High-thermal-conductivity composite phase change filling heat storage tank applied to solar heat supply system
By using high thermal conductivity composite phase change materials and special heat storage tank structure design in the solar heating system, the problem of poor thermal conductivity of heat storage materials is solved, and efficient and compact heat energy storage and release is achieved.
Patent Information
- Application Number
- CN202422233229.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-12
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-09-12
AI Technical Summary
In existing solar heating systems, the thermal conductivity of heat storage materials is poor, resulting in low heat storage density and large system volume, which makes it difficult to meet the needs of compact design and efficient thermal energy utilization.
The high thermal conductivity composite phase change material and special heat storage tank structure design are adopted, including double-layer spirally wound pipes and support frames, combined with suitable high thermal conductivity adsorption materials and phase change materials, to optimize the internal structure of the heat storage tank and improve heat conduction efficiency and heat storage density.
The heat exchange rate and heat storage efficiency of the heat storage tank are significantly improved, the overall volume of the system is reduced, and the demand for efficient thermal energy utilization is met.
Smart Images
Figure CN223345994U_ABST
Abstract
Description
Technical Field
[0001] What field does this utility model belong to? Specifically, it relates to a high thermal conductivity composite phase change filled heat storage tank used in a solar heating system. Background Art
[0002] With the continuous growth of energy demand and increasing awareness of environmental protection, solar energy, as a clean, renewable energy source, is gaining increasing attention and application. Solar heating systems utilize solar energy as their primary energy source, converting it into thermal energy through collectors and storing it for release when needed. In existing solar heating systems, common heat storage methods rely primarily on sensible heat storage materials, such as water or sand and gravel. These materials suffer from low heat storage density and large system size, limiting their compact design and efficient thermal energy utilization.
[0003] Phase change materials (PCMs) are increasingly being used in thermal energy storage systems due to their high heat storage density and constant-temperature heat release. PCMs undergo phase transitions (such as solid-to-liquid transitions) when absorbing or releasing heat, allowing them to store and release large amounts of thermal energy within a relatively small temperature range, significantly improving the performance of thermal energy storage systems. However, PCMs inherently have poor thermal conductivity, limiting their efficiency in practical applications.
[0004] Current technical solutions improve thermal conductivity by combining highly thermally conductive adsorbent materials with phase change materials to form highly thermally conductive composite phase change materials (CPCMs). Furthermore, to ensure uniform and efficient heat transfer during storage and release, the design of the heat storage tank must be optimized. However, existing technologies still face numerous technical challenges and practical application obstacles in terms of the selection of highly thermally conductive composite phase change materials, the compounding process, and the internal structural design of the heat storage tank. Utility Model Content
[0005] The purpose of this utility model is to provide a high-thermal-conductivity composite phase-change filler heat storage tank for use in solar heating systems. By combining a highly suitable high-thermal-conductivity adsorbent material with a phase-change material and employing a unique internal tank structure, this tank significantly improves heat storage efficiency and overall system performance, addressing the poor thermal conductivity and low heat storage density inherent in existing technologies. This invention enables solar heating systems to operate more efficiently and stably, while also meeting growing energy demands and environmental protection requirements.
[0006] To achieve the above-mentioned purpose, the present invention provides a high thermal conductivity composite phase change filled heat storage tank for use in a solar heating system, comprising a tank body, a horizontal heat exchange top plate fixedly provided at the upper end of the interior of the tank body, a horizontal heat exchange bottom plate fixedly provided at the lower end of the interior of the tank body, a heat storage bin provided between the heat exchange top plate and the heat exchange bottom plate, and a plurality of heat exchange pipes provided in the heat storage bin;
[0007] The heat storage bin is filled with a high thermal conductivity composite phase change material;
[0008] The top end of the tank body is fixedly provided with a heat exchange medium inlet, and the bottom end of the tank body is fixedly provided with a heat exchange medium outlet;
[0009] A plurality of support frames are fixedly provided at the lower end of the side wall of the tank body.
[0010] Furthermore, there are two heat exchange medium inlets, which are relatively arranged at the top end of the tank body, and there are two heat exchange medium outlets, which are relatively arranged at the bottom end of the tank body.
[0011] Furthermore, a first heat medium buffer tank is provided between the upper end of the heat exchange top plate and the inner part of the tank body, and a second heat medium buffer tank is provided between the lower end of the heat exchange bottom plate and the inner part of the tank body.
[0012] Furthermore, the heat exchange medium inlet connects the first heat medium buffer tank with the outside of the tank body, and the heat exchange medium outlet connects the second heat medium buffer tank with the outside of the tank body.
[0013] Furthermore, the heat exchange pipe includes a plurality of inner ring bends and outer ring bends, and the inner ring bends and outer ring bends are staggered and equidistantly spirally wound from the inside to the outside, and the spiral directions of the inner ring bends and the outer ring bends are opposite.
[0014] Furthermore, the shell of the tank body consists of an outer wall, an insulation layer and an inner wall, and the insulation material used in the insulation layer is at least one of polyurethane foam, glass wool, aerogel felt, aluminum silicate wool and rock wool.
[0015] Furthermore, there are three support frames in total, the top ends of the support frames are fixedly arranged at equal distances on the side walls of the bottom of the tank body, the bottom ends of the support frames are fixedly connected to the ground, and the three support frames are arranged at equal distances in an equilateral triangle.
[0016] The utility model provides a high thermal conductivity composite phase change filled heat storage tank for use in a solar heating system. While ensuring structural stability, it reduces the overall volume of the system and effectively improves space utilization. The use of high thermal conductivity composite phase change materials and double-layer spirally wound pipes greatly improves the heat exchange rate of the heat storage tank, enables rapid and uniform transfer of heat energy, improves the efficiency of heat storage and release, and meets the demand for efficient heat energy utilization.
[0017] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic structural diagram of the utility model.
[0019] Figure 2 It is a top view schematic diagram of the top plate of the heat exchange pipe of the present invention.
[0020] Figure 3 It is a schematic diagram of the tank structure of the utility model.
[0021] Explanation of the accompanying drawings: 1. Tank body; 101. Outer wall; 102. Insulation layer; 103. Inner wall; 2. Heat exchange top plate; 3. Heat exchange bottom plate; 4. Heat storage bin; 5. Heat exchange pipe; 501. Inner bend; 502. Outer bend; 6. High thermal conductivity composite phase change material; 7. Heat exchange medium inlet; 8. Heat exchange medium outlet; 9. Support frame; 10. First heat medium buffer bin; 11. Second heat medium buffer bin. DETAILED DESCRIPTION
[0022] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose, the specific implementation methods, structural features and effects of the present invention are described in detail below with reference to the accompanying drawings and embodiments.
[0023] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0024] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "aligned", "overlap", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0025] 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 quantity of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; and in the description of this utility model, unless otherwise specified, "plurality" means two or more.
[0026] Example 1
[0027] This embodiment provides Figures 1 to 3The high thermal conductivity composite phase change filled heat storage tank used in the solar heating system shown in the figure includes a tank body 1, a horizontal heat exchange top plate 2 is fixedly provided at the upper end of the interior of the tank body 1, a horizontal heat exchange bottom plate 3 is fixedly provided at the lower end of the interior of the tank body 1, a heat storage bin 4 is provided between the heat exchange top plate 2 and the heat exchange bottom plate 3, and a plurality of heat exchange pipes 5 are provided in the heat storage bin 4. The material used for the tank body 1 is 304 stainless steel. While ensuring the overall stability of the heat storage tank structure, stainless steel has more superior anti-corrosion and wear-resistant properties. The interior of the tank body 1 includes, from top to bottom, a heat exchange top plate 2, a heat storage bin 4, and a heat exchange bottom plate 3. The heat storage bin 4 is a cylindrical cavity formed in the middle of the tank body 1 after the heat exchange top plate 2 and the heat exchange bottom plate 4 separate the tank body 1. A heat exchange pipe 5 is arranged inside the heat storage bin 4. The heat exchange medium exchanges heat in the heat exchange pipe 5. The heat exchange pipe 5 is made entirely of copper. The excellent thermal conductivity and corrosion resistance of copper greatly improve the heat exchange efficiency and significantly extend the life of the heat exchange pipe 5.
[0028] The interior of the heat storage bin 4 is also filled with a high thermal conductivity composite phase change material 6, which fills the gap between the heat exchange pipe 5 and the heat storage bin 4, ensuring that the heat exchange medium can better exchange heat with the heat stored in the high thermal conductivity composite phase change material 6 when flowing in the heat exchange pipe 5;
[0029] A heat exchange medium inlet 7 is fixedly provided at the top of the tank body 1, and a heat exchange medium inlet 7 is fixedly provided at the bottom of the tank body 1. The specific heat exchange medium passes through the heat exchange medium inlet 7;
[0030] A plurality of support frames 9 are fixedly provided at the lower end of the side wall of the tank body 1 , and the support frames 9 are used to support and fix the entire tank body 1 and increase its stability.
[0031] Further, such as Figure 1 As shown, two heat exchange medium inlets 7 are provided and are relatively arranged at the top of the tank body 1, and two heat exchange medium inlets 7 are also provided and are relatively arranged at the bottom of the tank body 1. The two heat exchange medium inlets 7 are relatively arranged at the top of the tank body 1. When in use, the heat exchange medium can be added together to improve the overall heat exchange efficiency of the heat storage tank. Similarly, two heat exchange medium inlets 7 are relatively arranged at the bottom of the tank body 1, so that the discharge of the heat exchange medium is more efficient, and the overall heat exchange medium pressure inside the heat storage tank is more stable, and the operation is smoother.
[0032] Furthermore, a first heat medium buffer tank 10 is provided between the upper end of the heat exchange top plate 2 and the interior of the tank body 1 , and a second heat medium buffer tank 11 is provided between the lower end of the heat exchange bottom plate 3 and the interior of the tank body 1 .
[0033] Furthermore, the heat exchange medium inlet 7 connects the first heat medium buffer tank 10 with the outside of the tank body 1 , and the heat exchange medium outlet 8 connects the second heat medium buffer tank 11 with the outside of the tank body 1 .
[0034] Specifically, the arrangement of the heat exchange top plate 2 forms an additional semi-elliptical cavity with the upper end of the tank body 1: a first heat medium buffer bin 10. When the heat exchange medium is injected, the heat exchange medium flows into the first heat medium buffer bin 10 from the heat exchange medium inlet 7, so that the heat exchange medium can flow into the heat exchange pipe 5 more evenly and uniformly; the heat exchange bottom plate 3 and the tank body 1 form a second heat medium buffer bin 11. When the heat exchange medium flows out of the heat exchange pipe 5, it will fill the second heat medium buffer bin 11 and then flow out of the tank body 1 through the heat exchange medium outlet 8. Ultimately, the balance of the liquid pressure in the heat storage tank is ensured, and the flow rate of the heat exchange medium is controlled not to be too fast, so that the heat exchange medium can more fully exchange heat in the heat storage tank.
[0035] The heat exchange medium inlet 7 and the heat exchange medium outlet 8 are both connected to the external pipes through flanges. The use of flanges can achieve better airtightness and higher connection strength, which can avoid the heat exchange medium from flowing out of the connection and causing waste of resources, and further ensure the overall internal pressure of the heat storage tank, making the heat exchange process more stable and smooth.
[0036] Further, such as Figure 2 As shown, the heat exchange pipe 5 includes a plurality of inner bends 501 and outer bends 502. The inner bends 501 and the outer bends 502 are staggered and equidistantly spirally wound from the inside to the outside. The spiral directions of the inner bends 501 and the outer bends 502 are opposite.
[0037] Eight heat exchange pipes 5 are arranged in the heat storage bin 4, including four outer ring bends 502 staggered and equidistantly wound in a clockwise spiral on the outer circle, and four inner ring bends 501 staggered and equidistantly wound in a clockwise spiral on the inner circle. The heat exchange inlet of the inner ring bend 501 is located at the quarter point of the inner circle of the heat exchange top plate 2, and the pipe mouth is welded to the heat exchange top plate 2. The four inner ring bends 501 form an inner ring heat exchange pipe layer, and the heat exchange inlet of the outer ring bend 502 is located at the quarter point of the outer circle of the heat exchange top plate 2. The four outer ring bends 502 form an outer ring heat exchange pipe layer. By arranging the heat exchange pipes 5 at the quarter points of the inner and outer circles, the overall force of the heat exchange pipes 5 can be made more uniform, the stress concentration of the heat exchange pipes 5 caused by thermal expansion and contraction or fluid pressure changes is reduced, and the overall structural stability of the system is improved. The inner and outer ring heat exchange pipe layers are respectively wound in a clockwise and counterclockwise spiral to reduce dead angles and invalid space, increase the path length of the fluid in the heat exchange pipe, and thus improve the compactness and efficiency of the equipment.
[0038] The double-layer spirally wound tube increases the contact area between the heat exchange medium and the high thermal conductivity composite phase change material 6 in the heat exchange pipe 5, greatly improving the heat exchange rate of the heat storage tank. The equidistant arrangement of the spirals allows the heat exchange medium to flow at a uniform speed in the heat exchange pipe 5, avoiding the acceleration that generates a large impact force on the heat exchange pipe 5, causing an impact on the entire heat storage tank, affecting the heat exchange efficiency and damaging the structure.
[0039] Furthermore, the shell of the tank body 1 is composed of an outer wall 101, an insulation layer 102 and an inner wall 103. The insulation material used in the insulation layer 102 includes at least one of polyurethane foam, glass wool, aerogel felt, aluminum silicate wool and rock wool. The insulation material is filled between the outer wall 101 and the inner wall 103 of the tank body 1 to form the insulation layer 102, which can further retain the temperature inside the tank body 1 so that it will not overflow and cause temperature loss.
[0040] Furthermore, there are three support frames 9, the top ends of the three support frames 9 are equidistantly fixed on the side walls of the bottom of the tank body 1, and the bottom ends of the support frames 9 are fixedly connected to the ground. The three support frames 9 are equidistantly arranged around the tank body 1 in an equilateral triangle. Since the heat exchange medium flows spirally in the tank body 1, the support frames 9 are arranged to fix the entire tank body 1 to the ground to stabilize the entire tank body 1 so that it will not shake due to force. The triangular arrangement allows the support frames 9 to bring the most stable supporting force and can also offset the lateral impact force of the heat exchange medium on the tank body 1 in the lateral direction, making the heat exchange process more stable and reliable.
[0041] High thermal conductivity composite phase change material 6 is made of phase change material and high thermal conductivity adsorption material. The new material high thermal conductivity composite phase change material 6 has both the excellent thermal conductivity of high thermal conductivity adsorption material and the high heat storage and energy storage characteristics of phase change material.
[0042] The phase change material is one or more of paraffin, stearic acid, lauric acid or capric acid;
[0043] The high thermal conductivity adsorption material is one or more of expanded graphite and carbon nanotubes;
[0044] The preparation method of the high thermal conductivity composite phase change material 6 includes the following specific steps:
[0045] S1: Weigh a certain amount of phase change material and high thermal conductivity adsorption material, heat them together to above the phase change temperature of the phase change material, until the phase change material is completely melted into a liquid to form a mixture, and then stir the mixture at a constant speed for 10 minutes;
[0046] S2: Place the mixture in a pressure tank, set the working temperature of the pressure tank to be higher than the phase change temperature of the phase change material, and extract the air in the pressure tank through a vacuum drying pump until the pressure reaches a vacuum degree of 100 kPa, and then maintain it for 5 minutes;
[0047] S3: Use the gas booster pump to boost the pressure tank. When the pressure reaches the normal pressure state, that is, the air pressure is 1Mpa, maintain it for 5 minutes;
[0048] S4; stop heating, the mixture will gradually cool down, and after the phase change material in the mixture is completely solidified, a high thermal conductivity composite phase change material 6 can be obtained.
[0049] During use: the heat exchange medium is injected into the tank body 1 through the heat exchange medium inlet 7. After flowing into the first heat medium buffer bin 10, the heat exchange medium flows evenly and smoothly into the double-layer spirally wound heat exchange pipe 5. In the heat storage bin 4, the heat exchange medium absorbs the heat stored in the surrounding high thermal conductivity composite phase change material 6 in the heat exchange pipe 5 and flows at a uniform speed until it flows into the second heat medium buffer bin 11 and finally flows out of the tank body 1 through the heat exchange medium outlet 8, completing the entire heat exchange process.
[0050] During heat exchange, the heat exchange medium is injected into the tank body 1 from the heat exchange medium inlet 7. Due to the setting of the double-layer spirally wound heat exchange pipe 5, the heat exchange medium's travel in the heat storage tank is lengthened in a limited space, and the heat exchange time with the high thermal conductivity composite phase change material 6 is improved. Therefore, the heat stored in the high thermal conductivity composite phase change material 6 in the heat storage tank can be fully absorbed. When heat energy needs to be released, the valve of the heat exchange medium outlet 8 port is opened, and the heat exchange medium can carry the stored heat and transfer it to the external system.
[0051] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.
Claims
1. A high thermal conductivity composite phase change filled heat storage tank for use in a solar heating system, comprising a tank body (1), characterized in that: A horizontal heat exchange top plate (2) is fixedly provided at the upper end of the interior of the tank body (1), a horizontal heat exchange bottom plate (3) is fixedly provided at the lower end of the interior of the tank body (1), a heat storage bin (4) is provided between the heat exchange top plate (2) and the heat exchange bottom plate (3), and a plurality of heat exchange pipes (5) are provided in the heat storage bin (4); The heat storage bin (4) is filled with a high thermal conductivity composite phase change material (6); A heat exchange medium inlet (7) is fixedly provided at the top end of the tank body (1), and a heat exchange medium outlet (8) is fixedly provided at the bottom end of the tank body (1); A plurality of support frames (9) are fixedly provided at the lower end of the side wall of the tank body (1).
2. The high thermal conductivity composite phase change filled heat storage tank for a solar heating system according to claim 1, characterized in that: There are two heat exchange medium inlets (7) arranged oppositely at the top end of the tank body (1), and there are two heat exchange medium outlets (8) arranged oppositely at the bottom end of the tank body (1).
3. The high thermal conductivity composite phase change filled heat storage tank for solar heating system according to claim 2, characterized in that: A first heat medium buffer bin (10) is provided between the upper end of the heat exchange top plate (2) and the interior of the tank body (1), and a second heat medium buffer bin (11) is provided between the lower end of the heat exchange bottom plate (3) and the interior of the tank body (1).
4. The high thermal conductivity composite phase change filled heat storage tank for a solar heating system according to claim 3, characterized in that: The heat exchange medium inlet (7) connects the first heat medium buffer tank (10) with the outside of the tank body (1), and the heat exchange medium outlet (8) connects the second heat medium buffer tank (11) with the outside of the tank body (1).
5. The high thermal conductivity composite phase change filled heat storage tank for solar heating system according to claim 1, characterized in that: The heat exchange pipe (5) comprises a plurality of inner ring bends (501) and outer ring bends (502), wherein the inner ring bends (501) and the outer ring bends (502) are staggered and equidistantly spirally wound from the inside to the outside, and the spiral directions of the inner ring bends (501) and the outer ring bends (502) are opposite.
6. The high thermal conductivity composite phase change filled heat storage tank for a solar heating system according to claim 1, characterized in that: There are three support frames (9) in total. The top ends of the support frames (9) are fixedly arranged at equal distances on the side walls of the bottom of the tank body (1). The bottoms of the support frames (9) are fixedly connected to the ground. The three support frames (9) are arranged at equal distances in the form of an equilateral triangle.