湿热地区运行参数对波纹翅片管换热器性能的影响研究

鉴于波纹翅片管换热器热湿工况运行优化缺少指南,建立了某9排管空气-水逆流式波纹翅片管换热器的传热除湿数学模型,利用MATLAB编程开展仿真,试验验证了仿真结果之后,在广州和杭州2种湿热气候条件下,探究了水流速度、风速以及进口水温对换热器换热、除湿性能的影响规律。结果显示:风速对换热量影响最大,进口水温对除湿量影响最大;在相同的水温、水速和风速下运行,在广州换热量与除湿量分别比在杭州高23.7%~44.1%和33.5%~64.3%,且几乎不随风速变化而变化,随水温降低高出的比例线性增大。并且,还给出了其在两地运行达到额定换热能力所应采取的各运行参数的区间。

Experimental Study of the Airside Performance for Interrupted Fin-and-tube Heat Exchanger with Hydrophilic Coating under Dehumidifying Conditions

The airside heat transfer and friction characteristics of seven interrupted fin-and-tube heat exchangers with hydrophilic coating under dehumidifying conditions are experimented.The effects of number of tube rows,fin pitch and inlet relative humidity on airside performance are analyzed.The test results show that the influence of fin pitch on the friction characteristic under dehumidifying conditions is similar to that under dry surface,and the friction factors decrease slightly with the increase of number of tube rows.The heat transfer performance decreases as fin pitch and number of tube rows increases.The heat transfer performance and the friction characteristic are independent of inlet relative humidity.Based on the test results,heat transfer and friction correlations in terms of the Colburn j factor and Fanning f factor,are proposed to describe the airside performance of the interrupted fin geometry with hydrophilic coating under dehumidifying conditions.The correlation of the Colburn j factor gives a mean deviation of 9.7%,while the correlation of the Fanning f factor shows a mean deviation of 7.3%.