Cogeneration (CHP) Definition – Types of Cogeneration Power Plants

Cogeneration or CHP (combined heat and power) is the utilization of a heat engine for generating both heats as well as electricity simultaneously. In general, thermal power stations, as well as heat engines, do not change the existing energy into electrical energy. Most of the engines waste half of the main energy due to surplus heat. By capturing the surplus heat, combined heat and power utilizes heat that would be wasted in a standard power station, potentially attaining a total efficiency ranges from 80 to 95%, contrasted by at most 40% for the standard power plants. This means that a low fuel to be utilized for producing the equal quantity of required energy. Because there is a high capacity in energy efficiency, CHP is considered to be the main provider to weather change improvement as presenting reasonable as well as consistency benefits on the supply of energy. This article gives an overview of Cogeneration and its types.

What is Cogeneration?

The term Cogeneration or CHP (combined heat and power) can be defined as, it is the combination of two energies namely heat & power, used for generating current and well as heat. This is an extremely efficient type of energy alteration, which can get 40% main energy savings when we compared by the separate acquire of electricity from the national grid as well as a gas boiler intended for onsite heating. CHP plants are normally fixed near to the consumer end thus the transportations, as well as distribution losses, will be reduced, and the electricity transmission & distribution performance will be improved. For power consumers where the safety of supply is a significant factor for their power selection manufacture apparatus & gas is plentiful. The cogeneration systems based on gas are preferably suited as captive-power plants.

Cogeneration System
Cogeneration System

Components of Cogeneration          

The fundamental components of a combined heat and power system include the following.

  • Prime Mover is an engine used to make the generator run.
  • Fuel System
  • The Generator is used to generate electricity from the power distribution system into the building’s
  • Heat Recovery System is used to pick up utilizable heat from the locomotive (engine).
  • Cooling System for dissipating heat which is rejected from the locomotive that cannot be improved
  • Combustion & Ventilation Air Systems for supplying clean air and to carry waste gases left from the engine,
  • Control System is used for maintaining secure & proficient operation
  • The Enclosure is used for achieving the protection for the engine as well as machinists, and also for reducing noise.
Components of Cogeneration
Components of Cogeneration

Types of Cogeneration Power Plants

Basically, the types of cogeneration power plants are classified based on the operating process and energy utilization series. Therefore, the types of cogeneration systems are a topping cycle and a bottoming cycle.

Types of Cogeneration Power Plants
Types of Cogeneration Power Plants

A Topping Cycle

In this type of power plant, if the supplied fuel is used first for generating power then, afterward in the procedure it generates thermal energy. This energy is mainly used for satisfying process heat otherwise other thermal supplies. This type of cogeneration is the most popular as well as the widely used cogeneration system. A topping cycle power plants are basically classified into four types.

Combined Cycle CHP Plant

A combined cycle CHP plant mainly comprises of a diesel engine otherwise a gas turbine which generates electrical power or mechanical power tracked through a heat improvement system which is useful in generating steam as well as drives a resultant steam turbine.


Steam Turbine CHP Plant

Steam turbine CHP plant is used to generate electrical power & process vapor through burning coal for generating high force vapor, which is afterward agreed by a steam turbine for generating the required power, and then the exhaust vapor is used as low force procedure steam to heat up water intended for a variety of purposes.

Internal Combustion Engine

An internal Combustion Engine CHP plant includes a cover of cooling system water is flowing through a heat recovery system for producing vapor otherwise hot water for gap heating.

Gas Turbine

In this gas turbine CHP plant, a normal gas turbine is used to drive a generator for electricity generation. The turbine exhaust is supplied using a heat recovery boiler for generating process heat and steam.

Bottoming Cycle System

In a bottoming cycle CHP plant, the main fuel is utilized for generating thermal energy at a high-temperature. The heat discarded in this method is then utilized for generating power using a recovery boiler and a turbine generator. These days, this type of plants is extensively used in the process of manufacturing that needs heat at high-temperatures in boilers, as well as refuses heat at very high temperature. Although they are used in industries like cement, steel, ceramic, petrochemical, gas, etc. Bottoming cycle plants are not frequent & not applicable for topping cycle plants.

Need for Cogeneration

The need for Cogeneration include the following:

  • Cogeneration reduces the manufacturing price and enhances output.
  • The plant efficiency can be progressed.
  • It helps to conserve utilization of water as well as the cost of water.
  • This is used to reduce an air emission of specific material like mercury, sulfur dioxide, carbon dioxide, otherwise, it would lead to the greenhouse effect.
  • These systems are inexpensive when we contrasted to the usual power station.

How to Select Cogeneration System

There are many factors that are taken into consideration while selecting the cogeneration system.

  • Electrical -load matching
  • Thermal- load matching
  • Base-electrical load matching
  • Base-thermal load matching
  • Heat-to- power ratio
  • The quality of thermal energy required
  • Load outlines
  • Existing Fuels

When Should We Consider CHP?

  • It should always be considered when:
  • Designing a new building
  • Fitting new boiler plant
  • Replacing or refurbishing the existing plant
  • Reviewing Electrical Supply
  • Primary energy fuel
  • Motor element supplier of mechanical work to the shaft

Thus, this is all about Cogeneration and Its types, and the cogeneration applications in power plants mainly involved in an extensive range of sectors namely wastewater treatment, military, industrial, data centers, leisure, hotels, hospitals, prisons, education establishments, horticulture, mixed developments, etc. Here is a question for you, where the linden cogeneration plant located?