Study On Force Analysis Of Top Combustion Hot Blast Stove And Optimization Design Of Hot Blast Stove Checker Brick

Longevity,high efficiency,energy conservation and environmental protection are essential indicators for hot blast stove design.With the continuous development of large-scale blast furnace,as the hot blast supply equipment for blast furnace,the higher design blast temperature and higher working pressure of the hot blast stove has brought more potential risk and various safety problems may happen.It is necessary to study the stress and deformation of the hot blast stove and the structural optimization of checker brick.In this paper,aiming at the insufficiencies of previous studies and the actual hot blast stove damaged,the stress and deformation of two typical kinds of currently used hot blast stove body,hot blast main and manifold shell,furnace refractory lining are studied in detail.Through the analysis of the stress,strain and displacement component,the mechanism of deformation is investigated and the theoretical foundation for the design and operation of hot blast stove with lower stress and deformation has been laid.In addition,the factors that influence the heat transfer of the regenerative chamber are studied.The above researches lay a solid theoretical foundation for the longevity and efficient design,operation and maintenance of the hot blast stove.(1)The thermal elastic-plastic stress and strain mathematical model of two typical top combustion hot blast stoves and pipe shell contained pre-combustion chambers,combustion chambers,regenerator chambers,the hot blast manifold,the hot blast main,hot blast valve,draw bar,corrugated compensator are established.Through the comparison between the calculation results and actual measured data in the field,the accuracy and reliability of the established mathematical models are verified.(2)Based on the numerical simulation of A Type hot blast stove and piping system,the stress and displacement distributions of the stove body,hot blast main and manifold shell are calculated.Under the force of the blind plate,the hot blast stove shell and the hot blast main have different degrees of elongation and bending deformation,causing the deformation of the both ends of the hot blast manifold and different degrees of stress concentration.Plastic strain may occur in the upper and lower part of the hot air outlet.(3)The repeated deformation of the steel shell of the hot blast stove during the cycle of combustion and blast period are investigated.A Type blast stove body shellmay rise and fall,be closed to and far away from the hot blast main,hot blast manifold may elongate and shorten,hot blast main may be close to or far away from the stove body,repeatedly.Each manifold compensator may elongate or shorten repeatedly,as the length change of main compensator is very small.(4)The numerical simulation analysis of B Type hot blast stove and pipeline system with four stoves is performed and compared with the A Type hot blast stove.The influence of different piping distributions,operating systems,design and operation parameters on the force and deformation of the shell is studied.Force distribution of B Type hot blast stove shell is similar to that of A Type hot blast stove,but there are differences in the deformation of pipeline.During the cycle of combustion and blast period,the hot blast main is kept near the central axis of the main line as the 4 B Type stoves are located at both sides of the main line.The hot blast main has a clear tendency to be away from the hot blast stove as the A Type stores are located at the same side of the main pipe.In addition,the position change of hot blast main in B Type hot blast stove of ipsilateral alternating state is smaller than that of relative alternating state,but the length change of compensator is larger.(5)A thermal elastic-plastic stress and strain mathematical model of B Type top combustion hot blast stove lining is established.Stress and deformation of refractory materials under high temperature and refractory brick gravity are investigated.By combining the deformation of hot blast stove lining and shell,the interaction between the lining and stove shell is analysis.According to the lining deformation under different load conditions,there are two damage probability areas in the hot blast stove lining.At the upper part of hot blast outlet,the refractory is under tension stress and elongated along the circumference direction,and the lining is easy to loosen.At the lower part of the conical part of the combustion chamber,the external extended of lining is most obvious and the refractory is under tension stress and elongated along the circumference direction,the lining is likely to loosen.This conclusion is consistent with the actual hot blast stove damaged.(6)A two-dimensional heat transfer mathematical model of checker brick in the regenerator is established.The computing method of optimal mixing volume is proposed and the optimal mixing volume is obtained.With the increase of living area,the blast temperature rises,and when the living area exceeds the critical value,the high-temperature area expands downward,the blast temperature drops faster,the optimal mixing volume is increased,and the wind temperature decreases.With the decrease of the brick hole diameter,the specific heat,the ratio between total flue and blast,the CO concentration,preheating temperature,excess air coefficient,or the increases of thermal conductivity,the optimal living area is reduced.In addition,with the increase of excess air coefficient,the maximum blast temperature first increases,then decreases,and there is a most suitable excess air coefficient.