Near-term introduction of hydrogen engines for automotive and agricultural application

Hydrogen is a versatile fuel with the unique potential of providing an ultimate freedom from an energy (fuel) crisis and environmental degradation. This paper describes some aspects of a series of experimental studies carried out in several configurations of hydrogen-operated engine, keeping in view the possibility of introducing hydrogen engine into the existing energy infrastructure. Optimum performance and low-emission characteristics have been experimentally identified and steps have been identified to get rid of undesirable combustion phenomena such as backfire, pre-ignition, knocking and rapid rate of pressure rise. As far as the introduction of hydrogen engine into the transportation sector is concerned, fuel-induction technique forms the most important aspect of development. Our studies show that timed manifold injection (TMI) has the potential of being the most appropriate fuelling strategy. A TMI-operated engine does not need any substantial modification in the existing system hardware and ensures high thermal efficiency and low specific fuel consumption without any symptoms of undesirable combustion. Experimental investigations carried out with a typical multi-cylinder automotive engine adopting exhaust gas recirculation (EGR) indicate that the NOx emission level can be drastically reduced over a wide range of operating conditions. Considering the prospects of introducing hydrogen engine into the agricultural sector or a decentralized energy units, this paper also deals with the performance improvement achieved by way of hydrogen substitution in a small horsepower diesel engine widely adopted in rural/agricultural sector of developing countries. It has been experimentally observed that the range of smooth engine operation can be increased and the level of energy contribution in such systems can be substantially enhanced by adopting a charge dilution technique.