多缸柴油机燃烧过程缸间差异统计分析

分析了多缸柴油机产生缸间差异的原因,提出了采用统计学STUDENT试验方法判别多缸发动机缸间差异产生的原因。实测了一台四缸直喷式柴油机气缸压力,分析其平均指示压力、燃烧始点、最大气缸压力和最大压力升高率及对应相位等参数的波动与缸间差异,并对平均指示压力缸间差异进行统计分析。结果表明,该柴油机燃烧过程缸间差异较大,其产生的原因并非偶然,而是存在技术原因,需要进行改进。

Analysis of Cylinder to Cylinder Variation of Combustion Process of DI Diesel Engine by Statistics Method

The cylinder to cylinder variation of multi cylinder diesel engine has great influence on its power, fuel consumption and emissions, etc. The causes of cylinder to cylinder combustion variation were analyzed in a multi cylinder diesel engine, and the STUDENT experimental statistics method has been used to judge whether the combustion variation was incidental or there was technical problem in the diesel engine. The cylinder pressures of a four cylinder DI diesel engine were measured. The cycle to cycle and cylinder to cylinder variations of indicated mean effective pressure, ignition time, peak cylinder pressure, maximum raise of cylinder pressure and their corresponding angle were analyzed. The STUDENT experimental statistics method was used to analyze the cylinder to cylinder variation of indicated mean effective pressure. The results showed that the cylinder to cylinder combustion variation of the engine is large, and the reason is not incidental, there are some technical problems which need to be improved.