Life Prediction Of The Coke Pushing Rod In Large Coke Oven Based On Thermal-mechanical Coupling

The coke pushing vehicle is an important mechanical equipment in coke production,and the coke pushing rod is an important component structure of the coke pushing vehicle,which is responsible for pushing the coke out of the carbonization room.Because the coke pushing rod is in a harse environment such as high temperature and heavy load,the temperature will change dratically after the pushing rod enters the carbonization room.In the process of pushing the coke,the pushing rod not only bears the mechanical load,but also bears the thermal stress caused by the temperature change.The repetitive cycle of the coke pushing process leads to continuous changes in the temperature and force of the coke pushing rod,which in turn causes deformation or fatigue damage under the coupling of temperature load and mechanical load,which seriously affects the use of the coke pushing vehicle,reduces the efficiency of pushing the coke and affect the economic benefits.Therefore,it is necessary to conduct thermal-mechanical coupling analysis and fatigue life prediction on the coke pushing rod.This subject is based on the key coal-based scientific and technological research project of Shanxi Province,"Large modern coke oven and equipment manufacturing technology research and development and engineering demonstration sub-project-push rod structure stability and vibration reduction technology research(project number: MJH2014-08)”,taking the coke puhing rod of 6.25 m large coke oven as the research object,the simulation boundary conditions are established through experiments and theoretical analysis.,the thermal and mechanical coupling analysis of the coke pushing rod in the process of coke pushing is carried out to analyze the deformation and stress distribution.Based on the simulation results,predicting the fatigue life of the coke pushing rod can provide a reference for the maintenance and protection of the coke pushing rod,and extend the service life of the coke pushing rod,which is of great significance for improving the economic efficiency of the enterprise.The main tasks are as follows(1)The structure and working principle of the pushing equipment areanalyzed.The method of experiment is used to extract the data of the pushing rod in the working state.According to the extracted pushing current and pushing frequency,the pushing speed is calculated,and an estimation method of pushing resistance based on the numerical change of pushing current is proposed to estimate the pushing resistance.According to the extracted acceleration data,the acceleration spectrum is simulated to obtain the load spectrum.(2)Based on the thermodynamics theory,the finite element equation of temperature field and the equilibrium finite element equation of structural deformation are established.Based on this,thermal-mechanical coupling finite element equation is established.Considering the characteristics of the coke pushing rod as a large component,the sequential coupling method is proposed to solve the thermal mechanical coupling problem of the pushing rod.(3)The thermal boundary conditions of the pushing rod in the process of pushing are determined.the transient temperature field of the pushing rod is calculated based on the determined thermal boundary conditions,the temperature change trend of the pushing rod and the temperature distribution of each load step are obtained,the indirect verification of the simulation results of the temperature field of the pushing rod is carried out in combination with the temperature test,which provides support for the thermal coupling analysis of the pushing rod.(4)On the basis of the obtained temperature field,the mechanical boundary conditions are applied to the pusher bar,and the comprehensive deformation and stress of the pusher bar under the thermal mechanical coupling are solved,compared with the deformation and stress of the pusher bar under the temperature load alone and the mechanical load alone,the thermal mechanical coupling characteristics of the pusher bar are analyzed and explained.(5)Based on the simulation results of the thermal-mechanical coupling of the pusher bar,the service life of the pusher bar is predicted,and the predicted results are compared with the relevant literature data to analyze the reasons for the differences in the results.Considering that there are many factors that affect the life of the pusher bar,this paper discusses the factors that affect the life of the pusher bar combined with the simulation results,andbriefly analyzes other potential factors.