Condensation heat transfer characteristics of R513A in horizontal tubes
R513A is the fourth-generation new environmentally friendly refrigerant,which has wide application prospects in refrigeration and air conditioning.In order to study the condensation heat transfer characteristics of R513A in horizontal tubes,a set of experimental device was set up for condensing/evaporating integrated heat transfer in horizontal single tube.The condensation tests were conducted at condensation temperature of 33,35,38,40℃,refrigerant mass flux range 50-225 kg/(m2·s).The condensation heat transfer coefficient and pressure drop of R513A were studied in double tubes with variable mass fluxes and condensation temperatures.Then the results were compared with the condensation heat transfer coefficients and pressure drops of R32 and R134a.The experimental results show that the condensation heat transfer coefficients and pressure drops of R513A increase with the increase of mass flux,but decrease with the increase of condensation temperature.The condensation heat transfer performance of R32 is better than that of R513A and R134a,and the condensation heat transfer coeffiicient of R134a is 19.7％higher than that of R513A.But the pressure drop of R134a is 49.2％higher than that of R513A.Overall,R513A could be proposed as alternative to R134a.Finally,experimental data were also compared with several correlations proposed for smooth and micro-fin tube.The correlations from Dobson and Chato,and Cavallini et al have a better prediction accuracy and the mean absolute deviations are about 13.2％and 13.62％,respectively.
condensation heat transferpressure dropR513Aheat transfer correlation
万方数据
维普
