Study On The Application Of Honeycomb Seal Technology In Steam Turbine For Refining Unit

Steam turbine is a kind of rotating machine which is used to convert steam energy into mechanical work.It is a key machine of modern oil refining unit.At present,comb labyrinth seal has been used widely in most of these steam turbines,in which shaft end seal leakage problem has existed widely.Leakage not only causes loss of high temperature and high pressure steam,reducing the unit efficiency,and steam channeling to bearing box may cause oil emulsification,seriously endangering the safe operation of equipment,further burying hidden dangers to the safety of production enterprises.This article hopes to solve this difficult problem through the research on technical innovation of turbine shaft seal.The main work of this paper are summarized as follows:(1)By building a three-dimensional model of the honeycomb seal and hydrodynamic analysis model,using the fluid dynamics computational software FLUENT,sealing performance of honeycomb seal and its influence factors have been analyzed and calculated,and the best cellular structure size has been obtained.(2)The dynamics simulation analysis has been carried out on the honeycomb seal.The results show that the honeycomb seal not only has good seal performance,but also has good dynamic characteristics.Honeycomb seal can be used in a very small clearance seal without vibration problem of interstitial fluid,which improves the stability of the steam turbine rotor.Because the diaphragm is made from soft wear-resisting material,the honeycomb seal has the characteristics of wear resistance and no damage to the shaft.The honeycomb seal can effectively replace the traditional labyrinth seal.(3)The honeycomb seals have been designed and manufactured.Which have been used in shaft ends of D50-14 turbine in the 2nd catalytic unit.Technical innovation of shaft end seal of D50-14 turbine has been finished.Since June 2015,honeycomb seals have been put into use,the machines have been running smoothly and being excellent in sealing performance.The following conclusions can be obtained according to the research results of this thesis:it is feasible to reconstruct labyrinth seal with honeycomb seal and honeycomb seal can be used in the seal of steam turbine in refining units.