Electronic Fuel Injection for Hydrogen Fueled Internal Combustion Engines

This paper describes an evaluation of a series of commercially available natural gas fuel injectors, originally designed for heavy-duty diesel application, for use with hydrogen fuel in an electronic fuel-injected internal combustion engine. Results show that sonic flow, pulse-width-modulated electronic gaseous fuel injectors provide accurate and stable metering of hydrogen gas at fuel pressures between 25 and 200 psig. A linear flow rate of hydrogen was observed with a low standard deviation error during pulse width modulation. Plots of flow rate of hydrogen (mg/injection) versus pulse width (PW) are presented for inlet pressures from 25 to 200 psig for selected injectors. In addition, injector response tests were conducted and found to have time delays (time it takes the injector to open) between 2.6 ms and 2.3 ms at 25 psig inlet pressure. Time-delay times increased linearly between 4.0 ms and 3.0 ms at 200 psig. In addition, leak tests were performed on all injectors and the measured leak rates were found to be insignificant. The precise metering of fuel is critical for the performance of hydrogen powered engines. The performance of the injectors evaluated was within the necessary tolerances for hydrogen applications with internal combustion engines.