Thermal Fluid Solid Coupling Analysis And Optimization Of Twin Screw Extruder Barrel

As the main component of the extruder,the twin screw extruder barrel is the important guarantee for the screw to rotate and process the material in its internal rotation.It is the main operating device for the precision control of the temperature in the process of the extrusion.Generally,the extruder cylinder should be used in the coupling field with complex thermal environment and variable force,and the gap between the cylinder and the screw should be limited in a certain range.Therefore,the structural strength and stiffness should meet certain requirements.At present,the design and optimization of the barrel structure mostly depends on the experience of the technicians and the method of experimental verification.However,with the improvement of the industrial application standards,the idea of the optimization design can not meet the needs of the people.So we need to use the computer technology to make numerical simulation to realize the design and optimization of the barrel structure.In this paper,a new numerical simulation analysis method for the twin screw extruder barrel is developed.On this basis,topology optimization is used to optimize the structure of the cylinder,and the optimal structure of the barrel is obtained.A simplified calculation model is established based on the gravity heat pipe barrel structure,and the structure is analyzed by indirect thermal fluid solid coupling numerical simulation method.After calculating and analyzing the pressure distribution,temperature distribution and the characteristics under different operating conditions of fluid,the results are transferred to the solid structure for structural performance analysis.The simulation results of the solid structure show that the thermal load plays a major role in the deformation of the barrel,and the force load has the main influence on the equivalent stress of the barrel.The deformation of the barrel and the distribution of the equivalent stress obtained by the coupling load are more in line with the actual situation.The maximum deformation position of the barrel under the coupling load is at the end of the flange,and the maximum equivalent stress appears at the abrupt position of the structure connecting the flange to the inner and outer walls.Through the study of the structure performance of the barrel under different operating conditions,the maximum deformation of the barrel under the coupling load increases with the increase of the temperature(thermal load),but the change of the pressure is very small.With the increase of temperature and pressure,the maximum deformation difference of the barrel increases with the coupling and uncoupled loads,and the effect of coupling load is becoming stronger and stronger.The maximum equivalent stress value of the barrel increases with the increase of the temperature and pressure.When the temperature load increases,the smaller the pressure value is,the faster the maximum equivalent stress value increases.When the pressure load increases,the lower the temperature is,the faster the maximum equivalent stress value increases.Finally,the topology optimization of the gravity heat pipe cylinder is designed.After the topology optimization of the cylinder,the weight of the single cylinder body is reduced by 4.04 Kg.Although the total structure deformation amount has a small increase,it can be seen as basically no change.The maximum equivalent stress value of the structure is reduced by about 23%,and the safety factor of the cylinder is large.The improvement of the structure has reached the desired goal.