water optimization coastal gujarat power...
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Water Optimization Coastal Gujarat Power Ltd.
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Plant Design Parameter
Technology : Super-Critical, Pulverised Imported Coal-fired Seawater based power plant (Steam conditions atSteam Turbine inlet to be 242 bar (g), 565 °Csuperheat / 593 °C reheat).
Nos. of Units : Five (830 MW x 5)
Nos. of Stacks : Two 275 m high multi-flue stacks
Type of Fuels : Imported Coal
Cooling System : Once-through system
Water Source and Utilization at CGPL
Water RequirementPlant Water Usage Water Requirement
(m3/hr)Type of Water
For CW System 567625 Sea WaterMakeup for Boilers 148 DM Water
Makeup to HVAC System 300 Service WaterPotable Water 1.5 Produced from Sea Water
Makeup to Ash handling system
79 Sea water
Service Water System 778 Produced from Sea WaterCHP-Dust Suppression
system217 Service water
Water Source – All the water requirement are fulfilled from Sea Water
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Water Consumption & Savings
Water Optimization( Effluent collection-Treatment- Recycle-Reuse)CPU regeneration ,DM regeneration coal runoff pit water treated through ETP and supplied
to green belt and reused as gardening water. Approx.398 hector green belt area has beendeveloped through ETP water )
Measures carried for saving of different types of water:All plant storm water drain has been connected to rain water harvesting system.From rain water harvesting system water being used at Coal handling plant sprinkler system for dust suppression.
Fire water Hydrant Pressure Monitoring Unit at CGPL:
Fire water Hydrant Pressure Monitoring Unit at CGPL:Online Pressure transmitter installed at fire water line furthest and highest point. Pressure transmitter value has been provided in PI system so that we can monitor pressure & in case of leakage in fire hydrant system same has been rectified promptly.
Earlier firewater lines were underground so it was difficult to identify underground leakages, The monitoring help us in early identification of line leakage instantly .
Instead of manual RC valve auto pressure control valve installed in system to maintain desired pressure as well as helping in monitoring of consumption
Fire water Hydrant Pressure Monitoring Unit at CGPL:
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Use of steam pegged deaerated water for boiler filling and cleaning to achieve minimum time and corrosion: (O&M Best Practice)
\\172.16.117.3\MU 30 DEA LEVEL\\172.16.117.3\MU 30 DEAERATOR TEMP145.89DEG C
DEAERATOR TEMP15-Jul-17 1:57:19 AM14-Jul-17 4:02:14 PM 9.92 hours
Plot-0
70
80
90
100
110
120
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140
150
DM Water filled to boiler is maintained at proper pH and also de
aerated by steam pegging i.e.
maintained 105 deg C + for reduction of dissolved oxygen
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SWRO Permeate water remineralization:
PARAMETERSRain feed
River Water
Ground Water
SWRO Water
Conductivity(µs/Cm) 140 3200 900
pH 7.2 8.0 7.0
Ca(PPM) 40 240 6
Mg(PPM) 25 60 14
Alkalinity(PPM) 55 320 12
Cl (PPM) 12 820 260
Comparison of different types of water:
Though SWRO water brings down the TDS level to fresh water level but availability of different ions in that water does not match with normal river water on which we have all the experience, so the problem came when we used MS line for fire and service water.
Kutch in Gujarat having no fresh water source other than ground water. CGPL-Mundra makes all water from sea water and SWRO technology.
Optimization of DM water consumption
0.72%
0.67%
0.55%0.58%
0.37%
0.30%
0.00%
0.10%
0.20%
0.30%
0.40%
0.50%
0.60%
0.70%
0.80%
FY 13 FY 14 FY 15 FY 16 FY 17 FY 18
Station Make-up %
Reduction in DM water consumption by 0.25% saves 1.8 Kcal/kwh in heat rate. Net
saving of 4.43 Cr/annum. (from FY 15 to FY 18)
Continual reduction in DM water consumption from FY 13 to FY 18
•Optimisation in soot blowing operation.
•Reduction in HTPRDS Pressure set point.
•Early identification and rectification of DM water and steam losses points.
•Reduction in clean up and start up time.
Action taken
Effluent Treatment Plant
Guard Pond, Effluent Treatment Plant
Capacity: 1500 M3 (750 M3 Each)
Source of Water: Different Process Drains
Usage: Treated Water is used for Gardening
Clean Up cycle- Time Reduction & Process Optimization
Unit#1019/04/20
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Unit#4006/07/20
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Unit#2017/07/20
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Unit#3021/07/20
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Unit#5001/01/20
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Unit#3018/01/20
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unit#1006/06/20
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unit#3014/07/20
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Unit#1016/09/20
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unit#1026/10/20
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Unit#3026/06/20
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Unit#2013/07/20
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Unit#3030/07/20
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unit#1006/08/20
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Time 69.79 57.6 56.47 26.05 32 19.6 19.8 22.5 19 20 16 14 15 15.4
69.79
57.6 56.47
26.0532
19.6 19.8 22.519 20
16 14 15 15.4
0
10
20
30
40
50
60
70
80
Hou
rs
Time Required for Cleanup (Target 16hours)
Problem Statement
• Cold Start-up time Reduction
Target• Reduction of
clean-up cycle time from 58 hrs. to 28 hrs.
• 24 hrs. to 20 hrs. subsequently in 2 years from FY17
Oil Gun Trial • LDO Test trial
during Boiler Cold flushing
• 1 hr. gain in LP Clean up Time
Installation of double dosing system• Parallel Clean up
of Condensate and Feed water cycle
• 4 hrs gain in LP Clean up time
Automation of Startup tool
• Real time gap identification with bench mark and
• Trigger alarm to take proactive action & preparation
Clean Up cycle- Time Reduction & Process Optimization
• Maintain Deaerator temperature over 110o C during filling of boiler to ensure least % of O2 present in boiler water. As O2 is less there is less chance of corrosion and less cleanup time required. Even in case of hydro test feed water temperature is kept at higher side & later ID fan started to cool down boiler.
• Vacuum pulling activity started after starting CEP. Due to low pressure in Hotwell, deaeration or O2 removal starts early. Earlier we used to start the vacuum pulling activity just before light up.
• A dump line to atmosphere installed at CEP discharge , Incase hot well water turbidity increases over 10NTU then dump condensate to atmosphere and take fresh water. Earlier in case of water contamination it was drain through deaerator and thus loosing heat and time.
• Steam blowing through HP-LP bypass started to remove exfoliated material inside superheater and reheater tubes, if turbidity increases Dump line is opened.
• Temporary pump is installed to assist conduit filling trough adjacent filled seal well to speed up CW pump startup.
• A check sheet developed for Oil guns, after implementation of the same oil gun availability increased.
BRP(boiler recirculation pump) online NRV checking operation procedure developed ,thus unnecessary unit tripping and delay averted during wet to dry mode conversion .
Mill to be taken into service after achieving 40kg boiler pressure, it will prevent sudden metal temperature rise in superheater and reheater and prevent exfoliation.
Clean Up cycle- Time Reduction & Process Optimization
• QC NRV’S mandatory operation checking incorporated in every startup.
• Mills HAD and CAD mandatory operation checking incorporated in every startup.
• CW discharge hydraulic valve logic changed and now fast closing modification implemented to prevent conduit drain.
• Turbine TSI parameters are captured in the gap analysis ,which gives a ready reference for next startup and ensure healthiness of our major equipment.
• BFP lube oil level switch replaced to online lube oil transmitter. We can preplan oil top-up activity thus reduce time delay.
• During shutdown to ensure gradual cooling of pressure parts in boiler to minimize exfoliation, we have adopted hot box up procedure. Boiler should be hot boxed up for 8 hours after normal shutdown.
• Double dosing system incorporated for simultaneous clean up of condensate and feedwater cycle.
• Start-up checklist for turbine and boiler area prepared.
Service Water Consumption
CW CT Basin Makeup
BA Pump House
Boiler Header
TG Header
ICHS & ECHS
Aashiyana Township
Labor Colony
Unit 10 – 50 MOC Line
Cooling Towers makeup water
Fire Water System
ICHS
Main Plant
Service Water System
CW CT Basin Makeup
BA Pump House
Boiler Header
TG Header (C Row)
ICHS & ECHS
Aashiyana Township
Labor Colony
Unit 10 – 50 MOC Line (A Row)
Cooling Towers makeup water
SERVICE WATER CONSUMPTION 2018 – 2019 till 21/02/19
1222511514 11853 11948
12321 12130 1234711523 11865
10957
9828
9597
8000
9000
10000
11000
12000
13000
14000
15000
Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19
SERVICE WATER CONSUMPTION TREND (M3) 2018 - 2019
Service Water Reduction after replacement of SW & FW Line: 11800 M3/day to 9800 M3/day Per Day Saving: 2000M3/Day Cost of Generation: 38/M3
Per day Saving: 2000x38= 76000/-Day Annual Saving: 2.77 Crores
Full Fire System Outage
18
7
43
0
4
8
12
16
20
FY 16 FY 17 FY 18 FY 19
Measures undertaken for Water conservation
Measures Short term Measures Medium Term Measures Long-termWater metering ( measuring)
Development of MIS- online system for Water consumption monitoring
Reducing leaks and over flows Revisit design criteria modify and improveBring all underground water pipe lines to surface
Rain Water collection & Utilization
)
Enhance Waste Water Reutilization (Quantify)-ETP & STP
Private and Confidential | 01
COI Water Management Platform at Tata Power
• We have a community of interest ( COI) platform across our Tata Power level for water management.
• Through COI platform we are sharing our best practices, ideas & resolve issues with other divisions.
• KPIs are being given to all divisions and being tracked & shared to COI in each month.
Thank You!Website: www.tatapower.com
Email Id: [email protected]
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