Leakage Simulation of Higher Flammable Refrigerant from Reach-in Refrigerated Display Cabinets

Abstract

In this study, a computational fluid dynamics analysis was conducted on the behavior of highly flammable refrigerant R 290, which is considered to be a next-generation refrigerant candidate for commercial refrigerating appliances when it leaks indoors. To verify the validity of the analysis model and calculation method, we conducted a leakage experiment from the reach-in refrigerated display cabinet and compared it with the calculation results. In the experiment, we used R 744, whose physical properties are close to those of R 290. This study aims to evaluate the agitation effect of a condenser fan to ensure safety when refrigerant leaks from commercial refrigerating appliances. The diffusion of flammable gas after a refrigerant leak was simulated using the direction of the airflow from the condenser fan and the wind speed as parameters. We also considered the effect of the room area where the cabinet is installed and the refrigerant charge. As a result, it was found that the generation of flammable gas can be sufficiently suppressed by properly operating the condenser fan.