Numerical Simulation And Optimization Research On Thermal Stress Of Special Shaped Tuyere Brick Of Supercharged Boiler

Supercharged boiler supplies air by turbo unit,fuel combusts in the furnace under the condition of pressure boost,supercharged boiler has high furnace volume heat load,small volume and many other advantages,but brings some disadvantages such as high temperature in the furnace,and the furnace flue gas scouring the refractory brick intensely,supercharged boiler furnace temperature can be as high as 1700?.The refractory brick makes up the furnace wall,and the refractory brick bears the high temperature scouring and heat radiation directly.Tuyere shaped brick is also affected by the combustion of air,and the working environment is more severe,damages the refractory brick easily by thermal stress.Once damaged,it not only increases maintenance costs,but also seriously affects the availability of equipment.Therefore,how to reduce the stress and improve the service life of the special shaped brick is very important of the boiler.In this paper,taking the supercharged boiler furnace wall brick as the research object,through the modeling and simulation of SIC special shaped tuyere brick,its characteristics can be obtained.Then we explore its influencing factors,and research how to reduce the thermal stress with the influence of various geometric parameters,the convective heat transfer coefficient,and the coefficient of expansion of refractory brick by the temperature field and stress field distribution..From the thermodynamic point of view,using the principle of heat transfer and finite element method,establishing the supercharged boiler refractory brick 3D model based on ANSYS parametric modeling method,we can determine the boundary conditions,the finite element analysis of the furnace wall grasps the change rule of supercharged boiler temperature field and stress field,and we can forecast the development and change of thermal stress.According to the theoretical analysis and simulation results we can obtain the following conclusions: with the increase of air convection heat transfer coefficient,refractory brick thermal stress gradually increases;with the increase of expansion coefficient,thermal stress increases gradually;the geometric parameters of refractory bricks also affect the distribution of thermal stress.Based on the above conclusions,the optimization scheme is put forward,it is of great significance to reduce the fracture of refractory bricks.