R513A在水平管内流动沸腾传热特性的研究  

Experimental Study on Flow Boiling Heat Transfer Characteristics of R513A Inside Horizontal Tubes

作　　者：朱天意 黄理浩[1,2] 陶乐仁 Zhu Tianyi;Huang Lihao;Tao Leren(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,200093,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai,200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《制冷学报》2024年第5期137-144,共8页Journal of Refrigeration

基　　金：上海市动力工程多相流动与传热重点实验室项目(13DZ2260900)资助。

摘　　要：全球变暖已成为各国关注的全球性问题,因此第4代新型环保制冷剂的研究迫在眉睫。制冷剂在蒸发器内的沸腾传热特性直接关系到该制冷剂的应用。R513A是R134a的替代制冷剂,通过实验研究R513A和R134a在12.7 mm水平光滑管和内螺纹管内的沸腾传热特性,分析质量流速、蒸发温度、热流密度和内螺纹结构对传热系数及压降变化的机理。实验工况:制冷剂的质量流速为100~200 kg/(m^(2)·s),蒸发温度为5~10℃。结果表明:沸腾传热系数随着热流密度的增大发生显著变化;随着质量流速的增加,沸腾传热系数增大15.06%~42.33%,压降增大26.16%~61.83%;随着蒸发温度升高,沸腾传热系数增大13.27%~38.25%,压降减小19.53%~33.27%;内螺纹管的传热系数显著高于光滑管,强化倍率最大为2倍。相同工况下,R513A的沸腾传热系数比R134a增大约25.61%~30.74%,R134a内螺纹管内压降比R513A平均高约12.33%;随着热流密度的增加,R513A的流型转变较R134a提前,此时沸腾传热系数急剧下降。Global warming has emerged as a world-wide concern;therefore,research on the fourth generation of new environmentally friendly refrigerants is an urgent requirement.The boiling heat transfer characteristics of a refrigerant in an evaporator are directly related to its application.Thus,the R513A refrigerant is a suitable alternative to R134a.The boiling heat transfer characteristics of R513A and R134A in a 12.7 mm horizontal smooth tube and microfin tube were experimentally studied.The effects of mass flow rate,evaporation temperature,heat flux,and internal thread structure on heat transfer coefficient and pressure drop were also analyzed.The experimental mass flow rate of refrigerant was 100-200 kg/(m^(2)·s)and the evaporating temperature was 5℃-10℃.The results showed that the boiling heat transfer coefficient changed significantly with an increase in the heat flux.With an increase in mass flow rate,the boiling heat transfer coefficient increased by 15.06%to 42.33%,and the pressure drop increased by 26.16%to 61.83%.As the evaporating temperature increased,the boiling heat transfer coefficient increased by 13.27%to 38.25%,and the pressure drop decreased by 19.53%to 33.27%.The heat transfer coefficient of the microfin tube was significantly higher than that of the smooth tube,with a reinforcement multiplier of up to 2.Under the same conditions,the boiling heat transfer coefficient of R513A was 25.61%-30.74%higher than that of R134a.The pressure drop inside the microfin tube of R134a was approximately 12.33%higher than that of R513A.With an increase in the heat flux,the flow pattern transition of R513A occurred earlier than that of R134a,and the boiling heat transfer coefficient decreased sharply.

关 键 词：内螺纹管 流动沸腾 传热系数 摩擦压降 R513A 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TB611[动力工程及工程热物理—热能工程]