微细通道内CO_(2)流动沸腾换热数值模拟分析  

Numerical Simulation Analysis of the Boiling Heat Transfer Characteristics of CO_(2) Flow Inside a Micro-channel

作　　者：姬旭 杨俊兰 李金芮 白杨 JI Xu;YANG Junlan;LI Jinrui;BAI Yang(School of Energy and Safety Engineering,TCU,Tianjin 300384,China)

机构地区：[1]天津城建大学能源与安全工程学院,天津300384

出　　处：《天津城建大学学报》2022年第4期267-272,共6页Journal of Tianjin Chengjian University

基　　金：天津市自然科学基金项目(17JCZDJC31400)。

摘　　要：为了研究CO_(2)工质在微细通道内流动沸腾换热特性,采用Fluent软件建立模型,通过给定边界条件模拟分析了CO_(2)沸腾换热,与已有的换热关联式进行对比分析.结果表明:低干度下的相对误差在15%以内,验证了模型的准确性.根据液相容积分配图,在低干度条件下,随着饱和温度和热流密度的增大,通道内气泡的数量增多,尺寸明显增大,说明CO_(2)沸腾换热系数增大;质量流速对沸腾换热系数的影响较小,从而也说明了在低干度区,CO_(2)核态沸腾机理占主导地位.To study the boiling heat transfer characteristics of CO_(2)flow in a microchannel,the researchers used the Fluent software to establish a model.The CO_(2)flow boiling heat transfer was simulated and analyzed by the given boundary conditions,and was compared with the existing heat transfer correlations.The results show that the relative error under low dryness is less than 15%,which verifies the accuracy of the model.According to the distribution graph of liquid volume,under the condition of low dryness,with the increase of saturation temperature,heat flux density,the number and size of bubbles in the channel increase significantly,which indicates that the boiling heat transfer coefficient of CO_(2)flow increases;the mass flow rate has little effect on the boiling heat transfer coefficient.It is also shown that the nucleate boiling mechanism of CO_(2)is dominant in the low dryness region.

关 键 词：二氧化碳 沸腾换热 气液两相流 数值模拟 微通道 

分 类 号：TK124[动力工程及工程热物理—工程热物理]