Waste Heat Recovery in Power Stations

1. ENERGY CONSERVATION SOLUTIONS
for a better planet
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2. WASTE HEAT RECOVERY IN POWER STATION BOILERS
 In the recent years, the concept of LT Economisers generally
known as GAS HEAT EXCHANGER (GHE) for Thermal Power
Stations, are used to enhance the system efficiency. The
objectives to develop the GHE are
 To reduce the exhaust gas temperature from 160 ~ 170 Deg C
to about 110 ~ 120 Deg C
 While a Desulphurisation / Denitrification equipment are
considered, the GHE shall assist to reduce the inlet gas
temperature thereby reducing the water consumption
 Similarly, to reduce the inlet gas temperature for the next
generation ESPs.
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3. METHODS OF INCORPORATION
 OPTION-1: GHE installed after the ID Fan
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4. METHODS OF INCORPORATION
 OPTION-2: GHE installed before ESP
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5. METHODS OF INCORPORATION
 OPTION-3: GHE used to control the flue gas temperature entering
stack
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6. CASE-1: AIR CONDITIONING USING WASTE HEAT FROM
FLUE GAS
 Client: NTPC
 Location: Ramagundam
 Project: 100 TR Air Conditioning using Waste Heat from Flue
Gas
 Project Details: Waste heat recovery air conditioning system is
designed to recover 500 kW of thermal heat from flue gases to
produce 100 tons of refrigeration.
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7. SCHEME - NTPC RAMAGUNDAM (1 x 500MW)
Cooling
Tower
Control Room
for VAM VAM
ID Fan
Flue Gas
Fan
Tubular Heat
Exchanger
Chilled Water Pump
Chimne
y
Unit-4
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8. SYSTEM DESCRIPTION – NTPC RAMAGUNDAM
150°C
110°C
FAN
STACK
ID FAN
HEAT
EXCHANGER
VAM ESP, CCR
Flue Gas
Hot Water
Chilled Water
95°C
85°C
12°C
7°C
Hot Water
Chilled
Water
Flue Gas
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9. BENEFITS
 Air Conditioning using Waste heat of flue gas instead of using
Electricity or Auxiliary steam.
 Reduction in Auxiliary power of 0.4 MU/yr for Ramagundam STPS.
 Green House Gas (CFC & HCFC) free thermally driven 100 TR VAM
based AC system.
 Reduction in CO2 emission is 320 T/yr for Ramagundam Super
Thermal Power Station
 Potential of scale up to meet entire Air-Conditioning requirement
using waste heat from flue gas at power plants
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10. CASE-2: DESALINATION OF SEA WATER USING WASTE HEAT
FROM FLUE GAS
 Client: NTPC
 Location: Simhadri
 Project: 144 TPD Flue Gas Desalination Plant.
 Project Details: Waste heat recovery desalination system is
designed to recover 795 kW of thermal heat from flue gases to
produce 5 TPH of net distillate at less than 5 ppm from 45000
ppm cooling tower blow down water (using 1 TPH, 0.34 bar (a)
saturated steam) using Multi-effect Distillation System.
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11. SCHEME - NTPC SIMHADRI (1 x 500 MW)
Main Flue Gas
Duct
Flue Gas Heat
Exchanger
Flash Chamber
Multi-effect
Distillation
System
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12. NTPC SIMHADRI INSTALLATION
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13. NTPC SIMHADRI INSTALLATION
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14. SYSTEM DESCRIPTION – NTPC SIMAHDRI
Heat Exchanger Flash Chamber MED
Electro
De-ionization
Flue Gas In
Flue Gas Out
Hot Water
Cold Water
Low Pressure Steam
Warm Sea Water
Sea Water In
Sea Water Out
Distillate
Brine Recirculation
Brine
Reject
DM Water
113 TPH / 125 C
113 TPH / 100 C
38 TPH / 90 C
38 TPH / 72 C
1 TPH / 72 C
32 TPH / 44 C
14TPH/
38 C
50 TPH/ 38 C
36 TPH/ 38 C
7 TPH/
49 C
6 TPH / 49 C
1 TPH / 49 C
18 TPH/ 49
C
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15. S.No Description Unit Parameter
1 Capacity Tons/Hr 5
2 Output Water
Desalinated
Water
Conductivity µS/cm 10 (Max)
DM Water
Conductivity µS/cm 0.1 (Max)
Silica ppb 15 (Max)
pH - 6.5 – 7.5
3 Inlet Sea
Water
TDS ppm 45,000 -60,000
pH - 7.6 – 8.0
Temperature Deg C 32.5
4 Flue Gas
Gas Composition (O2 %, CO2 %,
SOx mg/NM3, NOx mg/NM3)
%
6-7, 12-13,
1300-1600, 400-500
SPM mg/NM3 200 - 400
Temperature Deg C 125 - 130
Plant Input & Output Data
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16. BENEFITS
 Retrieval of unused thermal energy from flue gas
 No membrane replacement in the RO desalination plant
 High product water 16 quality of < 2 ppm from Multi-effect Distillation
 Possible to use power plant cooling tower blow down as source water
for desalination
 No chemical handling
 Possibility of 100 % availability
 Reduction in DM plant operating cost
 Electrical energy consumption of 1.5 kWh /m3 for desalination plant
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17. CONTACT US
United Kingdom
GREENS POWER EQUIPMENT UK LIMITED
Suite 1, 3rd Floor, 11-12 St. James’s Square,
London SW1Y 4LB, United Kingdom
Tel: +44 7711537129
Singapore
GREENS POWER EQUIPMENT PTE LIMITED
12 Tannery Road #10 - 01, HB Centre 1,
Singapore 347722
Tel: +65 68991563
China
SHANGHAI GREENS INTERNATIONAL TRADE CO. LIMITED
上海龙凛国际贸易有限公司
NO.8958, PUWEI ROAD, FENGXIAN, SHANGHAI 201417, CHINA
Tel: +86 13917622970
India
GREENS POWER EQUIPMENT INDIA PRIVATE LIMITED
Solitaire Business Hub, Office No. 35, 4th floor,
Kaspate Wasti Road, Wakad, Pune 411057, India
Tel: +91 20 29521215
Email: greens@thegreensgroup.co.uk
Website: www.thegreensgroup.co.uk
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