R410A和R134a在水平强化管内的冷凝换热性能  

Condensation Heat Transfer Performance of R410A and R134a in Horizontal Enhanced Tubes

作　　者：毛舒适 陶乐仁[1] 李庆普[1] 吴生礼 MAO Shu-shi;TAO Le-ren;LI Qing-pu;WU Sheng-li(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,China,200093)

机构地区：[1]上海理工大学能源与动力工程学院

出　　处：《热能动力工程》2019年第11期75-81,共7页Journal of Engineering for Thermal Energy and Power

基　　金：上海市动力工程多相流动与传热重点实验室开放基金(13DZ2260900)~~

摘　　要：为研究强化管的冷凝换热性能和强化换热机理,采用实验的方法对R410A在外径6.35和8 mm的光管及内螺纹管(螺旋角为18°和28°)中的冷凝换热性能进行了研究,并与R134a进行对比,实验工况:冷凝温度30和35℃,质量流速400~1 100 kg/(m^2·s)。结果表明:螺纹管冷凝传热系数强化倍率均显著大于内表面扩展倍率;R134a强化因子大于R410A,强化管对粘度、表面张力较大的制冷剂强化效果更显著;8 mm管强化因子大于6 mm,管径较大时,换热提升效果更好;水侧雷诺数为14 000时,8 mm、28°螺纹管在质量流速为500 kg/(m^2·s)时,管内外侧热阻接近,强化效果较好。To investigate the condensing heat transfer performance of the enhanced tube and the mechanism of enhanced heat transfer,the condensation heat transfer performance of R410 A inside 6.35 and 8 mm ID smooth tubes and inner-grooved tubes(the helix angle is 18° and 28° respectively) was studied by experiments and compared with R134 a.The experimental conditions are as follows.The condensing temperature is 30 and 35 ℃ and the mass flow rate is 400~1 100 kg/(m^2·s).The experimental results show that enhancement ratios of the heat transfer coefficient of the inner-grooved tube are significantly larger than the expansion ratios of inner surface area.The enhancement factor of R134 a is greater than R410 A,that is,the effect of enhanced tube on the refrigerant whose viscosity and surface tension are larger is more significant.The enhancement factor of 8 mm tube is greater than 6 mm tube,that is,the heat transfer enhancement effect is larger for larger diameter.When the Reynolds number of the water side is 14 000 and the mass flow rate of the 8 mm tube with a helical angle of 28 is 500 kg/(m^2·s),the thermal resistance of the tube inside is close to the outside,and the strengthening effect is better.

关 键 词：内螺旋管 传热系数 强化传热 热阻分析 综合性能评价 

分 类 号：TK124[动力工程及工程热物理—工程热物理]