FUEL SUPPLY CONTROL BY A BATTERY-TYPE SYSTEM TO REDUCE PUMP DRIVE LOSSES

Compliance with modern environmental standards and fuel efficiency requirements is a key challenge facing diesel engine manufacturers. To meet these challenges, measures are being taken to intensify fuel supply and enable flexible control of its parameters. To a large extent, these requirements are fulfilled by modern accumulator-type fuel systems (Common Rail (CR) systems). However, in such systems, a portion of the fuel delivered by the high-pressure fuel pump (HPFP) to the rail is excessive and is discharged back to the fuel tank through a pressure control valve. Consequently, part of the mechanical energy consumed to drive the HPFP is lost, which negatively affects the engine’s efficiency and environmental performance. These power losses are especially significant in small-displacement engines, which necessitates measures to reduce them. This article presents the results of a literature review on the level of mechanical losses in the drive of high-pressure fuel pumps in diesel engines, the methods of regulating HPFP output under various engine operating conditions, and the rationale for controlling the delivery rate of the HPFP in accumulator-type fuel systems to reduce mechanical drive losses. Based on the conducted analysis, it is concluded that in order to reduce power losses in the HPFP drive and thus increase the mechanical and overall efficiency of diesel engines with accumulator fuel systems it is necessary to include a device in the fuel system that enables delivery adjustment independently of pump shaft speed and accumulator pressure. Future work will focus on developing a conceptual design of an HPFP that enables reduction of mechanical losses through controlled delivery, as well as on creating mathematical models required to describe and study processes within the diesel fuel system.