新型文丘里分液头用于客车空调的实验研究

Experimental Study on Distribution Performance for Venturi Distributor on Bus Air-conditioning System

在压缩式制冷系统中具有优良分流性能的分液头可促进蒸发器获得最佳换热性能。本文提出一种新型的由文丘里喷射进口和分液头本体组合而成的文丘里型CX分液头,将其与目前应用的文丘里分液头的结构进行对比,并通过在客车空调系统中采用R410A工质进行对比实验,实验中保持系统其他部件不变及充注量相同,仅更换分液头,在制冷标准工况下进行系统性能对比。结果表明:采用CX分液头的制冷剂流动阻力减小了50%以上,蒸发器分路制冷剂出口温度均匀性显著改善,采用CX分液头系统明显优于原文丘里分液头系统,当系统的额定风量及压缩机频率恒定时,采用CX分液头的系统比原系统过冷度增加1~2℃,制冷量平均提高4%,COP平均提高2.6%,且电子膨胀阀的开度仅为原分液头系统的50%。

In compression refrigeration systems,an excellent distributor can provide an evaporator with the best heat transfer performance.This study develops a Venturi-type patent CX-distributor,which is composed of a Venturi injection inlet and distributor body.A comparative analysis is conducted between the CX-distributor and the Venturi distributor which is widely used at present.The contrast experiment is conducted in the R410A bus air-conditioning system,and the other parts except the distributor of the system are kept unchanged,including the same R410A charge quantity.Then,a comparative performance experiment of the system is performed under standard working conditions.The experimental results show that,compared with the original distributor,the refrigerant flow resistance of the CX-distributor is reduced by more than 50%,and the uniformity of the temperature distribution at the refrigerant outlet of the evaporator can be improved.Moreover,the refrigeration system performance using the CX-distributor is better than that of the original system.When the system is rated at a constant compressor air volume and frequency,the degree of subcooling of the CX-distributor system is 1-2℃higher than the original system,the average refrigerating capacity and coefficient of performance increase by an average of 4%and 2.6%,respectively,and the electronic expansion valve opening is only half of that of the original distributor.