喷射模式对高压缩比甲醇发动机爆震特性影响的试验研究

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关键词：甲醇；高压缩比；爆震特性；爆震抑制；喷射策略

中图分类号：TK431文献标志码：A

DOI：10.7652/xjtuxb202507011 文章编号：0253-987X（2025）07-0108-10

Experimental Study of the Effect of Injection Mode on Knock Characteristics of High Compression Ratio Methanol Engines

YU Lixin，YIN Xiaojun，WANG Xibin，DUAN Hao，HU Erjiang，ZENG Ke （School of Energy and Power Engineering，Xi'an Jiaotong University，Xi’an 71oo49，China）

Abstract： To investigate the knock suppression methods for high compression ratio methanol engines， an experimental study is conducted on a single-cylinder naturally aspirated spark-ignition methanol engine with a compression ratio of 15：1 ，focusing on the impact of injection modes on knock characteristics under stoichiometric mixed gas conditions.First，the influence of load， ignition timing，and air-fuel ratio on knock characteristics is explored under the intake port injection mode. Second，the effect of injection timing on knock characteristics is examined under the direct injection mode. Finally，the suppression efect of multiple injection strategies on knock is analyzed under wide-open throttle conditions. The results indicate that in the intake port injection mode， the methanol engine experiences knock combustion at medium to high loads，with a strong knock phenomenon characterized by low frequency and high intensity，reaching a maximum knock intensity of 8.42MPa at an indicated mean effective pressure （ϕi） of 0.7MPa . In contrast，under the direct injection mode，the knock phenomenon is significantly suppressed，with the maximum knock intensity dropping to 0.43MPa when ϕi is 0.91MPa .A reasonable two-injection strategy further reduces knock intensity compared to a single injection strategy while maintaining a highρi . This study confirms the effectiveness of combining direct injection with a two-injection strategy in suppressing knock phenomena in high compression ratio methanol engines，providing theoretical basis and data support for the development and application of methanol engines.

Keywords： methanol；high compression ratio；knock characteristics；knock suppression； injection strategy

化石燃料的持续消耗引发了愈发凸显的环境污染和全球变暖问题，威胁着人们赖以生存的环境，同时制约了经济社会的发展。（剩余14265字）