Engines for combined heat and power plants are operated with different fuels, including hydrogen, natural gas, biogas, sewage gas and special gases, plus diesel and other liquid fuels. In an exhaust gas heat exchanger, the hot exhaust gas from the CHP engines or CHP gas turbines is cooled, in the process heating water, a water-glycol mixture or thermal oil. This thermal energy can be used in a local or district heating system or for other industrial purposes.
