WT615增压CNG电喷发动机燃烧特性数值分析

Numerical Simulation of Combustion in Turbocharged Electronically—Controlled Injection CNG Eengine WT615

以WT615 CNG发动机为模拟研究对象,采用KIVA-3V软件建立了多维软件计算模型,并验证了模型的准确性。在此基础上研究了主要结构参数——燃烧室形状对燃烧特性和整机性能的影响。研究表明,直口形燃烧室的动力性、经济性能最好,更加适用于该天然气发动机,但排放性能有待提高;缩口形燃烧室的整机性能次之,碗形燃烧室的动力性和经济性则较差,后燃现象严重,不适用于天然气发动机。

A multi-dimensional combustion model was used to investigate the combustion process in CNG engine-WT615, and the accuracy of this model was validated through simulation with KIVA-3V software. Based on this model, the effects of combustion chamber configuration upon combustion performance and engine performance were studied. The simulation results suggest that rectangle chamber is more applicable to CNG engine, which has the best performance in dynamic and econonfic efficiency, but it＇s emissions still need to be improved; the performance of engine with contracted chamber is not so good as the one with rectangle chamber; and the performance of engine with bewl chamber is the worst one in dynamic and efficiency, with seri- ous after-combustion phenomenon and doesn＇t apply to CNG engine.