【摘要】 混合制冷工质的传热性能差，使得其应用受到一定限制，而采用适当的强化传热技术可以大大提高混合制冷工质传热性能。实验的热流密度范围内，在相同的热流密度条件下，非共沸混合制冷剂Ｒ１３４ａ／Ｒ１４２ｂ在机械加工表面多孔管外沸腾传热膜系数是光滑管的１．７８～３．３３倍。更多还原

【Abstract】 It is well known that the nucleate boiling heat transfer coefficients of nonazeotropic mixtures on a plain tube is significantly low.The heat transfer enhancement technique should be adopted to improve the pool boiling heat transfer performance of refrigerants mixtures.The objective of the present paper is to obtain nucleate pool boiling heat transfer performance and mechanism for new refrigerants mixtures on processed porous tube as to determine the potential for application to refrigerants evaporator.The experiment result shows that the enhancement factor of nucleate boiling heat transfer coefficients on the machine processed porous tube is about 1.78～3.33 times size of that on a plain tube when comparing them at the same heat flux.更多还原