Reduction of the return temperature in district heating systems with an ammonia-water absorption heat pump

Abstract

In this study, a new setup for the reduction of the return temperature in district heating systems will be presented. For this purpose, an ammonia-water absorption heat pump will be integrated within a district heating substation and theoretically investigated. The idea of this coupling is that the district heating flow is used to power the generator of the heat pump. The district heating return is cooled in the evaporator. In this way, the capacity of the district heating system can be increased or the mass flow rate can be reduced. Additionally, the lower return temperature leads to a higher efficiency of the whole system.The field of possible operating points for such a system is also revealed and discussed. Keywords: Absorption heat pump, District heating system, Ammonia-water, Return temperature reduction, Exergetic efficiency