Theoretical investigations on using high-temperature heat pumps in combination with district heating networks.

In recent years, the supply and return temperatures in the district heating sector have been gradually reduced. As a result, district heating systems cannot supply industrial consumers with higher temperature requirements (> 120 °C). Using the district heating supply or return flow as a heat source allows the use of high-temperature heat pumps to supply process heat above 120 °C to existing and new businesses. In order to find an optimal heat pump solution for the given boundary conditions, a systematic investigation is required. This article deals with a variety of influencing factors (i.e., different refrigerants, circuit types, source and sink temperatures) that affect the COPh of high-temperature heat pumps. All heat pump circuits are modeled and simulated using EBSILON®Professional. The results of the study provide the district heating sector and industry with valuable information to promote the use of high-temperature heat pumps in combination with district heating networks.