徐鹏，韩雨，潘永传，王永健

潍柴动力股份有限公司，山东 潍坊 261061

摘要：为解决大气湿度较大时天然气发动机车辆在运行过程中出现的功率不足、放炮、爆震等问题，提出一种基于大气湿度的模糊控制方法，设计空气充量、废气再循环（exhaust gas recirculation,EGR）率以及点火角的修正模型，基于模糊控制方法，建立增压压力、EGR率及点火角的控制模型；使用MATLAB/Simulink软件模拟仿真大气湿度对天然气发动机性能的影响，并利用发动机台架试验进行验证。结果表明：仿真模型计算得到的发动机输出功率、失火率以及爆震强度随环境温度和大气湿度的变化趋势与台架试验结果相符，模型准确有效；模糊控制方法通过修正进气压力保证不同进气湿度和温度下干空气含量相同，通过适当修正EGR率可以调节失火率和爆震，通过调节点火角使气缸燃烧平稳、排放降低。该研究可以为大气相对湿度较大时天然气发动机性能改善提供参考。

关键词：天然气发动机；点火角；EGR率；增压压力；模糊控制

Abstract：In order to solve the problems of insufficient power, blasting, knocking, and other problems in operation of vehicles equipped with natural gas engines in high atmospheric humidity, a fuzzy control method based on atmospheric humidity is proposed, the correction models of air charge, exhaust gas recirculation (EGR) rate and ignition angle are designed. Based on fuzzy control method, the control models of boost pressure, EGR rate and ignition angle are established. Matlab/Simulink software is used to simulate the effect of atmospheric humidity on the performance of natural gas engine under different parameters, and engine bench test is used for verification. The results show that the engine output power, misfire rate and knock intensity calculated by the simulation model, with changes in ambient temperature and atmospheric humidity, are consistent with the results of the bench test, and the model is accurate and efficient. The fuzzy control method guarantees the same dry air content at different intake air humidity and temperature by correcting boost pressure, the misfire rate and knock can be adjusted by correcting the EGR rate appropriately, and the cylinder combustion and emissions can be improved by adjusting the ignition angle. The study can provide a reference for improving the performance of natural gas engines when atmospheric humidity is high.

Keywords:natural gas engine; ignition angle; EGR rate; boost pressure; fuzzy control