为了应对日益严格的碳排放法规，充分挖掘VVT和LPEGR技术对混合动力汽油机在节能方面的潜力，试验研究了VVT和LPEGR技术对混合动力发动机燃油消耗率的影响。结果表明：在不加入LPEGR时，燃油消耗率随进气VVT增大、排气VVT减小而降低，最佳进/排气VVT组合是50°/0°；不同VVT组合下加入LPEGR，燃油消耗率都呈下降趋势，但下降幅度不同，最大下降7.4%，且呈现出随进气VVT的增大，降幅和最佳EGR率逐渐减小的趋势；另外，最佳EGR率下的燃油消耗率则随VVT的减小而降低，最佳进/排气VVT组合是10°/0°，对应的最佳EGR率为23.2%，燃油消耗率为205.5 g/(kW·h)，说明VVT和LPEGR技术对改善燃油经济性具有较大潜力且LPEGR技术的潜力更大。
In order to meet the increasingly stringent carbon regulations and fully tap the potential of VVT and low-pressure EGR technology in energy saving for hybrid gasoline engine, the effects of VVT and low-pressure EGR technologies on fuel economy of hybrid engine were experimentally investigated. The results show that the specific fuel consumption of hybrid engine without lowpressure EGR decreases with the increase of intake VVT and the decrease of exhaust VVT and the optimal intake and exhaust VVT combination is 50° and 0°. The specific fuel consumptions all decline after introducing lowpressure EGR under different VVT combinations, but the decreases are different with the maximum decrease of 7.4%. And the decrease of specific fuel consumption and the optimal EGR rate gradually decrease with the increase of intake VVT. In addition, the specific fuel consumption decreases with the decrease of VVT at the optimal EGR rate. The optimal combination of inlet and exhaust VVT is 10° and 0°, the optimal EGR rate is 23.2%, and the corresponding specific fuel consumption is 205.5 g/(kW·h). According to the above analysis, the VVT and low-pressure EGR technologies have a great potential for improving fuel economy and it is especially true for low-pressure EGR technology.
