Leak-proof high-temperature fused salt storage tank foundation

Abstract

The invention discloses an anti-leakage high-temperature fused salt storage tank foundation which comprises a cushion layer, an anti-leakage layer and a heat preservation layer which are sequentially distributed in a stacked mode from top to bottom, the anti-leakage layer is connected with a flow collecting groove and comprises a center plate and a plurality of layers of flow guide ring plates, the center plate is located in the center of the flow guide ring plates, and the flow guide ring plates are arranged in a stacked mode from top to bottom. The inner ring side of the first layer of flow guide ring plate is pressed below the center plate, the outer ring side of the first layer of flow guide ring plate is pressed above the inner ring side of the second layer of flow guide ring plate, and in every two adjacent layers of flow guide ring plates, the outer ring side of the upper layer of flow guide ring plate is pressed above the inner ring side of the lower layer of flow guide ring plate. The anti-leakage layer arranged between the basic thermal insulation material and the tank bottom cushion layer can freely expand, the influence of temperature difference is small, and when the tank body leaks, leaked fused salt can be discharged to an inspection well in time.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature molten salt storage tank foundations, and in particular relates to a leakage-proof high-temperature molten salt storage tank foundation. Background Art

[0002] With the rapid development of renewable energy around the world, energy storage plays an increasingly important role as a link between renewable energy and energy consumers. Molten salt thermal storage is a physical energy storage technology with low cost and high technical maturity. It is the key development direction of large-scale long-term energy storage technology and one of the key supporting technologies for my country to achieve the goal of absorbing a high proportion of renewable energy.

[0003] Due to long-term high-temperature molten salt corrosion, cyclic thermal stress during the heat charging and discharging process, and immature design, manufacturing, and installation technologies, many molten salt leakage accidents have occurred in recent years, such as the Cresscent Dunes power station in the United States and the Gemasolar power station in Spain. The accidents not only caused huge economic losses, but also aroused widespread concerns about the leakage of molten salt storage tanks, affecting the application prospects of molten salt heat storage technology.

[0004] After a tank leaks, the molten salt first flows into the base material at the bottom of the tank, destroying the base insulation layer, causing the insulation performance to fail or even reducing the bearing capacity. Since it is difficult to detect in time, the continuous leakage of molten salt may spread to the abutment or foundation, reducing the bearing capacity and affecting the structural safety, and contaminating the soil and groundwater. Molten salt tank leaks usually have the characteristics of gradually worsening from small to large scale. Early detection is a key technology to avoid the deterioration of leakage accidents.

[0005] Conventional molten salt storage tank foundations are provided with a concrete ring beam and sand as a cushion layer at the bottom of the tank, and a thermal insulation material is directly provided thereunder. When a leak occurs, the molten salt directly flows into the thermal insulation material; or only a whole piece of anti-leakage steel plate is laid between the cushion layer and the thermal insulation material, and a temperature measuring point is provided on the steel plate. However, there are the following problems:

[0006] (1) The sump has no slope and cannot discharge the leaked molten salt in time.

[0007] (2) Due to the large diameter of the tank bottom, there is a large temperature difference between the center and edge of the tank bottom. The temperature difference causes inconsistent thermal expansion of the steel plate, resulting in the edge of the steel plate being torn or wrinkles in the middle, and the expected anti-leakage and drainage effects cannot be achieved.

[0008] (3) The anti-leakage steel plate is close to the bottom of the tank, and the temperature difference between it and the tank body is small. The accuracy of the thermocouple itself is limited. It is difficult to accurately judge whether there is a leak by the temperature difference on the anti-leakage steel plate. Summary of the invention

[0009] In order to solve the above problems, the present invention provides a leakage-proof high-temperature molten salt storage tank foundation. The leakage-proof layer arranged between the basic insulation material and the tank bottom cushion layer can expand freely and is less affected by temperature differences. When the tank body leaks, the leaked molten salt can be discharged to the inspection well in time.

[0010] The embodiments of the present invention are implemented by the following technical solutions:

[0011] A leak-proof high-temperature molten salt storage tank foundation comprises a cushion layer, a leak-proof layer and a thermal insulation layer which are stacked in sequence from top to bottom, the leak-proof layer is connected with a collecting trough, the leak-proof layer comprises a center plate and a plurality of guide ring plates, the center plate is located at the center of the guide ring plate, the plurality of guide ring plates are stacked from top to bottom and form a guide slope with a slope of α, wherein the inner ring side of the first guide ring plate is pressed under the center plate, the outer ring side of the first guide ring plate is pressed on the inner ring side of the second guide ring plate, and in two adjacent guide ring plates, the outer ring side of the upper guide ring plate is pressed on the inner ring side of the lower guide ring plate.

[0012] In one embodiment of the present invention, the guide ring plate includes a plurality of arc plates, and the plurality of arc plates are snap-connected or overlapped in sequence.

[0013] In one embodiment of the present invention, the inner ring side of the arc plate is provided with a first hook for clamping the upper arc plate, and the outer ring side of the arc plate is provided with a second hook for clamping the lower arc plate.

[0014] In one embodiment of the present invention, one end of the arc plate is provided with a third hook connected to the previous arc plate, and the other end of the arc plate is provided with a fourth hook connected to the next arc plate.

[0015] In one embodiment of the present invention, the anti-leakage layer further comprises a plurality of overlapping cover plates, which are laid along the connection seams of the guide ring plates.

[0016] In one embodiment of the present invention, the collecting groove is formed by splicing a plurality of annular grooves.

[0017] In one embodiment of the present invention, the collecting trough is connected to a drain pipe, and the drain pipe is connected to the inspection well.

[0018] In one embodiment of the present invention, a temperature detection device is provided at the outlet end of the overflow pipe.

[0019] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0020] The anti-leakage layer of the present invention adopts a central plate and several layers of guide ring plates that are overlapped or clamped, and the whole forms a discharge slope. When encountering high-temperature molten salt leakage, the central plate and the guide ring plate are easy to expand freely, avoiding the anti-leakage layer as a whole from being destroyed by temperature stress caused by temperature difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the foundation of the leak-proof high-temperature molten salt storage tank in the present invention;

[0023] Figure 2 A top view of the anti-leakage layer of the present invention;

[0024] Figure 3 It is a longitudinal schematic diagram of the overlap of the center plate and the arc plate in the present invention;

[0025] Figure 4 It is a longitudinal schematic diagram of the center plate and the arc plate being clamped together in the present invention;

[0026] Figure 5 for Figure 4 A schematic diagram of the clamping connection between the annular upward arc plates;

[0027] Figure 6 for Figure 4 A three-dimensional schematic diagram of multiple arc plates being connected to each other;

[0028] Figure 7 for Figure 6 A first structural schematic diagram of the middle arc plate;

[0029] Figure 8 for Figure 6 A second structural schematic diagram of the middle arc plate;

[0030] Fig. 9 A schematic diagram of the arc plates being connected by hooks of overlapping cover plates and being connected between the arc plates in an annular manner;

[0031] Fig.10 for Fig. 9 A three-dimensional schematic diagram of multiple arc plates being connected to each other;

[0032] Fig.11 for Fig.10 First-person perspective diagram of the mid-arc plate;

[0033] Fig.12 for Fig.10 Schematic diagram of the middle arc plate from the second perspective;

[0034] Fig.13 It is a three-dimensional schematic diagram of the overlap of each layer of guide plates and the adjacent arc plates being hooked and clamped together through the overlap cover plate;

[0035] Fig.14 for Fig.13 Schematic diagram of the mid-arc plate.

[0036] Icons: 1- cushion layer, 2- anti-leakage layer, 21- center plate, 22- guide ring plate, 221- arc plate, 2211- first hook, 2212- second hook, 2213- third hook, 2214- fourth hook, 23- overlapping cover plate, 3- insulation layer, 41- collecting trough, 42- discharge pipe, 43- inspection well, 44- temperature detection device. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the present invention, it should be noted that if the terms "inside" or "outside" appear to indicate an orientation or position relationship, it is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0041] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "configure", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Example

[0043] Please refer to Figure 1-9 The present embodiment provides a leak-proof high-temperature molten salt storage tank foundation, including a cushion layer 1, a leak-proof layer 2 and a thermal insulation layer 3 stacked in sequence from top to bottom. The cushion layer 1 can use a concrete ring beam and sand as the cushion layer 1, and the thermal insulation layer 3 can use a ceramsite thermal insulation layer 3 or a calcium silicate board thermal insulation layer. The leak-proof layer 2 includes a central plate 21 and a plurality of guide ring plates 22. The central plate 21 and the plurality of guide ring plates 22 can use a 0.2-3 mm thick heat-resistant aluminum-zinc-coated steel plate or stainless steel. Plate or other non-permeable materials. In this embodiment, the center plate 21 and several layers of guide ring plates 22 are all made of stainless steel plates. The center plate 21 is a circular plate, and the guide ring plate 22 is an annular plate. Several layers of guide ring plates 22 are stacked from top to bottom. The center plate 21 is placed at the center of the first layer of guide ring plates 22. The center plate 21 and the guide ring plates 22 constitute a guide slope with a slope of α. When finding the slope, find the slope from the center of the lower layer of thermal insulation material to the outside, and the slope α can be 0.5% to 3%. Among them, the center plate 21 is pressed on the inner ring side of the first layer of guide ring plate 22, the outer ring side of the first layer of guide ring plate 22 is pressed on the inner ring side of the second layer of guide ring plate 22, and in two adjacent layers of guide ring plates 22, the outer ring side of the upper layer of guide ring plate 22 is pressed on the inner ring side of the lower layer of guide ring plate 22. The layers of steel plates in the entire anti-leakage layer 2 are completely compacted and sealed by the weight of the tank. The installation is simple without welding and the construction is convenient. When high-temperature molten salt leaks, the molten salt will flow downward along the guide slope and will not penetrate into the insulation layer 3, and the layers of steel plates can expand freely. If a whole steel plate is used as the anti-leakage layer 2, due to the large temperature difference between the center and the edge of the tank bottom, the thermal expansion of the steel plate caused by the temperature difference is inconsistent, resulting in the edge of the steel plate being torn or wrinkles in the middle, and the expected anti-leakage and drainage effects cannot be achieved. The anti-leakage layer 2 of this embodiment can effectively reduce the temperature stress caused by the temperature difference between the center and the edge of the storage tank, and avoid the edge of the whole steel plate being torn or the internal extrusion wrinkles being destroyed.

[0044] For details, please refer to Figure 3-8The guide ring plate 22 includes a plurality of arc plates 221, and the plurality of arc plates 221 are sequentially snap-fitted, overlapped, or a combination of snap-fitting and overlapped. The present embodiment adopts a snap-fitting structure. The inner ring side of the arc plate 221 is provided with a first hook 2211 for snapping the upper arc plate 221, and the outer ring side of the arc plate 221 is provided with a second hook 2212 for snapping the lower arc plate 221. One end of the arc plate 221 is provided with a third hook 2213 connected to the previous arc plate 221, and the other end of the arc plate 221 is provided with a fourth hook 2214 connected to the next arc plate 221. For example, the radial direction of the guide ring plate 22 is longitudinal, and the circumferential direction of the guide ring plate 22 is annular. The center plate 21 is snap-fitted with the arc plate 221, such as Figure 4 , hooks are provided at the edge of the center plate 21. When paving, in the longitudinal direction, the hooks of the center plate 21 are engaged with the first hooks 2211 of the arc plate 221, and between the upper and lower guide ring plates 22, the second hooks 2212 of the arc plate 221 in the first layer of guide ring plate 22 are engaged with the first hooks 2211 of the arc plate 221 in the second layer of guide ring plate 22; in the annular direction, as shown in FIG. Figure 5 That is, in the same side layer of guide ring plate 22, the third hook 2213 of the arc plate 221 is engaged with the arc plate 221 on the left, and the fourth hook 2214 of the arc plate 221 is engaged with the arc plate 221 on the right. The guide ring plate 22 of each layer is composed of a plurality of arc plates 221 spliced ​​in sequence. The structure of a single arc plate 221 in the annular direction is as follows: Figure 7 and Figure 8 As shown, a plurality of arc plates 221 are connected to each other. Figure 6 As shown, a single arc plate Figure 7 and Figure 8 shown, and Figure 7 and Figure 8 The arc plate structure substrate shown is the same, only the positions of the third hook 2213 and the fourth hook 2214 are different. When clamped, Figure 8 The third hook 2213 of the arc plate is Figure 7 The fourth hook 2214 of the arc plate is hooked and connected to connect more arc plates. In this embodiment, each layer of guide ring plate 22 is spliced ​​by 8 arc plates 221. When the high-temperature molten salt leaks to the anti-leakage layer 2, the guide ring plates 22 of each layer can expand freely, and the arc plates 221 can also expand freely, so as to avoid the edge of the whole steel plate being torn or the internal extrusion wrinkles being damaged.

[0045] In this embodiment, in the annular direction, the arc plates 221 may also be connected in another manner, such as Figure 9-12 As shown, Fig. 9 It is a structure in which a single arc plate 221 is arranged in the annular direction. Fig.10 It is a schematic diagram of a plurality of arc plates 221 being connected by overlapping the cover plate 23. Fig.11 and Fig.12It is a structural schematic diagram of a single arc plate 221. Specifically, two adjacent arc plates 221 are hooked and clamped through an overlapping cover plate 23, and the overlapping cover plate 23 is provided with a fifth hook clamped with the arc plate 221. Because each layer of the guide ring plates 22 is connected by a clamping connection, that is, the arc plates 221 of two adjacent layers are connected by a hook-and-clamping connection, and the arc plate 221 and the overlapping cover plate 23 are also connected by a hook-and-clamping connection, the high-temperature molten salt will not penetrate into the insulation layer 3 from the gap, and it can also prevent the edge of the entire steel plate from being torn or the internal extruded wrinkles from being damaged.

[0046] It should be noted that when the center plate 21 and the guide ring plate 22 and the guide ring plates 22 of each layer are overlapped, the structure is as follows: Figure 3 As shown, at the same time, in the annular direction, that is, in the same side layer of the guide ring plate 22, each arc plate 221 also adopts an overlapping manner. During installation, attention should be paid to the treatment of corner points, such as using staggered seams of upper and lower layers or hook-and-loop connection to wrap each other, so as to avoid the formation of leakage points.

[0047] It should be noted that when the center plate 21 and the guide ring plate 22 and the guide ring plates 22 of each layer are overlapped, the arc plate 221 can be formed as follows: Fig.13 and Fig.14 The structure shown prevents the molten salt from leaking into the insulation layer from the overlapping seams between the arc plates 221, i.e., it is a straight plate in the longitudinal direction, and a third hook 2213 and a fourth hook 2214 are respectively arranged on the left and right sides in the circumferential direction. In the longitudinal direction, the center plate 21 and the guide ring plate 22, and each layer of the guide ring plates 22 are overlapped by straight plates, and in the circumferential direction, i.e., in the same side layer of the guide ring plate 22, each arc plate 221 is hooked and clamped by an overlapping cover plate 23.

[0048] In this embodiment, please refer to Figure 2, a collecting trough 41 is connected to the periphery of the anti-leakage layer 2, and the collecting trough 41 is connected to a discharge pipe 42, which is connected to the inspection well 43, and the overflow pipe is provided with a temperature detection device 44. The collecting trough 41 is made of 1-3mm thick heat-resistant aluminum-plated steel plate or stainless steel plate or other non-permeable materials, each section is about 3-10m long, and the bottom surface is sloped 1-3% at both ends to facilitate the timely discharge of the leaked molten salt, and overlapped with the outermost ring plate 2. The longitudinal overlap is made at the connection with the discharge pipe 42, and a section of the collecting trough about 500-1000mm long is placed under the collecting troughs on both sides as a connecting section, and a hole is opened in the middle to connect with the discharge pipe 42. The discharge pipe 42 adopts DN50-DN100 steel pipe, which is connected to the collecting trough and the inspection well 43, and is arranged every 3-10 meters. Pebbles with a particle size of 20-40 and a stainless steel filter are placed at the entrance of the discharge pipe 42 as a reverse filtration device. The inspection well 43 can be built with steel or refractory bricks, or poured with concrete, with a diameter of φ600-1000mm. A cover with an observation hole is added to the inspection well 43, which is arranged every 3-10 meters. The temperature detection device 44 can be arranged on the outside of the collecting tank or on the discharge pipe 42 using a thermocouple or a temperature measuring optical fiber, connected to the main control, and set a temperature feedback signal warning. When there is a leak of molten salt flowing in, the temperature change is large and can be discovered in time. When the high-temperature molten salt leaks, the molten salt flows along the anti-leakage layer 2 to the collecting tank 41, and is discharged to the inspection well 43 in time through the discharge pipe 42, and the leakage signal is fed back in time through the temperature detection device 44.

[0049] The anti-leakage layer 2 of the present invention adopts a central plate 21 and several layers of guide ring plates 22 that are overlapped or clamped, and form a discharge slope as a whole. When encountering high-temperature molten salt leakage, the central plate 21 and the guide ring plate 22 are easy to expand freely, thereby avoiding the anti-leakage layer 2 as a whole from being destroyed by temperature stress caused by temperature difference.

[0050] The present invention uses overlapping or clamping steel plates as the anti-leakage layer 2, and forms a discharge slope as a whole, which can discharge the leaked molten salt in time and prevent the leaked molten salt from flowing into the insulation layer 3, thereby protecting the performance and safety of the basic insulation material and the load-bearing structure.

[0051] The leakage temperature measuring point of the present invention is arranged at the outer end of the discharge pipe 42. The temperature is low when there is no leakage. Once the molten salt leaks, the temperature will rise sharply. It can be assisted by observation through the inspection well 43. Compared with setting the measuring point on the anti-leakage steel plate at the bottom of the tank, it can accurately judge whether there is a leakage and is not affected by the accuracy of the thermocouple. Therefore, the leakage can be discovered in time and accurately and measures can be taken to prevent the accident from expanding.

[0052] The radial width of the guide ring plate of each circle of the anti-leakage layer of the present invention is small, so that the temperature difference at the edge is small, which is convenient for free expansion, and can effectively reduce the temperature stress caused by the temperature difference between the center and the edge of the storage tank, avoiding the edge of the whole steel plate from being torn or the internal extrusion wrinkles from being destroyed. If a whole steel plate is used, it needs to be welded together, which is easy to change after welding and has uneven welds. The layers of steel plates of the present invention are completely compacted and sealed by the weight of the tank, and the installation is simple without welding, and the construction is convenient. If a whole steel plate is used, welding requires a certain thickness, generally at least 2mm thick. The present invention does not require welding, and a thin steel plate, such as 0.5mm thick, can be selected, which can save about 70% of the material cost, and does not affect the overall stress condition of the foundation.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leak-proof high-temperature molten salt storage tank foundation, comprising a cushion layer, a leak-proof layer and a thermal insulation layer stacked in sequence from top to bottom, the leak-proof layer is connected to a collecting trough, characterized in that: The anti-leakage layer includes a central plate and several layers of guide ring plates, wherein the central plate is located at the center of the guide ring plate, and the several layers of guide ring plates are stacked from top to bottom to form a guide slope with a slope of α. The inner ring side of the first layer of guide ring plate is pressed under the center plate, and the outer ring side of the first layer of guide ring plate is pressed on the inner ring side of the second layer of guide ring plate. In two adjacent layers of guide ring plates, the outer ring side of the upper guide ring plate is pressed onto the inner ring side of the lower guide ring plate.

2. The leak-proof high-temperature molten salt storage tank foundation according to claim 1 is characterized in that: The guide ring plate comprises a plurality of arc plates, and the plurality of arc plates are clamped or overlapped in sequence.

3. The leak-proof high-temperature molten salt storage tank foundation according to claim 2 is characterized in that: The inner ring side of the arc plate is provided with a first hook for clamping the upper arc plate, and the outer ring side of the arc plate is provided with a second hook for clamping the lower arc plate.

4. The leak-proof high-temperature molten salt storage tank foundation according to claim 3 is characterized in that: One end of the arc plate is provided with a third hook connected with the previous arc plate, and the other end of the arc plate is provided with a fourth hook connected with the next arc plate.

5. The leak-proof high-temperature molten salt storage tank foundation according to claim 2, characterized in that: The anti-leakage layer also includes a plurality of overlapping cover plates, which are laid along the connection seams of the guide ring plates.

6. The leak-proof high-temperature molten salt storage tank foundation according to claim 1, characterized in that: The collecting groove is formed by splicing a plurality of annular grooves.

7. The leak-proof high-temperature molten salt storage tank foundation according to claim 6, characterized in that: The collecting tank is connected with a drain pipe, and the drain pipe is connected with the inspection well.

8. The leak-proof high-temperature molten salt storage tank foundation according to claim 7, characterized in that: A temperature detection device is provided at the outlet end of the overflow pipe.

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