Abstract
Keywords - Hydrogen Engine, Mixture Formation, Emissions, Efficiency, Specific Power
Abstract - Hydrogen is recommended by experts as the fuel of the future. A point currently still being discussed is whether the fuel cell or the hydrogen-drive reciprocating-piston engine is the better form of converting energy for the purpose of driving a vehicle.
The latest results of close cooperation between BMW Group Research and Technology and the Institute of Internal Combustion Engines and Thermodynamics of Graz University of Technology in Austria, prove that the hydrogen engine ensures progress not only from an environmental point of view, but also and in particular in terms of its practical value.
While the gradual improvement of conventional drive systems requires increasingly more complex and elaborate modifications, hydrogen allows a quantum leap in the ongoing development of the reciprocating-piston power unit.
Given its particular physical properties, hydrogen is able to fulfill apparent conflicts of interest in terms of emissions, efficiency and specific power all in one. Benefiting from extremely wide ignition limits and a very fast speed of combustion, hydrogen allows the highest standard of operating efficiency under quality control throughout the engine's entire range of operation. Direct injection of hydrogen, in turn, provides an even higher level of specific power than with a gasoline engine. In addition, variation of the injection starting point as well as injection of a certain share of the fuel directly into the flame provides specific torque superior to that of the diesel engine, without overloading the engine's individual components. And last but not least, this allows lowest nitric oxide emissions.
The overall context of these technical interactions and the potential of the hydrogen engine have been substantiated by measurements on a single-cylinder research power unit.