In order to estimate the air-fuel ratio of hydrogen fueled engine by using exhaust gas analysis, single cylinder engine test with gas chromatography was carried out and the experimental results were compared with calculated ones. At the same time universal exhaust gas oxygen sensor which is commonly used for gasoline fuel was also introduced to hydrogen fueled engine.
As a consequence, it is evident that unburned hydrogen discharges into exhaust pipe in the vicinity of stoichiometric fuel-air equivalence ratio and discharged hydrogen results in the error of fuel-air equivalence ratio estimation. Also exhaust oxygen sensor is largely affected by hydrogen. Therefore proper correction shall be introduced to calculate the fuel-air equivalence ratio precisely.