Efficiency comparison of hydrogen fuelled IC engines with gasoline- and methanol fuelled engines

One of the advantages of hydrogen as a fuel for IC engines is its high efficiency, certainly at low to mid load conditions, comparable to the efficiencies of diesel engines. Main reason for this is that the engine can run very lean, and that therefore the load can be regulated with the air-fuel ratio. This way the engine runs with wide open throttle for most of the time, avoiding throttle losses. For higher loads, the efficiency starts to decrease due to the increasing heat losses, which are more pronounced than for any other fuel. Efficiency comparisons are made at two test rigs in the laboratory of Transport Technology. A four cylinder production engine and a one cylinder research engine. Extensive experiments are done to compare the efficiencies of hydrogen and gasoline, as a function of engine speed and load for stoichiometric and lean conditions (for hydrogen), for variable inlet valve timing, for exhaust gas recirculation and supercharging (also for hydrogen). The most interesting results are shown and the differences for the efficiencies between the different fuels and for the different engine operation settings are explained. Recently, experiments have started on methanol and the efficiencies are compared as well. Methanol is an interesting alternative fuel, which can be produced in a sustainable way from hydrogen.