Fault of Electric Cable
Energy Bands in Crystals
Gallium Arsenide Semiconductor
Atomic Energy Levels
Electric Pressure Cooker
Electric Power Generation
Power Plants and Types of Power Plant
Thermal Power Generation Plant or Thermal Power Station
Hydro Power Plant | Construction Working and History of Hydro power plant
Nuclear Power Station or Nuclear Power Plant
Diesel Power Station
Why Supply Frequency is 50 Hz or 60 Hz?
Economiser in Thermal Power Plant | Economiser
MHD Generation or Magneto Hydro Dynamic Power Generation
Cogeneration | Combined Heat and Power
Thermoelectric Power Generators or Seebeck Power Generation
Cost of Electrical Energy
Gas Turbine Power Plant
Steam Boiler | Working principle and Types of Boiler
Methods of Firing Steam Boiler
Fire Tube Boiler | Operation and Types of Fire Tube Boiler
Water Tube Boiler | Operation and Types of Water Tube Boiler
Steam Boiler Furnace Grate Firebox Combustion Chamber of Furnace
Feed Water and Steam Circuit of Boiler
Boiler Feed Water Treatment Demineralization Reverse Osmosis Plant Deaerator
Coal Combustion Theory
Fluidized Bed Combustion | Types and Advantages of Fluidized Bed Combustion
Steam Condenser of Turbine
Jet Condenser | Low Level High Level Ejector Jet Condenser
Surface Steam Condenser
Economics of Power Generation
Cooling Tower Useful Terms and Cooling Tower Performance
Cooling Tower Material and Main Components
Power Plant Fire Protection System
Hydrant System for Power Plant Fire Protection
Medium Velocity Water Spray or MVWS System for Fire Protection
Foam Fire Protection System
Fire Detection and Alarm System
Gas Extinguishing System
Solar Energy Solar Electricity
Solar Energy System | History of Solar Energy
Types of Solar Power Station
Components of a Solar Electric Generating System
What is photovoltaic effect?
Staebler Wronski Effect
Working Principle of Photovoltaic Cell or Solar Cell
Characteristics of a Solar Cell and Parameters of a Solar Cell
Solar Cell Manufacturing Technology
What is a Solar PV Module?
What is Standalone Solar Electric System?
Steam Dryness Fraction
Superheated Steam and Steam Phase Diagram
Vapour Properties Mollier Chart Heat Capacities
What is Steam Flashing?
How to Calculate Steam Consumption During Plant Start Up
Effective Steam Distribution System
What is Water Hammer?
Engineering Thermodynamics Part 1
Science of Engineering Thermodynamics Part 2
Basic Law of Conservation and First Law of Thermodynamics
Carnot Cycle and Reversed Carnot Cycle
Enthalpy Entropy and Second Law of Thermodynamics
Rankine Cycle and Regenerative Feed Heating
Rankine Cycle for Closed Feed Water Heaters and Rankine Cycle Cogeneration
Ideal Verses Actual Rankine Cycle
Rankine Cycle Efficiency Improvement Techniques
Basic Wind Energy
Wind Turbine | Working Types and History of Wind Turbine
Theory of Wind Turbine
Cogeneration | Combined Heat and Power
The exhaust steam is then sent to the condenser, where it gets cool down and gets converted to water and hence return back to boiler for producing more electrical energy. The efficiency of this conventional power plant is 35 % only. In cogeneration plant the low pressure steam coming from turbine is not condense to form water, instead of it its used for heating or cooling in building and factories, as this low pressure steam from turbine has high thermal energy. The cogeneration plant has high efficiency of around 80 - 90 %. In India, the potential of power generation from cogeneration plant is more than 20,000 MW. The first commercial cogeneration plant was built and designed by Thomas Edison in New York in year 1882. As shown in above diagram, in traditional power plant, when we gave fuel as input we get electrical energy and losses as output but in case of cogeneration with fuel as input, the output is electrical energy, heat or thermal energy and losses. In convential power plant, with 100 % energy input ,only 45 % of energy is used and rest 55 % is wasted but with cogeneration , the total energy used is 80% and energy wasted is only 20 % . It means with cogeneration the fuel utiliuzation is more efficient and optimized and hence more economical.
Need for Cogeneration
- Cogeneration helps to improve the efficiency of the plant.
- Cogeneration reduce air emissions of particulate matter, nitrous oxides, sulphur dioxide, mercury and carbon dioxide which would otherwise leads to greenhouse effect.
- It reduces cost of production and improve productivity.
- Cogeneration system helps to save water consumption and water costs.
- Cogeneration system is more economical as compared to conventional power plant.
Types of Cogeneration Power PlantsIn a typical Combined heat and power plant system there is a steam or gas turbine which take steam and drives an alternator. A waste heat exchanger is also installed in cogeneration plant, which recovers the excess heat or exhaust gas from the electric generator to in turn generate steam or hot water. There are basically two types of cogeneration power plants, such as-
- Topping cycle power plant
- Bottoming cycle power plant
- Combined-cycle topping CHP plant - In this type of plant the fuel is firstly burnt in a steam boiler. The steam so produced in a boiler is used to drive turbine and hence synchronous generator which in turn produces electrical energy. The exhaust from this turbine can be either used to provide usable heat, or can be send to a heat recovery system to generate steam, which maybe further used to drive a secondary steam turbine.
- Steam-turbine topping CHP Plant- In this the fuel is burned to produce steam, which generates power. The exhaust steam is then used as low-pressure process steam to heat water for various purposes.
- Water- turbine topping CHP Plant- In this type of CHP plant a jacket of cooling water is run through a heat recovery system to generate steam or hot water for space heating.
- Gas turbine topping CHP plant- In This topping plant a natural gas fired turbine is used to drives a synchronous generator to produce electricity. The exhaust gas is sent to a heat recovery boiler where it is used to convert water into steam, or to make usable heat for heating purposes.
Bottoming cycle power plant - As its name indicate bottoming cycle is exactly opposite of topping cycle. In this type of CHP plant the excess heat from a manufacturing process is used to generate steam, and this steam is used for generating electrical energy. In this type of cycle no extra fuel is required to produce electricity, as fuel is already burnt in production process.
Configuration of Cogeneration Plant
- Gas turbine Combine heat power plants which uses the waste heat in the flue gas emerging out of gas turbines.
- Steam turbine Combine heat power plants that use the heating system as the jet steam condenser for the steam turbine.
- Molten-carbonate fuel cells have a hot exhaust, very suitable for heating.
- Combined cycle power plants adapted for Combine Heat and Power.