HFC-32/HFC-134a和HCFC-22在水平管内的强制对流沸腾换热特性

Forced convective boiling heat transfer characteristics of HFC 32/HFC 134a and HCFC 22 in a horizontal tube

进行了非共沸混合制冷剂ＨＦＣΑ３２／ＨＦＣΑ１３４ａ和纯制冷剂ＨＣＦＣΑ２２在水平管内的强制对流沸腾换热实验．ＨＦＣΑ３２的质量分数为０．１０、０．２５和０．４０，热流密度为６、１２、１８、２４、３６、４８和６０ｋＷ／ｍ２，质量流量为１０、１５、２２、３０和４６ｇ／ｓ，实验段进口压力保持为０．４ＭＰａ．实验结果表明在质量流量大于２２ｇ／ｓ时，ＨＦＣΑ３２／ＨＦＣΑ１３４ａ的换热系数与ＨＣＦＣΑ２２相当．实验对混合制冷剂的强制对流蒸发换热退化、核态沸腾抑制和环状流周向壁温分布等现象进行了分析．采用Ｊｕｎｇ关系式的预测值与本文实验结果比较。

An experimental study on forced convective boiling heat transfer for a refrigerant mixture of HFC 32/HFC 134a and HCFC 22 in a horizontal smooth tube is reported at several compositions.The ranges of heat flux and mass flow rate are 10～50kW/m 2 and 10～46g/s,respectively.A number of special phenomena are discovered,such as the reversal distribution of peripheral wall temperature and local heat transfer coefficients,suppression of nucleate boiling,and so on.The measured heat transfer coefficients are compared with the correlation of Jung,the average deviation being ±25%.