二氧化碳直接蒸发冰场排管内流动沸腾换热数值模拟分析

Numerical simulation of flow boiling heat transfer in pipe arrays of carbon dioxide direct evaporation ice field

为探究二氧化碳直接蒸发室内冰场的传热特性,对二氧化碳在内径为11.00 mm以及13.47 mm的水平光滑管进行计算流体力学模拟分析。分析了质量流速、热通量、管径以及干度等因素对二氧化碳在水平光滑管中的流动沸腾换热特性的影响。计算结果表明:在CO_(2)室内冰场工况下,质量流速、热通量等参数的提升能够增强换热性能。对已有的换热关联式进行修正,使其能够适用于大管径工况,并将新关联式计算出的结果与文献中的实验数据进行对比,结果显示新的换热关联式关联性较好。分析了大管径工况下制冷剂含油对传热系数的影响因子。对于二氧化碳直接蒸发室内冰场的优化设计具有参考价值。

In order to investigate the heat transfer characteristics of the direct evaporation of carbon dioxide indoor ice rink,the computational fluid dynamics simulation of carbon dioxide in horizontal smooth tubes with inner diameters of 11.00 mm and 13.47 mm was carried out.The effects of mass flow rate,heat flux,pipe diameter and dryness on the flow boiling heat transfer characteristics of carbon dioxide in horizontal smooth tubes were analyzed.The calculation results show that under the working condition of CO_(2) indoor ice rink,the improvement of mass flow rate,heat flow density and other parameters can enhance the heat transfer performance.The existing heat transfer correlation was modified to make it suitable for large pipe diameter conditions.The results calcalated by the new correlation was compared with experimental data from literatures,and the results showed that the new heat exchange correlation had good correlation.The influence factors of refrigerant oil content on heat transfer coefficient under the condition of large pipe diameter are analyzed.This paper has reference value for the optimization design of indoor ice rink for direct evaporation of carbon dioxide.