Research On Failure And Abnormal Vibration Of Tower Boiler Water Wall In A Thermal Power Plant 660MW Unit

The supercritical unit has the dual benefits of energy saving and environmental protection,and is a realistic and feasible choice for greatly reducing resource consumption.In recent years,tower boilers have been increasingly used by their own performance advantages.However,some tower boilers gradually appeared in the actual operation process of water wall leakage,boiler vibration and other problems,and there were safety hazards,which seriously affected the safe operation of the tower boiler unit.Therefore,the research on the stress status of the water wall and the tower research on furnace vibration is necessary.At present,there are relatively few researches on tower boiler water wall cracks and furnace wall vibration.This paper mainly studies a 660 MW tower boiler.Aiming at the crack failure phenomenon of the boiler’s water wall,the stress analysis of its water wall failure is carried out with the help of Ansys Workbench 19.0 software.Aiming at the abnormal vibration phenomenon of the boiler wall,through Fluent 2020 R2 software performs numerical simulation analysis on the combustion status in the furnace,and explores the relationship between the boiler vibration and the combustion status in the furnace.Aiming at the crack phenomenon of the water wall,a simplified three-dimensional model of the failure area was established.The boundary conditions were determined by calculation,and the water wall was solved by numerical simulation to obtain the stress distribution or temperature and thermal stress distribution of different models.According to the calculation results,the reason for the cracks is the unreasonable structural design,which will cause stress concentration in the water wall.The structure of the cracked part was optimized,and the optimized result was obtained by recalculation,which has an ideal optimization effect compared with the original model.In view of the boiler vibration problem,the characteristics of vibration were analyzed through field investigation and vibration test,and it was found that the vibration was mainly shock and irregular to follow.This phenomenon has a lot to do with the instability of boiler combustion.Perform three-dimensional modeling of the boiler as a whole,determine the boundary conditions,mesh the model,to obtain various parameter distributions of the combustion status in the furnace under different working conditions,such as temperature distribution,CO concentration distribution and velocity vector distribution.Finally,suggestions for the next step of work are put forward for the problems in the simulation calculation.