R134a中润滑油对强化管外池沸腾传热影响的实验研究

Experimental Study on Pool Boiling Heat Transfer of R134a-Oil Mixture Outside Single Horizontal Enhanced Tubes

对3根高效强化管（E21、E22、E23）在饱和温度为5℃和10℃的工况下进行了水平管外含油R134a池沸腾传热的实验研究．实验结果表明：相对于光滑管，强化管E21、E22和E23的管内传热系数强化倍率分别为3．703、3．035和2．709；在蒸发温度为5℃时，在不同的流速下，含油率为100X10。的外表面传热系数比含油率为50×10^-6的传热系数增加了3．7％～7．2％，而在10℃时增加了0．8％～10．9％．研究结果对于制冷系统中蒸发器的设计具有一定的参考作用．

In this study, heat transfer coefficients were experimentally determined for three horizontal enhanced tubes （E21, E22, E23） with R134a-oil mixture. The evaporation temperature was 10 ℃ and 5 ℃, respectively and the water velocity inside enhanced tubes was ranged from 1.5 m/s to 3.5 m/s. The results show that compared with smooth tube the enhancement magnification of heat transfer coefficient inside E21, E22 and E23 is 3. 703, 3.035 and 2. 709, respectively. The heat transfer coefficients outside the tubes with the oil concentration of 100 × 10^-6 increase by 3. 7%-7.2% compared with those with oil concentration of 50× 10^-6 at the same water velocities and the evaporation temperature 5 ℃, while by 0.8%-10.9% at the evaporation temperature 10 ℃.