CFD Analysis on the Diffusion and Accumulation Characteristics of Microleakage LPG in an Integrated Stove

Gas microleakage, which results in gas diffusion and accumulation in domestic gas appliances, is the leading cause of indoor gas explosion accidents. To research the diffusion and accumulation characteristics of microleakage gas in domestic gas appliances, this study took an integrated stove as the research object and analyzed the effects of different leakage rates and leakage locations on the diffusion and accumulation characteristics of microleakage liquefied petroleum gas (LPG) in its interior using the computational fluid dynamics (CFD) numerical simulation method. The results show that microleakage LPG is characterized by a downward diffusion flow driven by gravity and the concentration inside the integrated stove cavity generally increases with the increase of leakage time; however, the spatial distribution is extremely inhomogeneous. In addition, the volume of the dangerous area rapidly changes with the continuous accumulation of microleakage LPG, occupying more than 50% of the cavity volume. Microleakage LPG diffusion and accumulation process are highly similar under different leakage rates; on the contrary, the location of the leakage source is closely related to the diffusion and accumulation characteristics. The diffusion distribution and accumulation position of microleakage LPG at different leakage locations present obvious differences. Typically, there is a concentration difference of 0.1-0.2% between the top and the bottom when the leakage source is located above the gas stove baffle and a concentration difference of 1.0-1.3% between the top and the bottom when the leakage source is located below the gas stove baffle. In addition, the difference in the leakage location has a significant impact on the time the concentration of LPG reaches the critical concentration, which indicates that the combustion and explosion risk of different leakage locations are highly related to the leakage time. The research can provide certain technical support for microleakage gas explosion accident prevention.