comilla 0.20 Khulna 0.12 Netrakona 0.36 Sylhet 0.36

Cox's Bazar 0.28 Kishoreganj 0.36 Noakhali 0.20 Tangail 0.28

Dhaka 0.20 Kurigram 0.36 Pabna 0.20 Thakurgaon 0.20

(Source : BANGLADESH NATIONAL BUILDING COD 2010)

11.2 Expected Plant Performance

The expected plant performance at TMCR conditions are summarized in Table 11.6.

Table 11.6 Expected Plant Performance

Gross Power Output (kW) at TMCR 2 x 660,190 kW

Net Power Output (kW) 2 x 611,807 kW

Gross Efficiency, HHV (%) 42.02 %

Gross Heat Rate, HHV (kJ/kWh) 8567 kJ/kWh

Note 1. TMCR : Turbine Maximum Continuous Rating

2. The above performance results are expected based on the design criteria in chapter 5.1

11.3 Codes and standards

All Project equipment and systems shall be designed, constructed, inspected, installed

and tested as appropriate at the manufacturer’s works, after installation and during


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commissioning in accordance with the latest relevant International codes, standards

and accident prevention regulations. Full name of the code and standard are as below.

Code Name Full Name

AASHTO American Association of State Highway and transportation Officials

ABMA American Boiler Manufacturers Association

ACI American Concrete Institute

ACRI Air-Conditioning and Refrigeration Institute

AISC American Institute of Steel Construction

AISE Association of Iron and Steel Engineers

AISI American Iron and Steel Institute

ANSI American National Standards Institute

API American Petroleum Institute

ASCE American Society of Civil Engineers

ASHRAE American Society of Heating, Refrigeration & Air Conditioning Engineers

ASME American Society of Mechanical Engineers

ASTM American Society of Testing and Materials

AWS American Welding Society

AWWA American Water Works Association

BNBC Bangladesh National Building Code

BS British Standards Institute

CEMA Conveyor Equipment Manufacturers Association

CEN European Committee for Standardization

CENELEC European Committee for Electro technical Standardization

CL Chlorine Institute

CMAA Crane Manufacturers Association of America

CSRI Concrete Reinforcing Steel Institute

DEMA Diesel Engine Manufacturers Association

DIN Deutsches Institute fur Normung

EHS IFC Environmental Health and Safety Guidelines

EN Euro Norm

GB GuoBiao, Chinese national standards

HEI Heat Exchange Institute

HIS Hydraulic Institute Standard

IAPH International Association of Ports and Harbours


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Code Name Full Name

IBC International Building Codes

IEC International Electrotechnical Commission

IEEE Institute of Electrical and Electronics Engineers

IP Institute of Petroleum

ISO International Organization for Standardization

JIS Japanese Industrial Standards

KS Korean Standards

MS Malaysia Standard, Manufacturer’s Standard, Industrial Ventilation

MSS Manufacturer’s Standardization Society

NACE National Association of Corrosion Engineers

NEMA National Electrical Manufacturers Association

NFPA National Fire Protection Association

OSHA Occupational Safety and Health Administration

SSPC Society of Protective Coatings (formerly known as Steel Structures Painting Council)

TEMA Tubular Exchanger Manufacturers Association

TRD Technical Rules for Steam Generators

UBC Uniform Building Code (USA)

UFC Uniform Fire Code

UPC Uniform Plumbing Code

VDI Verein Deutscher Ingenieure

VGB Society of Large Utility Owners

WFCF Water Pollution Control Federation

• Loads and Stresses

All civil and structural design will be in accordance with ASCE 7, “Minimum

Design Load for buildings and other structures”.

• Structural Steel

Steelwork for structures will be designed according to the American Institute of

Steel Construction (AISC, Specification for the design, fabrication and erection of

structural steel for buildings).

• Reinforced Concrete

Structural concrete works will be designed in accordance with the following

codes/standards:


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- ACI 318 Building code requirements for reinforced concrete

- ACI 301 Specification for structural concrete for buildings

- ACI 315 Building code requirements for detailing reinforced concrete

structures

Materials for Civil & Architecture

a) Concrete

Minimum concrete compressive strength fck at 28 days of cube specimen will be

as follow:

fck, MPa Area of Use

16 Lean concrete

27 Structures and equipment foundations

40 Marine facilities

b) Reinforcing Steel

The reinforcing steel will conform to the requirements of ASTM Designation A615

Grade40, Grade60.

11.4 Submission Requirements

This proposal shall be in the English language. The International Systems International

d ’Units (“SI”) system of units (metric) in accordance with the provisions of ISO 31 and

ISO 1000 shall be used in the proposal.

Quantity Name of Unit Symbol

Length Meter m

Mass Kilogram Kg

Time Second S

Temperature Degree Celsius C

Electric current Ampere A

Area Square meter m2

Volume Cubic meter m3

Force Newton N

Pressure Bar bar


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Pressure below 1 bar Millibar mbar

Stress Newton per square millimeter N/mm2

Velocity Meter per second m/s

Rotational Speed Revolutions per minute Rpm

Flow

Cubic meter per day Cubic meter per hour Kilogram per hour Liter per second metric ton per hour For gaseous substance: standard cubic meter per hour (referred to 0 °C and 1013 mbar)

m3/d m3/h kg/h l/s t/h Nm3/h

Density Kilogram per cubic meter Kilogram per standard cubic meter

Kg/m3 Kg/Nm3

Torque, moment of force Newton meter Nm

Work, energy or heat Joule J

Power, radiant flux Watt W

Heat release rate Watt per square meter W/m2

Surface Tension Newton per meter N/m

Concentration Parts per million Ppm

Frequency Hertz Hz

Electric Potential Volt V

Conductance Siemens S

Luminous Flux Lumen Lm

Energy Kilowatt hour kWh

Fuel (Energy) Kilocalorie gram per Kilogram Kcal/kg

11.5 Boiler and Flue Gas Treatment Facilities

Boilers and flue gas treatment facilities for this project shall be composed of two

boilers, two electrostatic precipitators, and a flue gas desulfurization system, and their

auxiliary equipment, each of which is associated with each of the two condensing type

steam turbines of 660 MW generation capacities.

(1) Boilers

The two boilers shall both be pulverized coal firing, radiant reheat, and variable


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pressure once-through boilers for outdoor installation. Each boiler will be designed

as a balanced draft furnace with low NOx burners. About 1,835.0 ton/hr ultra

supercritical main steam (258 bara, 603.8 ℃ at boiler outlet) are generated. The

design criteria of the boilers are shown in Table 11.7.

Table 11.7 Boiler Design Criteria

Type Pulverized coal fired, single reheat, once-through, Ultra Supercritical, (Outdoor Installation)

Steam Flow Rate at TMCR - Main Steam - Reheat Steam

1920.0 ton/hr 1550.8 ton/hr

Steam Pressure at TMCR - Superheater Outlet - Reheater Outlet

258.0 bara 52.0 bara

Steam Temperature - Superheater Outlet - Reheater Outlet

603.8 ℃

602.4℃

Fuel Pulverized coal, light oil or high speed diesel oil for unit start up, and ignition and stabilization of coal burners

Drafting System Balanced draft with forced draft fans and induced draft fans

The boiler will be designed for pulverized coal firing and fuel oil will be used for

igniters and initial warm up for unit starting up. The boiler shall have corner or

opposite fired, radiant- and convection- heat transfer superheaters and reheaters,

attemperators, economizers, regenerative air heaters, and a HP/LP turbine bypass

system.

(2) Primary Air Fan, Forced Air Fans

Each boiler primary air fans (PAF) and capacity forced draft fans (FDF) for

supplying the required primary/secondary air for the boiler. These fans would be of

axial flow type with variable pitch moving blades.

(3) Induced Draft Fans

Each boiler will be equipped with induced draft fans for keeping the draft of the

furnace at slightly reduced pressure to prevent flue gas leakage. These fans would

be of axial flow type with variable pitch moving blades.


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(4) Boiler Circulation Pumps

There will be a boiler circulation pump. The purpose of this pump is to return water

drained from the water separator to the inlet of the economizer and recover the

heat during the operation at low load.

(5) Soot Blowing System

The boiler shall be provided with soot blowers and wall blowers. The entire soot

blower operations shall be carried out from the DCS of the plant control system. An

intelligent automatically controlled operation system will be applied for the soot

blower system.

(6) Burner Management & Automatic Plant Control Systems

The boiler will be equipped with a complete burner management system including

mill automation and secondary air control with all required accessories as detailed

in the DC System (Control and Instrumentation).

(7) Mills & Milling System

Each boiler will be installed with mills. It would include one standby for the

pulverized coal firing system for enhanced reliability. Each mill has a gravimetric

raw coal feeder. The pulverized coal from each mill is transported through several

pulverized coal pipes to the burners. The burners are arranged for tangential firing

or opposite firing.

(8) Electrostatic Precipitators

The flue gas dust collection system for each boiler will consist of a two pass

electrostatic precipitator (ESP). The electrostatic precipitator ash collection

hoppers will have a capacity sufficient for required hours operations at the

maximum collection rate in any section of the electrostatic precipitator. The ESPs

will be provided complete with motorized or magnetic rapping mechanisms,

rectifier transformers, hoppers and their heaters and all associated auxiliaries. The

hopper outlet will be provided with a diversion gate for Dry Fly Ash collection

System. The ESP will be capable to limit dust emission, with the worst coal having

the maximum ash content.

(9) Flue Gas Desulfurization System (FGD)


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FGD will reduce SO2 in flue gas to satisfy Bangladesh regulations and the

international standards, including the WHO. SO2 concentration in flue gas entering

FGD will be estimated for the worst coal condition (sulphur content of 1.0 Air

dry %). Seawater Temperature rise through FGD will be 2 ~ 3 deg C. If alkalinity of

Seawater is found insufficient than expected after detail seawater analysis, NaOH

dosing for FGD is might be required to control (guarantee) the pH of SWFGD

effluent.

For this project, Seawater FGD is recommended with the following reasons:

- Since Seawater FGD uses seawater as an absorbent of SO2, a handling system

and pulverizing system of limestone are not required.

- Since no byproducts such as gypsum is produced, a dewatering, storage and

delivery system and disposal area are not required.

- Because of the above reasons, project costs and land area will be extremely

reduced.

Seawater FGD for each boiler of this project shall consist of the following

equipment/facilities:

-Sulfur dioxide absorbers

-Regenerative gas-gas heaters (GGH)

-Seawater boost up pumps

-Seawater pipes and valves

-Flue gas bypass system (bypass duct and bypass damper)

-Inlet and outlet flue gas ducts

-Air blowers for aeration

-Aeration pond

-Instrumentation and control system

11.6 Steam Turbine and Auxiliaries

The steam turbine plant will be comprised of a steam turbine, condenser, condensate

equipment, feed water heaters, boiler feed pumps and condenser circulating cooling

water system as the fundamental configuration.

11.6.1 Steam Turbine


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The steam cycle system will be a single reheat, ultra supercritical, condensing

type required for high efficiency and a large-size power plant. The steam cycle is

of ultra-supercritical pressure considering that the unit size is 660 MW class.

Tandem compound shaft configuration would be applied in this project. High

pressure (HP), intermediate pressure (IP) and low pressure(LP) steam turbines

are connected in the same shaft.

The latest design for the last stage blades (LBS) of the LP turbine also would be

applied to contribute to high efficiency and decreasing investment costs.

11.6.2 Condenser

In thermal power plants, the purpose of a surface condenser is to condense the

exhaust steam from a steam turbine into cycle water (steam condensate) so that

it is reused in the boiler as boiler feed water.

There are many fabrication design variations depending on the manufacturer, the

size of the steam turbine, and other site-specific conditions.

A single pass-one division of tube and shell circuit schematics is preferable, even

for condenser types for large-sized turbines, being based on the HEI (Heat

Exchange Institute) standard.

The required amount of cooling water for the condenser is calculated by the

following formula.

Gw = Q/(δtd x cpxρ)

Where,

- Gw :The required amount of cooling water for the condenser [m3/h]

- Q: Incoming heat to condenser [kcal/h]

- δtd: temperature difference of cooling water between inlet and outlet of

condenser [°С]

- cp: specific heat of cooling water [kcal/kg °С]

- ρ: specific gravity of cooling water [kg/m3]

Based on the data of an Appendix 13.4, heat balance diagram, the total required

amount of cooling water was estimated at 93,562ton/h for one unit.

Titanium would be applied to condenser tubes and tube sheet cladding material

concerning corrosion by sea water.

11.6.3 Condensate pump

A condensate pump is a specific type of pump used to extract the condensate


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(water) in the hot-well of a condenser. Condensate pumps, as used in hydraulic

systems, are usually motor-driven centrifugal pumps.

In a thermal power plant, the condensate pump is normally located adjacent to

the main condenser hot-well, often directly below it.

These pumps are used in succession to provide sufficient Net Positive Suction

Head (NPSH) to prevent cavitation and the subsequent damage associated with

it.

11.6.4 Condenser Polishing Plant

A USC plant does not have function of boiler water blow and however it requires

high quality of boiler feed water so that a condensate demineralizer shall be

installed after the condensate extraction pumps. Contaminants in the condensate

water are colloidal matters of iron and coppered, sodium ion and chloride ion. In

some case the condensate demineralizer is to equip filters to remove colloidal

matters. After the filters the condensate demineralizer has ion exchangers for

dissolved matters.

11.6.5 Condenser Vacuum

The estimate for a condenser vacuum such as 0.087bara (saturated temperature

43°С) is done on the basis of the method provided in the HEI standard.

On the one hand, the condenser vacuum depends on the actual measurement

data of seawater temperature, and the vacuum has been studied on the basis of

a design seawater temperature of 30.0°С at the condenser inlet in accordance

with Table 11.1, tentative design criteria.

The cooling water facilities will be designed so that discharged water temperature

will be 37°C, which is not considered problematic since the temperature is not

higher than 40°C.

11.6.6 Vacuum system

For water-cooled surface condensers, the shell’s internal vacuum is most

commonly supplied and maintained by two types of vacuum systems, such as

steam jet type air ejectors and motor driven vacuum pumps.

The motor driven vacuum pumps are preferable on the basis that they are more

serviceable.


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11.7 Feed water system

11.7.1 Deaerator

A deaerator is a device that is widely used for the removal of air and other

dissolved gases from the feed water to steam-generating boilers. In particular,

dissolved oxygen in boiler feed waters will cause serious corrosion damage in

steam systems by the oxidizing of surfaces of metal piping and other metallic

equipment. Water also combines with any dissolved carbon dioxide to form

carbonic acid that causes further corrosion. Most deaerators are designed to

remove oxygen down to levels of 7 ppb by weight (0.0005 cm³/L) or less.

From technical (efficiency and operation, etc.) aspects and cost aspects, tray-

type and spray-type deaerators are considered the main options for selection.

11.7.2 Boiler feed pump

A boiler feed pump is a specific type of pump used to pump feed water into a

steam boiler. Theater may be freshly supplied or returning condensate produced

as a result of the condensation of the steam produced by the boiler.

These pumps are normally high pressure units that use suction from a

condensate return system and can be of the centrifugal pump type. Turbine

driven type will be applied for Boiler feed pump in account of reliability at plant

start-up.

11.7.3 Feed water heater

Feed water heaters are applied to improve thermal efficiency. The source of

heating is the extracted steam from the turbine. The number of heaters is

determined considering economic benefits such as improved efficiency and

additional investment costs, etc. In general, six to eight heaters are installed for

large scale power plants over 200MW.

11.7.4 Heat exchanger

A heat exchanger is a device built for efficient heat transfer from one fluid to

another. The fluid may be separated by a solid wall, so that they are never mixed,

or they may be in direct contact. Heat exchangers may be classified according to

their flow arrangement. In parallel-flow heat exchangers, two fluids enter the

exchanger at the same end, and travel in parallel to the other side. In counter-


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flow heat exchangers the fluids enter the exchanger from opposite ends. The

counter-flow design is more efficient, in that it can transfer the most heat from the

heat (transfer) fluid.

- Types of heat exchangers

The shell and tube heat exchanger is the most common type of heat exchanger

in large coal fired power plants, and is suitable for higher-pressure applications.

This type of heat exchanger consists of a shell (a large pressure vessel) with a

bundle of tubes inside of the shell. One fluid runs through the tubes, and another

fluid flows over the tubes (through the shell) to transfer heat between the two

fluids.

- Shell and tube heat exchanger

Feed water is at a high pressure so that a shell and tube heat exchanger is

applied. In this case, feed water flows inside of the tube and extracted steam and

its condensate flows outside of the tube. There can be many variations on the

shell and tube design. Typically, the tubes are bent in the shape of a U (called U-

tubes) and the ends of each tube are connected to water boxes divided by a

partition sheet.

U-tube heat exchangers are the most common type of heat exchanger in coal

fired power plants and will be applied in this project.

- Selection of tube material

To be able to transfer heat well, the tube material should have good thermal

conductivity. Because heat is transferred from the hot to cold side through the

tubes walls, there is a temperature difference through the width of the tubes.

Because of the tendency of the tube material to thermally expand differently at

various temperatures, thermal stress occurs during operation. This is in addition

to any stress from high pressures from the fluids themselves. The tube material

should also be compatible with both the shell and tube side fluids for long periods

under the operating conditions(temperatures, pressures, pH, etc.) to minimize

deterioration of the tubes, such as corrosion.

All of these requirements call for a careful selection of strong, thermally-

conductive, corrosion-resistant, high quality tube materials, typically metals,

including copper alloy, stainless steel, carbon steel, non-ferrous copper alloy,

Inconel, nickel, has tally and titanium. Materials would be chosen in consideration


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of fluid handled. An inadequate selection of tube material might result in a leak in

the tube between the shell and tube sides causing fluid cross-contamination and

possibly loss of pressure.

11.8 Coal and Ash Handling System

11.8.1 Coal Handling System

The coal is transferred to the coal yard via trucks or any other methods by others.

Coal in the coal yard is handled by stackers/reclaimers. Portable device could be

used in case of unserviceability of stackers/ reclaimers.

(1) Consumption of the Coal (Design Conditions)

The coal yard is assumed to be an open type. The storage nominal capacity of the

coal yard is specified to meet coal consumption for required days (incl. margin)

with continuous operation with a capacity factor of 100% of two units at the rated

output. The number of days for storing the quantity of the coal takes a margin of 20%

into consideration, assuming that receiving coal by others may be prevented for

about 80% of required days a year due to the interference of cyclones every year.

(2) Nominal Capacity of the Coal Yard

The coal yard is of open type. The storage nominal capacity of the coal yard is

specified to meet the coal consumption for approximately 60 days of continuous

operation with a capacity factor of 100% of two units at the rated output. The

number of 60 days for storing the quantity of the coal takes a margin of ten days

into consideration, assuming that receiving coal by others may be prevented for

about 24 days a year due to the interference of cyclones every year.

(3) Nominal Capacity of the Stackers/Reclaimers

a) Nominal Capacity of the Stackers

Stackers will be provided with proper capacity to pile coals for storage.

b) Nominal Capacity of the Reclaimers

The coal handling system is planned to be operated continuously for 24 hours.

The nominal capacity of the reclaimer is estimated so that the required amount

per day of coal can be supplied in required hours.

c) The number of the Stackers/Reclaimers

The number of stackers/reclaimers shall be several sets in consideration with


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operability, and they will be installed between respective piles.

(4) Nominal Capacity of the Discharge Conveyor

The capacity of the discharge conveyor has to be designed so as to meet the

capacity of their reclaimer with a margin. It is a definite requirement that the unit

has to be continuously operated even if one discharge conveyor is out of order.

For this purpose, the number of discharge conveyors must be two, including one

spare.

Moreover, the type of the conveyer will be a ground type that can be easily

inspected.

(5) Conveyor Type Selection

The flat type conveyor will be applied to this project. After the plot plan is

determined in the detailed design stage, the conveyor specification will be given

further consideration.

11.8.2 Ash Handling System

In general, ash in coal is captured in various parts in the flue gas flow in the course of

the combustion of coal in the boiler until the flue gas is discharged from the stack.

- The ash which is melted by the coal combustion falls to the bottom hopper of the

boiler furnace and is captured. This is called clinker. About 10 - 20% of the amount

of all ash is captured in this way.

- A part of the combustion ash which floats in the flue gas falls to the bottom hopper

of the economizer and the air heater in the downstream of flue gas and is captured.

This combustion ash is called cinder ash. 5% or less of the amount of all ash is

captured here.

- The combustion ash which is captured by the electrostatic precipitator is caught in

the bottom hopper of the electrostatic precipitator. It is called fly ash. In general, 80

- 90% of the amount of all ash is captured here.

The collected coal ash is generally transported and processed through ash handling

systems that may be roughly categorized into two systems as follows.

- The first system handles clinker that falls to the bottom hopper of the boiler and the

pyrite exhausted from the coal pulverize.

- The second system handles the cinder ash and fly ash that falls to the bottom


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hopper of the economizer, air heater and electrostatics precipitator.

(1) Bottom Ash Handling System

The water sealed drag chain system handles clinker ash that falls to the bottom

hopper of the boiler and the pyrite exhausted from the coal pulverizer. The clinker

that falls to the bottom hopper of the boiler is collected using the water sealed

conveyor and is dehydrated for transport to a bottom ash bunker for temporary

storage. The pyrite flows into the bottom of the ash bunker. The clinker ash and

pyrite are transported to the ash disposal pond by belt conveyer or trucks in order

to keep the power station roads clean.

(2) Fly Ash Handling System

The vacuum – pneumatic system handles the cinder ash and fly ash that falls to

the bottom hoppers of the economizer, air heater and electrostatic precipitator. The

cinder ash and fly ash are transported to intermediate ash silos using a vacuum

and transported from intermediate ash silos to the fly ash silos for temporary

storage using compressed air. Finally, the fly ash is transported to the ash disposal

pond by belt conveyer or trucks in order to keep the power station roads clean.

(3) Nominal Capacity of the Ash Pond

The nominal capacity of the ash disposal pond is calculated based on the total

volume of the ash to be accumulated for the total operating duration with 80%

capacity factor of two units.

Various studies have been conducted regarding effective utilization of coal ash

produced in large quantities in the boiler, and the following uses have proven

practical.

- Clinker: road bed material

- Fly ash: material for cement, concrete aggregate, road pavement, fertilizer

11.9 Cooling water system

Circulating water system supplies cooling water from sea to condenser, and also

transfers from condenser to sea using circulation water pump (CWP). CWP is

installed near the sea intake system, and the pump supplies necessary circulating

water flow for heat transferred by condenser, CCCW cooler and condenser vacuum

pump cooler.

4 x 25% CWP per plant which is vertical type driven by motor shall be installed. The


Pre-Proposal

equipment will be located outdoor and subject to the environmental conditions.

Each pump intake structure is prepared per the recommendation of the design

standard of the Hydraulic Institute Standards. The facilities will be designed to meet

the specified intake structures design conditions.

The intake structure for purification of intake seawater consists of four (4) x 25%

chambers of screening channel. It will be provided with traveling band screens, bar

screens, and a stop log. Each channel will be interconnected by an opening of

division wall of intake structure at CW inlet chamber of intake structure.

11.10 Stacks

Stacks are a common facility for Units 1 & 2.

(1) Foundation

The foundation is of a mat foundation (shape octagonal) type

(2) Concrete windshield

The windshield is made of reinforced concrete. It protects the inner flues form

wind-force, seismic-force and other forces.

(3) Inner flues

The cast able lining type is selected for this project from the viewpoint of the

availability and cost of the material.

- Cylinder: Two cylinders (an extension of the cylinder of Unit 2 is expected in the

future)

- Material: SS400

(4) Platform and ladder

Ten platforms are set up inside the windshield for maintenance of the stack.

A ladder is also set up inside the windshield for access to the platforms.

(5) Ventilation system

Natural ventilation is provided for maintaining the inside temperature during

maintenance in good conditions.

(6) Aeronautical light

An aeronautical light system and aircraft warning light will be provided based on

the regulation.

(7) Lightning

Lightning protection will be set up on the top of the stack.

11.11 Civil Works


Pre-Proposal

11.11.1 Site Preparation work

11.11.1.1 Survey and Geotechnical Soil Investigation

1) Site Surveying

Topographical survey will be conducted to verify the existing site condition

Survey works will include the following.

- Triangulation & Traverse Survey

- Leveling Survey

2) Hydro-Oceanographic survey

Most thermal power plants are usually located along the coastlines to provide an

adequate source of cooling water for the plant. As a result, potential damage from

oceanographic events must be reviewed. Protection against these events must be

incorporated into the design to ensure plant safety and uninterrupted plant

operation.

The major hydro-oceanographic event which must be considered during plant

design consists of astronomical tide, wind wave, current and so on.

The purpose of these surveys is to check the safety by over the oceanographic

events.

- Tidal level observation

- Tidal current observation

- Buoy tracking

- Measurement of temperature, collection of soil under/on the sea bed

- Measurement of salinity, sea/soil resistivity for cathodic protection

- Simulation for wind wave prediction (Design wave)

- Simulation for Thermal diffusion prediction

- Simulation for bottom sediments transport prediction

- Bathymetric survey


Pre-Proposal

3) Geotechnical Soil Investigation

The Main purpose of geotechnical soil investigation is to explore the subsurface

stratigraphy and to obtain foundation design criteria and construction

recommendations.

- Field Investigation

- Boring

- Sampling

- In-situ test

- Laboratory

- Index property test

- Structural property test

- Chemical property test

11.11.1.2 Determination of Site Elevation

The existing site ground level is supposed to be +1.0m M.S.L. And according to

the record of storm surge in Bangladesh, the actual surge height observed in

period of near 50 years is 7.6m (April 1991, Chittagong Patenga).Based on that,

the Site Elevation is determined as below H.W.L + 50 year return period of

previous highest record = 2.2m M.S.L + 7.6m M.S.L = 9.8m M.S.L => +10.0m

M.S.L

Figure 11.3-1 Plant Embankment level


Pre-Proposal

Embankment will be executed from the existing ground level to the determined

level.

The amount of embankment shall be determined after receiving site layout and

topographic survey data.

11.11.1.3 Soil improvement

The existing ground strata is supposed to be very soft as the typical soil condition

of other neighboring seaside in Bangladesh.

The purpose of soil improvement is to increase the shear strength of the soil, to

reduce the soil compressibility and the permeability of the soil prior to construction

and completed plant load, and prevent potential damage to the structures by

Differential settlements.

If the embankment is completed, the probability of consolidation settlement and

circular slip are very high. The vertical drain method is generally used as an

improvement method. But the method of soil improvement shall be determined

after geotechnical investigation. The features of potential vertical drains methods

are as below.

Table 11.8-1 Features of vertical drains

Item PBD

(Plastic Board Drain)

PSD

(Pack Sand Drain)

Illustration

Advantage

. Deep Penetration (>50m)

. Rapid installation

. Low Cost

. Low well resistance

. Rapid installation

(4or 6 drains simultaneously)

Disadvantage

. Decrease of discharge capacity

(3yr)

. Deterioration by hot

competition

. shallow penetration (<30m)

. High cost relatively

. Poor penetration in sharp

transition


Pre-Proposal

Table 11.8-2 Features of vertical drains

Item SD

(Sand Drain) FD

(Fiber Drain)

Illustration

Advantage

. Good penetration into stiff layer

. High discharge capacity in long

term

. Hard to sever by lateral force

. Environment- friendly

Disadvantage

. Difficulty in sand supply

. High cost

. Slow installation

. Rare practices

. High cost relatively

. Uncertain hydraulic properties

11.11.2 Intake and Discharge

11.11.2.1 General

The Once-through cooling system will be adopted where cooling water is taken

from the sea and moved to condenser for heat exchange and then discharge back

again to the sea.

The civil part of primary components in cooling water system consists of the

following;

Sea water Intake conduit velocity cap

Sea water Intake conduit

Sea water Intake structure

Seal pit

Discharge system

Outfall

11.11.2.2 Sea water Intake Conduit Velocity Cap

The sea water intake conduit velocity cap can be installed at a near point of

offshore.

The safety screen bar will be installed in the entrance of intake basin to exclude

various life stages or fish or other aquatic organisms.


Pre-Proposal

The Intake Head is precast concrete structure build on the ground and placed in

target position with caution. It should be connected to intake pipeline and protected

by Armor stone surrounded.

11.11.2.3 Sea water Intake conduit

The sea water intake conduit can be used pipe or concrete box. As an aspect of

processing period, pipe is suitable to use.

Figure 11.3-2 Figure of Conceptual Intake with a velocity cap headworks

11.11.2.4 Sea water Intake structure

The intake structure is concrete structure and constructed so that it can maintain

the minimum water level and supply the sufficient amount of water to the pump

under L.W.L sea water level condition.


Pre-Proposal

Figure 11.3-3 recommended intake structure layout [ANSI/HI 9.8-1998]

Figure 11.3-4 Filter wall details for proper bay width [ANSI/HI 9.8-1998]


Pre-Proposal

11.11.2.5 Seal pit

Primary function is to prevent the influx of air at the discharge conduit and to

maintain the siphon head at the condenser.

Upstream head height above weir crest to maintain siphon head should be

considered backwater and overflow water depth for the minimum flow rate. Seal pit

structure will be a reinforced concrete structure.

11.11.2.6 Discharge system

The open channel type of surface discharge system along the shoreline might be

suitable. And the dispersion study of the discharge water shall be conducted to

confirm the sea water temperature conditions.

11.11.2.7 outfall

The outfall will be a reinforced concrete structure.

At the outfall natural spreading occurs due to diffusion of turbulence with an angel

of about 10˚ related to the axis of the discharged jet. The mean velocity is reduced

accordingly. When the outlet structure opening is steeper than this diffusion anger,

no reduction of the flow will take place (see Fig. 11.3-5). In this case calming

elements are required (sea Fig 11.3-6).

Figure 11.3-5 Velocities at outfall structure with surface discharge


Pre-Proposal

Figure 11.3-6 Hydraulic concept of forced spreading at outlet structure

Figure 11.3-7 Flow Diagram of Cooling Water System


Pre-Proposal

11.11.2.8 Building and Equipment Foundation

The foundation type will be applied on the shallow foundation or deep foundation

according to result of soil investigation. And the foundation will be designed per the

requirements of the American Concrete Institute ACI318 “Building Code

Requirements for Reinforced Concrete”.

The shallow foundation is unit that provides support for a structure by transferring

loads to soil or rock at shallow depths (Such as strip, pad grillage, mat foundation

etc.). The load transfer is primarily through shear resistance of the bearing strata.

Table 11.8.3 Type of shallow foundation

Strip foundation(Wall footing) Pad foundation

Grillage(Beam) foundation Mat foundation

The deep foundation is unit that provides support for a structure transferring loads

by end bearing and/or by shaft resistance at considerable depth below the ground

(Such as pile foundation, slurry wall etc.).


Pre-Proposal

The foundation will be designed to keep the maximum soil or rock pressures within

safe bearing values. To prevent unequal settlement footing will be designed to

keep the bearing pressure as nearly uniform as practical.

Final design of all site development and foundation type will be based on the

results of a comprehensive subsurface investigation program.

Table 11.8.4 Type of deep foundation

Pile foundation Slurry wall

For purposes of design, every structure and foundation will be designed to resist

the overturning, hydrostatic uplift, and sliding effects caused by applied forces.

Stability analyses will be performed by superimposing all appropriate loads for

each of the conditions being investigated in accordance with standard engineering

practice as governed by applicable codes and standards.

a) Sallow foundation stability: Use only service loads to resist the applied forces. Use

minimum factors of safety as follows:

- Minimum factor of safety against compression failure : 3.0

- Uplift (wind, seismic or hydrostatic) : 2.0

- Overturning (wind, seismic, or other) : 1.5

- Sliding (wind, seismic, or other) : 1.5

b) Bearing Capacity: Maximum bearing pressure will not be greater than the

allowable bearing pressure. Equipment foundation deflection (settlement) will be

limited to a maximum of 25 mm (1.0-inch) of total deflection. More stringent

deflection (settlement) criteria shall be used as required for a proper installation

and /or to comply with equipment manufacturer’s criteria.


Pre-Proposal

c) Deep Foundations stability

- Compression – Minimum factor of safety : 3.0

- Uplift – Minimum factor of safety : 2.0

- Reduce pile or drilled shaft capacities to account for spacing and group effects.

- Foundations resisting lateral loads shall be designed to maintain lateral deflections

below limits which will not create detrimental lateral deflection of the structure or

equipment supported thereon.

- Verification of the allowable capacity of piles will be determined by full-scale

field load tests performed prior to installing production piles.

11.11.3 Road & Paving

The road will be located throughout the plant and central to load. Some lighting

may be installed.

Roads are classified in two classes. Road widths, radius of corners, curves and

pavement will be designed to be entirely suitable for the sizes of vehicles.

We propose two road types as shown in the table below.

Table 11.8.5 Type of deep foundation

Road type No. of Lanes(m) Minimum radius(m)

TYPE-A 8.0 10.0

TYPE-B 6.0 10.0

Type-A roads will consist of two 3.00 meter asphalt pavement lanes. The main

plant roads will be type-A roads.

Type-B roads will consist of one 4.00 meter asphalt pavement lane. Access

roads to equipments and buildings will be type-B roads.

The cross slope of the road will be 2.0% and maximum grade of road will be 5%.

The road pavement structure of the particular road sections will be designed

based on the expected maximal weight and size of the components / material to

be delivered or transport from the plant. And will be designed for AASHTO.

11.11.4 Site Drainage

a) General Description of Storm water Drainage System

The plant will be provided with the following runoff drainage systems:

- Clean storm water runoff


Pre-Proposal

- Oil-contaminated runoff and discharges

- Chemical contaminated runoff and discharges (plant process waste)

b) Clean storm water runoff

Open surface drains will be used to convey clean storm water from the ditch

and underground storm water piping. Typical clean storm water flows

include runoff from road, grassed areas, building roof drains.

c) Oil-contaminated runoff

An Oil/Water Separator System will be provided to collect discharges from

the following sources:

- Outdoor oil pumping areas

- Maintenance shop

- Transformers

d) Chemical contaminated runoff

Contaminated storm water runoff is storm water collected from areas that

contain hydrocarbons or chemicals and is directed to the wastewater

treatment system. Typical areas requiring collection of contaminated storm

water runoff include the following:

- Hydrocarbon and chemical storage areas

- Fuel storage areas

- Sewage treatment

e) The sanitary wastes are collected by gravity whenever possible.

Wastewater is treated to the required criteria for the final disposal.

11.12 Building List

No. Building List

1 Turbine Building (including T/G FND.)

2 Main Control Building

3 Warehouse

4 Water & Waste Water Treatment Building

5 Administration Building

6 FGD Control Building

7 Switchyard Control Building

8 Electro-chlorination Building

9 Coal Handling Control & Switchgear House

10 Guard House

11 Service Gas Storage Shelter


Pre-Proposal

11.13 Electrical Equipment

11.13.1 Conceptual Design of the Unit Electrical System

The configuration of the power plant consists of two boilers, two steam turbines

and two generators. Each generator shall be connected to the Generator Step-

Up Transformer (GSUT) by an Isolated Phase Bus duct (IPB) respectively. The

voltage of the power output from the generator shall be stepped up to 400kV by

GSUT. The output from the GSUT shall be transmitted to the Bangladesh

network via the 400kV switchyard located next to the power plant area.

A generator main circuit breaker located at the GSUT low voltage side shall be

introduced. Therefore, each generator shall be synchronized with the

Bangladesh network by a generator circuit breaker located at the GSUT low

voltage side respectively.

The design criteria for configuration, size and rating of components of the unit

auxiliary power distribution system are as follows:

1) A single event (either a planned or forced outage of a piece of equipment) shall

not cause the loss of the generating unit, but may lead to reduced output of the

unit.

2) For voltage levels 400V and above, except for the case of single-ended

switchgear, it shall be possible for any switchgear power supply to transfer

safety either automatically or manually as applicable from one source to the

alternate source under normal operating conditions, without having to black-out

the switchgear.

3) Loss of the transformer (other than the generator step-up transformer and

excitation transformer) shall not lead to an output of the generating unit. The

failure of a unit transformer may cause the loss of the generating unit until such

time as the faulty unit transformer is isolated and the unit can be restarted from

a healthy transformer.

4) Loss of the switchgear bus bar, normally fed from the unit transformers shall

lead to a power output reduction of generation less than 50% and shall not

cause a loss of the generating unit.

Each unit shall be provided one three-winding Unit Auxiliary Transformers (UAT)

and branched from the generator main circuit by IPB connection.

The UAT shall be connected to the two unit 6.6kV switchgears and the two


Pre-Proposal

common 6.6kV switchgear via a circuit breaker respectively via a circuit breaker

respectively.

Both of the unit 6.6kV switchgear and the common 6.6kV switchgear shall be

interconnected via a circuit breaker respectively.

During the unit operation, the power source to the unit auxiliary loads shall be

fed from the generator output via a unit auxiliary transformer. During the unit

shut down and the unit start up, the power source to the unit auxiliary loads

shall be fed from the 400kV switchyard via the startup transformer.

Before de-synchronizing the generator, the power source to the unit auxiliary

loads shall be transferred from the unit 6.6kV switchgear to the common 6.6kV

switchgear, and after synchronizing the generator, the power source to the unit

auxiliary loads shall be transferred from the common 6.6kV switchgear to the

unit 6.6kV switchgear.

11.13.2 Generator

The overview requirements of the generator are shown below

Item Specification

Number of generators 2 (unit 1 and unit 2)

Type Three phase field rotating synchronous

Number of poles 2

Number of phases 3

Rated output 660MW

Rated frequency 50Hz

Rated speed 3,000rpm

Rated terminal voltage Manufacture’s standard (18 – 25kV)

Power factor 0.80 (lagging), 0.95 (leading)

Short circuit ratio Not less than 0.5

Cooling method Water or H₂gas direct cooling for stator coil

H₂gas direct cooling for rotor coil

Type of excitation system Static or brushless excitation system


Pre-Proposal

11.13.3 Transformer

1) Generator step-up transformer (GSUT)

The GSUT shall be oil immersed type and shall be fitted with On Load Tap

Changer (OLTC) on the high voltage winding, having a range sufficient to

allow for the voltage variation at transmission voltage (400kV) and the

transformer regulation.

The GSUT shall be provided with Oil Natural Air Forced (ONAF) cooling.

The GSUT shall be rated to match the generator output.

2) Unit Auxiliary Transformer (UAT)

The UAT shall step down the voltage from the generator terminal voltage to

6.6kV, to provide power supply to the unit auxiliaries.

The UAT shall be oil immersed and shall be fitted with On Load Tap Changer

(OLTC) on the high voltage winding with automatic voltage regulator, having a

range sufficient to allow for the voltage variation at generator terminal voltage

and the transformer regulation.

The UAT shall be provided with Oil Natural Air Forced/ Oil Natural Air Natural

(ONAF/ONAN) cooling.

Sizing of the UAT shall be based on the total unit load.

11.13.4 Generator Circuit Switching Devices

The generator circuit breaker and the disconnecting switches with earthing

switches shall be provided at the low voltage side of the GSUT for the generator

synchronization with the Bangladesh network.

11.13.5 Unit Electric Supply

The unit electric supply shall be configured from unit auxiliary transformer. The

unit load for plant operation shall be powered from the unit transformer and the

common load for plant operation, such as water handling, waste water handling;

coal handling, etc.

Moreover, as an electric power source for emergencies, one set of diesel

engine driven generators shall be provided for the purpose of safety shut down

of the unit.

11.13.6 6.6kV Unit and Common Metal Clad Switchgears


Pre-Proposal

Two sets of 6.6kV unit metal clad switchgears and two sets of common 6.6kV

metal clad switchgears shall be provided for power supply to the unit auxiliary

loads and the common auxiliary loads.

Each unit switchgear and each common switchgear shall be powered from the

unit auxiliary transformer secondary winding respectively.

The unit switchgear and the common switchgear shall be interconnected via

bus-tie circuit breaker respectively for the purpose of a back-up power supply

vice versa.

11.13.7 415V Unit and Common Switchgears

Several 415V unit and common switchgears shall be provided for power supply

to the unit auxiliary loads and the common auxiliary loads.

Each switch gear shall be powered from 6.6kV switchgear via 6.6kV/415V low

voltage transformer respectively. The unit switchgear and the common

switchgear shall also be interconnected via bus-tie circuit breaker respectively

for the purpose of a back-up power supply vice versa.

11.13.8 400kV Switchyard

400kV switchyard shall be provided next to the power plant area for delivery of

the generating power to the Bangladesh network. This switchyard will be

interconnected with the Bangladesh network by two circuits of new 400kV

transmission lines.

a) Design Concept

In order to maintain the reliability of the switchyard, the 400kV bus bar system

shall preferably be double bus with 1+1/2 circuit breaker configuration of outdoor

type.

The switchyard shall be designed to be able to connect six circuits, consisting of

two circuits for transmission lines, two circuits for unit 1 and Unit 2. The circuit

breaker shall be the type of gas insulation breaker (GCB) and the disconnecting

switch shall be the type of air insulation switch (AIS).

This switchyard is owned by PGCB and the control and monitoring of this

switchyard equipment shall be done from NLDC by remote control.

Quantity of main equipment


Pre-Proposal

The quantity of the main equipment is as follows:

Circuit Breakers (3-phase) 6 sets

Disconnecting switches (3-phase) 16 sets

Earthing Switches (3-phase) 16 sets

Current Transformers (3-phase) 12 sets

Voltage Transformers (3-phase) 4 sets

Lightning Arresters (3-phase) 2 sets

In addition to the above, other equipment including the control equipment is

required. The switchyard equipment shall be controlled and monitored from NLDC

by remote control through the Substation Control System (SCS) located in the

switchyard.

Equipment and its location

Control building at the switchyard

Bay Control Unit (BCU) In the control building at the

switchyard or switchyard

Station Control System (SCS) In the control building at the switchyard

SCADA (RTU) In the control building at the switchyard

Protection relay in the control building at the switchyard

AC and DC auxiliary power in the control building at the switchyard

System including battery (power source will be fed from the

power plant)

11.14 Instrument and Control

The intent of the control and instrumentation specifications is that integrated system will

be installed allowing highly automated, centralized control and monitoring of the whole

Plant from the control systems Hyman-Machine Interfaces (HMI) located in a Central

Control Room (CCR). For reference purpose in this specification, this system will be

referred to as the DCS.

11.14.1 System Configuration of the instrumentation and control system

The DCS will be a distributed, microprocessor-based system for boiler


Pre-Proposal

combustion and miscellaneous modulating control systems (CCS); burner

management system (BMS); & boiler protection system (BPS); motor control

system (MCS); LCD-based operator interface; configured and complete with all

system equipment and programs, hardware and software, and all related

equipment and appurtenances to meet the functional and operational

requirements, as hereinafter specified.

The scope of supply will include design, manufacture, hardware selection,

assembly, control optimization, configuration, programming, documentation,

testing, training, information transfer, delivery, spare parts/special tools, and

field services as required.

The DCS will include communication links for interfaces to the following:

• PLC-based Systems and Micro processor-based Systems (e.g.coal handling,

water treatments, ESP, etc.)

• Load Dispatching–Power

• Plant Master Clock with GPS

• Turbine control system

• Continuous emission monitoring system

• Vibration Monitoring and Analyzing System

• Etc.,

1) Technical Requirement

a) System Configuration

The DCS will be distributed functionally to the greatest possible extent. The

segregation for each of the two (2) units DCS will be as follows:

• Motor control/sequential logic (MCS)

• Boiler combustion controls (CCS)

• Burner control furnace safety system (BMS) & boiler protection system (BPS)

• Interface with other systems

b) System Communication

A dual redundant data highway (network) will be used to transmit data among

stations. Both data highways will be in continuous operation. Fiber optics will be

utilized to the greatest extent possible.

Fault-tolerant redundant data highway communication system including data


Pre-Proposal

communication interfaces with other control and monitoring system.

All hardware, software and responsibility for the establishment of digital data

communication link of DCS and other control systems such as STG and BOP

auxiliary systems, etc. The data communication networks are designed so that

the communication speed is sufficient to support control and monitoring function

for the interface system.

c) Operator Interface, Graphics, and LCD-Based

All DCS control, monitoring, and diagnostic functions will be available

through the DCS operator interface.

The operator workstation will allow use of multi-tasking, multi-user operating

systems that provide the real-time deterministic response required for process

control applications. The workstations will support standard LAN protocols such

as Ethernet TCP/IP or similar.

Operator's workstation will be composed of color LCD monitors and keyboards.

During performing functional operations by the operator, the procedure will be

as simple as possible and concise information of the procedure will be

incorporated with the LCD display. Through the operator's workstation the

operator will be able to command all printers and other peripheries.

d) Historical Data Collection, Storage and Presentation

A Historical Data Collection, Storage and Presentation (Historian) System will

fully automate the collection, storage and presentation of plant data. The

Historian will provide a centralized collection of information, a real-time

database and a historical data archive. The Historian will interface with all of the

plant real-time systems simultaneously and will be capable of reading and

writing to these systems. The system will store to an adequately sized storage

medium with a printer and necessary software.

2) Integrated Engineering Work Station

EWS(Engineering Workstation) function is the following:

• For fault finding, programming facilities such as boiler, steam turbine and BOP

• Test, configure process interface modules/cards

• Generate control software through logic diagram

• Diagnostic programs

• Fault detection through diagnostics


Pre-Proposal

3) DCS function of the Power Plant

• The DCS shall have the following functions:

• Plant interlock system

• Boiler control system

• Burner management system

• Turbine control system

• Plant auxiliaries interlock and sequence control system

• Data acquisition historical storage and retrieval system

11.14.2 Control and Operation Philosophy

During normal operation the main operator functions will be selection and

supervision of the appropriate Plant configuration to meet the electrical load targets.

Start-up and normal shutdown of the Plant will remain directly under the operator’s

control by management and coordination of the start-up and shutdown sequences of

the various plant areas. Automation of the Plant start-up sequences for individual

Plant areas will be provided. The Plant controls must also automatically manage

between different load cases without excessive deviation from the various set

points for load demand signaled from the load dispatcher to the Plant DCS.

1) Plant Automation

The degree of automation is to be such that the total time required for

starting/stopping, the quality of key control parameters, and the protection of the unit

shall be made by the automation equipment, not by the operator intervention.

All the operations required from the preparation of plant start up such as operation

of circulating water system, auxiliary steam system, clean up condensate system,

etc., to the rated load and vice versa without interruption, for loading, unloading and

governing transient conditions shall be fully automated.

The startup/shutdown procedures including draining and venting of the plant shall be

selectable and controlled automatically according to the plant status such as restart,

hot start, warm start and cold start respectively.

Also, to minimize the operation procedures in starting and stopping, efforts shall be

made by the Supplier to simplify the design consistent with the need for any special

components to facilitate boiler/turbine temperature matching.

The starting and stopping procedures of the plant are to be divided into some break

points at which operator intervention is required to make procedures to the next


Pre-Proposal

operation stage. When the plant automation system is failed, normal operation of the

plant shall be still available by operator from central control room.

The Plant's instrument and control systems shall be designed to provide for the

reliable safe and efficient start-up, operation. shutdown and emergency shutdown of

the Plant and its auxiliaries. The Plant DCS shall be the primary operational,

monitoring and controlling point for all installed equipment including STG and other

equipment furnished with PLC or other proprietary control systems.

2) Design Conditions

The instrumentation and control equipment will fulfill the general technical

requirements. The type and make of equipment will be internationally proven in

steam power plants. The plant instrumentation and control equipment will be

selected and designed in such a way that the following functions will be performed

for each power unit.

a) Automatic start-up of the unit, automatic boiler ignition and loading, turbine

rolling-up, generator synchronizing and turbine generator loading up to the

preselected load.

b) The automatic start-up procedure will also include all unit auxiliary equipment.

c) Unit automatic start-up will be accomplished by hierarchical function group

control system in coordination with automatic analogue control system.

11.15 Water and Wastewater Treatment System

11.15.1 Desalination plant and Water treatment plant

Service water is utilized as the source of demineralized water for boilers,

cooling water for equipment, ash disposal and firefighting, etc.

There is no source of fresh surface water in the vicinity of the site, and

underground water is no suitable to draw a sufficient amount of water given

possible adverse effects, such as the drying up of wells in the vicinity of the site

and subsidence of the ground.

Therefore, a desalination plant is required to produce service water

The desalination plant and demineralization plant will treat sea water by

reaction and coagulation, pretreatment (DAF or equiv.), Multimedia Filter (MMF),

SWRO system, Ion Exchanger and Mixed Bed Polisher(MBP) system.


Pre-Proposal

The sea water is supplied to pretreatment system by sea water feed pump. The

sea water is passes through coagulation and pretreatment system for the

removal of particulate organic and colloidal material. And then treated sea water

by pretreatment system is transferred to MMF filter for removal of suspended

solids.

The filtered water is supplied to cartridge filter by the demi system feed pumps,

and then to the SWRO unit by SWRO high pressure pump for desalination.

Permeate from SWRO will be used as service water, potable and firefighting

water.

Desalinated water will be used to produce potable water. To sterilize the water,

hypochlorite will be applied. And rest of desalinated water from SWRO unit is

transferred to Ion Exchanger and MBP system for demineralization. The brine

water from the SWRO unit is discharged directly to the discharge pond to the

sea. The regeneration waste water from demineralization plant is discharged to

the abnormal waste water storage pit.

Desalination system and Water treatment plant will have controls and

monitoring functions for each stream during operation and chemical cleaning

process. System will have provisions of control locally.

System compositions

• Desalination Plant

- Pretreatment (DAF or equiv.) system

- Pre-treated water pond

- Multimedia Filter system (MMF)

- 1’st filtered water tank

- SWRO unit

- CIP (Cleaning) system

- Chemical injection system for SWRO

- Desalination water storage tank

The desalinated water will be further demineralized in Ion exchanger (2B3T)

and MBP system as the make-up water supply to demineralized water


Pre-Proposal

consumers.

The finally treated water by demi water system is managed by silica,

conductivity value and flow transmitter where treated water is transferred to

demineralized water tank.

The demineralization system will be complete with a chemical injection and

storage system consisting of sodium hypochlorite, sodium hydroxide,

hydrochloric acid, assorted chemical dosing pumps and mixing agitators, etc.

The water designated to feed the power plant will be supplied from sea. The

characteristics related to the seawater are presented in following table. This

seawater analysis is only reference. Any change in the sea water analysis will

affect the design.

Note) This proposal is based on the above seawater analysis data.

Under the above operating conditions the final quality of the demineralized

water will meet the following (this value have been assumed. If necessary, it will

be changed later) ;

• Silica, mg/l as SiO2 : less than 0.02

• Conductivity, μS /cm : less than 0.2

• pH : 5.5 – 7.5

The demineralization plant will be housed indoors and have controls and

monitoring functions for each stream during operation and regeneration process.

System compositions

• Demineralization System

- Ion exchanger (2B3T)

- Mixed bed exchanger

- Regeneration system

- Chemical injection system for demineralization plant


Pre-Proposal

11.15.2 WASTE WATER TREATMENT PLANT

The waste water originating from the power plant can be classified into three

categories such as normal waste water, abnormal waste water and oily waste

water.

The waste water generated from each source of the power plant will be

collected to the wastewater storage pit and then will be treated by the pH

control method with chemical and sedimentation method.

The capacity of the wastewater system will be in accordance with Contractor’s

water balances and will be designed system capacity

The normal wastewater is generated from desalination system and water

treatment system, sump pits of power plant, etc. Normal wastewater will be

collected in the Normal waste water storage pit. Wastewater is equalized and

mixed by aeration in the pit, then it will be transferred to clarifier for wastewater

via pH reaction tank, coagulation tank. The wastewater will be neutralized in the

pH reaction tank by means of acid and caustic dosing which is controlled pH

analyzer located on pH reaction tank. After pH adjustment, chemical of

coagulant and coagulant aid will be injected in coagulation tank in order to

flocculate particulates, organics and etc. The floc is settled in a clarifier and

clarified water is stored in clarified water pit via monitoring pit and it will be

discharged to WWT effluent pond.

The abnormal wastewater from water and wastewater treatment area by

regeneration/cleaning process and power block during overhaul period will be

collected in the abnormal wastewater storage pit near the water treatment

building. The wastewater is neutralized in this pit by acid or caustic. And then

the wastewater is equalized and mixed by aeration then transferred to a normal

wastewater storage pit. The wastewater is equalized and mixed by aeration in

the wastewater storage pit.

The oily wastewater is generated from the G.T Area sump pit, TR Area sump pit,

etc.

The oily waste is transferred into the API oil separator. Oil is removed in the API

oil separator and CPI(Corrugated Plate Separator) oil separator and treated

water flows into the normal wastewater storage pit.


Pre-Proposal

Treated water from wastewater treatment plant is transferred into the WWT

effluent pond. And then it will be reused for Coal handling spray water and Ash

handling spray water in site or discharged to the discharge pond.

The sewage treatment system consisting of septic tank type, compact

purification facility complete with pumps, drives, storage tank including all

auxiliaries and all accessories shall be supplied.

The sludge transferred from the clarifier by means of a sludge transfer pump for

clarifier will be thickened in the thickener, and then thickened sludge will be

delivered to dehydrator in order to make the sludge cake. The sludge cake is

collected in a cake box. Wastewater from the dehydrator is returned to the

normal wastewater storage pit.

C-Polymer pumped by a C-polymer dosing pump and sludge pumped by the

sludge transfer pump are mixed in control compartment on the sludge-mixing

tank for sludge conditioning. After conditioning, the readily drainable water is

separated from the sludge by a dehydrator.

System compositions

• Waste water treatment system

- Normal waste water storage pit

- Abnormal waste water storage pit

- API & CPI Oil Separator

- Oily storage pond

- pH adjustment, Coagulation, Flocculation Tank with agitator

- Clarifier with reducer & scraper

- Sludge Thickener

- Sand filter & A/C filter (if necessary)

- Dehydrator facilities

- Chemical feed system (for WWT)

- PLC based control system

11.16 Firefighting system

11.16.1 General


Pre-Proposal

A water spray system is recommended as it is quickly effective for the local

cooling extinguishment of fires. And it is generally used for firefighting systems

of thermal power plants in which there is the possibility of the spread of fire due

to heat from the continuous fire of the plant. The Fire Fighting System will be

equipped with the following specialized fire alarm and hydrocarbon firefighting

systems as a minimum requirement for one unit.

11.16.2 Application of Fire Fighting System

1) Fire Water Tank

2) Fire Water Pumps

3) Fire Water Network

4) Fire Hydrants and Hose Boxes

5) Sprinkler Systems

6) Water Spray Systems

7) Foam Systems

8) FM-200 (HFC-227ea) Systems

9) Carbon Dioxide (CO2) Extinguishing Systems

10) Portable Fire Extinguishers

11) Fire Alarm Systems

11.16.3 Standard

Firefighting activities for the main building are to be undertaken in accordance

with the acting security norms, standards and regulations for power plants of

Bangladesh, and facilities shall be designed on the basis of NFPA standards.

NFPA10 Standard for Portable Fire Extinguishers

NFPA11 Low, Medium, and High Expansion Foam

NFPA12 Carbon Dioxide Extinguishing System

NFPA14 Standard for the Installation of Standpipe and Hose Systems

NFPA15 Standard for Water Spray Fixed Systems for Fire Protection

NFPA20 Standard for the Installation of Stationary Pumps for Fire Protection

NFPA30 Flammable and Combustible Liquid Code

NFPA850 Electric Generating Plants and High Voltage Direct Current Converter

Station

NFPA2001 Clean Agent Fire Extinguishing Systems


Pre-Proposal

11.16.4 System Description

1) Fire Water Tank

The fire water for firefighting is stored in the fire water tank. The total

capacity of the firefighting water is determined based on the requirements

and recommendations of NFPA 850 and capable of supplying for two (2)

hours at a maximum fire water demand, which covers the largest fire water

demand plus operating of two (2) hydrants.

2) Fire Water Pumps

The fire water is taking suction from the storage tank by the fire pumping

system installed within the fire pump house to be located adjacent to the

storage tank. The fire pumping system consists of one (1) 100 % duty

electric motor pumps and one (1) 100 % stand-by diesel engine driven pump.

The rated flow of fire pumps shall be determined in compliance with NFPA

20. The diesel engine driven fire pump is provided with a 12 hours fuel

supply tank, starter batteries, controls, exhaust and silencer. The fuel supply

tank is installed external to the pump house.

In order to prevent the activation of the main fire pump due to minor leaks

causing fluctuations in pressure, two(2) electric motor driven jockey pumps

are provided, and connected to the system. The duty of the units shall be as

small as to allow that, in the event of pressure drop in the fire ring main, the

main fire pump is immediately brought into operation.

3) Fire Water Network

The firewater piping network is sized to provide the design firewater demand

to each area of the facility.

4) Fire Hydrants and Hose Boxes

Above ground, fire hydrants will be provided throughout the plant. All

buildings, structures and equipment will be within reach of hose streams from

two hydrants while hydrant spacing generally will be not be greater than 90m

or as required by NFPA Code, whichever is the more stringent.

Each hydrant will be provided with a post-indicator valve in its connection to

the fire water ring main.

5) Sprinkler Systems


Pre-Proposal

Sprinkler systems will be provided in accordance with NFPA 13. Design

parameters will be in accordance with the recommendations of NFPA 850.

6) Water Spray System

Water spray systems will be provided in accordance with NFPA 15. Design

parameters will be in accordance with the recommendations of NFPA 850.

7) Foam Systems (Foam Chamber and Foam Monitor)

Foam systems will be provided in accordance with NFPA 11.

8) FM-200 (HFC-227ea) Systems

FM-200 systems will be provided in accordance with NFPA 2001.

9) Carbon Dioxide (CO2) Extinguishing Systems

CO2 systems will be provided in accordance with NFPA 12.

10) Portable Fire Extinguishers

Portable fire extinguisher, based on dry chemical/powder or CO2 depending

on the fire risk, shall be provided in all the buildings.

11.16.5 Fire Alarm Systems

A fire detection system is provided whose main functions are the actuation of

the extinguishing systems and the annunciation, both centralized and local, of

alarms and systems status. The system includes fire detectors in all the

protected areas and monitored by the installation of the following types of fire

detectors:

1) Temperature rate of rise detectors, for the areas with higher fire risk

2) Optical type smoke detectors, where slow combustion fires are possible with

consequent smoke release

11.17 HVAC system

11.17.1 General

The Scope of Work includes all necessary Heating, Ventilation and Air


Pre-Proposal

conditioning (HVAC) equipment including Plant, controls, instrumentation,

interlocking and cabling systems necessary to maintain appropriate ambient

conditions for equipment and personnel.

11.17.2 Ambient Temperature

Summer design conditions 33. 3℃ DB / 27. 8 ℃ WB

Winter design conditions 11.1℃ DB / 6.4 ℃ WB

11.17.3 Indoor Design Conditions per Each Building

The indoor room conditions are to be set for heating, ventilation and air-

conditions system design as per ASHRAE or process needs.

11.17.4 System Description

1) Air Conditioned Areas

The air-conditioned areas shall be provided with Air Handling Units or

Packaged Air Cooled DX-Units.

2) Ventilated Areas

Ventilated areas will be provided with mechanical ventilation. Roof mounted

exhaust fan, ventilated wall mounted supply and exhaust fan, duct in-line fan,

air intake louver shall be applied.

11.17.5 HVAC Control

The HVAC control system shall be supplied with DDC or microprocessor based

temperature /humidity control system to control and monitor the operation of

HVAC equipment.

In addition, the controller should perform remote (on/off) operation, fault alarm

record temperature, humidity and pressure readings, and control time-schedule.


Pre-Proposal

12. Operational Requirements

12.1 General

The main components and their auxiliaries shall be designed to ensure that trouble

free starts and operations are achieved throughout the design life of the plant.

Adequate redundancies for auxiliary facilities and equipment shall be made available

to achieve high availability. The main components and their auxiliaries shall be

designed to be able to start and rise up to full load byte initiation of a single push

button. The entire plant shall be suitable for continuous power load operation.

12.2 Plant Duty

1) Cold start

2) Warm start

3) Hot start

4) Black start (Not applicable)


Pre-Proposal

13. Appendix

13.1 Diagram of Terminal points

13.2 Heat Balance Diagram

13.3 Water balance diagram

13.4 Plot Plan

13.5 Single line diagram

13.6 Control system configuration

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