摘要
在一个单级压缩制冷循环系统中研究了蒸发式冷凝器管外水膜的传热性能。建立了蒸发式冷凝器管外水膜传热性能测试实验平台，调节不同操作参数，测试了喷淋密度和迎面风速对管外水膜传热性能的影响。结果表明，在实验条件下，管外水膜传热系数的实验值介于511．6～763．57W·m^-2·K^-1。喷淋密度从0．023kg·m^-1·s^-1增至0．059kg·m^-1·s^-1和迎面风速从2．1m·s^-1增至3．3m·s^-1，实验条件下管外水膜传热系数的平均变化率分别为增加47．3％和减少5．5％，可见，管外水膜的传热主要受喷淋密度的影响。另外，通过对实验数据回归得到了管外水膜传热系数计算关联式，回归相关系数R为0．98，标准偏差为7．5％。最后，将实验关联式和国内外学者的关联式进行比较，表明实验得出的管外水膜传热系数计算关联式具有较好的一致性。管外水膜传热性能的实验结果对蒸发式冷凝器的设计和实际应用具有一定的指导意义。
Using a single-stage compressed refrigeration cycle system, the heat transfer performance of the water film on the condensing coils of the evaporative condenser was studied. The effects of the spray density and the head-on air velocity on the heat transfer performance of the water film were investigated under various operation conditions. The experiments were conducted under spray density range of 0.023-0.059 kg·m^-1·s^-1 and the head-on air velocity range of 2.1-3.3 m·s^-1, and the results show that the heat transfer coefficient of the water film αw increases with the increase of spray density and decreases with the increase of head-on air velocity. When the spray density and head-on air velocity vary in above mentioned ranges, the αw increases 47.3%, and decreases 5.5%, respectively, it indicates that the key factor affecting the heat transfer of the water film is the spray density. In addition, via regression analysis of the experimental data, the correlation equation for calculating the heat transfer coefficient of the water film was obtained, its regression correlation coefficient R is 0.98 and the standard deviation is 7.5%. Finally, the correlation equation obtained was compared with some other relative correlations obtained from literatures, and it shows in concordance with them. In general, the obtained experimental results of the water film heat transfer are helpful to the design and practical operation of the evaporative condensers.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2007年第1期31-36,共6页
Journal of Chemical Engineering of Chinese Universities
基金
广东省自然科学基金(04105950)
顺德区重点科技计划(2003KJ027)
2005年新世纪优秀人才计划
关键词
蒸发式冷凝器
水膜
传热
喷淋密度
evaporative condenser
water film
heat transfer
spray density
