Analysis Of Heat Transfer And Flow In Regenerator Of Top-Combustion Hot Blast Furnace

On the basis of improving the shortcomings of non-uniform flow field inside the internal combustion hot stove and large area occupied by the external combustion hot stove,the top-combustion hot stove has improved its structural stability and more uniform air distribution,which has created conditions for achieving high air temperature and gained extensive attention in the iron-making industry.Regenerator is the most important part of top-combustion hot blast stove.Both heat absorption and heat release processes are carried out in regenerator.The heat transfer efficiency of heat absorption and heat release is directly affected by the structure of regenerator.Therefore it is particularly important to study the regenerator structure of hot blast stove.In this paper,the simplified model of 2500m3 hot blast stove is established.Two other physical models with different height-diameter ratio are obtained by changing the height of the regenerator.The combustion model,turbulence model and radiation model are set up by CFX.Firstly,the law of flue gas flow and heat transfer in regenerator of top-combustion hot blast stove during combustion period is obtained.Secondly,after the combustion period of top-combustion hot stove is over,the analysis of fluid flow and heat transfer process in regenerator during the supply period is started.Finally,the influence of changing the ratio of height to diameter of regenerator on the distribution of temperature field,velocity field,flue gas concentration field during the combustion period and temperature field,velocity field during supply period is analyzed.The simulation results show that:(1)The simulation results of flue gas flow and heat transfer of the traditional model are obtained,and compared with the previous results to verify the reliability of the analysis.(2)The comparative analysis of the temperature field in the regenerator of top-combustion hot stove shows that the temperature field distribution in the air supply period is more uniform than that in the combustion period;the temperature field of the second type hot stove is more uniform than that of the traditional model and the fourth-type hot stove,especially reflected in the reduction of the temperature difference in the high-temperature zone.(3)By comparing and analyzing the concentration field of flue gas in the regenerator of top-combustion hot blast stove,we can use the standard deviation method to compare the proportion of standard deviation of different models.The distribution of the concentration field of CO2 in the fourth type hot blast stove is better than the other two models,especially in the middle and lower part of the regenerator.(4)By comparing and analyzing the heat transfer efficiency of regenerator of top combustion hot stove,it can be concluded that the heat transfer efficiency of second type hot stove is obviously improved while meeting the requirements of operation;The heat storage capacity of the traditional model is larger than that of the other two models.