Regresar

Heating performance of vapor injection heat pump based on waste heat recovery

Abstract:

According to the heating requirements of electric vehicles (EVs) heat pumps in low ambient temperatures and extending the mileage of EVs, a waste heat recovery system in which the heat exchanger branch outside the vehicle and the branch of the waste heat exchanger are connected in parallel was developed and an experimental study on the heating performance was conducted. The experimental results show that, for the vapor injection heat pump system with parallel waste heat recovery branches, the pressure and mass flow of the vapor injection branch are significantly increased with the increase of the waste heat, while the mass flow of the main-branch is affected by the superheat at the outlet of the waste heat exchanger. The flow ratio of the out-door heat exchanger and the waste heat exchanger has a linear relationship, and the slope of the flow ratio is related to the outlet phase state of the waste heat exchanger. Under the relatively high ambient working conditions of 7℃, the increase of waste heat is beneficial to the increase of heating performance, but COP has no advantage; under the lower ambient working conditions of -20℃, the increase of waste heat increases the flow of injection mass large, but the suction mass flow is seriously attenuated, and the heating performance of the system is not significantly improved; under ambient working conditions of about -10—0℃, the heating performance and COP are greatly increased with the increase of waste heat, at -10℃, the heating performance with 1.8 kW waste heat increased by 11.6% compared to that with 0.9 kW waste heat, and the COP increased by 9.18%.