Abstract: Aiming at the high-temperature steam leakage problem of the steam turbine used by a large coal chemical enterprise, the front steam seal of steam turbine was reformed, based on honeycomb sealing technology, the structure design, simulation analysis and application of the steam turbine front seal were carried out. Based on the original labyrinth seal structure, the honeycomb seal structure was designed; the sealing flow field was simulated and analyzed by CFD software, and the difference in sealing performance between labyrinth seal and honeycomb seal was studied; the influence of labyrinth structure, honeycomb core lattice depth and core lattice diameter on the sealing performance of the honeycomb seal was studied. Finally, the front steam seal of the steam turbine was modified by processing new honeycomb seals to verify the sealing performance of the honeycomb seal. The research results show that the honeycomb seal with reasonable structure can effectively reduce the high-temperature steam leakage of the steam turbine; the honeycomb seal with labyrinth structure on the toothed rotor structure has better sealing performance; the deeper the depth of honeycomb core is, the smaller the diameter of honeycomb core is, and the better the sealing performance of honeycomb seal is; after the honeycomb seal modification, the temperature of the radial bush of the steam turbine is reduced by 20 ℃, the vibration is reduced by 45%; and the operating efficiency, safety and stability of the unit are improved.

Key words:  labyrinth seal; honeycomb seal; leakage rate;computational fluid dynamics(CFD);analysis of seal flow field