Leakage Safety Study On R290 Air Source Cold And Hot Water Heat Pump

Because of ozone depletion and global warming,searching for a new type of environmentally friendly refrigerant has become an urgent task.The propane has attracted much attention because of its good thermal performance and natural environmental protection.But the biggest problem for R290 is its flammability.This thesis is to study the safety of R290 air source cold and hot water heat pump.CFD simulation was used as a main method in the thesis.On the assumption that the diameter of the leak is 10 mm,the leakage amount is 1.3kg,the leakage time is 240 s and the whole process is leaking at a constant speed,several different simulations were carried out to study the influence factors of R290 leakage in the heat pump unit.The results showed that the location of heat pump had little effect.Increasing the number of circulating surfaces in the heat pump can speed up the diffusion of refrigerant.The air disturbance in the room can effectively solve the problem of refrigerant deposition and stratification.At the same time,two kinds of measures,opening small holes in the bottom of heat pump and ventilation,were studied and verified to be effective to reduce the risk of leakage.Experiment was also used in this study.In order to verify the feasibility of the simulation,a similar simulation was carried out according to the experiment.The experiment results showed that there was a high concentration of refrigerant accumulation near the floor of the room during the process of leakage and a short time after the leakage.Due to the differences of the initial conditions between experiment and simulation,the results were different in some respects.But all the differences can be explained.So the study method of CFD simulation is feasible.