Investigation On Injection Characteristics Of High Power Electronic Control Injector With Low Return Fuel

Energy crisis and environmental pollution are two major social challenges that the world faced over the years.As a diesel engine with high energy consumption and large emission,it is urgent to effectively improve its techinque level,optimize its economic performance and reform emission targets.High-pressure common rail fuel injection technology is of great significance for the emission and economy of diesel engines.The electronically controlled fuel injector serves as the hot topic of the high-pressure common rail fuel injection system.With the single cylinder power of the diesel engine increases,the demand of large circulation fuel injection quantity and low-return fuel has become a key technical breakthrough in electronic fuel injector.In this paper,the concept design of a new type of electronically controlled injector is carried out.The numerical simulation is used to study the target injector from the four characteristic aspects,including the characteristic of injection,working efficiency,dynamic response and fluctuation characteristics of injection quantity of multiple injection cycle.First of all,in view of the design of high-power low-return fuel injector,with the help of hydraulic simulation software AMESim platform,a numerical simulation model of injector is established,which verify that the model meets performance simulation requirements.Based on this,the influences of common rail pressure and control pulse width on each injection performance were revealed.In addition,the characteristics of hydraulic efficiency is studied for the defined hydraulic efficiency of the injector over the full operating plane.Next,the influencing factors of the dynamic response of the low-return fuel injector are studied.The injector response is defined as four specific responses to the needle valve.The changes of the corresponding response of the solenoid valve,the control chamber and the needle valve components are mainly studied.The quantitative analysis method is used to calculate and evaluate the effect of each parameter on injector response which is significant.The results show that the diameter of throttle,the diameter of needle valve,the maximum lift of solenoid valve and the preload of solenoid valve have obvious influence on the opening response of injector.The diameter of throttle,the control part of solenoid valve and the diameter of needle valve have obvious influence on the shut down response of injector.Finally,the fluctuation mechanism of the circulating fuel injection quantity of the low-return injector and the influence characteristics are revealed.The fuel pressure fluctuation characteristics at the inlet of the injector were analyzed and the influencing factors were studied.The influence mechanism and characteristics of the cycle fuel injection fluctuation under the pre-primary injection and the main-after injection was also studied.The research shows that the fluctuation of fuel injection quantity in multiple injection cycles is the result of superposition of pressure fluctuation caused by two injection injections.In addition,the study also found that expanding the volume of pressure storage chamber,to some extent,can weaken the fluctuation of circulating fuel injection quantity.