Adsorbent particles and adsorption bed of adsorption refrigeration system

Abstract

This invention discloses an adsorbent particle for use in an adsorption refrigeration system, comprising an adsorbent body with through-holes. The outer surface of the adsorbent body and the inner wall of the through-holes both form adsorption surfaces. Using adsorbent particles with through-holes not only increases the overall diameter of the adsorbent particle, facilitating its positional control, but also improves mass and heat transfer performance. In summary, this adsorbent particle effectively solves the problem of poor mass transfer caused by excessively large adsorbent particles in an adsorption bed. This invention also discloses an adsorption bed comprising the aforementioned adsorbent particles.

Description

Technical Field

[0001] This invention relates to the field of adsorption technology, and more specifically, to an adsorbent particle, and also to an adsorption bed of an adsorption refrigeration system. Background Technology

[0002] The adsorption bed includes an adsorbent and may also be provided with a heat exchange channel, in which the adsorbent and the heat exchange channel are in thermally conductive contact, so that the heat exchange fluid in the heat exchange channel can transfer heat to the adsorbent, and then to the adsorbate in the adsorbent.

[0003] At low temperatures, adsorbents can adsorb or / and bind to gaseous adsorbates. This can be a physical change, such as the gaseous working fluid changing into a liquid state to be adsorbed onto the adsorbent; or a chemical change, where the adsorbate chemically binds to the adsorbent, resulting in the adsorption of the adsorbate. At high temperatures, the adsorbent can absorb heat to generate a gaseous adsorbate, which is then released. This process is the reverse of the above; it can be a change from liquid to gas or a chemical change to release the gaseous working fluid.

[0004] In the process of realizing this invention, the inventors discovered at least the following problems in the prior art: the adsorbent can be laid flat in a layer or scattered in a cage structure. When placed in a cage structure, the pore size of the cage structure cannot be too small due to manufacturing process issues. This requires the use of adsorbent particles with a relatively large particle size. However, if the diameter of the adsorbent particles is too large, it will lead to poor mass transfer and heat transfer effects of the adsorbent particles. Summary of the Invention

[0005] In view of this, the first objective of the present invention is to provide an adsorbent particle that can effectively solve the problem of poor mass transfer caused by excessively large adsorbent particles in an adsorption bed. The second objective of the present invention is to provide an adsorption bed comprising the above-mentioned adsorbent particles.

[0006] To achieve the first objective mentioned above, the present invention provides the following technical solution: An adsorbent particle for use in an adsorption refrigeration system includes an adsorbent body, wherein the adsorbent body is provided with a through hole, and the outer surface of the adsorbent body and the inner wall of the through hole both form an adsorption surface.

[0007] In the aforementioned adsorbent particles, multiple particles can be randomly placed within a cavity during use, closely packed together. When adsorption is required, both the outer surface of the adsorbent body and the inner wall of the through-holes can adsorb the working fluid. The gaseous working fluid can flow smoothly within the through-holes, ensuring effective adsorption on the inner wall. Conversely, when desorption is required, the gaseous working fluid can desorb from both the outer surface of the adsorbent body and the inner wall of the through-holes. The desorbed gaseous working fluid can flow smoothly within the through-holes for rapid discharge. Furthermore, the gaseous working fluid can enter from one end of the through-hole and exit from the other, significantly improving mass transfer. Additionally, since the through-holes penetrate the entire adsorbent body, excessively long gaps in the adsorbent's structure are avoided, further enhancing adsorption efficiency. Simultaneously, the shortened heat transfer path within the adsorbent improves heat transfer efficiency. In summary, using adsorbent particles with through-pores not only increases the overall diameter of the adsorbent particles, facilitating their placement, but also improves mass and heat transfer performance. Therefore, these adsorbent particles effectively address the problem of poor mass transfer caused by excessively large adsorbent particles in adsorption beds.

[0008] In some technical solutions, the ratio of the depth to the diameter of the through hole is between 0.1 and 10.

[0009] In some technical solutions, the widest span of the projection surface of the adsorbent body in the depth direction of the through hole is between 1.5 and 4 times the diameter of the through hole.

[0010] In some technical solutions, the adsorbent body is a tubular structure, and the through hole is the cavity of the tubular structure.

[0011] In some technical solutions, the adsorbent body is a spherical structure.

[0012] In some technical solutions, the adsorbent body is a mixture of adsorbent powder and metal powder.

[0013] In some technical solutions, the adsorbent body includes foamed metal and adsorbent attached to the foamed metal.

[0014] In some technical solutions, the diameter of the through hole is between 0.5 mm and 5 mm.

[0015] To achieve the second objective mentioned above, the present invention also provides an adsorption bed for an adsorption refrigeration system. This adsorption bed includes any of the aforementioned adsorbent particles, a cage-like frame, and heat transfer tubes passing through the cavity of the cage-like frame. Multiple adsorbent particles are placed within the cavity of the cage-like frame. Since the aforementioned adsorbent particles possess the aforementioned technical effects, the adsorption bed containing these adsorbent particles should also possess corresponding technical effects.

[0016] In some technical solutions, the cage-shaped frame contains spherical adsorbent particles and cylindrical adsorbent particles. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the tubular adsorbent particles provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the adsorbent particles in the image; Figure 3 This is a schematic diagram of the structure of the bead-shaped adsorbent particles provided in an embodiment of the present invention; Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of the adsorbent particles in the image; Figure 5 for Figure 3 A schematic diagram of the arrangement of adsorbent particles in the image.

[0019] The following labels are shown in the attached diagram: Adsorbent body 1, through hole 2; outer surface 11, inner hole wall 21. Detailed Implementation

[0020] This invention discloses an adsorbent particle to effectively solve the problem of poor mass transfer caused by excessively large adsorbent particles in an adsorption bed.

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-5 , Figure 1 This is a schematic diagram of the structure of the tubular adsorbent particles provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the adsorbent particles in the image; Figure 3 This is a schematic diagram of the structure of the bead-shaped adsorbent particles provided in an embodiment of the present invention; Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of the adsorbent particles in the image; Figure 5 for Figure 3 A schematic diagram of the arrangement of adsorbent particles in the image.

[0023] In some embodiments, an adsorbent particle is provided for primary application in the adsorption bed of an adsorption refrigeration system. The adsorbent needs to have the function of adsorbing a gaseous working substance; specifically, it should be able to desorb the gaseous working substance when heated to a first preset temperature, and adsorb the gaseous working substance when cooled to a second preset temperature. The adsorption of the gaseous working substance by the adsorbent can be based on physical or chemical principles. The adsorbent itself has tiny pores to allow the gaseous working substance to penetrate deeper into the adsorbent. Similarly, the adsorbent needs to exchange heat with the outside, thereby exchanging heat with the working substance. During desorption, heat is absorbed from the outside to transfer heat to the working substance, causing the gaseous working substance to be desorbed; during adsorption, when the gaseous working substance binds to the adsorbent, heat is released, and this released heat is transferred to the outside through the adsorbent.

[0024] The adsorbent particles, a type of granular structure, generally have an outer diameter of no more than 5 cm, typically between 0.1 cm and 1 cm. However, they can be smaller or larger than 1 cm. When the working medium is water and the adsorption principle is physical adsorption, the diameter of the adsorbent particles is generally between 0.1 cm and 1 cm. The adsorbent particles can be spherical, blocky, or other shapes; there are no limitations on this. In use, the adsorbent particles can be laid flat on a tray, or they can be confined within a cage-like structure.

[0025] To facilitate heat input during desorption and heat removal during adsorption, a heat transfer structure is typically incorporated. Each adsorbent particle engages with this structure through direct or indirect thermal contact. When the adsorbent particles are relatively small, some particles will directly contact the heat transfer structure for direct heat transfer, while others will indirectly connect to the structure via the aforementioned contact, resulting in indirect heat transfer. This heat transfer structure can be exemplified by a heat transfer tube, which may alternately circulate a high-temperature fluid for desorption and a low-temperature fluid for adsorption. Alternatively, the heat transfer structure can be a solid structure.

[0026] The adsorbent body 1 of the adsorbent particles is a monolithic structure. It may contain only the adsorbent material, or other materials may be added to facilitate internal heat transfer. For example, the adsorbent body 1 can be a particle structure made solely of silica gel, a particle structure made solely of aluminum phosphate, or a particle structure made from both silica gel and aluminum phosphate. In this case, the adsorbent body 1 only contains the adsorbent material, with silica gel and aluminum phosphate being the same adsorbent material. Alternatively, the adsorbent body 1 can be made from a composite material containing both metal powder and adsorbent powder, in which case the metal powder enhances heat transfer.

[0027] In some embodiments, the adsorbent body 1 is provided with through holes 2, allowing the gaseous adsorbent working fluid to flow along the through holes 2. It should be noted that the adsorbent body 1 can generally have multiple through holes 2, or only one. When multiple through holes 2 are provided, they can be arranged in a crisscrossing or parallel configuration. Considering the small size of the adsorbent particles themselves, providing too many through holes 2 may affect the strength; therefore, only one through hole 2 can be provided. The size of the through hole 2 cannot be too small, otherwise it will not achieve a good mass transfer effect. Generally, the size of the through hole 2 should be significantly larger than the tiny gaps in the adsorbent used to adsorb the working fluid. Generally, the pore diameter (e.g., diameter) of the through hole 2 should be between 0.5 mm and 5 mm. If the pore diameter is too small, the mass transfer effect will be poor; if the pore diameter is too large, the proportion of adsorbent per unit volume will be too small, resulting in insufficient adsorption efficiency. The cross-section of the through hole 2 along the extending direction can be equal or unequal, and can be a cylindrical hole, a trumpet-shaped hole, a square hole; it can be a straight hole, a curved hole, etc.

[0028] The through-hole configuration refers to the fact that both ends of the hole are open and connected internally, forming a drainage channel inside. This allows the gaseous adsorbent to enter from one end of the through-hole 2 and flow out from the other end, thus achieving a drainage effect for the gaseous adsorbent.

[0029] The outer surface 11 of the adsorbent body 1 and the inner wall 21 of the through hole 2 both form adsorption surfaces. An adsorption surface refers to a surface capable of adsorbing gaseous working fluid, such as an opening with tiny slits for adsorbing the working fluid. The outer surface 11 of the adsorbent body 1 refers to the surface facing away from the center, while the surface of the through hole 2 is generally not part of the outer surface 11 of the adsorbent body 1. For example, for a tubular adsorbent body 1, the outer tube wall and the tube end face are both outer surfaces 11 of the adsorbent body 1. The formation of adsorption surfaces on the surface of the adsorbent body 1 does not require all surfaces to form adsorption surfaces; it is permissible for only a portion of the outer surface 11 to form adsorption surfaces, such as most of the outer surface 11.

[0030] The inner wall surface 21 of the through hole 2 forms an adsorption surface. This can be the entire hole wall surface or only a portion of it, such as the majority of the hole wall surface being adsorption surface. By forming an adsorption surface on the inner wall surface 21 of the through hole 2, the gaseous working fluid can combine with the adsorbent when flowing through the through hole 2, improving adsorption efficiency and facilitating mass transfer.

[0031] In the aforementioned adsorbent particles, during use, multiple adsorbent particles can be randomly placed in a cavity, closely attached to each other. When adsorption is required, both the outer surface 11 of the adsorbent body 1 and the inner wall 21 of the through-hole 2 can adsorb the working fluid. The gaseous working fluid can flow smoothly within the through-hole 2, ensuring the adsorption effect of the inner wall 21. When desorption is required, both the outer surface 11 of the adsorbent body 1 and the inner wall 21 of the through-hole 2 can desorb the gaseous working fluid. The desorbed gaseous working fluid can flow smoothly within the through-hole 2 for rapid discharge. Furthermore, the gaseous working fluid can also enter from one end of the through-hole 2 and exit from the other end, significantly improving mass transfer. Additionally, since the through-hole 2 extends through the adsorbent body 1, it avoids excessively long extensions of the tiny gaps in the adsorbent, thus improving the adsorption effect. Simultaneously, the shorter heat transfer path within the adsorbent enhances heat transfer efficiency. In summary, using adsorbent particles with through-holes 2 not only increases the overall diameter of the adsorbent particles, facilitating their placement, but also improves mass and heat transfer performance. Therefore, these adsorbent particles effectively address the problem of poor mass transfer caused by excessively large adsorbent particles in an adsorption bed.

[0032] In some embodiments, the through-hole 2 should not be too large or too small, and it also serves as a mass transfer channel. Generally, the depth-to-diameter ratio of the through-hole 2 should not be too large. If it is too large, the mass transfer channel path will be too long, resulting in large pressure changes and potential flow problems for the gaseous adsorbent, especially along the pore depth direction. This could lead to a significant increase in the gaseous adsorbent during desorption and a significant decrease in the adsorbed gaseous adsorbent, resulting in a large pressure drop and hindering the flow of the gaseous adsorbent. Conversely, the depth-to-diameter ratio of the through-hole 2 should not be too small. If it is too small, the adsorption efficiency will decrease, as too much space will be occupied by the through-hole 2, reducing the adsorbent content. Furthermore, the excess cavity in the through-hole 2 will be wasted. Therefore, the depth-to-diameter ratio of the through-hole 2 can be between 0.1 and 10. For example, for a cylindrical through-hole 2, its axial length is between 0.1 and 10 times its diameter.

[0033] It should be noted that the depth of the through hole 2 refers to the extension length from one end of the through hole 2 to the other end. For a straight through hole 2, its extension length is equal to the straight distance between the two ends. For a curved through hole 2, its extension length is greater than the straight distance between the two ends. The extension length should be the length of its extension path, which can be the length of the center line between the two ends.

[0034] For the diameter of the through hole 2, such as a cylindrical hole, the diameter can be its length. For a hole with a rectangular cross-section, the diameter refers to the distance between the diagonals of the rectangular hole. For a hole with an irregular cross-section, the straight-line distance between the two farthest points can be used as its diameter. For a through hole 2 whose cross-section changes from one end to the other, its diameter can be the average value of all cross-sections, the diameter at the smallest cross-section, or the diameter at the largest cross-section; the specific value can be determined by comparison as needed.

[0035] In some embodiments, the through-hole 2, relative to the overall size of the adsorbent body 1, should not be too small. If it is too small, the mass transfer effect of the internal adsorption surface will be poor; if it is too large, the adsorbent content will be low, affecting the mass transfer efficiency. Therefore, it is preferable that the widest span of the projected surface of the adsorbent body 1 in the depth direction of the through-hole 2 is between 1.5 and 4 times the diameter of the through-hole 2, such as twice. For example, for cylindrical adsorbent particles, the outer wall diameter is between 1.5 and 4 times the lumen diameter. For spherical adsorbent particles, the diameter of the outer surface 11 profile is between 1.5 and 4 times the lumen diameter.

[0036] In some embodiments, as shown in the appendix Figure 1 , 2 As shown, the adsorbent body 1 can be a tubular structure, and the through-hole 2 is a tubular cavity. This structure is easy to mold; for example, it can be formed by spraying the adsorbent solution onto a linear support structure, allowing it to solidify, detach from the linear support structure, and then cutting it to the required length. Alternatively, it can be molded. In an adsorption bed, multiple adsorbent particles are typically arranged, and these particles can have different lengths. When multiple cylindrical particles are randomly scattered, they are staggered and closely attached to each other, ensuring that most of the cavities are open at both ends, thus achieving a substantial mass transfer effect.

[0037] In some embodiments, as shown in the appendix Figure 3 , 4As shown, the adsorbent body 1 can be a spherical structure with a through-hole 2 in the middle, similar to a threaded bead structure. Spherical particles are easier to mold and the size of the adsorbent particles is easier to control. They can also be molded by casting. When multiple spherical particles are scattered, large pores do not appear, thus allowing for good control of compactness and ensuring a more uniform structure throughout.

[0038] As attached Figure 5 As shown, this is a schematic diagram of the random placement of multiple spherical adsorbent particles. During the random placement process, although the orientation of the through holes 2 is not consistent, they can generally form a mass transfer direction that conforms to the direction of the current view, so as to ensure the effective mass transfer of most of the through holes 2.

[0039] In some embodiments, in order to better ensure heat transfer inside the adsorbent body 1, the adsorbent body 1 can be a mixed structure of adsorbent powder and metal powder, wherein the adsorbent powder plays an adsorption role, and the metal powder can accelerate heat transfer to ensure the heat transfer effect.

[0040] The proportion of metal powder added to the adsorbent powder cannot be too high; too high a proportion will result in low adsorption efficiency, while too low a proportion will result in poor adsorption performance. Furthermore, to improve the overall mass and heat transfer effect, the adsorbent powder can be located only on the surface of the adsorbent body 1 to increase heat transfer with other adsorbent particles. The inner wall of the through-hole 2 does not need to be in thermal contact with other adsorbent particles, therefore it does not require heat transfer and can therefore contain no metal powder or a small amount of metal powder.

[0041] In some embodiments, to better ensure heat transfer within the adsorbent body 1, the adsorbent body 1 may include a foamed metal and an adsorbent attached to the foamed metal. The foamed metal may be, for example, foamed copper or foamed aluminum. In this case, the foamed metal may have a block structure, such as a plate structure, and multiple through holes 2 may be arranged along the plate's extension direction.

[0042] It should be noted that, in order to improve heat transfer between adsorbent particles, a portion of the metal structure on the foam metal surface can be exposed to facilitate contact between them. A layer of adsorbent particles can be attached to the inner wall of the through-hole 2.

[0043] Based on the adsorbent particles provided in the above embodiments, the present invention also provides an adsorption bed for use in an adsorption refrigeration system. The adsorption bed includes any of the adsorbent particles described in the above embodiments, comprising a cage-like frame and heat transfer tubes penetrating the cavity of the cage-like frame. Multiple adsorbent particles are placed within the cavity of the cage-like frame, wherein the heat transfer tubes are used for alternating flow of a high-temperature fluid for desorption and a low-temperature fluid for adsorption. Since this adsorption bed uses the adsorbent particles described in the above embodiments, the beneficial effects of this adsorption bed are explained in the above embodiments.

[0044] The cage-like frame can contain two different shapes of adsorbent particles. This mixed arrangement prevents the adsorbent particles from being too tightly packed together, which could lead to poor mass transfer. Specifically, the cage-like frame can contain both spherical and cylindrical adsorbent particles, which can be mixed together. The number of spherical adsorbent particles can be equal to the number of cylindrical adsorbent particles.

[0045] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An adsorbent particle for use in an adsorption refrigeration system, characterized in that, The adsorbent body (1) is provided with a through hole (2), and the outer surface (11) of the adsorbent body (1) and the inner wall (21) of the through hole (2) are both formed as adsorption surfaces.

2. The adsorbent particles according to claim 1, characterized in that, The depth-to-diameter ratio of the through hole (2) is between 0.1 and 10.

3. The adsorbent particles according to claim 2, characterized in that, The widest span of the projection surface of the adsorbent body (1) in the depth direction of the through hole (2) is between 1.5 and 4 times the diameter of the through hole (2).

4. The adsorbent particles according to claim 1, characterized in that, The adsorbent body (1) is a tubular structure, and the through hole (2) is the cavity of the tubular structure.

5. The adsorbent particles according to claim 1, characterized in that, The adsorbent body (1) has a spherical structure.

6. The adsorbent particles according to any one of claims 1-5, characterized in that, The adsorbent body (1) is a mixture of adsorbent powder and metal powder.

7. The adsorbent particles according to any one of claims 1-5, characterized in that, The adsorbent body (1) includes foam metal and adsorbent attached to the foam metal.

8. The adsorbent particles according to claim 1, characterized in that, The diameter of the through hole (2) is between 0.5 mm and 5 mm.

9. An adsorption bed for an adsorption refrigeration system, comprising a cage-type frame and heat transfer tubes passing through the cavity of the cage-type frame, characterized in that, It also includes adsorbent particles as described in any one of claims 1-8, wherein a plurality of the adsorbent particles are placed in the cavity of the cage-shaped frame.

10. The adsorption bed according to claim 9, characterized in that, The cage-shaped frame contains spherical adsorbent particles and cylindrical adsorbent particles.

Images