Thermal power plant electric steam boiler coupling spherical heat storage tank system and peak regulation and frequency modulation method
By coupling a spherical thermal storage tank system with an electric steam boiler in a thermal power plant and using a frequency regulation control module to optimize steam flow and power consumption, the problem of steam storage during load peak shaving in thermal power units has been solved, achieving low-cost and high-efficiency steam energy storage and industrial steam supply stability.
Patent Information
- Application Number
- CN202511738753.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-01-09
AI Technical Summary
During peak load regulation, existing thermal power units cannot achieve large-scale steam storage, and existing heat storage devices are complex and costly, failing to meet the stable steam demand of industrial users.
The design incorporates a spherical thermal storage tank system for coupling an electric steam boiler in a thermal power plant. This system utilizes surplus electricity from the thermal power plant's flexible peak-shaving and frequency regulation to heat water in the electric steam boiler, generating steam. The steam is then stored in the thermal storage tank, and combined with a frequency regulation control module, steam flow and power consumption are optimized to achieve efficient peak-shaving and frequency regulation response.
It has improved the peak-shaving and frequency regulation response capabilities of thermal power units, achieved low-cost steam energy storage, met the steam supply demand throughout the day, and ensured the stability and flexibility of industrial steam supply.
Smart Images
Figure CN121296960A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a system of electric steam boilers coupled with spherical thermal storage tanks in thermal power plants and a method for peak shaving and frequency regulation, belonging to the field of novel energy storage technology. Background Technology
[0002] With the rapid expansion of new energy power generation and increasingly stringent global greenhouse gas emission reduction requirements, the average load factor and utilization hours of thermal power units have continued to decline, and the power grid has even frequently experienced negative electricity prices. Meanwhile, the industrial steam demand in some industrial parks has steadily increased, creating a stark contrast. During periods of negative electricity prices, thermal power units reduce their power generation load for deep peak shaving, causing a decrease in previously extracted industrial steam source parameters, which cannot meet the needs of industrial users. Extracting and storing more steam during high-load periods of thermal power units and supplying it to external users during off-peak periods is a feasible solution. However, steam itself is difficult to store on a large scale; currently, it mainly relies on thermal storage devices for conversion, such as using high-temperature solid thermal storage or molten salt thermal storage materials to heat feedwater to generate superheated steam.
[0003] However, the aforementioned solid or molten salt thermal storage technologies suffer from drawbacks such as system complexity and high investment costs, thus requiring urgent improvement. Summary of the Invention
[0004] To overcome the shortcomings of the prior art, this invention designs a spherical thermal storage tank system coupled with a steam boiler in a thermal power plant and a peak-shaving and frequency regulation method. It utilizes the surplus electricity from the flexible peak-shaving and frequency regulation of thermal power to heat the water in the steam boiler to generate steam, or extracts steam from the steam turbine and sends it to the steam thermal storage spherical tank for thermal energy storage, effectively improving the peak-shaving and frequency regulation response capability of thermal power units.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: Technical Solution 1 A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant includes a thermal power unit. The steam extraction outlet of the thermal power unit is connected to a three-way valve one. The three-way valve one is also connected to a three-way valve two and a regulating valve one. The outlet end of the regulating valve one is connected to a steam thermal storage spherical tank. The power supply outlet of the thermal power unit is electrically connected to an electric steam boiler and a frequency regulation control module. The output end of the electric steam boiler is connected to a regulating valve two, and the output end of the regulating valve two is connected to a steam heat storage spherical tank. The output end of the steam storage spherical tank is connected to an electric superheater, the output end of the electric superheater is connected to a three-way valve, and the output end of the three-way valve is connected to an industrial steam pipeline. The frequency modulation control module is also electrically connected to the regulating valve.
[0006] Furthermore, the electric steam boiler is any one of the following: electrode steam boiler, resistance steam boiler, electric solid thermal storage steam boiler, electric heating molten salt thermal storage steam boiler, and electric heating high-temperature thermal oil steam boiler; the electrode steam boiler is one or a combination of two of the following: jet steam boiler and semi-submerged steam boiler.
[0007] Furthermore, the bottom of the steam storage spherical tank is a liquid saturated water region, and the top of the steam storage spherical tank is a vapor saturated steam region.
[0008] Furthermore, a steam pressure sensor, a steam flow sensor, and a steam temperature sensor are installed at the upper part of the steam storage spherical tank; a water level gauge and a water temperature and pressure monitoring sensor are installed at the lower part of the steam storage spherical tank; and a spherical tank safety detection component is also installed inside the steam storage spherical tank.
[0009] Furthermore, the spherical tank safety detection component includes a spherical tank stress detection device and a safety relief valve.
[0010] Furthermore, steam pressure sensors are installed on each connecting pipe.
[0011] Furthermore, each connecting pipe is equipped with a steam flow meter.
[0012] Furthermore, each connecting pipe is equipped with a steam temperature sensor.
[0013] Technical Solution Two A peak-shaving and frequency regulation method based on the above-mentioned technical solution one, using a thermal power plant electric steam boiler coupled with a spherical thermal storage tank system, includes the following steps: Step S1: Use the frequency modulation control module to control the increase or decrease of the power consumption of the electric steam boiler, or use the frequency modulation control module to control the opening of regulating valve one, thereby controlling the increase or decrease of the flow rate into the steam storage tank, so as to realize the response to the peak-shaving and frequency modulation signal of the thermal power unit.
[0014] Further, step S1 specifically includes: S11: Heat storage period: Saturated steam generated by the electric steam boiler is supplied to the steam heat storage spherical tank for heat storage; Heat release period: Saturated steam generated by the steam heat storage spherical tank is heated to a superheated state by the electric superheater and then supplied to the outside for industrial steam. S12: When a thermal power unit receives a peak-shaving or frequency regulation request from the grid dispatch to reduce the on-grid power, the frequency regulation control module is used to control the electric steam boiler to increase power consumption or the frequency regulation control module is used to control the opening of regulating valve one to increase the steam extraction, thereby reducing the on-grid power and realizing the auxiliary service requirements of thermal power unit to quickly respond to flexible peak-shaving, frequency regulation and load reduction. S13: When a thermal power unit receives a request from the grid dispatching authority to increase the on-grid power generation for peak shaving or frequency regulation, the frequency regulation control module is used to control the electric steam boiler to reduce power consumption, or the frequency regulation control module is used to control the opening of regulating valve one to reduce the amount of steam extracted, thereby increasing the on-grid power generation and realizing the auxiliary service needs of thermal power unit for rapid response, flexible peak shaving, frequency regulation and load reduction.
[0015] Compared with the prior art, the present invention has the following features and beneficial effects: This invention utilizes surplus electricity from thermal power plants for peak shaving and frequency regulation to heat water in electric steam boilers to generate steam, or extracts steam from steam turbines and sends it to steam storage tanks for thermal energy storage. This effectively improves the peak shaving and frequency regulation response capability of thermal power units, thereby enabling low-cost thermal energy storage of steam and meeting the 24-hour steam supply needs of the region. Attached Figure Description
[0016] Figure 1 This is a system connection diagram of the present invention.
[0017] The attached diagrams are labeled as follows: 1. Thermal power unit; 2. Electric steam boiler; 3. Steam storage spherical tank; 4. Electric superheater; 5. Frequency control module; 100. Three-way valve one; 200. Three-way valve two; 300. Regulating valve one; 400. Regulating valve two. Detailed Implementation
[0018] The present invention will now be described in more detail with reference to the embodiments.
[0019] Example 1 Please see Figure 1 The thermal power plant electric steam boiler coupled spherical heat storage tank system of this embodiment includes thermal power unit 1. The steam extraction outlet of thermal power unit 1 is connected to a three-way valve 100. The three-way valve 100 is also connected to a three-way valve 200 and a regulating valve 300. The outlet end of the regulating valve 300 is connected to a steam heat storage spherical tank 3.
[0020] Among them, the power supply outlet of thermal power unit 1 is electrically connected to electric steam boiler 2 and frequency regulation control module 5. The output end of electric steam boiler 2 is connected to regulating valve 400, and the output end of regulating valve 400 is connected to steam heat storage spherical tank 3.
[0021] The output end of the steam storage spherical tank 3 is connected to an electric superheater 4. The output end of the electric superheater 4 is connected to a three-way valve 200, and the output end of the three-way valve 200 is connected to an industrial steam pipeline network.
[0022] The frequency modulation control module 5 is also electrically connected to the regulating valve 300.
[0023] As can be seen from the above description, the frequency modulation control module 5 can control the power consumption of the electric steam boiler 2. At the same time, the frequency modulation control module 5 can also control the opening degree of the regulating valve 300, thereby controlling the increase or decrease of the flow rate into the steam heat storage tank 3, and thus realize the response to the peak-shaving and frequency modulation signal of the thermal power unit 1.
[0024] Furthermore, the electric steam boiler 2 is any one of the following: electrode steam boiler, resistance steam boiler, electric solid thermal storage steam boiler, electric heating molten salt thermal storage steam boiler, and electric heating high-temperature thermal oil steam boiler; the electrode steam boiler is one or a combination of two of the following: jet steam boiler and semi-submerged steam boiler.
[0025] Furthermore, the bottom of the steam storage spherical tank 3 is a liquid saturated water region, and the top of the steam storage spherical tank 3 is a gaseous saturated steam region. Through the natural stratification of the liquid saturated water at the bottom and the saturated steam at the top, the steam storage spherical tank 3 stores energy and maintains pressure during heat storage. During heat release, the saturated water at the bottom flashes to continuously and stably output high-quality steam, which significantly improves the system's heat storage density and steam supply response speed, ensuring the stable and efficient operation of the thermal power unit 1's frequency regulation and industrial steam supply.
[0026] Furthermore, the upper part of the steam storage spherical tank 3 is equipped with a steam pressure sensor, a steam flow sensor, and a steam temperature sensor; the lower part of the steam storage spherical tank 3 is equipped with a water level gauge and a water temperature and pressure monitoring sensor; and the steam storage spherical tank 3 is also equipped with a spherical tank safety detection component.
[0027] The various sensors and safety components installed at the upper and lower ends of the steam storage spherical tank 3 can monitor key parameters such as pressure and temperature inside the tank in real time, providing accurate data support for the frequency regulation control module 5, and realizing precise control of regulating valve 1 300, regulating valve 2 400 and electric superheater 4, thereby ensuring the safety and stability of the heat storage and release process, and optimizing the system frequency regulation and steam supply response efficiency.
[0028] Furthermore, the spherical tank safety detection component includes a spherical tank stress detection device and a safety relief valve, which can monitor the health status of the tank structure in real time and automatically release pressure when overpressure occurs. This dual protection mechanism significantly improves the inherent safety of the system under frequent heat storage and release conditions, ensuring stable and reliable frequency regulation and steam supply processes.
[0029] Furthermore, each connecting pipe is equipped with a steam pressure sensor, a steam flow meter, and a steam temperature sensor, providing real-time data for the entire process to the frequency modulation control module 5. This enables precise closed-loop control of actuators such as three-way valves and regulating valves, thereby optimizing the steam storage and release process and ensuring the stability of the system's frequency modulation response speed and steam supply quality.
[0030] Example 2 The peak-shaving and frequency regulation method for a thermal power plant's electric steam boiler coupled with a spherical thermal storage tank system, based on the above-described embodiment one, includes the following steps: Step S1: Use the frequency modulation control module 5 to control the increase or decrease of the power consumption of the electric steam boiler 2, or use the frequency modulation control module 5 to control the opening of the regulating valve 300, thereby controlling the increase or decrease of the flow rate into the steam heat storage tank 3, so as to realize the response to the peak regulation and frequency modulation signal of the thermal power unit 1.
[0031] Specifically, step S1 includes: S11: Heat storage period: The saturated steam generated by the electric steam boiler 2 is supplied to the steam heat storage spherical tank 3 for heat storage; Heat release period: The saturated steam generated by the steam heat storage spherical tank 3 is heated to a superheated state by the electric superheater 4 and then supplied to the outside for industrial steam. S12: When thermal power unit 1 receives a peak shaving or frequency regulation request from the grid dispatch to reduce the on-grid power, the frequency regulation control module 5 is used to control the electric steam boiler 2 to increase the power consumption, or the frequency regulation control module 5 is used to control the opening of regulating valve 300 to increase the steam extraction, thereby reducing the on-grid power and realizing the auxiliary service requirements of thermal power unit 1 for rapid response, flexible peak shaving, frequency regulation and load reduction. S13: When thermal power unit 1 receives a peak shaving or frequency regulation request from the grid dispatch to increase the on-grid power, the frequency regulation control module 5 is used to control the electric steam boiler 2 to reduce power consumption, or the frequency regulation control module 5 is used to control the opening of regulating valve 300 to reduce the steam extraction, thereby increasing the on-grid power and realizing the auxiliary service needs of thermal power unit 1 for rapid response, flexible peak shaving, frequency regulation and load reduction.
[0032] In the description of this invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.
[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0034] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
Claims
1. A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant, characterized in that: The unit includes a thermal power unit (1), the steam extraction outlet of which is connected to a three-way valve one (100), the three-way valve one (100) is also connected to a three-way valve two (200) and a regulating valve one (300), and the outlet end of the regulating valve one (300) is connected to a steam storage spherical tank (3). The power supply outlet of the thermal power unit (1) is electrically connected to an electric steam boiler (2) and a frequency control module (5). The output end of the electric steam boiler (2) is connected to a regulating valve (400), and the output end of the regulating valve (400) is connected to a steam storage spherical tank (3). The output end of the steam storage spherical tank (3) is connected to an electric superheater (4), the output end of the electric superheater (4) is connected to a three-way valve (200), and the output end of the three-way valve (200) is connected to an industrial steam pipeline network. The frequency modulation control module (5) is also electrically connected to the regulating valve (300).
2. The spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 1, characterized in that: The electric steam boiler (2) is any one of the following: electrode steam boiler, resistance steam boiler, electric solid thermal storage steam boiler, electric heating molten salt thermal storage steam boiler, and electric heating high-temperature thermal oil steam boiler; the electrode steam boiler is one or a combination of two of the following: jet steam boiler and semi-submerged steam boiler.
3. The spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 1, characterized in that: The bottom of the steam storage spherical tank (3) is a liquid saturated water region, and the top of the steam storage spherical tank (3) is a vapor saturated steam region.
4. A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 3, characterized in that: The upper part of the steam storage spherical tank (3) is equipped with a steam pressure sensor, a steam flow sensor and a steam temperature sensor; the lower part of the steam storage spherical tank (3) is equipped with a water level gauge and a water temperature and pressure monitoring sensor; the steam storage spherical tank (3) is also equipped with a spherical tank safety detection component.
5. A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 4, characterized in that: The spherical tank safety detection component includes a spherical tank stress detection device and a safety relief valve.
6. A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 1, characterized in that: Each connecting pipe is equipped with a steam pressure sensor.
7. A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 1, characterized in that: Each connecting pipe is equipped with a steam flow meter.
8. A spherical thermal storage tank system coupled to an electric steam boiler in a thermal power plant according to claim 1, characterized in that: Each connecting pipe is equipped with a steam temperature sensor.
9. A peak-shaving and frequency regulation method for a thermal power plant electric steam boiler coupled with a spherical thermal storage tank system according to any one of claims 1-8, characterized in that: Includes the following steps: Step S1: Use the frequency control module (5) to control the increase or decrease of the power consumption of the electric steam boiler (2) or use the frequency control module (5) to control the opening of the regulating valve (300) and thus control the increase or decrease of the flow rate into the steam storage tank (3), so as to realize the response to the peak-shaving and frequency regulation signal of the thermal power unit (1).
10. The peak-shaving and frequency regulation method for a thermal power plant electric steam boiler coupled with a spherical thermal storage tank system according to claim 9, characterized in that: Step S1 specifically includes: S11: Heat storage period: Saturated steam generated by electric steam boiler (2) is supplied to steam heat storage sphere tank (3) for heat storage; Heat release period: Saturated steam generated by the steam heat storage sphere tank (3) is heated to a superheated state by the electric superheater (4) and then supplied to the outside for industrial steam; S12: When the thermal power unit (1) receives the grid dispatch to reduce the on-grid power generation, it uses the frequency control module (5) to control the electric steam boiler (2) to increase the power consumption or uses the frequency control module (5) to control the opening of regulating valve 1 (300) to increase the steam extraction, thereby reducing the on-grid power generation and realizing the auxiliary service needs of the thermal power unit (1) to quickly respond to the flexible peak shaving, frequency regulation and load reduction. S13: When the thermal power unit (1) receives a peak-shaving or frequency regulation demand from the grid dispatch to increase the on-grid power, the frequency regulation control module (5) controls the electric steam boiler (2) to reduce power consumption or the frequency regulation control module (5) controls the opening of regulating valve 1 (300) to reduce the amount of steam extracted, thereby increasing the on-grid power and realizing the auxiliary service demand of the thermal power unit (1) to quickly respond to the flexible peak-shaving, frequency regulation and load reduction.