Numerical Simulation And Experimental Research On The Combustion Characteristics Of Swirling Gas Stoves Mixed With Hydrogen

As an important part of the future national energy system,hydrogen energy is an important carrier for realizing the transformation of energy to green and low-carbon.As a clean energy with zero pollution and high calorific value,hydrogen can be produced through renewable energy.Many countries today incorporate hydrogen into natural gas pipelines for transportation applications as fuel for end-users.Among the existing end-user burning appliances,gas stoves are necessities of people’s lives,and harmful gas pollutants will inevitably be generated during use.The mixing of hydrogen can effectively reduce gas pollutants and carbon emissions.Most of the current gas stoves are designed based on natural gas as fuel,and there are few researches on the application of natural gas mixed with hydrogen in household gas equipment.In order to better study the application of natural gas hydrogen-mixed combustion technology in household gas stoves,this paper takes the commonly used swirling gas stove as the research object,and at the same time analyzes the combustion kinetics of methane hydrogen-mixed fuel.The detailed mechanism of the cyclone gas stove was simplified,and the simplified mechanism was verified by numerical simulation and thermal experiments.Then,the simplified mechanism was used to carry out the numerical calculation and result analysis of the hydrogen-mixed combustion of the swirling gas stove.The specific research contents and conclusions are as follows:（1）First,a numerical model of a one-dimensional premixed laminar flame was established based on the GRI-Mech 3.0 mechanism,and the effect of different hydrogen doping ratios on the combustion of the premixed flame was studied.It was found that the addition of hydrogen promoted the low-temperature reaction of methane combustion and improved the The combustion efficiency is improved,the yield of free radicals OH and H is increased,the overall reaction rate of combustion is promoted,and the NO₂ emission factor is reduced.The combustion speed of laminar flame increases with the increase of hydrogen admixture ratio,and the effect is greater in rich fuel conditions.（2）Secondly,the key components of the methane combustion process were obtained by sensitivity analysis,and then the reduced mechanism of the 17 components and the 58-step reaction was reduced by using the directed relation graph method.Compared with the detailed mechanism of GRI-Mech 3.0,the components and chemical reactions are greatly reduced.（3）Finally,the numerical simulation calculation was carried out on the ejector of the swirl gas stove.The results showed that when the hydrogen mixing ratio was 5%,10%,and15%,the primary air coefficient increased from 0.705 to 0.715,0.727,0.74,and based on this result,the hydrogen mixing simulation of the swirl gas stove was carried out.The results show that when the volume fraction of hydrogen doped is 5%hydrogen,the combustion temperature decreases by 6.6%.When the hydrogen ratio is 10%and 15%,the temperature fluctuation range is only±10K.In terms of pollutant emissions,when the hydrogen doping volume fraction is 5%,the CO molar volume fraction decreases by 9%,and when the hydrogen doping volume fraction is 10%and 15%,the CO molar concentration decreases by 8%and 8.1%.The mixed combustion of hydrogen ensures a certain combustion temperature,and the CO emission generally maintains a downward trend.The NO in the simulation calculation is mainly generated by a thermodynamic mechanism,the concentration of NO_X generally showed a downward trend.