Cogeneration, also known as Combined Heat and Power (CHP), is the simultaneous production of electrical power and useful heat. Cogeneration systems generally employ “Topping Power Cycle” or “Bottoming Power Cycle”.
Topping Power Cycle:
In contrast to conventional fossil fuel based electric power generation, cogeneration system deliver some of the heat generated as a product which can be used for industrial heating processes and/or space cooling.
Bottoming Power Cycle:
Its basic principle is that high temperature exhaust heat rejected from an industrial process is used to produce steam or hot water, which can then be used to drive a steam turbine to produce electric power.
Both cycles enhance fuel utilization and improve energy conversion efficiency as well as provide a more economic, safe and reliable operation resulting in an overall reduction in operational cost.
In principle, a cogeneration system is composed of prime mover, electric power generator, heat recovery system, and control mechanism. The core of the cogeneration is the energy conversion unit that allows the combined production of electricity and heat. There are a number of different conversion technologies that have been deployed and used in combined heat and power (CHP) applications.