Numerical And Experimental Study On Combustion Characteristics Of Metal Fiber Ultra-Low NO_x Burner

Metal fiber surface burners are a new type of porous media combustor.Compared with the traditional diffusion gas burner,it has the advantages of low NOx emission,high combustion intensity,good anti-tempering performance and so on.In addition,the metal fiber surface burner owns compact structure,high combustion efficiency and low exhausted flue loss,which obeys China's basic national policy of energy saving and environmental protection.Based on the metal fiber combustion technology,this paper studies the flow and combustion simulation with commercial software,and draws the corresponding results and conclusions.At the same time,the test bench is developed to explore the combustion state and the emission of NOx under different working conditions.First of all,the structure,principle and characteristics of metal fiber surface burner were described.Then the developed metal fiber surface burner test bench was introduced.Its specific system configuration and control logic are described in detail.Secondly,the numerical simulation of the cold flow field in the combustor was carried out,and the gas-air mixed flow conditions with the different mixing components were studied.The results show the built-in impeller and orifice plate can effectively improve the mixing degree of gas and air.Then,the cold test and hot experimental study of the test bench were conducted.The flow conditions in cold condition verify the correctness of the simulation results.The concentration of emission of the test bench under each combustion condition was measured.The experimental results show that the test bench can complete combustion under several conditions with ultra-low nitrogen emissions,which has met the performance requirements.Finally,the structure optimization of the metal fiber arrangement under specific operating conditions was carried out.The influence of different arrangement methods of fiber on the velocity distribution,the temperature distribution and the concentration distribution of the components in the model area was obtained.The best simulation result is obtained under the condition of double-row variable-diameter metal fiber.