【作者】 王晓玲；

【导师】 周亚素；

【作者基本信息】 东华大学 ， 供热、供燃气、通风及空调工程， 2018， 硕士

【摘要】 蒸发冷却技术从很早就开始为人类创造比较舒适的生活环境做出贡献,它是通过降低干球温度来达到冷却的一种技术。近年来,蒸发冷却技术在国内外的应用已经非常广泛,各种单独的或者组合的直接蒸发冷却空调在我国已经大量地生产,而直接蒸发冷却式空调对我国关于低耗能制冷技术的应用与推广起到了非常大的作用。但是,直接蒸发冷却空调的温降有限,由此出现了间接蒸发冷却空调技术,间接蒸发冷却是将直接蒸发冷却得到的空气或水用于冷却被处理的空气,该过程是通过非直接接触的换热器来进行的。间接蒸发冷却的空气处理过程相比直接蒸发冷却多了一段等湿降温过程,因此可以得到更低温度的送风,但是间接蒸发冷却空调技术容易出现管道堵塞、生锈,使维护成本增大。因此本课题提出一种带盘管直接蒸发式冷却器是一种新的冷却器——在直接蒸发冷却器前加置一个翅片盘管段,它是将直接蒸发冷却用水在翅片盘管内循环来对被冷却的空气进行预冷作用,预冷后的空气再经过直接蒸发冷却可以被冷却到更低的温度。在通过理论分析与实验研究,本文研究了该带盘管直接蒸发式冷却器的进口空气迎面风速和盘管流量占比对其冷却性能的影响。实验结果显示,当进口空气迎面风速为2.5m/s、盘管流量占比为40%时,空气出口干球温度最低,从38℃降低到22.4℃,温差达到15.6℃,此时的冷却效率最高为104%。当考虑到压力损失随空气迎面风速的增加呈正比例地增长的实验结果,本文提出阻力系数ε来描述该带盘管直接蒸发式冷却器的经济性能,最终确定最节能经济且冷却效果较高的工况为空气迎面风速1.0m/s,盘管流量占比为40%,此时冷却效率为98.7%。在带盘管直接蒸发式冷却器的冷却性能研究中,分别改变空气迎面风速和盘管流量占比,发现:(1)在不同的空气迎面风速下,各个冷却性能参数的变化随着盘管流量占比的变化呈现出相同的规律,且均在盘管流量占比为40%时冷却效率最大、阻力系数最小;(2)而在不同的盘管流量占比下,该带盘管直接蒸发式冷却器的冷却性能参数随着空气迎面风速的变化呈现不同的变化规律,当空气迎面风速为2.5m/s时,该带盘管直接蒸发式冷却器的冷却效率最大;当空气迎面风速为1.0m/s时,该带盘管直接蒸发式冷却器的阻力系数最小即经济性能最好。所以,总的来说,带盘管直接蒸发式冷却器的盘管流量占比和空气迎面风速这两个运行工况对冷却器的冷却性能有着重要的影响。更多还原

【Abstract】 Evaporative cooling technology,which has long since begun to create a more comfortable living environment for humans,is a technique for cooling the dry bulb to cool.In recent years,the application of evaporative cooling technology at home and abroad have very extensive,various individual or combination of direct evaporative cooling air conditioning in our country has a large number of production,and direct evaporative cooling air conditioning to our country about the application of low energy refrigeration technology and promotion has played a very big effect.However,direct evaporative cooling air conditioning temperature drop is limited,thus the indirect evaporative cooling air conditioning technology,indirect evaporative cooling is will be of direct evaporative cooling air or water used for air cooling is processed,the process is through the direct contact heat exchanger.Indirect evaporative cooling air handling process compared with the direct evaporative cooling is more a wet cooling process,so you can get more low temperature air supply,but indirect evaporative cooling air conditioning technology prone to blockage,rust,increased maintenance costs.So this topic with a coil is put forward the direct evaporative cooler is a new kind of cooler,in front of the direct evaporative cooler add buy a fin plate section,it is the direct evaporative cooling water circulation in the fin plate tube to the cooled air precooling,precooling air again after a direct evaporative cooling can be cooled to a lower temperature.Through theoretical analysis and experimental study,this paper studies the influence of the inlet air head wind speed and coil flow ratio of the direct evaporative cooler of the coil pipe on the cooling performance of the pipe.The experimental result shows,when inlet air head on wind speed 2.5 m/s,coil tube flow rate 40%,air outlet dry bulb temperature is the lowest,reduced from 38 ℃ to 22.4 ℃,the temperature is 15.6 ℃,the cooling efficiency as high as 104%.When considering the power loss with the increase of the air on wind speed was positively proportional to the growth of the experimental results,this article with coil epsilon resistance coefficient to describe the proposed economic performance of the direct evaporative cooler,ultimately determine the most energy-efficient economy and high operating mode of air cooling effect on the wind speed 1.0 m/s,coil tube flow rate 40%,the cooling efficiency of 98.7%.In the study of cooling performance of the direct evaporative cooler of the coil pipe,the ratio of air head wind speed and coil flow rate was changed respectively.Found that:(1)under the different air head on wind speed,the cooling performance parameters change with the change of the coil pipe flow of show the same rule,and in the coil pipe flow 40% maximum cooling efficiency and minimum resistance coefficient;(2)and under the different coil pipe flow of the belt of direct evaporative cooler coil head on wind speed changes with the air cooling performance parameters,the change rule of different when air head on wind speed 2.5 m/s,the tape coil direct evaporative cooler cooling efficiency of the biggest;When the wind speed of the air is 1.0 m/s,the resistance coefficient of the direct evaporative cooler of the coil is the least of the economic performance.Therefore,in general,the cooling performance of the coolers has an important impact on the cooling performance of the cooling device of the direct evaporative cooler.更多还原