Adsorption bed and its heat transfer means

Abstract

This invention discloses an adsorption component for an adsorption bed, including a heat exchange channel wall for forming a heat exchange channel. A foam support structure layer is provided on the side of the heat exchange channel wall away from the heat exchange channel. Adsorbent is disposed in the pores of the foam support structure layer. The thermal conductivity of the solid structure of the foam support structure layer is higher than that of the adsorbent. Because the thermal conductivity of the solid structure of the foam support structure layer is higher than that of the adsorbent, the thermal resistance between adsorbent molecules is reduced. Therefore, this heat transfer component of the adsorption bed can effectively solve the problem of poor heat transfer performance in heat transfer components. This invention also discloses an adsorption bed including the above-mentioned heat transfer component.

Description

Technical Field

[0001] This invention relates to the field of adsorption technology, and more specifically, to a heat transfer component for an adsorption bed, and to an adsorption bed including the aforementioned heat transfer component. Background Technology

[0002] At low temperatures, the adsorbent in an adsorption bed 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 gaseous adsorbates, which are 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.

[0003] During the desorption and / or adsorption stages, a heat exchange fluid is required to exchange heat with the adsorbent in the adsorption chamber. Therefore, an adsorption chamber is formed within the adsorption bed, with heat transfer channels extending through it. The fluid in these channels can transfer heat with the adsorbent in the adsorption chamber. Simultaneously, a mass transfer cavity is also provided within the adsorption chamber to allow the gaseous adsorbent to flow through it. During the adsorption stage, the gaseous adsorbent formed in the evaporator is transported to the mass transfer cavity, where it contacts and is received by the adsorbent. During the desorption stage, the adsorbent desorbs the gaseous adsorbent, which enters the mass transfer cavity and then exits the condenser from the outlet of the mass transfer cavity.

[0004] In the process of realizing this invention, the inventors discovered that the prior art has at least the following problems: the adsorbent needs to exchange heat with the heat exchange channel, while the adsorption working fluid needs to be combined with the adsorbent. How to efficiently transfer mass and heat has become an urgent problem for adsorption beds. Summary of the Invention

[0005] In view of this, the first objective of the present invention is to provide a heat transfer component for an adsorption bed that can effectively solve the problem of poor heat transfer performance of current heat transfer components. The second objective of the present invention is to provide an adsorption bed including the above-mentioned heat transfer component.

[0006] To achieve the first objective mentioned above, the present invention provides the following technical solution: An adsorption component for an adsorption bed includes a heat exchange channel wall for forming a heat exchange channel. The heat exchange channel wall has a foam support structure layer on the side away from the heat exchange channel. Adsorbent is disposed in the pores of the foam support structure layer. The thermal conductivity of the solid structure of the foam support structure layer is higher than that of the adsorbent.

[0007] In the adsorption components of the aforementioned adsorption bed, at least a portion of the adsorbent is placed within the foam support structure layer, enhancing the internal structural strength of the adsorption layer. Because the foam support structure layer is porous, it can be filled with adsorbent, increasing the lateral depth and allowing for greater heat transfer to the adsorbent. Furthermore, heat from the heat exchange fluid is transferred to the walls of the heat exchange channels and conducted along the solid portion of the foam support structure layer within the adsorption layer, reducing the thermal resistance between the heat exchange channel walls and the adsorbent. The thermal conductivity of the solid structure of the foam support structure layer is higher than that of the adsorbent, thus reducing the thermal resistance between the adsorbents. In summary, the heat transfer components of this adsorption bed effectively solve the problem of poor heat transfer performance in traditional heat transfer components.

[0008] In some technical solutions, the heat exchange channel wall is a plate structure, and the heat exchange channel wall and the foam support structure layer attached to one side of the heat exchange channel wall are combined to form a composite plate structure. Multiple composite plate structures are arranged side by side along the thickness direction, and adjacent composite plate structures are arranged in opposite directions to form mass transfer channels and heat exchange channels alternately.

[0009] In some technical solutions, the heat exchange channel wall is welded to the foam support structure layer.

[0010] In some technical solutions, the heat exchange channel wall is integrally formed and connected with the foam support structure layer.

[0011] In some technical solutions, the foam support structure layer is made of foamed copper, the heat exchange channel wall is made of copper, and the foam support layer and the heat exchange channel wall are vacuum brazed.

[0012] In some technical solutions, one side of the foam support structure layer is thermally connected to the wall of the heat exchange channel, and the other side is attached with an adsorbent layer.

[0013] In some technical solutions, the thickness of the adsorbent layer is no more than one-fifth of that of the foam support structure layer, and the layer thickness is no less than the adhesion thickness of the adsorbent in the pores of the foam support structure layer.

[0014] In some technical solutions, the porosity of the foam support structure layer gradually increases along the direction away from the heat exchange channel wall.

[0015] In some technical solutions, the foam support structure layer is made of copper foam or aluminum foam.

[0016] To achieve the second objective mentioned above, the present invention also provides an adsorption bed, which includes any of the aforementioned heat transfer components and a chamber, wherein the heat transfer component is disposed in the chamber. Since the aforementioned heat transfer components possess the above-mentioned technical effects, the adsorption bed having such heat transfer components should also possess corresponding technical effects. 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 adsorption component of the adsorption bed provided in an embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of an adsorption component for another adsorption bed provided in an embodiment of the present invention.

[0019] The following labels are shown in the attached diagram: 1. Heat transfer tube; 2. Foam support structure layer; 3. Adsorbent; 4. Adsorbent layer; 5. Heat exchange fluid; 6. Mass transfer cavity; 7. Composite plate structure. Heat transfer channel 11, heat exchange channel wall 12. Detailed Implementation

[0020] This invention discloses a heat transfer component for an adsorption bed, which can effectively solve the problem of poor heat transfer performance of current heat transfer components.

[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 1-2 , Figure 1 This is a schematic diagram of the adsorption component of the adsorption bed provided in an embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of an adsorption component for another adsorption bed provided in an embodiment of the present invention.

[0023] In some embodiments, this embodiment provides an adsorption component for an adsorption bed. Specifically, the adsorption component mainly includes a heat exchange channel wall 12, a foam support structure layer 2, and an adsorbent 3. The adsorption bed is primarily the adsorption bed of an adsorption refrigeration system.

[0024] The heat exchange channel wall 12 forms a heat exchange channel, which can be a parallel channel or a tubular channel. Therefore, the heat exchange channel wall 12 can be the wall of a heat exchange tube or a partition structure. One side of the heat exchange channel wall 12 faces the heat exchange channel, and the other side faces the mass transfer cavity 6. The heat exchange channel is used for the flow of heat exchange fluid 5, while the mass transfer cavity 6 is used for the flow of a gaseous adsorbent working fluid that cooperates with the adsorbent 3.

[0025] When a high-temperature fluid, namely the heat exchange fluid 5 used for desorption, flows in the heat exchange channel, the high-temperature fluid heats the adsorbent 3 so that the adsorbent 3 desorbs the gaseous adsorbent working medium, and the gaseous adsorbent working medium enters the mass transfer chamber 6, and then flows out from the mass transfer chamber 6 and into the connected condenser.

[0026] When a low-temperature fluid, namely the heat exchange fluid 5 used for adsorption, flows in the heat exchange channel, the low-temperature fluid absorbs heat from the adsorbent 3 so that the adsorbent 3 can adsorb the gaseous adsorbent in the mass transfer chamber 6. At this time, the mass transfer chamber 6 will form a negative pressure to adsorb the gaseous adsorbent in the evaporator, so that the gaseous adsorbent will be continuously evaporated in the evaporator.

[0027] A foam support structure layer 2 is provided on the side of the heat exchange channel wall 12 away from the heat exchange channel, wherein heat can be transferred between the foam support structure layer 2 and the heat exchange channel wall 12. The foam support structure layer 2 forms foam-type pores, and an adsorbent 3 is arranged in the foam-type pores. The adsorbent 3 fills the foam pores and transfers heat between itself and the solid structure constituting the foam pores, and then between itself and the heat exchange channel wall 12.

[0028] The foam support structure layer 2 refers to the structure that forms the foam-like pores, and the solid part of the structure is made of a thermally conductive material to create a larger surface area for direct heat transfer with the adsorbent 3. The foam support structure layer 2 can be a foamed metal layer, or it can be made of other materials with high thermal conductivity. Specifically, it is preferred that the foam support structure layer 2 be foamed copper or foamed aluminum.

[0029] The thermal conductivity of the solid structure of the foam support layer 2 is higher than that of the adsorbent 3, meaning that the thermal conductivity of the material used to make the foam support layer 2 is higher than that of the adsorbent 3. For details on how to manufacture the foam support layer 2, refer to existing methods for manufacturing foam metals. The solid structure of the foam support layer 2 forms the aforementioned foam-like pores.

[0030] Adsorbent 3 forms an adsorbent-working-medium pair with the working medium. One working medium can correspond to multiple adsorbent 3 materials; therefore, adsorbent layer 4 can include multiple adsorbent 3 materials, such as aluminum phosphate and silica gel. The adsorbent 3 and the working medium can form a physical adsorbent-working-medium pair or a chemical adsorbent-working-medium pair. For example, when the mass transfer chamber 6 includes multiple working media, adsorbent layer 4 can include both physical and chemical adsorbents 3. Considering that some chemical adsorption can alter the physical properties of the adsorbent 3, leading to a decrease in fixation effect, the use of such chemical adsorbents 3 can be avoided when it is necessary to maintain the physical properties.

[0031] The adsorbent 3 is arranged in the pores of the foam support structure layer 2 to form an adsorption layer. It generally does not completely fill the foam support structure layer 2, but leaves some gaps for mass transfer. Generally, the adsorbent 3 can be attached to the pore walls of the foam support structure layer 2 in a layered structure, in which case the adsorbent 3 can be a fine powder structure; or the adsorbent 3 can be arranged as particles filling the pores, with the pores formed between the particles serving as mass transfer pores. It should be noted that the adsorbent 3 arranged in the pores of the foam support structure layer 2 can mean that all of the adsorbent 3 is arranged in the pores of the foam support structure layer 2; or some of the adsorbent 3 is arranged in the foam support structure layer 2, while the others can be arranged in other locations.

[0032] During the desorption phase, heat is transferred from the high-temperature heat exchange fluid 5 to the heat exchange channel wall 12, and then from the heat exchange channel wall 12 to the adsorbent 3, causing the adsorbent 3 to desorb the gaseous adsorbent. The gaseous adsorbent is discharged from the side of the foam support structure layer 2 away from the heat exchange channel wall 12. During the adsorbent 3 phase, the gaseous adsorbent present on the side of the foam support structure layer 2 away from the heat exchange channel wall 12 enters the pores of the foam support structure layer 2 and is adsorbed by the adsorbent 3. During adsorption, heat is released and transferred to the support structure in the foam support structure layer 2. The heat is then transferred to the heat exchange channel wall 12 through the support structure of the foam support structure layer 2, where it is further carried away by the low-temperature fluid in the heat exchange channel.

[0033] In the above embodiments, at least a portion of the adsorbent 3 is placed within the foam support structure layer 2, enhancing the internal structural strength of the adsorption layer. Since the foam support structure layer 2 is a porous structure, it can be filled with adsorbent 3, increasing the lateral depth and allowing for heat transfer to more of the adsorbent 3. Furthermore, the heat from the heat exchange fluid 5 is transferred to the heat exchange channel wall 12 and conducted along the solid portion of the foam support structure layer 2 within the adsorption layer, reducing the thermal resistance between the heat exchange channel wall 12 and the adsorbent 3. The thermal conductivity of the solid structure of the foam support structure layer 2 is higher than that of the adsorbent 3, thus reducing the thermal resistance between the adsorbents 3. In summary, the heat transfer component of this adsorption bed effectively solves the problem of poor heat transfer performance.

[0034] In some embodiments, the heat exchange channel can be the cavity of a heat exchange tube, such as a round tube or a square tube. The heat exchange channel can also be a parallel flow channel with a parallel flow structure.

[0035] As attached Figure 2 As shown, to facilitate the arrangement of the aforementioned foam support structure layer 2, the heat exchange channel wall 12 is preferably a plate-shaped structure. Multiple heat exchange channel walls 12 are arranged side by side along the thickness direction of the plate-shaped structure. One side of the heat exchange channel wall 12 is attached to the foam support structure layer 2, facing the mass transfer chamber 6, while the other side of the heat exchange channel wall 12 is exposed, facing the chamber of the heat exchange channel. At this time, the heat exchange channel wall 12 and the foam support structure layer 2 attached to one side of the heat exchange channel wall 12 are stacked to form a composite plate structure 7, that is, one side of the composite plate structure 7 is the heat exchange channel wall 12, and the other side is the foam support structure layer 2.

[0036] Multiple composite plate structures 7 are arranged side by side along the thickness direction, with adjacent composite plate structures 7 arranged in opposite directions to form mass transfer channels and heat exchange channels alternately. The middle composite plate structure 7 has a foam support structure layer 2 on one side facing the mass transfer channel, and a heat exchange channel wall portion 12 on the other side facing the heat exchange channel, allowing alternating flow of high-temperature fluid for desorption and low-temperature fluid for adsorption. Along the thickness direction, the two side plate structures have a foam support structure layer 2 on their inner side; this plate structure can use the same structure as the aforementioned composite plate structure 7. The other plate structure does not have a foam metal structure layer on its outer side, thus it can be a single, bare plate.

[0037] The use of composite panel structure 7 facilitates manufacturing, especially the manufacturing of the aforementioned foam metal structure layer.

[0038] In some embodiments, the heat exchange channel wall 12 can be welded to the foam support structure layer 2. Specific welding methods include, for example, vacuum brazing: a welding fixture (commonly graphite fixtures) is required. A metal material with a lower melting point than the base material of the heat exchange channel wall 12 and the foam support structure layer 2 is used as the filler metal. The liquid filler metal wets the base material, fills the contact gap interface, and diffuses with the heat exchange channel wall 12 and the base material of the foam support structure layer 2 to achieve a connection. Note that during brazing, the heat exchange channel wall 12 should be positioned axially perpendicular to the horizontal plane, allowing the liquid filler metal to flow along the outer wall of the heat exchange tube during welding, effectively filling the contact interface and preventing excessive flow into the pores of the foam support structure. If the foam support structure layer 2 is foamed copper and the heat exchange channel wall 12 is pure copper, vacuum brazing is performed between the foam support layer and the heat exchange channel wall. The amorphous copper-phosphorus brazing filler metal has good wettability to pure copper. At a brazing temperature of 700°C and a holding time of 5 minutes, the brazing interface between the foamed copper and the pure copper substrate is smooth and tightly bonded, without any defects such as holes or cracks.

[0039] Of course, the heat exchange channel wall 12 and the foam support structure layer 2 can also be pressure welded: a welding fixture is needed to fix the foam support structure layer 2 to the outer wall of the heat exchange channel wall 12 and ensure that a certain pressure can be applied. The surface is placed in a vacuum or protective atmosphere furnace for heating, so that the tiny unevenness of the two welding surfaces produces microscopic plastic deformation, achieving close contact. Then, during heating and heat preservation, the atoms diffuse into each other to form a metallurgical connection.

[0040] Of course, the heat exchange channel wall 12 and the foam support structure layer 2 can also be fusion welded: a welding fixture is needed to heat the heat exchange channel wall 12 and the foam support structure layer 2 to locally melt them and form a molten pool. After the molten pool cools and solidifies, they are joined together. If necessary, the filler material (welding material) can be heated to assist.

[0041] In some embodiments, the heat exchange channel wall 12 can be integrally formed and connected with the foam support structure layer 2. That is, when metal powder mixed with foaming agent is attached to the heat exchange channel wall 12 and then sintered, the foaming agent evaporates, leaving pores, while the sintered metal powder and the heat exchange channel wall 12 are fused together to form an integral connection.

[0042] For example, on a board, a foam support structure layer 2 is obtained on one side by electrochemical deposition, while a heat exchange channel wall 12 is formed on the other side. At this time, the heat exchange channel wall 12 and the foam support structure layer 2 are integrally formed and connected.

[0043] The above method uses an integrated connection with low contact thermal resistance, which results in better heat distribution in the lateral direction and is more conducive to heat transfer.

[0044] In some embodiments, one side of the foam support structure layer 2 can be thermally connected to the heat exchange channel wall 12, and the other side can be covered with an adsorbent layer 4 to wrap the foam support structure layer 2, thereby avoiding energy waste on the side of the foam support structure layer 2 away from the heat exchange channel wall 12.

[0045] This adsorbent layer 4 should not be able to seal the pores of the foam support structure layer 2, so as to ensure the transfer of gaseous adsorbed working fluid between the pores and the mass transfer chamber 6. During desorption, heat in the heat exchange channel wall 12 is transferred to the foam support structure layer 2, and then from the foam support structure layer 2 to the adsorbent layer 4. During adsorption, the above process is reversed.

[0046] It should be noted that since the adsorbent layer 4 cannot effectively transfer heat, the thickness of the adsorbent layer 4 should not be too large. For example, the thickness of the adsorbent layer 4 should not exceed 1 mm to avoid having a long heat transfer path inside.

[0047] Specifically, the thickness of the adsorbent layer 4 can be no more than one-fifth of that of the foam support structure layer 2.

[0048] Furthermore, it is preferable that the thickness of the adsorbent layer 4 is not less than the adhesion thickness of the adsorbent 3 in the pores of the foam support structure layer 2. This is because the adsorbent layer 4 can also quickly obtain energy from the foam support structure layer 2, and it is more convenient to transfer mass with the mass transfer channel, so it can be appropriately thicker.

[0049] In some embodiments, considering the direction closer to the heat exchange channel wall 12: on the one hand, the structural entities in the foam support structure layer 2 need to transfer more heat, thus requiring a larger heat transfer cross-section; on the other hand, the difficulty of mass transfer between its pores and the outside is greater. Therefore, the porosity of the foam support structure layer 2 can be gradually increased along the direction away from the heat exchange channel wall 12; that is, the porosity of the foam support structure layer 2 gradually decreases towards the heat exchange channel wall 12, where porosity refers to volume ratio. Through the above arrangement, the proportion of structural entities in the foam support structure layer 2 is higher towards the heat exchange channel wall 12, resulting in better heat transfer, while the corresponding proportion of adsorbent 3 is lower, resulting in a smaller amount of adsorbent working fluid that needs to be transferred outward, thus lower mass transfer pressure. Through the above arrangement, better mass and heat transfer effects are achieved.

[0050] One specific method is to control the porosity along the thickness direction during molding. For example, in powder metallurgy, the foaming agent content can be gradually adjusted, resulting in a continuous increase in the porosity along the thickness direction.

[0051] Alternatively, the foam support structure layer 2 can include a first foam structure layer and a second foam structure layer, with the porosity of the first foam structure layer being greater than that of the second foam structure layer. In this case, the second foam structure layer can be located between the first foam structure layer and the heat exchange channel wall 12, so that the porosity of the foam support structure layer 2 gradually increases along the direction away from the heat exchange channel wall 12. In this case, welding connections can be used between the second foam structure layer and the first foam structure layer, and between the second foam structure layer and the heat exchange channel wall 12.

[0052] To ensure the effective containment of the adsorbent 3, the overall porosity of the foam support structure layer 2 is between 85% and 95%; similarly, the porosity of both the first foam structure layer and the second foam structure layer can be between 85% and 95%.

[0053] Based on the heat transfer components provided in the above embodiments, the present invention also provides an adsorption bed, which includes any one of the heat transfer components in the above embodiments, including a chamber, wherein the heat transfer component is disposed in the chamber. Since this adsorption bed uses the heat transfer components in the above embodiments, the beneficial effects of this adsorption bed are explained in the above embodiments.

[0054] Furthermore, the adsorption bed can be equipped with multiple heat transfer components as modular parts, evenly arranged in the adsorption bed chamber. In this case, each heat transfer component has a multi-port structure at both ends of its heat pipe 1, serving as a collector and a distributor, respectively.

[0055] 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.

[0056] 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 adsorption component for an adsorption bed, comprising a heat exchange channel wall (12) for forming a heat exchange channel, characterized in that, The heat exchange channel wall (12) is provided with a foam support structure layer (2) on the side away from the heat exchange channel. Adsorbent (3) is arranged in the pores of the foam support structure layer (2). The thermal conductivity of the solid structure of the foam support structure layer (2) is higher than that of the adsorbent (3).

2. The adsorption component of the adsorption bed according to claim 1, characterized in that, The heat exchange channel wall (12) is a plate structure, and the heat exchange channel wall (12) and the foam support structure layer (2) attached to one side of the heat exchange channel wall (12) are combined to form a composite plate structure (7). Multiple composite plate structures (7) are arranged side by side along the thickness direction, and adjacent composite plate structures (7) are arranged opposite to each other to form mass transfer channels and heat exchange channels.

3. The adsorption component of the adsorption bed according to claim 2, characterized in that, The heat exchange channel wall (12) is welded to the foam support structure layer (2).

4. The adsorption component of the adsorption bed according to claim 2, characterized in that, The heat exchange channel wall (12) is integrally formed and connected with the foam support structure layer (2).

5. The adsorption component of the adsorption bed according to claim 4, characterized in that, The foam support structure layer (2) is made of foamed copper, the heat exchange channel wall (12) is made of copper, and the foam support structure layer (2) and the heat exchange channel wall (12) are vacuum brazed together.

6. The adsorption component of the adsorption bed according to any one of claims 1-5, characterized in that, The foam support structure layer (2) is thermally connected to the heat exchange channel wall (12) on one side, and an adsorbent layer (4) is attached to the other side.

7. The adsorption component of the adsorption bed according to claim 6, characterized in that, The thickness of the adsorbent layer (4) is not higher than one-fifth of that of the foam support structure layer (2), and the thickness is not lower than the adhesion thickness of the adsorbent (3) in the pores of the foam support structure layer (2).

8. The adsorption component of the adsorption bed according to any one of claims 1-5, characterized in that, Along the direction away from the heat exchange channel wall (12), the porosity of the foam support structure layer (2) gradually increases.

9. The adsorption component of the adsorption bed according to claim 8, characterized in that, The foam support structure layer (2) is made of copper foam or aluminum foam.

10. An adsorption bed, comprising a chamber, characterized in that, It also includes the heat transfer member as described in any one of claims 1-9, wherein the heat transfer member is disposed in the chamber.

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