Combined heat and power plant

Definition

The cogeneration or combined heat and power plant (CHP) is one type of fossil-fuel plant that associates a gas turbine with a heat recovery steam generator (HSRG). Cogeneration is the simultaneous production of two forms of energy (electricity and heat) from a source of fossil fuel (gas-gas, gas-biomass, gas-coal, gas-fuel..).

Concept of the arrangement

In Figure 1, we have two facilities: one of them produces electricity while the other generates heat. The overall performance of the system in this case is 70,6 %, compared to 33% efficiency for the single CCPP cycle.

In Figure 2, we want the same result in terms of electricity and heat produced amounts, but with a cogeneration facility. Heat losses associated to the production of electricity from the gas turbine is reused in the production of heat.

It is explicite that the efficiency has increased from 70.6 to 92.3% while the heat energy supplied to the boiler has dropped from 17 kW to 13 kW.