用灰色决策法评估不同甲醇替代率对船用双燃料柴油机性能的影响OA

To address the growing demand for emission reduction and fuel diversification in the shipping industry while considering the low-cost retrofit of existing vessels,a marine four-stroke methanol/diesel dual-fu-el engine test platform was established in this study.Methanol was introduced through intake manifold injec-tion.A multi-parameter evaluation system for marine dual-fuel diesel engines was developed based on experi-mental data.Grey decision-making theory was applied to comprehensively assess the power performance,fuel e-conomy,and emission characteristics of the engine under different methanol substitution rates at 75%load.The results indicate that,with increasing methanol substitution rate,cylinder pressure and combustion intensity in-creased,in-cylinder temperature rose,brake specific fuel comsumption decreased,and both brake thermal effi-ciency and indicated power improved.Meanwhile,NOx emissions were significantly reduced,soot emissions de-creased slightly,whereas CO emissions increased.The grey decision-making results identified the optimal meth-anol substitution rate as 40%.At this substitution rate,compared with the original diesel-fueled engine,fuel consumption decreased by 5.9%,cylinder pressure increased by 0.39 MPa,and NOx and soot emissions de-creased by 28%and 35%,respectively,while CO emissions increased by 74%.