Research On Sealing Performance Of Thick Wall Honeycomb Seal And Hole Pattern Seal And Study On Suppressing Blade Bivration With Suction Method

Working Parameters of turbomachineries become higher and higher, such as medium pressure and flow. It results in higher performance for seal and stability. Honeycomb seal has excellent performances both on sealing and rotor dynamic damping. However, complicated machining process, special material and high application cost are the shorTomings of honeycomb seal. Thick wall aluminum honeycomb seal and hole pattern seal can realize overall manufacturing easily. They can also offer more safe work conditions. So they have new advantages compared to traditional honeycomb seal. Blade vibration is another important problem in turbomachineries, also a difficulty, and there are few effective methods to suppressing blade vibration in engineering field. To solve these problems, this paper has finished the following tasks:1) Three dimension whole models of honeycomb seals and hole pattern seals were constructed. Sealing performance of the two kinds seal structure was study with numerical method. Structure parameters influence the leakage rate directly, and the influence mechanism was analyzed from two perspectives, gas backsurging effect and vortex structure. Then, the sealing advantage between honeycomb seal and hole pattern seal was compared. Result showed that depth of honeycomb seal or hole pattern seal influenced gas backsurging effect and vortex structure obviously. The stronger the gas backsurging effects, the more obvious low speed domain formed in the clearance, and the less gas leakage. When the honeycomb opposite edges distance or hole diameter was 3.2mm, wall thickness was 0.8mm, the optimum depth for the two seal structure was 0.8mm. When the depth was 3.2mm, honeycomb opposite edges distance or hole diameter influenced the leakage rate a little. However, when the depth was 0.8mm, leakage rate decreased as the opposite edges distance or hole diameter increasing under 3.2mm. When the parameter was bigger than 3.2mm, leakage rate was trending towards stability. Leakage rate increased as the wall thickness increasing, but when wall thickness was in the range of 0.4mm-1.0mm, leakage rate increased a little. Comparing the leakage rate of thick wall honeycomb seal and hole pattern seal, their sealing performances showed a little difference on the whole, and that which one was better was depending on the structure parameters.2) Several technological transformation projects were completed for steam turbines and axial compressor with honeycomb seal technology. Problems such as seal leakage, lubricant oil deteriorated by water, rotary blades flushed by water drops were solved effectively. These problems had disturbed the petrochemical and electric power corporations for a long time. The available transformation effects showed that honeycomb seal can improve the performances for turbomachineries.3) Experiment investigation of suppressing blade vibration with suction method was finished, and influence to flow field around blade from suction was analyzed by numerical simulation. Results showed that traces of suction flow can suppress blade vibration effectively.