Lh2v70 Engine Electronically Controlled Fuel Injection System, Fuel Injection And Ignition Control The Map Technology Research

The paper took Engine LH2V70 electronic controlled fuel injection system as the subject for the study, throttle-speed method of gas flow, before throttle fuel injection way and a combination control mode of air-fuel ratio open-loop and closed-loop were used in the system. The paper started the study from the engine structure and working principles of the system, focusing on output characteristics of the six sensors which were selected in the information collection system, and the fuel injector performance characteristics was also researched.Furthermore, through the mathematical model by theoretical calculation, the initial fuel injection pulse width MAP and initial ignition timing MAP matched to the LH2V70 engine were derived. During the study of fuel injection MAP, cylinder heat transfer numerical simulation showed that the meshed geometric model using FLUENT software can be calculated of the temperature change, the result was further used to establish the mathematical model of engine inflation factor, through the function of intake pressure, engine speed, throttle opening, the paper set up the initial model of fuel injection pulse width, and used MATLAB/Simulink to establish the fuel injection MAP; During the study of ignition timing MAP, firstly the paper created a two-zone combustion model to calculate the basic differential equations, and established a turbulent flame model. Basing on the two models, parameters was simplified, through a series of expressions, the paper derived the mathematical model of ignition advance angle, with the same programming to get the initial ignition MAP.Thirdly, on the basis of a combination of theory and experiment, the paper took an amendment on the initial MAP. It described the control types and requirements of engine operating conditions, under the condition, fuel injection pulse width and ignition advanced angle were corrected; followed by analysis the basic goals and methods of the MAP test system, the paper choose set-width method to obtain the fuel injection pulse width MAP and the ignition timing MAP on the engine test-bed. Through the comparison of theoretical calculation and test, the result proved mathematical modeling was feasible to get the initial MAP of electronic control system.