Numerical Simulation And Experimental Research On The Working Process Of The Biogas Engine

In this century two important problems facing to the world are environmental protection and energy crisis, so it is of necessity for the human being to search new "clean alternative fuels". In order to realize continuous development, China ought to search alternative fuels meeting the developing demands of our country. One of the most effective measures to transform biomass energy into clean energy with high quality is to gasify biomass, such as straw and sawdust. This kind of biogas can be used as the fuel of the internal combustion engine directly.It has connatural advantages for our traditional agriculture country to develop biogas engine. It can not only reduce the pollution of the waste biomass to the environment and secondary pollution produced by its incineration, but also weak the dependence upon the oil resource caused by the extensive use of engine during our national economic construction. However, the spark ignition engine that only adopts biogas hasn't been studied in our country. Since the calorific heat of the biogas is lower, it needs deep research to find out if the biogas can be used for ICE without mixing into diesel oil or not.The spark ignition 4135-biogas engine was developed in this paper based on numerical simulation in view of the above circumstances. The experiment of the biogas engine showed that 4135-biogas engine had good dynamic, economic and emission performances.The working process of the engine was multidimensional and multiphase. So it was very difficult to study the complex process in detail, and most of the previous calculations were simplified. In this paper the geometry and mesh of combustion system were built without simplifying, and the working process was simulated.The visual results of three-dimensional flow-field, turbulence energy and flame front surface within the combustion system were obtained by calculation. The simulation results showed that the outer mixing intake manner was proposed for 4135-biogas engine in order to get homogeneous mixing of biogas with air; the arrangement of ignition position had an important effect on the expansion and...