A method for treating the deformation of the joint surface of the steam turbine cylinder

Abstract

The invention relates to a steam turbine cylinder joint surface deformation processing method. The method comprises following steps:1) sending a low-pressure inner upper cylinder to a steam turbine factory for machining and rubbing down; 2) polishing the lower cylinder joint surface of a low-pressure inner lower cylinder based on the machined inner upper half cylinder; 3) cleaning burrs on the machined cylinder surface and traces remained by the machining; 4) hoisting all carrier rings and separator plates in the lower cylinder; 5) cleaning the surface of the lower cylinder; 6) making analysis according to measured results and traces pressed on the lower cylinder joint surface; 7) employing a mechanical polishing tool to polish the lower cylinder joint surface from the thickest position to be polished and gradually and radially enlarging the polishing area, wherein the joint surface is repeatedly polished in the vertical and horizontal directions by a long flat ruler during each polishing process; 8) finely polishing the joint surface when a set scraping value of a depth mark is remained; and 9) repeating the step 8) until the joint surface gap value meets requirements. Compared with the prior art, the cylinder deformation can be completely eliminated through the method, and the maintenance is convenient and reliable.

Description

technical field

[0001] The invention relates to a steam turbine maintenance technology, in particular to a method for treating the deformation of the joint surface of a steam turbine cylinder. Background technique

[0002] After a certain operation period of the steam turbine, the cylinder block will be more or less deformed to a certain extent. The most intuitive manifestation is that the face of the cylinder will cause a large gap, and steam leakage on the cylinder surface and channeling between stages will occur during operation. The steam turbine operates safely and stably and reduces the thermal efficiency of the unit; at the same time, in the maintenance process, considerable manpower and material resources must be invested in order to eliminate the deformation, and it is technically difficult to guarantee the quality.

[0003] There are many factors that cause the deformation of the cylinder, which are related to the design of the cylinder body; the quality of the mat...

Examples

Embodiment

[0030] Taking Jiangyin Ligang #4 unit as an example for A-level maintenance of high and medium pressure outer cylinders

[0031] 1. State before repair: Unit #4 of Jiangyin Ligang Power Generation Co., Ltd., the 350MW steam turbine model is TC2F-38.6, which is a subcritical, one-time intermediate reheat, single-shaft and double-exhaust steam condensation supplied and designed by Westinghouse Electric Co., Ltd. Steam turbine unit. The unit was put into operation in 1998, and it was overhauled for the first time in 2003. During the overhaul, it was found that the gap between the horizontal joint surface of the high and medium pressure outer cylinder was seriously exceeded. The value is 0.10mm. The maximum change in the upper and lower radial clearances of the dynamic and static parts before and after tightening the bolts exceeds 1.5mm. Steam leakage occurs at the front shaft seal of the high and medium pressure cylinder during operation. The unit underwent a second overhaul i...

technical field

[0001] The invention relates to a steam turbine maintenance technology, in particular to a method for treating the deformation of the joint surface of a steam turbine cylinder. Background technique

[0002] After a certain operation period of the steam turbine, the cylinder block will be more or less deformed to a certain extent. The most intuitive manifestation is that the face of the cylinder will cause a large gap, and steam leakage on the cylinder surface and channeling between stages will occur during operation. The steam turbine operates safely and stably and reduces the thermal efficiency of the unit; at the same time, in the maintenance process, considerable manpower and material resources must be invested in order to eliminate the deformation, and it is technically difficult to guarantee the quality.

[0003] There are many factors that cause the deformation of the cylinder, which are related to the design of the cylinder body; the quality of the mat...

Examples

Embodiment

[0030] Taking Jiangyin Ligang #4 unit as an example for A-level maintenance of high and medium pressure outer cylinders

[0031] 1. State before repair: Unit #4 of Jiangyin Ligang Power Generation Co., Ltd., the 350MW steam turbine model is TC2F-38.6, which is a subcritical, one-time intermediate reheat, single-shaft and double-exhaust steam condensation supplied and designed by Westinghouse Electric Co., Ltd. Steam turbine unit. The unit was put into operation in 1998, and it was overhauled for the first time in 2003. During the overhaul, it was found that the gap between the horizontal joint surface of the high and medium pressure outer cylinder was seriously exceeded. The value is 0.10mm. The maximum change in the upper and lower radial clearances of the dynamic and static parts before and after tightening the bolts exceeds 1.5mm. Steam leakage occurs at the front shaft seal of the high and medium pressure cylinder during operation. The unit underwent a second overhaul i...

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