针对M100甲醇发动机低温环境下难以形成足够浓度可燃混合气而导致的起动困难问题，从改善M100甲醇燃料雾化及提升混合气温度两方面开展了研究。采用空气辅助喷射器降低甲醇燃料喷雾粒径，促进其形成可燃混合气；采用进气加热方式将起动阶段进入气缸的甲醇混合气加热，提高甲醇蒸发速度，加速低温下甲醇混合气浓度达到着火界限。试验结果表明：空气辅助喷射器对改善M100甲醇燃料发动机起动性能有利，比普通甲醇喷射器的极限起动温度降低10 ℃；进气加热可加速甲醇混合气形成；两种方案组合可实现环境温度5 ℃下缸内着火。

Aiming at the starting difficulty of M100 methanol engine due to the difficulty of forming a sufficiently concentrated combustible mixture at low temperature, research was carried out to improve the atomization of M100 methanol fuel and to increase the temperature of mixture. The airassisted injector was used to reduce the spray particle size of methanol fuel to promote the formation of the combustible mixture and the intake heating method was used to heat the methanol mixture entering the cylinder during the starting phase to increase the evaporation rate of methanol and accelerate the concentration of methanol mixture to reach the ignition limit at low temperature. The test results show that the airassisted injector is beneficial to improve the starting performance of M100 methanol fuel engine, and the limit starting temperature is 10 ℃ lower than that of ordinary methanol injector. Intake heating can accelerate the formation of methanol mixture. The combination of the two schemes can realize the incylinder ignition at the ambient temperature of 5 ℃.