Effects of fuel temperature on injection performance of an EUP system

Abstract

The fuel temperature has a great influence on the characteristics of an electronic unit pump (EUP) system, especially on the injection performance. This paper studies the regularity of the high-pressure fuel supply system performance at different fuel temperatures. The injection quantity, the injection rate, the fuel pressure, and the needle lift were measured by the EUP system test bench. Investigation results showed that, with the increase of fuel temperature, the injection quantity and maximum injection rate decreased, the time of start injection was delayed, and the peak fuel pressure value decreased. For the needle valve, as the temperature was raised its closing time was advanced at low speed conditions but delayed at high speed conditions. In addition, the empirical equations for the fuel temperature effects on the circulating fuel injection quantity and peak pressure are proposed by the experimental test and simulation data. This study will help to further apply and study the engine, and provide a reference for engine fuel supply control system design.

Research On Fuel Compensation Control of High-pressure Common-Rail Diesel Engine Based On Crankshaft Segment Signals

“…It is important to control the fuel quantity accurately to improve the performance of diesel engine [14][15][16][17] . The nonuniform fuel supply deteriorates the fuel injection control so that the diesel engine cannot produce the same torque in all cylinders even if the injection time is the same, the torque contribution of different cylinders is different 18,19 .…”