CHAPTER I

PAGE

\CONTENTS

CHAPTER TITLEPAGE NO.

IINTRODUCTION

01

IIEXECUTIVE SUMMARY

03

IIINEED AND JUSTIFICATION FOR THE PROJECT10

IVBASIC POWER STATION REQUIREMENTS AND SITE FEATURES15

VFUEL SOURCE AND TRANSPORTATION TO SITE18

VIPLANT LAYOUT AND CIVIL ENGINEERING ASPECTS19

VIIMAIN PLANT EQUIPMENT AND SYSTEMS24

VIIIINSTRUMENTATION AND CONTROL SYSTEM32

IXWATER SYSTEMS38

XCOAL HANDLING SYSTEM47

XIASH HANDLING SYSTEM51

XIIMISCELLANEOUS SYSTEMS58

XIIIELECTRICAL SYSTEMS60

XIVENVIRONMENTAL PROTECTION AND WASTE MANAGEMENT

79

XVPROJECT SCHEDULE AND IMPLEMENTATION89

XVIPROJECT COST ESTIMATES AND TARIFF 91

LIST OF APPENDICES

APPENDIX NO.TITLE

1.Project Site Details

2.Basic Information for Environmental Appraisal

3.Raw Water Analysis

4.Analysis of Coal

5.Analysis of Fuel Oil

6.Project Cost Estimate

7. Abstract of Project Cost

8.Estimated Cost of Generation

9.Water allocation letter

10Financial Analysis

LIST OF EXHIBITS

EXHIBIT NO.TITLE

1.GRID MAP OF MADHYA PRADESH

2.VICINITY PLAN

3.PLOT PLAN

4.TG BUILDING OPERATING PLAN: AT EL 17.0 M GENERAL ARRANGEMENT

5.TG AND BOILER CROSS SECTION GENERAL ARRANGEMENT

6.HEAT BALANCE DIAGRAM

7.WATER SYSTEM SCHEME AND MATERIAL BALANCE

8.COAL HANDLING SYSTEM FLOW DIAGRAM

9.BOTTOM ASH HANDLING SYSTEM - FLOW DIAGRAM

10.FLY ASH HANDLING SYSTEM - FLOW DIAGRAM

11.KEY ONE LINE DIAGRAM

12.PROJECT MILESTONE SCHEDULE

13.ORGANISATION CHART OPERATION & MAINTENANCE

CHAPTER I

INTRODUCTION

1. Essar Power M.P. Limited (EPMPL) is a wholly owned subsidiary of Essar Power Ltd. It proposes to install a 1,200 MW coal fired pit head based thermal power station near Mahan coal blocks, in Sidhi district of Madhya Pradesh (M.P). It is proposed to supply around 400 MW net power to M.P. State and balance around 700 MW power will be sold to Essar Steel Limited for its steel plant at Hazira in Surat District of Gujrat.EPMPL has been allotted the Mahan Coal Block in Singrauli Coalfields for captive mining. The Mahan Coal Block has reported reserves of 144 million tones.EPMPL would take up extension of power project in second stage as and when opportunity is available in getting nearby mines in Singrauli coalfield allotted. These new coal blocks would be used for the second phase. EPMPL has retained the services of TCE Consulting Engineers Limited (TCE), Bangalore for preparing a Detailed Project Report (DPR) for the proposed 2,000 MW thermal power station.

2. Terms of Reference

3.1 Following are the terms of reference of the DPR :

(a) Power Demand Analysis and justification of project

(b) Study of topographical survey and other data for locating the project considering all pertinent factors including the rehabilitated area

(c) Study of water requirement and finalization of water system.

(d) Study of fuel (coal) requirement, mode of transportation, storage and handling system.

(e) Study of power evacuation and connection with the grid.

(f) Property / Plot plan and preliminary layout of the main plant showing major equipments, coal and ash handling facilities and services corridors etc.

(g) Technical description of all major equipment and systems along with process flow diagrams.

(h) Civil & Structural engineering aspects.

(i) Environmental considerations & adoption of suitable measures as required in accordance with the Pollution Control stipulations.

(j) Project implementation schedule showing key milestone activities.

(k) Estimation of the project cost with broad and detailed breakup under major heads and phased expenditure over the period of project execution.

(l) Computation of the cost of generation at power station bus.

(m) Operation and Maintenance Philosophy including manpower requirement, training & organizational set up.

3.2The scope of services of TCE does not include:

(a) Site survey and soil investigation. (The report would be based on topo-sheet of Survey of India and assumed soil data)

(b) Environmental Impact Assessment (EIA) / Environmental management Plan (EMP) study.

(c) Obtaining clearances and arranging for infrastructure linkages such as fuel linkage, water linkage, land availability, power evacuation etc.

3. The DPR is finalized based on the following :

(a) Report of Central Mine Planning & Design Institute Ltd. (CMPDI) dated March 2004 submitted to Central Electricity Authority (CEA) which identified potential sites for pit-head, coal based thermal power stations in Singrauli Coalfield based on remote sensing data.

(b) Site visit by a team of engineers, discussions held with Madhya Pradesh Electricity Board (MPEB) officials and the information available with TCE.

CHAPTER II

EXECUTIVE SUMMARY

PURPOSE

1. The purpose of this report is to present the techno-economic details of the proposed installation of 1200 MW (Phase I of ultimate capacity of approx. 2000 MW) coal fired thermal power project near Mahan coal blocks near Bandhaura, Khairahi and Karsualal & Nagwa villages, in Singrauli Tehasil of Sidhi District of Madhya Pradesh (M.P).

2. This report highlights the details of the selected site, availability of coal and water, evacuation of power, features of the main plant equipment including raw and cooling water system, coal and ash handling systems, electrical systems, environmental aspects, estimates of project cost, schedule for project implementation and organization structure for operation and maintenance.

SCOPE

3. The scope of this Detailed Project Report (DPR) covers the following:

(a) Need for installation of two phases, totaling to ultimate capacity of approximately 2000 MW, coal fired thermal power station

(b) Study of the selected site considering topography, soil conditions, accessibility by road and rail, availability of water for condenser cooling and other requirements, power evacuation plans, transport of fuel required for the plant from the nearby mine, space availability for ash disposal and general environmental aspects

(c) Preparation of plant layout keeping in view the ultimate capacity of 2000 MW power plant.(d) Details of the major aspects of the proposed plant, general design philosophy and salient technical specifications of the following major equipment/systems for the proposed first phase of 1,050 MW unit installation in addition to power plant configuration :

(i) Steam-generator and auxiliary systems

(ii) Steam turbine-generator and auxiliary systems

(iii) Water systems

(iv) Coal handling system

(v) Ash handling system including ash disposal system and a brief outline of possible schemes for utilization of ash generated in the plant

(vi) Fuel oil supply system (vii) Other mechanical balance of plant systems

(viii) Electrical systems and power evacuation system

(ix) Instrumentation and control systems

(x) Civil, structural and architectural aspects

(e) Environmental aspects

(f) Preparation of project implementation schedule

(g) Project cost estimates and financial analysis.

PROJECT FEATURES

4. Land

(a) Land required for setting up two phases, totaling to ultimate capacity of approximately 2000 MW, coal based power station is of the order of 1790 acres (725 hectares) for both the phases including power plant and its all auxiliary systems, ash disposal area and colony.

(b) Land close to Mahan coal blocks, about 4 km from the mine has been identified for power station. Adequate area for setting up of Phase I and Phase II is available. Land for around 725 Ha has been identified in four villages i.e. Khairahi, Kharsualal, Bandhara and Nagwa. The area of the villages have been identified to accommodate main plant, ash pond area, Local township/colony in such a manner that no. of PAF is kept at bare minimum.(c) Primarily the land is consisting of waste land with/without scrubs (about 50%) and agricultural land (about 50%). Settlement of around 250-300 households is expected to require resettlement and M/s. EPOL has already initiated a detailed R&R study, being conducted by TCE to assess and implement the R&R plan. Discussions are already going on with District Collector regarding R&R policy. (d) Two railway stations are situated near the proposed site: (i) Singrauli: on the Katni- Chopan Section which is about 35 km away and (ii) Shaktinagar: in U.P at a distance of 35 km. The nearest air port is varanasi (280 km).

(e) The site is located west of Govind Vallabh Pant Sagar (GVPS) at about a distance of 37 km.

5. Water

The source of water required for the proposed thermal power plant is Govind Vallabh Pant Sagar (GVPS) reservoir, which is estimated to be at a distance of 37 km from the site. Government of M.P was approached for confirming availability and allocation of 71.45 million cu. m (80 Cusecs/0.058 MAF) water which would be sufficient for the ultimate capacity of 2,000 MW power plant. On the basis of present consumption of 0.227 MAF out of M.P.s share of 0.78 MAF from the reservoir basin, the Govt. of M.P has allocated the said quantity of water from the reservoir. 6. CoalPower plant would get coal from Mahan coalfield which is located in main Singrauli coalfield basin. Mahan Coal block has been allocated jointly to Essar Power & Hindalco Industries by Ministry of Coal, GOI. Mahan coal mine is situated at about 4 km (North-West)from the proposed plant site.

The coal bearing area of the Mahan block lies in the main basin of Singrauli Coalfield and has a reserve of 144 Million Tonnes. The area of the coal block is about 9.2 sq. kms. Total average coal thickness is about 11 m. Depth range of coal seam is upto 150 m.7. Power Evacuation

The Power generated from the proposed station will be stepped up to 400KV and power will be evacuated to the 400KV Substation at Sipat-Pooling Point (around 215 Km approx. away). In addition to that there will be LILO with two nos. SC 400 KV line from Vindhyachala-Korba at Mahan. Thus the project will have connectivity with WR pooling point at Sipat, Vindhyachal STPS and Korba STPS at 400 KV. In addition to that the necessary augmentation and strengthening of the PGCIL grid for further power evacuation will be made after due discussion with the WR constituents/CEA and PGCIL. 8. Power Utilization and Sale of Power

It is planned that around 400 MW power will be supplied to the state of M.P in line with the MoU signed with them and rest 700 MW power will be used for Essar Steel Ltd at Hazira in Surat District of Gujrat.9. Main Plant Equipment

9.1 Based on the analysis, it is recommended to install two (2) units each of approximately 600 MW capacity in each phase. Other configuration options would be studied during detailed Engg stage.

9.2 The steam generators would be 100% coal fired and would be rated to generate about 2028 t / hr of superheated steam at 179 ata pressure and 540(C temperature when supplied with feed water at a temperature of 252o C at the economizer inlet. The reheat steam temperature would also be 540(C.

9.3 The steam turbine generator (STG) would be rated for 600 MW maximum continuous output at the generator terminals, with throttle steam conditions of 170 bar and 537oC steam temperature and 0.1 bar (a) back pressure.

9.4 The steam turbine would be a reheat extraction and condensing type turbine. The STG output, at valve wide open (VWO) condition could be 630 MW. Steam turbine would be a two / three cylinder reheat, extraction and condensing turbine. The parameters indicated above are preliminary and subject to confirmation by the selected main equipment suppliers.

10. Coal Handling System

It is envisaged that run off mine coal for this project would be received from Mahan coal fields belonging to Essars captive coal mines. The annual requirement of coal for the power plant would be about 5.0 million tonnes considering a plant load factor of 80% and coal GCV of 4,100 k Cal / kg. However it may be noted here for the purpose of designing the boiler and all other auxiliaries a GCV of 3800 Kcal/kg is considered. The coal handling system envisaged would be capable of handling coal at the rate of 1,600 tonnes / hour and would consist of two streams of conveyors, one operating and the second one being standby.

11. Ash Handling System

11.1 The bottom ash handling system proposed envisages evacuation and transportation to a storage silo in wet form and from thereon for onward disposal by jet pumps to the ash disposal area.

11.2 Fly ash from the respective hoppers of ESP, Eco/AH of each boiler will be evacuated in dry form through dense phase pressurized pneumatic system to the fly ash silos for storage and subsequent evacuation. Fly ash from silo will be sent to cement/brick plant manufacturers to the maximum extent possible and the bottom ash will be utilised for development of low lying area. The rest of fly ash plus the bottom ash will be disposed off in slurry form to the ash pond to be located nearby. There would be water recovery plant at ash pond through a clarifier/pump house to send back the clear water for re-use. The make-up water for ash slurry disposal system will be met from cooling water blow down system. Also the ash pond will be provided with a HDPE Protective layer if required to avoid any contamination of ash water with ground water.12. Condenser Cooling and Make-up Water

12.1 The source of consumptive water for the thermal power plant would be Govind Vallabh Pant Sagar (GVPS) reservoir, which is at about a distance of 37 km from the power plant. The total requirement of raw water make-up is of the order of 48 cusecs for the 1,200 MW power plant capacity and 80 cusecs (42 MGD) for 2,000 MW capacity. Raw water is proposed to be pumped from the river water pump house to a raw water pond (buffer to cater for 2 days storage).

12.2 For the condenser cooling, closed circuit re-circulation system with clarified water make-up using natural draft cooling towers has been proposed. The make up water for the condenser cooling would be drawn from the clarifier by gravity and gets discharged into the common CW forebay. From the CW pump house the cooling water would be pumped to the condenser through individual MS conduits. The discharge would be led to the cooling tower through similar MS conduits.

12.3 Raw water required for other services viz. DM plant, fire protection system, cooling water make up for air-conditioning & ventilation system and plant potable water system, service water, auxiliary cooling (bearing cooling) etc. would be pumped from a common clarified water tank.

12.4 Feed cycle makeup and cooling water for steam generator and turbine generator auxiliaries would be met from the DM plant output.

13. Environmental Aspects

13.1 The power plant is proposed to use coal brought from Mahan captive mine blocks located in Singrauli Coal Fields having low Sulphur content. One (1) twin-flue 275 m high RCC chimneys (stacks) is proposed to be provided common for two steam generator units to meet the requirements of the environmental regulations. The steam generators would be provided with low NOx burners and hence the emission of oxides of Nitrogen from the steam generator would be minimum.

13.2 The steam generators would be provided with electrostatic precipitators to limit the particulate matter in the flue gas to 100 mg / N cu m as per the Good Utility Practices which is better than the current pollution control norms.

13.3 Adequate provisions are proposed for neutralizing the effluents from the water treatment plant. Effluents from the entire power plant are proposed to be treated and reused in the power plant to minimize the make-up water requirement.

14. Project Cost and Tariff

14.1 The estimated capital cost of the proposed project in stage I of 1200 MW capacity based on prevailing rates in Mar 2007 is Rs. 4860 crores including interest during construction (IDC) and financial charges. The above cost is based on in-house data and budgetary costs. The cost per MW of installed capacity works out to Rs. 4.05 crores / MW.

14.2 The cost of generation at 80 % PLF works out to Rs. 2.16 per kWh including return on equity. The levellised tariff works out to Rs. 1.82 per kWh for the net energy from the 1st stage of the proposed super thermal power station of 1200 MW capacity.

15. Project Schedule and Implementation

15.1 The Commercial Operation Date (COD) for the 1st stage of the power station of 1200 MW capacity will be as below:

First unit of 600 MW capacity (Unit # 1) is envisaged in 36 months reckoned from the date of financial closure followed by the other unit within three months. Financial closure is anticipated to be achieved by 30th June 07.15.2 The project is proposed to be executed through a number of separate package contracts finalized through competitive bidding.

15.3 The time period between the Phase I and Phase II would be about 2 Years, subject to allotment of new coal blocks.CONCLUSIONS

1. Based on demand-supply gap in India, it is concluded that setting up of a 2,000 MW capacity coal fired power station in two stages in Sidhi district of M.P state is viable from the technical and economical points of view.

2. The proposed power plant has all the basic requirements essential for a thermal power plant viz. land, water, fuel (coal) and power evacuation facilities.

RECOMMENDATIONS

3. To ensure timely completion of the proposed project, it is recommended that early action on the following activities may be initiated by EPMPL and arrange for the following expeditiously to realize the advantage of first entrant in the State of M.P in the recent past :

(a) To conduct detailed topographic survey of the identified land and the land in the vicinity so as to firm up actual coordinates and extent of land to initiate acquisition.

(b) To carryout detailed soil and geo-technical investigations to ascertain load bearing capacity and to conclude type of foundations viz. open type foundations or pile foundations.

(c) Discussion with MP govt, other beneficiary states/users, PGCIL and other state utilities for power purchase agreement and wheeling of power(d) Initiate action to obtain necessary clearances for raw water intake pipeline corridor and coal conveyor corridor from mines.

(e) Approval of Civil Aviation Authority for installing 275 m high chimneys.

(f) Initiate discussions with prospective Indian Financial Institutions, Foreign Financial Institutions, external commercial borrowing agencies, Indian commercial banks and reputed main plant equipment suppliers

(g) Appointment of Project Consultant for carrying out detail engineering.

CHAPTER III

NEED AND JUSTIFICATION FOR THE PROJECT

1. Essar Steel Limited is having an integrated Steel Plant of 4.6 mtpa capacity at Hazira in Surat Dist of Gujarat. Presently its demand is being met from the 515 MW Combined Cycle Power Plant of Essar Power Limited located adjacent to it. In addition to that demand also is being met from a 505 MW plant of Bhander Power Limited (a Subsidiary of Essar Power Limited) which is under construction and located adjacent to the 515 MW plant. Out of 500 MW capacity, around 355 MW is already commissioned and balance 150 MW is scheduled to be commissioned in next few months time.

2. Essar Steel (Hazira) Limited is a subsidiary of Essar Steel Limited and is in advanced stage of putting up a 3.9 mtpa Corex gas fired steel plant at Hazira.3. It is a well known fact that steel plant is highly energy intensive and needs continuous uninterrupted power. The cost of power is one of the major cost contributor and hence the availability of low cost power becomes the key for production of steel.4. In view of present scarcity and high cost of natural gas and liquid fuel (Naptha) Essar Steel Limited shall be supplied around 400 MW power from Proposed Mahan pit head power project, while transmitting the same through EHV lines of 400/765 KV.

5. Further Essar Steel (Hazira) Limited also intends to source power to the rune of 320 MW from Mahan pit head STPP for its new steel plant of 3.9 mtpa capacity.

6. EPMPL has signed a MoU with the Govt of M.P for setting-up the Mahan Power project. As per the terms of agreement EPMPL has agreed to supply 7.5% of net generated power on real time basis at variable cost. In addition to that the authorised agency of Govt of M.P reserves the first right of refusal for 30% power from Mahan STPP.

7. EPMPL has already qualified for bidding for power procurement by M.P SEB through which the tariff will be finalised and subsequent to that the PPA will be signed for 25 years for supply of the power to the state.

8. The State of Madhya Pradesh is part of the Western Region comprising the states of Goa, Gujarat, Maharastra, Chattisgarh, Daman & Diu etc. The installed / available generation capacity in Madhya Pradesh is 2991 MW, as on Dec2005.

9. The Ministry of Power (MoP) of Govt. of India has projected the following peak demand and energy requirements at National level and in particular western region as follows :

Table-III.1ProjectionEnergy Requirement in MUPeak Load ( MW)

2006-072011-122006-072011-12

All IndiaA719,097

975,222115,705157,107

B669,034898,135106,465149,365

Western RegionA224,927299,07535,22346, 825

B232,742321,57835,96850,747

C349, 17953,377

A- Projections AS per 16th EPS B- Revised Projections based on actual figures of 2004-05 and actual growth measured between 1992-2005, plus anticipated demand from additional Rural Electrification.

C- Modified demand projections for the purpose of planning future capacity addition by readjusting for unreported Power cuts/disruptions on regional basis keeping All India Projections as per 16th EPS.

Note: 1. C for All India level is same as figures for A.

2. Source National Electricity Plan. 10. The installed / available generating capacity of the existing power stations, projects under execution, projects under planning as well as the share from the Central Sector projects for the period 2006-07 to 2011-12 for M.P. State are shown in Table - III.1. The installed capacity of the existing plants, the data on projects under execution and planning furnished in this Table is based on the information obtained from Madhya Pradesh Electricity Board (MPEB)

Table-III.2

List of Projects existing, Under Implementation / Planning

Sl. No.ProjectMWExpected year of availability and MW

2006-20072007- 20082008-20092009-20102010-20112011-2012

I.i) State owned (Amarkantak extn.)

ii) Lanco Amarkantaka2,148210-

300---

iii) Birsinghpur extn.500

iv) Hydel ( Ban sagar)-IV84320

v) Medhikheda40

vi) Indira Sagar1000------

vii) Sardar Sarovar743119

viii) Omkareshwar (8X65)520

IICentral sector

Share1,733273+

500180360+166166166500

IIINon conventional

Nil-------

IVTotal of additional planned capacity -1452910826166166500

VExisting plants, non conventional including share from central projects 6,4677919882996559821998710487

VITotal expected capacity by the year wise in MW6,4677919882996559821998710487

DEMAND FOR ELECTRICAL POWER AND ENERGY

11. The demand for electrical energy has been steadily increasing in the State of Madhya Pradesh due to rapid industrialization and agricultural growth. The existing peak power demand in the year 2005-06 was 8 GW, which is 68.4% of the projected peak load for the same year. The peak load and the expected energy requirement as projected in the Sixteenth Electric Power Survey of India for the State of Madhya Pradesh for the period 2005-06 to 2011-12 is shown in Table III.2 (X plan-2006-07, XI plan-2011-12).

AVAILABILITY OF POWER

12. The Power Survey of India recognized that while computing the available peak power from the installed capacity, the following factors need to be considered:

(a) Planned outage due to maintenance

(b) Forced outage

(c) Spinning reserve

(d) Auxiliary power consumption

(e) Other factors relevant to the aspect of peak power availability.

Considering the above-mentioned factors, the peak power available is estimated in Table III.2. For energy availability, 70% load factor is considered for Thermal plants. The energy availability is taken as per the data collected from MPEB.

Table-III.2

Peak Power Demand Requirements

2005062006072007-082008-092009-102010-112011-12

Total Installed capacityMW64677919882996559821998710487

Peak Demand Forecast

(16th EPS)* MW8186866191559677102301081411431

Average Demand forecast (16th EPS) MW5649597763186679706074637889

Our conservative peak demand forecastMW5243555858916244661970167437

Our conservative avg demand forecastMW 4294455248255114542157466091

Estimated peak generation availableMW3835475553015797589759976297

Estimated avg generation available MW3196396244184831491449985248

Peak demand shortfallMW140880359044772210191140

Avg demand shortfallMW1098589407283507749843

*As per Sixteenth Annual Power Survey of India

NEED FOR THE POWER PROJECT

13. As may be noted from the above Table III.2, there would be deficit in generation capacity. The estimated deficit by the 11th Five year plan are of the order of 1 GW for generation capacity.

14. Further, the availability of power depends on the number of plants under execution / planning as indicated in Table III.1 getting commissioned in time. Any delay in the implementation of power projects, due to reasons such as lack of clearances, financial constraints, etc. would result in much larger deficit in subsequent years. Considering this scenario, there would be a large deficit in peak availability and energy availability.

15. Considering the above scenario of power requirement by the group companies and the persisting power shortage in Western region, Mahan Super Thermal Power Project is well justified. CHAPTER IV

BASIC POWER STATION REQUIREMENTS AND SITE FEATURES

BASIC STATION REQUIREMENTS

1. The estimated requirements of land, fuel and water for the proposed power plant installation of two phases, totaling to ultimate capacity of 2000 MW, coal fired thermal power station are presented in Table - IV.1below :

TABLE - IV.1

Estimated Requirements of Land, Fuel and Water for a 2000 MW Coal Fired Thermal Power Station

Land for power plant with the facility for ultimate expansion to 2,000 MW427.8Ha (1057 acres) for the power plant including main plant etc. 267.6 Ha (661 acres) for ash disposal area and 30.2 Ha (75 acres) for colony.

Annual coal requirement

(With annual load factor of 80%) for 1st phase of 1200 MW)5.0 million tones

Total raw water requirement

48 Cusec for 1st stage of 1200 MW and 80 cusecs (or 196,000 cu.m / day) for ultimate capacity of 2000 MW capacity

SITE FEATURES

2. Site Location

The proposed site is located near Mahan coal blocks near Bandhaura, Khairahi, Karsualal and Nagwa villages, in Singrauli tehasil of Sidhi District of Madhya Pradesh (M.P). The latitude and longitudes of the main power project location are 240 0 0 / 820 25 0. The land identified for the project is shown in Exhibit-2.

3. Basis of site selection

Central Mine Planning & Design Institute Ltd. (CMPDI), in its Report dated March 2004 submitted to Central Electricity Authority (CEA) had identified potential sites for pit-head, coal based thermal power stations near Singrauli coal fields based on remote sensing data. Out of these, EPMPL preferred the Site which is located near Mahan coal blocks near Bandhaura, Khairahi and Karsua village, Sidhi district in M.P from various technical considerations. TCE also studied the Report and concurred with EPMPLs choice.

4. This Site is about 37 km away from Govind Vallabh Pant Sagar reservoir from where consumptive water is proposed to be drawn for the proposed power project.

5. Primarily, the identified area consists of waste land with / without scrubs (about 50%) and agricultural land (about 50%).The plant will be located in such a manner to minimize the resettlement of the villagers.

6. The layout of the power station shall be finalized duly considering the exact coordinates of the power lines which is possible only after a detailed topographical survey.

7. Characteristics of Location and Land

Terrain for the proposed main plant is almost flat with elevations ranging around 338 M above MSL in the main plant area (Kharahi/Kharsuaal). In the absence of soil characteristics, it is assumed that the foundations of the structures do not require piles and good soil bearing capacity is expected to be available even at lower depths. The water table is also assumed to be relatively high (about 4-5 M below ground level) in this area. However, all these assumptions are to be validated after suitable surveys / studies / investigations.

8. Resettlement and Rehabilitation (R&R)

Settlement of around 771 families is expected as per the R&R study carried out. The R&R plan will be in line with the policies of the state government.9. AVAILABILITY OF WATER

The source of water required for the proposed thermal power plant is Govind Vallabh Pant Sagar (GVPS) reservoir, which is estimated to be at a distance of 37 km from the site.

10. COAL SOURCE AND TRANSPORTATION

Power plant would get coal from Mahan coalfield which is located in main Singrauli main basin. Mahan Coal block has been allocated jointly to Essar Power & Hindalco Industries by Ministry of Coal , GOI. Low grade coal from Mahan coal mines situated at about 4 km is proposed to be used for this project.11. POWER EVACUATION

EPMPL initiated a study for augmenting/strengthening the PGCIL grid including the connectivity of the proposed station with the nearest 400KV substation. As per study a double circuit line at 400 KV will have to be laid to the WR Pooling point at Sipat over 215 Km distance. In addition to that a LILO is proposed with two nos. single circuit 400 KV line connecting Vindhyachal STPS Korba STPS at Mahan 400 KV switchyard. Further to that a 400 KV double circuit line will be laid from Gandhar to a new 400 KV switchyard at Hazira. The long term open access application is made to PGCIL for finalizing these schemes in addition to the augmentation of the PGCIL network. The same will be finalised with due discussion and consultation with PGCIL/CEA and other WR constituent members. 12. ENVIRONMENTAL ASPECTS

There is no metropolitan city or eco-sensitive spots including national parks, wild life sanctuary, biosphere reserve, historical and cultural sites present in the vicinity of the proposed site as per Ministry of Environment and Forests (MoEF) guidelines. Further, super thermal power plants existing in the nearby vicinity viz. Vindhyanchal STPS, Singrauli STPS, Rihand STPS and Anpara STPS. are more than 25Km away from the proposed station.13. Also, all necessary pollution control measures are being proposed for the power plant. Thus, the site has all the infrastructural requirements for the proposed power plant expansion. It is therefore, considered that this site is suitable for the installation of the proposed power plant expansion units.

CHAPTER V

FUEL SOURCE AND TRANSPORTATION TO SITE

TYPE OF FUEL 1. The steam generators would be designed primarily for coal firing. Light Diesel oil would be used for start-up and HFO for flame stabilisation at low loads.

SOURCE OF FUEL AND QUALITY2. Coal for the project would be indigenous, supplied from the Mahan coal fields belonging to Essars captive coal mines located in main Singrauli Coal Fields in the State of M.P. The expected Run-off-Mine (ROM) coal analysis is expected to be as furnished in Appendix - 4. ROM coal is planned to be fired in boilers directly which would be having a maximum of 40% ash content and a gross calorific value (GCV) of about 4,100 k Cal / kg.

3. The secondary fuel would be HFO as per IS:1593. Fuel oil for the power plant would be made available from Essar / HPCL / BPCL / IOC.

ANNUAL COAL REQUIREMENT4. The annual coal consumption for the proposed first phase of power plant is estimated as 5.0 million tonnes duly considering average GCV value of ROM coal as 4,100 k Cal / kg and annual plant load factor (PLF) of 80%. However as for as plant design is concerned, a calorific value of 3800 kcal/kg is considered.

MODE OF TRANSPORT OF COAL TO SITE

5. Coal from the mines is envisaged to be transported to power plant by conveyors. 6. The coal handling system envisaged would be capable of handling coal at the rate of 1,600 tonnes / hour for the 1st stage of 1200 MW power plant and would consist of two streams of conveyors, one operating and one being standby. FUEL OIL REQUIREMENT AND MODE OF TRANSPORT OF FUEL OIL TO SITE

7. The fuel oil system would be designed for the use of Light Diesel Oil (LDO) for start up and HFO for flame stabilization purposes.The HFO/LDO requirement to the tune of 1800KL/month for 1st stage of 2000MW Project.8. Oil is envisaged to be supplied from nearest terminal by using road tankers to the site. 7 days of oil storage is considered adequate during trial operation. Hence, a total HFO storage capacity of 5000 m3 has been envisaged.CHAPTER VI

PLANT LAYOUT AND CIVIL ENGINEERING ASPECTS

PLANT LAYOUT

1. The layout of the main plant along with all the auxiliary systems has been shown in Plot Plan (Exhibit - 3). In laying out various facilities consideration has been given to the following general principles :

(a) Least disturbance to existing habitation and vegetation, if any.

(b) Flexibility to have future expansion units with particular reference to the switch yard

(c) Predominant wind directions as gathered from the wind rose to minimize pollution, fire risk, etc.

(d) Power evacuation corridor for connection to state grid

(e) Raw water intake facilities

(f) Approach road to the power plant from the main highway

(g) Availability of adequate space for fabrication / construction equipment.

(h) Availability of adequate space for labour colony during construction stage.

2. All facilities of the plant are laid out in close proximity to each other to the extent practicable so as to minimise the extent of land required. The layout also facilitates communication of men and movement of materials between the various facilities both during initial construction and also during subsequent operation and maintenance.

3. Fuel oil would be received by road tankers.

CIVIL ENGINEERING ASPECTS

Site Topography And Grade Level4. Site terrain is almost flat without significant undulations and the elevations is around 337 M above MSL. The main plant, auxiliary buildings and coal stockyard etc. would be located at suitably higher level of than the general grade level.

Station Building : General Arrangement5. General arrangement plan of the station building is shown in Exhibit 4 and sectional view is indicated in Exhibit 5. The steam turbine generator and auxiliary equipment would be located in the AB bay of the building having 34.0 span. Each unit is accommodated in a length of 10.5 x 9 bays. Total length of station building for both the units would be 210 m which includes two unloading / maintenance bays each of 10.5 m wide at the end of the station building. The heaters are accommodated in the BC bay ( Heater bay) having a span of 10.0 m. The control room / electrical building is located on the side ot the station building to accommodate switch gear, electronic panels and control room in a space of 63.0 m x 21.0 m.

6. The turbine - generator bay would be serviced by three floors - ground floor at 0.0 M level, mezzanine floor at 8.5 M level and operating floor at 17 M level. Localised O&M platforms at required levels would be provided. The deaerator would be located at EL 31.75 M in the BC bay (heater bay). Road access would be provided to the unloading and maintenance bays for unloading TG components and auxiliary equipment.

7. The superstructure would be of structural steel framing with RCC floor slabs. The roof of the TG bay would consist of pre-cast concrete panels supported on steel trusses. The turbine generator pedestal would be reinforced concrete and would be isolated from the building foundations and super structure. All structures would be designed to cater to applicable wind/seismic forces in the area as per relevant Indian Standards.

Steam Generator Area and Mill Bay8. The mill bay would be of structural steel-framed construction, supporting the steel bunkers. The 12 m wide bay would have blower room at ground level and floors for the feeders and for the bunker feeding conveyors provided with trippers. The bunker bay would be located at the front side between the furnace in the steam generator area and the T-G building. Concrete paving would be provided in the steam generator area with necessary drains and trenches. Pipes and cables in this area would, in general, be routed on overhead pipe / cable racks.

9. The general arrangement plan of the steam generator cross section is shown in Exhibit 5.

Chimney10. Twin-flue chimney with common wind shield for the two units has been envisaged for the proposed thermal power plant. The total height of reinforced concrete chimney is 275 m with 6.5m diameter at exit. This would meet the requirement of Indian Emission Regulation. The chimney windshield shall be of RCC slipform construction.Miscellaneous Buildings11. Table - VI.1 below indicates list of major buildings / structures planned in the power plant and type of construction :

Table -VI.1

Major Buildings / StructuresSl. No.Building / StructureRemarks / Type of Construction

1.ESP control roomGround plus one floor; common for two units. Structural steel construction with brick walls. Floors and roof would be of RCC.

2.Air washer roomsTwo per unit; Each having ground plus one floor. Structural steel construction with brick walls. Floors and roof would be of RCC.

3.Ware house and WorkshopStructural steel columns with bricks for side cladding. Pre-coated galvalume sheet supported on structural steel would be provided for roof.

4.D.G houseStructural steel construction with pre-coated galvalume sheet for roof. Sides are kept open.

5.Hydrogen cylinder shedStructural steel construction with pre-coated galvalume sheet for roof with 1.8 m high brick dwarf walls for the sides.

6.CW pump house & MCC room Structural steel construction with brick walls

7.Clarified water pump houseStructural steel construction with brick walls.

8.D.M PlantStructural steel columns with pre-coated galvalume sheets for roof. Roof is supported on structural steel trusses. Sides are kept open.

9.Coal handling switch gear cum control roomStructural steel construction with brick walls

10.Switch yard control roomStructural steel construction with brick walls

11.DM plant control room cum switch gear roomConcrete construction with brick walls

12.Ash handling compressor room + MCC roomCompressors would be provided with metallic containers and covered shed would be provided for protection.

13.Admin BuildingConcrete construction with brick walls

14.Canteen BuildingConcrete construction with brick walls

15.Service BuildingStructural steel construction with brick walls. Floors and roof would be of RCC.

16.Fire Station BuildingStructural steel construction with pre-coated galvalume sheet for roof. Sides are kept open. Fire office space would be of concrete construction with Brick walls

17.Car / Scooter parkingStructural steel construction with pre-coated galvalume sheet for roof. Sides are kept open.

Soil Profile and Foundations

12. Details would be furnished after the detailed geo-technical investigation of the proposed area is carried out. However the net safe bearing capacity of 25 t/m2 at 4.0 m below the existing ground level is considered for cost estimation purposes.

Machine Foundations

13. All equipment would be supported on conventional block / framed type RC foundations and would be separated from the building foundations and superstructure. All variable speed machines would be supported on vibration isolation system with springs and viscous dampers.

Roads, Drains & Boundary Wall

14. The roads would initially be of water-bound macadam type with shoulders on either side of carriage width. After major construction activities are completed, these would be surfaced with bituminous carpet. All major roads would be 7.0 m wide and other approach roads would be 4.0 m wide. Storm water drains would be provided on either side of the roads. The storm water drains would be of RCC construction. The storm water drains would be connected to the nearest water body or would be treated suitably and reused for gardening and other purposes. The power plant boundary wall of 3.0 m height with anti-climbing device would be constructed from locally available stones.Design Basis

15. Dead and live loads would be considered as per relevant IS codes and standard engineering practices. The basic wind speed of 50 m / s is considered for design of buildings / structures as per IS : 875 : Part III. The power plant is located in Seismic Zone III as per IS : 1893 and seismic forces would be considered accordingly for the structures / buildings. All designs would be carried out in SI units and would be as per relevant IS codes.

Sewage Disposal

16. Sewage from various buildings would be lead to septic tanks located close to the buildings by means of CI pipes laid underground. The overflow from septic tanks would be led to the dispersion trenches or soak pits.

Landscaping

17. The various services / utility areas within the plant would be suitably graded to different elevations. Natural features of the plant site would be retained as far as possible to integrate with the buildings to form a harmonious / pleasant environment. Areas in front of various buildings and the entrance of power plant would be landscaped with ground cover, plants, trees based on factors like climate, adaptability etc. The green belt would consist of native perennial green and fast growing trees. Trees would also be planted around the coal stock pile area and ash disposal area to minimise the dust pollution.

CHAPTER VII

MAIN PLANT EQUIPMENT AND SYSTEMSPLANT CAPACITY AND SELECTION OF UNIT(S) SIZES

Plant Capacity

1. 1,200 MW capacity coal based thermal power plant has been proposed at selected site to be implemented in first phase. Accordingly, all the plant facilities / equipment / systems would be designed and selected for a plant capacity of 1,200 MW only.

Selection Of Unit Sizes

2. The following alternative plant configurations are feasible for the proposed 1,200 MW thermal power plant in 1st stage :

(a) 4 x 300 MW units

(b) 2 x 500 MW units plus one unit of 210 MW.(c) 2 X 600 MW Units

3. A number of 500 MW units are already operating in the country since 1979, with first 500 MW unit installation at Trombay Thermal Power Station, Tata Electric Companies, Mumbai, followed many installations in NTPCs super thermal power stations at Ramagundam, Korba, Singrauli, Talcher and MSEBs Chandrapur and UPSEBs Anpara Thermal Power Station. So far the performance of these 500 MW units have been quite satisfactory.

4. Similarly, the first set of 2 x 250 MW units were commissioned in 1995 at Dahanu thermal power station followed by other units at Kothagudam and Suratgargh. These units have also demonstrated proven performances over their respective operating periods.

5. Many no. of 600/300 MW units are running in China and their performance also have been reported to be good.

Merits of 1 x 500 (600) MW Unit Vs 2 x 250 (300) MW Units Installation

6. From the Tables VII.1 and VII.2, it may be concluded that 1 x 500 MW unit has the following merits over 2 x 250 MW units configuration :

6.1 Heat rate of 500 MW unit is lower than 250 MW unit by 24.78 k Cal / kWh resulting in annual fuel saving of about 26,819 tonnes and hence reduction in annual fuel charges by Rs. 2.68 crores.

6.2. Station building volume for 500 MW unit is less than 2 x 250 MW units requirement by 24,000 M3 resulting in substantial saving in civil works which is estimated at Rs.5.28 crores.

6.3. 1 x 500 MW unit configuration being a single unit installation, the O & M staff requirement in the main plant area practically reduces one half of 2 x 250 MW units configuration. Further inventory of spares would also reduce substantially as the number of equipment / components in 1 x 500 MW unit is about one half of 2 x 250 MW units. Hence, there would be substantial reduction in O & M costs.

6.4. Overall space requirement for the main plant area i.e. Steam turbine, Steam generator and switchyard area in case of 1 x 500 MW unit is 80,000 M2 as against 90,000 M2 for 2 x 250 MW units.

6.5. From the thermal power plant performance data published by CEA in the past, the availability and plant utilisation factor of 500 MW units (86.61 & 78.14) is substantially higher than 200 / 250 MW sets (81.79 & 72.94) respectively.

6.6. The comparison between 1 X 600 MW with 2 X 300 MW units are in similar with 1 X 500 MW with 2 X 250 MW.

Demerits of 1 x 500 (600) MW Unit Vs. 2 x 250 (300) MW Units Installation7. The only demerit of 1 x 500 MW unit installation vs 2 x 250 MW units is that in the event of failure of the unit, there will be total loss of generation of 500MW as against only 250 MW generation in case of 2 x 250 MW installations.. The comparison between 1 X 600 MW with 2 X 300 MW units are in similar with 1 X 500 MW with 2 X 250 MW.

Recommendation8. In view of the above discussions and duly considering the advantages such as lesser O&M staff, lesser space, better heat rate, Installation of 500 MW/ 600 MW units for the 1st stage are recommended. However configuration would be ultimately left for EPC contractor who would quote least capital cost and running cost including heat rate. The selection would include 2 x 500 MW, 2 x 600 MW and 2 x 660 MW. Choice of subcritical or supercritical parameters would be left to EPC bidders.9. The forthcoming paras of this Chapter briefly describe the salient features of main plant equipment viz. Steam generator, Steam turbine generator and their auxiliaries. It may be appreciated of the fact that 600 MW unit size is considered as bench mark capacity. The actual gross capacity may be in 500, 600, 660 MW sets depending upon the suppliers standard rating. Such a flexible gross capacity would be specified in the RFP as and when issued to take the full advantage of manufacturers standard range of main plant equipment.

STEAM GENERATOR AND ACCESSORIES

10. The steam generator (SG) would be designed for firing 100% coal and would be with assisted circulation and drum type. The SG would be of two pass design, radiant, single reheat, balanced draft, semi-outdoor type, rated to deliver 2028 t / hr of superheated steam at 179 ata, 540(C when supplied with feed water at a temperature of 252(C at the economiser inlet. The reheat steam temperature would also be 540(C.

11. The steam generator would be provided with coal mills on either side of the furnace, along with individual raw coal gravimetric feeders and coal bunkers. Sampling arrangement at mill outlet would be provided for purpose of establishing the average gross calorific value of coal as well as coal fineness. The coal mills would be provided with steam blanketing system for the purpose of fire protection. The SG would be designed to handle and burn HFO as secondary fuel up to 22.5 % MCR (maximum continuous rating) capacity and flame stabilisation during low-load operation. For unit light up and warm up purposes LDO would be used with air atomization. The required fuel oil pressurizing units and fuel oil heating equipment would be provided. High-energy electric arc ignitors would be provided to ignite the fuel oil guns.

12. The steam generator would consist of water cooled furnace, radiant and convection super-heaters, re-heaters, economizer, regenerative air heaters, steam coil pre-heaters, etc. Soot blowers would be provided at strategic locations and would be designed for sequential fully automatic operation from the unit control room.13. The draft plant would comprise of primary air fans, forced draft fans, and induced draft fans. Electrostatic precipitator (ESP) and fly ash hoppers would be provided for the collection of fly ash. The ESP would be designed with one field standby for design coal firing and with no field standby for worst coal firing, to achieve an outlet dust concentration of 100 mg / Nm (Max) as stipulated by State / Central Pollution Control Board.

STEAM TURBINE GENERATOR AND ACCESSORIES

14. The steam turbine generators (STG) would be rated for 600 MW maximum continuous output at the generator terminals, with throttle steam conditions of 170 bar (a) and 5370 C steam temperature and 0.1 bar (a) back pressure. The steam turbine would be a reheat extraction condensing turbine. The STG output, at valve wide-open (VWO) condition could be 630 MW. Steam turbine would be a two/three/ cylinder reheat, extraction and condensing turbine.15. The turbine-generator would be complete with all accessories such as protection system, lube and control oil systems, seal oil system, jacking oil system, seal steam system, turbine drain system, 60% MCR HP / LP bypass system, electro-hydraulic control system, automatic turbine run-up system, on-line automatic turbine test system and turbine supervisory instrumentation. The turbine-generator would also have all necessary indicating and control devices to permit the unit to be placed on turning gear, rolled, accelerated and synchronised automatically from the control room. Other accessories of the turbine-generator would include an oil purification unit with transfer pumps and clean and dirty oil storage tanks of adequate capacity.

16. Plant Cycle

16.1. The preliminary heat balance diagrams at (100% MCR with 0% make-up) for the turbine cycle system are furnished in Exhibit - 6.

16.2. The condensing plant would comprise a surface type condenser with two pass design of single shell construction. The condenser would be suitable for use of river /raw water for condenser cooling. The condenser would have stainless steel tubes rolled in to carbon steel tube sheets. 2 x 100% capacity vacuum pumps would be provided to create vacuum in the condenser during start-up and to remove the non-condensable gases liberated during normal operation.

16.3. The regenerative cycle would consist of three low-pressure heaters, a variable pressure de-aerator, two high pressure heaters, one drain cooler and one gland steam condenser. The heat balance diagrams of turbine cycle are presented in Exhibit - 6.

16.4. Under normal operating conditions, drains from the high-pressure heater would be cascaded to the next lower pressure heater and finally to the de-aerator. Drains from low pressure heaters would be cascaded successively to the next lower pressure heater and finally to the condenser hot well. Heaters would be provided with drain level controls to maintain the drain level automatically throughout the range of operation of the heaters. The system would consist of split-range control valves to take the drain to a lower pressure heater or to the condenser through a flash box.

16.5. The unit would be provided with a 60% HP-LP bypass system:(a) To prevent a steam-generator trip in the event of a full export load throw-off and to maintain the unit in operation at house load.

(b) To prevent a steam-generator trip following a turbine trip and enable quick restart of the turbine generator set.

(c) To minimize warm restart duration of the unit after a trip.

(d) To conserve condensate during start-up.

(e) To facilitate quick load changes in both directions without affecting the steam generator operation during start-ups.

FEED CYCLE EQUIPMENT

Condensate Pumps17. The condensate from the condensate hot well would be pumped by 2 x 100% capacity condensate pumps, one working and one standby to the de-aerator, through the gland steam condenser, drain cooler and low pressure heaters. Two pumps would be provided for each 600 MW unit. The pumps would be vertical, cannister type, multistage centrifugal pumps driven by AC motors.

Boiler Feed Pumps

18. Feed water would be pumped from the de-aerator to the steam generator through the high pressure heaters by means of 3 x 50% capacity boiler feed pumps (Two working steam turbine driven pumps and one AC motor driven standby pump). The boiler feed pumps would be horizontal, multistage, centrifugal pumps of barrel type with variable speed hydraulic coupling. Motor drive BFP will be used during start-up.Low Pressure Heaters

19. The low pressure heaters would be of shell & tube type with U-shaped stainless steel tubes, with their ends rolled in carbon steel tube sheets.

Deaerator

20. The de-aerating feed water heater would be a direct contact, variable pressure type heater with spray-tray type or spray type of de-aeration arrangement. The feed water storage tank would have a storage capacity adequate to feed the steam-generator for 6 minutes when operating at MCR conditions.

High Pressure Heaters

21. The high pressure heaters would be of shell & tube type with carbon steel U-tubes welded into carbon steel tube sheets. The HP heaters would be provided with a de-superheating zone and a drain cooling zone in addition to the condensing zone.

Gland Steam Condenser22. A surface type gland steam condenser would be used to condense the gland steam exhausted from the turbine glands. The gland steam condenser would be of single-pass type with the main condensate flowing through the tubes to condense the steam. Exhausters would be provided to evacuate the air from the shell side and maintain the shell at the required negative pressure.

TURBINE LUBE OIL AND CONTROL FLUID SYSTEM

23. A complete lubricating oil system would be provided for the steam turbine generator unit. The control fluid system may be fully separated from the lubricating oil system or integrated with the lube oil system as per the turbine manufacturers standard. The lube oil system would be comprising of lube oil pumps, main oil tank, lube oil coolers, lube oil filters, piping, valves fittings etc. The control fluid system would have its own pumps, motors, coolers, strainers, piping, valves and fittings.

TURBINE LUBE OIL PURIFICATION SYSTEM

24. In the lubrication cycle for the turbine-generator, the lube oil comes in contact with water, air and metal particles which cause deterioration of the lube oil. In order to prolong the life of the lubricating oil and the parts served by the lube oil, suitable purification equipment is required to be provided to remove the contamination and restore the oil to acceptable conditions.

25. The continuous bypass method of lube oil purification is proposed to be adopted. In this method, about 20% of the total oil in the turbine oil system is circulated continuously through the lube oil purifier. Since the condition of a portion of the oil is being restored continuously, impurities are controlled to within permissible values. The lube oil purification system would be Centrifuge-type lube oil purifier.

26. Each lube oil purifier would be capable of purifying lube oil at the rate of 20% of the total charge per hour.

CONDENSATE POLISHING UNIT27. Since fresh water is proposed to be used for this power plant, condensate polishing unit is not envisaged. However, necessity of the same may be examined at the time of detailed engineering.

FUEL OIL SYSTEM

28. The fuel oil system would be designed for the use of LDO for start-up & heavy fuel oil (HFO) for load carrying & flame stabilisation purposes.

29. The HFO requirement would be about 720 m3/day during peak demand. The peak demand is envisaged when the unit is under trial operation. During normal operation the HFO requirement is expected to be about 60 m3/day. Based on statistical average oil consumption of 2 ml per kWh and PLF of 80 %, the annual HFO requirement would be about 16,500 KL.30. Oil is envisaged to be supplied from nearest terminal by using road tankers to the site. 7 days of oil storage is considered adequate during trial operation. Hence, a total HFO storage capacity of 5000 m3 has been envisaged.

CHEMICAL DOSING SYSTEM

31. Phosphate dosing system would be provided to ensure chemical conditioning of the steam generator drum water so as to prevent scale formation. In addition, hydrazine / ammonia dosing system would be provided to ensure chemical conditioning of the feed water by removing the dissolved oxygen and carbon dioxide present in the feed water. The phosphate solution would be added directly into the steam-generator drum. The hydrazine / ammonia solution would be injected into the feed water at the feed water pumps suction (continuous basis) and at the condensate extraction pumps discharge (only during start up).

32. Both high pressure phosphate dosing system and low pressure hydrazine / ammonia dosing system would comprise solution preparation-cum-metering tanks with motorised agitators, two positive displacement type dosing pumps, piping, valves, instruments and local control panel. Each dosing pump would be sized to cater to the 100% dosing requirements of each of the 250 MW unit.

CHAPTER VIII

INSTRUMENTATION AND CONTROL SYSTEM

DISTRIBUTED MICROPROCESSOR BASED CONTROL & MONITORING SYSTEM

1. Microprocessor based distributed control system with state of art Man - Machine Interface (MMI) is proposed to provide a comprehensive integrated instrumentation and control system including the functions of Data Acquisition System (DAS) to operate, control and monitor the steam generator and auxiliaries, steam turbine generator and auxiliaries and the balance of plant systems with a hierarchically distributed structure.

2. The Distributed control system (DCS) would use the state of the art technique of functional distribution of control and monitoring to reduce the risks associated with failure of any single controlling unit. The DCS has complete control capabilities that include closed loop control, open loop control, computation and interfacing for data acquisition, graphic displays, logging, annunciation, data storage, retrieval, performance calculations and management information system. The system allows for CRT operation from the control desk. The communication from the control desk operators interface to the electronic hardware is over a data highway. The system is provided with redundancy at various levels thereby ensuring reliability of the system.

3. The distributed microprocessor based system proposed is functionally distributed. In the functionally distributed microprocessor based system, electronic cubicles would be located in a centralised location with centralised operation from the control room. Remote I / O modules are envisaged for acquiring switchyard signals in the main control room.

4. The instrumentation and control system would integrate the functions of plant monitoring, control and information systems. The system functions would be distributed in a hierarchical system structure to facilitate the task of integration, co-ordination and autonomous operation of plant sub-systems / equipment depending on the plant operation mode. The plant information system would perform the functions of data logging, operation reports, unit performance monitoring and plant start-up and shutdown guidance. All equipment and processes in the unit would be controlled and monitored from central unit control room. The unit control room houses unit control desk and related power supply and system cabinets.

5. A dedicated Microprocessor based DCS of uniform hardware with state-of-the art MMI covering the following is envisaged :

(a) SG integral controls like burner management system, secondary air damper control, soot blowing, high pressure by-pass system and steam temperature control.

(b) TG integral controls like automatic steam turbine run-up system (ATRS), turbine protection electro-hydraulic turbine controls (EHTC), automatic turbine tester (ATT), turbine stress evaluator, low pressure by-pass system and gland steam controls

(c) Balance of plant controls including regenerative cycle controls

The DCS envisaged is independent for each unit except at Management Information System (MIS) level and at the shift charge engineers level which is common for both the units.

UTILITY PACKAGES

6. Utility packages like coal handling system, ash handling system, DM Plant, Air Compressors and Fuel oil system are proposed with dedicated stand-alone I&C system. Air conditioning system would be microprocessor-based system. Chemical dosing system would be relay based. The control of the packages located in a control room nearer to the respective equipment. Suitable interface (hardwired and /or serial) would be provided with the plant I & C system in the main control room.

UNIT CONTROL DESK

7. The unit, functional group / drive level control and operation of all main plant equipment including generators, transformers and auxiliaries would be from a set of monitors mounted on a control desk.

8. The unit control desk (UCD) would house the following items :

(a) Monitors for operation, control and monitoring of steam generator, turbine generator and auxiliaries.

(b) Alarm monitors

(c) Telephone handsets

9. All these monitors are supported by the following peripherals which are located in the control room :

(a) Graphic printers (colour)

(b) LaserJet printers

(c) Character printer (Operators action)

10. The operator can perform the following operations of main plant and balance of plant from monitors in the UCD through key boards. Emergency stop LPBs would be provided for all drives :

(a) Operation of all control valves, control dampers, motor operated valves, interlocked isolating valves and dampers, non-interlocked isolating valves & dampers, motor operated bypass valves of control valves, warm-up valves, drain valves and vent valves in the steam generator, turbine generator and auxiliaries and auxiliary electrical systems.

(b) Operation of pumps and fans associated with the steam generator, turbine generator, feed cycle and other auxiliary systems.

(c) Call for plant overview, group display, individual loop display, etc. and carry out associated control operations.

11. A separate monitor with keyboard common for 2 units would be provided for the Shift Charge Engineer. However, plant operations from this monitor would be inhibited.

Electrical Control Panel (ECP)12. The ECP would comprise of the generator controls including the monitoring, control and annunciation for the electrical auxiliary system. The mimic of the electrical system would be represented up to 415V PMCC level. The 415V normal/emergency switchgear would also be represented.

13. All breakers with synchronizing / check synchronization facility would be controlled from ECP. This would include the GT breakers, 6.6 kV incomers and bus coupler and the 415 V PMCC incomers and bus coupler and the 415 V normal/emergency switchgear incomers. Additionally the SST HT side breakers and tie feeders from the 6.6 kV station switchgear would be controlled from the ECP.

14. In addition, all the above controls would be provided in the main plant DCS.

CONTROL ROOM

15. A control room is proposed to be located on the side of station building. This control room is partitioned into different rooms to house the following equipment :

(a) Unit Control Desk (UCD) and printers in the main control room (common)

(b) Electrical control room in main control room

(c) The I&C system cabinets, electrical auxiliary cabinets, steam generator and turbine auxiliaries system cabinets in the electronic cubicle room (separate)

(d) Shift charge Engineers monitor with key board and printers in Shift Charge Engineers room (common)

(e) Maintenance Engineers monitor with key board in MEE room and printers of I&C, steam generator and turbine system in auxiliary electronics room (common)

(f) Uninterrupted Power Supply System (UPS) in UPS room (separate).

FEATURES OF THE I&C SYSTEM

Sequence of Events Recording System

16. Sequence of events recording system (SER) with adequate capacity would be provided as an integral part of DCS to log trips, cause of trips and other important faults to diagnose the cause of plant trip with a resolution of one millisecond. This would also include switchyard inputs The system would be provided with a dedicated printer located in the main control room.

Annunciation System

17. A Stand alone microprocessor based annunciation system (AS) would be provided with ISA sequence ring back feature. The system has the features of standard ISA sequences. A limited number of annunciation windows of important alarms are proposed to be provided in the unit control desk. Alarm prioritisation is also envisaged. A set of annunciation push buttons would be provided in the unit control desk.

Analytical Instruments

18. Adequate number of analytical instruments would be provided for continuous monitoring of de-mineralised water, condensate, feed water and steam. The analysis would include pH, conductivity, dissolved oxygen, hydrazine and silica measurements.

STEAM AND WATER SAMPLING SYSTEM

19. Various steam and water samples would be routed to a centralised place and cooled to the required temperature before entering analysers / cells. The complete hardware associated with this sampling system and cells is mounted in a sampling rack with facility for grab sample. The analysers are located in a separate panel near the sampling rack in an air-conditioned environment. Both the sample rack and analysers are located in a central place with the analyser panel section partitioned for air-conditioning.

CONTROL VALVES

20. All control valves would have 15% excess capacity over and above the design flow value.

FINAL CONTROL ELEMENT ACTUATORS

21. All final control elements (control valves and control dampers) would have actuators of pneumatic / hydraulic type. The control valve design would be suitable for the required fail-safe conditions of process / equipment.

22. All actuators would be sized so that the final control elements operate properly even when the upstream pressure exceeds 110% of maximum value. Pneumatic actuators would be provided with air failure lock and remote release, limit switches, adjustable minimum and maximum stops, load position indicators, positioners, electronic position transmitters and solenoid valves in accordance with the system requirements.

FIELD INSTRUMENTS

23. Field transmitters, switches and temperature elements with adequate redundancy would be provided to meet he interlock/control requirements of the power plant. Minimum number of local instruments/indicators would be provided to enable local operators to supervise and monitor equipment / process operation.

AIR SUPPLY FOR PNEUMATIC EQUIPMENT

24. Oil free, dry instrument air from instrument air header at a pressure of 6 - 8 bar (g) would be drawn for various instrument auxiliaries like control valve positioners, control damper positioners, I/P converters, etc. Each of these pneumatic equipment which requires air supply at different levels would be provided with an air-filter regulator.

POWER SUPPLY

25. An uninterrupted power supply (UPS) system would be provided to cater to 240 V AC, single phase, 50 Hz, 2 wire power supply requirements of instrumentation and control systems viz. man-machine interface equipment, analysers, receiver instruments, and annunciation system. ( 24 V DC system would be provided for the control cabinets housing processor, communication modules and I/O modules.

.TESTING AND CALIBRATION INSTRUMENTS

26. Testing and calibration instruments as required for maintenance of the field instruments would be provided.

CABLES

27. Individual pair shielded and overall shielded twisted pair copper cables would be used for analog signals and overall shielded cables would be used for digital signals. All these cables are armoured. The overall sheath would be of FRLS. The size of the wire would be 0.5 sq.mm FRLS, 1.5 sq.mm copper control cable would be used for cabling between MCC and Control system. Compensating cables would be provided for connecting the thermocouple inputs to the control system. The interconnecting cables between any two cabinets and between cabinets and panels would be of prefabricated type.

INSTRUMENTATION PIPES / TUBES AND FITTINGS

28. For all pipe mounted instruments, pipes and fittings of appropriate material would be used. For all high pressure and temperature services (above 62 bar (g) or 4250C), two isolating valves of NB25 size would be used. For level and flow instruments NB25 size isolating valves would be used. For other services and measurements NB15 size valves would be used.

29. For remote located instruments like transmitters, tubes and fittings of appropriate material and rating would be used. Open type transmitter racks would be provided to group and mount all pressure, flow and level transmitters. Temperature transmitters would be head mounted. Junction boxes would be provided for termination of all field switches like pressure, temperature and level.

CONDITION MONITORING SYSTEM

30. A microprocessor based diagnostic and data management system complete with vibration and other sensors would be provided for the steam turbine and all HT (6.6 kV) drives/ motors of boiler and turbine islands and CW pumps.

POLLUTION MONITORING

31. Continuous SO2 / NOx and particulate monitoring is envisaged in the stack, to meet the statutory requirements. Oxygen and CO measurements are envisaged in the flue gas duct.

EARTHING

32. Separate electronic earthing system with dedicated pits would be envisaged as part of DCS system.

MASTER CLOCK

33. A stand-alone master clock system with suitable time formats for synchronising DCS system clock and a chain of clock system to be located at strategic locations in the entire plant with satellite time would be envisaged.

CHAPTER IX

WATER SYSTEMSPLANT WATER REQUIREMENT The total plant water requirement for the 2 x 600 MW power station is indicated for the 1st stage of 1200 MW capacity in Table IX-1 as below. The total water consumption for the ultimate capacity of 2000 MW plant will be proportionately increased.TABLE-IX.1Plant Water RequirementsSl. No.ItemEstimated Quantity

M3/hrM3/day

1. Make up water for condenser and other auxiliaries384092160

2.Service Water2405760

3.Plant and colony potable water1804320

4.DM water for SG make-up .1202880

6.Miscellaneous (for filter backwash, DM plant regeneration, clarifier blow down and evaporation loss from Raw water storage tank)3007200

7.Miscellaneous (including evaporation loss in pits)1202880

Total water requirement4,800115,200

1. It is assumed that requirement of water for ash handling and coal handling systems would be met from condenser cooling water system blowdown.

2. The proposed scheme of water systems for the 2 x 600 MW units for stage I of the proposed power plant is shown in Exhibit - 07. The water systems consists of various sub-systems listed below and discussed in the subsequent paragraphs of this chapter :

(a) Raw water supply and pre-treatment system

(b) Condenser cooling water (CW) system

(c) CW Make up water system

(d)Auxiliary cooling water (ACW) system (DM Water)

(e)Water treatment (Demineralised water (DM) system)

(f)Service & potable water system

(g)Fire protection system

(h)Effluent treatment Plant

RAW WATER SUPPLY SYSTEM

3. Proposed System

Raw water is envisaged to be drawn from Govind Vallabh Pant Sagar (GVPS) located at about 37 km from the plant site. The river water is pumped to the power plant premises into a raw water pond having about 2 days water storage capacity to take care of any vagaries of water flow through pipeline due to unforeseen maintenance etc. Intake structure at GVPS would be designed for ultimate capacity of plant. However pumps and transport pipes would be installed in stages.4. Raw Water Storage and Treatment

The raw water (which is basically river water) is expected to have high turbidity / suspended solids especially during monsoon. Since the quality of influent water required for the various systems in the plant is clarified water (with turbidity and suspended solids less than 50 ppm), it is proposed to provide clariflocculator / type clarifiers two (2) nos. for CW make-up / service water and one (1) no. for DM plant.

5. Raw Water Distribution

From the clarifiers, raw water would be transmitted by gravity to clarified water storage tank. This tank would be supplying raw water to various consuming points such as condenser cooling make-up, DM plant, Service water, Fire protection water etc.

6. Clarified Water Storage Tank and Pump House.

The clarified water from the clarifier would be stored in a clarified water storage tank of capacity 9,600 cu.m which would be in two (2) compartments feeding to a common sump to facilitate cleaning and maintenance. The clarified water storage tank would have reserve storage for fire protection system, which is about 1,500 cu.m capacity. Separate storage tank of 600 cu.m capacity would be provided for DM plant.

7. Supply of Clarified Water to Various Consuming Points

The required condenser cooling water make-up would be flowing by gravity to the CW pump house forebay. Requirement of other consuming points would be pumped by the following pumps :

(i) DM plant supply pumps

(ii) Fire water pumps

(iii) Service water pumps.

CONDENSER COOLING WATER (CW) SYSTEM8. Cooling Towers

Recirculation type cooling system with either forced draft or Natural draught cooling towers (NDCT) 2 Nos. 1 for each unit is proposed for CW system for each stage of the proposed station. The cooling tower would be designed for a cooling range of about 10 deg C and an approach of 4.5 deg C. Tower construction would be of RCC with PVC film type fills.

9. Cooling Water (CW) Pumps

Five (5) CW pumps each of 50% capacity are proposed for the 2 x 600 MW power station (2 pumps meeting the CW requirement of each unit and one common standby) for each stage of the proposed station. These pumps would be installed in individual chambers connected to a common CW fore bay. Each pump chamber would have provision for installing coarse screens and stoplogs. The CW pumps would be located in the pump house. An EOT crane of suitable capacity would be provided in the pump house for handling the pumps and motors during maintenance.

10. RC Channels

The CW flow from the cooling tower basins is proposed to be conveyed by gravity to the common CW forebay and pump house of RC rectangular open channels. The channels are designed to resist maximum level fluctuations expected under transient flow condition.

11. CW Forebay and Pumphouse

The total CW flow proposed to be discharged from the open channel to a common forebay and pump house. The forebay is designed to ensure equi-distribution of flow to the CW pumps as well as to limit the entrance velocity at the CW pump house.

12. CW Inlet and Outlet Conduits

From the CW pump house, the CW discharge is proposed to be conveyed to the condensers located in the station building, through CW inlet conduits. These conduits would be either of mild steel construction or of RCC tunnels. The hot water from the condensers is proposed to be conveyed back to the cooling towers through CW outlet conduits which would also be either mild steel or RCC tunnels.

13. Valves and Specialties

Motor operated butterfly valves would be provided at the discharge of the CW pumps and the condenser inlet / outlet piping to facilitate isolation and control. Expansion joints are proposed in the CW pump discharge lines and condenser inlet and outlet lines to take care of any misalignment, thermal expansion, etc., and to facilitate erection and maintenance. The CW pumps and their discharge valves would be suitably interlocked to result in a co-ordinated operation.

14. CW Blowdown and Make-Up Water Requirements

Make-up water requirement of CW system is obtained as the sum of drift and evaporation losses from the cooling tower and blowdown from the CW system (by way of water drained from the hot water conduit of the CW system). In order to conserve water, the blowdown would be utilised to meet the water requirement of the ash handling and coal handling systems.

15. The assumed analysis of raw water (make up water) is presented in Appendix-3. Based on this water analysis, a cycle of concentration (COC) of 5.0 has been adopted for CW system. The CW blowdown would be taken from the condenser outlet. The blow down water from the condenser outlet would be utilised in the ash / coal handling systems, horticulture purpose and excess blow down water is led to guard pond.

16. To prevent scaling arising due to the operation of CW system with a higher COC, chemical dosing system (with scale inhibitor / dispersant) is envisaged. In order to prevent /minimise growth of algae in the CW system, Chlorine dosing system is envisaged. Side stream filtration plant is also envisaged for the CW system.

17. Raw Water System Chlorination

In order to prevent / minimise the growth of algae in the raw water system, chlorine dosing is proposed. Provision would be made for shock dosing and continuous dosing. However, the continuous dosing rate would be adjusted during operation phase to meet the chlorine demand.

AUXILIARY COOLING WATER (ACW) SYSTEM

18. The ACW system meets the cooling water requirements of all the auxiliary equipment of the TG and SG units such as turbine lube oil coolers, generator air cooler, vacuum pump, ash cooler, exciter air coolers, Seal Pot, combustor spies valves, ID / SA / PA fan bearing oil coolers, BFP auxiliaries such as lube oil coolers, working oil coolers, drive motors, etc., condensate pump bearings, sample coolers, emergency DG sets and air compressors.

19. For the ACW system, a closed loop system using passivated DM water as a cooling medium is proposed. The DM water is circulated through the auxiliary coolers by three (3) 50% capacity (2 working + 1 standby) ACW pumps. The hot water from these auxiliaries is cooled in the plate type heat exchangers 2 Nos. by the circulating water tapped from the main CW circuit and pumped by CCW pumps.

20. An ACW overhead tank of 20 cu.m capacity is proposed to ensure positive suction to the ACW pumps and also serve as the source of make-up to the ACW system.

WATER TREATMENT PLANT

21. The water treatment plant broadly consists of DM pre-treatment plant, filtration and DM plant.

22. The DM pre-treatment consists of :

(a) Chlorination system in the form of sodium hypochlorite to destroy organic matter and algae.

(b) Alum / polyelectro type dosing system for the purpose of coagulation.

23. The filtration plant consists of three (3) vertical pressure sand filters to remove turbidity and suspended solids. Back-washing of filters would be done by means of gravity flow from filtered water storage tank. Part of the filtered water would be stored in filtered water storage tank which would be located on the roof of water treatment plant building. This tank would supply water for filter backwash and potable water system. Water would be supplied to the filtration plant by means of three (3) nos. (two working + one standby) WT plant supply pumps. The WT plant supply pumps would take suction from the clarified water storage tank and would be located in the clarified water pump house.

24. De-chlorination Equipment

Activated carbon filters would be used for dechlorination. These filters would also remove any organic, grease, oil etc. present in the water.

DM Plant25. The DM plant would meet the requirements of steam generator (SG) feed water make up, ACW system make-up and plant / colony potable water. It would be designed for a total output of about 3,000 m3 / day of DM water based on SG feed water make up at 3% MCR. It is proposed to provide three (3) (two (2) working + one (1) standby) streams DM plant, each stream designed for an output of about 1500 m3 / day with 16 hours productive run time. Each stream of the DM plant would consist of the following:

26. Cation Unit

Filtered and dechlorinated water would pass through the cation units. The cation unit would be designed to limit the sodium slip within 1.0 ppm as CaCO3.

27. Degasser System

The effluent from SAC units would then pass through a forced draft degasser tower to limit the CO2 to 5 ppm as CO2. For the degasser tower two (2) nos., 100% capacity degasser air blowers would be provided. The degassed water would be stored in degassed water storage tank. Three (3)( two working + one standby) degassed water transfer pumps would be provided for transferring the degassed water to the anion units.

28. Anion Units

The degassed water transfer pumps would pump degassed water through strong base anion (SBA) unit. SBA unit would be designed to restrict the silica slip within 0.1 ppm as CaCO3.

29. Mixed Bed (MB) unit

The final polishing of DM water would be done in MB unit. The MB unit would be designed to limit the silica less than 0.02 ppm as SiO2 and conductivity would be restricted to 0.1 micro mho / cm at 250C.

30. DM water from the mixed bed units would be led to the two DM water storage tanks. The DM water from the DM plant storage tanks would be pumped to condensate storage tank by three nos.(3)( 2 working +1 stand by) DM water transfer pumps.

31. Regeneration System

30 % Hydrochloric acid and 48% sodium hydroxide would be used as regenerants for the purpose of regeneration of cation and anion resins respectively. The equipment of regeneration system would comprise bulk acid and alkali storage tanks, acid / alkali transfer pumps, acid / alkali solution preparation and measuring tanks, ejectors and all associated piping / valves, etc. two (2) nos., each bulk acid and alkali storage tanks would be provided to meet the requirement of both the streams. Each of the tank would be sized to hold 15 tonnes of respective chemical.

32. Neutralising System

The acidic and alkaline effluents from DM plant and the filter backwash would be led to a neut