采用朗肯循环回收汽油机尾气余热的试验

Experiment on Rankine Cycle Waste Heat Recovery of Gasoline Engine

发动机尾气能量占燃料燃烧放热总量的35%,左右,采用朗肯循环系统回收发动机尾气能量是实现汽车发动机节能的有效途径.针对一台2.0,L汽油机,搭建用于回收尾气余热的朗肯循环试验系统,探究了汽油机不同负荷下朗肯循环系统的性能,并得到单阀膨胀机的示功图.结果表明:单阀膨胀机转速和输出功率随汽油机负荷的增加而增大.汽油机在4,000,r/min、90%,负荷工况下,膨胀机转速达到1,640,r/min,输出功率达到3.47,k W,相当于汽油机功率的5.8%,.当汽油机在转速为5,500,r/min、功率为76.6,k W的工况下,膨胀机的最高压力可以达到6.69,MPa,通过测试示功图计算得到的单阀膨胀机的指示功率可以达到5.06,k W.

Engine exhaust energy accounts for 35% of total fuel energy. If this energy is well recovered from Rankine cycle, it is an effective way to realize energy saving of automobile engine. The Rankine cycle test system for a 2.0 L gasoline engine was established to recover the exhaust energy. The performance of the Rankine cycle test system was studied and the indicated diagram of water-based single valve expander was obtained. Experiment shows that increas- ing gasoline engine load results in an increased speed and an increased output power of the expander. When gasoline engine runs under 90% load and 4 000 r/min, expander speed is 1 640 r/rain and output power reaches 3.47 kW, accounting for 5.8% of gasoline power. Maximum pressure in cylinder is 6.69 MPa and the indicated power of expander obtained by the indicator diagram is 5.06 kW when gasoline engine runs under 90% load and 76.6 kW power.