4E analysis and field test of high temperature heat pump with low GWP refrigerant for industrial heating

The high temperature heat pump (HTHP) plays an important role in improving the efficiency of electric heating and thereby achieving a peaking and then reduction of global carbon emissions. Applications of HTHP in industrial heating is able to replace the boilers directly. Refrigerant has significant impact on system performance and then the efficiency of industrial heating. Low global warming potential (GWP) refrigerants R600, R601, R601a, R1224yd(Z), R1233zd(E), R1234ze(Z) and R1336mzz(Z) were selected and compared with R245fa. The two-stage compression HTHP system model was established. Energy, exergy, environment, and economy analysis with different refrigerants were conducted. R601, R601a, and R1233zd(E) have significant advantages over R245fa when the evaporation temperature is 50°C and condensation temperature is 100∼130°C. When the condensation temperature is 130°C, compared with R245fa, coefficient of performance ( COP ) of R601, R601a and R1233zd(E) increased by 11.08%, 9.14% and 6.14%, respectively. Exergy efficiency increased by 8.71%, 7.24% and 4.77%, respectively. Total equivalent warming impact ( TEWI ) decreased by 10.42%, 8.83% and 6.25%, respectively. Investment payback period ( PBP ) shortened by 69.73%, 65.93% and 40.12%, respectively.