Composite graphite phase change heat storage unit and tank-type phase change heat storage heat exchanger using it

Abstract

This utility model provides a composite graphite phase change heat storage unit and a tank-type phase change heat storage exchanger using the same. The heat storage unit achieves axial locking between the tank body and the tank cover through a keyed interlocking structure and matching axial locking components. This ensures good stability and sealing of the tank body and the tank cover, effectively preventing the PCM from expanding and overflowing after being heated. Furthermore, the heat storage unit is installed and fixed in the heat exchanger by suspension, allowing for flexible and varied arrangement. By adjusting the suspension angle and arrangement density, the flow field of the HTF can be adjusted, creating turbulence and improving heat exchange efficiency. The HTF fluid in the phase change heat storage exchanger flows and exchanges heat layer by layer in an S-shape, increasing the heat exchange time and improving the heat exchange efficiency.

Description

Technical Field

[0001] This utility model relates to the field of phase change heat storage heat exchanger technology, and in particular to a composite graphite phase change heat storage unit and a tank-type phase change heat storage heat exchanger using the same. Background Technology

[0002] Phase change energy storage devices utilize the property of phase change materials (PCMs) to absorb or release large amounts of heat during phase change to store and release thermal energy, and they have broad application prospects in energy storage and temperature control. Currently, the mainstream phase change energy storage devices are roughly divided into three categories: shell and tube type, packed bed type, and plate type; the corresponding heat storage units used are shell-and-tube type heat storage unit, bladder type heat storage unit, and plate type heat storage unit, respectively.

[0003] Chinese patent CN201710212021.3 discloses a high-temperature molten salt phase change heat storage and release device, which includes at least a heat storage unit and a heat storage tube array composed of multiple heat storage tubes. The heat storage unit has a gas inlet and outlet; the heat storage tube array is installed in the heat storage unit, and each heat storage tube contains a high-temperature phase change material with a freezing point higher than 750°C, utilizing the high-temperature phase change material to exchange heat with the gas entering the heat storage unit. One end of each heat storage tube is a blind tube, and the other end is sealed with a sealing cap to enclose the high-temperature phase change material.

[0004] However, this technical solution has the following shortcomings: the tank body and the tank cover are fixed by a plugging method, resulting in low stability of the connection between the two, easy loosening or even falling off of the tank cover, and poor sealing; in addition, it is unclear how multiple heat storage tubes are installed and fixed inside the heat storage unit. Summary of the Invention

[0005] One of the objectives of this invention is to address the shortcomings of existing technologies by providing a composite graphite phase change heat storage unit and a tank-type phase change heat storage exchanger using the same. The heat storage unit achieves axial locking between the tank body and the tank cover through a keyed interlocking structure and matching axial locking components. This ensures good stability and sealing of the tank body and the tank cover, effectively preventing the PCM from expanding and overflowing after being heated. Furthermore, the heat storage unit is installed and fixed in the heat exchanger by suspension, allowing for flexible and varied arrangement. By adjusting the suspension angle and arrangement density, the flow field of the HTF can be adjusted, turbulence can be generated, and heat exchange efficiency can be improved.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A composite graphite phase change thermal storage unit includes a tank body, a tank cover that matches and fits the tank body, and an axial locking member. The outer wall of the tank body at the tank opening has a radially protruding key A. The tank body has a circumferential area with and without key A, wherein the area without key A has a keyway A. The outer wall of the tank cover has a radially protruding key B. The tank cover has a circumferential area with and without key B, wherein the area without key B has a keyway B. Locking grooves are radially recessed on both key A and key B. After key B is fitted into keyway A and key A is fitted into keyway B, the axial locking member is fitted into the locking groove.

[0007] As an improvement, the key A is configured to be adapted to the size of the keyway B, and the key B is configured to be adapted to the size of the keyway A.

[0008] As an improvement, at least two keys A are distributed circumferentially along the can body, and a keyway A is formed between two adjacent keys A; at least two keys B are distributed circumferentially along the can lid, and a keyway B is formed between two adjacent can lids.

[0009] As an improvement, two of each of the keys A and B are provided.

[0010] As an improvement, the composite graphite phase change thermal storage unit uses graphite material and is coated with a ceramic coating on both the inner and outer surfaces.

[0011] As an improvement, the composite graphite phase change heat storage unit is configured as a cylindrical tank structure, and the axial locking member, key A, keyway A, key B and keyway B are matched and configured as an arc-shaped structure.

[0012] As an improvement, the composite graphite phase change heat storage unit is configured as a rectangular or elliptical tank structure, and the axial locking member, key A, keyway A, key B and keyway B are matched and configured as straight or arc-shaped structures.

[0013] As an improvement, the key B includes a first portion connected to the outer wall of the can lid and a second portion extending axially from the first portion along the can lid, wherein the second portion is fitted into the keyway A, and the locking groove is formed on the second portion.

[0014] As an improvement, the can lid includes a lid body with an outer diameter greater than the inner diameter of the can and an inner plug body connected to the bottom of the lid body with an outer diameter not greater than the inner diameter of the can, the inner plug body being fitted into the can body.

[0015] This utility model also provides a tank-type phase change heat storage heat exchanger, including a heat exchanger shell; and further including a composite graphite phase change heat storage unit as described above, wherein at least one layer of baffles is distributed axially inside the heat exchanger shell, and mounting holes are distributed on the baffles, and the composite graphite phase change heat storage unit is mounted on the mounting holes by key A and key B.

[0016] As an improvement, the diameter of the mounting hole is larger than the outer diameter of the can body and smaller than the outer diameters of keys A and B, so that the can body extends into the mounting hole until keys A and B are limited to outside the mounting hole.

[0017] As an improvement, the baffle plate is provided with a slit portion, and the baffle plate is provided with at least two layers with the slit portions being staggered layer by layer to guide the HTF fluid in the heat exchanger shell to flow and exchange heat in a spiral manner layer by layer.

[0018] As an improvement, the cut portions of the two adjacent layers of baffles are arranged 180° opposite each other to guide the HTF fluid in the heat exchanger shell to flow and exchange heat layer by layer in an S-shape.

[0019] As an improvement, a positioning rod assembly is also included, wherein multiple sets of the positioning rod assembly are distributed along the circumferential edge of the baffle plate, which positions and calibrates the installation angle of each layer of the baffle plate so that the cut-out portion is staggered layer by layer according to a set angle.

[0020] As an improvement, the positioning rod assembly includes an inner rod and a sleeve rod. The inner rod is disposed through the circumferential edge of the baffle plate to connect multiple baffle plates in series. The sleeve rod is sleeved on the inner rod between two adjacent baffle plates. The two axial ends of the sleeve rod abut against two adjacent baffle plates to fix and limit the axial distance between the two baffle plates.

[0021] As an improvement, the positioning rod assembly is provided in four sets along the circumferential edge of the baffle.

[0022] The beneficial effects of this utility model are as follows: (1) The heat storage unit in this utility model is provided with keys and keyways distributed in the circumferential direction on the tank opening and the tank cover. The tank body and the tank cover are engaged with each other by the keys and keyways and then axial locking is achieved by inserting an axial locking member into the key. This connection method makes the lid connection between the tank body and the tank cover stable enough, effectively preventing the tank cover from falling off, and the sealing performance is good, effectively preventing the PCM from expanding and overflowing after being heated.

[0023] (2) The heat storage unit in this utility model is made of graphite with a dense coating, which is suitable for harsh environments, including the corrosiveness of PCM, the corrosiveness of HTF, and a higher heat storage temperature range, thus possessing high temperature resistance, corrosion resistance and impermeability.

[0024] (3) The heat storage unit in this utility model is installed and fixed in the heat exchanger by suspension. The arrangement is flexible and varied. By adjusting the suspension angle and arrangement density, the flow field of HTF can be adjusted, turbulence can be formed, and the heat exchange efficiency can be improved. The positioning rod structure is set to position and calibrate the installation angle of the baffle plate so that the cut parts of each layer of baffle plate are staggered layer by layer according to the set angle.

[0025] (4) The phase change heat storage heat exchanger in this utility model has cut-out parts on the opposite sides of two adjacent layers of baffles, thereby guiding the HTF fluid in the heat exchanger shell to flow and exchange heat layer by layer in an S-shape, increasing the heat exchange time and improving the heat exchange efficiency. Attached Figure Description

[0026] Figure 1 This is an exploded view of the overall structure of the composite graphite phase change heat storage unit in this utility model; Figure 2 This is a schematic diagram of the connection structure between the tank body and the tank lid in this utility model; Figure 3 This is a schematic diagram of the structure of the can lid in this utility model; Figure 4 This is a cross-sectional view of the overall structure of the composite graphite phase change heat storage unit in this utility model; Figure 5 This is a cross-sectional view of the overall structure of the tank-type phase change heat storage heat exchanger of this utility model; Figure 6 This is a schematic diagram of the internal structure of the tank-type phase change heat exchanger of this utility model; Figure 7 This is a schematic diagram of the installation of the heat storage unit in the heat exchanger in this utility model; Figure 8 This is a diagram showing the HTF fluid flow path of the tank-type phase change heat exchanger in this utility model. Figure 9 This is a schematic diagram of the connection of the positioning rod assembly in this utility model. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] Example 1 like Figures 1-3 As shown, a composite graphite phase change heat storage unit includes a tank body 1, a tank cover 2 that matches and fits the tank body 1, and an axial locking member 3. The outer wall of the tank body 1 at the tank opening is radially protruded with a key A11, and the circumference of the tank body 1 includes an area with the key A11 and an area without the key A11, wherein the area without the key A11 is provided with a keyway A12. The outer wall of the tank cover 2 is radially protruded with a key B21, and the circumference of the tank cover 2 includes an area with the key B21 and an area without the key B21, wherein the area without the key B21 is provided with a keyway B22. Locking grooves 30 are radially recessed on the key A11 and key B21. After the key B21 is fitted into the keyway A12 and the key A11 is fitted into the keyway B22, the axial locking member 3 is fitted into the locking groove 30.

[0030] In this embodiment, the can body 1 and the can lid 2 form an axial locking structure through a keyway. Specifically, the outer wall of the can body 1 has a key A11 protruding radially, and the area without key A11 has a keyway A12. The outer wall of the can lid 2 has a key B21 protruding radially, and the area without key B21 has a keyway B22. Locking grooves 30 are recessed radially on key A11 and key B21, and an axial locking member 3 matching the shape of the locking groove 30 is provided. Thus, when the can lid 2 and the can body 1 are closed, key B21 is matched and locked in the keyway A12, and key A11 is matched and locked in the keyway B22. The axial locking member 3 is matched and locked in the locking groove 30 to achieve axial locking between the can lid 2 and the can body 1, and an effective seal can be formed.

[0031] This connection method between the can body 1 and the can lid 2 ensures a stable fit between them, effectively preventing the can lid 2 from falling off. It also provides good sealing, effectively preventing the PCM from expanding and overflowing after being heated. Furthermore, it allows for a tight fit without damaging the coating, thereby greatly reducing direct contact between the PCM and HTF.

[0032] As an improvement, such as Figures 3-4 As shown, the key B21 includes a first part 201 connected to the outer wall of the can lid 2 and a second part 202 extending from the first part 201 along the axial direction of the can lid 2, wherein the second part 202 is fitted into the keyway A12 and the locking groove 30 is formed on the second part 202.

[0033] As an improvement, the can lid 2 includes a lid body 24 with an outer diameter greater than the inner diameter of the can body 1 and an inner plug 25 connected to the bottom of the lid body 24 with an outer diameter not greater than the inner diameter of the can body 1, the inner plug 25 being fitted into the can body 1.

[0034] As an improvement, the composite graphite phase change thermal storage unit uses graphite material and is coated with a ceramic coating on both the inner and outer surfaces.

[0035] In this embodiment, the heat storage unit is made entirely of graphite material and coated with a dense ceramic coating on both the inner and outer surfaces. By using graphite and a dense coating, the heat storage unit can be adapted to harsher environments, including the corrosiveness of PCM, the corrosiveness of HTF, and a higher heat storage temperature range, thereby possessing high temperature resistance, corrosion resistance, and impermeability.

[0036] As a preferred embodiment, the dense coating can also be made of other organic materials such as resin coatings, or inorganic materials such as tantalum carbide coatings or silicon carbide coatings.

[0037] In a preferred embodiment, the tank body 1 has a height of 100~500mm, a diameter of 20~200mm, and a wall thickness of 2~15mm; the tank cover 2 has a thickness of 10~50mm; the ceramic coating has a thickness of 10~100μm; and the heat storage unit is applicable to temperatures ranging from -100 to 1500℃.

[0038] Example 2 The components in this embodiment that are the same as or corresponding to those in the above embodiments are referred to by the same reference numerals as those in the above embodiments. For the sake of simplicity, only the differences between this embodiment and the above embodiments are described below. The difference between this embodiment and the above embodiments is that: like Figure 1As shown, as an improvement, at least two keys A11 are distributed at intervals along the circumference of the can body 1, and keyways A12 are formed between two adjacent keys A11; at least two keys B21 are distributed at intervals along the circumference of the can cover 2, and keyways B22 are formed between two adjacent can covers 2.

[0039] As an improvement, two of each of the keys A11 and B21 are provided.

[0040] As an improvement, the key A11 is configured to be adapted to the size of the keyway B22, and the key B21 is configured to be adapted to the size of the keyway A12.

[0041] As an improvement, the composite graphite phase change heat storage unit is configured as a cylindrical tank structure, and the axial locking member 3, key A11, keyway A12, key B21 and keyway B22 are matched and configured as an arc-shaped structure.

[0042] In a preferred embodiment, the arc angle of key A11 is 60~135°, the arc angle of key B21 is 45~120°, and the arc angle of keyway is 50~150°.

[0043] Example 3 The components in this embodiment that are the same as or corresponding to those in the above embodiments are referred to by the same reference numerals as those in the above embodiments. For the sake of simplicity, only the differences between this embodiment and the above embodiments are described below. The difference between this embodiment and the above embodiments is that: like Figure 1 As shown, as an improvement, the composite graphite phase change heat storage unit is configured as a rectangular tank or an elliptical tank structure, and the axial locking member 3, key A11, keyway A12, key B21 and keyway B22 are matched and configured as straight or arc-shaped structures.

[0044] It should be noted that the heat storage unit in this application is not limited to a circular tank. It can also be made into a rectangular tank, an elliptical tank, or other covered tanks. Correspondingly, key A11, keyway A12, key B21, and keyway B22 can be made into rectangular or other shapes. As long as they can achieve the function of axial locking, they are all within the protection scope of this utility model.

[0045] Example 4 A type of tank-type phase change heat storage heat exchanger, such as Figures 5-6 As shown, it includes a heat exchanger housing 4; it also includes a composite graphite phase change heat storage unit as described in any of the above embodiments, which has a built-in PCM. At least one layer of baffles 5 is distributed axially inside the heat exchanger housing 4. Mounting holes 51 are distributed on the baffles 5. The composite graphite phase change heat storage unit is mounted on the mounting holes 51 by key A11 and key B21.

[0046] In this embodiment, the heat storage unit is installed and fixed in the heat exchanger by suspension. The arrangement is flexible and varied. By adjusting the suspension angle and the arrangement density, the flow field of the HTF can be adjusted, turbulence can be formed, and the heat exchange efficiency can be improved.

[0047] As an improvement, such as Figure 7 As shown, the diameter of the mounting hole 51 is greater than the outer diameter of the can body 1 and smaller than the outer diameters of the keys A11 and B21, so that the can body 1 extends into the mounting hole 51 until the keys A11 and B21 are limited to the outside of the mounting hole 51.

[0048] As an improvement, such as Figure 6 As shown, the baffle plate 5 is provided with a cut portion 50. The baffle plate 5 is provided with at least two layers and the cut portions 50 are staggered layer by layer to guide the HTF fluid in the heat exchanger shell 4 to flow and exchange heat in a spiral manner layer by layer.

[0049] As a preferred implementation method, such as Figure 8 As shown, the cut portions 50 of the two adjacent layers of baffles 5 are arranged at 180° relative to each other to guide the HTF fluid in the heat exchanger shell 4 to flow and exchange heat layer by layer in an S-shape.

[0050] In this embodiment, the baffles 5 on two adjacent layers are staggered with cut sections 50 to guide the HTF fluid in the heat exchanger shell 4 to flow and exchange heat layer by layer along the guide path of the cut sections 50, thereby increasing the heat exchange time and improving the heat exchange efficiency.

[0051] As an improvement, such as Figure 6 , Figure 9 As shown, it also includes a positioning rod assembly 6, which has multiple sets distributed along the circumferential edge of the baffle 5. It positions and calibrates the installation angle of each layer of the baffle 5 so that the cut-out portion 50 is staggered layer by layer according to the set angle.

[0052] In this embodiment, the installation angle of the baffle plate 5 is positioned and calibrated by setting a positioning rod structure so that the cut parts of each layer of baffle plate 5 are staggered layer by layer according to the set angle, such as 60°, 90°, 180° etc.

[0053] As an improvement, such as Figure 9 As shown, the positioning rod assembly 6 includes an inner rod 61 and a sleeve rod 62. The inner rod 62 is disposed through the circumferential edge of the baffle plate 5 to connect multiple baffle plates 5 in series. The sleeve rod 62 is sleeved on the inner rod 61 between two adjacent baffle plates 5. The two axial ends of the sleeve rod 62 abut against two adjacent baffle plates 5 respectively to fix and limit the axial distance between the two baffle plates 5.

[0054] As an improvement, the positioning rod assembly 6 is provided in four sets along the circumferential edge of the baffle plate 5.

[0055] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A composite graphite phase change heat storage unit, characterized in that, The container includes a tank body (1), a lid (2) that matches and fits the tank body (1), and an axial locking member (3). The outer wall of the tank body (1) at the opening is radially provided with a key A (11), and the circumference of the tank body (1) includes an area with the key A (11) and an area without the key A (11), wherein the area without the key A (11) is provided with a keyway A (12). The outer wall of the lid (2) is radially provided with a key B (21), and the circumference of the lid... (2) includes a region where key B (21) is set and a region where key B (21) is not set. The region where key B (21) is not set is provided with key groove B (22). Locking groove (30) is recessed radially on key A (11) and key B (21). After key B (21) is matched and locked in key groove A (12) and key A (11) is matched and locked in key groove B (22), the axial locking member (3) is matched and locked in locking groove (30).

2. The composite graphite phase change heat storage unit according to claim 1, characterized in that, The key A (11) is distributed at least two times along the circumferential direction of the can body (1), and a keyway A (12) is formed between two adjacent keys A (11); the key B (21) is distributed at least two times along the circumferential direction of the can cover (2), and a keyway B (22) is formed between two adjacent can covers (2).

3. The composite graphite phase change heat storage unit according to claim 2, characterized in that, This composite graphite phase change thermal storage unit uses graphite material and is coated with a ceramic coating on its inner and outer surfaces.

4. The composite graphite phase change heat storage unit according to claim 1, characterized in that, The composite graphite phase change heat storage unit is configured as a cylindrical tank structure, and the axial locking member (3), key A (11), keyway A (12), key B (21) and keyway B (22) are matched and configured as an arc-shaped structure.

5. The composite graphite phase change heat storage unit according to claim 1, characterized in that, The composite graphite phase change heat storage unit is configured as a rectangular tank or an elliptical tank structure, and the axial locking member (3), key A (11), keyway A (12), key B (21) and keyway B (22) are matched and configured as straight or arc-shaped structures.

6. The composite graphite phase change heat storage unit according to claim 1, characterized in that, The key B (21) includes a first part (201) connected to the outer wall of the can lid (2) and a second part (202) extending from the first part (201) along the axial direction of the can lid (2), wherein the second part (202) is fitted into the keyway A (12) and the locking groove (30) is formed on the second part (202).

7. The composite graphite phase change heat storage unit according to claim 1, characterized in that, The can lid (2) includes a lid body (24) with an outer diameter greater than the inner diameter of the can body (1) and an inner plug (25) connected to the bottom of the lid body (24) with an outer diameter not greater than the inner diameter of the can body (1). The inner plug (25) is fitted into the can body (1).

8. A tank-type phase change heat storage heat exchanger, comprising a heat exchanger shell (4); characterized in that, It also includes a composite graphite phase change heat storage unit as described in any one of claims 1-7, wherein at least one layer of baffles (5) is distributed axially inside the heat exchanger shell (4), and mounting holes (51) are distributed on the baffles (5), and the composite graphite phase change heat storage unit is mounted on the mounting holes (51) by means of key A (11) and key B (21).

9. The tank-type phase change heat storage heat exchanger according to claim 8, characterized in that, The baffle plate (5) is provided with a cut portion (50), and the baffle plate (5) is provided with at least two layers and the cut portions (50) are staggered layer by layer to guide the HTF fluid in the heat exchanger shell (4) to flow and exchange heat in a spiral manner layer by layer.

10. The tank-type phase change heat storage heat exchanger according to claim 9, characterized in that, The cut portions (50) of the two adjacent layers of baffles (5) are arranged at 180° opposite each other to guide the HTF fluid in the heat exchanger shell (4) to flow and exchange heat layer by layer in an S-shape; It also includes a positioning rod assembly (6), which has multiple sets distributed along the circumferential edge of the baffle (5) to position and calibrate the installation angle of each layer of the baffle (5) so that the cut part (50) is staggered layer by layer according to the set angle.

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