用VVT法控制涡轮增压汽油机负荷和增压压力的研究

Controlling the Load and Boost Pressure of Turbocharged SI Engines by Means of VVT

本文在分析涡轮增压汽油机负荷和增压压力的常规调节法的基础上提出了一种新的调节方法,即VVT法。该方法是通过控制进气门的关闭定时来控制这类发动机的负荷和增压压力,从而抛弃了传统的节气门和废气放气阀等系统。研究结果衣明,采用VVT法的最大优点是能有效地降低这类发动机的爆震倾向和明显地改善其换气功。本研究采用了西柏林工业大学内燃机研究所开发的模拟涡轮增压汽油机工作过程的计算程序。该程序的模拟精度在文中用实验结果进行了验证。

A new control concept is developed in this paper for controlling the load and boost pressure of turbocharged SI engines on the basis of analyzing the conventional one. In the so-called VVT (Variable Valve Timing) system the load and boost pressure of those engines are controlled by means of controlling the intake-valve closing time without the conventional throttle and waste gate system. This study shows that the main advantages of the VVT control concept are the effective reduction of the tendency to knock and the substantial improvement of the pumping loss. Computer programs for the cycle simulation of the turbocharged SI engines, which were developed by the Institute of Internal Combustion Engines, Technical University Berlin/Germany, are used for this analysis. The comparisons between the predicted and measured results are conducted in this paper to give the confidence on the simulation programs.