Low GWP 냉매의 응축열전달 및 압력강하 특성

Due to the concerns of the global warming, many countries are strictly tightening the regulations about greenhouse gases. In case of refrigeration system, there are many ongoing researches on low GWP refrigerants. GWP refers to a measure of how much the given substance can give effect on the global warming. In this study, condensation heat transfer and pressure drop of various low GWP refrigerants like R-1234yf and R-1234ze(E) in plate heat exchangers are investigated. The condensation heat transfer and pressure drop characteristics for each low GWP refrigerant are reviewed. The comparisons of experimental correlations equations for condensation heat transfer and pressure drop will be carried out. From the comparison, it is concluded that the heat transfer coefficients of R-1234yf and R-1234ze(E) are lower than those of R-134a, while R-1234ze(Z) gives much higher condensation heat transfer coefficient than R-134a. It is also concluded that R-1234ze(E) and R-152a give higher frictional pressure drop than R-134a, but R-1234yf give lower value.