热控阀（温控阀）工作失灵。热控阀安装于油冷却器前方，其作用是维持机头排气温度于压力露点以上。其工作原理是刚开机时由于油温较低，热控阀支路开启，主回路关闭，润滑油不经冷却器直接喷入机头；待温度升至40℃以上，热控阀逐渐关闭，油同时从冷却器和支路流过；升高到80℃以上，该阀全部关闭，润滑油则全部经冷却器再进入机头，以zui大程度对润滑油进行冷却。
The thermal control valve (temperature control valve) fails to work. The thermal control valve is installed in front of the oil cooler to maintain the exhaust temperature of the machine head above the pressure dew point. Its working principle is that when it is just started up, due to the low oil temperature, the branch of the thermal control valve is opened, the main circuit is closed, and the lubricating oil is directly injected into the machine head without passing through the cooler; When the temperature rises above 40 ℃, the thermal control valve is gradually closed, and the oil flows through the cooler and branch at the same time; When the temperature rises above 80 ℃, all the valves are closed, and all the lubricating oil enters the machine head through the cooler to Zui greatly cool the lubricating oil.
如果热控阀出现故障，则润滑油可能不经冷却器直接进入机头，从而油温无法下降，造成超温。其失灵的主要原因，一是阀芯上的大小两个热敏弹簧疲劳后弹性系数改变，不能随温度变化而正常动作；二是阀体磨损，阀芯卡死或动作不到位而无法正常关闭。可根据情况修理或更换。
If the thermal control valve fails, the lubricating oil may enter the machine head directly without passing through the cooler, so the oil temperature cannot drop, resulting in overtemperature. The main reasons for its failure are as follows: first, the elastic coefficient of the two thermal springs on the valve core changes after fatigue and cannot operate normally with the change of temperature; Second, the valve body is worn, the valve core is stuck or the action is not in place and cannot be closed normally. It can be repaired or replaced according to the situation.