A study of R290 gas concentration in air in case of leakages from a refrigerating circuit of a heat pump unit

The new rules regarding F-gas regulation are under discussion. Once they get approved, there would be a major shift in refrigeration and air conditioning industries towards using natural refrigerants that have very low Global Warming Potential (GWP) instead of using synthetic refrigerants with higher GWP. One of the biggest challenges in using natural refrigerants is that they are highly flammable and hence safety of the ambience where they are placed and of unit itself is a great issue in such units. One of the most promising natural refrigerants is propane (R290). The Scope of the Thesis is to numerically simulate the concentration of the leaked refrigerant in case of any leakage from the refrigerating circuit of an air-to-water heat pump unit working with Propane (R290) as refrigerant using an opensource simulation software OpenFOAM and then experimentally comparing the simulation results. One of the objectives of the thesis is to understand if R744 could be a reliable substitute of propane for the leakage experimental tests because CO2 is non-flammable and more convenient to be used. CFD simulations are used to compare the two-gas behavior in different test cases for both closed and open environment. Finally, the cabinet with forced ventilation of a real unit is simulated with the two gases. The experimental comparison is done using R744 gas leakage test in a real unit.