摘要
实验研究了环保替代制冷工质R410A-润滑油混合物在水平直光管内的流动沸腾换热特性.实验测试管长度2m、外径7mm.实验工况的蒸发温度为5℃,质量流率为200-400kg/(m^2·s),热流密度为7.56~15.1kW/m^2,入口干度x=0.2~0.7,干度变化为0.2,油的平均质量分数wno=0~5%.实验结果表明,R410A-油混合物管内流动沸腾的换热系数随质量流率的增大而增大;在x〈0.7的工况下,油的存在总是增大换热,当wno从0增长到5%时,换热系数最大可增加61%.在x=0.8的高干度情况下,换热系数在wno=1%时达到最大值,然后随着wno的增大换热系数逐渐降低.
Experimental study of the heat transfer characteristics of R410A-oil mixture flow boiling in a horizontal smooth tube was performed to investigate the influence of oil concentration, vapor quality and mass flux on the heat transfer coefficient. The length of the test tube is 2 000 mm, and the outside diameter is 7.0 mm. The experimental parameters include the evaporating temperature of 5℃, the mass flux from 200 to 400 kg/(m^2· s), the heat flux from 7.56 to 15. 1 kW/m^2 , the inlet vapor quality from 0. 2 to 0.7, and oil concentration from 0 to 5%. The test result shows that the heat transfer coefficient of the R410A-oil mixture increases with the mass flux; the presence of oil enhances the heat transfer coefficient when the vapor quality is less than 0. 7; the heat transfer coefficient can be enhanced by 61% as the oil concentration increases from 0 to 5%. When the vapor quality is 0.8, the heat transfer coefficient gets the maximum value at the oil concentration of 1%, and then it decreases with the increasing of oil concentration.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2007年第10期1633-1637,共5页
Journal of Shanghai Jiaotong University
基金
教育部新世纪优秀人才支持计划资助项目([2005]290)