High-temperature molten salt storage tank that can freely expand and contract to release thermal stress

Abstract

A high-temperature molten salt storage tank that can freely expand and contract to release thermal stress includes a tank body, the bottom plate of the tank body is a cone with an upward cone angle, a sand cushion layer formed by sand filling is provided in the middle of the lower part of the tank body, the upper part of the sand cushion layer is a cone with an upward cone angle, a leak detection bottom plate is provided below the sand cushion layer, a plurality of thermocouples for temperature measurement are provided on the leak detection bottom plate, and the plurality of thermocouples are electrically connected to an electrical control device respectively, a liquid collecting tank is provided around the outer edge of the leak detection bottom plate, the lower part of the liquid collecting tank is connected to the liquid inlet of the drain pipe, and the liquid outlet of the drain pipe is connected to the molten salt collecting tank. The purpose is to provide a high-temperature molten salt storage tank that can effectively ensure the free expansion and contraction of the storage tank, release thermal stress, thereby ensuring the safe operation of the storage tank, and can timely detect molten salt leakage, recycle the leaked molten salt, and avoid pollution to the environment.

Description

Technical Field

[0001] The invention relates to the field of solar thermal power generation, and in particular to a high-temperature molten salt storage tank that can freely expand and contract to release thermal stress. Background Art

[0002] A major challenge in utilizing renewable energy, especially solar energy, is to deal with the intermittent supply of energy caused by weather, daytime sunlight fluctuations and seasonal changes. One way to effectively manage the variability of solar resources is to add thermal energy storage devices to it. When there is surplus power, the variable energy is stored, and then when the power generated by solar energy is insufficient or no power is generated, the stored energy is released, thereby meeting the demand for continuous power supply.

[0003] Solar thermal storage technology mainly uses molten salt storage tanks. At present, the basic structure design of the bottom of the molten salt storage tank has always been a difficult point in this field. The stability and thermal insulation of the molten salt storage tank are the top priorities of the basic design. The usual high-temperature molten salt storage tank foundation structure is that the bottom plate of the molten salt storage tank is directly in contact with the concrete ring wall. The friction coefficient of the contact surface of such a structure is large, which is not conducive to the free expansion and contraction of the molten salt storage tank, and it is easy to cause cracking of the large angle weld at the connection between the bottom plate and the wall plate, which poses a great hidden danger to the safety of the storage tank.

[0004] In addition, there is leakage in molten salt storage tanks, which makes them unable to be used normally and causes serious pollution to the environment. How to quickly detect molten salt leakage is currently a key issue in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a high-temperature molten salt storage tank that can effectively ensure the free expansion and contraction of the storage tank and release thermal stress, thereby ensuring the safe operation of the storage tank, and can promptly detect molten salt leakage, recover the leaked molten salt, and avoid pollution to the environment.

[0006] The high-temperature molten salt storage tank capable of freely retracting and releasing thermal stress of the present invention comprises a tank body, wherein the bottom plate of the tank body is a cone with an upward cone angle, a sand cushion layer formed by filling sand is provided in the middle part below the tank body, the upper part of the sand cushion layer is a cone with an upward cone angle, a leak detection bottom plate is provided below the sand cushion layer, a plurality of thermocouples for temperature measurement are provided on the leak detection bottom plate, the plurality of thermocouples are electrically connected to an electrical control device respectively, a liquid collecting tank is provided around the outer edge of the leak detection bottom plate, the lower part of the liquid collecting tank is connected to the liquid inlet of the liquid discharge pipe, and the liquid outlet of the liquid discharge pipe is communicated with the molten salt collecting tank;

[0007] A heat preservation and insulation layer is provided below the leak detection bottom plate, a heat dissipation layer is provided below the heat preservation and insulation layer, a plurality of ventilation pipes are provided in the heat dissipation layer, a sand and gravel filling layer is provided below the heat dissipation layer, and a concrete support layer is provided below the sand and gravel filling layer;

[0008] An annular high-temperature resistant concrete outer wall is arranged on the outer side of the top of the concrete support layer, an annular heat-insulating layer is arranged inside the high-temperature resistant concrete outer wall, an annular refractory brick inner wall is arranged inside the annular heat-insulating layer, and the outer wall of the sand cushion layer, the outer wall of the liquid collecting tank, the outer wall of the heat-insulating layer, the outer wall of the heat-dissipating layer and the outer wall of the sand and gravel filling layer are respectively attached to the inner wall of the refractory brick inner wall;

[0009] The top of the high temperature resistant concrete outer wall is provided with an annular bottom plate, the plate surface of the bottom plate is located in the horizontal direction, the lower end surface of the bottom plate is in contact with the inner side of the top of the high temperature resistant concrete outer wall, the top of the annular insulation layer and the top of the refractory brick inner wall, the outer side of the lower end surface of the tank body is in contact with the outer side of the top of the bottom plate, the bottom plate is sleeved in the annular baffle, and the lower part of the annular baffle is fixedly connected to the high temperature resistant concrete outer wall.

[0010] Preferably, the leak detection bottom plate is in a shape with a middle portion convex upward and a periphery concave downward.

[0011] Preferably, the horizontal cross-sections of the high temperature resistant concrete outer wall, the annular heat insulation layer, the refractory brick inner wall and the tank body are respectively circular.

[0012] Preferably, the cross-section of the liquid collecting trough is rectangular.

[0013] Preferably, the lower portion of the liquid collecting tank is connected to the liquid inlets of 4 to 16 liquid discharge pipes.

[0014] Preferably, a steel mesh is provided at the port of the ventilation pipe.

[0015] When the membrane-electrode-distance ion membrane electrolyzer buffer net of the present invention is in use, once the temperature measurement thermocouple provided on the leak detection bottom plate detects that the temperature is abnormal, it indicates that the molten salt in the tank body has leaked, thereby the molten salt leakage phenomenon can be quickly detected, and time is gained for taking relevant emergency measures. The present invention can also collect the leaked molten salt through the drain pipe and the molten salt collection tank for reuse. In addition, by setting the tank body on the bottom plate, and providing a sand cushion layer formed by sand filling in the middle of the lower part of the tank body, the friction coefficient of the contact surface at the bottom of the tank body is reduced, thereby allowing the tank body to expand and contract freely, effectively releasing the thermal stress of the storage tank, and avoiding excessive local stress at the large angle weld between the bottom plate and the wall plate of the tank body, thereby ensuring the safety of the storage tank. If the tank body is displaced, the annular baffle can effectively block it to prevent the tank body from continuously shifting toward one side. Therefore, the high-temperature molten salt storage tank of the present invention which can freely expand and contract to release thermal stress can effectively release the thermal stress on the storage tank, avoid excessive local stress on the tank body, thereby ensuring the safety of the storage tank, and can promptly detect molten salt leakage, recover the leaked molten salt, and avoid pollution to the environment.

[0016] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a front view of the structural schematic diagram of the high-temperature molten salt storage tank that can freely expand and contract to release thermal stress according to the present invention;

[0018] Figure 2 It is a schematic cross-sectional view of the high-temperature molten salt storage tank of the present invention that can freely expand and contract to release thermal stress along the horizontal direction where the thermocouple is located. DETAILED DESCRIPTION

[0019] like Figure 1 and Figure 2 As shown, the high-temperature molten salt storage tank that can freely expand and contract to release thermal stress of the present invention comprises a tank body 10, the bottom plate of the tank body 10 is a cone with a cone angle facing upward, a sand cushion layer 5 formed by filling with sand is provided in the middle part below the tank body 10, the upper part of the sand cushion layer 5 is a cone with a cone angle facing upward, a leak detection bottom plate 11 is provided below the sand cushion layer 5, a plurality of thermocouples 14 for temperature measurement are provided on the leak detection bottom plate 11, and the plurality of thermocouples 14 are electrically connected to the electrical control device respectively, a liquid collecting tank 13 is provided around the outer edge of the leak detection bottom plate 11, the lower part of the liquid collecting tank 13 is connected to the liquid inlet of the drain pipe 15, and the liquid outlet of the drain pipe 15 is communicated with the molten salt collecting tank;

[0020] A heat preservation and insulation layer 6 is provided below the leak detection bottom plate 11, a heat dissipation layer 7 is provided below the heat preservation and insulation layer 6, a plurality of ventilation pipes 16 are provided in the heat dissipation layer 7, a sand and gravel filling layer 8 is provided below the heat dissipation layer 7, and a concrete support layer 9 is provided below the sand and gravel filling layer 8;

[0021] An annular high-temperature resistant concrete outer wall 2 is provided on the outer side of the top of the concrete support layer 9, an annular heat-insulating layer 3 is provided inside the high-temperature resistant concrete outer wall 2, an annular refractory brick inner wall 4 is provided inside the annular heat-insulating layer 3, and the outer wall of the sand cushion layer 5, the outer wall of the liquid collecting tank 13, the outer wall of the heat-insulating layer 6, the outer wall of the heat-dissipating layer 7 and the outer wall of the sand and gravel filling layer 8 are respectively attached to the inner wall of the refractory brick inner wall 4;

[0022] The top of the high temperature resistant concrete outer wall 2 is provided with an annular bottom plate 1, the plate surface of the bottom plate 1 is located in the horizontal direction, the lower end surface of the bottom plate 1 is in contact with the inner side of the top of the high temperature resistant concrete outer wall 2, the top of the annular insulation layer 3 and the top of the refractory brick inner wall 4, the outer side of the lower end surface of the tank body 10 is in contact with the outer side of the top of the bottom plate 1, the bottom plate 1 is sleeved in the annular baffle 12, and the lower part of the annular baffle 12 is fixedly connected to the high temperature resistant concrete outer wall 2.

[0023] The bottom plate 1 is arranged at the bottom of the tank body 10 of the molten salt storage tank, and the annular baffle 12 is pre-buried in the high temperature resistant concrete outer wall 2. Since the outer annular surface of the bottom plate of the tank body 10 contacts the plane of the bottom plate 1, the sliding friction coefficient is small. The lower layer of the tank body 10 is a sand cushion layer 5, which is a mixture of coarse sand and fine sand. The upper part of the sand cushion layer 5 is a cone with an upward cone angle, which can stabilize the tank body 10 and insulate. The high temperature resistant concrete outer wall 2 can prevent the foundation from being able to withstand high temperature molten salt of nearly 600°C in the event of a large amount of molten salt leakage, and there will be no danger of the tank overturning.

[0024] As a further improvement of the present invention, the leak detection bottom plate 11 is shaped in such a way that the middle portion thereof is convex upward and the periphery thereof is concave downward.

[0025] As a further improvement of the present invention, the horizontal cross-sections of the high temperature resistant concrete outer wall 2, the annular heat insulation layer 3, the refractory brick inner wall 4 and the tank body 10 are respectively circular.

[0026] As a further improvement of the present invention, the cross section of the liquid collecting tank 13 is rectangular.

[0027] As a further improvement of the present invention, the lower portion of the liquid collecting tank 13 is connected to the liquid inlets of 4 to 16 liquid discharge pipes 15 .

[0028] As a further improvement of the present invention, a steel mesh is provided at the port of the ventilation pipe 16. The purpose of providing the steel mesh is to prevent small animals from getting into it.

[0029] When the membrane-electrode-distance ion membrane electrolyzer buffer net of the present invention is in use, once the temperature measurement thermocouple 14 provided on the leak detection bottom plate 11 detects that the temperature is abnormal, it indicates that the molten salt in the tank body 10 has leaked, thereby the molten salt leakage phenomenon can be quickly detected, and time is gained for taking relevant emergency measures. The present invention can also collect the leaked molten salt through the drain pipe 15 and the molten salt collection tank for reuse. In addition, by setting the tank body 10 on the bottom plate 1, and providing a sand cushion layer 5 formed by sand filling in the middle of the lower part of the tank body 10, the friction coefficient of the bottom contact surface of the tank body 10 is reduced, thereby allowing the tank body 10 to expand and contract freely, effectively releasing the thermal stress of the storage tank, and avoiding excessive local stress at the large angle weld between the bottom plate and the wall plate of the tank body 10, thereby ensuring the safety of the storage tank. If the tank body 10 is displaced, the annular baffle 12 can effectively block it to prevent the tank body 10 from continuously shifting toward one side. Therefore, the high-temperature molten salt storage tank of the present invention which can freely expand and contract to release thermal stress can effectively release the thermal stress on the storage tank, avoid excessive local stress on the tank body, thereby ensuring the safety of the storage tank, and can promptly detect molten salt leakage, recover the leaked molten salt, and avoid pollution to the environment.

[0030] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineers and technicians in the field should all fall within the protection scope of the claims of the present invention.

Claims

1. A high-temperature molten salt storage tank that can freely expand and contract to release thermal stress, characterized by: The invention comprises a tank body (10), wherein the bottom plate of the tank body (10) is in the shape of a cone with an upward cone angle, a sand cushion layer (5) formed by filling sand is provided in the middle of the bottom of the tank body (10), the upper part of the sand cushion layer (5) is in the shape of a cone with an upward cone angle, a leak detection bottom plate (11) is provided below the sand cushion layer (5), a plurality of thermocouples (14) for temperature measurement are provided on the leak detection bottom plate (11), the plurality of thermocouples (14) are respectively electrically connected to an electrical control device, a liquid collecting trough (13) is provided around the outer edge of the leak detection bottom plate (11), the lower part of the liquid collecting trough (13) is connected to the liquid inlet of a liquid discharge pipe (15), and the liquid outlet of the liquid discharge pipe (15) is communicated with a molten salt collecting tank; A heat preservation and insulation layer (6) is provided below the leak detection bottom plate (11), a heat dissipation layer (7) is provided below the heat preservation and insulation layer (6), a plurality of ventilation pipes (16) are provided in the heat dissipation layer (7), a sand and gravel filling layer (8) is provided below the heat dissipation layer (7), and a concrete support layer (9) is provided below the sand and gravel filling layer (8); An annular high-temperature resistant concrete outer wall (2) is provided on the outer side of the top of the concrete support layer (9), an annular heat-insulating layer (3) is provided inside the high-temperature resistant concrete outer wall (2), an annular refractory brick inner wall (4) is provided inside the annular heat-insulating layer (3), and the outer wall of the sand cushion layer (5), the outer wall of the liquid collecting tank (13), the outer wall of the heat-insulating layer (6), the outer wall of the heat-dissipating layer (7) and the outer wall of the sand and gravel filling layer (8) are respectively attached to the inner wall of the refractory brick inner wall (4); The top of the high temperature resistant concrete outer wall (2) is provided with an annular bottom plate (1), the plate surface of the bottom plate (1) is located in the horizontal direction, the lower end surface of the bottom plate (1) is in contact with the inner side of the top of the high temperature resistant concrete outer wall (2), the top of the annular heat insulation layer (3) and the top of the refractory brick inner wall (4), the outer side of the lower end surface of the tank body (10) is in contact with the outer side of the top of the bottom plate (1), the bottom plate (1) is sleeved in the annular baffle (12), and the lower part of the annular baffle (12) is fixedly connected to the high temperature resistant concrete outer wall (2).

2. The high-temperature molten salt storage tank capable of freely retracting and releasing thermal stress as claimed in claim 1 is characterized in that: The leak detection bottom plate (11) is in a shape with a middle portion convex upward and a periphery concave downward.

3. The high-temperature molten salt storage tank capable of freely retracting and releasing thermal stress as claimed in claim 2 is characterized in that: The horizontal cross-sections of the high-temperature resistant concrete outer wall (2), the annular heat insulation layer (3), the refractory brick inner wall (4) and the tank body (10) are respectively circular.

4. The high-temperature molten salt storage tank capable of freely expanding and contracting to release thermal stress as claimed in claim 3 is characterized in that: The cross section of the liquid collecting tank (13) is rectangular.

5. The high-temperature molten salt storage tank capable of freely expanding and contracting to release thermal stress as claimed in claim 4 is characterized in that: The lower part of the liquid collecting tank (13) is connected to the liquid inlets of 4 to 16 liquid discharge pipes (15).

6. The high-temperature molten salt storage tank capable of freely expanding and contracting to release thermal stress according to any one of claims 1 to 5, characterized in that: A steel mesh is provided at the end of the ventilation pipe (16).

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