Theoretical and Experimental Analysis of the Superheating in Heat Pump Compressors

In a conventional cooling system, refrigerant superheating inside the compressor is largely responsible for overall energy losses, increasing the compression specific work and decreasing the cooling capacity. In heat pump applications, superheating not only affects the compression loss, but also the specific heating capacity of the system, since the inlet temperature of the condenser depends on the final temperature of compression. Kremer et al. (2011) proposed a new approach to identify and understand the superheating losses in compressors submitted to heat pump applications. In this paper, a more accurate approach is proposed and the effects of refrigerant superheating are analyzed using a compressor thermal model. Different configurations of compressors are experimentally and numerically evaluated in order to validate the theoretical model. The obtained results follow the trend established by the theoretical purpose.