Development of evaluation method of self-decomposition reactions of next-generation refrigerants. 1st report: development of ignition method.

HydroFluoroOlefin (HFO) is gaining attention as a next-generation refrigerant with low environmental impact. However, HFO refrigerants pose safety concerns due to the self-decomposition reaction, which is linked to their molecular stability. A rapid increase in temperature and pressure may occur if self-decomposition propagates in the refrigeration cycle. Evaluating refrigerant stability is crucial for practical applications, yet no established methods exist. Therefore, the development of reliable standards is needed. In this report, a fusing wire and discharge method was developed as an ignition source, which is a critical issue for standardization. In this method, a thin metal wire (fusing wire) is placed between electrodes. Current is passed through it, and after the wire is fused, an arc discharge occurs between the electrodes. The characteristics of this method and the energy imparted to the refrigerant were investigated under various gas pressures and electrode distances.