Method and system for adjusting and controlling exhaust steam pressure of high-pressure cylinder for steam extraction and heat supply of resteam device

Abstract

The invention discloses a method for adjusting and controlling exhaust steam pressure of a high-pressure cylinder for steam extraction and heat supply of a resteam device. The method comprises the following steps that in a starting stage of a steam turbine unit, the opening degree is adjusted by a high regulating valve and a middle regulating valve together to control the rotating speed of a steam turbine, after grid connection, the middle regulating valve is kept in a sufficient opening state, and only the high regulating valve adjusts the opening degree to control the load of the unit; external steam extraction and heat supply are added to a cold section and a hot section of a reheater respectively; a relation curve of high-pressure cylinder blade-level pressure and a high-pressure cylinder exhaust steam pressure limit value is obtained, the high-pressure cylinder exhaust steam pressure limit value is calculated according to the high-pressure cylinder blade-level pressure, and a high-pressure cylinder exhaust steam pressure control target value is obtained; high-pressure cylinder exhaust steam real-time pressure is obtained, and the high-pressure cylinder exhaust steam real-time pressure is compared with a control target value; when the real-time pressure is larger than the control target value, the opening degree of the middle regulating valve is controlled to be increased; and when the real-time pressure is smaller than the control target value, the opening degree of the middle regulating valve is controlled to be smaller until the real-time pressure is equal to the control target value. Through pressure building control of the middle regulating valve, the high-pressure cylinder exhaust steam pressure can be rapidly adjusted.

Description

technical field [0001] The invention belongs to the technical field of steam turbine control, and in particular relates to a method and system for adjusting and controlling the exhaust pressure of a high-pressure cylinder under the condition of extracting steam from a cold section and a hot section of a reheater for a 660MW ultra-supercritical steam turbine unit. Background technique [0002] Shanghai Turbine Plant 660MW ultra-supercritical steam turbine type: ultra-supercritical, one-time intermediate reheat, three-cylinder two-exhaust steam, single-shaft, indirect air-cooled steam unit, eight-stage regenerative steam extraction. The 660MW ultra-supercritical steam turbine unit includes main steam valve, high-pressure cylinder, high-pressure valve, medium-pressure cylinder, middle main door, middle-pressure valve, medium-low pressure connecting pipe low-pressure cylinder and generator. After the steam passes through the high-pressure valve and the single-flow high-pressure ...

AI Technical Summary

Problems solved by technology

According to the original operation mode, the exhaust pressure of the high-pressure cylinder cannot be adjusted quickly, so that the safe, reliable and economical operation of the unit for power generation and heating cannot be guaranteed

Images