Investigation On Injection Characteristics Of Double Valves Fuel System With Electronically Controlled

Achieving high efficiency and clean combustion, it not only need reasonable intake andoptimizing the structure of the combustion chamber, but also need the injection system haveappropriate injection pressure, injection timing and injection fuel quantity, the Double valveelectronic-controlled fuel injection system can not only realize high fuel injection pressure,flexible and controllable injection timing and the precise injection quantity control, but alsohas the more flexible characteristics and can change the nozzle opening pressure by cycles inany conditions, which is one of the key development direction of diesel engine fuel injectionsystems coping with future more stringent emission regulations.A double electronic valve fuel system is established based on an general electronic unitpump in this paper, fuel injection characteristics analysis of this double valve system wasdone with the combination of experiment analysis and Ageism software numerical simulation.According to the research, it provides the foundation and reference for the system’sdevelopment、application and other similar changes of the fuel injection system. The majorresearch work and relative achievements of this paper can be summarized as follows:Schematic and principle of this fuel system is studied firstly.on the basis of this,theAMESim simulation model was established.By the comparison between the numericalsimulation and experiments under the SCV control model,it is concluded that the AMESimsimulated model can precisely estimate the fuel injection system parameters under alloperating conditions.so it can provide the platform for the system characteristics analysis.In order to guarantee the effect of injection characteristics of double valve system underdifferent control parameters,this paper analyzed cooperative controlling injectioncharacteristics of double valve system and grasped its main technical characteristics with anexploratory control strategy,predicted its injection characteristics under different controlmodel.Compared with the genneral electronic unit pump,it is found that the double valvesystem can change the Nozzle Opening Pressure(NOP)by cycles in any conditions and has theflexible multiple-injection characteristic.Considering the double valve system keeping the consistency and stability ofperformance in the process of production and matched calibration, the research of the keyfactors on injection characteristics is spread in the double valve system within the scope of the condition of the different control mode. First of all, since injection characteristics is basicallyinfluenced by cam velocity plunger diameter, high-pressure pipe diameter, high-pressure pipelength and orifice diameter,which are injection pressure,cycle fuel quantity and injectionduration,the response analysis and correlation analysis of them were executed.Secondly,thequantitative percentage index of the influence of different parameters on cycle injectionquantity variation was obtained by quantitatively analyzing.the variation law of correlationbetween different parameters and cycle injection quantity variation under parametersinteraction or not in the overall operating conditions was revealed respectively;Finally,todeeply analyze system performance, the linearity analysis of fuel injection system wasperformed through modern control theory. From the above analysis, the results offer theguarantee to the stability and consistency of the injection performance in the double valvesystem.