电动增压器对柴油发动机低速稳态性能的影响

The Influence of Electric Supercharger on Steady State Performance of Engine at Low Speed

相比于涡轮增压,电动复合增压技术可以提高发动机进气流量和进气响应。通过研究电动增压器转速对发动机扭矩、空燃比和经济性的影响,得出外特性工况下电动增压器的最佳工作点。基于废气涡轮增压器功率、进气功率和燃烧效率,对电动复合增压发动机进行性能仿真,并将电动复合增压发动机与原机进行性能对比。结果表明:电动复合增压系统可以有效提升发动机低速大扭矩区域的工作性能,发动机低速大扭矩区域增加约18%,油耗在220 g/(kW·h)以下区域增加约16.7%;在指示功率增量中,动力循环功增量远大于增压功率提升;增压功率增量主要由废气涡轮增压器的增压功率提升组成;废气涡轮焓降功率提升是废气涡轮增压功率提升的主因。

Compared with turbocharging,the hybrid electric supercharging technology can improve the air intake volume and responsiveness of engine.The influence of rotating speed of electric supercharger on engine torque,air-fuel ratio and economy is studied to obtain the best working point of electric supercharger.The performance of electric hybrid supercharged engine is simulated based on the power,intake power and combustion effeciency of exhaust lurbocharger.The performance of hybrid electric turbocharged engine was compared with that of the original engine.The results show that the hybrid electric turbocharging system can effectively improve the performance of engine in the low rotating speed and high torque area,the low rotaing speed and high torque area of engine is increased by about 18%,and the fuel consumption is increased by about 16.7%in the area below 220 g/kWh;in the indicated power increment,the power increment of power cycle is far greater than that of the supercharging power;and the supercharging power increment is mainly increased by the supercharging power of the exhaust gas turbocharger.The main reason for the increase in turbocharging power is the enthalpy drop of exhaust gas turbine.