Influence Of Cooling Mode And Flow Structure Of Gasification Burner On Combustion And Heat Transfer

The burner is the core equipment in the production of non-catalytic partial oxidation of natural gas.The cooling mode and flow structure of the burner are the key parameters affecting the service life of the burner and the methane conversion efficiency.In this paper,the heating conditions of the burner of the natural gas non-catalytic partial oxidation converter under different cooling modes and the thermal stress of the burner end face are studied by means of numerical simulation,which provides a theoretical basis for the design of steam-cooling mode applied to the burner.The natural gas non catalytic partial oxidation gasifier is selected as the research object,and the numerical simulation of non-catalytic partial oxidation of natural gas is carried out using Fluent software when the traditional cooling water jacketed burner is used.The simulation value of the wall temperature of the reformer is consistent with the experimental results.A steam-cooled three-channel burner model with steam as the cooling medium was established.The steam-cooled three-channel burner and the water-cooled dual-channel burner were analyzed by numerical simulation,and the effects of the two cooling methods on the burner end face were investigated.The results show that the temperature at the outlet of the reformer decreases with the increase of steam volume after steam is introduced into the reformer by steam cooling;the steam delays the temperature rise of spontaneous combustion reaction and reduces the reformer temperature.The maximum temperature of the reformer using the steam-cooled three-channel burner can be about 300 K lower than the maximum temperature of the water-cooled dual-channel burner;increasing the steam velocity can significantly reduce the maximum temperature of the end face;under the two cooling modes,the maximum temperature of the end face of the burner is located in the middle of the outer end face of the burner;when the steam flow rate is 80 m/s,the maximum thermal stress of the steam-cooled three-channel burner is equivalent to that of the water-cooled dual-channel burner.On the basis of steam-cooled three-channel burner,the effects of different burner channel structure,O2/CH4 volume ratio,steam flow rate and natural gas preheating temperature on burner combustion were investigated.The results show that when the steam channel is used as the middle channel and the outer channel respectively,the total heat transfer on the burner end face is basically the same;the increase of O2/CH4 volume ratio can promote the combustion reaction in the reformer,and the maximum temperature near the burner end face also increases,which will lead to the decrease of H2 and CO content in the generated syngas;the increase of steam flow rate has a great effect on reducing the maximum temperature,average temperature in the reformer and the temperature at the outlet,but has no obvious effect on the syngas generation;the higher the preheating temperature of natural gas,the lower the CH4 content at the outlet.