A method for controlling the main steam temperature of an ultra-supercritical unit

By installing extraction steam throttling valves on the extraction steam pipeline of ultra-supercritical units, the throttling flow rate of high-pressure heater extraction steam is precisely controlled, solving the problem of excessive main steam temperature and improving the unit's load-changing capacity and flexibility.

CN119554110BActive Publication Date: 2026-05-26HUANENG PINGLIANG POWER GENERATION CO LTD +2
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
HUANENG PINGLIANG POWER GENERATION CO LTD
Filing Date
2024-12-09
Publication Date
2026-05-26

AI Technical Summary

Technical Problem

The main steam temperature is prone to exceed the limit during the rapid load increase of ultra-supercritical units, which limits the improvement of unit flexibility and is difficult to control effectively with existing technologies.

Method used

By installing extraction steam throttling valves on the extraction steam pipelines of each stage of the ultra-supercritical unit, the heat absorption of feedwater and steam can be adjusted by precisely controlling the extraction steam flow rate of the high-pressure heater, thereby achieving a rapid and precise reduction in the main steam temperature.

Benefits of technology

It effectively prevents the main steam temperature from exceeding the limit, eliminates the bottleneck of main steam temperature exceeding the limit, improves the unit's operational flexibility, and simplifies automated control operations.

✦ Generated by Eureka AI based on patent content.

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    Figure CN119554110B_ABST
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Abstract

This invention discloses a method for controlling the main steam temperature of an ultra-supercritical unit. An extraction valve is added to the extraction steam pipeline of the high-pressure heater to achieve precise extraction steam throttling adjustment. Thermodynamic parameters of the boiler and turbine systems are collected and cleaned. The feedwater heating insufficiency and reheat steam flow rate changes corresponding to the unit extraction steam throttling flow rate under different high-pressure heater extraction steam throttling schemes are calculated. Furthermore, the heat absorption changes of the economizer and part of the superheater heating surfaces after the reheater are calculated. Finally, the predicted value of the main steam temperature change corresponding to the unit extraction steam throttling flow rate under different high-pressure heater extraction steam throttling schemes is obtained. Based on the real-time deviation of the main steam temperature, the high-pressure heater extraction steam throttling scheme and the required extraction steam throttling flow rate are selected. By adjusting the extraction steam throttling flow rate of each high-pressure heater, more precise control of the main steam temperature is achieved, alleviating the problem of main steam overheating that easily occurs during rapid load increases. This is of great significance for improving the operational flexibility of ultra-supercritical units.
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