天然气发动机高温停机保护策略测试

Test on protection strategy for high temperature shutdown of a natural gas engine

为解决常年高温地区易出现的发动机高温故障,分析发动机高温原因及危害;通过逻辑分析,制定发动机保护机制,提出当发动机过热时将转矩强制置0、设置转速限值触发燃料供给限制、强制锁定节气门开度为初始状态3种保护策略并进行测试;选择最优控制策略增加延迟停机动作进行实车试验验证。结果表明:发动机出现高温故障时,3种控制策略中,设置转速限值触发燃料供给的保护策略效果最好;在此策略基础上延迟停机时间为150 s,停机后冷却水的最高温度为98.5℃,满足使用需求。

In order to solve the high temperature failure of the engine that occurs in high temperature areas,the cause and harm of the high temperature of the engine is investigated.By logical analysis,the engine protection mechanism is formulated,and the torque is limited when the engine is overheated.Lock the throttle openness in the initial state of 3 protection strategies and test it,select the best of the three control strategies to increase the delayed parking action for real car test verification.The results show that the protection strategy of setting up speed limit triggering fuel supply is the best effect among the 3 control strategies.On the basis of this strategy,when the shutdown time is delayed by 150 s,the maximum temperature of the cooling water after shutdown is 98.5℃,which meets the needs of use.