摘要
对非共沸混合工质R32 /R134a的管内流动凝结局部换热系数进行了理论分析和计算 .计算表明 ,非共沸混合工质的管内流动凝结换热系数总是低于具有等同物性的纯工质的换热系数 ,其换热系数下降的程度不仅受浓度的影响 ,还受干度的影响 .对混合工质R32 /R134a而言 ,换热系数的极小值出现在R32质量分数为10 %～ 30
A theoretical approach to forced convective condensation heat transfer coefficient of nonazeotropic mixtures inside smooth tubes was developed. Calculations were performed for R32/R134a mixtures with the R32 mass fraction ranged from 0 to 60.1%. The results reveals that there is a reduction of heat transfer coefficient for a nonazeotropic mixture compared with that of a single component substance with the same thermophysical properties. The reduction of the heat transfer coefficient depends not only on the mass fraction of the mixture, but also on the vapor quality of the fluid. Besides, minimum heat transfer coefficients were observed at mass fractions ranging from 10% to 30% for R32/R234a mixtures.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2001年第2期114-117,共4页
CIESC Journal
