A Repairing Method of Inlet and Outlet Header of High Temperature Superheater

Abstract

The invention discloses a high-temperature superheater access port header repair method, and belongs to the field of thermal power generation. The repair method comprises the following steps: (1) a fourth branch pipe is cut off from the root part of a header to the straight part of the branch pipe; (2) a welding base hole is formed in the header; (3) a connecting pipe is replaced; (4) the connecting pipe is welded between the header and the remainder part of the branch pipe; and (5) the welded part is online heated; and the heat treatment has the following parameters: the heat treatment adopts high-temperature tempering; the tempering temperature is 730+-10 DEG C; the temperature raising and lowering speed is 125 DEG C / h; the temperature keeping time is 210 minutes; in the cooling process, the temperature of below 300 DEG C cannot be controlled; and the whole process is automatically recorded through dotting. The repair method can overcome the defect of easy generation of welding line cracks due to generation of stress caused by insufficient curvature of the fourth branch pipe of a high-temperature superheater access port header, and guarantees normal work of the header.

Description

technical field [0001] The invention belongs to the field of thermal power generation equipment, and in particular relates to a method for repairing an inlet and outlet header of a high-temperature superheater of a steam boiler in a thermal power plant. Background technique [0002] In thermal power generation enterprises, relying on the combustion of fuel in the steam boiler, the water is heated into high-temperature and high-pressure steam, which drives the steam turbine to rotate and drives the generator to generate electricity; in the application of steam, in order to ensure that the steam will not be generated excessively If there is a lot of water, the high temperature state of the steam is often maintained, enters the header, and then distributes to each branch pipeline to facilitate the rational application of steam; in the existing high-temperature superheater inlet and outlet headers, most of them use headers There are many small tubes distributed around, the steam...

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Problems solved by technology

[0002] In thermal power generation enterprises, relying on the combustion of fuel in the steam boiler, the water is heated into high-temperature and high-pressure steam, which drives the steam turbine to rotate and drives the generator to generate electricity; in the application of steam, in order to ensure that the steam will not be generated excessively If there is a lot of water, the high temperature state of the steam is often maintained, enters the header, and then distributes to each branch pipeline to facilitate the rational application of steam; in the existing high-temperature superheater inlet and outlet headers, most of them use headers There are many small tubes distributed around, the steam pressure of the superheater is 13.7MPa, and the temperature is 540°C. The material of the high-temperature superheater header is 12Cr1MoV, and the common specifications are 325 mm in diameter and 50 mm in wall thickness. The material of the branch pipe is 12Cr1MoV, and the specification is The diameter is 42 mm, and the wall thickness is 5.5 mm. After working practice, it is found that there are often cracks at the root of the fourth pipe seat from the single row of the outlet header pipe seat of the high-temperature superheater. After repeated repairs, this branch pipe has become a high-temperature superheater. The outlet header is easy to damage the concentration point

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