基于图像处理法的间接蒸发冷却器喷淋布水效果的试验研究

Experimental study of spray water distribution effect of indirect evaporative cooler based on image processing

针对如何提高间接蒸发冷却器的润湿特性,以改善实际工程应用中的布水均匀性的问题,搭建了芯体布水实验台,采用水基荧光显示和数字图像处理法,重点研究了喷淋时间(5~180 s)、喷淋流量(2~6 L/min)以及喷嘴高度(50~250 mm)对芯体中3个典型位置的金属铝箔板表面布水效果和润湿率的影响。结果表明:随着喷淋时间的增加,板面润湿率增加,但一定时间后,进入动态稳定期。在喷射角为58°、喷淋流量为5 L/min的工况下,芯体边缘处需喷淋60 s后达到布水稳定。喷嘴高度的变化对正下方和边缘处的板布水影响较明显,推荐的喷淋高度为150~200 mm。研究结果对间接蒸发冷却器的布水参数设计具有指导意义。

For the problem of how to improve the wetting characteristics of indirect evaporative cooler(IEC)to improve water distribution uniformity in engineering applications,a test bench for core water distribution was built,and water-based fluorescence display and digital image processing methods were used to investigate the influences of spraying time(5~180 s),spray water flow rate(2~6 L/min)and nozzle height(50~250 mm)on the water distribution effect and wettability of aluminum foil plates at the three typical positions in the core body.The results show that with the increase of spraying time,the wetting ratio of the plate surface increases,but it reaches a dynamic stable status after a certain time.Under the injection angle of 58°and flow rate of 5 L/min,water distribution stability is achieved on the edge of the core after 60 s of spraying.The change of nozzle height has an obvious effect on the water distribution at the bottom and edge of the plate,and the recommended spray height is 150~200 mm.The results can provide guidelines for the design of IEC water distribution parameters.