Study On The Combustion And Vibration Characteristic Of Hoogovens Internal Hot Blast Stoves

With the improvement of blast furnace smelting strength,enhanced combustion of hot air stove,due to the design of hot blast stove when not considering the demand enhanced combustion,so the vibration problems in strengthening smelting blast furnace hot blast stove.Of blast vibration research at home and abroad is less,the burning of the gas movement within the hot blast stove,and the relations between vibration is not clear,so it is necessary to study gas flow movement in the hot blast stove,combustion process and the vibration characteristic,provide theoretical support for hot blast stove design and operation.In this paper,the vibration characteristics of the hot blast furnace in a steel mill are studied.Through CFD simulation,the gas flow and combustion process of combustion chamber are analyzed.The transient calculation of the pressure and temperature fluctuation in the combustion chamber is analyzed by FFT,and the spectrum of temperature and pressure fluctuation in the combustion chamber is discussed,and the vibration characteristics of the hot air furnace are compared and analyzed.On the basis of this study,the influence of air nozzle,air nozzle Angle and air flow distribution on combustion and vibration is studied.Through the research,the relationship between the gas movement,combustion process and the vibration of hot blast furnace in the combustion chamber of the hot air furnace is basically found,and the main conclusions are as follows:(1)The vibration test of the field shows that the vibration of hot air furnace is mainly caused by combustion.The maximum amplitude of vibration of the furnace and platform is within 20 Hz.(2)At the bottom of the combustion chamber near the wall,there is a low-speed backflow area,which promotes the mixing of air and gas and is conducive to the stability of the flame.The height of air ring road determines the uniformity of velocity in the ring road and the distribution of velocity distribution of nozzle outlet.(3)Along the height of each section in the combustion chamber of the temperature distribution are similar,but in a larger temperature difference along the height direction,which exists in different heights section of combustion chamber CO,shows that the combustion of the combustion chamber is not sufficient,the quality of the export section in CO percentage is 2.5%,so the burner combustion efficiency is low.(4)Pressure fluctuations peak corresponds to the frequency concentrated between 10 to 15 hz,peak frequency and the measured vibration frequency of blast furnace pressure fluctuation,pressure fluctuation in the combustion chamber combustion process is induced vibration of the main causes of blast furnace.(5)The influence of heat blast furnace load,gas nozzle,air nozzle Angle and air flow distribution on both sides of air is not obvious to the combustion process,but the fluctuation amplitude of pressure is greater.Increasing the load of the hot blast furnace and reducing the size of the gas nozzle will increase the fluctuation amplitude of the pressure.With the increase of Angle alpha,pressure fluctuation amplitude increase,when the Angle of alpha = 60 ° the peak amplitude of alpha = 55 ° 10 times;The distribution of air flow on both sides is not uniform,and the amplitude of pressure fluctuation is greater.