Molten salt storage tank device

Abstract

The invention relates to the technical field of fused salt heat storage, and provides a fused salt storage tank device which comprises a tank body, the tank body internally comprises a first area and a second area, and the second area is the bottom area in the tank body and / or the area, close to the axis of the tank body, in the tank body; the first area is the other area except the second area in the tank body, a fused salt heat storage material is arranged in the first area, and a non-fused salt heat storage material is arranged in at least part of the second area or the second area is in a vacant state; the heating device is inserted into the fused salt heat storage material in the first area in the vertical direction, and the heating device is used for heating the fused salt heat storage material. According to the fused salt storage tank device, the fused salt located in the area with the low utilization rate in an existing fused salt storage tank device is replaced with the non-fused salt heat storage material or the area is vacant, the use amount of the fused salt is reduced, and the investment cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of molten salt heat storage, and in particular to a molten salt storage tank device. Background Art

[0002] At present, there is a molten salt storage tank device, which includes a molten salt tank, an electric heating unit and a heat exchange pipe. The molten salt tank is filled with molten salt. The electric heating unit is inserted into the molten salt in the tank from the top of the molten salt tank. The electric heating unit is used to heat the molten salt. The heat exchange pipe includes an inlet near the bottom of the molten salt tank and an outlet near the top of the molten salt tank. When the low-temperature fluid enters the heat exchange pipe from the inlet, heat exchange occurs with the high-temperature molten salt in the tank through the heat exchange pipe, thereby converting the low-temperature fluid into a high-temperature and high-pressure fluid and discharging it from the outlet of the heat exchange pipe.

[0003] When the molten salt storage tank device is storing heat, the electric heating unit heats the molten salt to melt, and the density of the molten salt decreases as the temperature rises. The higher the temperature of the molten salt, the larger the volume and the smaller the density. As the heating process continues, the molten salt with higher temperature and lower density will rise, while the molten salt with lower temperature and higher density will sink. When the upper molten salt is heated to the highest operating temperature, the electric heating unit stops working, but at this time the temperature of the molten salt in the lower part of the tank is still relatively low, and the heat storage capacity of the molten salt in the lower part of the tank is not fully utilized, resulting in cost waste.

[0004] When the molten salt storage tank device releases heat, the water enters from the bottom and exits from the top. The heat exchange pipes are preheating section, boiling section and superheating section from bottom to top. The heat transfer coefficient, heat transfer temperature difference and heat transfer amount of the preheating section + boiling section are significantly higher than those of the superheating section. Therefore, the temperature drop rate of the molten salt in the lower part of the molten salt tank is higher than that of the upper part. The overall temperature distribution of the molten salt in the tank is characterized by being low at the bottom and high at the top. Since the heat exchange pipes are arranged around the periphery of the molten salt, the utilization rate of the molten salt (outer layer molten salt) close to the heat exchange pipes is higher when releasing heat, while the heat release capacity of the molten salt (core layer molten salt) far away from the heat exchange pipes is not fully utilized, resulting in cost waste. Summary of the invention

[0005] In order to solve the above problems, the present application provides a molten salt storage tank device and a molten salt heat storage system, which are cleverly designed and simple in structure. The present application reduces the use of molten salt and reduces the investment cost by replacing the molten salt in the low-utilization area of ​​the existing molten salt storage tank device with a non-molten salt heat storage material or leaving the area vacant. The technical solution adopted by the present application is as follows:

[0006] A molten salt storage tank device, comprising:

[0007] A tank body, wherein the tank body comprises a first area and a second area, the second area being the bottom area of ​​the tank body and / or the area near the axis of the tank body, the first area being the other area of ​​the tank body except the second area, a molten salt heat storage material is arranged in the first area, and a non-molten salt heat storage material is arranged in at least part of the second area or is in a vacant state; a heating device, wherein the heating device is inserted into the molten salt heat storage material in the first area in a vertical direction, and the heating device is used to directly heat the molten salt heat storage material.

[0008] By replacing the molten salt in the low-utilization area of ​​the existing molten salt storage tank device with non-molten salt heat storage materials or leaving the area vacant, the use of molten salt heat storage materials is reduced and the investment cost is reduced.

[0009] In some embodiments, the second region is a bottom region in the tank body, and the second region is filled with the non-molten salt heat storage material.

[0010] The bottom area inside the tank body is set as the second area, and the non-molten salt heat storage material can be directly placed on the bottom of the tank body. The inner wall and the bottom shell of the tank body restrain the non-molten salt heat storage material. There is no need to take other restraint measures for the non-molten salt heat storage material, and there is no need to set isolation measures between the second area and the first area. The molten salt heat storage material in the first area can be in direct contact with the non-molten salt heat storage material in the second area. This method is easy to implement.

[0011] In some embodiments, the molten salt storage tank device also includes a heat transfer tube, which is disposed inside the tank body and coaxially arranged with the tank body, the upper and lower ends of the heat transfer tube are closed, the inside of the heat transfer tube is the second area, and the outside of the heat transfer tube is the first area.

[0012] By setting up the heat transfer tube, in addition to reducing the use of molten salt heat storage materials and reducing investment costs, the heat transfer tube plays a role in heat conduction. The heat transfer tube can be used to transfer the heat of the molten salt heat storage material located at a high position in the first area to the molten salt heat storage material located at a low position in the first area, thereby improving the uniformity of the temperature distribution of the molten salt heat storage material in the height direction in the first area. At the same time, when non-molten salt heat storage materials are set in the heat transfer tube, the heat transfer tube will form a constraint on the non-molten salt heat storage material and limit the non-molten salt heat storage material in the second area. When there is a vacancy in the heat transfer tube, that is, when the heat transfer tube is not completely occupied by the non-molten salt heat storage material, the vacant area in the heat transfer tube will enhance the heat conduction effect of the heat transfer tube through radiation convection.

[0013] In some embodiments, the heat transfer tube is cylindrical, the interior of the heat transfer tube is completely empty or at least part of the heat transfer tube is provided with the non-molten salt heat storage material. The heat transfer tube is set to be cylindrical, which has a simple shape and is easy to process and manufacture.

[0014] In some embodiments, a fixing device is provided on the bottom surface of the tank body, and the heat transfer tube is inserted into the fixing device. By providing the fixing device, the stability of the heat transfer tube can be ensured and the heat transfer tube can be prevented from tipping over.

[0015] In some embodiments, the lower portion of the heat transfer tube is trumpet-shaped, and the lower portion of the heat transfer tube covers the bottom area in the tank body. The non-molten salt heat storage material is provided in at least the bottom area of ​​the heat transfer tube.

[0016] By setting the lower part of the heat transfer tube to be trumpet-shaped, the use of more molten salt heat storage materials can be reduced compared to a cylindrical heat transfer tube, and more investment costs can be reduced. In addition, the trumpet-shaped lower part of the heat transfer tube can improve the stability of the heat transfer tube and reduce the risk of the heat transfer tube tipping over. In addition, when a non-molten salt heat storage material is provided in the heat transfer tube, because the lower space of the heat transfer tube gradually becomes larger, that is to say, within the same height range, the closer to the bottom of the heat transfer tube, the more non-molten salt heat storage materials can be placed, and the more non-molten salt heat storage materials can supplement (provide) more heat for the molten salt heat storage materials near the same height. Whether it is when the molten salt storage tank device is storing heat or when the molten salt storage tank device is releasing heat, in order to improve the uniformity of the temperature distribution of the molten salt heat storage material in the height direction in the first region, it is also necessary to supplement (provide) more heat to the molten salt heat storage material located at a lower position.

[0017] In some embodiments, a plurality of heat-conducting fins are provided around the outer circumference of the heat transfer tube.

[0018] By arranging heat-conducting fins outside the heat transfer tube, the heat-conducting fins are immersed in the molten salt heat storage material in the first area. Compared with the heat transfer tube without heat-conducting fins, the whole formed by the heat-conducting fins and the heat transfer tube increases the heat transfer area, which is not only beneficial for quickly transferring the heat of the molten salt heat storage material located at a high position in the first area to the molten salt heat storage material located at a low position in the first area, but also when non-molten salt heat storage material is arranged in the heat transfer tube, it is also beneficial for quickly transferring the heat of the non-molten salt heat storage material to the molten salt heat storage material, thereby improving the thermal conductivity efficiency.

[0019] In some embodiments, a plurality of heat-conducting rods are disposed on the outer wall of the heat transfer tube, the plurality of heat-conducting rods are perpendicular to the axis of the heat transfer tube and the plurality of heat-conducting rods are distributed radially as a whole.

[0020] By setting up the heat-conducting rod, the heat-conducting rod is used to strengthen the heat transfer between the core molten salt (molten salt close to the heat transfer tube) and the outer molten salt (molten salt close to the inner wall of the tank). Compared with the technical solution without the heat-conducting rod, when the temperature of the outer molten salt drops due to the heat exchange of the heat exchange pipe, the heat of the core molten salt can be quickly transferred to the outer molten salt through the heat-conducting rod, that is, the core molten salt can quickly supplement the heat of the outer molten salt, thereby improving the utilization of the heat release capacity of the core molten salt.

[0021] In some embodiments, the second region is cylindrical, the second region is coaxially arranged with the tank body, the first region surrounds the outer circumference of the second region, and the second region is filled with the non-molten salt heat storage material.

[0022] In some embodiments, an electric heating component is provided in the heat transfer cylinder, and the electric heating component is used to heat the non-molten salt heat storage material.

[0023] By arranging an electric heating component in the heat transfer cylinder, the electric heating component can heat the non-molten salt heat storage material and store heat, and the overall heat storage capacity of the molten salt storage tank is not reduced, while the cost of the heat storage material is reduced.

[0024] On the other hand, the present application provides a molten salt heat storage system, which adopts the aforementioned molten salt storage tank device.

[0025] The present application provides a molten salt storage tank device and a molten salt heat storage system, which has at least one of the following beneficial effects:

[0026] 1. The present application provides a molten salt storage tank device, which reduces the usage of molten salt heat storage materials and reduces investment costs by replacing the molten salt in the low-utilization area of ​​the existing molten salt storage tank device with non-molten salt heat storage materials or leaving the area vacant.

[0027] 2. The present application provides a molten salt storage tank device, in which the bottom area inside the tank body is set as the second area, and the non-molten salt heat storage material can be directly placed on the bottom of the tank body. The inner wall and the bottom shell of the tank body restrain the non-molten salt heat storage material, and there is no need to take other restraint measures for the non-molten salt heat storage material. There is no need to set isolation measures between the second area and the first area. The molten salt heat storage material in the first area can be in direct contact with the non-molten salt heat storage material in the second area. This method is easy to implement.

[0028] 3. The present application provides a molten salt storage tank device. By setting a heat transfer tube, in addition to reducing the use of molten salt heat storage materials and reducing investment costs, the heat transfer tube plays a role in heat conduction. The heat transfer tube can be used to transfer the heat of the molten salt heat storage material located at a high position in the first area to the molten salt heat storage material located at a low position in the first area, thereby improving the uniformity of the temperature distribution of the molten salt heat storage material in the height direction in the first area. At the same time, when a non-molten salt heat storage material is set in the heat transfer tube, the heat transfer tube will form a constraint on the non-molten salt heat storage material and limit the non-molten salt heat storage material in the second area. When there is a vacancy in the heat transfer tube, that is, when the heat transfer tube is not completely occupied by the non-molten salt heat storage material, the vacant area in the heat transfer tube will enhance the heat conduction effect of the heat transfer tube through radiation convection.

[0029] 4. The molten salt storage tank device provided in the present application sets the heat transfer tube into a cylindrical shape, which has a simple shape and is easy to process and manufacture.

[0030] 5. The molten salt storage tank device provided in the present application can ensure the stability of the heat transfer tube and prevent the heat transfer tube from tipping over by setting a fixing device.

[0031] 6. A molten salt storage tank device provided by the present application, by setting the lower part of the heat transfer tube to a trumpet shape, can reduce the use of more molten salt heat storage materials and reduce more investment costs compared to a cylindrical heat transfer tube. In addition, the trumpet shape of the lower part of the heat transfer tube can improve the stability of the heat transfer tube and reduce the risk of the heat transfer tube tipping over. In addition, when a non-molten salt heat storage material is provided in the heat transfer tube, because the lower space of the heat transfer tube gradually becomes larger, that is to say, within the same height range, the closer to the bottom of the heat transfer tube, the more non-molten salt heat storage materials can be placed, and the non-molten salt heat storage materials will not flow, the temperature difference is lower, and the more non-molten salt heat storage materials can supplement (provide) more heat for the molten salt heat storage materials near the same height. Whether it is when the molten salt storage tank device is storing heat or when the molten salt storage tank device is releasing heat, in order to improve the uniformity of the temperature distribution of the molten salt heat storage material in the height direction in the first region, it is also necessary to supplement (provide) more heat to the molten salt heat storage material located at a lower position.

[0032] 7. The present application provides a molten salt storage tank device, in which heat-conducting fins are arranged outside the heat transfer tube, and the heat-conducting fins are immersed in the molten salt heat storage material in the first area. Compared with the heat transfer tube without heat-conducting fins, the whole formed by the heat-conducting fins and the heat transfer tube increases the heat transfer area. This is not only beneficial for quickly transferring the heat of the molten salt heat storage material located at a high position in the first area to the molten salt heat storage material located at a low position in the first area, but also beneficial for quickly transferring the heat of the non-molten salt heat storage material to the molten salt heat storage material when a non-molten salt heat storage material is arranged in the heat transfer tube, thereby improving the thermal conductivity efficiency.

[0033] 8. The present application provides a molten salt storage tank device, which is provided with a heat-conducting rod, and the heat-conducting rod is used to strengthen the heat transfer between the core molten salt (molten salt close to the heat transfer tube) and the outer molten salt (molten salt close to the inner wall of the tank). Compared with the technical solution without a heat-conducting rod, when the temperature of the outer molten salt decreases due to the heat exchange of the heat exchange pipe, the heat of the core molten salt can be quickly transferred to the outer molten salt through the heat-conducting rod, that is, the core molten salt can quickly supplement the heat of the outer molten salt, thereby improving the utilization of the heat release capacity of the core molten salt.

[0034] 9. The present application provides a molten salt storage tank device, which arranges an electric heating component in the heat transfer tube. The electric heating component can heat the non-molten salt heat storage material and store heat. The overall heat storage capacity of the molten salt storage tank is not reduced, while the cost of the heat storage material is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following will explain the preferred implementation mode in a clear and understandable manner in conjunction with the accompanying drawings to further illustrate the above characteristics, technical features, advantages and implementation methods of a molten salt storage tank device and a molten salt heat storage system:

[0036] Figure 1 is a schematic diagram of the overall structure of an embodiment when the second area is the bottom area inside the tank body;

[0037] Figure 2 It is a schematic diagram of the overall structure of an embodiment in which the heat transfer tube is cylindrical and has a hollow interior;

[0038] Figure 3 It is a schematic diagram of the overall structure of an embodiment in which the heat transfer cylinder is cylindrical and a non-molten salt heat storage material is arranged in a part of the internal area;

[0039] Figure 4 It is a schematic diagram of the overall structure of an embodiment in which the heat transfer cylinder is cylindrical and non-molten salt heat storage materials are arranged in the entire internal area;

[0040] Figure 5 It is a schematic diagram of the overall structure of an embodiment in which the heat transfer tube is cylindrical and is provided with a fixing device;

[0041] Figure 6 It is a schematic diagram of the overall structure of an embodiment in which the lower part of the heat transfer tube is trumpet-shaped and a non-molten salt heat storage material is arranged in the bottom area inside the heat transfer tube;

[0042] Figure 7 It is a schematic diagram of the overall structure of an embodiment in which the lower portion of the heat transfer tube is trumpet-shaped and non-molten salt heat storage materials are arranged in the entire area inside the heat transfer tube;

[0043] Figure 8 is a schematic diagram of the overall structure of an embodiment in which the second region is cylindrical and the second region is entirely provided with non-molten salt heat storage material;

[0044] Fig. 9 It is a schematic diagram of the overall structure of an embodiment in which a heat transfer rod is arranged on the outer wall of the heat transfer cylinder;

[0045] Fig.10 It is a schematic diagram of the overall structure of another embodiment in which the lower portion of the heat transfer tube is trumpet-shaped and a non-molten salt heat storage material is disposed in the bottom area inside the heat transfer tube;

[0046] Fig.11 This is a schematic diagram of the overall structure of another embodiment in which the lower portion of the heat transfer tube is trumpet-shaped and a non-molten salt heat storage material is disposed in the bottom area inside the heat transfer tube.

[0047] Description of Figure Numbers:

[0048] Tank body 1, first area 2, second area 3, heating device 4, heat transfer tube 5, fixing device 6, non-molten salt heat storage material 7, heat conducting ribs 8, heat conducting rod 9, heating wire 10. DETAILED DESCRIPTION

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0050] In order to simplify the drawings, only the parts related to the present application are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0051] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0052] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0054] refer to Figure 1-Figure 9 The present application provides a molten salt storage tank device, comprising: a tank body 1, wherein the tank body 1 comprises a first area 2 and a second area 3, wherein the second area 3 is a bottom area within the tank body 1 and / or an area near the axis of the tank body 1 within the tank body 1, and the first area 2 is other areas within the tank body 1 except the second area 3, wherein a molten salt heat storage material is provided in the first area 2, and a non-molten salt heat storage material 7 is provided in at least part of the area of ​​the second area 3 or is in a vacant state; and a heating device 4, wherein the heating device 4 is inserted into the molten salt heat storage material in the first area 2 along a vertical direction, and the heating device 4 is used to directly heat the molten salt heat storage material.

[0055] It is understandable that when the molten salt storage tank device is storing heat, in addition to the molten salt heat storage material storing heat, when the non-molten salt heat storage material 7 is provided in the second area 3, the non-molten salt heat storage material 7 also stores heat. Similarly, when the molten salt storage tank device is releasing heat, in addition to the molten salt heat storage material releasing heat, the non-molten salt heat storage material 7 also releases heat. Specifically, the non-molten salt heat storage material 7 has a lower volume cost than the molten salt heat storage material. The non-molten salt heat storage material is solid. The non-molten salt heat storage material 7 will not melt after storing heat. Compared with the molten salt heat storage material, it will not flow, and the heat release is slower than that of the molten salt heat storage material. The non-molten salt heat storage material 7 is equivalent to a heat energy bag, which replenishes heat for the molten salt heat storage material close to it. The molten salt heat storage material mentioned in this application can be a molten salt formed by mixing 50% sodium nitrate and 50% potassium nitrate, or a molten salt formed by mixing 60% sodium nitrate and 40% potassium nitrate, or a low melting point molten salt (melting point as low as about 80°) disclosed in the patent with application number CN201911219662, or a multi-component mixed molten salt (melting point as low as 47.3°) disclosed in the patent with application number CN202311105206, or other types of molten salts. It is understandable that the molten salt heat storage material can be composed of one molten salt or a mixture of multiple molten salts. The non-molten salt heat storage material 7 is a solid heat storage medium, which can be ceramsite, metal block, corundum block, high aluminum block, dolomite block, ore, glass, gravel, sand, etc. It should be noted that the non-molten salt heat storage material 7 can also be heat storage bricks and concrete. The non-molten salt heat storage material 7 can be a combination of one or more of the above example materials.

[0056] It should be noted that the first area 2 and the second area 3 are only divisions of the space in the tank body 1. In a specific embodiment, there may be physical isolation between the two areas, or there may be no physical isolation. It is understandable that when the molten salt heat storage material is in direct contact with the non-molten salt heat storage material 7, the type of non-molten salt heat storage material 7 selected cannot produce a chemical reaction with the molten salt heat storage material.

[0057] It is worth noting that by replacing the molten salt in the low-utilization area of ​​the existing molten salt storage tank device with non-molten salt heat storage material 7 or leaving the area vacant, the usage of molten salt heat storage material is reduced and the investment cost is reduced.

[0058] refer to Figure 1 In one embodiment, the second region 3 is the bottom region in the tank body 1, and the second region 3 is filled with a non-molten salt heat storage material 7. The bottom region in the tank body 1 is set as the second region 3, and the non-molten salt heat storage material 7 can be directly placed at the bottom of the tank body 1. The inner wall and the bottom shell of the tank body 1 form a constraint on the non-molten salt heat storage material 7, and no other constraint measures are required for the non-molten salt heat storage material 7. There is no need to set isolation measures between the second region 3 and the first region 2. The molten salt heat storage material in the first region 2 can be in direct contact with the non-molten salt heat storage material 7 in the second region 3. This method is easy to implement.

[0059] refer to Figure 2-Figure 7 , Fig. 9 In one embodiment, the molten salt storage tank device further includes a heat transfer tube 5, which is disposed in the tank body 1 and coaxially disposed with the tank body 1, the upper and lower ends of the heat transfer tube 5 are closed, the interior of the heat transfer tube 5 is the second region 3, and the exterior of the heat transfer tube 5 is the first region 2. By providing the heat transfer tube 5, in addition to reducing the amount of molten salt heat storage material used and reducing investment costs, the heat transfer tube 5 plays a role in heat conduction, and the heat transfer tube 5 can be used to conduct the heat of the molten salt heat storage material located at a high position in the first region 2 to the molten salt heat storage material located at a low position in the first region 2, thereby improving the uniformity of the temperature distribution of the molten salt heat storage material in the first region 2 in the height direction. At the same time, when a non-molten salt heat storage material 7 is provided in the heat transfer tube 5, the heat transfer tube 5 will restrain the non-molten salt heat storage material 7, and confine the non-molten salt heat storage material 7 in the second region 3. When there are gaps in the heat transfer tube 5, that is, when the heat transfer tube 5 is not completely occupied by the non-molten salt heat storage material 7, the gaps in the heat transfer tube 5 will enhance the heat conduction effect of the heat transfer tube 5 through radiation convection.

[0060] The heat transfer tube 5 can be made of metal material only, or a metal material with a thermal conductive coating provided on the surface. The thermal conductive coating can be graphene, high temperature resistant thermal conductive paint, etc. The heat transfer tube can also be made of other thermal conductive materials.

[0061] refer to Figure 2-Figure 5 , Fig. 9 In one embodiment, the heat transfer tube 5 is cylindrical, and the interior of the heat transfer tube 5 is completely empty or at least part of the heat transfer tube 5 is provided with non-molten salt heat storage material 7. The heat transfer tube 5 is set to be cylindrical, which has a simple shape and is easy to process and manufacture.

[0062] Specifically, the interior of the heat transfer tube 5 can be as follows Figure 2As shown, there is no non-molten salt heat storage material 7 inside, and the whole is in a vacant state; it can also be as shown in FIG. Figure 3 As shown, the non-molten salt heat storage material 7 is arranged in the area near the bottom of the heat transfer cylinder 5, while the area near the top is vacant; Figure 4 , Figure 5 As shown, the interior of the heat transfer cylinder 5 is entirely provided with non-molten salt heat storage material 7 .

[0063] refer to Figure 5 In one embodiment, a fixing device 6 is provided on the bottom surface of the tank body 1 , and the heat transfer tube 5 is inserted into the fixing device 6 . Figure 5 Figure A in the figure shows the state where the heat transfer tube 5 is not inserted into the fixing device 6. Figure 5 Figure B shows the state where the heat transfer tube 5 is inserted into the fixing device 6.

[0064] Specifically, the fixing device 6 is provided with a slot or a card slot adapted to the heat transfer tube 5, and the fixing device 6 is directly placed on the tank bottom without mechanical connection or welding with the tank bottom, so as to avoid damage to the original structure of the tank body 1 and prevent stress concentration on the tank bottom due to the setting of the fixing device 6. It can be understood that the fixing device 6 has a larger base or a larger span leg, and by setting the fixing device 6, the stability of the heat transfer tube 5 can be ensured and the heat transfer tube 5 can be prevented from tipping over.

[0065] refer to Figure 6 , Figure 7 , Fig.10 , Fig.11 In one embodiment, the lower portion of the heat transfer tube 5 is trumpet-shaped, and the lower portion of the heat transfer tube 5 covers the bottom area in the tank body 1. The heat transfer tube 5 is provided with a non-molten salt heat storage material 7 at least in the bottom area.

[0066] Specifically, the interior of the heat transfer tube 5 can be as follows Figure 6 , Fig.10 , Fig.11 As shown, the non-molten salt heat storage material 7 is arranged in the area near the bottom of the heat transfer cylinder 5, while the area near the top is vacant; Figure 7 As shown, the interior of the heat transfer cylinder 5 is entirely provided with non-molten salt heat storage material 7 .

[0067] In addition, the trumpet-shaped lower portion of the heat transfer tube 5 can be Figure 6 , Figure 7 , Fig.10 In other embodiments, the trumpet-shaped lower portion of the heat transfer tube 5 may be as shown in FIG. Fig.11 As in the embodiment of the present invention, a portion of the entire bottom area in the tank body 1 is covered.

[0068] It is worth noting that by setting the lower part of the heat transfer tube 5 to be trumpet-shaped, the use of more molten salt heat storage materials can be reduced compared to the cylindrical heat transfer tube 5, and the investment cost can be reduced. In addition, the trumpet-shaped lower part of the heat transfer tube 5 can improve the stability of the heat transfer tube 5 and reduce the risk of the heat transfer tube 5 tipping over. In addition, when the heat transfer tube 5 is provided with non-molten salt heat storage materials 7, because the lower space of the heat transfer tube 5 gradually becomes larger, that is, within the same height range, the closer to the bottom of the heat transfer tube 5, the more non-molten salt heat storage materials 7 can be placed, and the non-molten salt heat storage materials will not flow, the temperature difference is lower, and the more non-molten salt heat storage materials 7 can supplement (provide) more heat for the molten salt heat storage materials near the same height. Whether it is when the molten salt storage tank device is storing heat or when the molten salt storage tank device is releasing heat, in order to improve the uniformity of the temperature distribution of the molten salt heat storage materials in the height direction in the first area 2, it is also necessary to supplement (provide) more heat to the molten salt heat storage materials located at a lower position.

[0069] refer to Fig.10 , Fig.11 In one embodiment, an electric heating component is provided in the heat transfer tube 5, and the electric heating component is used to heat the non-molten salt heat storage material 7. Specifically, the electric heating component is preferably a heating wire 10. By providing the electric heating component in the heat transfer tube 5, the electric heating component can heat the non-molten salt heat storage material 7 and store heat, the overall heat storage capacity of the molten salt storage tank is not reduced, and the cost of the heat storage material is reduced. In other embodiments, a heating device 4 can be used to replace the heating wire 10 in the heat transfer tube 5. The heating wire 10 is preferably arranged in a flexible manner and can better adapt to the shape of the lower part of the heat transfer tube 5 to ensure the heating effect of the non-molten salt heat storage material 7.

[0070] Understandably, Fig.10 , Fig.11 These are just two exemplary specific embodiments of providing an electric heating component in the heat transfer tube 5. In other embodiments, an electric heating component may also be provided in the heat transfer tube, and the specific structural form of the heat transfer tube is not limited.

[0071] refer to Figure 2-Figure 4 , Figure 6 , Figure 7In one embodiment, a plurality of heat-conducting fins 8 are provided in the circumferential direction of the heat transfer tube 5. Specifically, the heat-conducting fins 8 extend along the height direction of the heat transfer tube 5 in accordance with the outer wall of the heat transfer tube 5. It can be understood that by providing the heat-conducting fins 8 outside the heat transfer tube 5, the heat-conducting fins 8 are immersed in the molten salt heat storage material in the first region 2. The heat-conducting fins 8 and the heat transfer tube 5 form a whole, which increases the heat transfer area compared to the heat transfer tube 5 without the heat-conducting fins 8. It is not only conducive to quickly conduct the heat of the molten salt heat storage material located at a high position in the first region 2 to the molten salt heat storage material located at a low position in the first region 2, but also when the non-molten salt heat storage material 7 is provided in the heat transfer tube 5, it is also conducive to quickly conduct the heat of the non-molten salt heat storage material 7 to the molten salt heat storage material, thereby improving the heat conduction efficiency.

[0072] refer to Fig. 9 In one embodiment, a plurality of heat-conducting rods 9 are disposed on the outer wall of the heat transfer tube 5. The plurality of heat-conducting rods 9 are perpendicular to the axis of the heat transfer tube 5 and are radially distributed as a whole.

[0073] It can be understood that by setting the heat-conducting rod 9, the heat-conducting rod 9 is used to strengthen the heat transfer between the core molten salt (molten salt close to the heat transfer tube 5) and the outer molten salt (molten salt close to the inner wall of the tank body 1). Compared with the technical solution without the heat-conducting rod 9, when the temperature of the outer molten salt decreases due to the heat exchange of the heat exchange pipe, the heat of the core molten salt can be quickly transferred to the outer molten salt through the heat-conducting rod 9, that is, the core molten salt can quickly supplement the heat to the outer molten salt, thereby improving the utilization of the heat release capacity of the core molten salt. It should be noted that when setting the heat-conducting rod 9, the heating device 4 needs to be avoided. Another point worth noting is that in a specific embodiment, only one of the heat-conducting ribs 8 and the heat-conducting rod 9 can be set, or the heat-conducting ribs 8 and the heat-conducting rod 9 can be set at the same time.

[0074] refer to Figure 8 In one embodiment, the second region 3 is cylindrical, the second region 3 is coaxially arranged with the tank body 1 , the first region 2 surrounds the outer periphery of the second region 3 , and the second region 3 is filled with non-molten salt heat storage material 7 .

[0075] Specifically, in this embodiment, the heat transfer tube 5 is not provided, and the non-molten salt heat storage material 7 is provided in a cylindrical shape by masonry, or can be formed into a cylindrical shape by using a metal mesh.

[0076] On the other hand, the present application provides a molten salt heat storage system, which adopts the aforementioned molten salt storage tank device. The specific structure of the molten salt storage tank device refers to the aforementioned embodiment. Since the present molten salt heat storage system adopts the technical solution of the aforementioned embodiment, it at least has the beneficial effects brought by the technical solution of the aforementioned embodiment, which will not be repeated here one by one.

[0077] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A molten salt storage tank device, characterized in that: include: A tank body, wherein the tank body comprises a first area and a second area, the second area is a bottom area of ​​the tank body and / or an area near the axis of the tank body, the first area is other areas of the tank body except the second area, a molten salt heat storage material is arranged in the first area, and a non-molten salt heat storage material is arranged in at least part of the second area or is vacant; A heating device is inserted into the molten salt heat storage material in the first region along a vertical direction, and the heating device is used to directly heat the molten salt heat storage material.

2. A molten salt storage tank device according to claim 1, characterized in that: The second region is a bottom region in the tank body, and the second region is filled with the non-molten salt heat storage material.

3. A molten salt storage tank device according to claim 1, characterized in that: It also includes a heat transfer tube, which is arranged in the tank body and coaxially with the tank body. The upper and lower ends of the heat transfer tube are closed, the inside of the heat transfer tube is the second area, and the outside of the heat transfer tube is the first area.

4. A molten salt storage tank device according to claim 3, characterized in that: The heat transfer tube is cylindrical, and the interior of the heat transfer tube is entirely empty or at least a portion of the heat transfer tube is provided with the non-molten salt heat storage material.

5. A molten salt storage tank device according to claim 4, characterized in that: A fixing device is provided on the bottom surface of the tank body, and the heat transfer tube is inserted into the fixing device.

6. A molten salt storage tank device according to claim 3, characterized in that: The lower portion of the heat transfer tube is trumpet-shaped and covers the bottom area in the tank body. The non-molten salt heat storage material is provided in at least the bottom area of ​​the heat transfer tube.

7. A molten salt storage tank device according to any one of claims 3 to 6, characterized in that: A plurality of heat-conducting fins are arranged in an circumferential direction on the outer circumference of the heat transfer cylinder.

8. A molten salt storage tank device according to any one of claims 3 to 6, characterized in that: A plurality of heat-conducting rods are arranged on the outer wall of the heat transfer tube, the plurality of heat-conducting rods are perpendicular to the axis of the heat transfer tube and the plurality of heat-conducting rods are distributed radially as a whole.

9. A molten salt storage tank device according to claim 1, characterized in that: The second region is cylindrical, the second region is coaxially arranged with the tank body, the first region surrounds the outer circumference of the second region, and the second region is filled with the non-molten salt heat storage material.

10. A molten salt storage tank device according to claim 6, characterized in that: An electric heating component is provided in the heat transfer cylinder, and the electric heating component is used to heat the non-molten salt heat storage material.

Images