Thermochemical heat storage device
By adopting a layered box structure and thermally conductive fin design in the thermochemical energy storage device, the problem of low heat transfer efficiency of the heat storage material is solved, and more efficient heat conduction and reaction conversion are achieved.
Patent Information
- Application Number
- CN202520311519.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-02-26
AI Technical Summary
In existing thermochemical energy storage devices, the large-area, thick stacking of heat storage materials leads to low heat and mass transfer efficiency, affecting the heat release/storage effect.
The box structure is arranged in layers with intervals. The box is equipped with heat-conducting fins distributed along the thickness direction. Combined with the support components and heating unit, the heat-conducting fins are used to accelerate heat conduction and improve heat transfer efficiency.
It accelerates the heat release/storage process of thermochemical energy storage devices, and improves reaction conversion rate and efficiency.
Smart Images
Figure CN223925519U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of thermal energy storage equipment technology, and specifically provides a thermochemical thermal energy storage device. Background Technology
[0002] The continuous consumption of fossil fuels has led to a series of environmental problems that have impacted human activities, making the development of renewable energy and corresponding energy storage systems extremely necessary. Thermal energy storage, a type of large-scale energy storage, is an effective means of achieving efficient utilization of renewable energy. Thermal energy storage methods include sensible heat storage, latent heat storage, and thermochemical storage. Among these, thermochemical storage boasts advantages such as high energy density, long-term energy storage, and long-distance transportation, making it highly compatible with fields such as solar energy storage and industrial high-temperature heat storage. It is also currently the thermal energy storage method with the highest energy density.
[0003] Common thermochemical energy storage devices are mostly gas-solid reaction thermal storage systems. Since the thermal storage materials are mostly powder structures and are mainly stacked in a large area and thickness in a fixed bed, in practical applications, the large area and thickness of the thermal storage materials can easily affect the efficiency of heat and mass transfer, reducing the heat release / storage effect of the thermochemical energy storage device. Utility Model Content
[0004] The purpose of this invention is to solve the problem of poor heat transfer efficiency within the heat storage material in existing thermochemical energy storage devices.
[0005] The objective of this utility model is achieved through the following technical solution:
[0006] This utility model provides a thermochemical heat storage device, which includes: a shell with an air inlet and an air extraction port communicating with the inner cavity of the shell; a support member disposed within the cavity of the shell; a heat storage unit located within the cavity of the shell, the heat storage unit including multiple boxes and heat storage material filled in each box, the multiple boxes being arranged in layers at intervals on the support member; and a heating unit for providing heat to the heat storage unit; the heat storage unit further includes heat-conducting fins disposed within the boxes, the heat-conducting fins being distributed along the thickness direction of the boxes.
[0007] Preferably, the heat-conducting fins are provided with through holes.
[0008] Preferably, the heat-conducting fins are arranged in at least one of the following structures: grid-shaped structure, honeycomb structure, wave-shaped structure, cross-shaped structure, and spoke-shaped structure.
[0009] Preferably, the filling volume of the heat storage material does not exceed 85% of the internal volume of the box.
[0010] Preferably, the supporting member includes multiple sets of heat exchange coils, which are fixed in layers on the inner wall of the shell. Each set of heat exchange coils is supported at the bottom of each box, and the heat exchange coils are spaced apart from the top of the adjacent box to form a reserved space.
[0011] Preferably, the reserved space is spaced at least 2 cm apart in the layering direction.
[0012] Preferably, the housing is further provided with a split pipe that communicates with the air intake interface, and the split pipe is provided with a split port, which is opposite to the reserved space.
[0013] Preferably, the heat exchange coil adopts a flat tube structure.
[0014] Preferably, the box body is made of 100-300 mesh metal mesh.
[0015] Preferably, the housing includes a cover and a one-way open cylinder, the cover being sealed to the cylinder, the air inlet and the air extraction port being located on the cylinder, and the cylinder also having a drain port located at the horizontal bottom end of the cylinder.
[0016] Preferably, the heating unit includes an electromagnetic inductor or a resistance coil disposed on the outer side wall of the housing, and heat sinks are disposed on the inner side wall of the housing.
[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0018] This invention provides a thermochemical heat storage device, comprising a shell, a supporting member, a heat storage unit, and a heating unit. The shell has an air inlet and an air outlet communicating with the inner cavity of the shell. The supporting member is disposed within the cavity of the shell, and the heat storage unit is located within the cavity of the shell. The heat storage unit includes multiple boxes and heat storage material filling each box. The multiple boxes are arranged in layers on the supporting member at intervals. The heating unit provides heat to the heat storage unit. The heat storage unit also includes heat-conducting fins disposed within the boxes, distributed along the thickness direction of the boxes. This arrangement allows the heat-conducting fins to be deeply embedded in the heat storage material. When the heat storage unit releases / stores heat, the heat can be rapidly conducted from the inside to the outside or from the outside to the inside of the heat storage material via the heat-conducting fins, accelerating the heat release / storage process and improving the efficiency and reaction conversion rate of the thermochemical energy storage device. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the overall structure of the thermochemical heat storage device of this utility model;
[0020] Figure 2This is an overall axial sectional view of the thermochemical heat storage device of this utility model;
[0021] Figure 3 This is a schematic diagram of the supporting components of the thermochemical heat storage device of this utility model;
[0022] Figure 4 This is a schematic diagram of the structure of a preferred heat storage unit in the thermochemical heat storage device of this utility model;
[0023] Figure 5 This is a schematic diagram of another preferred heat storage unit in the thermochemical heat storage device of this utility model;
[0024] Figure 6 This is a schematic diagram of the arrangement of the honeycomb fin structure in the heat storage unit of this utility model;
[0025] Figure 7 This is a schematic diagram of the arrangement of the grid-shaped fin structure in the heat storage unit of this utility model;
[0026] Figure 8 This is a schematic diagram of the arrangement of the corrugated fin structure in the heat storage unit of this utility model;
[0027] Figure 9 This is a schematic diagram of the arrangement of the spoke-shaped fin structure in the heat storage unit of this utility model;
[0028] Figure 10 This is a comparison diagram of the internal pressure drop of the thermochemical heat storage device of this utility model.
[0029] Reference numerals: 1-Cylinder; 11-Air inlet; 12-Air extraction; 13-Heat exchange medium inlet; 14-Heat exchange medium outlet; 15-Drainage port; 16-Reserved space; 17-Heat fins; 2-Cap; 21-Bolt; 3-Heating unit; 4-Heat storage unit; 41-Box; 42a-Honeycomb fin structure; 42b-Grid fin structure; 42c-Corrugated fin structure; 42d-Spoke fin structure; 43-Heat storage material; 5-Supporting component; 6-Diverter pipe; 61-Diverter port. Detailed Implementation
[0030] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.
[0031] It should be noted that in the description of this utility model, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on 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.
[0032] like Figure 1 and Figure 2 As shown, this utility model provides a thermochemical heat storage device, which includes a shell, a supporting member 5, a heat storage unit 4, and a heating unit 3. The supporting member 5 and the heat storage unit 4 are both located within the cavity of the shell. The shell is provided with an air inlet 11 and an air extraction 12 communicating with the inner cavity of the shell. The heat storage unit 4 includes multiple boxes 41 and heat storage material 43 filled in each box 41. The multiple boxes 41 are arranged in layers on the supporting member 5 at intervals. The heating unit 3 provides heat to the heat storage unit 4. The heat storage unit 4 also includes heat-conducting fins disposed within the boxes 41, distributed along the thickness direction of the boxes 41. With this arrangement, the heat-conducting fins can be deeply embedded in the heat storage material 43. When the heat storage unit 4 releases / stores heat, the heat can be rapidly conducted from the inside to the outside or from the outside to the inside of the heat storage material 43 through the heat-conducting fins, accelerating the heat release / storage process and improving the efficiency of heat release / storage within the thermochemical energy storage device.
[0033] Specifically, such as Figure 1 and Figure 2 As shown, in this embodiment of the invention, the shell includes a cover 2 and a one-way open cylindrical body 1, which are connected by bolts 21. A graphite gasket is used to seal the cover 2 and the cylindrical body 1 to ensure the shell's airtightness and prevent external contamination. Both the cover 2 and the cylindrical body 1 are made of 301S heat-resistant steel. The length of the cylindrical body 1 is 500mm, and its diameter is 400mm. The air inlet 11 and the air extraction 12 are both located on the right side of the cylindrical body 1. Preferably, in this embodiment, the cylindrical body 1 is placed horizontally.
[0034] like Figure 2 and Figure 3 As shown, in this embodiment of the utility model, the support member 5 includes five sets of heat exchange coils. The five sets of heat exchange coils are fixed on the inner wall of the shell in layers. Each set of heat exchange coils is supported at the bottom of each box 41. The heat exchange coils and the top of the adjacent box 41 are spaced apart to form a reserved space 16. The reserved space 16 is at least 2cm apart in the layering direction.
[0035] For example, five sets of heat exchange coils are arranged horizontally in layers, with a 10cm interval between each layer. The thickness of the housing 41 is 6cm, so the reserved space 16 has a 4cm spacing in the layering direction. The heat exchange coils are made of stainless steel with a flat tubular structure, 5mm wide, ensuring good heat transfer between the coils and the housing 41. The heat exchange coils can be fixed to the inner wall of the housing 1 by welding, or by using a clip structure on the inner wall of the housing 1. The five sets of heat exchange coils can be connected in series or in parallel. Preferably, in this embodiment, the heat exchange coils are horizontally fixed to the inner wall of the housing 1 by welding to enhance heat transfer between the housing 1 and the heat exchange coils, with the five sets of heat exchange coils connected in series.
[0036] It should be noted that, based on actual applications, the thickness of the box 41 is designed to range from 1cm to 10cm. Correspondingly, the spacing between each heat exchange coil is also adjusted according to the thickness of the box, so that the reserved space 16 has a spacing of at least 2cm in the layering direction.
[0037] Continue to refer to, for example Figure 2 and Figure 3 In this embodiment of the invention, the shell is further provided with a heat exchange interface, and the heat exchange coil is connected to the heat exchange interface. Specifically, the heat exchange interface includes a heat exchange medium inlet 13 and a heat exchange medium outlet 14 disposed in the shell 1, and both ends of each set of heat exchange coils are connected to the heat exchange medium inlet 13 and the heat exchange medium outlet 14, respectively. In addition, the shell 1 is also provided with a drain port 15 located at the horizontal bottom end of the shell 1. The pipe diameter of the five ports, namely the heat exchange medium inlet 13, the heat exchange medium outlet 14, the drain port 15, the air inlet port 11, and the air extraction port 12, is 15mm. It should be noted that both the air inlet port 11 and the air extraction port 12 are provided with filters to filter particulate media.
[0038] It should be noted that the heat exchange medium enters through the heat exchange medium inlet 13 and flows sequentially from the bottom up through each heat exchange coil in the layer, and then flows out through the heat exchange medium outlet 14 to carry a large amount of heat energy.
[0039] like Figure 2 As shown, in this embodiment of the present invention, a diversion pipe 6 communicating with the air inlet is also provided inside the shell. The diversion pipe 6 is provided with a diversion port 61, which is opposite to the reserved space 16. The diversion pipe 6 is vertically fixed inside the cylinder 1, and the diversion pipe 6 is provided with multiple diversion ports 61, each of which corresponds to a reserved space 16 in a different layer.
[0040] like Figure 1 and Figure 2As shown, the heating unit 3 of this invention includes an electromagnetic induction heater or a resistance coil. In this embodiment, the heating unit 3 uses an electromagnetic induction coil wound around the outer wall of the cylinder 1, which can quickly heat the cylinder 1. The inner wall of the cylinder 1 is provided with heat dissipation fins 17, which can dissipate the heat after the cylinder 1 is heated, accelerating the heating efficiency inside the cylinder 1. During the heat release process, the heating unit 3 is used to preheat the cylinder 1 to provide the suitable temperature required for the heat storage unit 4 to perform the heat release reaction. During the heat storage process, the heating unit 3 is the heat source for the heat storage unit 4 to store heat.
[0041] It should be noted that the outer surface of the shell of the thermochemical heat storage device is provided with an insulation layer (not shown in the figure). Specifically, the insulation layer is insulation cotton, which covers the cylinder 1 and the electromagnetic induction heater on the cylinder to reduce the loss of internal heat from the thermochemical heat storage device.
[0042] Installation of thermal storage unit 4: The box 41 of thermal storage unit 4 is made of 100-300 mesh metal mesh, and the thermal storage material 43 filled inside the box 41 is at least one of CaO / Ca(OH)2, MgO / Mg(OH)2, and CaO / CaCO3.
[0043] The metal mesh of the housing 41 is made using a sintering process, which facilitates uniform permeation of the reaction gas through the metal mesh to achieve uniform mass transfer. This means that the reaction medium can enter through any wall surface of the housing 41 or escape from the heat storage material 43 through any wall surface of the housing 41, and the sintered metal mesh prevents leakage from the heat storage material 43. The metal mesh, heat-conducting fins, and heat sink 17 are all made of stainless steel.
[0044] For example, powdered CaO / Ca(OH)2 material with a median particle size of 100 micrometers is filled into a box 41 made of 200-mesh metal mesh. The filling volume of the heat storage material 43 does not exceed 85% of the volume of the box 41 to ensure that at least 15% expansion space is reserved inside the box 41. This avoids excessive expansion during the hydration reaction of CaO with saturated water vapor, which could lead to overflow or compression. This ensures that the heat release process of the heat storage unit 4 proceeds safely and stably, while maximizing the heat storage capacity.
[0045] The casing 41, filled with thermal storage material 43, is placed stably in layers on the heat exchange coil, ensuring complete contact between the bottom of the casing 41 and the heat exchange coil. The open end of the casing 1 is then fitted with a cap 2 and sealed. A vacuum pump is connected to the extraction port 12 to extract air from the casing, creating a vacuum environment to prevent air from reacting with the thermal storage material 43 and ensuring the thermal storage material 43 remains stable, thus completing the preparation of the thermal storage unit 4. It should be noted that the horizontally detachable placement and installation of the casing 41 improves the flexibility of assembling and replacing the thermal storage material 43, enabling modular management of the thermal storage material 43.
[0046] It should be noted that, depending on the actual application, those skilled in the art may select either a lidded or lidless box for the 41. For example... Figure 4 and Figure 5 As shown, in this embodiment of the present invention, the box 41 is without a lid. In the case with a lid, screws are used to fix the lid to the box 1.
[0047] like Figure 4 As shown, in a preferred embodiment of the thermochemical heat storage device of this utility model, the box 41 has a rectangular cubic structure. Figure 7 , Figure 6 and Figure 8 As shown, the heat-conducting fins inside the box 41 can be arranged in a grid-like structure, a honeycomb structure, or a corrugated structure. That is, the fins are arranged in a grid-like structure 42b with alternating horizontal and vertical spacing, the fins are arranged in a hexagonal structure to form a honeycomb fin structure 42a, and the fins are alternately bent and arranged in parallel to form a corrugated fin structure 42c.
[0048] like Figure 5 As shown, in another preferred embodiment of the thermochemical heat storage device of this utility model, the box 41 has a cylindrical / disc-shaped structure. Figure 9 As shown, the heat-conducting fins inside the box 41 are arranged in a spoke-shaped structure. That is, the fins are distributed circumferentially with the center of the box 41 as the center to form a spoke-shaped fin structure 42d.
[0049] The aforementioned heat-conducting fins can be welded and fixed to the bottom of the box 41, or they can be welded and fixed to the side wall of the box 41, with the heat-conducting fins extending beyond the box 41 in the thickness direction. It should be noted that in practical applications, those skilled in the art can also modify the fin arrangement structure and installation method according to the heat storage requirements, as long as it is ensured that the heat-conducting fins can extend into the interior of the heat storage material 43 to maximize the heat transfer effect of the heat-conducting fins.
[0050] like Figures 6 to 9 As shown, the heat-conducting fins are provided with multiple through holes, each with a diameter of 0.5-2 cm, preferably 1.5 cm. During the CaO / Ca(OH)2 exothermic / heat storage process, water vapor in the heat storage material 43 can diffuse to the adjacent area through the through holes to accelerate the exothermic / heat storage reaction and improve the exothermic / heat storage efficiency of the heat storage unit 4.
[0051] The working principle of this thermochemical heat storage device is as follows:
[0052] Heat release principle: Taking CaO / Ca(OH)2 as the heat storage material 43 as an example, when the inlet port 11 is filled with the reaction gas (saturated water vapor), the reaction gas is sprayed from the branch port 61 of the branch pipe 6 into the reserved space 16 of each layer and quickly and evenly diffuses and flows to fill the entire chamber, so that the water vapor can react with the heat storage material 43 of each layer to release heat. At the same time, under pressure, the reaction gas flows through the box 41 and contacts the heat storage material 43 and diffuses into the interior of the heat storage material 43 to react fully and release a large amount of heat. The heat is quickly conducted from the interior of the heat storage material 43 to the box 41 through the heat conduction fins and from the bottom of the box 41 to the heat exchange coil. At the same time, the heat exchange medium (air / heat transfer oil) flows into the heat exchange coil of each layer from the heat exchange medium inlet 13. The heat exchange medium in the flow channel will transfer the heat to the heat exchange coil and the heat will flow out through the heat exchange medium outlet 14 to meet the external heat demand.
[0053] Furthermore, it should be noted that the thermochemical heat storage device of this utility model embodiment is also equipped with a temperature measuring probe (not shown in the figure) installed on the cylinder 1 or the sealing plate to monitor the temperature change inside the cylinder 1, thereby controlling the flow rate of the heat exchange medium and the reaction medium to achieve controllability of the heat release temperature.
[0054] Heat storage process: Heating unit 3 uses an electromagnetic induction coil to heat the shell. The heat is transferred to the heat storage unit 4 through the heat exchange coil to facilitate the heat storage reaction of the heat storage material 43. Specifically, part of the heat is used to quickly preheat the inner cavity of the shell via the heat sink 17, and another part of the heat is conducted to the bottom of the box 41 via the heat exchange coil acting as heat-conducting fins. Then, it is transferred to the interior of the heat storage material 43 through the heat-conducting fins inside the box 41, causing the Ca(OH)2 powder to absorb heat and undergo a dehydration reaction to produce water vapor. The water vapor flows outward through the reserved space 16 through the box 41. The water vapor can be directly discharged through the evacuation port 12, or after the dehydration reaction is completed, the shell is cooled, causing the water vapor to condense into water and collect at the bottom of the cylinder 1, and then discharged all at once through the drain port 15. Finally, the shell is evacuated to a vacuum state to ensure the chemical stability of the heat storage material 43.
[0055] like Figure 10 As shown, the thermal storage material 43 in this embodiment of the present invention uses a Ca(OH)2 / CaO material system for thermal storage pressure comparison testing. Specifically, the gas pressure of the reaction medium was measured when the thermal storage unit 4 was arranged with layered boxes 41 and when it was not layered. The comparison shows that the layered structure of the thermal storage unit 4 in this embodiment of the present invention can significantly reduce the gas pressure of the reaction medium, thereby improving the safety of the thermochemical thermal storage device and increasing the thermal storage efficiency.
[0056] The above are merely embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model shall be included within the scope of the claims of this utility model pending approval.
Claims
1. A thermo-chemical heat storage device, characterized in that, The application relates to a heat storage device. The heat storage device comprises a shell, a support member, a heat storage unit and a heating unit. The shell is provided with an air inlet interface (11) and an air outlet interface (12) which are communicated with a cavity in the shell. The support member (5) is arranged in the cavity of the shell. The heat storage unit (4) is arranged in the cavity of the shell and comprises a plurality of box bodies (41) and heat storage materials (43) filled in each box body (41). The plurality of box bodies (41) are arranged in layers on the support member (5).
2. The thermo-chemical heat storage device of claim 1, wherein, The heat storage unit (4) further comprises heat-conducting fins arranged in the box bodies (41).
3. The thermo-chemical heat storage device of claim 1, wherein, The heat-conducting fins are provided with through holes.
4. The thermal chemical storage device of claim 1, wherein, The heat-conducting fins are arranged in at least one of a cross-shaped structure, a honeycomb-shaped structure, a corrugated-shaped structure and a spoke-shaped structure.
5. The thermo-chemical heat storage device of claim 4, wherein, The support member (5) comprises a plurality of groups of heat exchange coils.
6. The thermo-chemical heat storage device of claim 4, wherein, Each group of heat exchange coils is supported at the bottom of each box body (41).
7. The thermo-chemical heat storage device of claim 1, wherein, The heat exchange coils and the top of the box body (41) in the adjacent layer are spaced to form a reserved space (16).
8. The thermo-chemical heat storage device of claim 1, wherein, The spacing distance of the reserved space (16) in the layer direction is not less than 2 cm.
9. The thermal chemical storage device of claim 1, wherein, The shell is further provided with a shunt pipe (6) communicated with the air inlet interface (11).
10. The thermo-chemical heat storage device of claim 1, wherein, The shunt pipe (6) is provided with a shunt port (61) opposite to the reserved space (16). The filling volume of the heat storage material (43) is not more than 85% of the content volume of the box body. The box body (41) is made of a metal mesh with a mesh size of 100-300. The shell comprises a cover (2) and a one-way open cylinder (1). The cover (2) is sealingly connected with the cylinder (1). The air inlet interface (11) and the air outlet interface (12) are arranged on the cylinder (1). The cylinder (1) is further provided with a drainage interface (15) located at the horizontal bottom end of the cylinder (1). The heating unit (3) comprises an electromagnetic inductor or a resistance coil arranged on the outer side wall of the shell. The inner side wall of the shell is provided with a heat sink (17).