A study of the output characteristics of electric fuel pumps during artificial fault simulation

The electric fuel pump (EFP) is one of the potential sources of fuel system failures. According to various data, the fuel system accounts for 25...50% of all failures. The most common reason for the impairment of the fuel system performance and, in particular, the failure of the fuel pump is the contamination of fuel with large or small particles, as well as the wear of the structural elements of the EFP. The purpose of the study is to determine the technical condition of electric fuel pumps of motor vehicle engines based on the use of testing technologies. The paper discusses theoretical and experimental studies of the fuel system of motor vehicle engines: the change in the current consumption rate of the EFP depending on the degree of contamination of series elements in the system and leaks in the injection unit of the EFP.

Experimental and numerical analysis of fluid-solid-thermal coupling on electric fuel pump

This paper designs an axial partition fuel cooling shell to solve the problem of temperature rise in the motor of the electric fuel pump (EFP). And describes a simplified method in conjunction with the computational fluid dynamics(CFD) to analyze heat generations and fuel cooling effects in integrated EFPs. Furthermore, CFD is used to numerically simulate the coupling effects among the fluid-solid-thermal based on multiple physical field. With varying different working conditions of the pump, cooling characteristics of the fuel cooling shell are obtained through CFD results. Finally, an experimental system for the EFP is established to verify reliability of the simplified method and the effectiveness of the fuel cooling scheme. Results show that fuel cooling shell plays an essential role in heat dissipating, with a maximum reduction of up to approximately 42 K in temperature. Temperature error between simulations and experiments is less than 4%, which indicates reliabilities of the simplified model and fuel cooling shell.

AUTOMOTIVE ELECTRIC FUEL PUMP’S FAULTS: RESULTS OF THE PHYSICAL MODELING

Introduction. A significant proportion of the fuel pump’s faults is associated with an electric motor (about 40%), the technical condition of which is determined by the value of the electrical resistance of the winding circuit. However, direct measurement of electrical resistance without removing the vehicle is difficult. Therefore, it is possible to diagnose the performance of the electric motor (and the pump as a whole) by the amount of consumed current.Materials and methods. The author used physical modeling of faults by adjustable resistance for acceleration of the experiment and establishment of precise limits in the efficiency of the electric motor. The criterion for the operability of an electric fuel pump was the value of the developed pressure of at least 0.25 MPa.Results. An increase in the series-connected resistance led to a decrease in the current consumption of the pump, as well as a decrease in its performance. When the critical resistance value reached 11.2 ohms, the pump stopped working. A decrease in the resistance connected in parallel also led to a decrease in the current consumed by the pump since a significant part of it is bypassing of the electric motor through resistance. When the critical resistance value of 0.2 Ohm was reached, the pump stopped working.Discussion and conclusions. As a result, the author develops the mathematical model of the electric motor’s efficiency, which allows determining its technical condition by the usage both the value of electrical resistance and the consumed current. Moreover, measuring the current consumed by an electric motor serves as the basis for diagnosing electric fuel pumps directly on a vehicle and reduces the labor intensity and downtime of vehicles under repair.

Development of the Electric Fuel System for the More Electric Engine

This paper describes the experimental rig test result of the electric motor-driven fuel pump system for the MEE (More Electric Engine). The MEE is an aircraft engine system concept, which replaces conventional mechanical/hydraulic driven components with electric motor-driven components. Various MEE approaches have been studied since the early 2000s and one of its key concepts is an electric motor-driven fuel pump [1–4]. The authors commenced a feasibility study of the electric motor-driven gear pump system for what was assumed to be a small-sized turbofan engine. The concept study and system design were conducted, whereupon technical issues for the electric fuel pump system, which both supplies and meters fuel via the motor speed control, were clarified [5, 6]. Since one of the key issues is fuel-metering accuracy, the electric fuel system, including a flow feedback closed-loop control, was designed to ensure accurate fuel-flow metering for aircraft engine applications. To verify the rig system, an experimental model of the electric fuel pump system is assumed for a small-sized turbofan engine. The hardware of the motor-driven fuel pump and flow measurement mechanism, including an FPV (Fuel-Pressurizing Valve) and orifice, were designed, manufactured and fabricated and a differential pressure sensor for flow feedback was selected. Other equipment was also prepared, including a motor controller, power source and measurement devices, and the entire rig set-up was constructed. A bench test using the rig test set-up was conducted to verify the fuel-metering accuracy, response and system stability. Data, including the static performance and frequency response, were obtained for the electric motor, motor-driven fuel pump and entire fuel system respectively. The rig test results indicate the feasibility of the system, which will provide an accurate engine fuel flow (Wf) measurement and frequency response required for actual engine operation, via an electric motor speed control and fuel-flow feedback system, as proposed in the MEE electric fuel system.