摘要
研究非共沸混合工质R32/R134a(质量比,25%/75%)在水平微尺度通道内流动沸腾换热规律。在各种工况下进行了非共沸混合工质R32/R134a在水平微尺度管道内流动沸腾换热的实验,考察了质量流量G、热流密度q、质量干度x对微尺度通道内流动沸腾换热系数的影响。研究表明:在热流密度、质量流量都较低的区域,对细管道,换热系数与热流密度的关联度较大;而对微管道,换热系数受影响的因素比较多,并在干度为0.6时出现"干涸"现象,使得换热系数急剧下降。在质量流量高的区域,对细管道,热流密度对换热系数的影响很小;而对微尺度管道,当干度为0.06时换热系数发生转变,随质量干度的增加先减小后增大,热流密度增大到一定的阶段后,换热系数不再随热流密度变化。
Mechanism of flow boiling heat transfer in horizontal micro-scale tube with non-azeotropic refrigerant mixture R32/R134a （25%/75% wt.） is studied in this paper. Experimental research is carried out for flow boiling heat transfer with R32/R134a in micro-scale tube and mini-scale tube. The influence of mass flow rate G, heat flux q and mass quality x on the local heat transfer coefficients are observed. In the low heat flux density and low mass flow area, the heat transfer coefficient and heat flux is relative large for the mini-scale tube; while the micro-scale tube heat transfer coefficients are more affected by many factors, and a ＂dried up＂ phenomenon appears When the mass quality was 0.6, making heat transfer coefficient dropped sharply. In areas of high mass flow of mini-scale tube, heat flux has little effect on heat transfer coefficient; and for the micro-channel, when the quality is 0.06, the heat transfer coefficient decrease first and then increase with the increase of quality. Heat transfer coefficients remain basically unchanged when the heat flux increases to a certain stage.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2010年第12期2083-2086,共4页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.50876068)
关键词
微尺度通道
流动沸腾
混合物
micro-scale channel
flow boiling
refrigerant mixture
