Numerical Analysis of Flammability Risks from Propane Leaks Inside HVAC Unit

The need to find an alternative refrigerant with a low level of Global Warm-ing Potential (GWP) has become a critical priority in many HVAC and refrigeration applications. Therefore, there is growing interest toward the use of hydrocarbon re-frigerants, such as propane (R290), which has a significantly low GWP (=3) and no Ozone Depletion Potential. However, under European F-gas regulations, propane is classified as a flammable refrigerant, limiting its use due to the safety concerns. De-spite this, propane remains a highly competitive option for various commercial and industrial applications due to its excellent thermophysical properties and thermal ef-ficiency. This study presents a 2D numerical investigation of different propane gas leakage scenarios inside a gas-to-gas commercial HP unit. The numerical simulations were conducted using Computational Fluid Dynamics (CFD) software ANSYS-FLUENT. Different factors such as different hole leakage position and presence of obstacles were considered. Initial results are reported in terms of propane leak con-centration, identifying potential flammability risk zones within the enclosed space. The findings of this study present the most critical scenarios to be considered for the safe use of this flammable refrigerant.