Low polluting, energy efficient C.I. hydrogen engine

Abstract

A diesel engine was converted to dual-fuel hydrogen operation, ignition being started by a ‘pilot’ quantity of diesel fuel, but 65–90% of the energy was supplied as hydrogen. Delayed port admission of the gas, later injection timing and a modified combustion chamber allowed 15% increase in efficiency. A ‘solid’ water injection technique was employed to curb knock under full load conditions when the power output equalled or exceeded that of the engine with diesel fuel alone. The indicator diagrams under these conditions closely approach those of the Otto cycle. The greenhouse gases are shown to be reduced by more than 80%, nitrogen oxides by up to 70%, and exhaust smoke by nearly 80%. These single cylinder engine test results and application of a vehicle simulation model allow forecasts to be made of the on-road performance of a converted diesel engine. Small energy gains are predicted with substantial reduction in emissions under urban and highway driving conditions.