2018 Volume 35 Issue 3 Pages 163-
World countries are planning to prohibit the use of current refrigerants and replace them with lower-global-warming potential (lower-GWP) refrigerants to reduce the emission of greenhouse gases from heat pumps. However, most of these refrigerants are relatively unstable and have weak flammability. Existing research does not conclusively prove their oxidative decomposition in the event of leakages, although it is suggested that humidity has an effect on their flammability limits. In this study, the lower limit temperature of oxidative decomposition was measured to assess the risk of using lower-GWP refrigerants that may possess weak flammability. The onset of decomposition and the generation of hydrogen fluoride of lower-GWP and conventional refrigerants were measured using a heating tube as a hot surface. Furthermore, the results verified the effects of temperature, humidity, refrigerant type, and hot wall materials.
