Research On The Effect Of Partial Premixed Combustion Characteristics Of Natural Gas Mixed With The Hydrogen

Hydrogen and methane,as high-calorific-value-flue,and low-pollution clean energy,can effectively alleviate the increasingly serious environmental pollution problems and have great development prospects in the field of electric power generation.With the rapid development of heavy-duty gas turbines,socio-economic progress has been steadily progressing,but it also causes serious pollution emission problem.This dissertation uses numerical simulation to increase the volume of hydrogen during the combustion of methane while maintaining the power of the gas turbine,and study the influence of the volume of hydrogen on the methane combustion process,law of speed change,the combustion of fuel and the generation of combustion products.The main content and conclusions of this paper are as follows:First,by using GAMBIT software to model the combustion testbed in proportion,and the structural details are simplified.The meshing and quality verification of the test bench model,and the grid independence verification of different grid sizes,while considering the consumption of computer resources combined with the accuracy of the data results,114W grid model was selected for experimental simulation.Secondly,Fluent software was used to simulate the combustion testbed model.The temperature distribution during methane combustion,the characteristics of flame structure,the change of fuel during the combustion process,and the generation of pollutants were studied under the condition of hydrogen mixing rate change.The analysis focuses on the changes of temperature peak on the combustion chamber,the range of the high temperature region,the change in the length of the flame,the distribution characteristics of the axial velocity,the change in the area and content of CO2 and NO,and the change in the mass fraction of fuel combustion.The research results show that:With the increase of the mixing rate of hydrogen,the peak combustion temperature has an increasing trend,and the range of the high temperature region has narrowed;the flame length decreases with the increase of the hydrogen content,and the flame width slightly increases;the existence of the recirculation zone results in a negative velocity in the axial distribution;as the hydrogen content increases,the CO2 content decreases,and the mass fraction of NOx steady increases.Under the combination of temperature changes and product formation,when the blending rate is 20%,the temperature cloud map is well distributed,the CO2 mass fraction is significantly reduced,and at the same time,the peak value of the NO mass fraction is significantly lower than the peak value when the blending rate is 40%.The hydrogen blending rate is selected.20%as the best blending conditions.The analysis of the results shows that:As the equivalence ratio increases,the temperature peak increases,the high-temperature region extends in the axial and radial directions,the flame length becomes longer,and the change in CO2 is not large,but the NO content is significantly reduced.Properly increasing the equivalence ratio is beneficial to control the generation of NOx.