High-pressure main steam combined valve capable of locally reducing stress and stress analysis method

Abstract

The invention discloses a high-pressure main steam combined valve capable of locally reducing stress and a stress analysis method. The combined valve comprises a valve body (1), the valve body (1) is provided with at least one valve front drain hole (11), and the valve front drain hole (11) is connected with the valve body (1) through a transition round edge (12); the valve body (1) is of an integrally-formed structure, the valve body (1) comprises a regulating valve body (2) and a main steam valve body (3) communicating with the regulating valve body, a steam inlet pipe (21) and a steam outlet pipe (31) are fixed to the side face of the regulating valve body (2) and the side face of the main steam valve body (3) respectively, and the valve front drain hole (11) is formed in the side face wall of the regulating valve body (2); and a valve back drain hole (13) is formed in the side face wall of the main steam valve body (3), and at least one door rod steam leakage drain hole (14) is further formed in the valve body (1). The combined valve and the stress analysis method have the advantage that local stress concentration of the valve body drain hole can be reduced.

Description

technical field [0001] The invention relates to the field of power station valves, in particular to a high-pressure main steam combined valve with locally reduced stress and a stress analysis method. Background technique [0002] Steam turbine is the main equipment of modern thermal power plants. The high-pressure main steam combined valve is an important component of the steam turbine. Once the valve has stress concentration and cracks, it will affect the economic benefits of the power plant and may bring serious safety hazards. [0003] The steam turbine of a power plant adopts the D10 standard steam turbine produced by GE Company. After a long period of operation, the high-pressure main steam joint valve of the steam turbine has serious cracks at the position of the drain hole (such as Figure 3 to Figure 5 As shown), after analysis, the unreasonable design of the drain hole structure of the high-pressure main steam combined valve is an important cause of stress concentrat...

AI Technical Summary

Problems solved by technology

After the soft nitriding treatment, the utility model eliminates the local stress concentration on the inner surface of the high-pressure chamber of the valve box, does not cause local damage due to stress concentration, improves the hardness of the inner surface and maintains the strength and toughness so that it can resist erosion and abrasion. Under the action of alternating load, it is not easy to produce cracks. The nitrocarburized layer can improve the corrosion resistance of the inner surface, which is suitable for acid fracturing or fracturing with corrosive fracturing fluid, and improves the overall strength of the valve box. Extend the service life, reduce production costs, reduce safety hazards in processing, simple process, and strong practicability, but this patent cannot prevent the appearance of cracks around the hydrophobic holes

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