Grinding tool and grinding method for reheating main valve seat of steam turbine

Abstract

The invention discloses a grinding tool for a reheating main valve seat of a steam turbine. The reheating main valve seat of the steam turbine comprises a cylinder body, wherein a conical valve port is formed at the bottom of the cylinder body. The grinding tool comprises a screw rod, wherein the top of the screw rod is provided with a handle, while the bottom is provided with a conical lapper; the conical lapper adapts to the conical valve port; the screw rod passes through a guide flange and is connected with the guide flange in a sliding way; a nut is arranged above the guide flange and is in threaded connection with the screw rod; and a spring is arranged between the nut and the guide flange. The guiding tool performs guide positioning on the screw rod by using the guide flange, so that the conical lapper and the conical valve port are matched with each other more tightly and better grinding effect is achieved. The length of the screw rod in the cylinder body can be adjusted conveniently through the spring and the nut, so that the conical lapper is prevented from being collided with the grinding surface of the conical valve port and the conical valve port is prevented from being damaged. The invention has the advantages that: the grinding tool has a simple structure, is convenient to manufacture, and is reliable and practical.

Description

technical field [0001] The invention relates to a grinding tool and a grinding method, in particular to a grinding tool used for reheating a main steam valve seat of an ultra-supercritical 1000MW steam turbine and a grinding method using the grinding tool. Background technique [0002] The sealing of the reheat main valve seat of an ultra-supercritical 1000MW steam turbine plays a vital role in the operation of the steam turbine. When the seal of the reheat main valve seat fails, it is necessary to grind the reheat main valve seat to make it Achieve resealable effect. However, since the machining surface of the reheated main valve seat of an ultra-supercritical 1000MW steam turbine is made of cemented carbide material, the hardness is high, and a material with higher hardness than cemented carbide should be used for effective grinding. The material is softer than the material (tungsten carbide) on the surface of the reheated main valve seat, so it is difficult to achieve th...

AI Technical Summary

Problems solved by technology

However, since the machining surface of the reheated main valve seat of an ultra-supercritical 1000MW steam turbine is made of cemented carbide material, the hardness is high, and a material with higher hardness than cemented carbide should be used for effective grinding. The material is softer than the material (tungsten carbide) on the surface of the reheated main valve seat, so it is difficult to achieve the grinding effect by using the existing common grinding tool to directly grind the surface of the reheated main valve seat. As a result, sometimes there will even be a problem that the grinding tool is ground by the reheated main valve seat, which makes the loss of the grinding tool very large, and the use of this grinding tool requires a lot of physical strength

If sand tiles are used to grind them, because the processing surface of the reheated main valve seat is an inner cone surface, it is difficult to manufacture tools such as sand tiles, it is not easy to grind, and the processing accuracy is not high

And because the material and shape of the main valve seat are special, there is no special tool to grind it at present, so the accuracy and efficiency of grinding are relatively poor, so it is urgent to develop a tool that can guarantee the processing shape. The grinding tool that can ensure the bit accuracy and ensure the processing efficiency

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