A magnetic coupling type stirring module, and a heat storage tank, a carbon dioxide energy storage system comprising the module

Abstract

The application belongs to the technical field of carbon dioxide energy storage systems, and particularly relates to a magnetic coupling type stirring module, a heat storage tank comprising the module, and a carbon dioxide energy storage system. The structure of the stirring module comprises a center pipe body which is sleeved and arranged on a maintenance platform support column and located in the inside of a tank body, a radial connecting rod which is arranged on the outer ring surface of the center pipe body and used for rotating and stirring heat storage medium, a permanent magnet ring body unit which is arranged on the radial connecting rod, located in the inside of the tank body, and used for receiving the driving force of a magnetic coupling driving module, and a plurality of periodic pushing guide plate units which are screwedly arranged on the radial connecting rod and used for improving the heat cycle efficiency of the heat storage medium in the mode of rotating and pushing the heat storage medium at the outlet position of a high-temperature medium discharge pipe and the inlet position of a low-temperature medium inlet pipe respectively.

Description

Technical Field

[0001] This application belongs to the technical field of carbon dioxide energy storage systems, and particularly relates to a magnetically coupled stirring module, and a heat storage tank and a carbon dioxide energy storage system including the module. Background Technology

[0002] Carbon dioxide energy storage systems refer to a new, large-scale, long-term energy storage technology that utilizes the phase change characteristics of carbon dioxide to store and release electrical energy. This system offers advantages such as high electro-electric conversion efficiency, high energy density, long lifespan, and relatively low cost.

[0003] The working principle of a carbon dioxide energy storage system mainly includes:

[0004] During the energy storage phase, off-peak electricity or wind and solar power curtailment is used to compress carbon dioxide gas at normal temperature and pressure to a supercritical state. At the same time, the heat of compression is stored through a heat storage medium, and the carbon dioxide is liquefied and stored in a high-pressure storage tank.

[0005] During the energy release phase, the carbon dioxide in the high-pressure storage tank is heated and vaporized by the heater, and then enters the turbine expander to generate electricity. At the same time, the cold energy of the low-temperature heat storage medium is stored in the cold storage tank, and the carbon dioxide at the outlet of the final turbine is returned to the low-pressure storage tank.

[0006] Correspondingly, the existing carbon dioxide energy storage system mainly consists of: compression and expansion unit, heat storage and heat exchange system, gas storage tank, circulation and pipeline system, control system, and auxiliary facilities.

[0007] Specifically, the aforementioned heat storage tank belongs to the category of "heat storage and exchange systems," and its main function corresponds to "storing compressed heat through a heat storage medium." Common heat storage tanks used in carbon dioxide energy storage systems mainly consist of: a tank body, a stirring structure, a maintenance platform, platform support columns, a high-temperature medium discharge pipe, a low-temperature medium inlet pipe, and a drain pipe.

[0008] The working principle of the heat storage tank mainly includes the following four points.

[0009] 1. During the energy release phase, the high-temperature medium discharge pipe pumps out the high-temperature heat storage medium and sends it to the external heat exchanger to heat the CO2 working medium. The aforementioned high-temperature heat storage medium is, for example, molten salt at around 560°C.

[0010] 2. During the energy storage stage, the low-temperature medium inlet pipe will inject the low-temperature medium after absorbing heat from the external heat exchanger into the tank. It will settle naturally due to the density difference, reducing mixing losses. The aforementioned low-temperature medium is, for example, molten salt at around 290°C.

[0011] 3. The stirring structure can suppress the temperature stratification of the medium, accelerate the thermal response speed, enhance the solid-liquid heat transfer efficiency of the molten salt medium, and extend the life of the heat storage medium.

[0012] 4. The drain pipe adopts a dual-valve design to ensure safe isolation. During maintenance, the above-mentioned molten salt medium can be completely drained, thereby removing deposited impurities and solidified residues.

[0013] For example, the invention patent application with publication number CN116592680A and publication date of August 15, 2023 discloses a multi-stream waste heat storage tank, whose main structural components include: tank body, heat storage medium inlet, heat storage medium outlet, stirrer, first heat exchange section, cooling coil, second heat exchange section, heating coil, softened water tank, steam coil, and flue gas coil.

[0014] The waste heat storage tank in this invention patent application has the following advantages and functions: the stirrer is used to stir the heat storage medium in the inner cavity, so that the heat storage medium is kept in a flowing state in the inner cavity, so that the heat is always kept evenly distributed.

[0015] However, in actual use, this mixer still has at least the following shortcomings in practicality and relatively low safety level, specifically manifested as follows:

[0016] Its agitator structure requires the drive shaft to pass through the tank. Therefore, under high temperature and high pressure conditions, the dynamic sealing structure at the drive shaft position is prone to failure, which can easily lead to harmful phenomena such as leakage of heat storage medium. Summary of the Invention

[0017] This application provides a magnetically coupled stirring module, which aims to solve the technical problem of how to make the stirring structure suitable for the heat storage tank of a carbon dioxide energy storage system have both the high efficiency of basic stirring function and the safety of preventing leakage of the heat storage medium.

[0018] In addition, this application also provides a heat storage tank including the above-mentioned stirring module and a carbon dioxide energy storage system including the heat storage tank.

[0019] The technical solution adopted by this application to solve the above problems is: a magnetically coupled stirring module, the structure of which includes a central tube body sleeved on the support column of the maintenance platform and located inside the tank, a radial connecting rod disposed on the outer ring surface of the central tube body and used for rotating and stirring the heat storage medium, a permanent magnet ring body unit disposed on the radial connecting rod and located inside the tank body and used for receiving the driving force of the magnetically coupled driving module, and a number of periodic pushing guide plate units screwed on the radial connecting rod and used to improve the thermal circulation efficiency of the heat storage medium by rotating and pushing the heat storage medium at the outlet position of the high temperature medium discharge pipe and the inlet position of the low temperature medium inlet pipe respectively.

[0020] A further preferred technical solution includes a periodic flow guide frame unit disposed on the outer ring surface of the central tube body, located below all the radial connecting rods and radially inside the periodic push guide plate unit below, for second-order rotational push of the heat storage medium at the outlet position of the high-temperature medium discharge pipe.

[0021] A further preferred technical solution is that the permanent magnet ring unit includes a rotating ring with its inner ring surface disposed on the radial connecting rod and located vertically between the low-temperature medium inlet pipe and the high-temperature medium outlet pipe, and a permanent magnet sheet disposed on the outer ring surface of the rotating ring and used to receive the driving force of the magnetic coupling drive module.

[0022] A further preferred technical solution is that the periodic push guide plate unit includes at least two internal threaded rings screwed onto the radial connecting rod and abutting each other, and a rotary adjustable vertical plate disposed on at least one of the internal threaded rings and used to enhance the inlet jet distribution at the inlet position of the low temperature medium inlet pipe or reduce the outlet suction dead zone at the outlet position of the high temperature medium outlet pipe by rotating and pushing the heat storage medium.

[0023] A further preferred technical solution is that the periodic flow guide frame unit includes a safety protection ring sleeved on the central tube and located below all the radial connecting rods, used to cover the sewage pipe, and a second-stage pushing vertical plate located on the radial inner side of the rotatable adjustable vertical plate on the safety protection ring and located below it, used to rotate and push the heat storage medium.

[0024] A further preferred technical solution is that when the heat storage medium is discharged outward, the second-order pushing vertical plate is exposed to the gas phase, thereby reducing the rotational resistance of the stirring module, in order to warn of the minimum safe liquid level of the heat storage medium.

[0025] A further preferred technical solution is that the periodic flow guide frame unit further includes an interface disposed on the safety protection ring, into which the second-stage pushing vertical plate is inserted, and which is used to change the minimum safe liquid level of the heat storage medium by vertically sliding and adjusting the second-stage pushing vertical plate.

[0026] A heat storage tank includes a tank body, a maintenance platform support column, a high-temperature medium discharge pipe, a low-temperature medium inlet pipe, and a drain pipe. It also includes the aforementioned magnetically coupled stirring module and a magnetically coupled drive module sleeved on the tank body for driving the stirring module to rotate.

[0027] A further preferred technical solution includes an L-shaped elastic rod disposed on the lower end face of the magnetic coupling drive module and connected to the drain pipe, which is used to warn of the minimum safe liquid level of the heat storage medium by monitoring the driving operation reaction torque on the magnetic coupling drive module.

[0028] A carbon dioxide energy storage system, comprising the aforementioned heat storage tank.

[0029] The beneficial effects of this application include at least the following five points.

[0030] First, the stirring module is located entirely inside the tank and is driven by a drive module outside the tank through the principle of magnetic coupling. Therefore, there is no need to open a hole on the tank for the stirring function, thus preventing the heat storage medium from leaking due to the stirring function.

[0031] Secondly, in this stirring module, the radial connecting rod can provide basic and main stirring functions. At the same time, the direct effect of periodically pushing the guide plate unit is to rotate and push the heat storage medium. The indirect effect is to enhance the inlet jet distribution and reduce the outlet suction dead zone. The ultimate effect is to improve the thermal circulation efficiency of the heat storage medium, thereby ensuring that the heat storage tank has a highly efficient stirring function.

[0032] Third, in this stirring module, the periodic flow guide frame unit has at least the following three functions;

[0033] A. As a supplement to the heat storage medium rotation propulsion function of the lower periodic propulsion guide plate unit, it produces a "second-order rotation propulsion" effect;

[0034] B. By combining the elastic connection structure on the magnetic coupling drive module, the minimum safe liquid level can be warned through the principle of sudden change in reaction force torque, thereby improving the practicality and safety of the heat storage tank.

[0035] C. Cover the drain pipe to prevent workers from falling into the bottom drain area during maintenance.

[0036] Fourth, in this stirring module, the lower rotary adjustable vertical plate can provide a warning and supplementary function for the minimum safe liquid level warning function; the height of the second-stage push vertical plate is adjustable, thus making the aforementioned minimum safe liquid level also adjustable.

[0037] Fifth, in this heat storage tank, the magnetic coupling drive module is sufficiently close to the tank body, thereby increasing the magnetic coupling strength. However, it is difficult to install a sufficiently long elastic connection structure at the gap between the two. Therefore, this is the main function of the overall structure composed of the drain pipe and the L-shaped elastic rod, which allows the reaction torque on the magnetic coupling drive module to be easily and relatively accurately measured. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the stirring module in this application.

[0039] Figure 2 This is a schematic diagram showing the installation location of the stirring module in this application.

[0040] Figure 3 This is a schematic diagram of the position and structure of the periodic flow guide frame unit in this application.

[0041] Figure 4 This is a schematic diagram of the position and structure of the permanent magnet ring unit in this application.

[0042] Figure 5 This is a schematic diagram of the position and structure of the periodically driven guide vane unit in this application.

[0043] Figure 6 This is a schematic diagram showing the position and shape of the L-shaped elastic rod in this application.

[0044] Figure 7 This is a schematic diagram of the shape structure of a torque sensor in the prior art.

[0045] Figure 8 This is a schematic diagram showing the location of the inlet jet region and the blank distribution region of the inlet jet in this application from a top-down perspective.

[0046] Figure 9 This is a top-down view showing the locations of the outlet suction zone and the outlet suction dead zone in this application.

[0047] Figure 10 This is a schematic diagram showing the minimum safe liquid level of the heat storage medium in this application.

[0048] Figure 11 This is a schematic diagram illustrating the use of the vertically agitated heat storage medium in the tilted state of the rotatable adjustable vertical plate in this application.

[0049] The meanings of the markings in the diagram are as follows.

[0050] 1. Central tube body; 2. Radial connecting rod; 3. Permanent magnet ring body unit; 4. Periodic push guide plate unit; 5. Periodic guide frame body unit;

[0051] Rotating ring 301, permanent magnet sheet 302;

[0052] Internal threaded ring 401, rotatable adjustable vertical plate 402;

[0053] Safety protection ring 501, second-stage push vertical plate 502, plug interface 503;

[0054] 12. Tank body, 11. Maintenance platform support column, 13. High temperature medium discharge pipe, 14. Low temperature medium inlet pipe, 16. Sewage pipe, 18. Maintenance platform, 19. Vent.

[0055] Magnetic coupling drive module 15, L-shaped elastic rod 17, ball bearing 20, axial limit bearing 21, support platform 22, torque sensor 23;

[0056] a) Heat storage medium, b) Inlet jet region, c) Blank distribution region of inlet jet, d) Outlet suction region, e) Minimum safe liquid level, f) Detailed Implementation

[0057] The following description is merely a preferred embodiment of this application and is not intended to limit the scope of this application.

[0058] As attached Figure 1 -Appendix Figure 11 As shown, a magnetically coupled stirring module includes a central tube 1 sleeved on the maintenance platform support column 11 and located inside the tank 12; a radial connecting rod 2 disposed on the outer ring surface of the central tube 1 for rotating and stirring the heat storage medium a; a permanent magnet ring unit 3 disposed on the radial connecting rod 2 and located inside the tank 12 for receiving the driving force of the magnetically coupled drive module 15; and several periodic push guide plate units 4 screwed onto the radial connecting rod 2 and rotating and pushing the heat storage medium a at the outlet position of the high-temperature medium discharge pipe 13 and the inlet position of the low-temperature medium inlet pipe 14 to improve the thermal cycle efficiency of the heat storage medium a.

[0059] In this embodiment, the main body of the stirring module is made of a non-magnetic material, such as 304 stainless steel, titanium alloy, or high-temperature alloy. The purpose is to prevent the magnetic field generated by the magnetic coupling drive module 15 from being shielded, as the ferromagnetic material would short-circuit the magnetic flux, thereby causing the magnetic coupling to fail.

[0060] Specifically, the stirring module consists of: a central tube 1, 3-5 rows of radial connecting rods 2, each row including 10-20 radial connecting rods 2, a permanent magnet ring unit 3, and 6-10 periodic push guide plate units 4.

[0061] The central tube 1, radial connecting rod 2, and permanent magnet ring unit 3 are integrally formed. The periodic push guide plate unit 4 is screwed onto the uppermost and lowermost radial connecting rods 2, so that the installation height of the two sets of periodic push guide plate units 4 is flush with the upper low-temperature medium inlet pipe 14 and the lower high-temperature medium outlet pipe 13, respectively.

[0062] On the other hand, the reason why the stirring module, or the heat storage tank including the stirring module, has high efficiency in basic stirring function is mainly due to the following three reasons:

[0063] First, the radial connecting rods 2 are distributed in both the vertical and circumferential directions, giving their stirring function a large effective area;

[0064] Secondly, the set of periodic push guide plate units 4 at the height of the high temperature medium discharge pipe 13 can reduce the number and / or area of ​​the outlet suction dead zone, and the set of periodic push guide plate units 4 at the height of the low temperature medium inlet pipe 14 can enhance the inlet jet distribution and ultimately improve the thermal cycle efficiency of the heat storage medium a.

[0065] Third, as attached Figure 11 As shown, the periodic push guide plate unit 4 can also be used at an angle, so that the stirring function also has the outstanding effect of vertical stirring and mixing.

[0066] Finally, the reason why the stirring module or the heat storage tank including the stirring module has the advantage of not easily leaking the heat storage medium a is mainly because: the stirring module is completely located inside the tank body 12, there is no need for a physical structural connection between the permanent magnet ring unit 3 and the magnetic coupling drive module 15, and there is no need to open stirring holes on the tank body 12, thus making it difficult for the heat storage medium a to leak.

[0067] The structure of the stirring module also includes a periodic flow guide frame unit 5, which is disposed on the outer ring surface of the central tube 1, below all the radial connecting rods 2, and radially inside the periodic push guide plate unit 4 below it, for second-order rotational push of the heat storage medium a at the outlet position of the high-temperature medium discharge pipe 13.

[0068] In this embodiment, the periodic flow guide frame unit 5 and the central tube 1 are integrally formed. The meaning of the word "periodic" in both the periodic push guide plate unit 4 and the periodic flow guide frame unit 5 refers to:

[0069] The number of high-temperature medium discharge pipe 13 and low-temperature medium inlet pipe 14 is only one. During the rotation of the stirring module, for a certain periodic push guide plate unit 4 and a certain specific guide structure on the periodic guide frame unit 5, it cannot always be located at the pipe opening position of the high-temperature medium discharge pipe 13 and the low-temperature medium inlet pipe 14. Therefore, it can only periodically trigger the above-mentioned rotation to push the heat storage medium a.

[0070] Specifically, the periodic flow guide frame unit 5 has at least the following two functions.

[0071] First, compared to the periodic push guide plate unit 4, the periodic guide frame unit 5 is further away from the inlet of the high temperature medium discharge pipe 13 and the low temperature medium inlet pipe 14. Therefore, the rotational pushing effect of the latter on the heat storage medium a can be regarded as a supplement to the same effect of the former.

[0072] This is also the meaning of the term "second-order" mentioned above. Correspondingly, the rotational driving effect of the heat storage medium in the periodically driving guide plate unit 4 corresponds to the "first-order, main" effect.

[0073] Second, the periodic flow guide frame unit 5 appropriately covers the sewage pipe 16 to prevent workers from falling into the bottom sewage area during maintenance.

[0074] The permanent magnet ring unit 3 includes a rotating ring 301 with its inner ring surface disposed on the radial connecting rod 2 and located vertically between the low-temperature medium inlet pipe 14 and the high-temperature medium outlet pipe 13, and a permanent magnet sheet 302 disposed on the outer ring surface of the rotating ring 301 and used to receive the driving force of the magnetic coupling drive module 15.

[0075] In this embodiment, the maintenance platform support column 11 is further provided with two axial limiting bearings 21 for vertically positioning the central tube 1 and reducing the frictional resistance between the central tube 1 and the maintenance platform support column 11. Accordingly, the inner annular surface of the central tube 1 does not contact the annular surface of the maintenance platform support column 11.

[0076] In addition, two sets of protrusions, one above the other, can be provided on the inner ring surface of the tank 12 to support and limit the rotating ring 301, thereby fixing the stirring module vertically.

[0077] The permanent magnet sheet 302 is made of, for example, a high-temperature samarium cobalt magnet with a fan-shaped cross-section. The distance between its outer ring surface and the inner ring surface of the tank 12 is ≤1.0cm, thereby improving the strength of magnetic coupling.

[0078] Specifically, the permanent magnet pieces 302 are arranged in 10-20 rows on the outer ring surface of the rotating ring 301, and each row includes 5-20 permanent magnet pieces 302. The rotating ring 301 is also provided with a high-temperature epoxy coating for covering the permanent magnet pieces 302, thereby preventing molten salt from corroding the permanent magnet pieces 302.

[0079] In addition, the heat storage medium a is, for example, a mixed molten salt of 60 wt% sodium nitrate and 40 wt% potassium nitrate.

[0080] The periodic push guide plate unit 4 includes at least two internal threaded rings 401 screwed onto the radial connecting rod 2 and abutting each other, and a rotary adjustable vertical plate 402 disposed on at least one of the internal threaded rings 401 and used to enhance the inlet jet distribution at the inlet position of the low temperature medium inlet pipe 14 or reduce the outlet suction dead zone at the outlet position of the high temperature medium outlet pipe 13 by rotating and pushing the heat storage medium a.

[0081] In this embodiment, the topmost and bottommost two radial connecting rods 2 are provided with threaded sections for stable installation of the internal threaded ring 401. The internal threaded ring 401, which is provided with the rotatable adjustable vertical plate 402, is integrally formed with the rotatable adjustable vertical plate 402.

[0082] The adjustable vertical plate 402 can be either completely vertical or tilted vertical when rotating and stirring the heat storage medium a. The former provides greater circumferential stirring and mixing, while the latter can also provide outstanding vertical mixing effect for the heat storage medium a.

[0083] Specifically, the tilt of each of the aforementioned adjustable vertical plates 402 can be adjusted and set during the maintenance of the heat storage tank, and its tilt will not change when the heat storage tank is in normal use.

[0084] The periodic flow guide frame unit 5 includes a safety protection ring 501 sleeved on the central tube 1 and located below all the radial connecting rods 2, used to cover the drain pipe 16, and a second-stage pushing vertical plate 502 located on the radial inner side of the rotatable adjustable vertical plate 402 on the safety protection ring 501 and located below it, used to rotate and push the heat storage medium a.

[0085] In this embodiment, the vertical projection of the safety protection ring 501 covers the sewage pipe 16, and its outer diameter is smaller than the inner diameter of the rotating ring 301. For details, please refer to the attached diagram. Figure 2 .

[0086] When the heat storage medium a is discharged outward, the second-order actuating vertical plate 502 is exposed to the gas phase, thereby reducing the rotational resistance of the stirring module, in order to warn of the minimum safe liquid level of the heat storage medium a.

[0087] In this embodiment, both the rotatable adjustable vertical plate 402 and the second-order pushing vertical plate 502 are rectangular in shape, but the difference is that the long side of the rotatable adjustable vertical plate 402 is vertical, while the long side of the second-order pushing vertical plate 502 is horizontal.

[0088] Therefore, the decrease in rotational resistance when the surface of the heat storage medium a crosses the rotary adjustable vertical plate 402 is relatively insignificant. For the torque surge alarm function at the minimum safe liquid level, the second-stage actuating vertical plate 502 is the primary mechanism, with the rotary adjustable vertical plate 402 serving as a secondary mechanism.

[0089] Correspondingly, the sudden torque change caused when the surface of the heat storage medium a crosses the set of the lower rotary adjustable vertical plates 402 can serve as a warning and / or calibration for the liquid level warning function of the second-order actuating vertical plate 502.

[0090] The periodic flow guide frame unit 5 also includes an interface 503 that is disposed on the safety protection ring 501, and is inserted into the second-stage push vertical plate 502, and is used to change the minimum safe liquid level of the heat storage medium a by vertically sliding and adjusting the second-stage push vertical plate 502.

[0091] In this embodiment, the installation height of the second-stage push vertical plate 502 on the insertion interface 503 remains unchanged during the use of the heat storage tank, thereby making the minimum safe liquid level adjustable.

[0092] Specifically, the safety protection ring 501 is provided with a horizontal nut, and the second-stage pushing vertical plate 502 is provided with vertically arranged openings, so that although the above-mentioned lifting adjustment is difficult to adjust steplessly, it has outstanding positional stability after adjustment.

[0093] A heat storage tank includes a tank body 12, a maintenance platform support column 11, a high-temperature medium discharge pipe 13, a low-temperature medium inlet pipe 14, and a drain pipe 16. It also includes a magnetically coupled stirring module as described in any one of claims 1-7, and a magnetically coupled drive module 15 sleeved on the tank body 12 and used to drive the stirring module to rotate.

[0094] In this embodiment, the distance between the inner ring surface of the magnetic coupling drive module 15 and the outer ring surface of the tank 12 is also ≤1.0cm, thereby improving the strength of magnetic coupling.

[0095] The structure of the heat storage tank also includes an L-shaped elastic rod 17 disposed on the lower end face of the magnetic coupling drive module 15 and connected to the drain pipe 16, which is used to warn of the minimum safe liquid level of the heat storage medium a by monitoring the driving operation reaction torque on the magnetic coupling drive module 15.

[0096] In this embodiment, the upper end of the vertical segment of the L-shaped elastic rod 17 is fixedly connected to the lower surface of the magnetic coupling drive module 15. The radially inner end of the transverse segment of the L-shaped elastic rod 17 is fixedly connected to the drain pipe 16, thereby solving the problem that the magnetic coupling drive module 15 and the tank 12 cannot be provided with an elastic structure of sufficient length due to excessive close contact.

[0097] Specifically, a commercially available torque sensor 23 is also provided on the horizontal section relatively close to the drain pipe 16, so that the torque change phenomenon formed at the second-order push vertical plate 502 can be effectively amplified and measured, ensuring the effectiveness of the liquid level warning function.

[0098] Correspondingly, the support platform 22 is provided with a circular hole, and the ball bearing 20 on the lower surface of the magnetic coupling drive module 15 supports and rolls on the upper surface of the support platform 22, thereby making the magnetic coupling drive module 15 relatively easy to be driven to rotate by the reaction force of magnetic coupling.

[0099] A carbon dioxide energy storage system, comprising the aforementioned heat storage tank.

[0100] In this embodiment, an existing heat exchanger is provided between the high-temperature medium discharge pipe 13 and the low-temperature medium inlet pipe 14, thereby enabling the heat storage function of the heat storage tank to be effectively performed.

[0101] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various modifications can be made without departing from the spirit of this application. These are non-inventive modifications and are protected by patent law as long as they are within the scope of the claims of this application.

Claims

1. A magnetically coupled stirring module, characterized in that: The structure includes a central tube (1) sleeved on the maintenance platform support column (11) and located inside the tank (12), a radial connecting rod (2) set on the outer ring surface of the central tube (1) and used for rotating and stirring the heat storage medium (a), a permanent magnet ring unit (3) set on the radial connecting rod (2) and located inside the tank (12) and used for receiving the driving force of the magnetic coupling drive module (15), and a number of periodic push guide plate units (4) screwed on the radial connecting rod (2) and used to improve the thermal cycle efficiency of the heat storage medium (a) by rotating and pushing the heat storage medium (a) at the outlet position of the high temperature medium discharge pipe (13) and the inlet position of the low temperature medium inlet pipe (14). The permanent magnet ring unit (3) includes a rotating ring (301) with its inner ring surface disposed on the radial connecting rod (2) and located vertically between the low-temperature medium inlet pipe (14) and the high-temperature medium outlet pipe (13), and a permanent magnet sheet (302) disposed on the outer ring surface of the rotating ring (301) and used to receive the driving force of the magnetic coupling drive module (15).

2. The magnetically coupled stirring module according to claim 1, characterized in that: It also includes a periodic flow guide frame unit (5) disposed on the outer ring surface of the central tube (1), located below all the radial connecting rods (2) and radially inside the periodic push guide plate unit (4) below, for second-order rotational push of the heat storage medium (a) at the outlet position of the high temperature medium discharge pipe (13).

3. The magnetically coupled stirring module according to claim 2, characterized in that: The periodic push guide plate unit (4) includes at least two internal threaded rings (401) screwed onto the radial connecting rod (2) and abutting each other, and a rotary adjustable vertical plate (402) disposed on at least one of the internal threaded rings (401) and used to enhance the inlet jet distribution at the inlet position of the low temperature medium inlet pipe (14) or reduce the outlet suction dead zone at the outlet position of the high temperature medium outlet pipe (13) by rotating and pushing the heat storage medium (a).

4. A magnetically coupled stirring module according to claim 3, characterized in that: The periodic flow guide frame unit (5) includes a safety protection ring (501) sleeved on the central tube (1) and located below all the radial connecting rods (2) for covering the drain pipe (16), and a second-stage pushing vertical plate (502) located on the radial inner side of the rotatable adjustable vertical plate (402) on the safety protection ring (501) and located below it for rotating and pushing the heat storage medium (a).

5. A magnetically coupled stirring module according to claim 4, characterized in that: When the heat storage medium (a) is discharged outward, the second-stage pusher vertical plate (502) is exposed to the gas phase, thereby reducing the rotational resistance of the stirring module, in order to warn of the minimum safe liquid level of the heat storage medium (a).

6. A magnetically coupled stirring module according to claim 5, characterized in that: The periodic flow guide frame unit (5) also includes an interface (503) which is disposed on the safety protection ring (501) and inserted into the second-stage push vertical plate (502), and is used to change the minimum safe liquid level of the heat storage medium (a) by adjusting the second-stage push vertical plate (502) by vertical sliding.

7. A heat storage tank, comprising a tank body (12), a maintenance platform support column (11), a high-temperature medium discharge pipe (13), a low-temperature medium inlet pipe (14), and a drain pipe (16), characterized in that: It also includes a magnetically coupled stirring module as described in any one of claims 1-6, and a magnetically coupled drive module (15) sleeved on the tank (12) and used to drive the stirring module to rotate.

8. A heat storage tank according to claim 7, characterized in that: It also includes an L-shaped elastic rod (17) disposed on the lower end face of the magnetic coupling drive module (15) and connected to the drain pipe (16), and used to warn of the minimum safe liquid level of the heat storage medium (a) by monitoring the driving operation reaction torque on the magnetic coupling drive module (15).

9. A carbon dioxide energy storage system, characterized in that: The structure includes the heat storage tank as described in any one of claims 7 and 8.

Images