A multistage heat pump unit model for reducing energy consumption of space heating at low ambient temperatures

Abstract

Air heat pump units (HPUs) for space heating are used more widely than geothermal ones, mainly due to lower installation costs. The main disadvantages of geothermal installations are their low productivity and coefficient of performance (COP). In this work, a multistage heat pump unit with an air source was modeled, which lead to reduce in the energy consumption of the compressors in all of the HPU stages at an ambient temperature of -30 ° C and a heating temperature from 20 ° C to 65 ° C. Wherein, the COP of the modeled multistage HPU in all modes is 20% higher in comparison with a two-stage HPU considered in the literature review. In addition, the influence of the decrease in the ambient temperature on the increase in the energy consumption of the first stage of a multistage HPU was presented in this work.