Single-Cylinder Testing of a High-Pressure Electronic Pilot Fuel Injector for Low NOx Emission Dual Fuel Engines: Part II—Optimization, Startability, and Inflammability Testing

Abstract

Single-cylinder testing of an Electronic Pilot Fuel Injection (EPFI) system (reported in Part I) indicated that a 45 percent reduction in NOx emissions could be obtained with a 3 percent improvement in fuel consumption by replacing the mechanical system, delivering 6 percent pilot, with the EPFI at 2.9 percent delivery. Further optimization testing of this system at pilot levels down to 0.7 percent over a wide range of timings and air/fuel ratios resulted in even further reductions in NOx emissions without fuel penalty. The EPFI system can yield NOx emissions levels significantly below 2 g/BHP-h with an improvment in fuel consumption of at least 3–4 percent, and probably yield emissions level as low as 0.5 g/BHP-h without substantial penalties in efficiency or operability.