S O U R C E O F W A T E R : R I V E R H O O G H L Y
D A I L Y A V E R A G E I N T A K E : 4 0 , 0 0 0 K L
Plant Water Systems
Raw Water System
Clarified water System
DM Water System
DMCW system
CW System
ACW System
Service Water System
Plant Waters Systems
Fire Water System
Drinking Water System
DS System
Seal Water System
BA Zero Discharge System
Uses of Different Water
Raw water: Main source of water (from River Ganges).
Clarified water: Forebay make up, Service & Fire water.
DM water: Power cycle make up, DMCW make up.
DMCW: Cooling medium in different Boiler & TG aux. and Compressors.
Circulating Water: Condensation of steam in condenser
Aux. Cooling Water: DMCW cooling & TG Lub oil cooling.
Service Water: Washing , cleaning & different cooling purpose.
Uses of Different Water
Fire Water: Hydrant water & Mulsifire water
Drinking Water: Drinking
DS System: for dust suppression & fire management at coal stock pile
Seal Water System: for gland sealing of HP/LP Pp. & HCSS Charge Pp
BA Zero Discharge System: for bottom ashing
Specification of Intake Pumps
Make: Kirloskar Brothers Ltd
Type: Centrifugal
Capacity: 1750 m3 / Hr
Head (shut off): 41 m
Head ( dynamic): 28 m
Speed : 980 rpm
Efficiency: 86.05%
Power input: 155.07 kW
Impurities at RAW Water
1. Suspended Particles
a. Can be settled out (Silica)
b. Collidal Impurities (slightly –ve charged
particles )
2. Dissolved Impurities ( minerals )
3. Dissolved Gasses (CO2, O2)
4. Organic Impurities (Algae, Bacteria, Fungi)
Impurities at Ganges water
Bicarbonate salts
Silica
Chlorides & Sulphate (Trace)
Oil & Biocides
Effects of Impurities
Sodium/Iron/Copper : Boiler/Turbine Deposits.
Bicarbonate Hardness : Boiler/Turbine Deposits
Organics/Oil : Foaming in Boiler Drum
Silica : Boiler/Turbine Deposits
Dissolved O2 & CO2 : Corrosion by localised cell formation
FM
Flocculation Tank
ISS
Raw water from River Ganges
CWR
FWR DMP
Raw water System
Daily Consumption:46000Ton
Raw water treatment
Processes:
1. Coagulation process
2. Chlorination process
3. Ion exchange process
Raw water treatment
Raw water to Clarified water:-
1. Alum dosing: to remove colloidal impurities
2. Polyelectrolyte dosing: to remove colloidal impurities
3. Sodium hypo-chloride: to remove organic impurities
4. NaOH dosing at FM: to reduce Ca loading.
Clarified Water Parameters
CWR water quality: • Total Hardness: 80 – 150 ppm
• Total Anion: 170 ppm as CaCO3
• Silica: 8 – 12 ppm as SiO2
• Chloride: 15 – 25 PPM as CaCO3
• Sulphate: 5 – 10 ppm as CaCO3
• Turbidity: 5 NTU
• pH: 7.0 to 7.5
ACF
FWR
SAC DG
Blower WBA SBA
MB DMST
GSF
De-mineralisation System
De-mineralisation
Clarified water to DM water:-
1. GSF: removes suspended particles
2. ACF: for Organic impurities, excess Cl2 & colour, odor.
3. SAC (Strong Acid Cation): to remove salts of Ca, mg, Na etc.
Ca(HCO)3 + R-H : R-Ca + H2CO3
4. Degasser: removes dissolved Co2 & H2Co3
De-mineralisation
5. WBA(Weak Base Anion): Strong anions are removed
H2SO4 + R-OH = R2SO4 + H2O
HCl + R-OH = RCl + H2O
6. SBA(Strong Base Anion): Weak anions like Si
H2SiO3 + R-OH : R2SiO3 + H2O
7. MB(Mixed Bed): Residual / spillage cations & anions are removed
Limiting DM Water parameters
Ph : 6 – 7.2
Conductivity : < 1.2 µs/cm
Silica : < 0.02 ppm
DM storage capacity
DMST ( 2 nos) : 1000 Ton
CST (2 nos) : 800 Ton
DMCW circuits
The two DMCW circuits are interconnected through Main plant Compressor supply & return lines.
Number of DMCW pumps : 4 nos for unit-1 & 3 nos for unit-2
Point of usage : All Coolers & Heat exchangers except where ACW is used
Specification of DMCW Pumps
Make: M/s Beacon Weir
Type: Centrifugal
Capacity: 870 cum/hr
Total head: 48 m
Efficiency: 84%
NPSHR: 5.7 m
Speed: 1480 rpm
Power Input: 130.71 kw
DMCW parameters & Treatment
Caustic (NaOH) dosing is done at DMCW tank to maintain the alkalinity (to avoid acid corrosion)
Parameters:
Ph: 8.5 to 8.8
Conductivity: 3 µs/cm
CW system
Number of pumps : Two for each unit (discharge side interconnection provided)
Water source: Forebay
Discharge valve is hydraulically operated
Supplies water only to Condenser
The water gets cooled in Cooling Tower
Specification of CW Pumps
Make: WPIL
Capacity: 15500 m3/hr
Speed: 497 rpm
No of stages: single
Total dynamic head: 26 mwc
Pump efficiency: 89%
Pump input at dynamic pr.: 1233.14 kw
ACW system
Number of pumps : Two for each unit (discharge side interconnection provided)
Water source : Forebay
Discharge valve is electrically actuated
Return line is connected with CW return line
Supplies water only to TG Lub oil Cooler, Nash pump cooler, Central AC plant Condenser (new provision) & DMCW HEX.
Provision of CT blowdown from CW-ACW return line.
The CT blowdown water is consumed through Service water & Zero discharge make-up.
Specification of ACW Pumps
Make: Kirloskar Brothers Ltd
Type: Centrifugal
Capacity: 2400 m3/hr
Head: 34.358 MWC
Speed: 1485 rpm
Input power: 250.9 kW
Forebay water treatment
H2SO4 dosing: to reduce by-carbonate salt.
Chembond dosing: to increase the solubility of salt to avoid scale formation.
NaOCl dosing: to destroy the organic matters.
Forebay water parameters
Ph : 8.5 – 8.9
Turbidity : < 20 NTU
Free Chlorine : < 0.5 ppm
Service water system
Number of pumps : 4
Suction side can be connected to CT blowdown as well as CWR
Usage : Washing/cleaning, Air Heater & ESP hopper cooling, ESP fogging, Sludge water pump gland cooling, Ammonia gas cylinder cooling, Dust Suppression tank make-up, Intake pump gland & Bearing cooling
Provision for interconnection with Hydrant line
Hydrant &
Mulsifyre
Pumps
Hydrant Pumps supply water at 9 Kg/Cm2 pressure through the network.
Hydrant Pumps -02 (Elec), 01(Diesel)
Mulsifire Pump- 01 (Elec), 03(Diesel)
Jockey
Pumps
There are two Jockey pumps which maintain the water pressure in both
Hydrant & Mulsifyre System
Hydro
pneumatic
Tank
This tank can store sufficient volume of water at 9 Kg/cm2 pressure and
is connected to both hydrant & mulsifyre systems . Two motor driven
compressors maintain the pressure inside the tank
Source of
Water for
Fire
Fighting
An underground Reservoir is connected to CW Forebay (capacity 7000
M3). This capacity enables the three Hydrant Pumps to spray water for
TWO HOURS and two High Velocity Water pumps for FOUR HOURS
simultaneously
Fire Water System
Cooling Towers
No. of Cooling Towers: 4
No. of Cell: 2*10 in Unit-1 & 2, 6 in Unit-3
No. of fans: 20 in Unit 1 & 2. 6 in Unit-3
Model: Induced draft counter flow cell cooling tower
Type of Fan: Axial flow
Rated speed: 740rpm / 1480 rpm
Power Input: 14 / 55kw Hot water temperature: 43oC
Cold water temperature: 33oC
CT efficiency : 78%
Compressed Air Systems
(1) Instrument air (2) Service air are of Reciprocating Type Number of IA Comp : 11 (No After cooler, discharge goes to ADP) Modes : Base-1, Base-2, S/B-1 & S/B-2 Provision of bleeding in local IA receivers for ID/FD/PA fan suction
vanes for prevention of moisture ingression into I to P converters Number of SA Comp : 3 (with After cooler) Modes : Base, S/B-1 & S/B -2 Provision of interconnection of SA with F&A IA system Provision of bleeding holes in oil gun atomizing bus for prevention
of moisture ingression in oil guns Number of ADPs : 3 Comp motor rating : 140 KW, 415 volts (3)Conveying Compressor are of Centrifugal type.
Basic Layout of IA system at FHP & AHP
IA-2
IA-3
IA-4
IA-5
IA-1 H O T
A I R
B U S
ADP-1
ADP-2
ADP-3
ADP-4
AIR
RECEIVER
Different uses of compressed air
IA is used for controlling purpose (Dumper or valve operation, FG operation etc), BOBR unloading, Ash evacuation system, Dry Fog System & Generator purging.
Conveying Air required for Fly Ash Evacuation
Screw Compressor Discharge Air used in multipurpose by change over of valves.
Service Air Compressor used for Atomization of oil and for other cleaning & Brg. Cooling purpose.
Specification of different compressors
Reciprocating Compressors:
Make: Chicago Pneumatic (I) Ltd
Type : Horizontal, stationary, reciprocating
Quantity : 19 (IA: 12,SA: 4, Conv. Comp: 3)
Capacity 25 m3/min
Discharge pressure : 8 kg/cm2 g
Compressor efficiency: 83%
Volumetric efficiency: 75.8%
Input power: 140.3 kw
Speed: 635 rpm
No of stages : 2
Specification of different compressors
Centrifugal Compressors:
Make: Kirloskar Pneumatic Co. Ltd
Type : Centrifugal
Quantity : 4
Capacity 60 m3/min
Discharge pressure : 3.7 kg/cm2 g
Input power: 675 Kw
Cooling: Water Cooled Intercooler, After
Cooler and oil cooler
Lubrication: Forced Feed Lubrication
Specification of different compressors
Screw Compressor:
Make: Ingersoll Rand
Type: Screw
Quantity: 1
Capacity: 20 m3/min
Discharge Pressure: 7 kg/cm2
Input Power: 128 Kw
Thank You