Comparing the thermal power plant performance at variou 2

International Journal Mechanical Engineering and
InternationalJournal ofof Mechanical Engineering Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online) Volume 2, Issue 2, May- July
and Technology (IJMET), ISSN 0976 – 6340(Print) (2011), © IAEME
ISSN 0976 – 6359(Online) Volume 2
Issue 2, May – July (2011), pp. 111-126
©IAEME
© IAEME, http://www.iaeme.com/ijmet.html

IJMET

COMPARING THE THERMAL POWER PLANT
PERFORMANCE AT VARIOUS OUTPUT LOADS BY ENERGY
AUDITING (A STATISTICAL ANALYZING TOOL)

1

Manjinder Bajwa, 2Piyush Gulati

1,2

Asst. Prof., Department of Mechanical Engineering,
Lovely Professional University, Jalandhar, Punjab-144402 (India)
man_bajwa@yahoo.co.in
ABSTRACT
In the present scenario of rapidly growing demand of energy in transportation,
agriculture, domestic and industrial sectors, the auditing of energy has become
essential for over coming the mounting problems of the world wide crisis and
environmental degradation. There are two factors contributing to the increase in the
energy consumption, one is more than 20% increase in world’s population and
another one is worldwide improvement in standard of living of human being. The
industrial sector consumes about 50% of total generated energy. Therefore improving
energy efficiency is the main focus of Energy Auditing. Experiments are carried out
to validate the results, obtained by the Energy Auditing at Panipat Thermal Power
Station in Unit 7th which has maximum power generated capacity of about 250MW.
The auditing of energy is basically determining the efficiency of Unit 7th of PTPS.
Energy Auditing in thermal power plant covers the overall process of data collection
and carrying out technical and financial analysis to evolving specific energy
management action. Energy Audit identifies the performance of each & every
equipment and compares it with the base case.
KEYWORDS: Energy Management, Energy Audit, Power Plant, and Energy
Conservation.
1.0 INTRODUCTION
To meet the growing demand for energy in industries, one of the aims is to
identify the technical support in improving their energy performance through
comprehensive energy audits, implementation assistance, technology audits, and
capacity building. Energy audits help in identifying energy conservation opportunities
in all the energy consuming sectors. While these do not provide the final answer to the
problem, but do help to identify the existing potential for energy conservation, and
induces the organizations/individuals to concentrate their efforts in this area in a
focused manner.

111

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online) Volume 2, Issue 2, May- July (2011), © IAEME

1.1 Energy Audit: An energy audit is a technique for identifying energy losses,
quantifying them, estimating conservation potential, evolving technological options
for conservation and evaluating techno economics for the measures suggested.
i) Assist industries in reducing their energy consumption.
ii) To promote energy-efficient technologies among industry sectors.
iii) Disseminate information on energy efficiency through training programs and
workshops.
iv) To promote transfer of energy-efficient and environmental-sound
technologies to the industrial sectors in the context of climate change.
1.2 Energy Audit Technique: The energy audit evaluates the efficiency of all
process equipment/systems that use energy. The energy auditor starts at the utility
meters, locating all energy sources coming into a facility. The auditor then identifies
energy streams for each fuel, quantifies those energy streams into discrete functions,
evaluates the efficiency of each of those functions, and identifies energy and cost
savings opportunities. The types of Energy Audit are as follows:
G. Insulation Audit
A. Walk through Audit
H. Specific Energy Consumption
B. Total System Audit
I. Hot Steam Analysis
C. Fired Heaters
J. Cooling Systems Audit
D. Boilers/Steam Generations Plant
K. Energy Projects Evaluation
E. Steam System Audit
F. Electrical System Audit
From the above mentioned systems, this research work containing the study of Total
System Audit and its implementation methodology.
1.2 Total System Audit: This approach analysis the total system by detailed analysis
as the total energy data is entered in a master database file. This contains design data
and also the observed data. This approach gives the energy performance of the total
system and identifies areas of improvements on energy cost or energy quantity basis.
This method requires rigorous data entry and analysis.
2.0 LITERATURE REVIEW
Organizational structure of electricity supply industry in India has been
evolutionary in nature. To understand this evolution it would be necessary to go over
the past history of the electricity supply industry. In the year 1883 the first electric
supply undertaking in the country was sponsored by a company, which constructed a
small-generated solution in the city of Surat (Gujrat).
Energy conservation of the systems has become the topic of research in the
recent period. Many researchers investigated and formulated the effects of energy
conservation for the efficient energy usage particularly in industrial sector.
E.Raask [1969], elaborated about tube failures occurring in the primary super heaters
and repeaters and in economizers of coal fired boilers, which are result of erosion,
wear caused by impaction of ash particles.
Pilat et. Al. [1969], discussed about source test cascade impact or for measuring the
size distribution of particles in stacks and ducts and air pollutant emission sources.
This impactor is inserted inside the duct or stack to minimize tubing ball losses and
water condensation problem.
112


Schulz [1974], studied the size distribution of sub-micron particles emitted from a
pulverized coal fired power plant and were measure using two types of cascade
impactors. Scanning electronic microscope photographs shows particles were
spherical with mean size entering and leaving the electrostatic precipitator of 5 and 21/4 micrometers although the slope of curve for each impactor differed.
Neal [1980], abbreviated about the conventional automatic control of boiler outlet
steam pressure by means of the demand to the pulverized fuel mills has been found to
be unstable on some coal fired-boiler turbine units. The frequency response of mills
and boiler are obtained from tests in which the mill demand was perturbed with single
frequency sinusoids. It is impracticable to measure the fuel output from the mills
directly, but this is inferred from oxygen in the flue gas measurement coal/ash
properties.
Doglin [2001], abbreviated after reviewing the current combustion technologies for
the burning pulverized coal with frequent and large fluctuation in coal quality and
load demand, a new concept of quasi –constant temperature combustion for
pulverized coal is purposed.
There are more than fifty researchers whose research in the same field. The main aim
of their research is to conserved the energy for future and reduce the energy loss
during transformations from one form to other.
3.0 INTRODUCTION TO THERMAL POWER PLANT
Thermal Power Station Panipat, a bunching of eight individual units with total
installed capacity of 1360 MW is located about 8 KM in the west of Panipat city on
Panipat-Hissar National Highway and is surrounded by cultivated green fields. In
addition, 640 acres of saline wasteland is earmarked for disposal of ash. The plant is
equipped with a huge residential colony to ensure availability of staff and officers
round the clock. Unit No. 1 was commissioned on 1st November, 1979 Haryana day
by the then President of India Shri Neelam Sanjeeva Reddy with subsequent
commissioning of Units. Table 1 shows the overall means the total performance of 8
Units year by year.
Table 1. Performance of Panipat Thermal Power Station
Year

Generation
(MW)

2000-01
2001-02
2002-03
2003-04
2004-05
2005-06
2006-07
2007-08
2008-09
2009-10

2868.835
2656.030
2856.040
2727.994
4123.94
4992.264
5949.260
5756.5968
8135.6993
9908.1265

Plant Load Auxiliary
Factor (%) Cons. (%)
50.38
46.65
50.02
47.91
61.86
66.26
78.75
71.14
68.53
83.17

11.80
11.75
11.41
11.43
10.67
10.14
10.08
10.74
9.79
9.48

114

Oil
Coal
Consumption Consumption
(ml/kwh)
(kg/kwh)
13.72
0.828
14.22
0.824
6.89
0.784
6.23
0.791
3.04
0.769
3.49
0.745
3.21
0.744
3.90
0.762
3.56
0.714
1.39
0.699


3.1 Basic Information regarding Power Generation at Thermal Power Plant
Station
Thermal Power Plant burns fuels and uses the resultant heat to convert water in the
steam, which drive the turbo generator. The fuel may be ‘fossil’ (Coal, Oil or Natural
Gas) or it may be fissionable (uranium). Whichever fuel is used the object is same to
convert heat into mechanical energy into electricity by rotating a magnet inside a set
of windings.
Conventional power plants work on RANKINE CYCLE. The cycle may be split into
distinct operations:
Water is admitted to the boiler raised to boiling temperature and then
superheated.
The superheated steam is fed to a steam turbine where it does work on the
blades as it expends.
The expended steam is rejected o the condenser and the resultant condensate is
fed back to the boiler via feed heaters.
The turbine drives a generator, which is turn supplies electricity to the bus
bars.
3.2 Problem Formulation
In PTPS, Unit No. 7 having an output capacity of 250 MW is considered for energy
Auditing Process. Energy Audit has been done for evaluating the performance of
main Unit and also the performance of sub units like Boiler, Turbine and generator,
Condenser & Heater are calculated, and compared their performance at different
output loads. The main problems, which are highlighted in PTPS Unit No. 7 are:
Energy efficiency has to be improved to survive in Global Market.
To extend the life of units by 15 to 20 years
To restore original rated capacity of the units.
To improve Plant availability/ load factor.
To enhance operational efficiency and safety.
To remove ash pollution and to meet up environmental standards.
3.3 History of Unit 7th
The unit was commissioned on coal firing on 28-09-2004 & dedicated on commercial
run w.e.f. 29-12-2004. The some of the main achievements of Unit 7th are lined
below:
i.
Unit-7th generated 1977.9204 MU (PLF 90.32%) during 2006-2007 which is
the highest generation from this unit after its commissioning.
ii.
Monthly highest generation of Unit-7th remained 189.034 MU (PLF 101.63%)
during Jan.-2007, which is the highest during a month since commissioning of
this unit.
iii. %age Aux. Consumption of Unit-7th remained 8.44% during this FY. Earlier
lowest Aux. Consumption was 9.76% during 2004-2005
iv.
Specific coal consumption of Unit-7th remained 0.628 Kg/Kwh during this FY,
which is the lowest since its commissioning.

115


v.
vi.

The Heat Rate of Unit-7th remained 2507 Kcal/kwh, which is the lowest since
commissioning of the unit.
Unit-7th (250 MW) remained in continuous operation from 11-01-2007/2130
Hrs to 08-03-2007/1555 Hrs (55 Days 18 Hrs 25 Mts), which is the highest
continuous running since commissioning the Unit.

3.4 Data Collection
The data for the auditing purpose is collected from the experimental work. The
experimental work is done at different output loads [250 MW, 232 MW, 210 MW
respectively] and summarized in tables below. The Table 2, 3 and 4 shows the data of
thermal power plant at different loads of 250 MW, 232 MW, 210 MW respectively.
Sr.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

Table No.2 Data for Thermal Power Plant at Output load 250 MW
Pr.
Tem.
Flow
Enthalpy
Description
Condition
0
bar
C
T/Hr
KJ/Kg
Superheat
Steam Inlet HPT
150
540
782
3414.6
Steam
Steam Outlet HPT
Superheat
and
38
340
710
2574.6
Steam
Inlet Re-heater
Steam Outlet ReSuperheat
38
540
710
3414.6
heater and inlet IPT
Steam
Steam Outlet IPT
Superheat
8
340
630
2574.6
and inlet LPT
Steam
6th Extraction HPT Superheat
38
340
70
2574.6
and inlet HPH6
Steam
HPH6 Outlet and
Water
24
210
70
2028.6
Inlet HPH5
5th Extraction IPT
Superheat
18
430
46
2952.6
and Inlet HPH5
Steam
HPH5 Outlet and
Water
7
200
125
1986.6
Inlet Dearator
3rd Extraction IPT
Superheat
9
311
26
2452.8
and Inlet LPH3
Steam
Drip Outlet LPH3
Water
123
1663.2
and Inlet LPH2
2nd Extraction LPT Superheat
1.6
213
22
2041.2
and Inlet LPH2
Steam
Drip Outlet LPH2
Water
-0.6
125
1671.6
and Inlet LPH1
1st Extration LPT
Superheat
-1.8
98
28
1558.2
Inlet LPH1
Steam
Drip Outlet LPH1
and Inlet to HotWater
50
1356.6
well
Exhaust Steam
Superheat
0.09
45
530
1335.6
Outlet LPT
Steam
Condenser Outlet &
Water
0.1
36
530
1297.8
Inlet Hot-well
Condensed Steam
Inlet to LPH1

Water

11.8

116

50

652

1356.6

Energy
MW
741.73
507.77
673.43
450.56
50.06
39.45
37.73
68.98
17.71

12.47

12.12

196.63
191.06
245.69


18

19

20
21
22
23

24

25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

Condensate Outlet
LPH1 and
Inlet LPH2
Condensate Outlet
LPH2
and Inlet LPH3
Condensate Outlet
LPH3 and Inlet
Dearator
BFP Inlet
Condensate Inlet
HPH5
Condensate Outlet
HPH5 and Inlet
HPH6
Condensate Outlet
HPH6 and Inlet
Economizer
Feed Water Inlet
Drum
Steam Inlet LTSH
Steam Inlet Platen
SH
Steam Inlet Final
Super Heater
Flue Gas Inlet Reheater
Flue Gas Inlet Final
Super Heater
Flue Gas Inlet
Platen Super-heater
Flue Gas Inlet
LTSH
Flue Gas Inlet
Economizer
Flue Gas Inlet APH
Flue Gas To Stack
SA Inlet APH
SA Inlet Boiler
PA Inlet APH
PA Inlet Boiler
Coal Supply to
Boiler
Cold Water Inlet to
Condenser
Hot Water Outlet
From
Condenser

Water

11.8

72

652

Water

11.26

92

1449

262.43

652
1533

120

18.4

163

786

Water

188

167

786

Water

187

202

1848

403.48

435.58

472.26

2196.6
2637.6

479.59
575.88

1146.6

250.34

3406.2

743.69

652

Water

298.94
399.81

2163

9.8

1650.6
1831.2

1995

Water

277.64

786

Water

183

242

786

Water

174

250

786

Steam

160

355

786

Steam

786

Steam

145

538

786

Flue Gas

-22

740

880

Flue Gas

-19.2

650

880

Flue Gas

-0.1

1120

880

Flue Gas

-1.1

916

880

Flue Gas

-0.7

456

880

Flue Gas
Flue Gas
Air
Air
Air
Air

-1.8
0.15
250
250
800
700

296
149
295
290
36
278

880
880
880
900
150
150

4254.6 1040.01

120

Water

7

30

45000

Water

6

38

947.61

5850.6

1430.15

4993.8

1220.71

3061.8
2389.8
1772.4
2385.6
2364.6
1297.8
2314.2

748.44
584.17
433.25
583.15
591.15
54.08
96.43

1146.6
1272.6

38.22
15907.5
0

1306.2

Coal

3876.6

16327.5
0

45000

117


Table 3 Data of Thermal Power Plant at output load 232 MW
Sr.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

Description

Condition

Pr.
bar

Tem.
0
C

Flow
T/Hr

Enthalpy
KJ/Kg

Energy
MW

Steam Inlet HPT

Superheat
Steam

141

534

735

3389.4

692.01

Superheat
Steam

35

340

675

2574.6

482.74

33

533

675

3385.2

634.73

6

350

600

2616.6

436.11

34

330

60

2532.6

42.22

Water

20

205

60

2007.6

33.47

Superheat
Steam

15

420

40

2910.6

32.34

Water

6.5

171

100

1864.8

51.8

Superheat
Steam

8

303

20

2419.2

13.45

1.4

218

17

2062.2

9.73

Steam Outlet HPT
and
Inlet Re-heater
Steam Outlet Reheater and inlet IPT
Steam Outlet IPT and
inlet LPT
6th Extraction HPT
and inlet HPH6
HPH6 Outlet and
Inlet HPH5
5th Extraction IPT
and Inlet HPH5
HPH5 Outlet and
Inlet Dearator
3rd Extraction IPT
and Inlet LPH3
Drip Outlet LPH3 and
Inlet LPH2
2nd Extraction LPT
and Inlet LPH2
Inlet LPH1
1st Extraction LPT
Inlet LPH1
Inlet to Hot-well
Exhaust Steam Outlet
LPT
Condenser Outlet &
Inlet Hot-well
Condensed Steam
Inlet to LPH1
Condensate Outlet
LPH1 and
Inlet LPH2
Condensate Outlet
LPH2 and Inlet LPH3
Condensate Outlet
LPH3 and Inlet
Dearator
BFP Inlet
Condensate Inlet
HPH5
Condensate Outlet
HPH5and Inlet HPH6
Condensate Outlet
HPH6 and Inlet
Economizer
Feed Water Inlet
Drum
Steam Inlet LTSH
Steam Inlet Platen SH

Superheat
Steam
Superheat
Steam
Superheat
Steam

Water
Superheat
Steam
Water
Superheat
Steam

120
-1.5

Water

97

1650.6
23

47

1554

9.93

1344

Superheat
Steam

0.08

45

505

1335.6

187.36

Water

0.08

40

505

1314.6

184.41

Water

11

45

600

1335.6

222.6

Water

10.5

71

600

1444.8

240.8

Water

10

89

600

1520.4

253.41

Water

8.6

117

600

1638

273.01

Water

16

160

718

1818.6

362.7

Water

172

161

718

1822.8

363.54

Water

171

196

718

1969.8

392.87

Water

168

238

718

2146.2

428.04

Water

160

246

718

2179.8

434.74

Steam
Steam

156

351

718
718

2620.8

522.69

118

28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

Steam Inlet Final
Super Heater
Super Heater
Flue Gas Inlet Platen
Super-heater
Flue Gas Inlet LTSH
Flue Gas Inlet
Economizer
Flue Gas Inlet APH
Flue Gas To Stack
SA Inlet APH
SA Inlet Boiler
PA Inlet APH
PA Inlet Boiler
Coal Supply to Boiler
Cold Water Inlet to
Condenser
Hot Water Outlet
From
Condenser

Steam

141

532

718

3381

674.3

Flue Gas

-10

635

800

3813.6

847.46

Flue Gas

-7

620

800

3750.6

833.46

Flue Gas

-0.08

950

800

5136.6

1141.46

Flue Gas

-0.4

861

800

4762.8

1058.39

Flue Gas

-0.65

433

800

2965.2

658.93

Flue Gas
Flue Gas
Air
Air
Air
Air
Coal

-0.8
0.143
240
240
615
615

294
147
292
272
36.5
292

800
800
800
850
142
142
114

2381.4
1764
2373
2289
1299.9
2373

529.19
392
527.33
540.46
51.27
93.60

Water

6

30

40000

1272.6

14139.99

Water

5

37

40000

1302

14466.67

Table 4 Data of Thermal Power Plant at load 210 MW
Sr.
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14

Description

Condition

Steam Inlet HPT

Superheat
Steam

Steam Outlet HPT
and
Inlet Re-heater
Steam Outlet Reheater and inlet IPT
Steam Outlet IPT and
inlet LPT
6th Extraction HPT
and inlet HPH6
HPH6 Outlet and
Inlet HPH5
5th Extraction IPT
and Inlet HPH5
HPH5 Outlet and
Inlet Dearator
3rd Extraction IPT
and Inlet LPH3
Inlet LPH2
2nd Extraction LPT
and Inlet LPH2
Inlet LPH1
1st Extraction LPT
Inlet LPH1
Inlet to Hot-well

Superheat
Steam
Superheat
Steam
Superheat
Steam
Superheat
Steam
Water
Superheat
Steam
Water
Superheat
Steam

Pr.
bar
135

Tem.
0
C
530

Flow
T/Hr
685

Enthalpy
KJ/Kg
3372.6

Energy
MW
641.73

33

338

635

2566.2

452.65

32

530

635

3372.6

594.89

5

338

565

2566.2

402.75

32

328

48

2524.2

33.66

18

200

48

1986.6

26.49

12

412

26

2877.0

20.78

6

156

80

1801.8

40.04

7

295

16

2385.6

10.60

0.0

0.00

2007.6

8.37

1629.6

0.00

1545.6

7.73

1339.8

0.00

Water
Superheat
Steam

1.2

15

115

Water
Superheat
Steam

205

-1.2

95
46

Water

119

18

15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

Exhaust Steam Outlet
LPT
Condenser Outlet &
Inlet Hot-well
Condensed Steam
Inlet to LPH1
Condensate Outlet
LPH1 and
Inlet LPH2
Condensate Outlet
LPH2 and Inlet LPH3
Condensate Outlet
LPH3 and Inlet
Dearator
BFP Inlet
Condensate Inlet
HPH5
Condensate Outlet
HPH5and Inlet HPH6
Condensate Outlet
HPH6 and Inlet
Economizer
Feed Water Inlet
Drum
Steam Inlet LTSH
Steam Inlet Platen SH
Steam Inlet Final
Super Heater
Super Heater
Flue Gas Inlet Platen
Super-heater
Flue Gas Inlet LTSH
Flue Gas Inlet
Economizer
Flue Gas Inlet APH
Flue Gas To Stack
SA Inlet APH
SA Inlet Boiler
PA Inlet APH
PA Inlet Boiler
Coal Supply to Boiler
Cold Water Inlet to
Condenser
Hot Water Outlet
From Condenser

Superheat
Steam

475

1331.4

175.67

0.07

38

475

1306.2

172.35

10.5

43

550

1327.2

202.77

70

550

1440.6

220.09

9.5

87

550

1512

231.00

8.2

115

550

1629.6

248.97

15
166

158
159

650
650

1810.2
1814.4

326.84
327.60

165

190

650

1944.6

351.11

160

Water

44

10.5

Water

0.07

234

650

2129.4

384.48

154

244

650

2171.4

392.06

150

345

138

527

650
650
650

2595.6
0
3360

468.65
0.00
606.67

-8

610

760

3708.6

782.93

-6

600

760

3666.6

774.06

-0.06

900

760

4926.6

1040.06

-0.2
-0.58

840
423

760
760

4674.6
2923.2

986.86
617.12

-0.6
0.13
230
230
550
550

292
145
292
65
36
277

5

30

760
760
760
790
130
130
110
35000

2373
1755.6
2373
1419.6
1297.8
2310
0
1272.6

500.97
370.63
500.97
311.52
46.87
83.42
0.00
12372.50

4

36

35000

1297.8

12617.50

Water
Water
Water
Water
Water
Water
Water
Water
Steam
Steam
Steam
Flue Gas
Flue Gas
Flue Gas
Flue Gas
Flue Gas
Flue Gas
Flue Gas
Air
Air
Air
Air
Coal
Water
Water

Note: In Table 2,3 & 4, the value of energy is calculated from the formula given as:
Energy = Flow (Kg/Sec.) * Enthalpy (KJ/Kg)/1000
4.0 DATA ANALYSIS
In this step, the data, which is collected from Power Plant Unit No.7 & at
different output load, is analyzed. Firstly from the data of Thermal Power Plant
120


running at the load of 250MW or full output load given in Table 2 is considered for
the analysis purpose. The data analysis work is as below:
Step 1: Boiler Section
• Inlet in Boiler
(i) Coal Inlet [40]
= 120T/hr = 120 x 1000/3600
=33.33 Kg./Sec.
Calorific Value of Coal = 4860 K Cal/Kg
Therefore, Energy
= 4860 x 33.33 x 4.2/1000
= 680.33 MW
(ii) Reheated Steam Inlet Energy [2]
= 507.77 MW
(iii)Inlet from Economizer Steam Energy [24]
= 472.26 MW
Total Inlet = (i) + (ii) + (iii)
= 680.33 + 507.77 +472.26 = 1660.36 MW
• Outlet from Boiler
(iv) Steam Inlet HPT Energy [1]
= 741.73 MW
(v) Steam Outlet From Reheated Energy [3]
= 673.44 MW
(vi)Flue Gases = Generally not taken in considration
Total Outlet = (iv) + (v) + (vi)
= 741.73 + 673.44 + 0
= 1415.17 MW
Loss in Boiler = Inlet – Outlet
= 1660.36 – 1415.17
= 245.19 MW
Efficiency of Boiler
= 1415.17 x 100/ 1660.36 = 85.23 %
Step2: Section Turbine & Generator Section
(i) HPT Inlet [1]
= 741.73 MW
(ii) HPT Outlet [2] + Extraction HPT [5] = 507.77 + 50.06 = 557.83 MW
Net Energy at HPT = (i) - (ii) = 741.73 – 557.83
= 183.9 MW
(iii)
IPT Inlet [3]
= 673.44 MW
(iv) IPT Outlet [4] + Extraction IPT [7] = 450.55+37.73
= 488.28 MW
Net Energy at IPT
= (iii)- (iv) = 673.44 – 488.28
= 14.84 MW
(v)
LPT Inlet [4]
= 450.56 MW
(vi)
LPT Outlet [9] + Extraction LPT [11] + Inlet LPH [13] =17.71+12.47 +12.12
= 42.3 MW
Net Energy at LPT = (v) – (vi)
= 450.56 – 42.3
= 408.26 MW
Net Input at Turbine (HPT, IPT & LPT) = 183.9 + 14.84 + 408.26 = 607 MW
Efficiency of Turbo Generator
= 250 x 100/ 607
= 41.19 %
Step 3: Section Condenser:
Condenser Efficiency
= Actual Cooling Water Temp rise
Max Possible Temp. Rise
= Water Outlet Temp. [42]- Water temp. at Inlet to condenser [41] * 100
Exhaust Steam Temp. [15] – Water temp. at Inlet to condenser [41]
= 53.33 %

= (38 – 30) x100
45 – 30
Step 4: Section Heaters (LP & HP)
LPH1 Effectiveness
= T [18] – T [17]
T [13] – T [17]
LPH2 Effectiveness
= T [19] – T [18]
T [11] – T [18]
LPH3 Effectiveness
= T [20] – T [19]
T [9] – T [19]
HPH5 Effectiveness
= T [23] – T [22]
T [7] – T [22]
121

= 72 – 50
98-50
= 92 – 72
213-72
= 120-92
311-92
= 202-167
430-167

= 0.46
= 0.14
= 0.13
= 0.13


HPH6 Effectiveness
Overall Unit Efficiency

= T [24] – T [23]
= 242-202 = 0.29
T [05] – T [23]
340-202
= Output of Station x 100
Input of Station
=

Energy sent out (KW)
.
Fuel burnt (Kg) x Calorific value of fuel (K Cal/kg)
= 250 x 100
= 36.74%
680.33
Similarly, the data of plant running at output load of 232 MW & at 210 MW is
analyzed and the results are shown in Table 5.
Table 5 Analyze data for the plant running at 232 MW & 210 MW
Description
Inlet in Boiler
Outlet from Boiler
Loss in Boiler
Efficiency of Boiler
Section Turbine & Net Energy at HPT
Generator Section Net Energy at IPT
Net Energy at LPT
Net Input at Turbine
Efficiency of Turbo Generator
Section Condenser Condenser Efficiency
Section
Heaters LPH1 Effectiveness
(LP & HP)
LPH2 Effectiveness
LPH3 Effectiveness
HPH5 Effectiveness
HPH6 Effectiveness
Overall station efficiency
Boiler Section

At 232 MW
1557.23 MW
1326.74 MW
230.49 MW
85.20 %
167.05 MW
166.28 MW
403.08 MW
736.41 MW
31.50 %
46.67 %
0.50
0.12
0.13
0.13
0.31
35.89%

At 210 MW
1460.72 MW
1236.62 MW
224.1 MW
84.66 %
155.42 MW
171.36 MW
376.03 MW
702.81 MW
29.88 %
42.86 %
0.51
0.12
0.13
0.12
0.33
33.67%

Now, from the data calculated for analysis purpose above is used for finding the
problems and their recommendations. The above data is summarized in Table 6.
Table 6 Analyzed data for different parameters of the plant running at various load
S. No.
1
2
3
4
5
6
7
8
9
10

Description
Boiler Efficiency
Turbine & Generator Efficiency
Condenser Efficiency
Heater LPH1 Effectiveness
Heater HPH5 Effectiveness
Heater HPH6 Effectiveness
Overall Plant Efficiency
Coal Consumption

250MW
85.23%
41.19%
53.33%
0.46
0.14
0.13
0.13
0.29
36.74%
120 T/Hr

232MW
85.20%
31.51%
46.67%
0.50
0.12
0.13
0.13
0.31
35.89%
114 T/Hr

220 MW
84.66%
29.88%
42.86%
0.51
0.12
0.13
0.12
0.33
33.67%
110 T/Hr

On the data in Table 6, parato diagram is made, which is more helpful to find
the exact status of the plant. Figure 1 shows the Efficiencies comparison between the
122


various plant output levels in term of Boiler Efficiency, Turbine & Generator Efficiency
& Condenser Efficiency. Figure 2 & 3 shows the Effectiveness value for the heaters at various
output level & finally the Figure 4 shows the comparison between overall plant efficiency at
various output level.
Various efficiencies comparision for plant running at various
output values
90.00%

Efficiency Value

80.00%
70.00%
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
Boiler
Efficiency

Turbine &
Generator
Efficiency

Condenser
Efficiency

Efficiency

Figure 1 Parato Analysis for various efficiencies for plant running at various output
values
Heater Effectiveness values for various output values
0.6

0.4
0.3
0.2
0.1
Series1
Heater LPH3

Heater LPH2

0
Heater LPH1

Effrctiveness Value

0.5

Heaters Detail

Figure 2 Parato Analysis for Heaters Effectiveness Values
123

Series2
Series3


Heater Effectiveness value for Various Output Values of the
Plant
0.35
0.3

Effectiveness Value

0.25
0.2
0.15
0.1
0.05
0
Heater
HPH5

Heater
HPH6

Heaters Detail

Figure 3 Parato Analysis for Heaters Effectiveness Values

Plant Efficiency in
(%age)

Overall Plant Efficiency at Various Output Level
37.00%
36.50%
36.00%
35.50%
35.00%
34.50%
34.00%
33.50%
33.00%
32.50%
32.00%
At
250MW

At 232
MW

At210
MW

Plant Output Detai l

Figure 4 Parato Analysis for Overall Plant Efficiency

5.0 RESULTS & RECOMMENDATIONS
From the analysis part of this work, it is concluded that the overall plant
efficiency varies with the variation or small change in the output loads. From the
experimental work done in above steps shows that as the output load is lower the
124


efficiency of total unit is low. Output Load of the plant always depends upon the
requirements for consumption of energy. As the energy consumption decreases, Plant
has to be starting to run at lower load and the overall performance is also lower,
because energy cannot be stored. On the other hand if the Plant or Unit can run at Full
Output Load or 250 MW load the performance is higher. Some of the
recommendations based on this research work are made for increasing the
performance of the plant is shown in Table 7.
Table 7 Recommendation for increasing Plant Efficiency
Description
Recommendation

Boiler
Section

Condenser

Overall
Plant
Efficiency

Boiler Efficiency
can increased upto
90 % to 95 %

Low
condenser
vacuum due to:(a) Air ingress in
the condenser.
(b) Dirty tubes.
(c)
Inadequate
flows
of
Condensate
Water
in
condenser.
Overall efficiency of
plant can be
increased

1. By increasing the oxygen content of the
coal, result in reduced level of heating
valve
2. Boiler efficiency is mainly attributed to dry
flue gas, wet gas & sensible heat loss so
that by reducing the flue gas exhaust
temperature.
3. Periodic maintenance of boiler like:
(a) Periodical cleaning of boiler.
(b) Proper water treatment
programmes and blow down control.
(c) Excess air control.
(d) Percentage loading of boiler.
(e) Steam generation pr. and
temperature.
(f) Boiler insulation
(g) Quality of fuel.
(i) Cooling Water flow must be checked
for correct quantity.
(ii) Condenser tubes must be cleaned
regularly.
(iii) Vacuum drop must be cleaned
regularly. CW pumps impeller must be
checked for erosion.
(iv) Air ingress must be arrested.
(v) Improvement in quality of cooling water
and close cycle.

By using wash-coal, which will save the
energy from waste with ash.

6.0 REFERENCES & BIBLIOGRAPHY
1. Raask, E Lo, K.L. & Song E, Z. M.(1969), “Tube Failures Occurring in the
primary super heaters and reheaters and in the economizers of coal fired boilers”,
Energy Conservation in Coal fired boilers , Vol.12, 1969, Page No. 185.
2. Rajan G.G. (2001), “Optimizing Energy efficiency in industries by Energy Loss
Control-models”, Chapter-14, Page No. 276.

125


3. Pilat, J., Micheel P. A. (1969) “Source test Cascade impactor for measuring the
size ducts in boilers”, Energy Conservation in Coal fired boilers, Vol. 10, Page
No.410-418.
4. Schulz, E., Worell, E. & Blok, K. (1974) “Size distribution of submission
particulars emitted from Pulverized coal fired plant” Energy Conservation in
Coal Fired boilers, Vol. 10, Page No.74-80.
5. Neal, P.W.Lo, K.L. (1980) “Conventional automatic control of boiler outlet
steam pressure” Energy Conservation in Coal fired boilers, Vol. 16, Page No.
91-98.
6. Dognlin, Chen James, D & Varies B.de (2001), “Review of current combustion,
technologies for burning pulverized coal”, Energy conservation in coal fired
boilers Vol.48, Page No. 121-131.
7. Bergander, Mark J. Porter, R.W. (2003), “ Most troublesome component of
electric power generation plant”, Energy conservation in coal fired boilers, Vol.
32, Page No. 142-149.
8. Hatt, Roderick, M. & Lewis, W (2003), “Coal ash deposits in coal fired boilers”
Energy conservation of coal fired boilers, Vol. 14, Page No. 181-189.
9. Central Electricity Generating Board, “Modern Power Station Practice
(Operation & Efficiency),” Pergamon Press Oxford, New York. 2nd Edition,
Volume-7.
10. P.K.Nag “Power Plant Engineering” Tata McGraw-Hill Publishing Company
Limited New Delhi. 2nd Edition.

126

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