Effect of hydrogen addition on performance of low heat value gas engine

Experiment of low heat value gas blended with hydrogen in a modified single-cylinder CNG engine is studied. The components of low heat value gas contain natural gas and N2, the natural gas contents from 60% to 80% by volume, N2 content is from 20% to 40% by volume. The hydrogen blending ratio is from 10% to 30% by volume. Results show that with the increase of N2 proportion, the engine power, CO and NOx emissions are decreased, but HC emissions is increased. When hydrogen blending ratio is increased, CO emission is increased while HC emission is decreased. When properly increases hydrogen blending ratio, the maximum cylinder pressure and engine torque are increased. However, large hydrogen blending ratio will decrease engine power. NOx emission is related to N2 proportion of low heat value gas.