494Q增压柴油机可靠性试验及改进措施分析

Reliability Experiment and Improvement Analysis on 494Q Turbocharge Diesel Engine

通过发动机试验台架,采用混合负荷方式对494Q增压柴油机进行了1000h的可靠性试验。分析了试验过程中遇到的润滑油油压突然降低的问题,并提出了改进措施。研究了改进后柴油机功率、扭矩与有效燃油消耗率随时间的变化关系,对比了试验前后柴油机的动力性及经济性指标。结果表明:增大柴油机润滑油泵齿轮宽度2mm能有效解决润滑油压力过低的问题。改进后的试验过程中,除燃油消耗率呈波动上升趋势外,功率、扭矩、排气温度均随时间波动下降。试验后标定工况点的有效燃油消耗率上升了2.3%,功率下降了3.4%。随柴油机转速的增加,进气流量逐渐增大,活塞漏气量先增大后减小,在转速为3000r/min时,活塞漏气量达到最大值70.2L/min。根据柴油机技术规范,以上试验结果表明改进措施切实可行。

According to the mix mode,the reliability experiment on494Q turbocharge diesel engine is done by using the engine test bench.The reason for the sudden drop in oil pressure is analyzed and the improvement is proposed.The power,torque and the effective fuel consumption rate are tested versus time on the improved engine.The dynamic and economic factors of the original engine and the engine after test are obtained by the comparative study.The results show that the sudden drop in oil pressure can be solved by increasing the gear width by 2mm in the oil pump.During the experiment,the fuel consumption rate increases with fluctuation versus time,while the power,torque and discharge temperature decrease with fluctuation versus time.In the rated case,the effective fuel consumption increases by 2.3% and the power decreases by 3.4%.The air inlet flow increases with the increase of engine speed.The air leak of piston increases and then decreases with the increase of engine speed.The maximum air leak by 70.2L/min appears in the case of 3000r/min.According to the technical specification for diesel engine,the results show that the improvement on the engine is practical.