A heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank

Abstract

The present invention relates to the field of high-temperature molten salt heat storage technology, and in particular to a heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank. This system solves the technical defect that the current arrangement of the cooling air ducts in the foundation of the molten salt storage tank gradually reduces the heat exchange area in the radial direction, resulting in non-uniform settlement, which easily causes uneven temperature distribution in the foundation. The system includes an underground heat absorption device and an above-ground condensation device. The underground heat absorption device is pre-buried in the heat-resistant concrete layer of the foundation directly below the molten salt heat storage tank. The underground heat absorption device includes multiple groups of gas tank components evenly arranged along the circumference of the molten salt heat storage tank. The present invention utilizes the principle of heat absorption and evaporation of liquid coolant and heat absorption and expansion of gaseous coolant and condensation and heat release to effectively reduce and homogenize the foundation temperature and avoid uneven settlement of the tank. The above-ground condensation device of the present invention can adjust the condensation heat release efficiency through a valve to fully ensure that the condensation effect of the condensation devices in all directions around the tank is balanced, avoiding the adverse phenomenon of uneven heat dissipation of the foundation due to natural factors.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature molten salt heat storage, and in particular to a heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank. Background Art

[0002] The increasing share of renewable energy sources (such as photovoltaics, solar thermal, and wind power) in installed power capacity presents significant challenges to the stable operation of new power systems. Energy storage, as a high-quality flexible resource for regulating power grids, not only addresses the intermittent, fluctuating, and random fluctuations in renewable energy output but also enhances the controllability and flexibility of power systems. Therefore, fully leveraging energy storage technology has become a key development direction for building a clean, low-carbon, safe, and efficient new power system.

[0003] Molten salt thermal storage technology is a medium-to-high-temperature energy storage method characterized by high heat storage density, low vapor pressure, a wide operating temperature range, and the ability to achieve large-capacity and long-term energy storage. It utilizes nitrates (e.g., 40%wt KNO3 to 60%wt NaNO3) as a thermal storage medium. Green electricity, off-peak electricity, and steam are used to heat the molten salt to store renewable energy or off-peak electricity. This enhances the deep peak-shaving capabilities of thermal power units, promotes the integration of new energy sources, and improves grid security. Currently, molten salt thermal storage technology is widely used in a variety of applications, including solar thermal power plants, integrated wind, solar, thermal, and storage energy bases, flexible retrofits for thermal power units, and steam supply for industrial parks.

[0004] The molten salt heat storage tank is the core component of the energy storage system. During heat storage, the molten salt is heated to 400-565°C using solar energy, electricity, or thermal energy and stored in the high-temperature tank. During heat release, the high-temperature molten salt is pumped into the steam generation system via a molten salt pump. After heat exchange with water / steam, it produces high-temperature, high-pressure superheated steam, which then drives the steam turbine to generate power or directly supply steam to the industrial park. The cooled molten salt, now at 290°C, then flows back into the low-temperature tank, completing the heat storage and release cycle. Dual-tank molten salt heat storage technology offers high heat storage efficiency (>96%), facilitates large-capacity and long-term energy storage (6-15 hours), and holds great promise for future applications.

[0005] However, high-temperature molten salt heat storage tanks still face the following challenges during operation: To reduce heat loss and improve safety, the tank foundation requires excellent thermal insulation and load-bearing capacity. The conventional arrangement of cooling ducts in the molten salt tank foundation, where the heat exchange area gradually decreases along the radial direction, can easily lead to uneven temperature distribution in the foundation. Because temperature affects the mechanical properties of the structure, under high-temperature gravity loads of 10,000 tons, the tank foundation is prone to uneven strength distribution and non-uniform settlement. Furthermore, large non-uniform settlement can increase stress in the tank corner welds and the edge of the tank bottom, causing stress failure and cracking in the tank bottom plate welds. Reports indicate that both the GemaSolar in Spain and the NOOR Phase III solar thermal power tower power plants in Morocco have experienced molten salt leaks due to uneven foundation settlement, resulting in significant economic losses. Summary of the Invention

[0006] In order to overcome the technical defect that the current arrangement of cooling air ducts in the foundation of molten salt storage tanks gradually reduces the heat exchange area in the radial direction, which easily causes uneven temperature distribution in the foundation and uneven settlement of the tank body, the present invention provides a heat pipe cooling system for homogenizing the temperature distribution of the foundation of molten salt heat storage tanks.

[0007] The present invention provides a heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank, comprising an underground heat absorption device and an above-ground condensing device. The underground heat absorption device is pre-buried in the heat-resistant concrete layer of the foundation directly below the molten salt heat storage tank. The underground heat absorption device comprises a plurality of gas bin assemblies uniformly arranged along the circumference of the molten salt heat storage tank. Each gas bin assembly comprises a long gas bin arranged radially along the molten salt heat storage tank and a short gas bin group symmetrically arranged on the left and right sides of the long gas bin. The short gas bin group and the long gas bin are located at the same inclined position. In the plane, the inclined planes of multiple groups of gas chamber components are spliced ​​together to form an inverted pyramid structure; the short gas chamber group includes multiple gas chamber bodies whose lengths gradually decrease in the direction away from the long gas chamber. The long gas chamber is a cylindrical structure. A guide plate is fixed on the top of the long gas chamber along its length. Capillary infiltration layers are respectively attached to the inner walls of the long gas chamber on the left and right sides of the guide plate. The capillary infiltration layers are arranged along the length direction of the guide plate. The guide plate and the capillary infiltration layers on its left and right sides form a guide groove. The capillary infiltration layer on the left side of the guide plate The left edge of the layer is provided with a left infiltration layer protection card plate fixedly connected to the inner wall of the long gas bin along its length direction, and the left infiltration layer protection card plate and the inner wall of the long gas bin form a left infiltration layer slot. The right edge of the capillary infiltration layer on the right side of the guide plate is provided with a right infiltration layer protection card plate fixedly connected to the inner wall of the long gas bin along its length direction, and the right infiltration layer protection card plate and the inner wall of the long gas bin form a right infiltration layer slot. The structure of the gas bin body is the same as that of the long gas bin; the guide grooves of the gas bin body and the long gas bin are connected respectively There is a liquid inlet branch pipe, and the higher end of the gas bin body and the long gas bin is connected to the gas outlet branch pipe respectively. All the liquid inlet branches on the gas bin body and the long gas bin in the same gas bin assembly are converged through the liquid separation multi-way valve and connected to the liquid inlet main pipe. All the gas outlet branches on the gas bin body and the long gas bin in the same gas bin assembly are converged through the buffer bin and connected to the gas outlet main pipe. The ground condensing device is provided with a liquid outlet and an air inlet. The liquid outlet is connected to the liquid inlet main pipe through a check valve, and the air inlet is connected to the gas outlet main pipe through an exhaust valve.

[0008] During engineering design, the required coolant flow rate is calculated in advance based on the volume of each gas chamber in the same gas chamber assembly. The structural dimensions of the liquid separation multi-way valve and the corresponding liquid inlet branch pipes are designed. By adjusting the diameter of each liquid inlet branch pipe and the shape and dimensions of the liquid separation multi-way valve outlet, the coolant flow rate reaching each gas chamber is adapted to the volume of each gas chamber. The underground heat absorption device described in this invention is installed in the foundation below the molten salt heat storage tank and is cast under the tank together with the foundation before the molten salt heat storage tank is completed.

[0009] The process of coolant gasification and pressurization in the present invention is as follows: after the coolant is sucked into the capillary infiltration layer, the coolant absorbs the heat of the foundation and evaporates and gasifies. The gas in the long gas bin or the gas bin body continues to absorb heat, causing the pressure to increase, and the pressure in the gas bin reaches the threshold of the exhaust valve.

[0010] The process of gas pressure release and liquefaction in the ground condensing device of the present invention is as follows: after the gas pressure in the gas bin reaches the exhaust valve threshold, the exhaust valve opens to release gas into the ground condensing device to reduce the pressure. The gas enters the ground condensing device and quickly liquefies after heat exchange with the outside air, completing the gas-liquid phase conversion. The gas flows back to the bottom of the ground condensing device due to gravity. After the pressure release is completed, the coolant is re-pumped into the long gas bin and the capillary infiltration layer of the gas bin body.

[0011] During specific operation, the coolants that can be used include liquid ammonia, R22, R134a, propane, or acetone. The coolant can be replaced according to specific temperature requirements. The coolant in the long gas bin or gas bin body is heated and continuously evaporates. The gas continues to absorb heat and increase pressure in the gas bin, and is collected from the gas outlet branch pipe to the buffer bin. When the gas pressure in the gas bin reaches a certain pressure, the exhaust valve at the air inlet of the ground condensing device opens. The gas in the gas bin assembly passes through the buffer bin, the gas outlet main pipe, and the exhaust valve, and then enters the ground condensing device for cooling and liquefaction. After the coolant evaporates, the gas is cooled and liquefied in the ground condensing device, enters the liquid inlet main pipe through the check valve, and then enters the corresponding liquid inlet branch pipe of each gas bin through the liquid separation multi-way valve. After entering the long gas chamber or the chamber body, the coolant flows downward along the guide grooves of the long gas chamber or the chamber body, influenced by the installation angle of the long gas chamber and the chamber body itself. Along the way, it is absorbed by the capillary infiltration layers on both sides of the guide groove. The coolant fully and evenly contacts the inner boundary of the capillary infiltration layer. Under the capillary action, the coolant begins to diffuse from the inner boundary of the capillary infiltration layer to the entire capillary infiltration layer. Excess coolant is temporarily stored in the right and left infiltration layer slots. After the coolant completes the heat absorption and evaporation stage, the evaporated gas continues to absorb heat and expand in the long gas chamber and the chamber body, further increasing the pressure until it reaches the pressure set by the exhaust valve, at which point it is released.

[0012] Under the influence of gravity, coolant continuously gathers in the capillary wetting layer near the right or left wetting layer slot. After the heat absorption phase is completed and the long gas chamber and gas chamber body begin to depressurize, the coolant accumulated in the right or left wetting layer slot, which has not absorbed heat and evaporated into gas in time, begins to infiltrate the capillary wetting layer under the influence of capillary action, thereby accelerating the overall circulation efficiency of the system.

[0013] Preferably, the above-ground condensing device includes a multi-layer condensing cavity, which includes two upper and lower horizontal plates and two layers of inclined ring plates connected to the circumference of the horizontal plates. The two layers of inclined ring plates are connected to each other to form a closed integral structure with the upper and lower horizontal plates. The multi-layer condensing cavities are stacked in the vertical direction, and adjacent condensing cavities are connected. The liquid outlet and air inlet are located at the bottom of the lowest condensing cavity. The above-ground condensing device is also connected to an air pump connected to the condensing cavity. The air pump is used to pressurize the above-ground condensing device so that the coolant is discharged from the liquid outlet. The inclined ring plates around the horizontal plates can increase the condensation area and improve the condensation efficiency. The check valve is equipped with a conical rubber flow limiter, so that the coolant can flow down quickly only when the air pump is working.

[0014] Preferably, the middle portion of the upper surface of the guide plate along its length is higher than the left and right sides, forming guide ridges arranged along the length of the guide plate. Under the action of the guide ridges, the coolant in the guide groove flows to the capillary infiltration layers on the left and right sides respectively.

[0015] Preferably, the angle between the plane where each set of gas bin components is located and the horizontal plane is 1-10 degrees. The specific angle is determined according to the volume of different storage tanks. Setting such an angle is also to ensure that the condensed water can flow more smoothly down the guide groove.

[0016] Preferably, the central angle corresponding to the arcuate area of ​​the capillary infiltration layers on the left and right sides covering the inner wall of the long gas silo after splicing is 150°. Leveraging the wettability of the capillary infiltration layer for the coolant, the coolant diffuses autonomously throughout the capillary infiltration layer under capillary action. Due to the surface tension of the coolant, the coolant overcomes its own gravity and absorbs heat on the upper wall of the gas silo. Therefore, selecting an appropriate range for the central angle corresponding to the arcuate area of ​​the capillary infiltration layer covering the inner wall of the long gas silo after splicing can ensure heat absorption efficiency. At the same time, due to the porous nature of the capillary infiltration layer, the surface area of ​​the coolant is greatly increased after infiltration, thereby accelerating the coolant's heat absorption and evaporation, allowing the coolant to remove more heat per unit time. The entire system can fully utilize the triple effects of coolant evaporation, gas expansion, and external work to absorb heat, achieving a controlled reduction in the underground temperature of the molten salt heat storage tank. The structure of the infiltration layer in the gas silo body is the same as that of the infiltration layer in the long gas silo, and the corresponding central angle is 150°.

[0017] Preferably, the inner walls of the long gas chamber and the gas chamber body that are not covered by the capillary wetting layer are coated with a carbon oxide coating.

[0018] Preferably, the ground condensing device is installed at a position 2m above the ground. The ground condensing device is installed at a height of more than 2m to allow the heat to rise naturally after dissipation, thereby preventing the ground working area from overheating.

[0019] Preferably, six groups of gas bin assemblies are provided, each group of gas bin assemblies includes a long gas bin and six gas bin bodies, and the same gas bin assembly shares a ground condensing device, and the total length of the gas bin assembly extends from the projected center of the molten salt heat storage tank to the outside of the outer wall surface of the molten salt heat storage tank. The coverage range of the gas bin assembly is to ensure that the heat conducted from the molten salt heat storage tank to the foundation is fully reduced. The specific number of gas bin assemblies is set according to the size of the foundation of different storage tanks. Multiple ground condensing devices are evenly distributed on the circumference of the molten salt heat storage tank, which can fully ensure that the ground condensing devices in all directions can cool the foundation in all directions, and will not cause the problem of uneven underground heat dissipation due to the influence of natural wind.

[0020] In response to different molten salt heat storage tanks or environmental changes, the heat pipe cooling system of the present invention can adjust the tank foundation temperature drop effect in a variety of ways. The specific adjustment methods are as follows:

[0021] 1. Change the exhaust valve setting pressure. After the gas pressure in the gas chamber reaches a certain level after the gas chamber is extended, the exhaust valve opens to cool and condense the high-temperature gas. By changing the exhaust valve setting pressure, you can change the heat absorption time of the gas generated by the evaporation of the coolant in the gas chamber. At the same time, changing the stored gas pressure in the gas chamber can change the heat absorption of the gas expansion work.

[0022] 2. Change the working efficiency of the air pump. The coolant is pressurized by the air pump to quickly enter the capillary infiltration layer above the air chamber. By changing the working efficiency of the air pump, the coolant flow rate is changed to adjust the overall cooling efficiency of the system.

[0023] 3. Change the number of condensing chambers in the above-ground condensing unit. After the coolant evaporates, the gas must pass through the condensing chamber to cool and condense. With changing seasons or changes in the cooling requirements of the tank foundation, changing the number of condensing chambers in the above-ground condensing unit can change the gas cooling efficiency and the system's pressure relief efficiency, thereby improving the overall cooling efficiency of the system.

[0024] The technical solution provided by the present invention offers the following advantages over existing technologies: It utilizes the principle of liquid coolant absorbing heat and evaporating, while gaseous coolant absorbs heat and expands, releasing heat through condensation, to effectively reduce foundation temperature and achieve a uniform foundation temperature distribution, thereby preventing uneven settlement of the storage tank. The above-ground condensing device of the present invention can adjust the condensation heat release efficiency through a valve, ensuring a balanced condensation effect at all condensing devices around the tank, thus avoiding the adverse effect of uneven foundation heat dissipation caused by natural factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 Schematic diagram of the heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to the present invention being installed in the foundation of a molten salt heat storage tank;

[0028] Figure 2 A top view of the distribution of all gas chamber components in an embodiment of the present invention;

[0029] Figure 3 Schematic diagram of the coordination of the long gas chamber and the short gas chamber group in the gas chamber assembly according to one embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the gas storage assembly in an embodiment of the present invention after being connected to a ground condensing device;

[0031] Figure 5 A schematic diagram of a gas bin assembly according to an embodiment of the present invention wherein a long gas bin and a short gas bin group are connected in parallel and then connected to a ground condensing device;

[0032] Figure 6 2. It is a cross-sectional view of the long gas chamber or gas chamber body according to an embodiment of the present invention.

[0033] In the figure: 1. Molten salt heat storage tank; 2. Heat-resistant concrete layer; 3. Gas chamber assembly; 4. Long gas chamber; 5. Gas chamber body; 6. Guide plate; 7. Capillary infiltration layer; 8. Guide groove; 9. Left infiltration layer protection card plate; 10. Right infiltration layer protection card plate; 11. Liquid inlet branch pipe; 12. Gas outlet branch pipe; 13. Liquid separation multi-way valve; 14. Liquid inlet main pipe; 15. Buffer chamber; 16. Gas outlet main pipe; 17. Check valve; 18. Exhaust valve; 19. Condensation chamber; 20. Air pump. DETAILED DESCRIPTION

[0034] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all the embodiments.

[0036] The following is combined with Figures 1 to 6 Specific embodiments of the present invention are described in detail.

[0037] In one embodiment, Figure 1As shown, the heat pipe cooling system for homogenizing the temperature distribution of the foundation of the molten salt heat storage tank includes an underground heat absorption device and an above-ground condensing device. The underground heat absorption device is pre-buried in the heat-resistant concrete layer 2 of the foundation directly below the molten salt heat storage tank 1. The underground heat absorption device includes multiple groups of gas bin assemblies 3 uniformly arranged along the circumference of the molten salt heat storage tank 1. Each group of gas bin assemblies 3 includes a long gas bin 4 arranged radially along the molten salt heat storage tank 1 and short gas bin groups symmetrically arranged on the left and right sides of the long gas bin 4. The short gas bin group and the long gas bin 4 are located in the same inclined plane. The multiple groups of gas bin assemblies 3 are arranged in a uniform manner along the circumference of the molten salt heat storage tank 1. The inclined planes are spliced ​​together to form an inverted pyramid structure; the short gas bin group includes a plurality of gas bin bodies 5 whose lengths gradually decrease in the direction away from the long gas bin 4. The long gas bin 4 is a cylindrical structure. A guide plate 6 is fixed to the top of the long gas bin 4 along its length. Capillary infiltration layers 7 are respectively attached to the inner walls of the long gas bin 4 on the left and right sides of the guide plate 6. The capillary infiltration layers 7 are arranged along the length direction of the guide plate 6. The guide plate 6 and the capillary infiltration layers 7 on its left and right sides form a guide groove 8. The left edge of the capillary infiltration layer 7 on the left side of the guide plate 6 is provided along its length direction. There is a left infiltration layer protection card plate 9 fixedly connected to the inner wall of the long gas bin 4, and the left infiltration layer protection card plate 9 and the inner wall of the long gas bin 4 form a left infiltration layer slot. The right edge of the capillary infiltration layer 7 on the right side of the guide plate 6 is provided with a right infiltration layer protection card plate 10 fixedly connected to the inner wall of the long gas bin 4 along its length direction. The right infiltration layer protection card plate 10 and the inner wall of the long gas bin 4 form a right infiltration layer slot. The structure of the gas bin body 5 is the same as that of the long gas bin 4; the gas bin body 5 and the guide groove 8 of the long gas bin 4 are respectively connected to the liquid inlet branch pipe 11, and the gas bin body 5 and the long gas bin 4 are respectively connected to the liquid inlet branch pipe 11. The higher end of the gas bin 4 is connected to an outlet branch pipe 12 respectively. All liquid inlet branches 11 on the gas bin body 5 and the long gas bin 4 in the same gas bin assembly 3 are converged through a liquid separation multi-way valve 13 and connected to the liquid inlet main pipe 14. All gas outlet branches 12 on the gas bin body 5 and the long gas bin 4 in the same gas bin assembly 3 are converged through a buffer bin 15 and connected to the outlet main pipe 16. The ground condensing device is provided with a liquid outlet and an air inlet. The liquid outlet is connected to the liquid inlet main pipe 14 through a check valve 17, and the air inlet is connected to the outlet main pipe 16 through an exhaust valve 18.

[0038] During engineering design, the required coolant flow rate is calculated in advance based on the volume of each gas bin in the same gas bin assembly 3. The structural dimensions of the liquid separation multi-way valve 13 and the corresponding liquid inlet branch pipe 11 are designed. By changing the diameter of each liquid inlet branch pipe 11 and the shape and size of the outlet of the liquid separation multi-way valve 13, the coolant flow rate reaching each gas bin is adapted to the volume of each gas bin. The underground heat absorption device described in the present invention is installed in the foundation below the molten salt heat storage tank 1 and is cast under the tank together with the foundation before the molten salt heat storage tank 1 is completed. Multiple groups of gas bin assemblies 3 are all arranged at an angle, with the inner end of the long gas bin 4 or gas bin body 5 lower than the outer end. Therefore, the inclined planes of multiple groups of gas bin assemblies 3 can be spliced ​​to form an inverted pyramid structure.

[0039] The process of coolant gasification and pressurization in the present invention is as follows: after the coolant is absorbed into the capillary infiltration layer 7, the foundation insulation layer conducts heat to evaporate and gasify the coolant, the gas in the long gas bin 4 or the gas bin body 5 continues to absorb heat and the temperature rises, and the pressure in the gas bin reaches the threshold of the exhaust valve 18.

[0040] The process of gas pressure release and liquefaction in the ground condensing device of the present invention is as follows: after the gas pressure in the gas bin reaches the threshold value of the exhaust valve 18, the exhaust valve 18 opens to release gas into the ground condensing device to reduce the pressure. The gas enters the ground condensing device and quickly liquefies after heat exchange with the outside air, completing the gas-liquid phase conversion. Due to gravity, it flows back to the bottom of the ground condensing device. After the pressure release is completed, the coolant is re-pumped into the long gas bin 4 and the capillary infiltration layer 7 of the gas bin body 5.

[0041] During specific operation, the coolants that can be used include liquid ammonia, R-22, R134a, propane or acetone. The coolant can be replaced according to the specific temperature requirements. The coolant in the long gas bin 4 or the gas bin body 5 is heated and evaporates continuously, and the gas continues to absorb heat and pressurize in the gas bin, and is collected from the gas outlet branch 12 to the buffer bin 15. When the gas pressure in the gas bin reaches a certain pressure, the exhaust valve 18 of the air inlet of the ground condensing device is opened, and the gas in the gas bin assembly 3 passes through the buffer bin 15, the gas outlet main pipe 16, and the exhaust valve 18, and then enters the ground condensing device for cooling and liquefaction. After the coolant evaporates, the gas is cooled and liquefied in the ground condensing device, and then enters the liquid inlet main pipe 14 through the check valve 17, and then enters the liquid inlet branch 11 corresponding to each gas bin through the liquid separation multi-way valve 13. After the coolant enters the long gas bin 4 or the gas bin body 5, it flows downward along the guide groove 8 of the long gas bin 4 or the gas bin body 5, influenced by the installation inclination angle of the long gas bin 4 and the gas bin body 5, and is absorbed by the capillary infiltration layer 7 on both sides of the guide groove 8 along the way. The coolant fully and evenly contacts the inner boundary of the capillary infiltration layer 7. Under the capillary action, the coolant begins to diffuse from the inner boundary of the capillary infiltration layer 7 to the entire capillary infiltration layer 7. Excess coolant will be temporarily stored in the right infiltration layer slot and the left infiltration layer slot. After the coolant completes the heat absorption and evaporation stage, the gas formed by evaporation continues to absorb heat and expand in the long gas bin 4 and the gas bin body 5, further increasing the pressure until it reaches the pressure set by the exhaust valve 18 and is then released.

[0042] Under the influence of gravity, the coolant continuously gathers in the area of ​​the capillary wetting layer 7 near the right or left wetting layer slot. After the heat absorption phase ends and the long gas chamber 4 and gas chamber body 5 begin to depressurize, the coolant accumulated in the right or left wetting layer slot, which has not yet absorbed heat and evaporated into gas, begins to infiltrate the capillary wetting layer 7 under the influence of capillary action, thereby accelerating the overall circulation efficiency of the system.

[0043] Based on the above-mentioned embodiments, in a preferred embodiment, the above-ground condensing device includes a multi-layer condensing chamber 19, which comprises two upper and lower horizontal plates and two inclined ring plates connected to the circumference of the horizontal plates. The two inclined ring plates, when connected, form a sealed integral structure with the upper and lower horizontal plates. The multiple condensing chambers 19 are stacked vertically, and adjacent condensing chambers 19 are interconnected. The liquid outlet and air inlet are located at the bottom of the lowest condensing chamber 19. The above-ground condensing device is also connected to an air pump 20, which is connected to the condensing chamber 19 via an air pipe and is used to pressurize the above-ground condensing device so that the coolant is discharged from the liquid outlet. The inclined ring plates around the horizontal plates increase the condensation area and improve condensation efficiency. The check valve 17 is equipped with a conical rubber flow restrictor, which allows the coolant to flow rapidly only when the air pump 20 is operating.

[0044] Based on the above embodiments, in a preferred embodiment, the outer wall of the condensing cavity 19 is provided with heat dissipation ribs, and the communication ports of adjacent condensing cavities 19 are provided with closing valves, and the number of connected condensing cavities 19 is changed by adjusting the closing valves.

[0045] Based on the above embodiment, in a preferred embodiment, the middle portion of the upper surface of the guide plate 6 along its length is higher than the left and right side portions, forming guide ridges arranged along the length of the guide plate 6. Under the action of the guide ridges, the coolant in the guide groove 8 flows to the capillary infiltration layers 7 on the left and right sides. The middle portion of the guide plate 6 smoothly transitions to the left and right sides, respectively, facilitating the coolant in the guide groove 8 to flow to the left and right guide plates 6.

[0046] Based on the above embodiment, in a preferred embodiment, the angle between the plane where each set of gas bin assemblies 3 is located and the horizontal plane is 1-10 degrees. The specific angle is determined according to the volume of different storage tanks. This angle is also set to ensure that the condensed water flows more smoothly downward along the guide groove 8.

[0047] Based on the above embodiment, in a preferred embodiment, the central angle corresponding to the arc surface area of ​​the guide groove 8 and the capillary infiltration layer 7 on the left and right sides covering the inner wall of the long gas bin 4 after splicing is 150°. Utilizing the wettability of the capillary infiltration layer 7 to the coolant, the coolant diffuses autonomously into the entire capillary infiltration layer 7 under the capillary action. Due to the surface tension of the coolant, the coolant is able to overcome its own gravity and absorb heat on the upper wall of the gas bin. Therefore, selecting a suitable range for the central angle corresponding to the arc surface area of ​​the capillary infiltration layer 7 covering the inner wall of the long gas bin 4 after splicing can ensure heat absorption efficiency. At the same time, due to the porous nature of the capillary infiltration layer 7, the surface area of ​​the coolant is greatly increased after infiltrating the capillary infiltration layer 7, thereby accelerating the heat absorption and evaporation of the coolant, allowing the coolant to take away more heat per unit time. The entire system can fully utilize the triple effects of coolant evaporation and heat absorption, gas heat absorption and expansion, and gas external work and heat absorption to achieve controllable reduction of the underground temperature of the molten salt heat storage tank 1. The structure of the infiltration layer in the gas chamber body 5 is the same as that of the infiltration layer in the long gas chamber 4, and the corresponding central angles are both 150°.

[0048] On the basis of the above embodiments, in a preferred embodiment, the inner walls of the long gas chamber 4 and the gas chamber body 5 that are not covered by the capillary wetting layer 7 are coated with a cold oxidation coating.

[0049] Based on the above embodiment, in a preferred embodiment, the ground condensing device is installed at a height of 2 meters above the ground. The ground condensing device is installed at a height of more than 2 meters to allow the heat to rise naturally after dissipation, thereby preventing the ground working area from overheating.

[0050] On the basis of the above-mentioned embodiment, in a preferred embodiment, six groups of gas bin assemblies 3 are provided, each group of gas bin assemblies 3 includes a long gas bin 4 and six gas bin bodies 5, and the same gas bin assembly 3 shares a ground condensing device, and the total length of the gas bin assembly 3 extends from the projected center of the molten salt heat storage tank 1 to the outside of the outer wall surface of the molten salt heat storage tank 1. The coverage range of the gas bin assembly 3 is to ensure that the heat conducted from the molten salt heat storage tank 1 to the foundation is fully reduced. The specific number of gas bin assemblies 3 is set according to the size of the foundation of different storage tanks. Multiple ground condensing devices are evenly distributed on the circumference of the molten salt heat storage tank 1, which can fully ensure that the ground condensing devices in all directions can cool the foundation in all directions, and will not cause the problem of uneven underground heat dissipation due to the influence of natural wind.

[0051] The above description is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions have been made with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments, and they should all be included in the scope of protection of the claims.

Claims

1. A heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank, characterized in that: The invention comprises an underground heat absorption device and an above-ground condensation device, wherein the underground heat absorption device is pre-buried in a heat-resistant concrete layer (2) of a foundation directly below a molten salt heat storage tank (1), and the underground heat absorption device comprises a plurality of gas chamber components (3) uniformly arranged along the circumference of the molten salt heat storage tank (1), each gas chamber component (3) comprises a long gas chamber (4) arranged along the radial direction of the molten salt heat storage tank (1) and a short gas chamber component symmetrically arranged on the left and right sides of the long gas chamber (4), the short gas chamber component and the long gas chamber (4) are located in the same inclined plane, and the inclined planes of the plurality of gas chamber components (3) are spliced ​​to form an inverted pyramid structure; the short gas chamber component comprises a gas chamber with a length away from the long gas chamber (4) and a short gas chamber component (3) arranged along the radial direction of the molten salt heat storage tank (1). A plurality of gas bin bodies (5) are provided, which decrease in length step by step along the direction of the bin (4). The long gas bin (4) is a cylindrical structure. A guide plate (6) is fixed on the top of the long gas bin (4) along its length direction. Capillary infiltration layers (7) are respectively attached to the inner walls of the long gas bin (4) on the left and right sides of the guide plate (6). The capillary infiltration layers (7) are arranged along the length direction of the guide plate (6). The guide plate (6) and the capillary infiltration layers (7) on the left and right sides thereof form a guide groove (8). A left infiltration layer protection card fixedly connected to the inner wall of the long gas bin (4) is provided at the left edge of the capillary infiltration layer (7) on the left side of the guide plate (6) along its length direction. (9), the left infiltration layer protection card plate (9) and the inner wall of the long gas bin (4) form a left infiltration layer slot, the right edge of the capillary infiltration layer (7) on the right side of the guide plate (6) is provided with a right infiltration layer protection card plate (10) fixedly connected to the inner wall of the long gas bin (4) along its length direction, the right infiltration layer protection card plate (10) and the inner wall of the long gas bin (4) form a right infiltration layer slot, the structure of the gas bin body (5) is the same as that of the long gas bin (4); the guide grooves (8) of the gas bin body (5) and the long gas bin (4) are respectively connected to the liquid inlet branch pipe (11), and the higher ends of the gas bin body (5) and the long gas bin (4) are respectively The gas outlet branch pipe (12) is connected, all liquid inlet branch pipes (11) on the gas bin body (5) and the long gas bin (4) in the same gas bin assembly (3) converge through a liquid separation multi-way valve (13) and are connected to a liquid inlet main pipe (14), all gas outlet branch pipes (12) on the gas bin body (5) and the long gas bin (4) in the same gas bin assembly (3) converge through a buffer bin (15) and are connected to a gas outlet main pipe (16), and the ground condensing device is provided with a liquid outlet and an air inlet, the liquid outlet is connected to the liquid inlet main pipe (14) through a check valve (17), and the air inlet is connected to the gas outlet main pipe (16) through an exhaust valve (18).

2. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 1, characterized in that: The ground condensing device includes a multi-layer condensing cavity (19), which includes two upper and lower horizontal plates and two layers of inclined ring plates connected to the circumference of the horizontal plates. The two layers of inclined ring plates are connected to each other to form a closed overall structure with the upper and lower horizontal plates. The multi-layer condensing cavity (19) is stacked in a vertical direction, and adjacent condensing cavities (19) are connected. The liquid outlet and the air inlet are located at the bottom of the lowest condensing cavity (19), and the ground condensing device is also connected to an air pump (20) connected to the condensing cavity (19). The air pump (20) is used to pressurize the ground condensing device so that the coolant is discharged from the liquid outlet.

3. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 2, characterized in that: The outer wall of the condensation cavity (19) is provided with heat dissipation ribs, and the communication ports of adjacent condensation cavities (19) are provided with closing valves, and the number of connected condensation cavities (19) is changed by adjusting the closing valves.

4. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to any one of claims 1 to 3, characterized in that: The angle between the plane where each group of gas chamber components (3) is located and the horizontal plane is 1 to 10 degrees.

5. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 4, characterized in that: The middle portion of the upper surface of the guide plate (6) along its length direction is higher than the left and right side portions, forming guide ridges arranged along the length direction of the guide plate (6). Under the action of the guide ridges, the coolant in the guide groove (8) flows to the capillary infiltration layers (7) on the left and right sides respectively.

6. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 5, characterized in that: The guide groove (8) and the capillary infiltration layers (7) on the left and right sides are spliced ​​together to cover the arc surface area of ​​the inner wall of the long gas chamber (4), and the central angle corresponding to the arc surface area is 150°.

7. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 6, characterized in that: The inner walls of the long gas chamber (4) and the gas chamber body (5) that are not covered by the capillary wetting layer (7) are coated with an anti-oxidation coating.

8. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 7, characterized in that: The ground condensing unit is installed at a position 2m above the ground.

9. The heat pipe cooling system for homogenizing the temperature distribution of the foundation of a molten salt heat storage tank according to claim 8, characterized in that: Six groups of gas bin assemblies (3) are provided, each group of gas bin assemblies (3) comprises a long gas bin (4) and six gas bin bodies (5), and the same gas bin assembly (3) is connected to a ground condensing device, and the total length of the gas bin assembly (3) extends from the projected center of the molten salt heat storage tank (1) to the outside of the outer wall surface of the molten salt heat storage tank (1).

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