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实验研究了R152a在内径为1.152 mm不锈钢圆管内的凝结换热特性。实验饱和温度为40～50℃,质量流速为200～1200 kg/(m~2·s),干度为0.1～0.9。研究了质量流速和干度、饱和温度、热流密度以及倾斜角度对换热系数的影响。结果表明换热系数随质量流速和干度的增大而增大,随饱和温度和热流密度的降低略有增强;倾斜角度对换热的强化作用体现在低质量流速区。与已有的换热关联式进行了对比,偏差普遍较大;修正了一个换热关联式,修正后偏差在±30%以内。
The condensation heat transfer characteristics of R152a in a 1.152 mm stainless steel tube were experimentally studied. The experimental saturation temperature is 40 ~ 50 ℃, the mass flow rate is 200 ~ 1200 kg / (m ~ 2 · s), the dryness is 0.1 ~ 0.9. The effects of mass flow rate and dryness, saturation temperature, heat flux density and inclination angle on the heat transfer coefficient were investigated. The results show that the heat transfer coefficient increases with the increase of the mass flow rate and dryness, slightly increases with the decrease of the saturation temperature and the heat flux. The strengthening effect of the inclination angle on the heat transfer is reflected in the low mass flow rate. Compared with the existing heat-exchange correlation, the deviations are generally large; a heat-exchange correlation is corrected, and the corrected deviation is within ± 30%.