The Benefits of High Injection Pressure on Future Heavy Duty Engine Performance

Abstract

Diesel fuel injection pressures have increased steadily on heavy duty engines over the last twenty years and pressures as high as 300MPa are now possible. This was driven by the need to control toxic exhaust emissions, in particular particulate emissions using advanced in-cylinder combustion strategies. With the introduction of efficient aftertreatment systems for both particulate and NOx emissions control there is less demand for in-cylinder emissions control especially considering the drive for improved fuel economy. In this paper we consider the benefit of high fuel injection pressure for a number of emissions control strategies with different balances of in-cylinder and exhaust aftertreatment emissions control. A test program was undertaken on a single cylinder heavy duty research engine installed at the University of Brighton, in collaboration with Ricardo. The engine was fitted with the Delphi F2E fuel injection system capable of 330MPa injection pressure and multiple fuel injections. The engine intake system was configured to give independent control of the intake pressure and EGR rates, achieving rates of up to 50% at high engine loads. The benefit of high injection pressure was investigated under a number of strategies for achieving Euro VI emissions levels. The trade-off of controlling NOx emissions using EGR rate and aftertreatment on engine performance and Total Cost of Ownership (TCO) was investigated. Finally, the benefit of a simple split injection strategy at high rail pressure was studied.

Effect of Hydrogen Fumigation in a Dual Fueled Heavy Duty Engine

“…This is indicative of good air-diesel fuel mixing, and high air utilisation. A fuel injection pressure of 2000 bar was selected for the current work, based on a previous extensive optimization study [15]. Although lower than the 3000 bar capability of the F2E system, this pressure provided the best result at the A50 condition.…”

Experimental investigation on the effect of injector hole number on engine performance and particle number emissions in a light-duty diesel engine

“…The latest fuel injection equipment (FIE) can obtain up to 250 MPa injection pressure for light-duty and up-to 300 MPa for heavy-duty compression ignition (CI) engines. 10,11 Effects of higher injection pressure on heavy-duty diesel engines have been studied in detail, [12][13][14] and researchers have also tried to figure out the optimum injector geometry for diesel engines which produces the best combustion characteristics with minimum emissions. 13,15 Some researchers have reported that increasing the injector hole number while decreasing the hole diameter helps in particulate matter (PM) reduction because of better fuel atomization and mixing with air while few others have suggested that increasing injector hole number has an adverse effect on PM-NOx trade-off especially when operating at high load condition.…”

Why we should invest further in the development of internal combustion engines for road applications

“…The higher injection pressure also influences a more uniform atomization of fuel. High injection pressure enhances cavitation formation inside the injection nozzle, which influences a better spray break up process and higher fuel velocity at the nozzle exit [19][20][21]. Fuel spray formation and break up processes are also influenced by the number of injection holes and shape of the nozzle sac volume [22].…”