对氢氟碳化合物R-134a在光滑管和五个微英寸管中的蒸发传热进行了研究。用四种关联式对光滑管内的传热系数进行了比较。发现吉田关联式在环形流中最好，而Kandlikar关联式（FK=2.33）在分层流中最好，但后者需要澄清，因为FK值大导致的核沸腾效应强，因此其适用于低质量范围。为了确定最佳螺旋角，研究了微纤管螺旋角的影响。 在平均直径为8.71mm（0.343 in.）的恒定条件下，测试6、12、18、25和44度的螺旋角，和鳍的数量，60。发现最佳螺旋角主要取决于质量流量，质量流量为G=50 kg/m2·s（36865 lbm/ft2·h）时为18度，质量流量为G=100 kg/m2·s时为6度（73730 lbm/ft2·h），质量流量为G=200 kg/m·s时为6至18度（147460 lbm/ft2·h）。单位:双引证:研讨会，ASHRAE交易，1998年，第104卷，第2部分，多伦多

The in-tube evaporative heat transfer of the hydrofluorocarbon R-134a was examined for a smooth tube and five microfin tubes. The heat transfer coefficient in the smooth tube was compared with four correlations. The Yoshida correlation was found to be the best in annular flow, and the Kandlikar correlation with FK= 2.33 was the best in stratified flow, but the latter needs clarification for its applicability to the low quality range because of the strong nucleate boiling effect caused by the large value of FK. The effect of the spiral angle of microfin tubes was investigated to determine the optimal spiral angle. Spiral angles of 6, 12, 18, 25, and 44 degrees were tested at constant mean diameter, 8.71mm (0.343 in.), and number of fins, 60. The optimal spiral angle was found to be mainly dependent on the mass flux, and it was 18 degrees for a mass flux of G = 50 kg/m2·s (36,865 lbm/ft2·h), 6 degrees for G = 100 kg/m2·s (73,730 lbm/ft2·h), and 6 to 18 degrees for G = 200 kg/m ·s (147,460 lbm/ft2·h).Units: Dual