基于等效等熵指数的燃烧始点实时反馈与控制

Real-time start of combustion feedback and control based on equivalent isentropic index

针对压燃发动机燃烧相位的循环波动问题,开发了新一代集成缸压采集、燃烧状态反馈、燃烧控制和发动机控制功能的控制平台;提出了一种基于等效等熵指数一阶导数的燃烧始点检测算法;设计了循环内燃烧始点控制算法和循环间的燃烧始点控制算法。实验结果表明,基于等效等熵指数一阶导数的燃烧始点检测算法,能够实时检测燃烧始点;根据燃烧放热率规律提出的循环间燃烧始点控制算法,能够控制燃烧始点到目标值,减小燃烧始点相位的循环波动;提出的循环内燃烧始点控制算法,能够保持不同EGR率下主喷燃烧始点相位的一致。

In order to reduce cycle-to-cycle combustion phase fluctuations,a new control platform with functions of cylinder pressure acquisition,combustion states feedback,combustion control and engine control is developed. A novel Start of Combustion(SOC)detection algorithm based on the first derivative of the equivalent isentropic index is presented. Both next-cycle and in-cycle SOC control strategies are introduced. Experimental results demonstrate that the detection method is able to detect the real-time SOCs. The next-cycle control strategy according to the profiles of the heat release rate can control the SOC phase to its target and reduce cycle-to-cycle SOC phase fluctuations. The in-cycle control strategy can keep the consistency of the SOC phase of the main injection under different exhaust gas recirculation rates.