A molten salt heat storage tank device

Abstract

The utility model relates to the field of fused salt heat storage tank, disclose a kind of fused salt heat storage tank device, including inner storage tank, closed cavity for storing fused salt is opened in inner storage tank, inner storage tank is set in outer cylinder, interlayer is equipped between the two;The protruding portion that occupies bottom space is further equipped in the inner storage tank.The utility model has the beneficial effects of improving the safety performance and heat preservation performance of fused salt heat storage tank, avoiding leakage of fused salt, reducing safety risk, reducing the residual rate of fused salt in the tank, using tank outer heat exchange, simple structure in the tank, avoiding safety hazard, reducing the heat exchange energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of molten salt thermal storage tanks, and in particular to a molten salt thermal storage tank device. Background Technology

[0002] Molten salt storage tanks are containers used to store high-temperature molten salt. Currently, most existing molten salt thermal storage tanks adopt a single-layer tank structure, which has the following problems: insufficient safety, when the storage tank leaks, the molten salt will flow directly out of the tank and into the outside, causing a safety accident; poor heat preservation effect, the heat preservation performance of a single-layer tank is limited, resulting in a large heat loss; traditional flat-bottomed molten salt thermal storage tanks have a large bottom area, and when the molten salt is at a low liquid level, a large amount of residual liquid is difficult to be pumped out by the pump due to insufficient static pressure, resulting in a large amount of molten salt remaining.

[0003] Furthermore, molten salt thermal storage tanks typically conduct heat exchange inside the tank. This method requires the installation of heating units within the tank to heat the molten salt, as well as heat exchange pipes for heat exchange with the molten salt. When the cryogenic fluid enters the heat exchange pipes from the inlet, it exchanges heat with the high-temperature molten salt inside the tank, transforming the cryogenic fluid into a high-temperature, high-pressure fluid, which is then discharged from the outlet of the heat exchange pipes. This heat exchange method not only requires a complex arrangement of heat exchange pipes within the molten salt thermal storage tank, making installation difficult and maintenance challenging; it also relies on heating units such as electric heaters to maintain the molten salt temperature, resulting in low energy conversion efficiency and resource waste; and heating the molten salt within a closed tank can easily lead to localized overheating, material aging, or thermal stress concentration, posing safety hazards. Utility Model Content

[0004] To overcome the problems of single-layer tank structures lacking leakage protection mechanisms, severe heat loss, large amounts of molten salt remaining inside the tank that cannot be extracted, and the high installation complexity, high energy consumption, and safety hazards caused by built-in heat exchange methods in the aforementioned background technology, this utility model provides a molten salt thermal storage tank device. It adopts a double-layer tank structure with a protruding part occupying the bottom space inside the tank, and heat exchange occurs outside the tank. This improves the safety and insulation performance of the molten salt thermal storage tank, prevents molten salt leakage, reduces safety risks, reduces the residual molten salt rate inside the tank, and uses external heat exchange, resulting in a simple internal structure, avoiding safety hazards, and reducing heat exchange energy consumption.

[0005] The technical solution of this utility model is as follows: A molten salt thermal storage tank device includes an inner tank with a closed cavity for storing molten salt. The inner tank is located inside an outer cylinder, with a sandwich layer between them. The inner tank also has a protrusion that occupies the bottom space.

[0006] Compared with existing technologies, the beneficial effects of this technical solution are as follows: By configuring the molten salt thermal storage tank device as a double-layer tank structure with an inner tank and an outer cylinder, the safety and insulation performance of the molten salt thermal storage tank are improved, avoiding the problems of limited insulation performance and large heat loss of the single-layer tank structure used in the prior art. Furthermore, by setting an interlayer between the inner tank and the outer cylinder, the interlayer is used to collect the molten salt in the event of a leak in the inner tank, providing safety assurance and buying time and space for maintenance. This avoids the safety accident caused by the molten salt flowing directly out of the tank when a leak occurs, as is the case in the prior art. The protruding part can occupy the storage space at the bottom of the inner tank, that is, compress the storage space of the molten salt at the bottom of the inner tank. The inner tank can hold less molten salt to reach the height that the molten salt pump can draw in, and more molten salt can be drawn out of the tank, greatly reducing the amount of molten salt remaining in the tank.

[0007] Preferably, the inner storage tank has an inlet and an outlet, and the inlet and outlet are respectively connected to an inlet pipe and an outlet pipe, which extend outwards through the outer cylinder.

[0008] Its beneficial effects are as follows: the inlet pipe injects molten salt into the inner storage tank to replenish the molten salt, while the outlet pipe is used to draw out the molten salt from the inner storage tank.

[0009] More preferably, the inlet pipe is supplied with hot / cold molten salt; the inlet end of the outlet pipe extends to the bottom of the inner storage tank, and its outlet end extends outward and is connected to a molten salt pump, which is also connected to a molten salt heat exchanger or a molten salt heater.

[0010] Its beneficial effects are as follows: molten salt thermal storage tanks can store both hot and cold molten salt, and heat exchange can be achieved outside the tank, avoiding the need to install heat exchange pipes inside the tank. The structure is simpler, and installation and maintenance are easier. Moreover, heat exchange can be carried out fully and efficiently outside the tank through a dedicated molten salt heater or molten salt heat exchanger, improving energy conversion efficiency and better avoiding resource waste. Furthermore, heating the molten salt through the molten salt heater outside the tank results in more uniform heating of the molten salt, avoiding problems such as local overheating, material aging, or thermal stress concentration that could pose safety hazards.

[0011] In a further preferred embodiment, both the inlet and outlet are located on the top of the inner storage tank, and a temperature gauge, pressure gauge, liquid level sensor, and automatic pressure relief valve are also installed inside the tank top.

[0012] Its beneficial effects are as follows: thermometers and pressure gauges are used to monitor the temperature and pressure inside the tank in real time; radar level gauges are selected as the level sensors, which can achieve non-contact measurement of the liquid level and monitor the liquid level height inside the tank to avoid introducing too much molten salt; the automatic pressure relief valve can effectively control the pressure inside the tank. When the pressure inside the tank exceeds the set value, the automatic pressure relief valve can quickly open to release the excess pressure, which can effectively control the leakage of the inner storage tank and the pressure inside the tank, reduce the risk of molten salt leakage, and avoid serious safety accidents.

[0013] Preferably, the outer cylinder is sleeved and fixed around the inner storage tank; an annular cavity is left between the inner storage tank and the outer cylinder, and the interlayer is located in the annular cavity.

[0014] Its beneficial effects are: the inner tank and the outer cylinder can be stably connected together; the annular cavity formed between the inner tank and the outer cylinder is the interlayer, and the leaked molten salt flows into the annular cavity and will not continue to flow outward.

[0015] More preferably, the interlayer is equipped with a temperature gauge, a pressure gauge, and a liquid level sensor, all of which are electrically connected to the alarm.

[0016] Its beneficial effects are as follows: when the inner storage tank leaks, the temperature, pressure and liquid level in the jacket will change. When the set values ​​of each sensor are reached, the alarm will be triggered and the alarm sound will remind the staff to deal with it in time.

[0017] Preferably, the inner tank and the outer cylinder are mounted on a foundation, wherein the bottom plate of the inner tank extends to the bottom of the outer cylinder and is fixedly connected thereto.

[0018] Its beneficial effects are: this structure allows the molten salt thermal storage tank to be firmly fixed to the foundation, and forms a closed structure between the interlayer and the inner tank.

[0019] Preferably, the protrusion is fixed in the middle of the bottom plate surface of the inner storage tank, and its circumferential direction is a sloping or curved surface structure, gradually converging towards the center from the bottom upwards; the protrusion is made of high-temperature resistant castable material.

[0020] Its advantages are as follows: this design can further expand the space occupied by the protrusion at the bottom of the inner tank, and the gradually decreasing area occupied above the bottom of the protrusion also avoids excessive occupation of the inner tank space, thus significantly reducing its storage capacity. The protrusion is made of high-temperature resistant castable materials, such as refractory bricks, concrete, and ceramic materials, which can withstand the high-temperature environment inside the inner tank without melting.

[0021] More preferably, the outer cylinder circumferentially and the top surface of the inner storage tank are covered with an insulation layer, which is made of aerogel composite material.

[0022] Its beneficial effects are: the insulation layer made of this aerogel composite material has good thermal insulation performance, which can significantly reduce the heat loss of molten salt thermal storage tanks and improve the utilization rate of thermal energy.

[0023] Preferably, the bottom of the side walls of the inner tank and the outer cylinder are respectively connected to discharge pipes; the discharge pipe of the inner tank passes through the interlayer and exits the outer cylinder.

[0024] Its beneficial effects are as follows: when the inner storage tank leaks or when it is necessary to discharge the remaining molten salt in the molten salt storage tank, the discharge pipe can be opened, and the molten salt in the inner storage tank flows out from the discharge pipe connected to the inner storage tank, which is conducive to the discharge and maintenance of molten salt. Molten salt that leaks into the interlayer is discharged from the discharge pipe connected to the interlayer, so that the molten salt can be discharged from the interlayer in a controlled and orderly manner in the event of a leakage accident. Attached Figure Description

[0025] This utility model will be described with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0026] Reference numerals: Inner tank 1, Inlet 11, Outlet 12, Inlet pipe 13, Outlet pipe 14, Molten salt pump 15, Tank top 16, Bottom plate 17, Discharge pipe 18, Enclosed cavity 19, Outer cylinder 2, Insulation layer 21, Interlayer 3, Protrusion 4, Foundation 5. Detailed Implementation To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] Example 1: As Figure 1 The molten salt thermal storage tank device shown includes an inner tank 1, which may be a hollow cylindrical structure. The inner tank 1 has a closed cavity 19 inside, which is used to store molten salt in a liquid state. The inner tank 1 is set inside the outer cylinder 2 of the outer shell. The structure of the outer cylinder 2 is matched with the inner tank 1, and a sandwich 3 is provided between the two. When the tank wall of the inner tank 1 is cracked or the weld fails, the leaked molten salt can automatically flow into the sandwich 3. The inner tank 1 also has a protrusion 4 occupying the bottom space, which is fixed to the surface of the bottom plate 17 of the inner tank 1.

[0028] By configuring the molten salt thermal storage tank device as a double-layer tank structure with an inner tank 1 and an outer cylinder 2, the safety and insulation performance of the molten salt thermal storage tank are improved, avoiding the problem of limited insulation performance and large heat loss of the single-layer tank structure used in the prior art. Furthermore, by setting an interlayer 3 between the inner tank 1 and the outer cylinder 2, the interlayer 3 is used to collect the molten salt in the event of a leak in the inner tank 1, providing safety assurance and buying time and space for maintenance. This avoids the situation in the prior art where the molten salt would flow directly out of the tank and cause a safety accident when the tank leaks. The protrusion 4 can occupy the bottom space of the inner tank 1, that is, compress the storage space of the molten salt at the bottom of the inner tank 1. The inner tank 1 can reach the height that the molten salt pump 15 can draw in with a smaller amount of molten salt, and more molten salt in the tank can be drawn out, greatly reducing the amount of molten salt remaining in the tank.

[0029] Example 2: Based on Example 1, a preferred design is adopted. The inner storage tank 1 has an inlet 11 and an outlet 12. The inlet 11 and outlet 12 are respectively fixedly connected to an inlet pipe 13 and an outlet pipe 14 through pipe fittings. One end of the inlet pipe 13 and the outlet pipe 14 communicates with the interior of the inner storage tank 1, and the other end extends out of the inner storage tank 1. The inlet pipe 13 injects molten salt into the inner storage tank 1 to replenish the molten salt, and the outlet pipe 14 is used to draw out the molten salt in the inner storage tank 1.

[0030] Specifically, hot or cold molten salt is introduced through the inlet pipe 13, and the inlet end of the outlet pipe 14 extends vertically downwards to the bottom of the inner storage tank 1. When the inlet end 11 is submerged in the molten salt, the molten salt can be drawn out. Its outlet end extends outwards into the outer cylinder 2 and is connected to a molten salt pump 15. The molten salt pump 15 can deliver high-temperature fluids up to 460°C. The molten salt pump 15 is also connected to a molten salt heat exchanger or a molten salt heater. The temperature of the cold molten salt is around 220°C, and it can flow into or out of the inner storage tank 1 in a liquid state. The temperature of the hot molten salt is around 425°C. When hot molten salt is introduced through the inlet pipe 13, the molten salt pump 15 is connected to the molten salt heat exchanger, which can heat the medium inside the molten salt heat exchanger, making full use of the heat in the hot molten salt and improving the heat exchange efficiency. When cold molten salt is introduced through the inlet pipe 13, the molten salt pump 15 is connected to the molten salt heater, which heats the molten salt more evenly, further improving the heat exchange efficiency. Therefore, molten salt thermal storage tanks can store both hot and cold molten salt, and heat exchange can be achieved outside the tank, avoiding the need to install heat exchange pipes inside the tank. The structure is simpler, and installation and maintenance are easier. Moreover, heat exchange is carried out outside the tank through a dedicated molten salt heater or molten salt heat exchanger, which can achieve full and efficient heat exchange, improve energy conversion efficiency, and better avoid resource waste. Furthermore, heating the molten salt through the external molten salt heater ensures more uniform heating of the molten salt, avoiding problems such as local overheating, material aging, or thermal stress concentration that could pose safety hazards.

[0031] Preferably, both the inlet 11 and the outlet 12 are located at the top 16 of the inner storage tank 1. Molten salt flows into or is drawn out of the inner storage tank 1 from the top 16. The top 16 is also equipped with a thermometer, a pressure gauge, a level sensor, and an automatic pressure relief valve. The thermometer and pressure gauge are used to monitor the temperature and pressure inside the tank in real time. The level sensor is a radar level gauge, which can achieve non-contact measurement of the liquid level and is used to monitor the liquid level height inside the tank, preventing excessive molten salt from being introduced. The automatic pressure relief valve can effectively control the pressure inside the tank. When the pressure inside the tank exceeds the set value, the automatic pressure relief valve can quickly open to release the excess pressure, effectively controlling leakage and pressure inside the inner storage tank 1, reducing the risk of molten salt leakage, and preventing serious safety accidents.

[0032] Example 3: Based on Example 1, the inner storage tank 1 and the outer cylinder 2 are optimized. The outer cylinder 2 is fixed around the inner storage tank 1, and the top of the outer cylinder 2 extends towards the center and is welded and fixed around the tank wall of the inner storage tank 1 to ensure the stability of the connection between the two. An annular cavity is left between the inner storage tank 1 and the outer cylinder 2, and the interlayer 3 is located in the annular cavity. That is, the annular cavity formed between the inner storage tank 1 and the outer cylinder 2 is the interlayer 3. The leaked molten salt flows into the annular cavity and will not continue to flow outward.

[0033] Preferably, the interlayer 3 is equipped with a thermometer, a pressure gauge, and a liquid level sensor, all of which are electrically connected to the alarm. The thermometer and pressure gauge are used to monitor the temperature and pressure inside the interlayer 3 in real time, while the liquid level sensor is used to monitor the liquid level inside the interlayer 3. Once the inner storage tank 1 leaks, the temperature, pressure, and liquid level inside the interlayer 3 will change. When the set values ​​of each sensor are reached, the alarm will be triggered, and the alarm will sound to remind personnel to handle the situation promptly.

[0034] Example 4: Based on Example 1, the inner storage tank 1 and outer cylinder 2 are optimized. The inner storage tank 1 and outer cylinder 2 are installed on a foundation 5, which is the installation location for the entire molten salt thermal storage tank, such as a ground foundation. The bottom surface of the inner storage tank 1 is welded to the bottom plate 17 of the inner storage tank 1. The edge of the bottom plate 17 of the inner storage tank 1 extends outward to the bottom of the outer cylinder 2. The bottom surface of the outer cylinder 2 is also welded to the bottom plate 17. The bottom surface of the bottom plate 17 of the inner storage tank 1 is then fixedly connected to the foundation 5. This structure allows the entire molten salt thermal storage tank to be firmly fixed to the foundation 5, and forms a closed structure between the interior of the interlayer 3 and the interior of the inner storage tank 1.

[0035] Example 5: Based on Example 1, the protrusion 4 is optimized. The protrusion 4 is fixed in the middle of the bottom plate 17 of the inner storage tank 1. Its circumferential direction is a sloping or curved surface structure, gradually converging towards the center from the bottom upwards. It can be a frustum, a semi-ellipsoid, or a hemisphere structure. This design can further expand the space occupied by the protrusion 4 at the bottom of the inner storage tank 1, and the area occupied by the protrusion 4 above the bottom gradually decreases, which also avoids occupying too much space in the inner storage tank 1, thus significantly reducing its storage capacity. The protrusion 4 is made of high-temperature resistant castable material, such as refractory bricks, concrete, ceramic materials, etc., which can withstand the high-temperature environment inside the inner storage tank 1 without melting.

[0036] Preferably, the outer circumferential surface of the outer cylinder 2 and the top 16 surface of the inner storage tank 1 are covered with a heat insulation layer 21. The heat insulation layer 21 is made of aerogel composite material. The heat insulation layer 21 made of this aerogel composite material has good heat insulation performance, which can significantly reduce the heat loss of the molten salt heat storage tank and improve the utilization rate of thermal energy.

[0037] Example 5: Based on Example 1, the storage tank and outer cylinder 2 are optimized. The bottom of the side walls of the inner storage tank 1 and the outer cylinder 2 are respectively connected to discharge pipes 18. The discharge pipe 18 of the inner storage tank 1 passes through the interlayer 3 and exits through the outer cylinder 2 and the insulation layer 21 covering the surface of the outer cylinder 2. When the inner storage tank 1 leaks or when it is necessary to discharge the remaining molten salt in the molten salt storage tank, the discharge pipe 18 can be opened. The molten salt in the inner storage tank 1 flows out from the discharge pipe 18 connected to the inner storage tank 1, which is beneficial for the discharge and maintenance of the molten salt. Molten salt that leaks into the interlayer 3 is discharged from the discharge pipe 18 connected to the interlayer 3, so that the molten salt can be discharged from the interlayer 3 in a controllable and orderly manner in the event of a leak.

[0038] The above embodiments merely illustrate specific implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the technical solution of this application, and these all fall within the scope of protection of this application.

Claims

1. A molten salt thermal storage tank device, characterized in that: It includes an inner storage tank (1), which has a closed cavity (19) for storing molten salt. The inner storage tank (1) is located inside the outer cylinder (2), and there is a sandwich layer (3) between the two. The inner storage tank (1) also has a protrusion (4) that occupies the bottom space.

2. The molten salt thermal storage tank device according to claim 1, characterized in that: The inner storage tank (1) has an inlet (11) and an outlet (12). The inlet (11) and the outlet (12) are respectively connected to an inlet pipe (13) and an outlet pipe (14). The inlet pipe (13) and the outlet pipe (14) extend outwards through the outer cylinder (2).

3. The molten salt thermal storage tank device according to claim 2, characterized in that: The inlet pipe (13) is supplied with hot / cold molten salt; the inlet end of the outlet pipe (14) extends to the bottom of the inner storage tank (1), and its outlet end extends outward and is connected to a molten salt pump (15), which is also connected to a molten salt heat exchanger or a molten salt heater.

4. The molten salt thermal storage tank device according to claim 2, characterized in that: The inlet (11) and outlet (12) are both located on the top (16) of the inner storage tank (1). The top (16) is also equipped with a thermometer, a pressure gauge, a liquid level sensor and an automatic pressure relief valve.

5. The molten salt thermal storage tank device according to claim 1, characterized in that: The outer cylinder (2) is sleeved and fixed around the inner storage tank (1); an annular cavity is left between the inner storage tank (1) and the outer cylinder (2), and the interlayer (3) is located in the annular cavity.

6. A molten salt thermal storage tank device according to claim 1 or claim 5, characterized in that: The interlayer (3) is equipped with a thermometer, a pressure gauge and a liquid level sensor, all of which are electrically connected to the alarm.

7. The molten salt thermal storage tank device according to claim 1, characterized in that: The inner tank (1) and the outer cylinder (2) are installed on the foundation (5), wherein the bottom plate (17) of the inner tank (1) extends to the bottom of the outer cylinder (2) and is fixedly connected thereto.

8. The molten salt thermal storage tank device according to claim 1, characterized in that: The protrusion (4) is fixed in the middle of the bottom plate (17) of the inner storage tank (1), and its circumferential direction is a sloping or curved surface structure, and gradually converges towards the center from the bottom upward; the protrusion (4) is made of high temperature resistant castable material.

9. A molten salt thermal storage tank device according to claim 1 or claim 8, characterized in that: The outer cylinder (2) and the top (16) of the inner storage tank (1) are covered with a heat insulation layer (21), which is made of aerogel composite material.

10. A molten salt thermal storage tank device according to claim 1, characterized in that: The inner tank (1) and the outer cylinder (2) are respectively connected to the bottom of the side wall of the inner tank (1) and the outer cylinder (2); the discharge pipe (18) of the inner tank (1) passes through the interlayer (3) and out of the outer cylinder (2).

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