TOWARDS AN ULTRA HIGH EFFICIENCY HYDROGEN ENGINE, COMPARISONS WITH LPG AND GASOLINE

摘要

The goal of hydrogen engine research is to achieve highest possible efficiency with low NOxrnemissions. This is necessary for the hydrogen car to remain competitive with the ever improvingrnefficiency of conventional fuel’s use, to take advantage of the increased availability of hydrogenrndistribution for fuel cells and to achieve better range than battery electric vehicles. This studyrnexamines the effect of compression ratio (CR) and lambda (excess air ratio) on thermal efficiencyrnfor CRs of 13, 14.5 and 16. The results demonstrate that highest indicated thermal efficiency atrnultra lean condition of lambda around 2 at the optimum CR of 14.5 which was higher than forrnLPG by nearly 3 CRs. The efficiency, although comparable with or better than other goodrnhydrogen engine practice, did not increase much over LPG. This is explained by the expectedrnhigher heat transfer losses. At CR 14.5, and MBT spark and at frequently used torque and speedrnconditions in the NEDC, the highest brake thermal efficiency was 39.9 to 40.8% at a maximumrnindicated thermal efficiency of 48%.