CN-224229965-U - Deep peak regulation system configuration

CN224229965UCN 224229965 UCN224229965 UCN 224229965UCN-224229965-U

Abstract

The utility model provides a deep peak shaving system configuration, which is characterized in that a newly increased final-stage high-pressure heater and a newly increased external steam cooler are additionally arranged on a water supply pipeline on the basis of an existing boiler water supply heating system, a steam side inlet of the newly increased external steam cooler is connected with a temperature reduction module, steam with a higher pressure level than the regenerative steam extraction of a high-pressure cylinder is connected to an inlet of the temperature reduction module, steam at a steam side outlet of the newly increased external steam cooler is sent to the newly increased final-stage high-pressure heater, and the water supply heated by the existing final-stage high-pressure heater is additionally heated at the newly increased external steam cooler and in the newly increased final-stage high-pressure heater so as to improve the temperature of the water supply fed into a boiler of a unit under a deep peak shaving working condition, and simultaneously maintain a certain water supply pressure to maintain a certain supercooling degree of the water supply at an outlet of the economizer, so that the dry state of the boiler is maintained under a deep peak shaving working condition, and the water power stability is maintained, and the denitration system is continuously and stably put into operation.

Inventors

ZHANG LING
DU YANGYANG
WU YUE
SUN QING
SHANG QIANG
LU XIAOFENG
LIN CHEN
ZHU LI
CHEN LEI

Assignees

上海外高桥第三发电有限责任公司

Dates

Publication Date: 20260512
Application Date: 20250307

Claims (9)

1. The deep peak regulation system configuration comprises a boiler, an oxygen removal system, a high-pressure cylinder, an existing final-stage high-pressure heater, a water supply pipeline and a steam pipeline, and is characterized in that the boiler comprises an economizer, a water-cooled wall and a superheater which are sequentially connected through pipelines, the high-pressure cylinder adopts a partial steam inlet mode, the oxygen removal system, the existing final-stage high-pressure heater, a newly-added final-stage high-pressure heater and a newly-added external steam cooler are sequentially arranged in the water supply pipeline along the water supply flow direction, a water supply outlet of the newly-added external steam cooler is communicated with a boiler water inlet, the steam pipeline comprises a main steam pipeline connected between a boiler steam outlet and a steam inlet of the high-pressure cylinder and a steam extraction pipeline connected between the steam inlet of the high-pressure cylinder and a steam inlet of the existing final-stage high-pressure heater, an adjusting stage steam inlet valve group is arranged on the main steam pipeline, a steam side inlet of the newly-added external steam cooler is connected with a temperature reduction module, an inlet of the temperature reduction module is connected with a back-heating steam inlet of the newly-added external steam cooler, and a steam inlet of the newly-added external steam cooler is communicated with the steam inlet of the newly-added external steam cooler.
2. The depth peaking system configuration of claim 1, wherein the desuperheater module comprises an isolation valve, a pressure reducing valve, and a desuperheater connected in sequence by a pipeline, the desuperheater having desuperheater chilled water connected thereto.
3. The depth peaking system configuration of claim 2, wherein the steam pressure at the steam side outlet of the newly added external steam cooler is higher than the regenerative extraction pressure of the high pressure cylinder.
4. The depth peaking system configuration of claim 1, wherein the source of steam at a higher pressure level than the back-heated extraction steam of the high pressure cylinder is the main steam in the unit or the steam in the superheater system or the chamber after the high pressure cylinder conditioning stage or the main steam of the unit, the steam in the superheater system, or the mixed steam of any one of the chamber steam after the high pressure cylinder conditioning stage and the back-heated extraction steam or the reheat steam of the unit.
5. The depth peaking system configuration of claim 4, wherein a higher pressure level steam source than the high pressure cylinder's regenerative extraction steam is the local unit's main steam, the temperature reduction module's inlet is connected to the main steam line to introduce a portion of the main steam.
6. The depth peaking system configuration of claim 1, wherein the source of steam at a higher pressure level than the recuperated extraction steam of the high pressure cylinder is the primary steam in other units or the steam in the superheater system or the chamber after the high pressure cylinder conditioning stage or the primary steam in other units, the steam in the superheater system, the mixed steam of any one of the chamber steam after the high pressure cylinder conditioning stage and the recuperated extraction steam or the reheat steam.
7. The depth peaking system configuration of claim 1, wherein the number of valves of the tuning stage admission valve group is four or six.
8. The depth peaking system configuration of claim 2, wherein a heat exchanger is provided between the desuperheater outlet and the steam side inlet of the newly added external steam cooler.
9. The depth peaking system configuration of any one of claims 1-8, wherein a throttling assembly is provided in the feedwater or steam piping system from the economizer outlet to the high pressure cylinder inlet.

Description

Deep peak regulation system configuration Technical Field The utility model relates to the technical field of power generation, in particular to a deep peak shaving system configuration. Background Belongs to the technical field of power generation, in particular to a flexible operation system of a coal motor group for adapting to deep peak shaving. At present, super (super) critical units with high parameters, large capacity, high efficiency and low carbon become the main stream of new unit options in thermal power plants. For ultra (supercritical) units, the capacity is mainly 350MW, 660MW and 1000MW, and the capacity is also a small amount of 1200MW and 1350 MW. In recent years, the installed capacity and the generated energy of new energy are newly created to be high, but because the generated energy of the new energy generation mode has uncertainty of the generated energy, the traditional thermal power generating unit, especially the coal-fired thermal power generating unit, still has to take the roles of basic guarantee power supply and flexible peak regulation power supply matched with the new energy for generating. Taking a certain 1000MW ultra-supercritical unit as an example, a high-pressure cylinder adopts a partial steam inlet mode to configure an adjusting stage, the dispatching load range of a regional power grid is 40% -100% THA, and the water supply flow of boiler equipment corresponding to the unit load is higher than the minimum flow for keeping the boiler to run in a dry state, so that the boiler always keeps running in the dry state and does not have a dry-wet state conversion process in the current normal load dispatching range. However, with the rapid development of new energy, the regional power grid has now notified that the unit needs deep peak shaving cloud operation, and the lower limit of load scheduling needs to be as low as 20%, and the water supply flow of the boiler equipment corresponding to the 20% load of the unit is already lower than the minimum flow of the boiler kept in dry state operation, so that the boiler will have to be converted into wet state operation. For the supercritical unit (supercritical) which needs to participate in the deep peak shaving operation, and the high-pressure cylinder adopts a partial steam inlet mode to configure the regulation stage, when the deep peak shaving load range is 20% -30% THA, even lower, the following problems are faced: (1) Under the deep peak regulation working condition, the dry state and the wet state of the boiler are frequently converted, the control of coal, water and wind is very difficult, and the non-stopping risk of the boiler is rapidly increased; (2) Under the deep peak-shaving working condition, the enthalpy of the water supply at the inlet of the water-cooled wall is increased, the water dynamic stability of the water-cooled wall of the boiler is poor, the risk of overtemperature pipe explosion of the water-cooled wall is increased sharply; (3) Under the deep peak regulation working condition, the outlet smoke temperature of the economizer is lower than the lower temperature limit of normal operation of the denitration catalyst, such as 300 ℃, the denitration system cannot operate normally, the emission of NO X is predicted to be exploded and is far higher than the standard requirement value, such as the emission index is exploded from 25mg/Nm 3 to more than 200mg/Nm 3, and the emission index is far beyond the standard value of 50mg/Nm 3. (4) Under the wet running condition of the boiler, if the water separated from the steam-water separator at the outlet of the water-cooled wall of the boiler is directly discharged to the atmospheric expansion vessel, a large amount of working medium and energy loss are caused, the energy consumption of a unit is greatly increased, and the running economy is greatly reduced. Therefore, how to maintain the dry running of the boiler under the deep peak-shaving working condition, and keep the hydrodynamic stability and the continuous and stable operation of the denitration system becomes a problem to be solved. Disclosure of utility model The utility model aims to solve the technical problems of maintaining dry running of a boiler under a deep peak shaving working condition of a supercritical unit, maintaining hydrodynamic stability and continuously and stably putting a denitration system into operation, and provides a deep peak shaving system configuration. The utility model solves the technical problems by the following technical scheme: The utility model provides a deep peak regulation system configuration which comprises a boiler, a deoxidization system, a high-pressure cylinder, an existing final-stage high-pressure heater, a water supply pipeline and a steam pipeline, wherein the boiler comprises an economizer, a water-cooled wall and a superheater which are sequentially connected through pipelines, the high-pressure cylinder adopts a partial steam inlet mode, the deoxidizatio