액상분사식 LPG 인젝터의 아이싱 생성 특성 및 억제 방법

• Published in: 한국분무공학회지 Vol. 14; no. 4; pp. 147 - 152
• Main Authors: 이선엽, Sun Youp Lee, 김창업, Chang Up Kim, 최교남, Kyo Nam Choi, 강건용, Kern Yong Kang
• Format: Journal Article
• Language: Korean
• Published: 한국분무공학회 30.12.2009; 한국액체미립화학회
• Subjects: Droplet after injection; Icing; Liquid-phase LPG injection; LPG 액상분사; 결빙; 기계공학; 후적; LPG
• ISSN: 1226-2277; 2288-9051

Since a liquid-phase LPG injection system allows accurate control of fuel injection and increase in volumetric efficiency, it has advantages in achieving higher engine power and lower emissions compared to the mixer type LPG supplying system. However, this system also leads to an unexpected event called icing phenomenon which occurs when moisture in the air near the injector freezes and becomes frost around the nozzle hole due to extraction of heat from surrounding caused by instant fuel vaporization. As a result, it becomes difficult to control air/fuel ratio in engine operation, inducing exacerbation of engine performance and HC emission. One effort to mitigate icing phenomenon is to attach anti-icing injection tip in the end of nozzle. Therefore, in this study, the effect of engine operation parameters as well as surrounding conditions on icing phenomenon was investigated in a bench test rig with commercially-used anti-icing injection tips. The test results show that considerable ice was deposited on the surface near the nozzle hole of the anti-icing tip in low rpm and low load operating conditions in ambient air condition. This is because acceleration of detachment of deposited ice from the tip surface was induced in high load, high rpm conditions, resulting in decrease in frost accumulation. The results of the bench testing also demonstrate that little or no ice was formed at surrounding temperature below a freezing point since the absolute amount of moisture contained in the intake air is too small in such a low temperature.