Effect of Common Rail System on Vehicle Engine Combustion Performance

A test bench is set up based on a CA6106 Direct Injection (DI) diesel engine equipped with ECD-U2. MAP calibration is accomplished using the online calibration software, combustion analysis software and data acquisition software. The precision, feasibility and reliability of software design are verified by the tests. The experiments indicate that Common Rail (CR) injection system has a great potential to decrease the emission and improve the performance of DI diesel engine. The experiments on function matching of CA6DE diesel engine are conducted. The structural parameters of injector, the structural parameters and swirl ratio of combustion chamber are improved and optimized. Using the high pressure CR electronically controlled system and corresponding measurement instruments, the fuel consumption and exhaust parameters are measured. The results show that a higher injection pressure, smaller injector core diameter, as well as a lower swirl ratio, a proper combustion chamber shape, and a delay in injection timing, can improve the mixing and combustion of fuel-air mixture, reduce harmful exhaust, and improve the overall performance of economy, power and exhaust.