水平圆管内R1234yf流动冷凝传热特性研究  

Research on R1234yf flow condensation heat transfer characteristics in horizontal tube

作　　者：齐创 李瑛[1] 张良[1] 齐昊 QI Chuang;LI Ying;ZHANG Liang;QI Hao(Shanghai Key Laboratory of Multiphase Flow and Heat Transfer of Power Engineering,School of Energy and Power Engineering,University of Shanghai for Science and Technology,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市动力工程多相流动与传热重点实验室,上海200093

出　　处：《化学工程》2022年第8期46-50,共5页Chemical Engineering(China)

基　　金：上海市部分地方院校能力建设专项计划(16060502600)。

摘　　要：为了将低GWP制冷剂应用于客车空调,对R1234yf在5 mm水平光滑管内的流动冷凝传热特性进行了实验研究。实验研究工况为饱和温度30℃和40℃,平均干度0.1—0.96,质量流速100—600 kg/(m^(2)·s)。研究结果表明:R1234yf管内传热系数在低质量流速[<200 kg/(m^(2)·s)]下受干度和流速的影响不明显,随着流速的增大逐渐依赖蒸汽流速和干度,这表明管内主要传热机制由受温差较大影响的自然对流过渡至受流速影响较大的强制对流,引入了等效雷诺数Re_(eq)来划分这2种传热机制。饱和温度为30℃时,相同工况下R1234yf传热系数比R134a低3.7%—14.3%。对Cavallini和Bashar 2种关联式预测的传热系数与实验值进行了对比,Bashar关联式表现出较好的预测效果,平均绝对偏差为14%。In order to apply low GWP refrigerant to passenger car air conditioners,the flow condensation heat transfer characteristics of R1234 yf were studied experimentally in a 5 mm horizontal smooth tube.The experimental conditions are as follows:saturation temperature 30 ℃ and 40 ℃,vapor quality 0.1-0.96 and mass flux 100-600 kg/(m^(2)·s).The research results show that the heat transfer coefficient of R1234 yf is not significantly affected by the vapor quality and mass flux at low mass fluxes [less than 200 kg/(m^(2)·s)],and gradually depends on the vapor flow velocity and vapor quality in the tube as the mass flux increases.This indicates that the main heat transfer mechanism in the tube transitions from free convection,which is greatly affected by the temperature difference,to forced convection,which is greatly affected by the flow velocity.The equivalent Reynolds number Re_(eq) is introduced to divide the two heat transfer mechanisms.When the saturation temperature is 30 ℃,the heat transfer coefficient of R1234 yf is 3.7% to 14.3% lower than that of R134 a under the same working condition.The heat transfer coefficients predicted by Cavallini and Bashar correlations were compared with the experimental datas.The Bashar correlation shows a better prediction effect,with an average absolute deviation of 14%.

关 键 词：R1234yf 流动冷凝传热机制 传热系数 关联式预测 

分 类 号：TH12[机械工程—机械设计及理论] TB61.2[一般工业技术—制冷工程]