竖直圆管外含空气蒸汽冷凝传热的实验研究

摘要

By carrying out experimental study on the condensation of steam with air on the outer wall of a vertical pipe ,the effects of mass fraction of air ,pressure and subcooling on steam condensation were analyzed ,and the empirical correlations of condensation heat transfer of steam with the air were given .The results show that under the same air mass fraction and pressure conditions , the effect of wall subcooling on condensation heat transfer coefficient is greater than that of the pure steam condensation given by Nusselt laminar solution .The empirical correlation obtained is suitable for a wider application region and the correlation error associated with the experimental value is within ± 10% .%通过对含空气蒸汽在竖直圆管外表面冷凝传热的实验研究，分析了空气质量分数、压力及过冷度对蒸汽冷凝换热的影响，给出了含空气蒸汽的冷凝传热过程中的实验关联式。结果表明：在空气质量分数及压力不变的条件下，壁面过冷度对冷凝传热系数的影响高于纯蒸汽冷凝过程中的N usselt层流解；所得到的实验关联式具有更广的适用范围，且其与实验值的误差在±10％以内。