Double-walled high-temperature molten salt storage tank

Abstract

A double-walled high-temperature molten salt storage tank includes an outer tank body. The bottom of the outer tank body is covered with a bottom insulation layer. An inner tank body is placed at the center of the top of the bottom insulation layer. An outer sidewall insulation layer surrounds the outer sidewall of the inner tank body. A cylindrical solid particle-filled cavity exists between the outer sidewall insulation layer and the inner wall of the outer tank body. This cavity is filled with flowable solid particles. A top insulation layer is provided on top of the inner tank body. An expansion cavity exists between the top insulation layer and the top plate of the outer tank body. The top of the solid particle layer communicates with the expansion cavity. The purpose is to provide a double-walled high-temperature molten salt storage tank that can absorb thermal deformation caused by temperature, thus preventing leakage due to excessive local stress, which could harm the environment, cause personal injury and property damage. It also aims to reduce the manufacturing cost of molten salt storage tanks, resulting in low heat loss and a long service life.

Description

Technical Field

[0001] This invention relates to the field of solar thermal power generation, and more specifically to a double-layered high-temperature molten salt storage tank. Background Technology

[0002] With the development of solar thermal power generation technology, molten salt storage tanks are evolving towards higher temperatures and larger sizes. Existing molten salt storage tanks are single-tank structures used at high temperatures and high liquid column static pressure. To ensure the tank's strength, expensive high-performance metal materials are often used, and the plates are quite thick. During operation, existing molten salt storage tanks expand and contract with changes in liquid level and temperature. If this expansion and contraction is not allowed, significant thermal stress will occur, potentially damaging the tank, causing leaks, and consequently harming the environment, resulting in personal injury and property damage. Traditional single-tank structures can only increase the thickness of the steel plates to ensure strength, which increases both the difficulty of steel plate processing and manufacturing, and the manufacturing cost of the molten salt storage tank. Summary of the Invention

[0003] The purpose of this invention is to provide a double-layered high-temperature molten salt storage tank that can absorb thermal deformation caused by temperature, thereby avoiding leakage caused by excessive local stress in the molten salt storage tank, which could harm the environment, cause personal injury and property damage, and reduce the manufacturing cost of the molten salt storage tank, resulting in low heat loss and long service life.

[0004] The double-layer high-temperature molten salt storage tank of the present invention includes an outer tank body, a bottom plate insulation layer laid at the bottom of the outer tank body, an inner tank body placed at the middle of the top of the bottom plate insulation layer, an outer side wall insulation layer surrounding the outer side wall of the inner tank body, a cylindrical solid particle filling cavity between the outer side wall insulation layer and the inner wall of the outer tank body, the solid particle filling cavity being filled with flowable solid particles, a top insulation layer at the top of the inner tank body, an expansion cavity between the top insulation layer and the top plate of the outer tank body, and the top of the solid particle filling cavity communicating with the expansion cavity.

[0005] A spring hanger is provided between the top plate of the outer tank and the top cover plate of the inner tank. The spring hanger includes multiple elastic rods. The top end of each elastic rod is connected to the top plate of the outer tank, and the bottom end of each elastic rod is connected to the top cover plate of the inner tank. A molten salt inlet pipe and a molten salt outlet pipe are connected to the top cover plate.

[0006] The top cover plate is fixedly connected to the outlet end of the molten salt inlet pipe and the inlet end of the molten salt outlet pipe, respectively. The molten salt inlet pipe and the molten salt outlet pipe extend upward and pass through the top plate of the outer tank body with clearance fit.

[0007] The elastic displacement of the spring hanger can be made along the vertical direction. The elastic displacement range of the spring hanger is greater than the maximum vertical displacement of the top cover plate when the inner tank expands to its limit due to heat. The tensile load that the spring hanger can withstand is greater than the sum of the weights of the top cover plate and the top insulation layer.

[0008] Preferably, the inner side of the upper part of the cavity filled with solid particles is chamfered, and the outer edge of the top cover plate is provided with a sleeve along the vertical direction to block the flowable solid particles, and the bottom end of the sleeve is fixedly connected to the top cover plate.

[0009] The bottom insulation layer, the side wall outer insulation layer, and the top insulation layer are made of rigid insulation material.

[0010] Preferably, each of the elastic rods is arranged along the vertical direction, and the elastic rod includes two connecting rods arranged in series at a distance along the vertical direction, with the two connecting rods connected in the middle by a tension spring.

[0011] Preferably, the outer tank and the inner tank have circular cross-sections and are coaxially arranged. The top plate of the outer tank is a spherical or butterfly-shaped end cap that bulges upward in the center. The top cover of the inner tank is circular, and the bottom plate of the inner tank has a shape that is raised in the middle and lower at the periphery.

[0012] Preferably, the outer tank is made of ordinary carbon structural steel, and the inner tank is made of heat-resistant steel.

[0013] Preferably, the inner tank is equipped with multiple temperature probes.

[0014] When the double-layer high-temperature molten salt storage tank of the present invention is in use, the temperature of the inner tank will rise when the inner tank is filled with high-temperature molten salt, causing the inner tank to expand and generate radial displacement. The outer insulation layer of the side wall, together with the wall plate of the inner tank, squeezes outward the solid particles filling the cavity. The wall plate of the outer tank is at room temperature and does not generate thermal deformation. Therefore, the space between the wall plates of the inner and outer tanks is compressed. The solid particles filling the cavity are fluid and are squeezed upward to the sleeve and blocked on the outside. At this time, the inner tank also has an upward axial displacement. The elastic suspension rod on the top of the inner tank can absorb the upward displacement of the inner tank. After the inner tank releases and discharges the high-temperature molten salt, its temperature decreases, causing it to contract and undergo radial displacement. The outer insulation layer of the inner tank's sidewall contracts and moves inward along with the inner tank's wall panels. The outer tank's wall panels remain at room temperature and do not undergo thermal deformation. This causes the solid particles filling the cavity between the inner and outer tanks to expand, and the solid particles at the sleeve begin to fall back to their original position. Simultaneously, the contracting inner tank also undergoes downward axial displacement. Consequently, the top cover of the inner tank moves downward, and the elastic tie rod on the top of the inner tank is stretched downward. This elastic tie rod generates an upward pulling force on the top cover 31 of the inner tank to prevent it from collapsing. Therefore, the double-layer high-temperature molten salt storage tank of this invention can absorb thermal deformation caused by temperature, avoiding leakage due to excessive local stress, which could harm the environment, cause personal injury and property damage. Furthermore, it reduces the manufacturing cost of molten salt storage tanks, resulting in low heat loss and a long service life.

[0015] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a front view of a structural schematic diagram of the double-layer high-temperature molten salt storage tank of the present invention;

[0017] Figure 2 for Figure 1 Top view. Detailed Implementation

[0018] like Figure 1 and Figure 2As shown, the double-layer high-temperature molten salt storage tank of the present invention includes an outer tank body 1, a bottom plate insulation layer 2 is laid at the bottom of the outer tank body 1, an inner tank body 3 is placed at the middle of the top of the bottom plate insulation layer 2, an outer side wall insulation layer 4 is arranged around the outer side wall of the inner tank body 3, a cylindrical solid particle filling cavity 6 is provided between the outer side wall insulation layer 4 and the inner wall of the outer tank body 1, the solid particle filling cavity 6 is filled with flowable solid particles, a top insulation layer 5 is provided at the top of the inner tank body 3, an expansion cavity 7 is provided between the top insulation layer 5 and the top plate of the outer tank body 1, and the top of the solid particle filling cavity 6 communicates with the expansion cavity 7.

[0019] The solid particles filling the cavity 6 are filled with flowable solid particles to absorb the horizontal radial displacement of the inner tank. The material used for the outer tank 1 should have sufficient strength to support the inner tank 3.

[0020] A spring hanger is provided between the top plate 11 of the outer tank 1 and the top cover plate 31 of the inner tank 3. The spring hanger includes multiple elastic rods 10. The top end of each elastic rod 10 is connected to the top plate 11 of the outer tank 1, and the bottom end of each elastic rod 10 is connected to the top cover plate 31 of the inner tank 3. A molten salt inlet pipe 9 and a molten salt outlet pipe 8 are connected to the top cover plate 31.

[0021] A spring hanger is provided between the top plate 11 of the outer tank 1 and the top cover plate 31 of the inner tank 3 to connect the top plate 11 of the outer tank 1 and the top cover plate 31 of the inner tank 3. The spring hanger can be used to absorb the axial displacement of the inner tank along the vertical direction.

[0022] The top cover plate 31 is fixedly connected to the outlet end of the molten salt inlet pipe 9 and the inlet end of the molten salt outlet pipe 8 respectively. The molten salt inlet pipe 9 and the molten salt outlet pipe 8 extend upward and pass through the top plate 11 of the outer tank body 1 with clearance fit.

[0023] The elastic displacement of the spring hanger can be made along the vertical direction. The elastic displacement range of the spring hanger is greater than the maximum vertical displacement of the top cover plate 31 when the inner tank 3 is heated to its limit. The tensile load that the spring hanger can withstand is greater than the sum of the weights of the top cover plate 31 and the top insulation layer 5.

[0024] The bottom insulation layer 2, the side wall outer insulation layer 4, and the top insulation layer 5 are made of rigid insulation material.

[0025] As a further improvement of the present invention, the inner side of the upper part of the solid particle filling cavity 6 is provided with a chamfer to prevent the solid particles from being stuck when flowing up and down. The outer edge of the top cover plate 31 is provided with a sleeve 12 for blocking the flowable solid particles along the vertical direction, and the bottom end of the sleeve 12 is fixedly connected to the top cover plate 31.

[0026] The sleeve 12 should be high enough to ensure that the solid particles, when heated and expanded, will not overflow into the area of ​​the spring hanger, nor will they come into contact with the top plate 11 of the outer tank 1, causing friction or compression. The solid particles should be made of lightweight materials to avoid creating excessive pressure on the inner and outer tanks, and should also have high compressive strength and good flowability.

[0027] As a further improvement of the present invention, each of the elastic rods 10 is arranged along the vertical direction, and the elastic rod 10 includes two connecting rods arranged in series at a distance along the vertical direction, and the two connecting rods are connected in the middle by a tension spring.

[0028] As a further improvement of the present invention, the cross-sections of the outer tank 1 and the inner tank 3 are circular, the outer tank 1 and the inner tank 3 are coaxially arranged, the top plate 11 of the outer tank 1 is a spherical end cap or a butterfly end cap that bulges upward in the middle, the top cover plate 31 of the inner tank 3 is circular, and the bottom plate of the inner tank 3 is a shape that bulges in the middle and sags around the perimeter.

[0029] As a further improvement of the present invention, the outer tank 1 is made of ordinary carbon structural steel, and the inner tank 3 is made of heat-resistant steel.

[0030] As a further improvement of the present invention, the inner tank 3 is provided with multiple temperature probes.

[0031] In the use of the double-layer high-temperature molten salt storage tank of the present invention, when the inner tank 3 is filled with high-temperature molten salt, the temperature of the inner tank 3 will rise, the inner tank 3 will expand, and a radial displacement will occur. The outer insulation layer 4 of the side wall, together with the wall plate of the inner tank 3, will squeeze the solid particles filling the cavity 6 outward. The wall plate of the outer tank 1 is at room temperature and does not produce thermal deformation. Therefore, the space between the wall plate of the inner tank 3 and the wall plate of the outer tank 1 is compressed. The solid particles filling the cavity 6 are fluid. The solid particles are squeezed and flow upward to the sleeve 12 and are blocked on the outside. At this time, the inner tank 3 also has an upward axial displacement. The elastic suspension rod on the top of the inner tank 3 can absorb the upward displacement of the inner tank. After the inner tank 3 releases and discharges the high-temperature molten salt, the temperature of the inner tank 3 decreases, and the inner tank 3 contracts and undergoes radial displacement. The outer insulation layer 4 of the side wall of the inner tank 3 contracts and moves inward along with the wall plate of the inner tank 3. The wall plate of the outer tank 1 is at room temperature and does not undergo thermal deformation, causing the solid particles filling the cavity 6 between the inner tank 3 and the outer tank 1 to expand. The solid particles at the sleeve 12 begin to fall back to their original position. The inner tank 3, which is undergoing contraction and movement, also has a downward axial displacement. As a result, the top cover plate 31 of the inner tank 3 moves downward, and the elastic tie rod 10 on the top of the inner tank is stretched downward. The elastic tie rod 10 thus generates an upward pulling force on the top cover plate 31 of the inner tank 3 to prevent the top cover plate 31 of the inner tank 3 from collapsing.

[0032] In the operation of this invention's double-walled high-temperature molten salt storage tank, the inner tank 3 transmits the hydrostatic pressure and stress of the liquid column to the outer tank wall through the external insulation layer 4 and solid particles. The outer tank 1 provides support for the inner tank 3, preventing it from yielding and fracturing due to high temperature and high hydrostatic pressure. Since the outer tank 1 operates at ambient temperature, its operating temperature is significantly lower than that of the inner tank. Therefore, the outer tank 1 does not require expensive high-performance metals to maintain its strength. Furthermore, because the outer tank 1 supports the inner tank 3, the inner tank 3's wall can be manufactured relatively thinner, reducing the amount of heat-resistant steel used. Thus, this invention's double-walled high-temperature molten salt storage tank absorbs thermal deformation caused by temperature, preventing leakage due to excessive local stress, which could harm the environment, cause personal injury and property damage. It also reduces manufacturing costs, minimizes heat loss, and extends service life.

[0033] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A double-walled high-temperature molten salt storage tank, characterized by: The application relates to a double-layered salt tank, which comprises an outer tank body (1), a bottom heat-insulating layer (2) arranged on the bottom of the outer tank body (1), an inner tank body (3) arranged on the top of the bottom heat-insulating layer (2), a side wall outer heat-insulating layer (4) arranged on the outer side of the side wall of the inner tank body (3), a cylindrical solid particle filling cavity (6) arranged between the side wall outer heat-insulating layer (4) and the inner wall of the outer tank body (1), and a top heat-insulating layer (5) arranged on the top of the inner tank body (3), wherein the solid particle filling cavity (6) is filled with flowable solid particles, and the top heat-insulating layer (5) and the top plate of the outer tank body (1) are connected through an expansion cavity (7), and the top end of the solid particle filling cavity (6) is communicated with the expansion cavity (7). A spring hanger is arranged between the top plate (11) of the outer tank body (1) and the top cover plate (31) of the inner tank body (3), and the spring hanger comprises a plurality of elastic pull rods (10), the top end of each elastic pull rod (10) is connected with the top plate (11) of the outer tank body (1), the bottom end of each elastic pull rod (10) is connected with the top cover plate (31) of the inner tank body (3), and the top cover plate (31) is connected with a molten salt inlet pipe (9) and a molten salt outlet pipe (8). The top cover plate (31) is fixedly connected with the outlet end of the molten salt inlet pipe (9) and the inlet end of the molten salt outlet pipe (8), and the molten salt inlet pipe (9) and the molten salt outlet pipe (8) are upwardly extended and pass through the top plate (11) of the outer tank body (1) through gap fit. The elastic displacement of the spring hanger can be carried out along the vertical direction, the elastic displacement range of the spring hanger is greater than the maximum displacement of the top cover plate (31) along the vertical direction when the inner tank body (3) is expanded to the limit, and the tensile load that can be borne by the spring hanger is greater than the sum of the weight of the top cover plate (31) and the top heat-insulating layer (5). The inner side of the upper part of the solid particle filling cavity (6) is provided with a chamfer, and the outer side edge of the top cover plate (31) is provided with a sleeve (12) for blocking the flowable solid particles along the vertical direction, and the bottom end of the sleeve (12) is fixedly connected with the top cover plate (31).

2. The double-wall high temperature molten salt storage tank of claim 1, wherein: The bottom heat-insulating layer (2), the side wall outer heat-insulating layer (4) and the top heat-insulating layer (5) are made of hard heat-insulating materials.

3. The double-wall high temperature molten salt storage tank of claim 2, wherein: Each elastic pull rod (10) is arranged along the vertical direction, and the elastic pull rod (10) comprises two connecting rods which are arranged in series along the vertical direction and are spaced apart.

4. The double-wall high temperature molten salt storage tank of claim 3, wherein: The cross section of the outer tank body (1) and the inner tank body (3) is circular, the outer tank body (1) and the inner tank body (3) are coaxially arranged, the top plate (11) of the outer tank body (1) is a spherical head or a butterfly head which is bulged upward in the middle, the top cover plate (31) of the inner tank body (3) is circular, and the bottom plate of the inner tank body (3) is convex in the middle and is low in the periphery.

5. The double-wall high temperature molten salt storage tank according to any one of claims 1 to 4, characterized in that: The outer tank body (1) is made of common carbon structural steel, and the inner tank body (3) is made of heat-resistant steel.

6. The double-wall high temperature molten salt storage tank of claim 5, wherein: A plurality of temperature measuring probes are arranged in the inner tank body (3).

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