Study of the delivery behaviour of a pump for common rail fuel injection equipment

Abstract

This work deals with the delivery flowrate of a radial piston pump for common rail fuel injection equipment. At first, attention is paid to the volumetric efficiency of the pump, presenting basic formulas and reviewing common theory. A new efficiency model is proposed and considerations regarding the pump running under large pressure differences between suction and delivery and variable driving speeds are formulated in order to realize difficulties in pump filling. Later, a numerical model simulating the working behaviour of the pump is used to investigate the effects of variable inlet pressures under high delivery pressure and different driving speeds. Comparisons between numerical results and experimental data referring to the delivery behaviour of the pump are reported, as well as in-cylinder pressure diagrams, necessary to realize filling deficiencies quickly. The flowrate delivered by the investigated pump depends on both the inlet and outlet pressures. Increasing the driving speed beyond certain values does not result in proportional flowrate at pump delivery.

Prediction of cavitation and induced erosion inside a high-pressure fuel pump

“…Two variations of the configuration were considered, bearing different port-hole designs, in order to verify which one achieved higher dosage accuracy designated by the extent of bubble growth in the pump chamber. Giuffrida et al 12 investigated, in terms of liquid delivery efficiency, the operation of a radial positive-displacement pump comprising three separate pressurization chambers and three plungers connected through a common cam ring. It was verified that the delivered flow rate decreased with increasing values of the pump driving speed and constant delivery pressure.…”

Influential factors’ correlation analysis upon common rail system fuel injection quantity for diesel engines

“…The common rail system is an advanced technology which meets the stringent diesel engines' emission standards and satisfies consumer demand for better fuel efficiency and increased power. 1,2 Comparing with the other fuel injection system, the common rail injection system has advantages such as higher injection pressure, more flexible and adjustable fuel injection rate and injection timing. 3,4 The variations in the parameters of the injector have significant effect on the injection characteristics and result in the inconsistency of the fuel injection quantity which is critical for the stability of the system.…”

Theoretical analysis and mathematical modelling of a high-pressure pump in the common rail injection system for diesel engines

“…Giuffrida et al. 16 proposed a new volumetric efficiency model in which the concept of delivery efficiency was introduced. This numerical model simulating the behavior of the pump was implemented in the AMESim environment, and the outputs were consistent with experimental results.…”

“…The volumetric efficiency loss caused by the inlet valve lag at the start of the compression stroke, the expansion of the fuel entrapped in the clearance volume, and the leakage was analyzed. Giuffrida et al 16 proposed a new volumetric efficiency model in which the concept of delivery efficiency was introduced. This numerical model simulating the behavior of the pump was implemented in the AMESim environment, and the outputs were consistent with experimental results.…”