【摘要】 为制冷工质应用于家用空调的蒸发器优化设计提供依据,在质流密度100—300 kg/(m~2·s)、热流密度10—20 kW/m~2、饱和温度287.15—291.15 K、平均干度0.1—0.9的实验条件下,研究近共沸混合工质R152a/R1234ze(E)(质量比为3∶2)在水平光滑管(内径4 mm)内的沸腾传热特性。分析上述实验条件对该混合工质的沸腾传热系数和临界干度的影响。结果表明:沸腾传热系数随质流密度、热流密度、饱和温度的增加而增大,而随平均干度的增加呈现先增大后减小的变化趋势;此外,临界干度随质流密度的增加而增大,随热流密度的增大而减小。并用4种经典沸腾传热关联式预测了该混合工质的沸腾传热系数,对比实验结果发现Fang等和Choi等的预测精度较高,其平均绝对误差分别为10.63%和24.39%。更多还原

【Abstract】 Aiming to provide a basis for the optimal design of evaporators for domestic air conditioning applications, the boiling heat transfer characteristics of the near azeotropic mixture R152a/R1234ze(E)(3/2 by mass)in a horizontal smooth tube(with an inner diameter of 4 mm)were investigated, under the experimental conditions of mass flux of 100-300 kg/(m~2·s), heat flux of 10-20 kW/m~2, saturation temperature of 287.15-291.15 K, and the average vapor quality of 0.1-0.9. The effects of the above experimental conditions on the boiling heat transfer coefficient and the critical vapor quality were analyzed. The results show that the boiling heat transfer coefficient increases with the increase of mass flux, heat flux, and saturation temperature, while it shows a trend of increasing first and then decreasing with the increase of average vapor quality. Moreover, the critical vapor quality increases with mass flux increasing, and decreases with heat flux increasing. Then, the boiling heat transfer coefficients of the mixture were predicted by four classical boiling heat transfer correlations.The results reveal that the predicted accuracy of Fang et al. and Choi et al. are higher, and the average absolute deviations are 10.63% and 24.39%, respectively.更多还原