车用CO2热泵系统余热回收对制热性能提升机制的试验研究OA

To address the efficiency degradation of CO2 heat pump(HP)systems caused by insufficient air-side heat absorption capacity at low temperatures,this study proposes a CO2 HP system incorporating waste heat recovery.Bench tests,conducted under 100%fresh air conditions with constant supply air temperature control,compared the heating efficiencies among the waste heat-only,dual heat source,and air source-only modes.The impact of heat source grade matching on system performance was also revealed.By elevating the evaporation pressure,this approach effectively reduces the compression ratio,thereby enhancing the system's heating performance.The results indicate that the refrigerant temperature at the outlet of the inner gas cooler exhibits a negative correlation with the COP.A comparative analysis reveals that at ambient temperatures of-10℃and 0℃,the waste heat-only mode increases the COP by 13.5%and 21.8%,respectively,compared to the air source-only mode,and extends the average driving range by 6.72%.The energy efficiency of the dual heat source mode is better than that of the air source-only mode,effectively widening the low-temperature operating range.Furthermore,the lower the ambient temperature,the more significant the energy efficiency improvement.Under the-20℃100%fresh air condition,the heating capacity and COP increase by 4.9%and 14.2%,respectively,compared with the air source-only mode.