Turbine moving blade with bevelled prism cavities formed in blade top

Abstract

The invention provides a turbine moving blade with bevelled prism cavities formed in a blade top. The turbine moving blade comprises a blade body, the multiple bevelled prism-shaped cavities are formed in the blade top of the blade body from the front edge to the tail edge, the bottom faces of the prism-shaped cavities adopt a bevelled mode, the ratio of the maximum height of the prism-shaped cavities to the height of the blade body is 0.5%-4%, and the beveled angles for beveling the bottom faces of the prism-shaped cavities are within the range of 30-60 degrees. According to the turbine moving blade with the bevelled prism cavities formed in the blade top, a part of leakage fluid entering a gap enters the prism-shaped cavities to be curled up to form vortexes, on the one hand, kinetic energy of the gap fluid is dissipated, on the other hand, the jet blocking effect on the gap fluid above the cavities is formed, then the purpose of controlling blade tip leakage flow of a turbine is achieved, the bottom faces of the prism cavities are beveled, the vortex intensity and development direction of the vortexes in the cavities are changed, the mixing effect of the fluid flowing into / flowing out of the cavities and the fluid in the gaps on the upper portion is enhanced, inhibiting turbine blade tip leakage flow is more advantageous, and the structure is simple.

Description

technical field [0001] The invention belongs to the technical field of turbines, and in particular relates to a turbine moving blade with a chamfered prismatic cavity provided on the top of the blade. Background technique [0002] There must be a certain tip clearance between the rotating blades and the casing inside the turbine. Due to the existence of the tip clearance, the tip clearance leakage flow must be formed under the action of the lateral pressure gradient on both sides of the blade pressure surface and suction surface. On the one hand, separation flow will be generated inside the gap due to wall shearing; on the other hand, the leakage flow out of the gap forms a leakage vortex on the suction side, which is mixed with the mainstream fluid such as the upper channel vortex and blade radial fluid, and finally leads to the flow in the blade end region. Complicated, the cascade loss increases, which has a great impact on the efficiency and overall performance of the tu...

AI Technical Summary

Problems solved by technology

On the one hand, separation flow will be generated inside the gap due to wall shearing; on the other hand, the leakage flow out of the gap forms a leakage vortex on the suction side, which is mixed with the mainstream fluid such as the upper channel vortex and blade radial fluid, and finally leads to the flow in the blade end region. Complicated, the cascade loss increases, which has a great impact on the efficiency and overall performance of the turbine

Especially in recent years, with the increase of turbine load, the lateral pressure gradient increases, which makes the leakage flow intensified and the cascade loss further increases

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