Operating a system configuration

Abstract

The utility model provides an operation system configuration which is characterized in that on the basis of an existing boiler feed water heating system, a newly-added final-stage high-pressure heater and a newly-added external steam cooler are additionally arranged on a water supply pipeline, and a steam side inlet of the newly-added external steam cooler is connected with a temperature reduction module; steam with the pressure grade higher than that of regenerative extraction steam of the high-pressure cylinder is introduced into an inlet of the temperature reduction module, and feed water is subjected to two-time supplementary heating in the newly-added external steam cooler and the newly-added final-stage high-pressure heater, so that the temperature of feed water entering a furnace of the unit under the deep peak regulation working condition is increased; and meanwhile, certain feed water pressure is maintained, and feed water at an outlet of the economizer is kept at a certain supercooling degree, so that the denitration system of the unit can be continuously and stably put into operation under the deep peak regulation working condition, the energy consumption of the unit is prevented from being greatly increased, and the operation economy of the unit is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of electrical technology, and in particular to an operating system configuration. Background Technology

[0002] Currently, high-parameter, large-capacity, high-efficiency, and low-carbon ultra-supercritical units have become the mainstream choice for new thermal power plant units. However, among the existing units, there are approximately 1,000 subcritical units in the 300,000-600,000 kW range, with an installed capacity of about 350 million kW.

[0003] In recent years, the installed capacity and power generation of new energy sources have reached new highs. However, due to the uncertainty of power generation from new energy sources, traditional thermal power units, especially coal-fired power units, still need to play the role of basic backup power supply and flexible peak-shaving power supply in coordination with new energy power generation.

[0004] Taking a 300MW subcritical unit (with a partial steam inlet in the high-pressure cylinder and a regulating stage) as an example, the power grid dispatch load range in this region is 40%-100% THA. However, with the rapid development of new energy sources, the power grid in this region has now notified the unit that it needs to operate under deep peak shaving, and the lower limit of load dispatch needs to be as low as 20%.

[0005] For subcritical units that need to participate in deep peak shaving operation, such as those with a load variation range of 20%-100% THA, where the deep peak shaving load range is 20%-30% THA or even lower (using partial steam intake in the high-pressure cylinder and equipped with a regulating stage), the following problems will be faced:

[0006] (1) Under deep peak-shaving conditions, the economizer outlet flue gas temperature will be lower than the lower limit of the normal operating temperature of the denitrification catalyst, such as 300℃. The denitrification system will not be able to operate normally, and NO is expected to rise. X Emissions will surge and far exceed standard requirements, such as the emission limit being raised from 25 mg / Nm³. 3 The concentration of Nm2 surged to 200 mg / Nm3 3 The above levels far exceed the standard value of 50 mg / Nm³. 3 .

[0007] (2) The boiler drum outlet temperature drops significantly, the main and reheat steam temperatures will decrease significantly, the unit energy consumption will increase significantly, and the operating economy will decrease significantly.

[0008] Therefore, how to maintain the continuous and stable operation of the denitrification system under deep peak shaving conditions for subcritical units, and avoid a significant increase in unit energy consumption and a significant decrease in operating economy, has become an urgent problem to be solved. Utility Model Content

[0009] The technical problem to be solved by this utility model is to overcome the defects of subcritical units under deep peak shaving conditions, such as the inability of the denitrification system to operate normally, a significant increase in unit energy consumption, and a significant decrease in operating economy, and to provide an operating system configuration.

[0010] The present invention solves the above-mentioned technical problems through the following technical solution:

[0011] This utility model provides an operating system configuration, comprising: a boiler, a deaerator system, a high-pressure cylinder, an existing final-stage high-pressure heater, a feedwater pipeline, and a steam pipeline. The boiler includes an economizer, a steam drum, a superheater, a header, a downcomer, and a water-cooled wall. The economizer, steam drum, and superheater are connected sequentially via pipelines. Water from the lower part of the steam drum flows through the downcomer to the header, is heated by the water-cooled wall, and then returns to the steam drum. The high-pressure cylinder uses a partial steam intake method. In the feedwater pipeline, along the feedwater flow direction, a deaerator system, an existing final-stage high-pressure heater, a newly added final-stage high-pressure heater, a newly added external steam cooler, and a newly added external... The feedwater outlet of the steam cooler is connected to the boiler feedwater inlet; the steam pipeline includes a main steam pipeline connecting the boiler steam outlet and the high-pressure cylinder inlet, and an extraction steam pipeline connecting the high-pressure cylinder extraction steam outlet and the existing final-stage high-pressure heater inlet; the main steam pipeline is equipped with a regulating stage inlet valve group, and the extraction steam pipeline is equipped with an extraction steam isolation valve; the steam-side inlet of the newly added external steam cooler is connected to a desuperheating module, and the inlet of the desuperheating module is connected to steam with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder; the steam-side outlet of the newly added external steam cooler is connected to the inlet of the newly added final-stage high-pressure heater.

[0012] In this scheme, based on the existing boiler feedwater heating system, a new final-stage high-pressure heater and a new external steam cooler are added to the feedwater pipeline between the existing final-stage high-pressure heater and the boiler feedwater inlet. A desuperheating module is connected to the steam-side inlet of the new external steam cooler. The inlet of the desuperheating module receives steam with a higher pressure level than the regenerative extraction steam from the high-pressure cylinder. After being desuperheated and depressurized by the desuperheating module, the steam first heats the feedwater in the new external steam cooler. Then, the steam from the steam-side outlet of the new external steam cooler is sent to the new final-stage high-pressure heater to supplement the feedwater heated by the existing final-stage high-pressure heater, thereby increasing the feedwater temperature entering the boiler under deep peak-shaving conditions. In addition to the existing high-pressure heater at the final stage heating the feedwater, steam with a higher pressure level than the regenerative extraction steam from the high-pressure cylinder is introduced for supplementary heating twice, in both the newly added external steam cooler and the newly added high-pressure heater at the final stage. This increases the feedwater temperature into the boiler under deep peak shaving conditions, thereby increasing the economizer inlet water temperature, economizer outlet water temperature, economizer outlet flue gas temperature, and steam drum outlet steam temperature. This facilitates the continuous and stable operation of the denitrification system under deep peak shaving conditions, avoids a significant increase in unit energy consumption, effectively improves the unit's operating economy, and avoids large-scale modifications to the boiler and turbine thermal systems. It also better adapts to the wide load range of the unit's response to deep peak shaving in the power grid, while improving the unit's operating economy and flexibility.

[0013] Preferably, the cooling module includes an isolation valve, a pressure reducing valve, and a cooler connected in sequence by pipes, with cooling water connected to the cooler.

[0014] In this scheme, steam with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder enters the desuperheating module, is depressurized by the pressure reducing valve, and then enters the desuperheater to mix with desuperheating water to achieve desuperheating and pressure reduction. Through the function of the desuperheating module, the steam with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is desuperheated and depressurized, ensuring the safe operation of the system.

[0015] Preferably, the steam pressure at the steam-side outlet of the newly added external steam cooler is higher than the regenerative extraction steam pressure of the high-pressure cylinder.

[0016] In this scheme, the steam pressure at the steam outlet of the newly added external steam cooler is higher than the regenerative extraction pressure of the high-pressure cylinder, which makes the steam pressure entering the newly added final-stage high-pressure heater higher than the regenerative extraction pressure of the high-pressure cylinder, thereby achieving supplementary heating of the feedwater that has been heated by the existing final-stage high-pressure heater at the newly added final-stage high-pressure heater.

[0017] Preferably, the boiler is equipped with a circulating pump in the downcomer connecting the steam drum and the header.

[0018] In this scheme, a circulation pump is installed in the downcomer connecting the steam drum and the header to enhance the driving force of the working fluid circulation flow, so that the water in the lower part of the steam drum can flow smoothly through the downcomer to the header.

[0019] Preferably, the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is a mixture of the main steam of the unit, the steam in the superheater system, the steam in the rear chamber of the high-pressure cylinder regulating stage, or any one of the main steam, the steam in the superheater system, and the steam in the rear chamber of the high-pressure cylinder regulating stage, with the regenerative extraction steam or reheat steam of the unit.

[0020] This solution makes full use of the steam in the unit and provides multiple options for steam sources with higher pressure levels than the regenerative extraction steam of the high-pressure cylinder. Under the premise that the steam entering the newly added external steam cooler is higher than the existing regenerative extraction steam, the operational flexibility of the unit is improved.

[0021] Preferably, the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is the main steam of the unit, and the inlet of the desuperheating module is connected to the main steam pipeline to introduce part of the main steam.

[0022] In this scheme, the inlet of the desuperheating module is connected to the main steam pipeline. By introducing a portion of the main steam into the desuperheating module, the steam is desuperheated and depressurized before being sent to an external steam cooler to heat the feedwater, thereby increasing the feedwater temperature of the unit under deep peak shaving conditions.

[0023] Preferably, the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is a mixture of main steam from other units, steam in the superheater system, steam in the regulating chamber of the high-pressure cylinder, or steam in the main steam, steam in the superheater system, or steam in the regulating chamber of the high-pressure cylinder, and regenerative extraction steam or reheat steam.

[0024] In this scheme, steam from other units is used to improve the operational flexibility of the unit and optimize the thermodynamic cycle of the entire system, provided that the steam entering the newly added external steam cooler is higher than that of the existing regenerative extraction steam.

[0025] Preferably, the number of valves in the regulating stage inlet valve group is four or six.

[0026] In this scheme, the number of valves in the regulating stage inlet valve group is four or six. By regulating the main steam flow through multiple valves, not only is the flow control accuracy high, but the flow of a single valve is relatively small, which makes the pressure control of the main steam more precise and convenient.

[0027] Preferably, the operating system is configured to: throttle the main steam using the regulating stage inlet steam valve group to maintain a certain feedwater pressure and keep the economizer outlet feedwater at a certain degree of subcooling.

[0028] In this scheme, steam with a higher pressure rating than the regenerative extraction steam from the high-pressure cylinder is de-cooled and depressurized in the de-cooling module before entering the newly added external steam cooler to supplement the feedwater heating. It also enters the newly added final-stage high-pressure heater after the external steam cooler to supplement the feedwater heating, thereby increasing the unit's feedwater temperature under deep peak-shaving conditions. The regulating stage inlet steam valve group is used to throttle the main steam to maintain a certain feedwater pressure and keep the economizer outlet feedwater at a certain degree of subcooling. Furthermore, while controlling the main steam, the regulating stage inlet steam valve group also achieves a certain steam enthalpy drop, thus relatively improving the unit's economic efficiency.

[0029] Preferably, a throttling component is installed in the feedwater or steam pipeline system from the economizer outlet to the high-pressure cylinder inlet, and the throttling component is adjusted to maintain a certain feedwater pressure.

[0030] In this scheme, throttling components, such as regulating valves, can be installed in the feedwater or steam pipeline from the economizer outlet to the high-pressure cylinder inlet to maintain a certain feedwater pressure, thereby keeping the economizer outlet feedwater at a certain degree of subcooling.

[0031] The positive and progressive effects of this utility model are as follows: Based on the existing boiler feedwater heating system, a new final-stage high-pressure heater and a new external steam cooler are added to the feedwater pipeline between the existing final-stage high-pressure heater and the boiler feedwater inlet. A desuperheating module is connected to the steam-side inlet of the new external steam cooler. The inlet of the desuperheating module receives steam with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder. After the desuperheating and pressure reduction effect of the desuperheating module, the steam first heats the feedwater in the new external steam cooler. Then, the steam at the steam-side outlet of the new external steam cooler is sent to the new final-stage high-pressure heater to supplement the feedwater that has been heated by the existing final-stage high-pressure heater. This increases the feedwater temperature at the boiler inlet under deep peak shaving conditions and simultaneously maintains a certain feedwater pressure to keep the economizer outlet feedwater at a certain degree of subcooling. This enables the denitrification system of the unit to operate continuously and stably under deep peak shaving conditions, avoids a significant increase in unit energy consumption, and effectively improves the unit's operating economy. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a boiler feedwater heating system in the prior art.

[0033] Figure 2 This is the operating system configuration of one embodiment of the present utility model. Detailed Implementation

[0034] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0035] Figure 1 This is a schematic diagram of a boiler feedwater heating system in the prior art. The system includes a boiler, a deaerator system, a high-pressure cylinder, and an existing final-stage high-pressure heater. The boiler includes an economizer, a steam drum, a superheater, a header, a downcomer, and water-cooled walls. The economizer, steam drum, and superheater are connected sequentially by pipelines. Water from the lower part of the steam drum flows through the downcomer to the header, is heated by the water-cooled walls, and then returns to the steam drum. The deaerator system includes a deaerator, a booster pump, and a feedwater pump. The high-pressure cylinder uses a partial steam inlet method and is equipped with a regulating stage. A regulating stage inlet valve group is arranged on the main steam pipeline. An extraction steam isolation valve is installed on the inlet pipeline connecting the high-pressure cylinder and the existing final-stage high-pressure heater. The steam source for the existing final-stage high-pressure heater is the final-stage extraction steam from the high-pressure cylinder. During system operation: the low-pressure condensate from the deaerator outlet is pressurized sequentially by the booster pump and the feedwater pump before entering the high-pressure heater for heating. The heated feedwater enters the boiler, is further heated by the economizer, and then enters the steam drum. The steam-water mixture undergoes steam-water separation in the steam drum. Specifically, the water in the lower part of the steam drum flows through the downcomer to the header, is heated by the water-cooled wall, and then returns to the steam drum. The wet saturated steam in the upper part of the steam drum enters the superheater and other heating surfaces for heating, and finally obtains the main steam which enters the high-pressure cylinder to do work.

[0036] To overcome the shortcomings of subcritical units under deep peak-shaving conditions, such as the inability of the denitrification system to operate normally, a significant increase in unit energy consumption, and a substantial decrease in operating economy, this utility model provides an operating system configuration, such as... Figure 2As shown, this utility model, based on an existing boiler feedwater heating system and with the existing final-stage high-pressure heater normally in operation for feedwater heating (i.e., the extraction steam isolation valve is open), sequentially installs a deaeration system, an existing final-stage high-pressure heater, a newly added final-stage high-pressure heater, and a newly added external steam cooler in the feedwater pipeline. The feedwater outlet of the newly added external steam cooler is connected to the boiler feedwater inlet. The steam pipeline includes a main steam pipeline connecting the boiler steam outlet and the high-pressure cylinder inlet, and an extraction steam pipeline connecting the high-pressure cylinder extraction steam outlet and the existing final-stage high-pressure heater inlet. The steam-side inlet of the newly added external steam cooler is connected to a desuperheating module, and the inlet of the desuperheating module receives steam with a higher pressure level than the regenerative extraction steam from the high-pressure cylinder. The steam-side outlet of the newly added external steam cooler is connected to the newly added final-stage high-pressure heater. Steam with a higher pressure rating than the regenerative extraction steam from the high-pressure cylinder is introduced into the inlet of the pressure heater. After being depressurized and de-cooled by the desuperheating module, the steam first heats the feedwater in the newly added external steam cooler. Then, the steam from the steam-side outlet of the newly added external steam cooler is sent to the newly added final-stage high-pressure heater to supplement the feedwater that has been heated by the existing final-stage high-pressure heater, thereby increasing the feedwater temperature of the unit under deep peak shaving conditions. By introducing steam with a higher pressure rating than the regenerative extraction steam from the high-pressure cylinder for supplementary heating twice, in the newly added external steam cooler and the newly added final-stage high-pressure heater, the feedwater temperature of the unit under deep peak shaving conditions is increased. At the same time, the regulating stage inlet steam valve group installed on the main steam pipeline is used to throttle the main steam to maintain a certain feedwater pressure and keep the feedwater at the economizer outlet at a certain degree of subcooling. Under deep peak shaving conditions, the feedwater temperature of the unit increases, which in turn increases the economizer inlet water temperature, economizer outlet water temperature, economizer outlet flue gas temperature, and steam drum outlet steam temperature. This facilitates the continuous and stable operation of the denitrification system under deep peak shaving conditions, avoids a significant increase in unit energy consumption, effectively improves the unit's operating economy, and avoids large-scale modifications to the boiler and turbine thermal systems. It also better adapts to the wide load range of the unit's response to deep peak shaving of the power grid, while improving the unit's operating economy and flexibility.

[0037] Figure 2 The number of valves in the intermediate regulating stage steam inlet valve group is four, but it can also be set to six. By regulating the main steam flow through multiple valves, the main steam flow can be controlled, and a certain steam enthalpy drop can be obtained, which improves the economic efficiency of the unit. Not only is the flow control accuracy high, but the flow of a single valve is relatively small, making the pressure control of the main steam more precise and convenient.

[0038] Of course, in other embodiments, throttling components, such as regulating valves, can be installed in the water supply line or steam line from the economizer outlet to the high-pressure cylinder inlet to maintain a certain water supply pressure, thereby keeping the economizer outlet water supply at a certain degree of subcooling.

[0039] Figure 2 The desuperheating module includes an isolation valve, a pressure reducing valve, and a desuperheater connected sequentially by pipes. Desuperheating water is introduced into the desuperheater. Steam with a higher pressure rating than the regenerative extraction steam from the high-pressure cylinder enters the desuperheating module, where it is depressurized by the pressure reducing valve and then mixed with the desuperheating water in the desuperheater to achieve desuperheating and pressure reduction. Through the action of the desuperheating module, the steam with a higher pressure rating than the regenerative extraction steam from the high-pressure cylinder is desuperheated and depressurized, ensuring the safe operation of the system.

[0040] The steam pressure at the steam outlet of the newly added external steam cooler is higher than the regenerative extraction pressure of the high-pressure cylinder, which makes the steam pressure entering the newly added final stage high-pressure heater higher than the regenerative extraction pressure of the high-pressure cylinder, thereby enabling supplementary heating of the feedwater that has been heated by the existing final stage high-pressure heater at the newly added final stage high-pressure heater.

[0041] Although Figure 2 In this embodiment, the water in the boiler drum flows directly to the header through the downcomer. Of course, in other embodiments, a circulation pump can also be installed in the downcomer connecting the boiler drum and the header to enhance the driving force of the working fluid circulation, so that the water in the lower part of the drum can flow smoothly to the header through the downcomer.

[0042] like Figure 2As shown, the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is the main steam. The inlet of the desuperheating module is connected to the main steam pipeline to introduce part of the main steam. The introduced part of the main steam passes through the isolation valve and pressure reducing valve in the desuperheating module and enters the desuperheater to mix with the desuperheating water. Then it is sent to the newly added external steam cooler to supplement the heating of the feedwater. The steam outlet of the external steam cooler is then sent to the existing final stage high-pressure heater to heat the feedwater, so as to improve the feedwater temperature of the unit under deep peak shaving conditions. Of course, in other embodiments, the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder can be the main steam of the unit, the steam in the superheater system, the steam in the rear chamber of the high-pressure cylinder regulating stage, or any one of the main steam, the steam in the superheater system, and the steam in the rear chamber of the high-pressure cylinder regulating stage, mixed with the regenerative extraction steam or reheat steam of the unit. This can make full use of the steam of the unit and provides multiple options for the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder. Under the premise that the steam entering the external steam cooler is higher than the existing regenerative extraction steam, the operational flexibility of the unit is improved. Of course, the steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder can also be the main steam of other units, the steam in the superheater system, the steam in the back chamber of the high-pressure cylinder regulating stage, or any one of the main steam, the steam in the superheater system, or the steam in the back chamber of the high-pressure cylinder regulating stage of other units, mixed with the regenerative extraction steam or reheat steam. In this way, the steam of other units can be fully utilized, and while ensuring that the steam entering the external steam cooler is higher than the existing regenerative extraction steam, the operational flexibility of the unit is improved and the thermodynamic cycle of the entire system is optimized.

[0043] The operating system configuration provided by this utility model, under deep peak shaving conditions, taking 20% ​​THA as an example: the feedwater temperature at the boiler inlet can be increased to 75% THA or even 100% THA. With the increase in feedwater temperature, the economizer inlet water temperature increases, leading to an increase in economizer outlet water temperature, and consequently, an increase in economizer outlet flue gas temperature to meet the denitrification inlet flue gas temperature requirements. Furthermore, while increasing the economizer outlet water temperature, a certain feedwater pressure is maintained, ensuring a certain degree of subcooling at the economizer outlet. Furthermore, with the increase in feedwater pressure, the pressure of the steam-water mixture in the steam drum also increases, leading to an increase in the wet saturated steam temperature at the top of the steam drum, and further, an increase in the main steam temperature. Furthermore, with the increase in the ratio of main steam temperature, main steam quantity, and reheat steam quantity, both cold reheat steam and hot reheat steam temperatures are increased, thus avoiding a significant increase in unit energy consumption and effectively improving the unit's operating economy.

[0044] Taking a 300MW subcritical unit with a partial steam inlet in its high-pressure cylinder and a regulating stage as an example, and the unit operating under 20% THA conditions.

[0045] The existing system has the following parameters: main generator load 60MW, current final stage high pressure heater inlet steam pressure and temperature parameters 1.29MPa, 370℃, outlet feedwater pressure and temperature parameters 8.5MPa, 192℃, economizer outlet water temperature 211℃, subcooling 107.3℃, underenthalpy 521kJ / kg, and economizer outlet flue gas temperature 272℃. The denitrification system cannot be put into operation.

[0046] In this embodiment, the main generator load is 60MW. After the addition of an external steam cooler for desuperheating, the inlet steam pressure and temperature parameters of the new final stage high-pressure heater are 3.59MPa and 419℃, and the outlet feedwater pressure and temperature parameters are 10.5MPa and 244℃. The water-side temperature rise of the new external steam cooler is 5℃. The economizer outlet water temperature is 269℃, the subcooling is 45.6℃, the underenthalpy is 250.7kJ / kg, and the economizer outlet flue gas temperature is 336℃. The denitrification system is stably and continuously put into operation, and the unit's operating economy is improved due to the relative increase in feedwater temperature. Simultaneously, the regulation... The inlet and outlet flow rates, pressures, and temperatures of the regulating stage are 212 t / h, 10.1 MPa, and 531℃, and 212 t / h, 2.5 MPa, and 441℃, respectively. The effective enthalpy drop per unit working fluid is 121.7 kJ / kg, corresponding to a power output of 7.2 MW. Compared to the isenthalpic throttling method that simply uses valves without a regulating stage, the regulating stage inlet valve group achieves the same pressure control effect for the main steam while improving the unit's economic efficiency. Furthermore, because the flow rate of each valve in the regulating stage inlet valve group is relatively small, its pressure control of the main steam will be more precise and convenient.

[0047] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A system configuration for running, comprising: A boiler, deaerator system, high-pressure cylinder, existing final-stage high-pressure heater, feedwater pipeline, and steam pipeline are characterized in that the boiler includes an economizer, steam drum, superheater, header, downcomer, and water-cooled wall; the economizer, steam drum, and superheater are connected sequentially by pipelines; water from the lower part of the steam drum flows through the downcomer to the header, is heated by the water-cooled wall, and then returns to the steam drum; the high-pressure cylinder adopts a partial steam inlet method and is equipped with a regulating stage; in the feedwater pipeline, along the feedwater flow direction, a deaerator system, an existing final-stage high-pressure heater, a newly added final-stage high-pressure heater, a newly added external steam cooler, and a newly added external steam cooler are sequentially arranged. The feedwater outlet is connected to the boiler feedwater inlet; the steam pipeline includes a main steam pipeline connecting the boiler steam outlet and the high-pressure cylinder steam inlet, and an extraction steam pipeline connecting the high-pressure cylinder extraction steam inlet and the existing final-stage high-pressure heater inlet; the main steam pipeline is equipped with a regulating stage steam inlet valve group, and the extraction steam pipeline is equipped with an extraction steam isolation valve; the steam-side inlet of the newly added external steam cooler is connected to a desuperheating module, and the inlet of the desuperheating module is connected to steam with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder, and the steam-side outlet of the newly added external steam cooler is connected to the steam inlet of the newly added final-stage high-pressure heater.

2. The operating system configuration as described in claim 1, characterized in that, The cooling module includes an isolation valve, a pressure reducing valve, and a cooler connected in sequence by pipes, with cooling water connected to the cooler.

3. The operating system configuration as described in claim 2, characterized in that, The steam pressure at the steam-side outlet of the newly added external steam cooler is higher than the regenerative extraction steam pressure of the high-pressure cylinder.

4. The operating system configuration as described in claim 3, characterized in that, Inside the boiler, a circulating pump is installed in the downcomer connecting the steam drum and the header.

5. The operating system configuration as described in claim 4, characterized in that, The steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is the main steam of the unit, the steam in the superheater system, the steam in the back chamber of the high-pressure cylinder regulating stage, or a mixture of the main steam, the steam in the superheater system, and the steam in the back chamber of the high-pressure cylinder regulating stage of the unit with the regenerative extraction steam or reheat steam of the unit.

6. The operating system configuration as described in claim 4, characterized in that, The steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is the main steam of the unit, and the inlet of the desuperheating module is connected to the main steam pipeline to introduce part of the main steam.

7. The operating system configuration as described in claim 4, characterized in that, The steam source with a higher pressure level than the regenerative extraction steam of the high-pressure cylinder is a mixture of main steam from other units, steam in the superheater system, steam in the regulating chamber after the high-pressure cylinder, or steam in the main steam, steam in the superheater system, or steam in the regulating chamber after the high-pressure cylinder, and regenerative extraction steam or reheat steam.

8. The operating system configuration as described in claim 1, characterized in that, The regulating stage inlet valve group has four or six valves.

9. The operating system configuration as described in any one of claims 1-8, characterized in that, A throttling component is installed in the feedwater or steam pipeline system from the economizer outlet to the high-pressure cylinder inlet.

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