Study on the effect of structural optimization of TCD combustion chamber on engine performance under plateau environment

Abstract

The geometry of diesel engine combustion chamber directly affects the fuel atomization and combustion process. In order to meet the increasingly stringent emission regulations, this study took a certain model of diesel engine as the object, and used AVL FIRE 2020 R1 software to optimize the geometry of the prototype ω-type combustion chamber under the premise of unchanged compression ratio (CR). A TCD (T: turbocharged, C: charger air cooling, D: diesel particulate filter) combustion chamber with center boss structure and protrusion structure was designed, and the structural parameters of the TCD combustion chamber were further optimized. The computational fluid dynamics (CFD) method was used to analyze the effects of different combustion chamber geometries on the performance and emission characteristics of diesel engines. The results show that the combustion performance of the TCD combustion chamber is mainly affected by the combustion chamber diameter. Too large or too small a combustion chamber diameter will reduce the indicated power. The indicated power of the optimized TCD combustion chamber is 0.98% higher than that before optimization, and 8.26% higher than that of the ω-type combustion chamber. In addition, the soot emissions of the optimized TCD combustion chamber are reduced by 67.33% compared with the design before optimization, and 88.46% compared with the ω-type combustion chamber.