Heat Transfer Enhancement Using R1234yf Refrigerants in Micro-Ribbed Tubes in a Two-Phase Flow Regime  

作　　者：Daoming Shen Xia Zhang Wei He Jinhong Xia Songtao Xue 

机构地区：[1]School of Civil Engineering&Architecture,Xinxiang University,Xinxiang,China [2]Department of Architecture,Tohoku Institute of Technology,Sendai,982-8577,Japan

出　　处：《Fluid Dynamics & Materials Processing》2020年第6期192-205,共14页流体力学与材料加工（英文）

基　　金：supported by the National Natural Science Foundation of China(No.41877251).

摘　　要：Experiments about heat transfer in the presence of a two-phase flow due to the condensation of a R1234yf refrigerant have been performed considering a smooth tube and two micro-fin tubes.The following experimental conditions have been considered:Condensation temperatures of 40℃,43℃ and 45℃,mass fluxes of 500–900 kg/(m^(2)·s),vapor qualities at the inlet and outlet of the heat transfer tube in the ranges 0.8–0.9 and 0.2–0.3,respectively.These tests have shown that:(1)The heat transfer coefficient increases with decreasing the condensation temperature and on increasing the mass flux;(2)The heat transfer coefficient inside the micro-fin tube is larger than that for the smooth tube;(3)The heat transfer enhancement factors for the micro-fin tube with a fin helical angle of 8°and 15°are 2.51–2.89 and 3.11–3.57,respectively;both are higher than the area increase ratio.These experimental results have been compared with correlations available in the literature:the Cavallini et al.correlation has the highest accuracy in predicting the heat transfer coefficient inside the smooth tube,the related percentage error and the average prediction error are±8%and 0.56%,respectively;for the micro-fin tube these become±25%and 6%,respectively.

关 键 词：R1234yf micro-ribbed tube heat transfer coefficient heat transfer enhancement factor 

分 类 号：TB6[一般工业技术—制冷工程]