Evaluation of the influence of fuel pressure pulsation in the Common Rail system on the economic and environmental performance of a diesel engine

BACKGROUND: At present, all the world’s diesel engine manufacturers have directed their development strategy towards reducing harmful emissions, improving fuel efficiency and increasing power per liter. To achieve this, using only the Common Rail system is not sufficient. It is necessary to apply new additional devices, such as an exhaust gas converter, an exhaust gas recirculation system, the injection of additional fluids together with diesel fuel, as well as to improve existing ones. Increasing the accuracy of fuel delivery for an injector will make it possible to adjust the engine fuel system more precisely, leading to a positive effect on all areas of development of the diesel industry.

In this article, the possibility of increasing fuel efficiency and reducing harmful emissions through exhaust gases of a diesel engine with a decrease in pressure pulsation in the accumulator of the Common Rail system is considered on the example of the D-442-59I-1 (4ChN 13/14) experimental four-cylinder diesel engine with a two-valve gas distribution system manufactured by Altai Motor Plant.

AIMS: Study of the effect of fuel pressure pulsation in the Common Rail fuel system on the economic and environmental performance of a diesel engine.

METHODS: On a non-motorized test rig, the dependence of the fuel delivery of the injector on the pressure in the accumulator was determined. To assess the effect of fuel pressure at the injector inlet on the performance of a diesel internal combustion engine, experimental designs of diesel engines were simulated using the specialized software. Theoretical studies have been carried out to assess the influence of fuel pressure in the fuel system.

RESULTS: Data have been obtained on the effect of fuel pressure fluctuations in the high-pressure line on the injector cycling, harmful emissions and fuel efficiency.

CONCLUSIONS: As a result of the study of the process of fuel supply and combustion in a 4CHN 13/14 diesel engine, it was found that with a pressure fluctuation range of 50 bar in the fuel accumulator, the concentration of wet NOx decreases by 11%. The concentration of solid particles increases to 13.4%, fuel efficiency deteriorates to 0.5% when the operating pressure of the fuel deviates 160 MPa in any direction from the set value.