R410A在单管外池沸腾换热的理论及实验研究

Theoretical and experimental study on pool boiling heattransfer of R410A outside a single tube

在节能与环保双重压力下,研究高效换热器成为节能减排的一个重要方向。实验利用单管换热装置,研究在不同工况下,R410A在1根光管和3根双侧强化螺纹管外的池沸腾换热特性。结果表明:在实验研究范围内,提高R410A饱和温度更利于换热;换热管EX1和TLC的总换热系数分别是光管的1.82和1.74倍,EX1的总换热系数相比TLC提高5%,不同微肋结构中换热管EX1换热能力更好;在不同管径换热管中,EX2的水侧换热系数高于EX1,而EX1的制冷剂侧换热系数高于EX2;通过热阻分析可知,随着雷诺数的增大,制冷剂侧热阻是换热管强化的重点。

Under the pressure of energy conservation and environmental protection,the study of high-efficiency heat exchangers become an important direction for saving energy and reducing emission.The characteristics of pool boiling heat transfer of R410A outside a smooth tube and three double-sided reinforced threaded tubes under different working conditions were studied by using a single tube heat transfer experimental device.The results show that increasing the saturation temperature of R410A can improve heat transfer within the experimental research scope.The total heat transfer coefficients of heat exchange tubes EX1 and TLC are 1.82 and 1.74 times those of bare tubes,respectively.The total heat transfer coefficient of EX1 is 5%higher than that of TLC.The heat transfer capacity of heat exchange tubes EX1 with different micro-rib structures is better.In different pipe diameters,the water side's heat transfer coefficient of EX2 is higher than that of EX1,while the refrigerant side coefficient is contrary.The thermal resistance analysis shows that with the increase of the Reynolds number,the thermal resistance of refrigerant side is the focus of heat transfer tube enhancement.