Numerical Simulation Of The Biogas Engine Combustion Characteristics

With the increasing of global energy crisis and environmental pollution, more and more people take more attention to the biogas because of its clean and renewable characteristics. In recent years, biomass gas engine use for power generation is becoming a hot topic. But there are not many research about biogas engine both at home and abroad. This thesis uses the numerical calculation to analyze the unique combustion characteristics of biogas engine because of the situation.Firstly, this thesis establishes a biogas engine simplified three-dimensional geometric model, then the thesis uses the numerical calculation to analyze the combustion process of the biogas engine. The findings indicate that the combustion of biogas engine consumes a long time, which will lead to the power lower than natural gas combustion engine, but the emission performance is superior to the natural gas engine.This thesis uses the numerical calculation to analyze the fire nuclear generation and development process. Then use the single variable method to study the ignition system parameters, such as different ignition energy, spark plug gap and initial conditions such as the initial temperature, initial pressure and swirl ratio effect on biogas engine ignition performance. The results showed that the biogas engine ignition performance is poor, only when increase the spark plug gap with the ignition energy to improve the ignition performance of the internal combustion engine; when the ratio is increased, the gas can be preheated significantly enhance the performance of biogas engine, and the initial pressure, vortex little effect on ignition performance ratio.Finally, the influence of structural parameters of the combustion chamber squish mouth biomass combustion gas engine performance. Providing that increasing the combustion chamber squish area can enhancing biomass gas engine power, which indicates the direction of optimizating the biogas engine combustion chamber shape.The research results not only show the ignition and flame propagation characteristics of the biogas engine, but also show the influence of the shape of the combustion chamber squish mouth. The results can provide theoretical support for the development of biogas engine.