ADVANTAGES OF COGENERATION
1) Co-generation can meet both power & heat needs.
2) Less cost than conventional generation.
3) Higher system efficiency as energy wastage is highly reduced.
4) Reduction in emission of pollutants due to reduced fuel consumption.
5) A much more efficient use of primary energy can be achieved than with a separate production of electricity &
heat.
6) In this system, heat generated is by-product in electricity generating process.
7) Due to decentralization of electricity supply it avoids transmission losses & makes system more flexible.
APPLICATIONS OF COGENERATION
1.Sugar mills 2. Rice mills
3. Petrochemical Industry 4. Distilleries
5. Cement Industry 6. Pulp and paper industry
7. Aluminium Industry 8. National parks
9. Wineries 10. Waste treatment plants
Factors to be considered for selection of co-generation techniques
1) Heat power ratio: It should match characteristics of cogeneration system.
2) Load pattern: For selection of cogeneration system, the type of load, its continuity is important aspect.
3) Type of fuel: Generally the type of fuel is selected according to cost. The cost of fuel should be less.
4) The quality of thermal energy: The quality of steam is decided by temperature & pressure of the steam.
5) Electricity buyback: Sometime the electrical energy generated in cogeneration system is sold out to supply
company, after that whenever that factory is need of electrical power; it is purchased from Supply Company by
common electricity buyback agreement.
6) Grid dependent & independent system technology: There are various technology systems applicable for grid.
7) Local environment regulations: In this regulation for cogeneration system we have to study all environmental
conditions, politics & other regulation factors also.
8) Base electrical load matching: By cogeneration system the minimum electricity demand should be supplied.
9) Electricity load matching: It is the stand alone system or it is totally independent system in which the 100%
electrical energy is achieved by the cogeneration system.
10) Base thermal load matching: The minimum thermal energy can be achieved by our cogeneration system & if
required for additional thermal energy can be generated from purchased power of supply company or grid system.
11) Thermal load matching: In this system the 100% thermal energy is achieved by cogeneration system.
, NEED FOR CO-GENERATION
➢ In conventional power plant efficiency is only 35% & remaining 65% of energy is lost.
➢ The conventional system uses energy of fuel to produce Electrical energy or Thermal energy. Where as
co-generation system produces both electrical energy & thermal energy from same flues.
➢ The overall efficiency of energy use in co-generation can be up to 85% and above.
➢ Lower volumes of CO2 emissions compared to the conventional system where separate production of
electricity & heat.
➢ In co-generation system, heat generated is by-product in electricity generating process. This heat can be
used for other processes.
➢ Due to this energy cost are lowered. Limited need of cooling water in co-generation system therefore
reduces thermal pollution.
COMBINED CYCLE TOPPING SYSTEM
➢ The combined cycle topping system is as shown in above fig. In this system the fuel & air is burnt in the
combustion chamber for e.g. diesel or gas engine by which mechanical energy is obtained & it is coupled
to the generator so in first stage electrical energy is generated.
➢ But in next stage the exust gases are passed through the exhaust heat boiler which generates sufficient
steam pressure to drive secondary steam turbine which is coupled to the generator by which electrical
energy is obtained in next stage also.
➢ In later stage the steam output from the turbine is provide to the heat exchanger to produce the usable heat.
1) Co-generation can meet both power & heat needs.
2) Less cost than conventional generation.
3) Higher system efficiency as energy wastage is highly reduced.
4) Reduction in emission of pollutants due to reduced fuel consumption.
5) A much more efficient use of primary energy can be achieved than with a separate production of electricity &
heat.
6) In this system, heat generated is by-product in electricity generating process.
7) Due to decentralization of electricity supply it avoids transmission losses & makes system more flexible.
APPLICATIONS OF COGENERATION
1.Sugar mills 2. Rice mills
3. Petrochemical Industry 4. Distilleries
5. Cement Industry 6. Pulp and paper industry
7. Aluminium Industry 8. National parks
9. Wineries 10. Waste treatment plants
Factors to be considered for selection of co-generation techniques
1) Heat power ratio: It should match characteristics of cogeneration system.
2) Load pattern: For selection of cogeneration system, the type of load, its continuity is important aspect.
3) Type of fuel: Generally the type of fuel is selected according to cost. The cost of fuel should be less.
4) The quality of thermal energy: The quality of steam is decided by temperature & pressure of the steam.
5) Electricity buyback: Sometime the electrical energy generated in cogeneration system is sold out to supply
company, after that whenever that factory is need of electrical power; it is purchased from Supply Company by
common electricity buyback agreement.
6) Grid dependent & independent system technology: There are various technology systems applicable for grid.
7) Local environment regulations: In this regulation for cogeneration system we have to study all environmental
conditions, politics & other regulation factors also.
8) Base electrical load matching: By cogeneration system the minimum electricity demand should be supplied.
9) Electricity load matching: It is the stand alone system or it is totally independent system in which the 100%
electrical energy is achieved by the cogeneration system.
10) Base thermal load matching: The minimum thermal energy can be achieved by our cogeneration system & if
required for additional thermal energy can be generated from purchased power of supply company or grid system.
11) Thermal load matching: In this system the 100% thermal energy is achieved by cogeneration system.
, NEED FOR CO-GENERATION
➢ In conventional power plant efficiency is only 35% & remaining 65% of energy is lost.
➢ The conventional system uses energy of fuel to produce Electrical energy or Thermal energy. Where as
co-generation system produces both electrical energy & thermal energy from same flues.
➢ The overall efficiency of energy use in co-generation can be up to 85% and above.
➢ Lower volumes of CO2 emissions compared to the conventional system where separate production of
electricity & heat.
➢ In co-generation system, heat generated is by-product in electricity generating process. This heat can be
used for other processes.
➢ Due to this energy cost are lowered. Limited need of cooling water in co-generation system therefore
reduces thermal pollution.
COMBINED CYCLE TOPPING SYSTEM
➢ The combined cycle topping system is as shown in above fig. In this system the fuel & air is burnt in the
combustion chamber for e.g. diesel or gas engine by which mechanical energy is obtained & it is coupled
to the generator so in first stage electrical energy is generated.
➢ But in next stage the exust gases are passed through the exhaust heat boiler which generates sufficient
steam pressure to drive secondary steam turbine which is coupled to the generator by which electrical
energy is obtained in next stage also.
➢ In later stage the steam output from the turbine is provide to the heat exchanger to produce the usable heat.
