Lacing hole structure of turbine blade and loose lacing wire installation structure of the same turbine blade

Abstract

The utility model discloses a lacing hole structure of turbine blades and a loose lacing wire installation structure of the same turbine blades. The lacing hole structure of turbine blades comprises a straight circular boss structure, the straight circular boss structure is disposed on the turbine blades, the axis of the straight circular boss structure is perpendicular to the normal of the blade-shaped cross section of the turbine blades and is tangentially parallel to the impeller, a pressure side and a suction side of the blades protrude from the straight circular boss structure, a lacing hole is formed in the middle of the straight circular boss structure, the axis of the lacing hole and the axis of the straight circular boss structure are in the same direction, two small boss structures are arranged at the two ends of the lacing hole, the two ends are on one side of the lacing hole near to the top of the blades, and pits are formed on the side of the lacing hole near to the top of the blades. The loose lacing wire and the lacing hole have two contact points, thereby effectively improving the damping capacity of the loose lacing wire structure, shorting the free segment length of the loose lacing wire, reducing the stress level of the loose lacing wire structure, enabling the loose lacing wire to use alloy steels with good damping effect to replace titanium alloys, and being capable of controlling the stress level of the loose lacing wire structure and improving the damping capacity of the loose lacing wire structure at the same time.

Description

technical field [0001] The invention relates to the technical field of turbomachinery, in particular to a steam turbine blade loose tie reinforcement installation structure. Background technique [0002] The blade is responsible for the important task of converting steam heat energy into mechanical energy in the steam turbine. It is one of the most important components in the steam turbine. The blade is mainly composed of the blade root, the blade body and the blade crown, and some blades also have a lacing structure. [0003] During the operation of the steam turbine, the vibration stress generated by the blades on the rotor under the action of the pulsating gas flow is the main cause of its high cycle fatigue failure. Loose tie structure is often used in the structural design of blades to increase damping, improve dynamic strength and reduce dynamic stress levels, thereby improving the safety and reliability of blade operation. [0004] Such as figure 1 Shown is a three-...

AI Technical Summary

Problems solved by technology

On the one hand, due to the large pitch of the blades in the conventional loose tie structure, titanium alloys and other metals with low density are often used to reduce the stress concentration caused by the centrifugal force of the loose tie bars to ensure the strength requirements of the blade tie holes, but the titanium alloy The elastic modulus is lower than that of alloy steel, and its ability to suppress the vibration and deformation of the blade is lower than that of alloy steel

At the same time, due to the low density of titanium alloy, the centrifugal force is also small under the same conditions, so the damping effect is worse than that of alloy steel; Axial vibration and tangential vibration, but the effect of suppressing the torsional vibration of the blade is not good, and due to the large span of loose ties between adjacent blades, the stress at the contact point of the ties hole caused by centrifugal force is relatively large

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