[CASE STUDY]

Retrofit of Boryeong

Coal Fired Power Plant Unit 1&2

Contents

1. Introduction

3. Retrofit of Boryeong Unit 1&2

2. Guidelines for the Life Management

4. Conclusion

1

1.1 KOMIPO

12.6% out of total Korean domestic power generation facilities (74,410 MW)

SeocheonThermal P/P

SeoulThermal P/P

IncheonThermal P/P

JejuThermal P/P

YangyangP/S/P/P

BoryeongThermal P/P

Boryeong TPP

Boryeong CCPP

Seoul TPP

Incheon TPP

Incheon CCPP

Seocheon TPP

Jeju TPP

Yangyang PSPP

Renewable

Name

9,399 MW

Bituminous coal

LNG

LNG

LNG

LNG

Anthracite coal

Bunker oil / Kerosene

Hydraulic

Wind / Solar / Fuel cell / SHPP

CapacityFuel

4,000 MW

1,800 MW

387.5 MW

500 MW

1012.4 MW

400 MW

285 MW

1,000 MW

14.05 MW

Total

1.2 Boryeong # 1,2

UnitCapacity

[MAR]Completion

Retire

［plan］

Operation

[Hour]

# of

Start-up

Average

Power

Factor [%]

Gross Generation

[Million kWh]

1 510 ’83.12

’15

141,000 190 82.2 76,102

2 510 ’84.09 138,000 150 81.3 74,395

Operation Data

Unit TBN BLR Total

Design 45.48 89.14 40.54

1 44.54 89.14 39.70

2 44.32 89.14 39.50

Efficiency

Item Emission ~ ’09 ’10 ~

SOx[ppm] 150~240 270 100

NOx[ppm] 200~290 350 150

Regulations

1.3 Bathtub curve

Technical basis

Item EOHElapsed

Year# of

Start-up

criteria > 100,000 Hr 20 400

Technicalbasis

> 50% of Creep Worn out> 50% Fatigue

life

Bathtub curve

∙ Failure rate in accordance with aging

2

2.1 Design life

Design life of each plant

Item Coal fired Combined cycle Pumped storage Internal-combustion

Design Life

(year)30 30 50 25

Proper time for each procedure［D : Year of retirement］

No. Procedure Time No. Procedure Time

1 Life Assessment D – 10 4 Confirmation of Method D – 6

2 Master Planningfor Life Management D – 9 5 Planning for Execution D – 6

3 Feasibility Study D – 8 6 Execution of Project D – 5

∙ Reference life of the guideline

2.2 Procedures for Life Management(1)

Main facilities for life assessment

TBN BLR Electric Equipment

∙ HP/IP/LP Blades & Diaphragm

∙ Rotor

∙ Casing

∙ Tube

-Waterwall, S/H, R/H, Eco

∙ Drum

∙ Main STM pipe

∙ R/H STM pipe

∙ Stator & Rotor

∙ Exciter

∙ Transformer

- Main, Aux, Start-up

Life Assessment (D-10)

∙ Reliability & Remaining life evaluation

∙ Analyzing operation and maintenance history

∙ Operating and design conditions

2.2 Procedures for Life Management(2)

Master Planning (D-9)

∙ On the basis of life assessment report

∙ Potential life management method

∙ Following procedure and estimated budget

Feasibility study (D-8)

∙ Technical(environmental) and economical feasibility

∙ By professional organization for objectivity

∙ Optimal project method and boundary

2.2 Procedures for Life Management(3)

Confirmation of method (D-6)

∙ Best method based on feasibility study

∙ Specific project execution plan

∙ According to the project execution plan

Execution of project (D-5)

Planning for execution (D-6)

3

3.1 Facility Status(1)

Item Specifications

Stage HP/IP/LP 6/5/6(Double)

Main steam Pressure /Temp 169[kg/cm2] / 538℃

Reheat steam Pressure /Temp 39[ kg/cm2] / 538℃

Maker Toshiba

Turbine

∙ 500MW regeneration reheating impulse TBN

∙ Tandem Compound 3 Cylinder

3.1 Facility Status(2)

Boiler

∙ Sub-critical pressure

∙ Reheating and balance draft

Item Specifications

Type of Boiler Drum

The max amount of continuous vaporization 1,781 [Ton/Hr]

Fuel Bituminous Coal, Light oil

Outlet pressure of Superheater / Reheater 176.4/40.4 [kg/cm3]

Outlet Temperature of Superheater / Reheater 540/540 [℃]

Maker Bobcock and Wilcox

3.1 Facility Status(3)

Gen.

Item Specifications

Rated capacity 613,000KVA

Rated voltage 22,000V

Rated current 16,088A

Rated Frequency 60Hz

Cooling

Stator windings Water

Stator core Hydrogen

Rotor windings Hydrogen

Maker Toshiba

3.2 Retrofit Project

• Life assessment for unit #2’03. 07

• Life assessment for unit #1’03. 12

• Master planning’04. 11

• Feasibility study’05. 02

• Planning for retrofit’06. 04

• Execution of retrofit’08. 10

• Output increasing : 25MW

• Efficiency increasing : 0.8%

• Lifespan extension : 10 years

Goals

Procedures according guideline

3.2 Retrofit Project

Life assessment (#1: ’03.12 / #2 : ’03.07)

∙ During major inspection

□ Turbine

- Low efficiency due to worn out blade and nozzle

- Erosion of IP TBN

□ Boiler

- Remaining life of S/H & R/H : 40,0000 Hr

- Need to Slope tube replacement

□ Generator

- Retaining ring of rotor was corroded

- Stator winding degradation

∙ Overall facility degradation

3.2 Retrofit Project

Master planning (’04.11)

∙ Plan to emergency maintenance during next inspection

ex) 1st Stage of IP TBN & Boiler slope tube

Feasibility study (’05.02)

• KEPCO E&C (former KOPEC)Service company

• Turbine : Toshiba

• Boiler : Bobcock & WilcoxTechnical consultation

• Konkuk UniversityEconomical consultation

∙ Retrofit project as a life management method

3.2 Retrofit Project

Retrofit methods

Method Description Action Plan

1Life Extension

+ Improvement of Thermal EfficiencyHIP Remodeling

2 Case ⅠWay 1 + Improvement of Output

HIP Remodeling

2 Case Ⅱ HIP & LP(L-0, L-1) Remodeling

3 Case ⅠWay 2 + Rise of R/H STM Temp(28℃)

HIP Remodeling

3 Case Ⅱ HIP & LP(L-0, L-1) Remodeling

Ref. Minimal Facility replacement and reinforcement

Performance comparison

Unit Before

Methods

12 3

Ref.Case Ⅰ Case Ⅱ Case Ⅰ Case Ⅱ

Output [MAR] MW 510 515 535 535 535 535 510

Eff.

BLR % 88.09 88.49 88.49 88.49 88.54 88.54 88.09

TBN % 44.32 45.05 45.02 45.27 45.22 45.48 44.32

Total % 38.10 38.92 38.90 39.12 39.10 39.33 38.10

3.2 Retrofit Project

Range of facility replacements

Item

Methods

1

2 3

Ref.Case

ⅠCase

ⅡCase

Ⅰ

Case

Ⅱ

BLR

Tube of Secondary S/H, R/H ○ ○ ○ ○ ○ ○

∙ Expand Heating surface for R/H STM

∙ Eco tube → Primary S/H× × × ○ ○ ×

TBN

HIP Rotor, Nozzle Box

HP/IP Nozzle Diaphragm

HP Inner Casing

○ ○ ○ ○ ○ ○

IP Inner Casing × × × ○ × ×

LSB L-1 Blades & Nozzle × × ○ × ○ ×

LSB L-0 Blades & Nozzle

LP Nozzle Packing× × ○ × ○ ○

LP 1st Nozzle × × ○ × ○ ○

Ele. Eq. GEN Rewinding/AVR & DCS Replacement ○ ○ ○ ○ ○ ○

3.2 Retrofit Project

Balance for ’08~’24 under current power market situation

Unit

Methods

12 3

Case Ⅰ Case Ⅱ Case Ⅰ Case Ⅱ

Income billion

Dollar

362 379 378 378 377

Cost 231 237 236 236 235

Profit 131 142 142 142 142

∙ Under variable scenario of domestic power market

∙ Case 1 & 2 of method 2 & 3

Cost for Retrofit

Item Unit

Methods

12 3

Ref.Case Ⅰ Case Ⅱ Case Ⅰ CaseⅡ

Costmillion

Dollar104 105 118 136 149 104

3.2 Retrofit Project

Synthetic analysis

Item Unit

Methods

12 2 3 3

Ref.Case Ⅰ Case Ⅱ Case Ⅰ Case Ⅱ

Cost USD 104 m 105 m 118 m 136 m 149 m 104 m

Efficiency % + 1 + 1 + 1 + 1 + 1 -

Output % - + 5 + 5 + 5 + 5 -

Economic feasibility - Bad Good Good Good Good Bad

Facility Reliability - Bad Normal Normal Good Good Bad

Investment Risk - Low Low Low High High Low

• Case II of Method 2Optimum

Turbine(1)

3.3 Facility Improvements

After

Before

HP 6 Stage IP 5 Stage

HP 7 Stage IP 6 Stage

HP/IP Stages

Turbine(2)

3.3 Facility Improvements

Bucket Type (HP 1st stage)

Before After

Tangential Entry Dovetail Axial Entry Dovetail

Turbine(3)

3.3 Facility Improvements

Bucket Cover Type (HP/IP)

Before After

Tenon Covered Bucket Integral Covered Bucket

Turbine(4)

3.3 Facility Improvements

Diaphragm (HP 1st stage)

Before After

Nozzle Box Type Nozzle Plate Type

Turbine(6)

3.3 Facility Improvements

Result

UnitEfficiency [%]

Output[MW at MAR]

HP IP LP TBN Total Avg.

1 85.36 91.87 91.95 45.3745.46

(44.43, +1.03)

535

(510, +25)2 84.97 92.17 90.41 45.54

∙ Short manufacturing time (Diaphragm)

∙ Easy to disassemble and assemble (Bucket)

∙ Easy to repair and replace (Diaphragm)

Boiler(1)

3.3 Facility Improvements

Tube Material Upgrade (S/H & R/H)

Tube

Tube material Allowable Temp.

Before After Before After

SSH Inlet SA213T12 T22, T91,T92 538 542

SSH Outlet SA213T22 T91 602 649

R/H #3 Interm SA213T12 T22 538 542

R/H Outlet SA213T22 T91 602 649

- Long-term use, tube scale, diversification of coal

∙ Life consumption rate was about 50~60%

Boiler(2)

3.3 Facility Improvements

Restoring S/H

Before After

Boiler(3)

3.3 Facility Improvements

Expanding Eco.

Before After

Boiler(4)

3.3 Facility Improvements

Result

Efficiency of boiler [%]

Unit Before After Balance

1

89.14

89.96 + 0.82

2 90.63 + 1.49

∙ Total heating surface increased by 3,350 m2

∙ Heating surface of the primary S/H increased by 2,264 m2

3.3 Facility Improvements

Gen.

Gen. & AVR

AVR

∙ Rewinding

- Minimizing the power loss : 1,840 → 1,263 kW (-577kW)

- Improving the insulation class ( class B → class F)

∙ Retaining ring material upgrade ( 18Mn-5Cr → 18Mn-18Cr)

∙ Rated capacity : 613 → 626 MVA (+13MVA)

∙ The exciter transformer capacity increasing (4.9MVA → 5MVA)

∙ 3 phase controlled rectifier(PCR)

∙ Static type digital controller tripling

3.3 Facility Improvements

Control System

Control System Before After

Turbine Analog(Toshiba EHC)

Digital(Emersion, Ovation)Boiler Analog(Bailey 820)

Burner Analog(Bailey 861)

∙ Manufacturing was discontinued

∙ Lifespan expired

∙ Over the maintenance limit

3.3 Facility Improvements

Environmental Facility(1)

Desulfurization facilityDeNOx facility

3.3 Facility Improvements

Environmental Facility(2)

Regulations and emission

Item ~ ’09Emission

[before]’10 ~

Emission

[after]

SOx 270 150 ~ 240 100 80

NOx 350 200 ~ 290 150 80

Dust 40 10 ~ 30 30 8

Result

3.4 Result of Retrofit Project

Synthetic Result

□ Project period

#1 : 2009.1.14 ~ 7.25 #2 : 2008.10.23 ~ 2009. 3.31

□ Cost : 225 million dollar

□ Performance improvement of worn-out coal fired power plants

○ Output : Increasing of 25MW(510 → 535MW at MAR)

- Saving construction cost of 42 million dollar

○ Efficiency of power plant : Increasing by 1.44%

- Saving fuel cost of 112 million dollar per 1 unit

□ Life extension by 10 years

Item Before After Remark

Output 510 MW 535 MW + 25MW

Efficiency 39.60% 41.04% 1.44%

Lifetime 2015 2025 + 10 years

Control System Analog Digital

4

4. Conclusion

Boryeong #1,2

• Worn-out

• Reinforced regulation

• Experience of 500MW class retrofit projectPride

• Share experience & contribute globallyCooperation

Retrofit project

• Output

• Efficiency

• Lifespan

Guidelines

for life management

Q & A

Seongwoo YiPower generation department

Korea Midland Power Co., Ltd.(KOMIPO)

Email : executive@komipo.co.kr

Phone : 82 – 70 – 7511 – 1326

Thank you for your attention.

Contact Information