Performance analysis of a R407C liquid-to-water heat pump: effect of a liquid–vapor heat exchanger and domestic hot water production

Abstract

This paper presents an experimental study of a R407C liquid-to-water heat pump for combined space heating (SH) and domestic hot water (DHW) production. The main components of the heat pump are a scroll compressor, a desuperheater for DHW production, two brazed plate heat exchangers (condenser and evaporator) and a thermostatic expansion valve. A liquid–vapor heat exchanger (LVHEx) has been included in order to study its effect on the heat pump performance. Experimental results for typical operating conditions in the heating mode of operation (low and medium temperature applications) are presented and discussed. These operating conditions are combined with simultaneous DHW production at different flow rates and temperature values. Results show that, in general, the COP is higher with simultaneous SH and DHW production than with SH alone. Also, using the LVHEx yields lower heating and compression powers and, in general, slightly lower COP values.