I have attached this report where we find out the actual reason steam turbine Deaerating Condenser Performance degradation which was written on June 06, 2012.That time I was in Haripur Power Limited (HPL) ,A 360 MW CCPP of Pendekar Energy Bangladesh Ltd. The report outcome showed that the Steam turbine load could be reached to its maximum capacity after those valve maintenance works on the next Steam Turbine Major inspection on 2013.We hope we can increase our steam turbine load to 5-7 MW/D on that time. The operational guys were indicating Circulating water pumps (CWP A&B) were not performing to its design capacity & Ejectors/vacuum pumps are not performing well.So,Mechanical Maintenance Team (MMT) team find this successful outcome after several study. Condenser vacuum condition has improved a lot after maintenance of the valves on last Major Inspection on 2013. It is a sample report where we can realize that identifying actual reason for an equipment performance is not only a job of operational people but also a responsibility of the maintenance guys.

1. Deaerating Condenser Performance
Improvement Report
June 06, 2012
Prepared by
Ashik Ahmed
Maintenance Engineer
In a Multinational Power Plant
Email: ashik_rofy@yahoo.com,ashik.rofy@gmail.com
Mobile: +880-173-0059920
LP Cylinder
Exhaust Hood
Neck
Transition Piece
Shell
Tube Bundle
Air Extraction Points
Page
Hot well
1
Water box division

2. THE STEAM TURBINE SPECIFICATION:REACTION REHEAT CONDENSING TYPE TWO CASING DOUBLE FLOW EXHAUST
RATED OUTPUT 131,600 KW
RATED SPEED 3,000 RPM
MAIN STEAM PRESSURE 100 BAR A
MAIN STEAM TEMPERATURE 565 ºC
REHEAT STEAM PRESSURE 29.9 BAR A
REHEAT STEAM TEMP. 565 ºC
EXHAUST PRESSURE 0.060 BAR A
MANUFACTURER: FUJI ELECTRIC
PROBLEM:Absolute Pressure of Condenser Vacuum remains -697.24 (mmHg) but the value was
-705 (mmHg) in few years back. So, the Steam turbine load can’t be operated to its maximum
capacity.
In the same time the water temperature Difference Between inlet & Outlet on Water Box-B
Side shows ~2°c whereas temperature Diff. Between inlet & Outlet on Water Box-A Side shows
~5.4°c.The temperature difference should be quite near as they are handling the same
condensate steam from Steam Turbine.
POSSIBLE REASONS:Air Leakage
Circulating water pumps (CWP) are not performing to its design capacity.
Ejectors/vacuum pumps are not performing well
Some extra steam load on condenser water box-A side cause the ∆T is extremely higher.
Page
3
*** At first let we all try to understand what a Deaerating condenser. Some portions of next III pages
are collected from a presentation of an unknown author (Probably a presentation of the former owner
of this plant AES; during their commissioning time in Bangladesh).As it is very important for our
understanding; I have included some portion (Literatures) of that presentation in to this report. ***

3. WHAT ARE FUNCTIONS OF DEAERATING CONDENSER?
Provide a heat sink within which to condense, and so recycle, the high quality feedwater
allow increased heat/work transfer across the steam turbine by reducing the LP Turbine exhaust
steam conditions
Remove dissolved oxygen and non -condensable gases from the steam /condensate
COMPONENTS OF THE CONDENSER
The condenser is a single pressure, two pass, vertically divided water box design with its entire
condensing surface (8,806 m2) in a single rectangular shell.
Cooling Water, supplied from the Main Cooling Water System flows (CWP Maker:KSB) through the
condenser tubes.
Steam, expanded in the steam turbine, exhausts into the neck of the condenser through exhaust
openings located after the final stages of the LP cylinder/Turbine.
The steam then flows through the transition piece to the tube bundles located lower in the shell.
Cooling water flows through the tube bundles. Steam cooled and condensed on the outside of the
condenser tubes falls to the hot well located at the bottom of the condenser. The condensate is
returned to the Steam/water cycle by the condensate extraction pumps (CEP Maker:KSB).
The condensing steam reduces significantly in volume creating a reduced pressure in the condenser.
The degree of negative pressure is dependent on the cooling water temperature which in turn affects
the steam vapor pressure and temperature.
Excess air is removed from the condenser steam space initially by the condenser vacuum pumps and
any subsequent air and non condensable gases migrating into the condenser are removed by these
pumps
LP
Cylinder
Exhaust Hood
Neck
Transition Piece
Shell
Tube Bundle
Air Extraction
Points
Hot well
FIGURE 1
SIMPLIFIED DIAGRAM OF CONDENSER SHOWING TWO PASS
Page
3
Water box
division

4. CONNECTIONS TO THE CONDENSER
The following connections are made to the Condenser through the condenser flash box.













Cold Reheat Steam Dump Line
HP Connection Pipe Drains
MCV Downstream Drains
ICV Upstream Drains
HP/IP Outer Casing Drains
HP/IP Inner Casing Drain
HP/IP Balance Pipe Drain
HP Front Gland Drain
Turbine Gland Steam Header Drain
LP Admission Steam Pipe Drain
ACV Drain
CRH Steam Check Valve Front Drain
Flash Tank Drain
It can be seen that all the turbine drains taken to the flash box are from a point downstream of the
main HP, IP and LP Steam Isolating Valves.
COOLING WATER CIRCUIT
The cooling water circuit provides the heat exchange medium within the condenser. River Water is
pumped through the condenser tubes by cooling water pump (CWP). Steam condenses on the outside
of the tubes.
The cooling water flow through the condenser produces a syphonic effect once the pipe work is fully
charged with water; this in turn causes a negative pressure to appear at the outlet water boxes. The
condenser cooling water outlet conduit is taken to a seal pit, which provides a fixed atmospheric
breakpoint in the system. This ensures that during normal operation the pressure at the outlet water
boxes, although negative, will remain above the vaporization pressure associated with the outlet
temperature of the cooling water.
Page
4
The Inlet, Return and Outlet Water boxes of the condenser are divided into two separate sections.
Each section is served by independent inlet and outlet isolating valves. As a two pass circuit the water
flows into the bottom or inlet water boxes, passes through a nest or bundle of tubes (lower quadrants)
to the reversal or return water boxes, where it reverses direction and rises to the upper quadrants of
the condenser before flowing through a second tube bundle to the outlet water boxes.

5. Exhaust Steam from LP Turbine
Upper Quadrants-Outlet
Hot Water
Send back to
River after
proper Heat
Transfer
Lower Quadrants-Inlet
DEAERATING
CONDENSER
CWP
-A
CWP
-B
Relatively Cold water taken From
River
FIGURE 2
COOLING WATER CIRCUIT
CONDENSER PERFORMANCE DEPENDS ON FOLLOWING PARAMETER MONITORING:During normal operation regular checks of the following parameters should be made and the values
logged:





STG Load
Air Leakage
Inlet Cooling Water Temperature
Outlet Cooling Water Temperature
Absolute Pressure in Condenser ( Condenser Vacuum)
The following values should be calculated and logged:
Page
The Cooling Water Temperature Rise is calculated from the difference between Cooling Water Outlet
and Inlet Temperatures.
The Initial Temperature Difference is calculated by first determining the steam saturation
temperature for the current Condenser Pressure and the subtracting the Cooling Water Inlet
Temperature.
5
The Cooling Water Temperature Rise
Initial Temperature Difference
Terminal Temperature Difference

6. NOW WE WILL TRY TO FIND OUT THE POSSIBLE SOLUTION FOR
CONDENSER VACUUM PROBLEM & SEVERE TEMPERATURE DIFFERENCE
BETWEEN WATER BOX A & B.
HISTORY OF
CONDENSER
 The Ejector erection was completed, commissioned and kept on operation on 14.08.04. 1st time both
the ejector & vacuum pumps operation had started on 15.03.08.
 Before that the condenser vacuum was maintained with either vacuum pump or ejector.
 All vacuum pumps & ejector are in operation from 21.03.11 to till date.
 The temperature difference between cooling water in/out on water box A & B had started from 07.10.11.
CONDENSER DETAILS:
DEAERATING CONDENSER
Code: HEI (Ninth Edition)
Heat Duty 799.1´106 KJ/h
Empty Weight 165000
P.O. No. HAC-0004M-´-30466
Surface Area - 8806 m²
Hot well Capacity- 35.3 m³
Operating Weight- 310 000 kg
Mfg. Serial No.HE-00-026
Shell side
Design Pressure 1.013 / F.V bar. A
Design Temp.36.18 / 36.18 ºC
Fluid: Steam
Flow Rate :
357500 kg/h
Hydro Test: Full of Water
Tube side
3.5 / F.V bar. A
25 / 30.49 ºC
River Water
34680000kg/h
5.25
Page
 Extra loading to the condenser.(Valve passing)
 Air ingression to the condenser.
 Performance degradation of CWP pump.
 Performance degradation of Ejector & vacuum pumps.
 Temperature difference between condenser A & B side.
i) Extra loading to the condenser.(Valve passing)
Case:-I)
The IP bypass stop valve HV-336B & PCV-336B has got huge
passing.
The IP bypass line PCV 336B was found passing on the last CI2012.Continuous condensate was found on that line. The line
ends over the tubes of condenser A side.
The condensate pressure was 4 bar that time, while
on normal running condition the R/H outlet pressure
is over 28 bar.
The condenser inlet temperature (TE-336C) was found 196˚c
on normal running condition.
The temperature reduced to 150˚c while stopping the stop
valve HV-336.But the stop valve also got passing that’s why the
temperature didn’t come down.
6
Condenser Performance Degradation probable cause:

7. Case:-II)
HIP turbine drain valve 045A,045B.045D & 045 I was showing huge passing .The temperature on the
downstream of this valves was observed (139.4°c ,245.3°c ,282.3°c & 504.2°c ).Whereas the other valves are
having temp <45°c .
This passing high temperature steams goes to the flash box, ultimately raising the temperature of the
condenser water box.
Case:-III)
The drain valves of MOV-320c have got huge passing. The CEP discharge to the flash tank TCV-033E got 93%
opening. Later on after closing the upstream isolation valve of MOV-320c,the TCV-033E Opening reduced to
43%.
Case:-IV)
The MOV-020(A, B, C &D) the HP SPR HTR & R/H outlet drain to the flash tank got some passing too. As the
flash tank cep discharge TCV-033E opening also reduced a bit after closing the upper isolation valves.
ii) Air Ingression to the Condenser
The Crack over the IP Bypass line near spray water injection
point could be checked again.
The blind flange of condenser shell side shows loose bolts.
All other line flange could be inspected through soap bubble test
for finding air ingression.
Page
7
III) Performance degradation of CWP pump.

8. We can see from the technical data sheet that the flow will be increased on the increase of water level.
CIRCULATING WATER PUMP:-
CIRCULATING WATER PUMP MOTOR –
Hyundai
Made:- Hyundai
3 Phase induction motor,
Model 1350VKNM
Type: HLA7 902-36Y
Serial No.KA0366-CWP-001
1100 KW, 12P, 6600 V 134.7 Amp
Tag No. CW-M-PP-03-1
494 RPM, Efficiency : 94%
Capacity 18,600 cu.m/hr.
CosΦ :0.76
Total head 16m
HPL overall, P.F, CosΦ =0.80
Design temp. 25 ºC
Power (Bhp) 1100 Kw
Speed 493 rpm
CALCULATION:Date : 18.06.12
Given:CWP-A
Current :- 109 A, Dish. Pr: 1.02Bar ,
Inside Water Level:- 7120 mm,Voltage: 6600 v
Motor efficiency: 94%
Assuming Pump efficiency on 85 %
Assuming frictional loss =2 feet
HPL overall, P.F, CosΦ =0.80
So, Motor Power = √3 x V x I x CosΦ
=1.732 x 6600 x 114 x 0.80 = 104.25 KW
So ,the Bhp = Motor Power x Efficiency of motor /0.746 =104.25 x 0.94/0.746
=1313.637 Hp
The head of the pump,(feet)= pump discharge pressure (in abs) ± Suction head + friction loss
H =(1.01325+1.09) x 14.7 x 2.31/specific gravity – (7.12-1.1) x 3.28+ 2
= 71.45 – 19.74+ 2
= 53.71 Feet
We know
Flow,Q= 3960 x ή x BHP
H
3960 x 0.85 x 1313.637
53.71
= 82325.67 gal/min
Or,we know
Flow,Q= 550 x ή x BHP
γH
550 x.85 x 1313.637
62.4 x 53.71
=183.238 feet3/sec
= 18679.4 m3/hr
=18698.19 m3/hr
Page
8
The Cooling Water Pump flow is found up to the requirement; so can omit this from our cause list.

9.  iv) Performance degradation of Ejector & vacuum pumps.
We can see from the cooling water inlet temperature the vaccum will be 696 mmhg at cooling water inlet temp
32°c.
Absolute pressure = atm pressure+ gauge pr.
So, 0.085 bara= 1.01325 + gauge pr.
Gauge pressure = 0.085 - 1.01325
= - 0.92825 bar = - 696mmHg
We found the same vacuum on 16.06.10.So the ejectors & vacuum pumps are performing well.

v) Temperature difference between water box A & b
Page
**PLEASE SEE THE WATER BOX A & B INLET & OUTLET DATA ON NEXT PAGES FOR YOUR
BETTER UNDERSTANDING.**
9
The condenser tube cleaning was done on CI-2012 & there was no significant variations on tubes were observed
that time. So, either extra load is on A side or the circulating water is flowing less on water box A side.
As the IP bypass line is just over the condenser water box A side, so there is a huge possibility of temperature
increase.

10. Several Data were taken on 5th & 6th Feb'12 on various discharge valve opening position due to Temperature Varience on Condeser Box A & B..
They are as follows:Condenser A Side
Serial
No
Date
Time
Cooling
Water
Inlet
Temp°C
(A Side)
TE-048A
Cooling
Water
Outlet
Temp°C
(A Side)
TE-048F
Temp
Differ °C
(OutletInlet
5.8
5.6
5.7
5.3
5.5
5.8
7.1
6.9
7.2
1
2
3
4
5
6
7
8
9
10
12:44:11
12:48:43
12:49:00
05.02.12
14:24:28
14:28:26
14:30:20
5:26:27
6:26:03
06.02.12 7:25:40
13:42:32
22.2
22.2
22.2
22.3
22.3
22.3
22.2
22.2
22.2
22.5
28
27.8
27.9
27.6
27.8
28.1
29.3
29.1
29.4
28.5
11
15:04:24
22.6
29.1
Condenser B Side
Pressure
PT-048CA
(Bar)
Discharge
Valve
Opening
%
Cooling
Water
Inlet
Temp°C
(B Side)
TE-048B
Cooling
Water
Outlet
Temp°C
(B Side)
TE-048G
25.1
25.2
25.3
26.6
26.3
26
27.3
27.9
26.7
58.2
58.2
58.2
58.3
58.3
40.6
6
0.72
0.78
0.79
0.76
0.71
0.77
0.71
0.79
0.8
0.71
62.7
62.8
43.4
62.4
22.4
22.4
22.5
22.6
22.7
22.6
22.4
22.3
22.4
22.7
6.5
0.91
37.5
22.9
Discharge
Valve
Opening
%
Seal
Well
Temp°C
Vacuum
mmHg
(─)
GTG
Load
MW
STG
Load
MW
Total
Load
MW
0.72
0.82
0.83
0.79
0.72
0.76
0.71
0.81
0.8
0.72
58.2
39.3
39.3
39.2
58.5
58.5
24.5
24.8
24.5
24.9
25.1
25
31.6
31.7
30.8
694.5
694.3
694.4
693.8
693.9
693.8
702.6
702.8
702.3
693.1
81.1
81.3
81.5
81
81.8
81
125.3
125.6
110.6
76.6
229.4
228.9
231.2
229.6
230.3
228.8
380.6
384.5
329.6
25.1
148.3
147.6
149.7
148.6
148.5
147.8
255.3
258.9
219
135.7
0.92
39.8
26.3
693.3
136.4
76.6
213
Temp
Differ °C
(OutletInlet)
Pressure
PT-048CB
(Bar)
26.6
2.7
2.8
2.8
4
3.6
3.4
4.9
5.6
4.3
3.9
27.1
4.2
61.9
44.2
61.7
61.6
212.3
At 6th Feb 15:04 pm the vent line was open on both sides. The discharge valve was opened slowly & until water came out from the vent lines. Water didn't come from (048BA) discharge A side vent
even on 37.5 % opening. As the CWP-A vibration was too high (Near 8.9 mm/s) ,the discharge valve didn't close more. Water came on rest of the valves:- I) Suction vent line of A side (048CA),II)
Suction vent line of B side (048CB) & III) discharge vent line of B side (048DB).
It is seen from the data that when the ST load is above (110~125 MW) or Total load is above (329~380MW) the seal well temperature became higher than the cooling water return
temperatures (After the Condenser).Theoretically it is not possible until unless the following causes:● The thermocouples of return line (TE-048F & TE-048G) not functioning properly above 30°C OR
● Any underground pipe line near seal wall OR
● Any other operation causes.
Remarks:The cooling water return temperature of Water box-A is higher than Water Box-B.
As water is not coming even closing the water box-A discharge valve near 30% opening So, Top tubes of Condenser – A side is not getting water.
►As the cleaning will be carried out on Outage 2012, the answers could be found after inspecting the scale formation on the Water Box –A side top tubes.
►It could be assumed that the scale formation on Condenser water box-A is higher then the B side.
►As well as the opening of suction & discharge valves of the Condenser water box could be checked on the outage.
►Any steam leakage on A side where the The condenser inlet of IP bypass just above the tube bundles.

11. Steam Turbine Condenser Vacuum Several Years Data on Several Steam turbine load
& cooling water inlet & outlet temperature
Water
Water Box Water Box Box A
Inlet Pr.A Outlet Pr.B Inlet
Bar
Bar
Temp.
°c
Water
Box A
Outlet
Temp
°c .
Date
Ejector
Vacuum
Pump
Ambient
Temp
Condenser
Vacuum
(mmHg)
PT-032A
14.08.04
05.04.06
07.05.06
10.06.06
17.07.06
20.12.06
25.01.07
28.04.07(N)
01.08.07
16.12.07
16.01.08
24.02.08
14.03.08
In Service
Isolated
In Service
In Service
In Service
In Service
In Service
In Service
Isolated
Isolated
Isolated
Isolated
Isolated
In Service
Isolated
Isolated
Isolated
Isolated
Isolated
Isolated
In Service
In Service (A, B & C)
In Service (A& B)
In Service (B)
27
23
26
31
20
16
27
28
20
20
21
28
-694.6
-690.1
-703.9
-698
-706.5
-721.8
-690.4
-699
-709
-696
-707
-705
231.5/53.0/350.5
245.1/46.6/361.3
248.1/45.5/308.3
237.8/50.3/375.3
249/55/337
257.4/52.1/340.1
226/55.7/384.5
247/46/359
241/31/328
233/42/325
252.8/53.6/355.1
227.6/41.4/316.2
15.03.08
In Service
In Service (B)
28
-705
251.6/45.5/335.9
114
41.8
0.86
0.88
27.2
31.03.08
17.07.08
23.11.08
23 11 08
24.11.08
09.12.08
10.12.08
12.12.08
31.12.08
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service (B)
In Service (B)
In Service (C)
In Service (A & C)
Isolated
In Service (A, B & C)
Isolated
Isolated
28
31
21
21
21
21
22
18
-697
-702.8
-692
692
-687
-706
-692
-699.3
-709.2
262/48.9/326
251.3/46.9/317.4
247/54/343
230/43/318
198/50/277
214/68/359
257.3/39.3/321.4
240.5/43.8/350
122
123
125
108
93
105
118
120
43.8
41.9
43
44.2
38.1
43.2
40.6
38.3
0.78
0.83
0.69
0 69
0.5
0.68
0.69
0.74
0.66
0.79
0.85
0.7
07
0.51
0.69
0.69
0.74
0.67
30
29
27
27
27
26.9
27.1
23.5
36.3
35
33
35
30
29
32.2
28.5
19.04.09(D)
In Service
Isolated
30.8
-684.3
270.2/48.8/365.3
120
45.7
0.61
0.62
33.4
19.04.09(N)
20.04.09(D)
20.04.09(N)
In Service
In Service
In Service
In Service (A, B & C)
In Service (A & C)
In Service (A, B & C)
29.9
31.1
29
-685
-683.8
-685
233/43/313
224/48.2/354.7
233/43/313
106
122
116
45.2
45.9
45.2
0.54
0.58
0.54
0.58
0.59
0.58
18.01.10
In Service
In Service (A)
13.4
-712.3
252/51/340
127
35.8
0.68
04.04.10
21.08.10
23.12.10
19.03.11
21.03.11
30.07.11
27.09.11
05.10.11
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service (A & C)
In Service (B)
In Service (C)
In Service (A & B)
In Service (A, B & C)
In Service (A, B & C)
In Service (A, B & C)
In Service (A, B & C)
29.3
29.7
17.2
27
27.3
30.4
21.9
26.6
-693.5
-692.1
-706
-700
-699.2
-695
-690
-685.6
267/47/352
260/52/364
242.0/53.4/321.0
247/49/138
271.3/52.0/337.7
246/49/340
245/53/371
245.2/48.6/319.4
260/49/54
242.8/46.8/53.8
122
124
117
119
122
119
123
112
42.7
42.9
38.1
40.5
40.7
43.6
44
44.7
07.10.11
In Service
In Service (A, B & C)
31.5
-682.9
257.3/49.8/337.9
258.9/46.4/52.3
121
17.10.11
In Service
In Service (A, B & C)
28
-676.5
222/42/306
224/42/49
19.10.11
In Service
In Service (A, B & C)
27.8
-680.9
182/38/292
23.10.11
In Service
In Service (A, B & C)
26.5
-689.1
25.12.11
In Service
In Service (A, B & C)
13.1
-704.6
Water
Box B
Inlet
Temp.
°c
Water
Box B
Outlet
Temp.
°c
33.6
HP/IP/LP Feed
Water Flow
(Ton/hr)
HP/IP/LP Feed
Steam Flow
(Ton/hr)
S/T Load
MW
Condenser
Temp
TE(033EA)
°c
Ejector erection completed, commissioned and kept on operation. All outage preparation done.
116
43.7
0.71
0.7
30.6
35.7
30.7
118
45.7
0.74
0.75
32.2
36.3
32.3
119
41.4
0.74
0.75
28.9
33.3
28.9
120
43.2
0.78
0.8
30.4
34.8
30.5
123
40.1
0.74
0.76
25.9
31.6
25.9
122
35.8
0.71
0.72
20.9
26.5
21.3
123
44.1
0.79
0.82
30.4
35.6
30.4
121
40.4
0.72
0.74
27.6
32.6
27.5
121
39.3
0.69
0.7
24.1
29
0
115
41.4
0.86
0.88
22.8
29.8
0
126
38.9
0.66
0.63
22.4
25
0
110
41.5
0.78
0.79
27.3
33.3
5.1
4.1
4.4
4.4
5.7
5.6
5.2
5
4.9
7
2.6
6
5
5.2
2.4
3.9
4.8
4.8
5
3.3
0
0
0
0
6.4
0
6.3
6
6
8
3
2.1
5.1
5
38.1
4.7
0
34
33.4
34
38
38.2
38
4
4.8
4
0
0
0
0.69
21.2
26.9
5.7
0
0.68
0.69
0.71
0.67
0.68
0.72
0.72
0.77
0.69
0.7
0.72
0.68
0.69
0.74
0.74
0.8
30.7
30.3
22.8
25.4
25.6
31.1
30
31.7
35.3
35.2
27.9
29.7
29.2
34.8
35.62
36.8
30.34
31.65
34.67
36
4.6
4.9
5.1
4.3
3.6
3.7
5.62
5.1
0
0
0
0
0
0
4.33
4.35
45.8
0.72
0.74
31.51
36.56
31.39
34
5.05
2.61
100
48
0.77
0.79
31.27
36.09
31.39
34.01
4.82
2.62
203/232/45
89
46
0.69
0.7
30.58
35.8
31.39
34.01
5.22
2.62
207/42/292
212/39/46
95
44
0.7
0.71
30.4
36.19
30.53
32.21
5.79
1.68
193/42/291
214/231/46
100
38.9
0.78
0.8
22.1
28.2
6.1
0
Remarks
0
6
0
0
0
0
0
0
29
35.7
37.5
31.3
34.4
30.7
26.1
35.4
30.8
0
0
0
Condens
er IP By
Diff. Betn Diff. Betn
pass line
inlet &
inlet &
Inlet
Outlet on Outlet on
Temp
A Side
B Side
(TE°c
°c
336C)
°c
35
rom the
1st time both the ejector & vacuum pumps are
in operation
ST gland steam pressure is high
probably due to the passing
through pressure control valve.
Ejector air valve and steam line
has been closed due to
vacuum fall in low load.
The temperature difference between cooling
water in/out on water box A & B has started
the leakage steam were coming
out from the upper side of welding joint crack
and the joint is up of the Spray hose.
Crack IP Bypass line near spray
water injection point has been
repaired by welding.
IP by-pass PCV was opened to 10%
to check vacuum and condenser
temperature difference.
But no vacuum was increased.

12. Date
Ejector
Vacuum
Pump
Ambient
Temp
Condenser
Vacuum
(mmHg)
PT-032A
22.02.12
19.03.12
In Service
In Service
In Service (A, B & C)
In Service (A, B & C)
19.9
26.3
-698.5
-694.5
255/51/386
192/39/269
20.03.12
In Service
In Service (A, B & C)
27.6
-685.6
21.03.12
In Service
In Service (A, B & C)
25.9
27.03.12
25.04.12
11.05.12
05.06.12
10.03.12
10.06.12
11.06.12
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
In Service
(A, B & C)
(A, B & C)
(A, B & C)
(A, B & C)
(A, B & C)
(A, B & C)
(A, B & C)
12.06.12
In Service
12.06.12
12.06.12
12.06.12
Water
Water Box Water Box Box A
Inlet Pr.A Outlet Pr.B Inlet
Bar
Bar
Temp.
°c
Water
Box A
Outlet
Temp
°c .
Water
Box B
Inlet
Temp.
°c
Water
Box B
Outlet
Temp.
°c
24.5
30
S/T Load
MW
Condenser
Temp
TE(033EA)
°c
197/211/42
123
89
41.4
42.1
0.69
0.65
0.71
0.68
24.5
27.8
27
32.8
194/40/281
197/211/42
87
44.4
0.69
0.7
28
-685
203/42/256
204/38/45
91
44.2
0.68
0.72
28.7
31.9
31.8
24.1
30.3
32.4
33.1
-696.2
-689.6
-683.9
-685.4
-691.51
-693
-692.1
228/53/358
186.6/45.7/340.9
251.1/50.1/338.9
235.2/46.5/336.9
258/48/321
240/51/356
243.0/48.4/320.1
258/275/51
121
102
117
111
120
117
117
43.5
44.3
44.9
44.8
46.1
45.3
46.3
0.68
0.67
0.69
0.74
0.64
0.65
0.66
In Service (A, B & C)
33.19
-691.3
119.1
46
In Service
In Service (A, B & C)
35.59
-698.9
119.6
In Service
In Service (A, B & C)
36.9
-700.4
112
In Service
In Service (A, B & C)
36.8
-701.2
117
14.06.12
In Service
In Service (A, B & C)
32.41
-691.27
120.56
14.06.12
In Service
In Service (A, B & C)
36.3
-688.044
116.36
14.06.12
In Service
In Service (A, B & C)
36.16
-688.79
118.32
46.86
HP/IP/LP Feed
Water Flow
(Ton/hr)
HP/IP/LP Feed
Steam Flow
(Ton/hr)
256/48/52
252.6/45.1/255
Condens
er IP By
Diff. Betn Diff. Betn
pass line
inlet &
inlet &
Inlet
Outlet on Outlet on
Temp
A Side
B Side
(TE°c
°c
336C)
°c
2.5
5
5.5
0
32.1
4.1
0
28
32.6
4.6
0
0.72
0.7
0.71
0.76
0.66
0.68
0.685
29.3
31.3
31.6
31.4
32.7
31.6
32.9
35.4
36.6
37.2
37
38.1
36.8
38.1
6.1
5.3
5.6
5.6
5.4
5.2
5.2
0
0
0
0
0
0
0
0.63
0.66
32.5
37.9
32.8
34.8
5.4
2
194.56
45.7
0.65
0.68
32.2
37.6
32.4
34.6
5.4
2.2
191.36
45.5
0.62
0.65
32.3
37.6
32.5
34.3
5.3
1.8
187.12
46.1
0.65
0.67
32.7
38.1
32.8
34.8
5.4
2
186.16
45.92
32.65
38.09
32.79
34.7
5.44
1.91
192.2
46.36
33.09
38.59
33.44
35.28
5.5
1.84
188
33.25
38.63
33.38
35.38
5.38
2
45
Ejector HP/IP nozzle replacement
work is going on.
Ejector put back in service after HP & IP
nozzles replacement.
Vacuum was increased from 684.3 mmHg to -692.5 mmHg &
ST load from 90 MW to 91.6 MW.
14.06.12
In Service
In Service (A, B & C)
30.74
-689.38
119.5
46.89
33.54
38.77
33.81
35.81
5.23
2
196
16.06.12
In Service
In Service (A, B & C)
26.51
-695
120.79
46
32.46
37.87
32.61
34.64
5.41
2.03
196
16.06.12
In Service
In Service (A, B & C)
26.06
-697
121.51
45.63
31.75
37.21
31.84
34.12
5.46
2.28
192
16.06.12
In Service
In Service (A, B & C)
26.52
-696.97
121.58
45.45
31.68
37.17
31.9
33.96
5.49
2.06
165
16.06.12
In Service
In Service (A, B & C)
26.52
-696.97
121.58
45.45
31.68
37.17
31.9
33.96
5.49
2.06
160
16.06.12
In Service
In Service (A, B & C)
25.66
16.06.12
In Service
In Service (A, B & C)
26.52
12.06.12
-697.24
Service (A, B & C)
Remarks
121.75
45.38
31.54
37.15
31.78
33.96
33.85
2.18
152
122.23
45.38
31.54
37.15
31.78
33.85
5.61
2.07
150.8
On IP by pass valve close &
stop valve open position At 09:40 A.M
On IP by pass valve close &
stop valve close position At 12:07P.M
On IP by pass valve close &
stop valve close position At 13:59P.M
On IP by pass valve close &
stop valve close position At 15:26P.M
On IP by pass valve close &
stop valve open position At 09:00AM
On IP by pass valve &
stop valve close position At 14 PM
On IP by pass PCV&
stop valve close position as well as neck spray
to the PCV for decrease of temp. on TE_336C
At 16:00 PM
On normal condition IP bypass PCV close &
stop valve open condition . At: 22PM
On IP by pass valve close &
stop valve open position At 09:00AM
On IP by pass valve &
stop valve close position At 14 PM
On IP by pass valve &
stop valve close position At 15 PM
On IP by pass valve &
stop valve close position At 15 PM
On IP by pass valve &
stop valve close position At 16 PM
On IP by pass valve &
stop valve close position At 16:45PM
The temperature on the IP bypass line(SB-001-FBD-750-P75 ) inlet on condenser (TE-336C) was showing 243.2 deg
at 09:40 am in 12th June,2012.& the vacuum was -691.3 mmHg that time.
The IP bypass line PCV 336B was found passing on the last CI-2012.Continuous condensate was found on that line. The line ends over the tubes of condenser A side.
So the stop valve HV 336B was also stopped on 12th June 2012.The temperature decreased to 232.7 Deg & the vacuum found -701.2 mmHg on 15:26 pm on 12th June,2012.
So the vacuum raise 10 mmHg due to the the reduction of probable passing on the PCV 336B.
On 14th June,2012 the stop valve was again closed for vacuum improvement. But no significant rise of vacuum was observed.
14.06.12 The neck spray was manually operated that time & the condenser IP bypass line inlet temperature TE-336C was reduced from 200°c to 45 °c .The vent line of cooling water inlet was also
vented. But no significant vacuum improvement was observed.

13. Date
Ejector
Vacuum
Pump
Ambient
Temp
Condenser
Vacuum
(mmHg)
PT-032A
HP/IP/LP Feed
Water Flow
(Ton/hr)
HP/IP/LP Feed
Steam Flow
(Ton/hr)
S/T Load
MW
Condenser
Temp
TE(033EA)
°c
Water
Water Box Water Box Box A
Inlet Pr.A Outlet Pr.B Inlet
Bar
Bar
Temp.
°c
Water
Box A
Outlet
Temp
°c .
Water
Box B
Inlet
Temp.
°c
Water
Box B
Outlet
Temp.
°c
Condens
er IP By
Diff. Betn Diff. Betn
pass line
inlet &
inlet &
Inlet
Outlet on Outlet on
Temp
A Side
B Side
(TE°c
°c
336C)
°c
Remarks
The upper isolation valve of HP super heater drain MOV 020A & B was manually closed. Some improvement on flash box was observed. Then the R/H outlet drain valve 320C's
upstream isolation valve was manually colsed.The flash tank tank huge improvement was observerd.The cep discharge to flash tank TCV-033E was 92 % opened before the
operation.After that the TCV was reduced to opening 44%.
16.06.12 then the PCV-336B & HV-336B was closed again .The condenser inlet of IP bypass (TE-336C) was 196°c then it had reduced to 153°c .The probable passing on IP bypass stop valve also.
HIP turbine drain valve 045A,045B.045D & 045 I was showing huge passing .The temperature on the downstream of this valve was observed (139.4°c ,245.3°c ,282.3°c & 504.2°c
).Whereas the other valves are having temp <45°c .
(*All of this operation was done with the help,suggesstion of Operation people *)
17.06.12
The IP bypass stop valve XV-336 & PCV-336B could be calibrated with the help of IC& E.
The main stop valve is not closing properly as the condenser inlet temperature (TE-336C) is not reducing a lot.
HIP turbine drain valve 045A,045B.045D & 045 got huge passing.
The upstream isolation valves of MOV-320c,020A & B have got passing.
The HP super heater drain line to condenser XV-045H might got passing.
The blind flange of condenser shell side shows loose bolts. It should be tightened on convenient time eith proper scaffolding.
All other line flange would be inspected through soap bubble test.
The cooling water inlet vent lines to the condenser will be opened.

14. CONCLUSION
Probable Cause (I) :Air Leakage from condenser shell side.
Answer:-
We have to check all the flanges sealing condition by soap bubble test.
Probable Cause (II) :Circulating water pumps (CWP) are not performing to its design capacity.
Answer:-
The current running data proves that the Cooling Water Pumps (CWP- A& B) are running still
good though they are 12 years old.
Probable Cause (III):Ejectors/vacuum pumps are not performing well.
Answer:-
The analysis shows the ejectors & vacuum pumps still are well enough for the operation.
Probable Cause (IV):Some extra steam load on condenser water box-A side cause the ∆T is extremely higher.
Answer:The IP bypass stop valve HV-336B & PCV-336B has got
huge passing.
The IP bypass line PCV 336B was found passing on the
last CI-2012.Continuous condensate was found on that
line. The line ends over the tubes of condenser A side.
The condensate pressure was 4 bar that time,
while on normal running condition the R/H
outlet pressure is over 28 bar.
HIP turbine drain valve 045A, 045B.045D & 045 got huge
passing.
The upstream isolation valves of MOV-320c, 020A & B
have got passing.
So, this is the probable cause of condenser under performance for the last few years.
I hope the Steam turbine load can be reached to its maximum capacity after those valve maintenance
works on the next Steam Turbine Major inspection on 2013.We hope we can increase our steam
turbine load to 5-7 MW/D on that time.
Thank You All
Page
I would also like to thank our operation team cause they have help us a lot also for problem finding.
So, it’s a combined effort I believe & hope this report will be helpful for our Steam Turbine Capacity
improvement after next MI-2013 & we can operate Steam Turbine like before.
14
This total report is a combined effort from our Haripur Power Limited (HPL) mechanical
maintenance team. I want to thank our MMT Manager Mr. Zahid Hossain & MMT Supervisor Mr. AB
Siddique for their continuous support.