R1234ze和R22在微细通道中流动凝结换热的实验研究

Experimental Investigation on Heat Transfer of R1234ze and R22 During Condensation in Minichannels

实验研究了R1234ze、R22在细圆管中的流动凝结换热特性。实验圆管内径为1.085 mm,方管为0.952 mm。R22的质量流率为200~1200 kg/(m^2·s),R1234ze的为200~800 kg/(m^2·s),饱和温度为40℃与50℃。实验结果表明,高质量流率时R22在较高干度下换热系数随干度增加缓慢或略有下降,R1234ze的随干度变化有较明显的线性性质。相同条件下R1234ze的凝结换热系数高于R22的。对比实验结果与现有关联式的预测结果,其中,Wang等关联式(2002)对实验数据预测偏差在21%之内,Kim等关联式(2013)对实验数据预测偏差在19%之内。

Heat transfer characteristics of R1234ze and R22 during condensation were experimentally investigated in a 1.085 mm circular minichannel and a 0.952 mm square minichannel.Tests were conducted with saturation temperatures of 40℃ and 50℃,mass fluxes of 200-1200 kg/（m^2·s） for R22 and 200-800 kg/（m^2·s） for R1234ze.The results show that the heat transfer coefficients of R22 increase slowly even decrease with increasing vapor quality for high mass fluxes and vapor qualities.The heat transfer coefficients for R1234ze approximately increase linearly with increasing the vapor quality.The heat transfer coefficients of R1234ze are higher than those of R22.The comparison of the experiments with the predictions shows that the deviations are within 21% for the Wang et al.correlation（2002） and 19% for the Kim et al.correlation（2013）.