Performance prediction of HFC, HC, HFO and HCFO working fluids for high temperature water source heat pumps

Abstract

High temperature water source heat pumps (HTWSHP) plays an increasingly important role in drying and building heating due to its remarkable energy-saving effect. However, traditional heat pump working fluids such as R134a are not applicable for HTWSHP and the research on alternative working fluids is limited by the complex process of working fluids screening. This paper is aimed to quickly and easily obtain the performance of a large amount of working fluids for screening. A new simple performance predicted model was proposed in a simple vapor compression cycle at condensation temperatures from 70 to 110 °C. By knowing only a working fluid’s critical temperature and pressure, the specific volumetric heating capacity (VHC) and coefficient of performance (COP) can be predicted. Based on the model, the performance prediction for the newer working fluids involving R1336mzz(Z) and R1224yd(Z) was conducted. The results produced by the model were compared with the values calculated by Peng-Robinson equation of state (PR EoS) and the default, high-accuracy equations implemented in REFPROP 10.0. The predicted values in this work show good agreement. Besides, the model can also be applied varying compressor isentropic efficiencies from 60% to 80%, superheats from 0 to 10 °C and sub-coolings from 0 to 8 °C.