Experimental Investigation of the Effect of Fuel Injection Timing and Injector Opening Pressure on Performance and Emissions Characteristics of a Turbo-Charged Diesel Engine Under 8-mode Testing Cycle

摘要

For compression ignition (CI) engines, two of the fuel injection parameters affecting the engine’s performance and emissionsformation, are fuel injection timing (FIT) and injector opening pressure (IOP). Other such parameters include the number ofinjections, rate of injection and injection pattern, etc. In the present study, a multi-cylinder, turbocharged, four-stroke, directinjection (DI) diesel engine was used to investigate the combined influence of FIT and IOP on performance and emissionscharacteristics. The experimentation was conducted for two IOPs (250 and 300 bar) with four FITs such as 20°, 23°, 26°, and29° before top dead center (BTDC) at different engine speed and load conditions. To obtain the emissions characteristics, theengine was tested in accordance with the 8-mode steady-state cycle. Moreover, 250 bar and 23° BTDC were the original IOPand FIT, respectively. For all IOP conditions, in comparison to the results with the original FIT, the advancement or retardationin FIT provided the negative results in terms of brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC).Increasing the IOP from 250 to 300 bar, improved the performance parameters for retarded and original FITs (20° and 23°BTDC) and caused the deterioration in performance for advanced FITs. In terms of emissions characteristics, filter smokenumber (FSN) and emissions of carbon monoxide (CO) and unburned hydrocarbon (UHC) decreased on advancing the FITand increasing the IOP. On the other hand, oxides of nitrogen (NO_x) and carbon dioxide (CO_2) increased on advancing theFIT and increasing the IOP for all experimental conditions. The maximum improvement in the performance of the enginewas observed at increased IOP with the original FIT. The original IOP with retarded FIT resulted in the minimum NO_x andCO_2 with a significant reduction in performance. Furthermore, improvement in performance and reduction in emissions wereobserved when the engine was operated at higher IOP and retarded FIT.