Rotating injector in DI diesel engine for improving performance and reducing NOx emission

Oxides of Nitrogen are the major emission from a diesel engine. It is due to heterogeneous diffusion combustion system with fuel-rich regions, which produce high local temperature around the periphery of the spray where high formation rate of NO is promoted. Various techniques are therefore employed to reduce the NOX emission like EGR, SCR, etc. In this present work a rotating injector is a technique used for improving performance and reducing NOX emission in a direct injection diesel engine. The conventional stationary injector is replaced by the rotating type of injector to spray the fuel inside the engine cylinder. This rotating injector is functionally modified injector to achieve the rotary motion of the injector during injection. The fuel injector is rotated during the fuel injection which creates a fuel swirl motion inside the cylinder. The emission and performance of a single cylinder diesel engine using modified rotating injector at various loads are studied. The investigation reveals reduced NOx emission and marginal improvement in performance of the engine due to decrease in breakup length of spray and increase in the spray area during injection. The rotating spray makes co-swirl motion along with air swirl motion inside the cylinder at the end of the compression. The finer fuel is sprayed throughout the combustion chamber, enhances the air fuel mixing process. It increases the burning rate and reduces the local concentration of the mixture. As a result, there is an improvement in performance and a simultaneous reduction in NOX emission from the engine.