Experimental Study of Air-Fuel Ratio Control Strategy for a Hydrogen Internal Combustion Engine

One of the most attractive combustive features for hydrogen fuel is its wide range of flammability. The wide flammability limits allow hydrogen engine to be operated at extremely lean air-fuel ratios compared to conventional fuels. Concepts for part-load operation of hydrogen engines have been proposed using quantitative control and qualitative control. This paper summarizes the steady-state test results by quantitative and qualitative air-fuel ratio control modes in a hydrogen internal combustion four-cylinder engine operated on an engine dynamometer. Based on the test results of engine efficiency and NOx emissions, a combinated air-fuel ratio control strategy for hydrogen engine is proposed.