Studing On Characteristic Of Multiple Injections For Double Valves Electronically Controlled Fuel Injection System

As the environmental pollution and energy shortages have become increasingly prominent,applying the advanced electronically controlled fuel system to diesel is imminent.Double-valve electronically controlled fuel system with its characteristics of flexibility in injection laws and greatly freedom of control can meet the requirements of diesel.Multiple injections is the important mean for reducing emission and improving the fuel economy of diesel.Therefore,the purpose of studying multiple injections of double-valve electronically controlled fuel system is not only to provide the theoretical basis for the design and optimization of the system,but also to improve the matching consistency between fuel injection system and diesel.This paper analyzes the working principle of the double-valve electronically controlled fuel system,and establishes a comprehensive numerical simulation model of system in AMESim environment,combined with experimental researching to calibrate and validate the numerical model.Through comparing of relevant experimental and computational data,the results indicate that the accuracy of numerical model is greater than 92.6%,it can be used to study the characteristic of multiple injections for double-valve electronically controlled fuel system.It studies the influence mechanism of the main structural parameters of high-pressure part and control parameters to the fuel injection quantity and post-injection rates for three injections in fuel injection system.Obtaining that the post-injection quantity is influenced by the main injection pressure and main fuel injection quantity,oil return throttle aperture,oil sump volume,cam profile speed,main-post injection dwell pulse with are the key factors affecting post-injection quantity.In overall conditions,calculating the MAP of control parameters,when the pre-injection and post-injection quantities meet the requirements of diesel.Combined with low pressure oil-filled system,first of all,this research studies the influence rules of characteristic parameters to the oil-filled characteristic quantity such as negative pressure continued angle,pressure rise rate and so on at different speeds,while volatility and quantitative analysis were involved.Secondly,in overall conditions,it studies the mechanism of oil-filled characteristic quantity variation with speed and fuel injection pulse width.Finally,a further study on the stability of single and three injections in multiple cycles caused by the transfer of oil-filled pressure,revealing the key reasons leading to inconsistencies of injection characteristics in fuel system.