Research On LNG Engine Gas Injection And Ignition System Control Method

In recent years, haze constantly harass the world’s major cities and make an unprecedented threat to people’s life and health. However, automobile exhaust emission is one of the causes of haze. So countries have to find clean vehicles energy. Natural gas become the best choice for alternative energy sources by its low emissions and abundant. The LNG(liquefied natural gas) becomes the focus of attention for its storage with high efficiency, long mileage, the low pressure fuel container, recyclable energy vaporization, the use of gas by the impact of small outlets etc. However, natural gas engine power is low, has been much criticized. Therefore, enhancing the power and reducing gas consumption of LNG engine has been a goal of LNG vehicles research.In this paper, a certain type of LNG Weichai WP12 engine was based on the original engine. It doesn’t change the hardware configuration, just research on the electronic control system of LNG engine jet and ignition control system. The LNG engine is modeled by MATLAB/Simulink software and optimized by BP neural network to improve the performance of the LNG engine.According to the operation characteristics of LNG engine, the BP neural network adaptive PID control strategy is proposed for the gas injection system. Furthermore, the optimization of gas injection system is completed by using BP neural network. Using MC9S12XS128 MAL as the control core, the control circuit design of gas injection control system is carried out, which includes power module, signal acquisition circuit, ignition drive circuit etc.The ignition control strategy of LNG engine is studied. The BP neural network is designed according to the ignition control strategy of LNG engine. The ignition advance angle of the LNG engine is calibrated based on the mean value model, and the initial MAP diagram is obtained. On this basis, the ignition control system is completed by using the BP neural network.Since LNG modeling engine, gas system optimization and development, high-energy ignition system optimization is established by MATLAB/Simulink mean models, ignoring the engine transient changes, just use an average value of each parameter. In order to verify the reliability of the optimization, AMESim is used to model and the optimized parameter is input model to verify. The data are compared with the measured data. The optimized development of LNG engine electronic control system is realized, which provides a feasible research method for the engineering application.