Research On The Mechanism Of Hydrogen Fueled Engine’s Abnormal Combustion

When used for vehicle engines hydrogen has a fast burning speed, wide range ofsparking, low ignition energy and so on, these make the hydrogen fueled engine haveits unique advantages when compared with the traditional fossil fueled engine. Buthydrogen fueled engine still exists many problems, for example in hydrogen fueledengine the phenomena of abnormal combustion like preignition, temper, combustionpressure fluctuations and rough running occur easily. These hinder the developmentof hydrogen fueled engine seriously. So based on the method of combining thenumerical simulation and theoretical analysis together and use the thought ofintersection to put forward the conditions when preignition happens, this study do theresearch on the mechanism of abnormal combustion in hydrogen fueled engine. Thisresearch provides certain theoretical basis for improving the hydrogen fueled engine’scombustion performance and reducing its abnormal combustion.According to the actual hydrogen fueled engine and using the3D fluid analysissoftware AVL-FIRE, then the3D simulation model of hydrogen fueled engine isestablished in the study. The simulation model can simulate the normal work processof the hydrogen fueled engine. Using this model the influence on the state parametersin hydrogen fueled engine’s cylinder which caused by the different initial pressure,initial temperature, speed, spark advance angle and equivalence ratio aresystematically researched in this study. The main factors which impact the stateparameters in cylinder are determined. Then the conditions of which the preignitionoccurs in the cylinder are put forward, establish the relationship between stateparameters in cylinder and preignition, and the changes of state parameters which onthe influence of preignition are discussed later. Based on the analysis of2D curvesand color cloud pictures about the computed result (including temperature, pressure,velocity filed and so on) when preignition happens and combining with thecomparative analysis of the NOXemission in cylinder, the influence of hydrogen fueled engine’s combustion performance which caused by preignition is studied in thepaper.The results show that compared with the other three factors, spark advance angleand equivalence ratio have greater effect on the changes of state parameters.Preignition makes the hydrogen mixture which in cylinder ignited early, then thepoints when pressure and temperature in cylinder rising rapidly are well in advanceand the peaks of them also make some increase, the engine efficiency is greatlyreduced, the earlier preignition leads to the generation of engine tempering, eventuallymakes the hydrogen fueled engine parking. The preignition also makes the productionof NO increased, and will bring adverse effect to the environment, etc.