The effect of changing EGR rate on engine performance under different ammonia/methanol ratios

To improve the problem of high NOx emissions in ammonia/methanol engines, this article explores the impact of different EGR rates on engine performance under three different ammonia/methanol mixing ratios through simulation research. The research results indicate that when the proportion of methanol in ammonia fuel is small, the power and economy of the engine significantly decrease after increasing the EGR rate, and the density of unburned ammonia and N2O in the waste gas grows markedly. When the proportion of methanol in ammonia fuel is high, the decrease in engine power is relatively small after growing the EGR rate, and the density of unburned ammonia and N2O in the waste gas modestly grows. The introduction of EGR rate will reduce the overall performance of the engine, but the effect of reducing NOx emissions is very significant. By increasing the proportion of methanol in ammonia fuel, the adverse effects of EGR technology can be reduced. A60/M40/EGR12 % is the optimal combination of ammonia/methanol mixture ratio and EGR rate in this study. In previous studies, the combustion modes of ammonia/hydrogen fuel, ammonia/natural gas fuel and ammonia/methanol fuel all have the problem of high NOx emission. The research results of this paper can provide solutions and data support for such research.