An integral double-layer low-pressure inner cylinder of a steam turbine

Abstract

The invention discloses an integral double-layer low-pressure inner cylinder of a steam turbine, which comprises an outer inner cylinder, an inner inner cylinder, a steam inlet chamber and a partition sleeve; the outer inner cylinder, the inner inner cylinder, the air intake chamber and the partition sleeve are cast or welded as a whole; there are several regenerative steam extraction chambers and corresponding regenerative steam extraction ports arranged on both sides of the steam inlet chamber; the steam inlet chamber has a steam inlet and a steam inlet annular channel; the steam inlet annular There is a complete circle of inner and inner cylinders between the channel and the low-pressure first heat recovery steam extraction port of the outer and inner cylinders, forming a steam expansion flow channel to both ends. In the present invention, by setting up a complete circle of inner cylinders, using the lower space of the low-pressure inner cylinders to arrange low-pressure-regeneration steam extraction ports, the low-pressure steam intake and high-temperature parts can be cooled by reheating and low-pressure steam extraction, and the thermal stress is greatly reduced; There is no need to set up additional cooling steam introduction and drainage systems, and it will not cause interstage steam leakage; at the same time, the number of suction port openings is reduced, the structure is simplified, and the sealing reliability, durability and economy of the low-pressure inner cylinder are improved.

Description

technical field [0001] The invention relates to the structure of a low-pressure inner cylinder of a steam turbine, in particular to an integral double-layer low-pressure inner cylinder of a steam turbine. Background technique [0002] With the development of high-parameter and large-capacity steam turbines, the size of the low-pressure inner cylinder is getting larger and larger, and its rigidity and air-tightness requirements are getting higher and higher. However, the traditional low-pressure inner cylinder has complex structures, poor air-tightness, and easy deformation. , Poor reliability and other issues. The details are as follows: [0003] 1. In the single-layer low-pressure inner cylinder structure of the assembled steam inlet chamber, the radial matching surface of the steam inlet chamber and the low-pressure inner cylinder is connected by a key, and the connection part is provided with radial and axial thermal expansion gaps; The other connecting parts of the inn...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to solve the technical problems existing in the low-pressure inner cylinder of the above-mentioned large-scale unit, and provide an integral double-layer low-pressure inner cylinder of a steam turbine, which not only solves the problem of deformation and leakage of the low-pressure inner cylinder of the large-scale unit, but also solves the problem of low-pressure steam extraction Improve the reliability and economy of the long-term operation of the unit

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