The thermal management system of electric vehicles is different from that of traditional passenger vehicles. For electric vehicles with a heat pump system and liquid cooling battery

the refrigerant charge is increased by 400–800 g compared with traditional air conditioning. If a combustible refrigerant is used

any leakage will spread to the passenger compartment

and the risk of combustion will increase. In this study

the concentration change process and maximum concentration of R1234yf refrigerant after evaporator damage and leakage with the air supply into the passenger compartment were dynamically monitored by numerical simulation. The results show that the refrigerant in the rear row accumulates more easily than that in the front row. After the refrigerant was completely leaked

the highest average R1234yf volume concentration at the four air outlets was 1.58%. The highest average R1234yf volume concentration at the breathing point of the four passengers was 0.99%. The highest average R1234yf volume concentration at the feet of the four passengers was 0.95%. The highest volume concentration in the passenger compartment was lower than the lower flammability limit of R1234yf. Compared with the test data of different vehicle models

it was found that different vehicle models had the greatest influence on the refrigerant volume concentration

which was 1.2% for different vehicle model.