Numerical Simulation And Research Of High Temperature Air Combustion Technology

High temperature air combustion technology is an important energy-saving and green combustion technology. This paper firstly discussed the HTAC technology about its development, basic principle, characteristics, key technology and its application prospect in our country, and then studied this new combustion technology by lots of numerically modeling experiment. The variation rule of temperature distribution and NOx emission in industry furnace with different pre-heated temperature of air or different oxygen concentration was illustrated.In this paper, the standard k-εmodel which has been widely used in industry flow was used to simulate the turbulent flow. And, the standard wall function was used in the wall-adjacent zone, which should ensure the consistent of computational result and the practical flow for the precision. The P-1 model and the WSGGM model were used to calculate the radiation heat transfer and the absorption coefficient of combustion gases. The mixture fraction/PDF model was used to simulate the combustion process because the fuel and oxidizer enter into the burner by different channel. The Zeldovich's thermal NO calculation model was employed to calculate the emission concentration of NO in the combustion process.According to the numerically simulation results, when the combustion air preheated temperature increased from 300K to 1300K, the maximum temperature, the mean temperature and the temperature deflection in the furnace were linearly increased, while the molar concentration of NO increased exponentially, a total increase of 5 orders of magnitude; when the oxygen concentration of the combustion-supporting air was diluted from 21% to 7%, the maximum temperature and the temperature deflection in the furnace linearly decreased, and the emission concentration of NO also exponentially reduced. HTAC technology has great advantages compared with conventional combustion, because of the fuel was burned at high temperature and low oxygen concentration. Thus, it doesn't only help to improve the efficiency of heat exchange in the furnace which will reduce the fuel consumption, but also to reduce the NOx emission.