Research On Simulation Of Electronically Controlled CNG Engine Gas Supply System

Since more than a hundred years has the automotive industry been developed, with thecontinuous progression of the human community, the automotive technology developsalso violently, and the tenure quantity increases correspondingly. With the step into newcentury, issues like global resource crisis and global warming became realistic for all thecountries. The end gas contamination became also more and more serious day by day.For this issue, all the countries are actively looking for substitutions of oil fuel forenvironmental protection and energy strategy target. Among them, the best option ofwhich is natural gas because of it’s large underground storage and less contamination.Based on which, the CNG drive automotive has been paid attention extensively.In electronic control CNG automotive motor, fuel supply system and ejection systemare the two most important parts. The fuel supply system supplies a pressure-steady gasthrough decompressor that decreases the gas pressure from the gas tank and stabilize thepressure in spray nozzle inside a certain limit during work. The ejection system providesthe fuel precisely by using electronic control unit. Currently the experimental procedureis commonly used to proceed the study on the supply and spray of gas of electroniccontrol CNG drive, whereas it is immature to study this issue with respect to thesystematic modeling.To handle the affection of structural parameters in the electronic control CNG motordecompressor to the decompressing characteristics, and the spray attribute in affection ofthe decompressor outlet pressure and manifold back pressure of the gas ejector, by usingAMESim engineering simulation software, the supply and spray simulation models ofincluding decompressor, gas ejector, pressure adjusting device etc. have been established.By using this simulation model and combining the knowledge of cybernetics, thejudgment to the decompressor pressure reduction stability and responsiveness has beencarried out. The variation of structural parameters like adjustable diaphragm, valve portdiameter, spring stiffness, outlet section area etc. of the simulative model to thedecompressing capability affection has been investigated. At the mean time, the study ofspray character under the effect of decompressor outlet pressure and manifold backpressure of the sprayer has also been conducted.The conclusion can provide an effective assistance and reference for the future workslike electronic control CNG ejection design, parameter optimization and car oil-gasmodification, which will be helpful to increase the productivity and shorten thedevelopment cycle of products in the future.