Stress Analysis And Optimization Design Of Key Components In Radiation And Convection Section Of Reforming Furnace

As one of the main heating equipment in refinery and petrochemical plant,the safety design of reforming furnace structure is particularly important considering the long-term operation of radiation chamber and convection chamber in high temperature special working environment.At present,the traditional design method of heating furnace mainly depends on the commonly used theory and empirical formula to determine the structural parameters,which leads to conservative design method,low efficiency and high cost.In recent years,the analysis and design method represented by the finite element method has more advantages in solving the structural design and analysis.Therefore,based on the finite element analysis,this paper will carry out the stress analysis and optimization design for the key components of the radiation and convection section of the reforming furnace.The specific research work is as follows:(1)Stress analysis and optimization design of U-shaped radiant coil.Taking the positive U-shaped radiant coil as the research object,the whole structure finite element model of radiant coil and the local substructure finite element model of hanger and cross are established.The results show that: through the stress analysis of the radiant coil structure,the stress of the radiant coil structure in the cold and hot conditions meet the strength conditions,but the stress of the structure in the hot condition is larger;through the optimization analysis of different spring hanger layout schemes,the load distribution of the hanger is better and the stress is safer after the optimization;through the safety margin analysis of the given spring hanger The safety margin decreases with the thinning of the base plate thickness,and the thickness of the base plate is optimized from 20 mm to 7mm;through the optimization analysis of the lightweight structure of the manifold,the mass of the manifold is changed from 8498 kg to6156kg,reducing by 27.6%.(2)Stress analysis and optimization design of inverted U-shaped radiant coil.Taking inverted U-shaped radiant coil as the research object,the whole structure finite element model of radiant coil and the local substructure finite element model of support and cross are established.The results show that: through the stress analysis of the radiant coil structure,the stress of the radiant coil structure under different working conditions of cold state and hot state meets the strength conditions,but the stress of the structure under the hot state is larger;through the optimization analysis of different support layout schemes,the load distribution of the support is better and the stress is safer after the optimization;through the optimization analysis of the manifold structure lightweight 9 kg to 1311.9 kg,a decrease of 26.3%.(3)Buckling analysis of inverted U-shaped radiant coil.Considering the slender structure of the inverted U-shaped radiant coil and the operating conditions of temperature,pressure and other processes,the structure is prone to buckling.Taking the overall structure of inverted U-shaped radiant coil as the research object,based on the original furnace tube temperature of600℃,furnace tube length of 9219 mm and furnace tube diameter of 89 mm,the buckling analysis of the structure is carried out by controlling a single variable The results show that the critical temperature of furnace tube is 789 ℃,the critical length of furnace tube is11723 mm,and the critical diameter of furnace tube is 76 mm.(4)Lightweight design of convection intermediate tubesheet.In this paper,a finite element model of the tube sheet is established to analyze the stress and deformation of the tube sheet structure,and the structure optimization is carried out in different order from the angle of rib thickness,rib width and tube sheet thickness.After optimization,the thickness of rib plate is reduced from 25 mm to 15 mm,the width of rib plate is reduced from 120 mm to119 mm,and the thickness of tube plate is reduced from 30 mm to 29 mm.After optimization,the mass of the convective intermediate tubesheet is reduced from 599.53 kg to 296.6kg,which is reduced by 50.5%.Through the stress analysis and optimization design of the key components of the radiation and convection section of the reforming furnace,the structural strength and performance are improved,which is of great significance for the engineers to determine the relevant design parameters reasonably.