Comparisons of the Ignition Voltage Requirements of Natural Gas and Gasoline in a Bi-Fuel Passenger Car

Optical study on the effects of the hydrogen injection timing on lean combustion characteristics using a natural gas/hydrogen dual-fuel injected spark-ignition engine

“…Meanwhile, its good anti-knock property can make engines run at higher compression ratios [3], and high compression ratio is always combined with large excess air coefficient or residual burnt gas to increase thermal efficiency [4,5]. However, natural gas engines often suffer from slow burning rate and large cycle-to-cycle variations, which causes high exhaust temperature and low thermal efficiency in comparison to traditional gasoline engines [6]. The slowburning velocity can be improved by mixing with the fuel with faster burn rate like hydrogen [7e9], whose minimum ignition energy (MIE) value (~0.02 mJ) is much smaller as compared to methane (~0.28 mJ) [10], and the laminar flame speed is seven times higher than methane under stoichiometric conditions [11].…”