Energy storage peak regulation system

Abstract

The invention relates to the technical field of coal-fired power plant deep peak regulation and energy storage, in particular to an energy storage peak regulation system which comprises a first-stage energy storage pipeline, a steam conveying pipeline and a controller. The first-stage energy storage pipeline comprises a heat collecting device, a first-stage energy storage device, a first-stage circulating fan and a first-stage heat exchanger which are sequentially connected through pipelines; gas circularly flows in the first-stage energy storage pipeline, the heat collection device is used for absorbing solar energy and converting the absorbed solar energy into heat energy so as to heat the gas flowing through the heat collection device, a solid heat storage material is arranged in the first-stage energy storage device, and the first-stage heat exchanger is used for exchanging heat with condensed water flowing out of the output end of the generator. The solid heat storage material is adopted to replace fused salt, so that the problems that due to low temperature, the fused salt crystallizes, the system operation is not smooth, and the operation efficiency is reduced are solved. And meanwhile, solar energy is utilized to heat the solid heat storage material, so that factory resources are fully utilized, the system operation energy consumption is reduced, and the operation cost is saved.

Description

Technical Field

[0001] This application relates to the field of deep peak shaving and energy storage technology for coal-fired power plants, specifically to an energy storage peak shaving system. Background Technology

[0002] With the large-scale grid connection of new energy power generation, the power system faces severe challenges in the efficient absorption and safe and stable operation of new energy sources such as wind and solar power, due to the volatility and randomness of new energy resources, as well as the weak resistance and low support of power generation equipment. There is an urgent need for a high proportion of flexible power sources and energy storage capacity to improve the power structure and ensure grid security.

[0003] Existing technologies primarily involve deep peak-shaving retrofits of main equipment in coal-fired power plants, mostly employing molten salt thermal storage peak-shaving technology. For example, Chinese patent application CN119393203A discloses a steam-molten salt coupled thermal storage and release peak-shaving system and method, proposing a molten salt and steam coupled thermal storage and release scheme. This scheme achieves thermal storage and release of molten salt by diverting main boiler steam into a thermal storage and exchange system, combined with condensate pipelines and a heat release and exchange system. The stored heat is then used to heat condensate to produce steam, which participates in the turbine's work. This scheme has certain advantages in terms of energy storage capacity and peak-shaving response. However, due to the use of molten salt as the thermal storage medium, the overall system cost is high, and the molten salt's tendency to crystallize at low temperatures increases the complexity of operation and control, limiting its widespread adoption in scenarios with high economic requirements. Furthermore, this system does not effectively utilize renewable energy sources such as solar energy, failing to fully utilize plant resources. Summary of the Invention

[0004] The purpose of this application is to provide an energy storage and peak shaving system that uses solid thermal storage materials instead of molten salt to avoid the complex system operation and control problems caused by molten salt crystallization, while using solar energy to heat the solid energy storage materials to make full use of plant resources.

[0005] To achieve the above objectives, this application employs an energy storage peak-shaving system, comprising: A primary energy storage pipeline includes a solar collector, a primary energy storage device, a primary circulating fan, and a primary heat exchanger connected sequentially via a pipeline. Gas circulates inside the primary energy storage pipeline. The solar collector absorbs solar energy and converts it into heat energy to heat the gas flowing through it. The primary energy storage device contains solid heat storage material. The primary heat exchanger is connected to the solar collector via a first pipeline. The input end of the primary heat exchanger is connected to the output end of a generator set, and the primary heat exchanger is used to exchange heat with the condensate flowing out of the generator set's output end. A steam transmission pipeline is provided, and a steam-water separator is installed on the steam transmission pipeline. The input end of the steam-water separator is connected to the output end of the first-stage heat exchanger through a second pipeline. The steam-water separator is used to separate the water and steam output from the first-stage heat exchanger. The output end of the steam-water separator is connected to a steam turbine or heating header through a third pipeline to transport the separated steam to the steam turbine or heating header. A first valve is provided on the third pipeline. The controller is electrically connected to the heat collection device, the primary energy storage device, the primary circulating fan, the primary heat exchanger, and the steam-water separator.

[0006] As a preferred technical solution, the energy storage peak-shaving system further includes: a secondary energy storage pipeline, which includes a secondary energy storage device, a secondary circulating fan, and a secondary heat exchanger connected in sequence through the pipeline, and gas circulates inside the secondary energy storage pipeline. The secondary energy storage device is equipped with solid heat storage material and an electric heater, and the electric heater is used to heat the solid heat storage material. The output end of the steam-water separator is connected to the input end of the secondary heat exchanger through a fourth pipeline, and the output end of the secondary heat exchanger is connected to a steam turbine or a heating header through a fifth pipeline, and a second valve is provided on the fifth pipeline. The controller is electrically connected to the secondary energy storage device, the secondary circulating fan, and the electric heater, respectively.

[0007] As a preferred technical solution, a first temperature detector is also provided on the steam delivery pipeline. The first temperature detector is used to detect the temperature of the steam output from the output end of the first-stage heat exchanger. The controller is electrically connected to the first temperature detector, and the controller is configured to: Obtain the actual steam temperature t1 detected by the first temperature detector; Compare the actual steam temperature t1 with the preset steam temperature t2; When t1 > t2, open the first valve and close the second valve to deliver steam to the steam turbine or heating header; When t1≤t2, the second valve is opened and the first valve is closed, and the steam is delivered to the secondary heat exchanger for heat exchange.

[0008] As a preferred technical solution, the solid heat storage material is concrete or inorganic silicate particles.

[0009] As a preferred technical solution, both the primary energy storage pipeline and the secondary energy storage pipeline are provided with gas replenishment ports. Each gas replenishment port is connected to a gas storage tank through an eighth pipeline, and a third valve is provided on the eighth pipeline.

[0010] As a preferred technical solution, both the primary energy storage pipeline and the secondary energy storage pipeline are equipped with pressure detectors. The two pressure detectors are used to detect the gas pressure in the primary and secondary energy storage pipelines, respectively. The two pressure detectors are electrically connected to the controller, which is further configured to: Obtain the actual gas pressure P1 detected by the pressure detector; Compare the actual gas pressure P1 with the preset gas pressure P2; When P1 < P2, the third valve on the primary energy storage pipeline and / or the secondary energy storage pipeline is opened to connect the gas supply port on the primary energy storage pipeline and / or the secondary energy storage pipeline with the gas storage tank. When P1≥P2, close the third valve on the primary energy storage pipeline and / or the secondary energy storage pipeline.

[0011] As a preferred technical solution, a fourth valve is provided on the first pipeline; The energy storage and peak-shaving system further includes a gas pressurization pipeline, which includes a condenser and a circulating pump connected in sequence through a pipeline. The condenser is connected to the first-stage heat exchanger through a sixth pipeline. A fifth valve is provided on the sixth pipeline. One end of the first pipeline is connected to the sixth pipeline, and the other end is connected to the heat collection device. The circulating pump is connected to the heat collection device through a seventh pipeline.

[0012] As a preferred technical solution, a second temperature detector is also provided on the sixth pipeline. The second temperature detector is located on the sixth pipeline and is used to detect the temperature of the gas after heat exchange with the first-stage heat exchanger. The controller is electrically connected to the second temperature detector, and the controller is further configured to: Obtain the actual gas temperature t3 detected by the second temperature detector; Compare the actual gas temperature t3 with the preset gas temperature t4; When t3 > t4, the fourth valve is opened to connect the first pipeline, and the fifth valve is closed. When t3≤t4, the fourth valve is closed and the fifth valve is opened to deliver the gas to the condenser for cooling to a liquid state. The cooled liquid is then delivered to the circulating pump for pressurization into gas, and finally delivered to the heat collection device.

[0013] As a preferred technical solution, the heat collection device is a trough-type heat collector.

[0014] As a preferred technical solution, the energy storage peak-shaving system further includes: a water pump, the two ends of which are connected to the steam-water separator and the first-stage heat exchanger respectively through pipelines. The water pump is used to pump the liquid in the steam-water separator to the first-stage heat exchanger for heat exchange, and the water pump is electrically connected to the controller.

[0015] The energy storage and peak-shaving system provided by the above technical solution has the following advantages compared with existing technologies: it uses solid thermal storage materials instead of molten salt to avoid the problem of molten salt crystallization due to low temperatures, which would cause the system to malfunction and reduce operating efficiency. At the same time, it uses solar energy to heat the solid thermal storage materials, making full use of plant resources while reducing system operating energy consumption and saving operating costs.

[0016] Furthermore, by setting up primary and secondary energy storage pipelines, the primary or secondary energy storage pipelines can be controlled to operate independently or simultaneously to supply steam, based on the actual steam temperature requirements of the steam turbine or heating header, thereby further reducing energy consumption.

[0017] In addition, to prevent the supercritical carbon dioxide in the energy storage pipeline from liquefying at low temperatures and adversely affecting the operating efficiency, this application also sets up a gas pressurization pipeline to completely liquefy the partially liquefied supercritical carbon dioxide before pressurizing and gasifying it, and then re-transporting it to the heat collection device for heating, thus ensuring the stability of the operating efficiency. Attached Figure Description

[0018] The present application will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present application. Furthermore, unless specifically indicated, the drawings are intended only to conceptually represent the composition or structure of the described objects and may contain exaggerated representations, and the drawings are not necessarily drawn to scale.

[0019] Figure 1 This is a schematic diagram of the energy storage and peak-shaving system of this application; The system includes: 1. Primary energy storage pipeline; 11. Thermal collector; 12. Primary energy storage device; 121. Electric heater; 122. Solid thermal storage material; 13. Primary circulating fan; 14. Primary heat exchanger; 15. Gas supply port; 16. Third valve; 17. Pressure detector; 18. Fourth valve; 19. First pipeline; 2. Steam delivery pipeline; 21. Steam-water separator; 22. First valve; 23. First temperature detector; 24. Second pipeline; 25. Third... Pipeline; 26. Fourth Pipeline; 3. Secondary Energy Storage Pipeline; 31. Secondary Energy Storage Device; 32. Secondary Circulating Fan; 33. Secondary Heat Exchanger; 34. Second Valve; 35. Fifth Pipeline; 36. Eighth Pipeline; 4. Gas Storage Tank; 5. Gas Pressurization Pipeline; 51. Condenser; 52. Circulating Pump; 53. Second Temperature Detector; 54. Fifth Valve; 55. Sixth Pipeline; 57. Seventh Pipeline; 6. Water Pump; 7. Generator Set; 8. Steam Turbine or Heating Header. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0021] In the description of this application, it should be understood that the terms "front," "rear," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, in the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Please see Figure 1 An energy storage and peak shaving system provided in this application includes: a primary energy storage pipeline 1, a steam transmission pipeline 2, and a controller (not shown in the attached drawings). The primary energy storage pipeline 1 includes a solar collector 11, a primary energy storage device 12, a primary circulating fan 13, and a primary heat exchanger 14 connected in sequence through a pipeline. Gas circulates inside the primary energy storage pipeline 1. The solar collector 11 is used to absorb solar energy and convert the absorbed solar energy into heat energy to heat the gas flowing through the solar collector 11. The primary energy storage device 12 is equipped with solid heat storage material 122. The primary heat exchanger 14 is connected to the solar collector 11 through a first pipeline 19. The input end of the primary heat exchanger 14 is connected to the output end of the generator set 7, and the primary heat exchanger 14 is used to exchange heat with the condensate flowing out of the output end of the generator set 7. A steam-water separator 21 is installed on the steam transmission pipeline 2. The input end of the steam-water separator 21 is connected to the output end of the first-stage heat exchanger 14 through the second pipeline 24. The steam-water separator 21 is used to separate the water and steam output from the first-stage heat exchanger 14. The output end of the steam-water separator 21 is connected to the steam turbine or heating header 8 through the third pipeline 25 to transport the separated steam to the steam turbine or heating header 8. A first valve 22 is installed on the third pipeline 25. The controller is electrically connected to the solar collector 11, the primary energy storage device 12, the primary circulating fan 13, the primary heat exchanger 14, and the steam-water separator 21.

[0023] In this embodiment, solid heat storage material 122 is used to replace molten salt to avoid the problem of molten salt crystallization due to low temperature, which would cause system malfunction and reduced operating efficiency. Simultaneously, solar energy is used to heat the solid heat storage material, making full use of plant resources while reducing system energy consumption and saving operating costs. During operation, the primary circulating fan 13 is first started to drive the gas to circulate within the primary energy storage pipeline 1. The controller controls and starts the heat collection device 11 to absorb solar energy and convert it into heat energy, heating the gas flowing through the heat collection device 11. Specifically, the heat collection device 11 can be a heat pipe type vacuum tube solar collector, equipped with heat collection tubes connected to the primary energy storage pipeline 1. When sunlight shines on the heat collection tubes, the heat collection tubes receive solar radiation energy and heat the gas flowing inside the heat collection tubes through heat transfer. The heated gas flows to the primary energy storage device 12 and exchanges heat with the solid thermal storage material 122 inside the device, allowing the thermal energy to be stored in the material. During this time, the primary heat exchanger 14 is not in operation. When high-temperature steam needs to be supplied to the turbine or heating header 8, the controller controls and starts the primary heat exchanger 14 and the primary circulating fan 13. The high-temperature gas, after heat exchange with the solid thermal storage material 122, then exchanges heat with the condensate in the primary heat exchanger 14, decomposing the condensate into water and steam. The water and steam flow together to the steam-water separator 21 for separation. The controller controls the opening of the first valve 22, and the separated high-temperature steam is transported to the turbine or heating header 8 through the third pipeline 25 for subsequent operation.

[0024] It is worth noting that in this embodiment, an electric heater 121 is also provided in the primary energy storage device 12 so that when the solar energy intensity is low and the heat collection device 11 cannot heat the circulating gas to the specified temperature, the solid heat storage material 122 in the primary energy storage device 12 can be supplemented with heating to ensure that the solid heat storage material 122 stores enough heat to maintain the stable operation of the system.

[0025] In some embodiments, the energy storage peak-shaving system further includes: a secondary energy storage pipeline 3, which includes a secondary energy storage device 31, a secondary circulating fan 32, and a secondary heat exchanger 33 connected in sequence via pipelines, and gas circulates inside the secondary energy storage pipeline 3. The secondary energy storage device 31 is equipped with a solid heat storage material 122 and an electric heater 121. The electric heater 121 is used to heat the solid heat storage material 122. The output end of the steam-water separator 21 is connected to the input end of the secondary heat exchanger 33 via a fourth pipeline 26. The output end of the secondary heat exchanger 33 is connected to a steam turbine or heating header 8 via a fifth pipeline 35, and a second valve 34 is provided on the fifth pipeline 35. The controller is electrically connected to the secondary energy storage device 31, the secondary circulating fan 32, and the electric heater 121 respectively.

[0026] In this embodiment, the secondary energy storage device 31 uses electric heating to heat the solid thermal storage material 122 to store thermal energy. When the temperature of the steam output from the primary heat exchanger 14 does not meet the actual requirements of the turbine or heating header 8, the secondary energy storage pipeline 3 is opened. The heat stored in the secondary energy storage device 31 is used to heat the gas in the secondary energy storage pipeline 3, and the heated high-temperature gas exchanges heat with the steam output from the primary heat exchanger 14 in the secondary heat exchanger 33, further heating the steam to a specified temperature. Then, the second valve 34 is opened, and the heated steam is transported to the turbine or heating header 8 through the fifth pipeline 35 to participate in subsequent operations. In addition, when the primary energy storage pipeline 1 is under maintenance or damaged, the secondary energy storage pipeline 3 can be started independently to complete the high-temperature steam supply, avoiding downtime.

[0027] It is worth noting that in this embodiment, supercritical carbon dioxide is preferably used instead of air as the circulating gas in the primary energy storage pipeline 1 or the secondary energy storage pipeline 3. On the one hand, supercritical carbon dioxide has stable physical properties and can operate efficiently at higher temperatures. Its circulation efficiency is superior to traditional air circulation, and the compression power consumption during circulation is also less, which helps improve system operating efficiency. On the other hand, energy storage and peak-shaving systems typically use metal pipelines as gas circulation pipelines, while carbon dioxide has stable chemical properties and low corrosiveness to metal materials at high temperatures, which helps extend the service life of metal pipelines, improve the reliability and safety of system operation, and reduce maintenance and replacement costs.

[0028] In some embodiments, a first temperature detector 23 is also provided on the steam delivery pipeline 2. The first temperature detector 23 is used to detect the temperature of the steam output from the output end of the first-stage heat exchanger 14. The controller is electrically connected to the first temperature detector 23, and the controller is configured to: Obtain the actual steam temperature t1 detected by the first temperature detector 23; Compare the actual steam temperature t1 with the preset steam temperature t2; When t1 > t2, the first valve 22 is opened and the second valve 34 is closed to deliver steam to the steam turbine or heating header 8; When t1≤t2, the second valve 34 is opened and the first valve 22 is closed, so that the steam is delivered to the secondary heat exchanger 33 for heat exchange.

[0029] If the same solid thermal storage material 122 is used for both the primary energy storage device 12 and the secondary energy storage device 31, the cost will be high and it will not be economical. Therefore, based on the heating and cooling section parameters, in some embodiments, the inventors have chosen concrete as the solid thermal storage material 122 in the primary energy storage device 12 and inorganic silicate particles as the solid thermal storage material 122 in the secondary energy storage device 31. This ensures that the thermal storage temperature of the primary energy storage device 12 is 200-400℃, meeting the low-temperature steam requirements for the operation of the steam turbine or heating header 8; and the thermal storage temperature of the secondary energy storage device 31 is approximately 1000℃, meeting the high-temperature steam requirements for the operation of the steam turbine or heating header 8. The primary energy storage device 12 and the secondary energy storage device 31 can be started according to the actual steam temperature requirements, or both can be started simultaneously, to better adapt to the actual needs of the system, reduce energy consumption, and improve system operating efficiency.

[0030] In some embodiments, both the primary energy storage pipeline 1 and the secondary energy storage pipeline 3 are provided with gas supply ports 15. Each gas supply port 15 is connected to a gas storage tank 4 via an eighth pipeline 36, and a third valve 16 is provided on the eighth pipeline 36. The gas storage tank 4 is used to supply gas to the primary energy storage pipeline 1 and the secondary energy storage pipeline 3, and the gas flow rate is controlled by the third valve 16. Furthermore, in some embodiments, both the primary energy storage pipeline 1 and the secondary energy storage pipeline 3 are provided with pressure detectors 17. Two pressure detectors 17 are used to detect the gas pressure on the primary energy storage pipeline 1 and the secondary energy storage pipeline 3, respectively. Both pressure detectors 17 are electrically connected to a controller, which is further configured to: Obtain the actual gas pressure P1 detected by the pressure detector 17; Compare the actual gas pressure P1 with the preset gas pressure P2; When P1 < P2, open the third valve 16 on the primary energy storage pipeline 1 and / or the secondary energy storage pipeline 3 to connect the gas replenishment port 15 on the primary energy storage pipeline 1 and / or the secondary energy storage pipeline 3 with the gas storage tank 4.

[0031] In this embodiment, the gas pressure on the primary energy storage pipeline 1 and the secondary energy storage pipeline 3 is monitored in real time by the pressure detector 17. When the gas pressure is insufficient, the controller promptly controls the third valve 16 on the primary energy storage pipeline 1 and / or the secondary energy storage pipeline 3 to open, so that the gas in the gas storage tank 4 enters the primary energy storage pipeline 1 and / or the secondary energy storage pipeline 3 through the gas replenishment port 15 on the primary energy storage pipeline 1 and / or the secondary energy storage pipeline 3 to participate in circulation, ensuring stable system operation and guaranteeing system operating efficiency.

[0032] When the solid heat storage material 122 has completed heat exchange with the circulating gas, and the heat collection device 11 is not restarted to heat the circulating gas or the electric heater 121 is not restarted to heat the solid heat storage material 122, the temperature in the primary energy storage pipeline 1 decreases, and the supercritical carbon dioxide will liquefy due to low temperature, affecting the circulation efficiency. Therefore, in some embodiments, a fourth valve 18 is provided on the first pipeline 19; the energy storage peak-shaving system also includes: a gas pressurization pipeline 5, which includes a condenser 51 and a circulating pump 52 connected in sequence by pipelines. The condenser 51 is connected to the primary heat exchanger 14 through a sixth pipeline 55. A fifth valve 54 is provided on the sixth pipeline 55, and one end of the first pipeline is connected to the sixth pipeline 55, and the other end is connected to the heat collection device 11. The circulating pump 52 is connected to the heat collection device 11 through a seventh pipeline 56. The supercritical carbon dioxide that has been liquefied or partially liquefied is cooled and liquefied through the gas pressurization pipeline 5. Then the liquefied carbon dioxide is repressurized and turned into gaseous carbon dioxide and returned to the pipeline, thereby ensuring the stability of the circulation efficiency.

[0033] To better monitor the liquefaction of the circulating gas and handle the liquefied gas in a timely manner, in some embodiments, a second temperature detector 53 is also provided on the sixth pipeline 55. The second temperature detector 53 is located on the sixth pipeline 55 and is used to detect the temperature of the gas after heat exchange with the first-stage heat exchanger 14. The controller is electrically connected to the second temperature detector 53, and the controller is further configured to: Obtain the actual gas temperature t3 detected by the second temperature detector 53; Compare the actual gas temperature t3 with the preset gas temperature t4; When t3 > t4, the fourth valve 18 is opened to connect the first pipeline 19, and the fifth valve 54 is closed. When t3≤t4, the fourth valve 18 is closed and the fifth valve 54 is opened to deliver the gas to the condenser 51 for cooling to a liquid state. The cooled liquid is then delivered to the circulating pump 52 for pressurization into gas, and then the gas is delivered to the heat collection device 11.

[0034] In some embodiments, the solar collector 11 is a trough solar collector. The trough solar collector converts solar energy into thermal energy through focusing, reflection, and absorption processes, raising the internal heat exchange medium to a certain temperature to meet different heating requirements. Specifically, the trough solar collector includes a tracking device, a reflector, and a heat collection tube. The tracking device drives the reflector to rotate according to the angle of incidence of the sun, ensuring that sunlight shines perpendicularly onto the surface of the reflector. The heat collection tube is connected to the primary energy storage pipeline 1. When sunlight strikes the Earth's surface and shines on the reflector, the reflector focuses the received sunlight onto the surface of the heat collection tube. Thus, the heat collection tube receives solar radiation energy with a high heat flux density. Through heat transfer with the gas inside the heat collection tube, the gas flowing inside the heat collection tube is heated, thereby providing a heat source for heating the solid thermal storage material 122. Parabolic trough solar collectors adopt a modular design, which is easy to replicate on a large scale, and the efficiency does not decrease with the expansion of scale. They are highly adaptable to the site, and the number of modules can be selected according to the actual site, avoiding occupying too much space and affecting the layout and normal operation of other equipment.

[0035] The water separated by the steam-water separator 21 is hot water. Utilizing this hot water can reduce energy consumption and increase the economic efficiency of system operation. In some embodiments, the energy storage and peak-shaving system further includes a water pump 6. The two ends of the water pump 6 are connected to the steam-water separator 21 and the primary heat exchanger 14 respectively via pipelines. The water pump 6 is used to pump the liquid in the steam-water separator 21 to the primary heat exchanger 14 for heat exchange, and the water pump 6 is electrically connected to the controller. It is worth noting that this embodiment is equipped with a water level gauge in the steam-water separator 21. When the water level reaches a set value, the controller controls the water pump 6 to start, delivering the hot water separated by the steam-water separator 21 to the primary heat exchanger 14 as water replenishment. This water itself carries a high heat value, and after exchanging heat with the high-temperature gas in the primary heat exchanger 14, it can quickly turn into steam, greatly reducing heat waste and further improving the thermal efficiency of the entire system.

[0036] In summary, the energy storage and peak-shaving system provided in this embodiment uses solid thermal storage material 122 to replace molten salt, thus avoiding the problem of molten salt crystallization due to low temperatures, which could lead to system malfunctions and reduced operating efficiency. Simultaneously, solar energy is used to heat the solid thermal storage material, fully utilizing plant resources while reducing system energy consumption and saving operating costs. Furthermore, by setting up a primary energy storage pipeline 1 and a secondary energy storage pipeline 3, the system can control the operation of either the primary energy storage pipeline 1 or the secondary energy storage pipeline 3 independently, or both, to supply steam simultaneously, based on the actual steam temperature requirements of the steam turbine or heating header 8, further reducing energy consumption. In addition, to prevent the supercritical carbon dioxide in the primary energy storage pipeline 1 from liquefying at low temperatures and adversely affecting operating efficiency, this application also includes a gas pressurization pipeline 5 to completely liquefy any partially liquefied supercritical carbon dioxide before pressurizing and vaporizing it, then re-transporting it to the heat collection device 11 for heating, ensuring stable operating efficiency.

[0037] This specification discloses the present application with reference to the accompanying drawings and also enables those skilled in the art to implement the application, including making and using any device or system, employing suitable materials, and using any combination of methods. The scope of this application is defined by the claimed technical solution and includes other instances that would occur to those skilled in the art. Such other instances shall be considered to fall within the scope of protection defined by the claimed technical solution, provided that they include structural elements that are not different from the literal language of the claimed technical solution, or contain equivalent structural elements that are not substantially different from the literal language of the claimed technical solution.

Claims

1. An energy storage and peak-shaving system, characterized in that, include: A primary energy storage pipeline includes a solar collector, a primary energy storage device, a primary circulating fan, and a primary heat exchanger connected sequentially via a pipeline. Gas circulates within the primary energy storage pipeline. The solar collector absorbs solar energy and converts it into heat energy to heat the gas flowing through it. The primary energy storage device contains solid heat storage material. The primary heat exchanger is connected to the solar collector via a first pipeline. The input end of the primary heat exchanger is connected to the output end of a generator set, and the primary heat exchanger is used to exchange heat with the condensate flowing out of the generator set's output end. A steam transmission pipeline is provided, and a steam-water separator is installed on the steam transmission pipeline. The input end of the steam-water separator is connected to the output end of the first-stage heat exchanger through a second pipeline. The steam-water separator is used to separate the water and steam output from the first-stage heat exchanger. The output end of the steam-water separator is connected to a steam turbine or heating header through a third pipeline to transport the separated steam to the steam turbine or heating header. A first valve is provided on the third pipeline. The controller is electrically connected to the heat collection device, the primary energy storage device, the primary circulating fan, the primary heat exchanger, and the steam-water separator.

2. The energy storage and peak-shaving system as described in claim 1, characterized in that, Also includes: A secondary energy storage pipeline includes a secondary energy storage device, a secondary circulating fan, and a secondary heat exchanger connected in sequence via pipelines. Gas circulates within the secondary energy storage pipeline. The secondary energy storage device contains solid heat storage material and an electric heater. The electric heater is used to heat the solid heat storage material. The output end of the steam-water separator is connected to the input end of the secondary heat exchanger via a fourth pipeline. The output end of the secondary heat exchanger is connected to a steam turbine or heating header via a fifth pipeline, and a second valve is provided on the fifth pipeline. The controller is electrically connected to the secondary energy storage device, the secondary circulating fan, and the electric heater, respectively.

3. The energy storage and peak-shaving system as described in claim 2, characterized in that, The steam delivery pipeline is also equipped with a first temperature detector, which is used to detect the temperature of the steam output from the output end of the first-stage heat exchanger. The controller is electrically connected to the first temperature detector and is configured to: Obtain the actual steam temperature t1 detected by the first temperature detector; Compare the actual steam temperature t1 with the preset steam temperature t2; When t1 > t2, open the first valve and close the second valve to deliver steam to the steam turbine or heating header; When t1≤t2, the second valve is opened and the first valve is closed, and the steam is delivered to the secondary heat exchanger for heat exchange.

4. The energy storage and peak-shaving system as described in claim 2, characterized in that, The solid heat storage material is concrete or inorganic silicate particles.

5. The energy storage and peak-shaving system as described in claim 2, characterized in that, Both the primary energy storage pipeline and the secondary energy storage pipeline are equipped with gas replenishment ports. Each gas replenishment port is connected to a gas storage tank via an eighth pipeline, and a third valve is installed on the eighth pipeline.

6. The energy storage and peak-shaving system as described in claim 5, characterized in that, Pressure detectors are installed on both the primary energy storage pipeline and the secondary energy storage pipeline. The two pressure detectors are used to detect the gas pressure on the primary and secondary energy storage pipelines, respectively. The two pressure detectors are electrically connected to the controller, which is further configured to: Obtain the actual gas pressure P1 detected by the pressure detector; Compare the actual gas pressure P1 with the preset gas pressure P2; When P1 < P2, open the third valve on the primary energy storage pipeline and / or the secondary energy storage pipeline to connect the gas supply port on the primary energy storage pipeline and / or the secondary energy storage pipeline with the gas storage tank. When P1≥P2, close the third valve on the primary energy storage pipeline and / or the secondary energy storage pipeline.

7. The energy storage and peak-shaving system as described in claim 1, characterized in that, A fourth valve is installed on the first pipeline; The energy storage and peak-shaving system further includes a gas pressurization pipeline, which includes a condenser and a circulating pump connected in sequence through a pipeline. The condenser is connected to the first-stage heat exchanger through a sixth pipeline. A fifth valve is provided on the sixth pipeline. One end of the first pipeline is connected to the sixth pipeline, and the other end is connected to the heat collection device. The circulating pump is connected to the heat collection device through a seventh pipeline.

8. The energy storage and peak-shaving system as described in claim 7, characterized in that, A second temperature detector is also provided on the sixth pipeline. The second temperature detector is located on the sixth pipeline and is used to detect the temperature of the gas after heat exchange with the first-stage heat exchanger. The controller is electrically connected to the second temperature detector and is further configured to: Obtain the actual gas temperature t3 detected by the second temperature detector; Compare the actual gas temperature t3 with the preset gas temperature t4; When t3 > t4, the fourth valve is opened to connect the first pipeline, and the fifth valve is closed. When t3≤t4, the fourth valve is closed and the fifth valve is opened to deliver the gas to the condenser for cooling to a liquid state. The cooled liquid is then delivered to the circulating pump for pressurization into gas, and finally delivered to the heat collection device.

9. The energy storage and peak-shaving system as described in claim 1, characterized in that, The heat collection device is a trough-type heat collector.

10. The energy storage and peak-shaving system as described in claim 1, characterized in that, Also includes: A water pump is provided, with its two ends connected to a steam-water separator and a primary heat exchanger via pipelines. The water pump is used to pump the liquid in the steam-water separator to the primary heat exchanger for heat exchange, and the water pump is electrically connected to the controller.

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