Steam turbine and method for reducing operating temperature of outer cylinder of steam turbine

Abstract

The invention discloses a steam turbine and a method for reducing the operating temperature of an outer cylinder of the steam turbine. A high temperature steam outlet channel and a low temperature steam return channel are arranged between the front end steam sealing interval and the back end through flow stage of the steam turbine, a steam inlet of the high temperature steam outlet channel is formed in a steam sealing body on the front end steam sealing interval, and a steam outlet of the high temperature steam outlet channel is formed in the back end through flow stage; and a steam inlet of the low temperature steam return channel is formed in the back end through flow stage, located on the inner side of the steam outlet of the high temperature steam outlet channel, and separated by morethan one through flow stage, and the steam outlet of the low temperature steam return channel is formed in the steam sealing body of the front end steam sealing interval, located on the outer side ofthe steam inlet of the high temperature steam outlet channel, and separated by more than one ring of steam sealing body. The outer cylinder no longer bears the higher operating temperature and can bemade from the low-grade materials, the requirements of the resistance to high temperature of the outer cylinder are reduced, the costs of production and manufacturing are greatly reduced accordingly,and the high economic benefits are achieved.

Description

technical field [0001] The invention belongs to the technical field of steam turbines, in particular to a steam turbine and a method for reducing the working temperature of the outer cylinder of the steam turbine. Background technique [0002] The steam turbine is a high-speed rotating power machine. There is a certain gap between the stationary part and the rotating part of the steam turbine. In order to reduce the steam leakage in the dynamic and static gap, a steam seal device is installed. According to different installation positions, it is divided into end steam seal, diaphragm steam seal and blade top steam seal. The steam is an isentropic throttling process in the steam seal flow channel, basically the pressure drops and the temperature changes little. Generally, most steam turbines are divided cylinders for high and medium pressure, single-flow, and double-layer cylinder structure. The steam temperature at the entrance of the front end seal of a single-flow double...

AI Technical Summary

Problems solved by technology

With the continuous improvement of the steam inlet parameters of the steam turbine, the working temperature of the outer cylinder will be higher and higher, and the outer cylinder needs to choose better materials, which will inevitably lead to a great increase in the production cost of the outer cylinder

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