Exploitation of low-temperature energy sources from cogeneration gas engines

• The use of low-temperature waste heat from the CHP is described.
• Total energy efficiency of the CHP can be increased to more than 103.3%.
• Low-temperature heat is exploited with high-temperature heat pump.
• High-temperature heat pump allows temperature rise to up to 85 °C.
• Exploitation of low-temperature waste heat increases the economics of the CHP.

This paper describes an original and innovative technical solution for exploiting low-temperature energy sources from cogeneration gas reciprocating engines installed within district heating systems. This solution is suitable for those systems in which the heat is generated by the use of reciprocating engines powered by gaseous fuel for combined heat and power production. This new technical solution utilizes low-temperature energy sources from a reciprocating gas engine which is used for a combined production of heat and power. During the operation of the cogeneration system low-temperature heat is released, which can be raised to as much as 85 °C with the use of a high-temperature heat-pump, thus enabling a high-temperature regime for heating commercial buildings, district heating or in industrial processes. In order to demonstrate the efficiency of utilizing low-temperature heat sources in the cogeneration system, an economic calculation is included which proves the effectiveness and rationality of integrating high-temperature heat-pumps into new or existing systems for combined heat and power production with reciprocating gas engines.