某柴油机过热故障分析

Trouble Analysis of Overheat for Diesel Engine

某水冷柴油机在进行耐久性考核试验过程中,出现曲轴箱废气压力突然升高,排温升高的故障现象。经拆检分析确定了该故障产生的原因是整机过热造成的。为了分析整机过热原因,建立了相应的故障树,通过逐条排查分析,找出了故障发生的根本原因是:由于冷却系统膨胀水箱蒸汽阀密封不严,造成闭式冷却循环系统失效,冷却液汽化,循环系统产生气阻,并最终导致水泵供水量不足,引发柴油机过热故障。故障排除后,整机重新进入考核试验,并顺利通过了耐久性考核,验证了故障定位合理性和所采取措施的可行性。

Trouble of crankcase waste gas pressure and exhaust temperature rising occurred during water - cooled diesel engine durability test. It＇s found that the trouble is caused by engine overheat by dismantling and examining analysis. The essential reason of engine overheat can be found by establishing corresponding trouble trees and examining analysis one by one. The reason leading to the trouble is that： Sealing insufficiently for expansion water tank steam valve of cooling system leads to cooling water boil away and brings vapor lock for circle system, and makes for water supplying insufficiently of water pump finally. Diesel engine was retested on durability and the test was accomplished successfully when the trouble was eliminated. That success verified rationality of trouble localizing and feasibility of technical method.