Effect of hydrogen-blended natural gas on the performance of single burner of water heater

In order to study the influence of natural gas on the combustion characteristics of domestic gas water heater when the hydrogen blending ratio exceeds the general research range which considers the gas interchangeability theory, an experimental system is built in this paper, taking a unit of partial premixed burner commonly used in water heater as the object. The flame shape, burner temperature and flue gas emission of natural gas with hydrogen ratio of 0 ~ 40% in the case of controlled mixing with primary air under the heat load condition of 0.7~ 2.3kW of single burner are studied. The results show that the flame can achieve stable combustion within the set hydrogen blending range and heat load conditions except the condition of hydrogen ratio of 40% and heat load of 2.3kW. With the increase of hydrogen blending ratio, the internal flame height first increases and then decreases, the burner temperature first decreases and then increases, the emission of CO in flue gas gradually decreases, while the emission of NOx first has no obvious change but then gradually decreases