수평관 내 R-1234yf 응축 열전달 실험

Abstract

Due to environmental problems around the world, HFC refrigerants have been used instead of CFC and HCFC refrigerants with high ODP in the field. But, these refrigerants are also subject to regulation due to their high GWP. Accordingly to cope with the phased regulatory planning of HFC refrigerants, related companies have developed HFO refrigerants with low GWP. Among HFO refrigerants, the working fluid R-1234yf (GWP:4) in this paper is similar in thermodynamic properties to R-134a (GWP:1300). The experiment results are summarized as follows. The condensation heat transfer coefficient of R-1234yf in the double tube heat exchanger increased with increasing mass flux and quality. The condensation heat transfer coefficient decreased with increasing saturation temperature, but at high mass flux and high quality, it had little effect on saturation temperature. As the temperature difference between the coolant and the refrigerant increased, the heat transfer coefficient tended to increase. The condensation heat transfer coefficient of R-1234yf is lower than that of R-134a in almost all quality. However, at low quality and low mass flux the condensation heat transfer coefficient of R-1234yf tended to be greater than R-134a. Due to the difference in refrigerant physical properties such as density, surface tension, and thermal conductivity of the two refrigerants. As a result, it is believed that this paper could be used as a foundation for the optimal design of condensers using R-1234yf.