为提高柴油机的可靠性和标定工作效率,以某柴油机为试验对象,基于正交试验设计方法,研究最低油耗工况下喷油压力、喷油时刻、废气再循环(exhaust gas recirculation,EGR)阀开度3个因素对发动机爆发压力的影响,并通过计算极差与方差分析影响因素的敏感性.结果表明:喷油压力由120 MPa增大到140 MPa,爆发压力增大1.04 MPa;提前角由上止点前曲轴转角8°增加到10°,爆发压力增大1.68 MPa;EGR阀开度由50%降低到30%,爆发压力增大0.55 MPa.3个因素对爆发压力的影响敏感性顺序为:喷油时刻、喷油压力、EGR阀开度.
Analysis of the sensitivity of factors affecting the peak pressure of a diesel engine based on orthogonal experiment design method
In order to improve the reliability and calibration efficiency of diesel engines,a certain diesel engine is taken as the experimental object,based on the orthogonal test design method,the effects of injection pressure,injection timing,and exhaust gas recirculation(EGR)valve opening on engine peak pressure under the lowest fuel consumption condition are studied,and the sensitivity of the influencing factors is calculated by range and variance analysis.The results showes that as the injection pressure increases from 120 MPa to 140 MPa,the peak pressure increases by 1.04 MPa.The advance angle increases from 8° to 10° before the top dead center,and the explosion pressure increases by 1.68 MPa.The opening of the EGR valve decreases from 50%to 30%,and the peak pressure increases by 0.55 MPa.The sensitivity order of the three factors affecting peak pressure is:injection timing,injection pressure,EGR valve opening.
orthogonal test design methodinjection pressureinjection timeEGR valve openingpeak pressurefactor sensitivity