CAJ | 학술논문

将1台柴油机改造为高压缩比（17．5）、带有节气门、进气道喷射和点燃式的甲醇发动机，研究了点火正时对1400 r/min转速下燃烧和排放性能的影响。研究结果表明：在全负荷工况，点火正时为18°BTDC ，15°BTDC和12°BTDC时甲醇发动机能够平稳运转；受发动机爆震限制，随着发动机负荷的增加，最大点火正时推迟；甲醇发动机负荷增加，点火滞燃期有所缩短，缸内压力峰值和放热率峰值显著增加；随着点火提前角的增加，燃烧提前，缸内压力和放热率峰值增加，燃烧持续期缩短。优化点火正时有利于获得良好的经济性和排放性折中效果，在中低负荷时尤为明显。
장1태시유궤개조위고압축비（17．5）、대유절기문、진기도분사화점연식적갑순발동궤，연구료점화정시대1400 r/min전속하연소화배방성능적영향。연구결과표명：재전부하공황，점화정시위18°BTDC ，15°BTDC화12°BTDC시갑순발동궤능구평은운전；수발동궤폭진한제，수착발동궤부하적증가，최대점화정시추지；갑순발동궤부하증가，점화체연기유소축단，항내압력봉치화방열솔봉치현저증가；수착점화제전각적증가，연소제전，항내압력화방열솔봉치증가，연소지속기축단。우화점화정시유리우획득량호적경제성화배방성절중효과，재중저부하시우위명현。
On a retrofitted methanol engine with 17 .5 compression ratio ,intake throttle ,intake port injection and spark igni-tion ,the influences of ignition timing on combustion and emission characteristics in 1 400 r/min were investigated .The results show that the methanol engine can run stably at the ignition advance angle of 18°BTDC ,15°BTDC and 12°BTDC .However , the maximum ignition timing delays with the load increase due to the limit of engine knock .With the increase of load ,the igni-tion delay period shortens and the maximum in-cylinder pressure and heat release rate increase obviously .With the advance of ignition timing ,the combustion process advances ,the maximum in-cylinder pressure and heat release rate increase ,and the combustion duration decreases .Therefore ,the optimized ignition timing can bring about a good compromise of economy and emission especially in low and medium load .