可燃制冷剂R32室内空调器泄漏扩散特性的实验研究

Experimental Study on the Leakage and Diffusion Performance of Flammable Refrigerant R32 in Split-type Air-conditioner

制冷剂R32具有良好的环保特性和热工性能,但其可燃性限制了它的应用推广,因此需要对R32的安全性进行分析。实验研究了分体壁挂式空调用制冷剂R32在空调运行时,蒸发器不同泄漏位置和不同泄漏速度对室内R32浓度分布的影响,得出R32在空调运行时的泄漏扩散特性。研究表明:可燃性制冷剂R32在室内机蒸发器处发生泄漏时,泄漏过程可分为快速泄漏阶段和低速泄漏阶段;蒸发器出口泄漏比蒸发器入口泄漏危险性高;仅在蒸发器出口大流量泄漏时,室内机附近区域R32浓度最大值为16.79%,超过可燃下限(14.4%)16.6%。可燃浓度持续了22 s,存在着火的可能性,但概率较低;排风作用对各测点的浓度衰减影响强烈,可有效降低室内R32的浓度。

R32 is a potential alternative refrigerant for its environmental protection capability and thermal performance. But the slight flammability limits its application. Therefore,safety analysis is needed. This paper studied the influence of different leakage locations and rates on the indoor R32 distribution with air conditioner operating,and obtained the R32 leakage and diffusion characteristics. It showed that the leakage at the evaporator of indoor unit can be divided into two processes,fast leakage stage and slow. Outlet leakage of the evaporator is more dangerous than the inlet. And only large leakage flow in evaporator outlet can cause high R32 concentration near the indoor unit,reaching 16. 79%,which exceeds the lower flammable limit（ 14. 4%） 16. 6%. If flammable concentration exists for 22 s,the fire probability exists but it＇s low. Air exhausting can decrease the concentration of indoor R32 effectively.