Spray Penetration Analysis of a Common Rail Injector with Different Injection and Back Pressure

摘要

Common rail injection system has established as an effective fuel injection technology for diesel engines. The technology is technically acceptable, environmentally friendly and economically viable due to its variant of direct fuel injection at high pressure. In this regard, nozzle design in common rail injector requires injection technology that is capable of improving driving performance and fuel efficiency as well as meeting the clean environment requirement by reducing the emissions and operating engine noise. In this study, a common rail injector of 14 holes with swirl effect has been introduced. The nozzle components include 14 holes, a helical type swirl spray unit, a spray unit support and a nozzle cap. Application of these attachments aims to deliver significant idle quality, flow consistency and durability that are essential for high performance electronic fuel injection. Spray penetration of the injector with swirl effect is investigated here with 300 bar and 600 bar injection pressure with different back pressures (ambient pressure) of 1 bar, 15 bar and 30 bar. Spray penetration is observed as macroscopic images that viewed from front and side portions of the chamber. It is found that the spray tip penetration is inversely proportional to back pressure with respective to different injection pressure in different time after start of injection (ASOI) in microsecond scale.