Title: Optimizing the design of a hydrogen engine with pilot diesel fuel ignition

Authors: S.M. Lambe, H.C. Watson

Addresses: Mechanical and Manufacturing Engineering Department, University of Melbourne, Parkville, Victoria 3052, Australia. ' Mechanical and Manufacturing Engineering Department, University of Melbourne, Parkville, Victoria 3052, Australia

Abstract: A diesel engine was converted to dual-fuel hydrogen operation, ignition being started by a |pilot| quantity of diesel fuel but with 65 to 90% of the energy being supplied as hydrogen. With later injection timing, use of delayed port admission of the gas, and a modified combustion chamber, thermal efficiencies were achieved nearly 15% greater than those for diesel as the sole fuel. A |solid| water injection technique was used to curb knock under full load conditions when the power output equalled or exceeded that of a similar diesel engine. The indicator diagrams under these conditions closely approach those of the Otto cycle. The development was assisted by computer simulation using a novel self-ignition and flame propagation model. The very fast burning rates obtained with stoichiometric hydrogen-air mixtures show combustion to occur within 5 degrees of crank rotation yet Otto cycle thermal efficiency was not achieved. However, greenhouse gases are shown to be reduced by more than 80%, nitrogen oxides by up to 70%, and exhaust smoke by nearly 80%.

Keywords: burn rate profile; combustion duration; combustion modelling; cylinder pressure data; diesel engines; dual fuel; emission control; exhaust emission; greenhouse gases; GHG emissions; hydrogen; simulation; self-ignition; flame propagation; water injection; nitrogen oxides; exhaust smoke; NOx; hydrogen-air mixtures; vehicle design.

DOI: 10.1504/IJVD.1993.061844

International Journal of Vehicle Design, 1993 Vol.14 No.4, pp.370 - 389

Published online: 28 May 2014 *

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