变温工况下可燃制冷剂的爆炸极限

Explosion Limits of Flammable Refrigerants Under Condition of Variable Temperature

鉴于当前紧迫的HCFCs淘汰形势,很多学者针对替代潜力较大的HFC161和HC1150的热力性质、循环性能以及常温下可燃性等进行了研究,然而针对变温工况下上述可燃制冷剂爆炸极限影响规律的研究却极为少见.为此,本课题组建立了一套由上位机自动控制的可燃气体爆炸极限测试系统,并对HFC161和HC1150在-3～55,℃范围内的爆炸极限进行了试验研究.结果表明:在一定的温度范围内,温度升高会使不可燃的混合气体出现热激化现象,而成为可燃可爆状态.当环境温度由-3,℃升高到55,℃时,HFC161和HC1150的爆炸极限范围分别增加了1.42%、4.59%.低温对制冷剂爆炸极限有较明显的抑制作用;2种工质的燃爆特性的温度敏感区大约位于10～40,℃区间,当温度高于40,℃或低于10,℃时,温度对制冷剂可燃上、下限的影响均减弱.试验结果和变化规律为可燃制冷剂在变温工况下的安全应用奠定了基础.

Because of the urgent situation of HCFCs elimination, many scholars have studied the thermodynamic properties, cycle performances and flammability at room temperature of HFC161 and HC 1150 which are considered as great potential alternative refrigerants. However, few literatures have involved the effect of variable temperature on explosion limits of refrigerants mentioned above. For this reason, an experimental apparatus for testing the explo- sion limits of flammable refrigerants was established which was automatically controlled by computer. A series of ex- periments were carried out to test the explosion limits of HFC 161 and HC 1150 in the temperature range of-3 --55 ℃. Results show that non-combustible gas mixtures can be thermally excited with the increase of temperature, and then come into a flammable and explosive state within a certain temperature range. When the ambient temperature in- creases from -3 ℃ to 55 ℃, the explosion limits of HFC161 and HCll50 are increased by 1.42% and 4.59%, respectively. Low temperature can have an obvious effect on the inhibition of explosion limits. For the explosion char- acteristics of refrigerants focused in this paper, the temperature sensitive area is located in the range of 10--40 ℃ approximately. When the temperature is above 40 ℃ or below 10 ℃, its influence on both upper and lower explosion limits weakens. Research achievements supply foundational parameters for safe application of flammable refrigerants under variable temperature conditions.