| With the rapid development of social economy and the sustainable growth of global car ownership, human demands for oil were growing. In addition, with the emission regulations each country has made are increasingly stricter, the car’s engine, as the main force driving, was facing more and more severe challenges. H2 was usually considered to be the most potential alternative energy of car for its clean, efficient and renewable, but natural gas mixture of hydrogen fuel(HCNG) was the most feasible scheme of hydrogen in engine applications, which had very important real value to alleviate the energy crisis and reduce harmful emissions from automobiles.Firstly, this paper theoretically calculated different HCNG theory air-fuel ratio, volume calorific value, density and calorific value. Then on the basis of GT-suite software, it established HCNG fuel depot and a domestic YC4 G type natural gas engine simulation model, tested them, and calibrated the accuracy of the simulation model.Secondly, in order have a clear understanding of the influence rules of different HCNG on engine performance, this paper compared and analysed the combustion process of five kinds of HCNG in different hydrogen mixing ratios, the result showed that adding hydrogen in natural gas, compared with natural gas, could decrease engine power performance, make the economic performance get better, rise the pressure and combustion temperature, make the combustion starting point in advance and increase the peak value of heat release rate; With the hydrogen mixing ratio increasing, NOx and CO emission increased and HC emission decreased. Through this comprehensive analysis, we may come to the conclusion that when the hydrogen blending ratio is 20%, the performance of the engine will reach a better level.Finally, the engine was studied with HCNG20 by variable parameters such as excess air ratio, ignition advance angle and valve overlap angle. The results showed that, based on the study of the excess air coefficient and ignition advance angle, the paper mainly analyzed the interaction of power performance, economic performance and emission performance of engine, finally the MAP diagram of HCNG20 of each property was obtained; When studied on the different valve overlap angle, this paper used two different air distribution schemes, when the better engine dynamic performance was needed, we should fix the early intake valve open angle, change the late exhaust valve closing angle, on the contrary, change the early intake valve open angle and fix the late exhaust valve closing angle, the engine would obtain the better emission performance.Through this research of the burning HCNG’s influence on engine performance, on the one hand, the paper showed that HCNG as an alternative fuel has a good application prospect; On the other hand, it also provided the reference of HCNG’s application in gas engine optimization for further improvement. |
