india first 660mw

Installation of APL India’s First

660 MW Supercritical Unit at

Mundra

Sundara Kavidass

Vice President , Engineering Services

Adani Power Ltd, Ahmadabad

July 20, 2011

1

Presentation Overview

• Introduction

• Supercritical technology

• Design aspects of 660 MW unit

• First 660 MW Project implementation

• Operating Experience

• Conclusion

2

Introduction

• India’s current installed capacity is 156,784

MW

• Projected additional power demand is 95,750

MW up to 2012

• Plan to add 1,58,124 MW of power generation

capacity in year 2007-17 (ten years)

• Adani Power Limited is contributing to add

power generation capacity

3

What is Supercritical Technology?

• The supercritical technology is the thermodynamic state wherethere is no clear distinction between the Water and Steam phase

in the Rankine Cycle

• Water reaches to steam state at a critical pressure above 22.1 MPa

at 374 oC.

4

Rankine Cycle

• The “efficiency “of the thermodynamic process is the heat energy

fed into the Rankine cycle is converted into electrical energy.

• Heat energy input to the Rankine cycle is kept constant, the output

can be increased by selecting high pressures and high temperatures.

• The key components are supercritical once through boiler and high

pressure & high temperature steam turbine.

Rankine Cycle Subcritical Unit

1 - 2 > CEP work

2 - 3 > LP Heating

3 - 4 > BFP work

4 - 5 > HP Heating

5 – 6 > Eco, WW

6 – 7 > Superheating

7 – 8 > HPT Work

8 – 9 > Reheating

9 – 10 > IPT Work

10–11 > LPT Work

11 – 1 > Condensing

Rankine Cycle Supercritical Unit

1 - 2 > CEP work

2 – 2s > Regeneration

2s - 3 > Boiler Superheating

3 – 4 > HPT expansion

4 – 5 > Reheating

5 – 6 > IPT & LPT Expansion

6 – 1 > Condenser Heat rejection

Various Regimes of Pressures

7

Effect of Increasing Steam Temperature and

Pressure on Cycle Efficiency

8

CONDENSER

`

No. 3

HP Heater

BFBP

BFP

CEP

GSC

LP Heater

#1

LP Heater #3

Deareator

LPT IPT HPT

No. 2

HP Heater

No. 1

HP Heater

LTRH I/L

Header

LTRH

ECO I/L

Header

LTSH

ECO

LP Heater #2

HP

BFWP

CRH

DRUM

DOWN

COMER

Roof

Tube

I/L

Header

PLATEN

SHFSH

FRH

Water Wall

MS

HRH

HP-BP

LP-BP

WW LOWER

Header

GG

A B

BA

A B C

Water And

Steam Path

Subcritical

Natural Circulation Once Through SystemVs.

10

660 MW SC Unit Design Coal Data

Parameters Value Parameters Value

Moisture % 33.00 Moisture % 10.0

Ash % 4.02 Ash % 37.0

F C % 32.50 F C % 25.4

V M % 30.48 V M % 27.6

GCV Kcal/kg 4500 GCV Kcal/kg 3927

MUNDRA TIRODA

660 MW Unit Design Aspects

Boiler

Description Unit Mundra Data Tiroda Data

Furnace Size :

Height :

m x m

m

20.4023x20.072

68

19.824x17.64

69

WW lower header elevation m 7 9

Roof elevation m 75 78

Transition header elevation m 50.47 53.34

Furnace plan heat release Kcal/m2 3.419 x 10^6 4.486 x 10^6

Furnace volume heat release Kcal/m3 58.05 x 10^3 68.07 x 10^3

Water Wall area/ No of tubes m2 4667/ 1468 5952 / 1338

Superheater area m2 12034 14954

Reheater area m2 24395 23615

Economizer area m2 12542 12606

12

Supercritical Boiler Features

Bottom spiral & top vertical tube furnace arrangement

• Once through design feature is used for boiler water wall design

• The supercritical water wall is exposed to the higher heat flux

• Utilize intensive radiant heat transfer in the furnace firing zone

• Spiral tube wall design (wrapped around the unit) with high

mass flow & velocity of steam/water mixture through each spiral

tube (2630 kg/m2/s & mass flow velocity for vertical tubes ~

1259 kg/m2/s)

• Higher mass flow improves heat transfer between the WW tube

and the fluid at high heat flux.

• Improved materials are utilized for superheater and reheater

tubes

13

No. 1

HP Heater

BFBP

MD-BFP

CEP

GSC

No.7AB&8AB

LP Heater

No.5 LP Heater

DEAERATOR

CONDENSER

LPT LPT IPT HPT

No. 2

HP Heater

No. 3

HP Heater

BRCP

LTRH I/L Header

LTRH

ECO I/L Header

LTSH

ECO

No.6 LP Heater

HP BFWP

CRP

SEPARATOR

SEPARATOR

DRAIN TANK

ROOF TUBE

I/L Header

SH DIV

Panel

FSHFRH

VERTICAL WATER WALL

MSP

HRP

HP-BP

LP-BP

WW LOWER Header

GG

TD-BFP

A B

BA

A B C

Water And

Steam Path

SC Unit

14

1515

1616

Heat Absorption in 660 MW

Supercritical Boiler

17

% H

ea

t A

bs

orp

tio

n

17

0

10

20

30

40

50

Water wall SH RH Economizer

45%

29.5%

18.5%

7%

Mundra 660 MW

Tiroda 660 MW

0

10

20

30

40

50

Water wall SH RH Economizer

% H

eat

Ab

so

rpti

on

48%

24 %19 %

9%

660 MW Mundra SC Unit

Off-Set Firing

660 MW Tiroda SC Unit

Tangential Firing

PF FIRING OPTIONS - COMPARISON

18

BURNER

BURNER

FIRE

BALL

Coal Burners Arrangement (Mundra)

AA (AIR DAMPER)

A (A ELEVATION COAL NOZZLE)

OA (LDO OIL NOZZLE)

AB (AIR DAMPER)B (B ELEVATION COAL NOZZLE)

OB (HFO OIL NOZZLE)

BC (AIR DAMPER)

C (C ELEVATION COAL NOZZLE)

CC (AIR DAMPER)

DD (AIR DAMPER)

D (D ELEVATION COAL NOZZLE)

OC (HFO OIL NOZZLE)

DE (AIR DAMPER)

E (E ELEVATION COAL NOZZLE)

OD (HFO OIL NOZZLE)

EF (AIR DAMPER)

F (F ELEVATION COAL NOZZLE)

FF (AIR DAMPER)

1687 m

m

19

Coal Burners Arrangement (Tiroda)

Steam Turbine & Heat Cycle

Engineering Design Aspects

Type

(N660.24.2/566/566)

Dongfang Steam Turbine

Impulse type, tandem compound three

cylinders, four flow exhaust, single reheat,

condensing turbine

TMCR Output 660 MW

BMCR Output 694 MW

HP turbine 8 Stages, 2 Stop valves, 4 control valves

IP turbine 6 Stages, 2 Stop valves, 2 control valves

LP turbine Double flow 2x7 Stages

HP heaters 3

LP heaters 4

No of Extractions 8

No of Journal bearings 6

21

HPT IPT LPT A LPT B

CPP

GSC

Condenser

1

HP

H -

1H

PH

-2

HP

H -

3

EXT From CRH

LPH -5LPH -6

LPH -7ALPH -7B

LPH -8ALPH -8B

3

Deaerator

TD BFP

Boiler

CEP3x55%

2x50%

FC

S

5 56 6

From Reheater

1482 TPH

1994 TPH

(MD BFP 1x35%)

78

78 8

778

Condenser

4

2

22

660 MW Turbine Cross Section Overview

23

660 MW Mundra Steam Turbine

24

Features of 660 MW Mundra Steam Turbine

Combined HP & IP Section

Shorter Turbine Length – More Efficient

Reduced No. of Bearings

Reduced No. of Packing segments

Opposite flow in HP & IP Turbines makes thrust force

balanced

Casings upper & lower halves are nearly symmetrical

25

• Coal Mills HP1203 - 6

• FD Fan Axial 2 x 50%

• PA Fan Axial Fan 2 x 50%

• ID Fan Axial Fan 2 x 50%

• APH Regenerative rotary type,

Tri-sector - 2

• ESP 4 passes, 2 sections, 5 fields

• BFP MD BFP-1x35%, TD BFP-2x50%

• CEP 3 x 50%

• CWP 3 x 50%

Key Plant Equipment

26

660 MW Supercritical Unit Design &

Operating ParametersItem Description Unit TMCR Operating

Data

1 SH steam flow rate TPH 1994 2131

2 Superheated steam temp Deg C 571 567

3 SH steam pressure MPa 25.26 23.57

4 RH steam flow rate TPH 1624 1650

5 RH steam outlet temp Deg C 569 567

6 RH outlet pressure MPa 4.36 4.21

7 FW temperature Deg C 288.7 288

8 FW Pressure MPa 28.4 26.93

9 Separator temp Deg C 421 430

10 Separator pressure MPa 27.02 26.37

11 APH flue gas outlet temp Deg C 147 150

12 Total Air Flow ( To Wind box) TPH 2251 2093

13 Back Pressure KPa 10.2 10.3

14 Fuel Flow Rate TPH 323 293.3

15 Turbine Heat Rate Kcal/kWh 1894 1900

16 MW Output MW 660 66327

Material Used for 660 MW Unit

(Mundra & Tiroda)

EquipmentMaterial

Specification

Design

Temperature 0 C

Allowable

Stress in MPa

Water Wall SA213T12 440 103

Low Temperature SH SA213T22 490 80

Final SH SA213T91 590 65

Final SH SA213 TP 347H 590 89

Low Temperature RH SA213T22 355 114

High temperature RH SA213T91 605 65

High temperature RH SA213 TP 347H 605 89

Final SH header SA335P91 590 65

Final RH header SA335P91 605 65

Turbine rotor New 12Cr forging 590 65

HP Turbine 1st stage

Blades2Cr11Mo1VNbN 590 65

28

Recommended Water Chemistry for SC Units

All Volatile Treatment

(Start Up)

Oxygenated Treatment

(Operation)

Description Unit

Feed

Water

Quality

CondensateMain

steam

Feed

Water

Quality

CondensateMain

Steam

pH 9.0 - 9.6 9.0 - 9.6 9.0 - 9.5 8.0 - 9.0 8.0 - 9.0 8.0 - 9.0

Dissolved

Oxygen µg/l < 5 < 10 30 - 150 < 10

Hydrazine µg/l < 50

Cation

ConductivityµS

/cm < 0.2 < 0.15 < 0.2 < 0.15 < 0.12 < 0.15

Silica µg/l < 20 < 20 < 20 < 15 < 10 < 15

Iron µg/l < 10 < 5 < 10 < 10 < 5 < 10

Sodium µg/l < 5 < 3 < 5 < 5 < 3 < 5

Chloride µg/l < 5 < 3 < 5 < 3

Copper µg/l < 3 < 2 < 3 < 3 < 2 < 3

29

EFFECT OF CYCLE CHEMISTRY – KEY PARAMETERS

Parameter Potential Cause Long -Term Impact

Low pH 1. Condenser tube leak

2. Upset in water Treatment

3. Improper chemical cleaning

4. Improper CPU operation

1. Hydrogen damage

2. Excessive deposits lead to BTF by

overheating.

3. Potential for FAC,

4. Stress corrosion cracking.

High pH 1. Excess dosing of NaOH

during startup

2. Upset in water treatment.

3. Improper CPU operation.

1. Caustic gouging,

2. High conc. deposit leads to turbine

damage

Chlorides 1. Condenser tube leak

2. Upset in water treatment.

1. Hydrogen damage

2. Pitting on economizer & turbine

blades

3. Stress corrosion cracking in LP

turbine

Sodium 1. Condenser tube leak

2. Upset in water treatment

plant

3. Excess dosing of NaOH

during startup

1. Caustic gouging

2. Deposits on turbine blade lead to rpm

reduction.

BOILER WATER TREATMENT FOR SC UNIT

All VolatileTreatment (AVT)

Ammonia & Hydrazine added at feed water & condensate

Boiler water pH to be maintained 9.0 – 9.5

Dissolved oxygen in feed water is <7ppb.

Magnetite layer formation for corrosion protection.

Used during start up to minimize contamination in the system.

Oxygenated Treatment (OT)

Ammonia & oxygen added to feed water & condensate

Boiler water pH to be maintained 8.5 – 9.0.

Dissolved oxygen in feed water is 50 – 150 ppb.

Hematite layer formation for corrosion protection.

Benefits of OT

Minimize FAC in feed water piping & economizer inlet header.

Corrosion product transportation is minimized. Helps to reduce

thermal fatigue , overheating & turbine fouling.

Formed Hematite layer is stronger than Magnetite layer for corrosion

protection.

Operation & Maintenance Challenges

• Availability of expertise in the industry

• Operator training including simulators & External

Agency

• Maintaining cycle chemistry

• Limited equipment standby (or) redundancy

• Maintaining adequate spares

• Proper cycling and control load operation

• Coal quality

• Plant Equipment Margin

• Lack of SC operating experience

32

Cold Start up Curve for 660 SC Unit

33

SC Unit Load Ramp up Rate

0

20

40

60

80

100

120

-60 -10 40 90 140 190 240 290 340 390

% L

oad

Time

Recommended Practice

Not Recommended Practice

Supercritical unit cyclic operation

Operating Experience of 660 MW Unit

• Unit has operated beyond 660 MW

• Unit is operating at sliding pressure mode

• Required cycle chemistry - OK

• Power evacuation system - Grid Restriction

• Coal /Ash handling system - OK

• Boiler efficiency (85%) & heat rate – 2200 KCal/kWh

• No significant slagging / fouling for Indonesian coal

• Combustion efficiency - 98 - 99%

• No major maintenance issues on SC boiler & Steam Turbine

• Meeting environmental requirements (pm < 50 mg/Nm^3)

36

Benefits of Supercritical Unit

• Higher unit cycle efficiency (40 - 42%)

• Superior environmental performance (< 8 % CO2 reduction)

• Lower heat rate and electricity generation cost is lower

• Lower water losses because no continuous blow down

• Reduced auxiliary power consumption

Environmental Benefits

• Reduce carbon dioxide (CO2) emissions with carbon credit

within the Rankine cycle

37

Highlights of E&C of 660 MW SC Unit

• Erection and Commissioning were successfully completed in less than 36 months

• Green field power project and all the environmental clearances were received in time

• No site pilings are required

• Contractor brought major handling equipment from China

• APL’s QA/QC team are placed in china to ensure the quality.

• Ensured sequential delivery of the equipment to meet the schedule and Mundra Seaport is very close to the plant

• Project commissioning was done through DCS

• Good team work between Chinese and Indian project teams

• Received good cooperation from state and central govt. authorities 38

Conclusion

• Unit #5 E&C was completed in 36 months

• Unit operating performance as per design

• SC Coal fired power plant cycle efficiency increased by 3% and

contributes reduce CO2 emissions by 5 to 8%

• APL is installing several 660 MW SC units across the country

• APL goal is to install 20,000 MW by end of year 2020

• India’s power demand can be met utilizing larger size SC /USC

Technology

• SC technology can be operated economically as well as

environmentally acceptable manner

39

21-Jul-11

Power Business Goal - 20,000 MWAdani Power Limited

Complete excavation for main

plant foundations

41

Concrete roads all over plant

area - Main plant front road

42

APH & duct erection start before ceiling

girder

43

Erection of Coal Bunkers

simultaneously with Main Structure

44

ESP electrodes erection with

exclusive tower crane

45

Furnace hopper assembly with all buckstay

arrangements and erection in two parts only

46

Furnace hopper erection in two

parts

47

Generator stator 276 MT lifting by

2x80T EOT crane

48

Rear arch assembly at site & erection

from boiler top with tower crane

49

Water wall assembly at site & Erection

from Boiler top by tower crane

50

DIVISIONAL SUPER HEATER

PANEL

SPIRAL WATER WALL

BURNER PANEL

FINAL SUPER

HEATER

ARCH PANEL

51

LTSH COILS

ECONOMISER COILS

ECONOMISER I/L HEADER

ECONOMISER

O/L HEADER

52

53

54

SEPERATORS

55

56