A compact heat storage and heat exchange device and a manufacturing method thereof

Abstract

The application relates to a compact heat storage and exchange device and a manufacturing method thereof. The heat storage and exchange device comprises micro-channel parallel flow flat tubes, small collecting pipes, large collecting pipes and phase change heat storage materials. The phase change heat storage materials are located between the micro-channel parallel flow flat tubes. The two ends of the parallel flow flat tubes are open and communicated with the small collecting pipes. The small collecting pipes are communicated with the large collecting pipes through connecting pipes. The phase change heat storage materials contain heat conduction skeletons to form composite phase change materials. The high-heat-conductivity direction of the composite phase change materials is consistent with the flow channel direction of the flat tubes. Compared with the prior art, the application optimizes the spatial layout of the phase change heat storage composite material microstructure and the heat exchange fluid flow channel, reduces the contact thermal resistance between the phase change heat storage composite material and the heat exchange flat tube, and can flexibly adjust the working mode and input / output power of the heat storage and exchange device by changing the connecting mode of the small collecting pipes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat storage and heat management, in particular to a compact heat storage and heat exchange device and a manufacturing method thereof. BACKGROUND

[0002] Heat storage technology can be widely applied in solar heat utilization, building energy saving, heat pump air conditioning and other energy storage technologies such as compressed air energy storage technology, which can effectively overcome the time intermittency and intensity instability of heat flow, realize the decoupling of heat supply and demand in time and intensity, and effectively match the supply and demand relationship. Heat storage technology includes sensible heat storage, latent heat storage and thermochemical heat storage, among which latent heat storage based on solid-liquid phase change is in the initial stage of commercial application, and still faces the problems of low power density caused by insufficient heat transfer performance and low energy density caused by non-compact device structure.

[0003] Existing heat transfer enhancement measures include using finned tube heat exchangers, plate-fin heat exchangers, filling phase change materials with metal foams, and adding heat conductive additives inside the phase change materials. These measures can improve the heat transfer coefficient to a certain extent, but face the problems of weight increase and insufficient heat transfer enhancement, which seriously restrict the energy density and power density of phase change heat storage devices. In addition, existing phase change heat storage and heat exchange devices are mostly single-fluid channels, which only allow one fluid to exchange heat with the phase change material, and cannot meet the situation of two or more fluids flowing at the same time, which greatly limits the application scenarios of heat storage and heat exchange devices. Although existing reports use multiple coils inside the phase change heat storage device to form multiple fluid heat exchange channels, the overall heat storage and heat transfer performance is poor due to unreasonable structure design.

[0004] Patent CN203731913U discloses a heat storage heat exchanger, the heat exchange rod of the heat exchanger is composed of fluid pipeline, aluminum fin plate and solid-liquid phase change heat storage material filled in the inner container, and the cold and hot fluid pipelines composed of two copper pipes are arranged in an arch shape and pass through the fin plates in a meandering manner. In the patent, the heat exchange of the cold and hot fluids is mostly carried out through the solid-liquid phase change material, and a small part is conducted through the fin plates between the cold and hot fluid pipes. Although the heat storage heat exchanger has the advantages of flexible separation or simultaneous performance of heat storage and heat exchange, simple manufacturing and the like, the use of the tubular fluid passage and the square shell leads to the problems of easy occurrence of heat storage dead zone, poor heat transfer capacity of the cold and hot fluids and the like, which limits the energy density and power density of the device. Similarly, patent CN221036983U discloses a serpentine pipe type phase change heat storage heat exchanger, which aims to realize high-efficiency heat exchange among the cold fluid, the hot fluid and the solid-liquid phase change material through the curved surface structure of the serpentine heat exchange pipe. The heat storage heat exchanger also uses the tubular fluid passage, and has the problem of unreasonable arrangement of the cold and hot fluid pipelines, which limits the energy density and power density of the device. Patent CN104215109A discloses a phase change energy storage device with a micro-channel heat exchanger, which is provided with finned ribs on the upper and lower flat tubes for strengthening heat transfer, and is provided with two independent collecting cavities in the connecting flat tube side collecting pipe, so that the fluid inlet and outlet are located on the same side of the flat tube, and the fluid flows back after entering the flat tube. The phase change energy storage device has the problems of complex heat transfer structure and large fluid flow resistance, and is not conducive to the arrangement of multiple fluid flows. SUMMARY

[0005] The present application aims to overcome at least one of the above-mentioned defects of the prior art, and provides a compact heat storage heat exchange device and a manufacturing method thereof. The compact heat storage heat exchange device has one or more fluid passages, and the fluid flows in the flat tube with micro-channels. The flat tube is filled with a composite phase change material with enhanced heat conduction (phase change heat storage material), and the orientation direction of the heat conduction skeleton (sheet-shaped high-thermal-conductivity material) in the composite phase change material is consistent with the flow direction in the flat tube, so as to ensure that the high-thermal-conductivity direction is consistent with the heat transfer direction. The effective thickness of the composite phase change material can be adjusted by adjusting the spacing between the flat tubes. Since the fluid passages are relatively independent, the fluid flow direction can be adjusted by adjusting the pipeline connection mode, and then the heat storage and release power can be adjusted. The present application optimizes the heat transfer and heat storage performance in space, improves the charging and discharging rate of the heat storage material, and can realize high energy density and high power density at the device level.

[0006] The object of the present application is achieved by the following technical solutions:

[0007] The first object of the present application is to provide a compact heat storage heat exchange device, which comprises:

[0008] Flat tube, the flat tube is a micro-channel parallel flow flat tube, which contains a plurality of parallel channels inside, and two ends are connected to small header pipes, the two ends of the flat tube are communicated with the side surfaces of the small header pipes to form a heat exchanger unit, and the small header pipes are communicated with the large header pipe through the connecting pipes;

[0009] Small header pipe, the side surface is provided with a slot, the parallel flow flat tube is inserted into the slot and welded, and the internal cross-sectional area of the small header pipe is greater than or equal to the sum of the cross-sectional areas of all flow channels inside the parallel flow flat tube;

[0010] Large header pipe, the side surface is provided with a hole, and the small header pipes are connected through the connecting pipes;

[0011] Phase change heat storage material, located between the micro-channel parallel flow flat tubes, containing a heat conduction skeleton (sheet-shaped high-thermal-conductivity material) inside to form a composite phase change material, and the high-thermal-conductivity direction of the composite phase change material is consistent with the flow channel (parallel channel) direction inside the flat tube.

[0012] The manufacturing method of the compact heat storage and heat exchange device comprises the following steps: firstly, assembling the parallel flow flat tube and two small header pipes to form a single heat exchanger unit; then, assembling a plurality of heat exchanger units; and then, connecting the heat exchanger units through the large header pipe in a certain manner to obtain a plurality of flat tube heat exchangers; and finally, compressing the composite phase change material particles or powder in the pre-prepared heat exchanger interlayer to form a shape, and the compression direction is parallel to the flat tube surface and perpendicular to the flat tube axis.

[0013] Further, the heat exchanger unit comprises two small header pipes and a flat tube; the two small header pipes are communicated with the two ends of the flat tube respectively; the small header pipe is a pipe with a slot on the side surface, and the side slot is communicated with the open end surface of the flat tube.

[0014] Further, the small header pipe is a round pipe or a square pipe with one end closed, one end open and a slot on the side surface.

[0015] Further, the open ends of the two small header pipes in the same heat exchanger unit, i.e. the two small header pipes connected to the same flat tube, are arranged diagonally and communicated with the large header pipe with a hole on the side surface, so as to ensure that the fluid distribution in the micro-channel of the flat tube is as uniform as possible; the small header pipes on the same side in adjacent heat exchanger units are in contact, and the open ends of the small header pipes on the same side in adjacent heat exchanger units are arranged oppositely; and the closed end of the small header pipe is closed by a plug of the small header pipe.

[0016] Further, the effective thickness of the small header pipe in the direction perpendicular to the flat tube plane is the same as the thickness of the phase change heat storage material in the direction.

[0017] Further, the phase change heat storage composite material is composed of sheet-shaped high-thermal-conductivity material and phase change material, the high-thermal-conductivity material and the phase change material are tightly packed by pressure, and the sheet layer orientation direction of the sheet-shaped high-thermal-conductivity material is consistent with the flow channel direction inside the flat tube.

[0018] Further, the mass fraction of the phase change material in the phase change heat storage composite material is 50% to 95%.

[0019] Further, the sheet-shaped high-thermal-conductivity material comprises one or more of graphite nanosheet, graphene, copper sheet, aluminum sheet, and boron nitride nanosheet; and the phase change material comprises one or more of paraffin, fatty acid, polyol, inorganic salt hydrate, inorganic salt, and water.

[0020] Further, the large header is connected to the plurality of heat exchanger units through connecting pipes, and changing the connection mode can change the maximum number of heat exchange fluid strands allowed by the compact heat storage and heat exchange device, wherein the number of large headers is twice the maximum number of heat exchange fluid strands. Taking a compact heat storage and heat exchange device comprising six heat exchanger units as an example, the connection mode can be AAAAAA (i.e., single strand of heat exchange fluid, requiring at least two large headers), ABABAB (i.e., two strands of heat exchange fluid, requiring at least four large headers), or ABCABC (i.e., three strands of heat exchange fluid, requiring at least six large headers).

[0021] Further, the maximum number of heat exchange fluid strands is determined according to specific requirements, and is suitable for single strand of heat exchange fluid, two strands of different types of heat exchange fluid, or three strands, etc.

[0022] In an embodiment of the present application, the micro-channel parallel flat tube is an aluminum flat tube, and the micro-channels inside the aluminum flat tube have micro-fins to further strengthen convective heat transfer.

[0023] In an embodiment of the present application, the small header is a square tube, and after the plurality of heat exchanger units are stacked, the small header is in close contact with no gap and forms a square cavity with the flat tube for filling the phase change heat storage material, thereby maximizing the use of space.

[0024] In an embodiment of the present application, the phase change heat storage material is a composite material of phase change material and expanded graphite, and the preparation method comprises the following steps: first, mixing expanded graphite and granular or liquid phase change material in a certain proportion (the mass fraction of the phase change material is 50% to 95%), then fully stirring under the condition that the temperature is higher than the melting point of the phase change material, and then compressing the loose composite material into the square cavity formed by the small header and the flat tube. The porosity of the composite material after compression is less than 15% (the porosity is the percentage of the volume of air in the material to the total volume of the material).

[0025] In an embodiment of the present application, after the phase change heat storage material is compressed into the heat exchanger cavity, the phase change heat storage material and the heat exchanger are integrally packaged by using potting adhesive from the outside, which can prevent leakage of the phase change material after melting and can prevent changes in contact thermal resistance caused by material shrinkage and expansion.

[0026] A second object of the present application is to provide a manufacturing method of the compact heat storage and exchange device, which comprises the following steps:

[0027] The flat tube, two small header pipes (each small header pipe has a slot hole on the side), connecting pipe and plug of the small header pipe are welded to form a heat exchanger unit, wherein the two ends of the flat tube are communicated with the slot hole on the side of the small header pipe, the connecting pipe is connected with the small header pipe, and the plug of the small header pipe is plugged into one end of the small header pipe;

[0028] A plurality of heat exchanger units are stacked and connected in a certain way by using the large header pipe with the side hole, the large header pipe is connected with the small header pipe through the connecting pipe, and each contact point or surface is fixed by using the threaded connection or welding;

[0029] The mixed powder or particles of the pre-prepared phase change material and the sheet-shaped high-thermal-conductivity material are compressed into the gap between the flat tubes, the compression direction is parallel to the flat tube plane and perpendicular to the axis of the internal flow channel of the flat tube, and the pre-prepared phase change material and the sheet-shaped high-thermal-conductivity material after compression form a phase change heat storage composite material, and finally a heat storage and exchange device with a certain flow channel is formed.

[0030] Compared with the prior art, the beneficial effects of the present application are embodied in the following aspects:

[0031] 1) The present application provides a compact heat storage and exchange device and a manufacturing method thereof, and the spatial layout of the phase change heat storage composite material microstructure and the heat exchange fluid flow channel is optimized in space, so that the high-thermal-conductivity direction of the phase change heat storage composite material is consistent with the fluid flow direction in the flat tube, and the contact thermal resistance between the phase change heat storage composite material and the flat tube is reduced through compression treatment;

[0032] 2) The present application provides a compact heat storage and exchange device and a manufacturing method thereof, and the working mode and input / output power of the heat storage and exchange device can be flexibly adjusted by changing the connection mode of the small header pipe and the large header pipe, the fluid passage can be expanded to three or more, and the heat exchange and heat storage of multiple fluid flows can be met;

[0033] 3) The present application provides a compact heat storage and exchange device and a manufacturing method thereof, and the device has simple structure, low cost and simple processing and manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a structure schematic view of the double-channel compact heat storage and exchange device (double-fluid-passage heat storage and exchange device) in Example 1.

[0035] Figure 2The schematic diagram of the manufacturing method of the double-channel compact heat storage and exchange device (double-fluid passage heat storage and exchange device) in Example 1 is shown in the figure.

[0036] Figure 3 The schematic diagram of the counter-flow (a) and co-flow (b) heat exchange between one fluid and the phase change material in the double-channel compact heat storage and exchange device (double-fluid passage heat storage and exchange device) in Example 1 is shown in the figure.

[0037] Figure 4 The schematic diagram of the counter-flow heat exchange between two fluids and the phase change material in the double-channel compact heat storage and exchange device (double-fluid passage heat storage and exchange device) in Example 1 is shown in the figure.

[0038] Figure 5 The schematic diagram of the structure of the three-fluid passage compact heat storage and exchange device (three-fluid passage heat storage and exchange device) in Example 2 is shown in the figure.

[0039] The figure shows that: 1-flat tube; 2-small header; 3-large header; 4-phase change heat storage material; 5-connection pipe. DETAILED DESCRIPTION

[0040] The patent application realizes the heat storage and exchange device with high energy density and high power density through the optimization of the heat transfer and heat storage structure. It should be pointed out that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0041] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific embodiments. The test materials used in the embodiments of the present application are all conventional test materials in the art and can be purchased through commercial channels. If the preparation means, materials, structure or composition ratio and other features are not explicitly specified in the present technical solution, they are considered as common technical features disclosed in the prior art.

[0042] The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made. These all belong to the protection scope of the present application.

[0043] The application relates to a compact heat storage and exchange device and a manufacturing method thereof, and the heat storage and exchange device comprises micro-channel parallel flow flat tubes 1, small header pipes 2, large header pipes 3 and phase change heat storage materials 4, wherein the phase change heat storage materials 4 are located between the micro-channel parallel flow flat tubes 1, the parallel flow flat tubes 1 are open at both ends and are communicated with the small header pipes 2, and the small header pipes 2 are communicated with the large header pipes 3 through connecting pipes 5; the phase change heat storage materials 4 contain heat conduction skeletons inside to form composite phase change materials, and the high-thermal-conductivity direction of the composite phase change materials is consistent with the flow channel direction in the flat tubes 1. The manufacturing method of the compact heat storage and exchange device is as follows: firstly, the parallel flow flat tubes 1 and two small header pipes 2 are assembled to form a single heat exchanger unit, then a plurality of heat exchanger units are assembled, and finally the heat exchanger units are connected through the large header pipes 3 in a certain mode to obtain a plurality of flat tube 1 heat exchangers, and then the composite phase change material particles or powder are compression-molded in the interlayer of the prefabricated flat tube 1 heat exchanger, and the compression direction is parallel to the flat tube 1 plane and perpendicular to the flat tube 1 axis. Compared with the prior art, the application optimizes the spatial layout of the phase change heat storage composite material microstructure and the heat exchange fluid flow channel in space, reduces the contact thermal resistance between the phase change heat storage composite material and the heat exchange flat tube 1, and can flexibly adjust the working mode and input / output power of the heat storage and exchange device by changing the connection mode of the small header pipes.

[0044] The application provides a compact heat storage and exchange device, which comprises:

[0045] The micro-channel parallel flow flat tube 1 comprises a plurality of parallel channels and is connected with the small header pipes 2 at both ends.

[0046] The small header pipe 2 is provided with a slot on the side surface, the parallel flow flat tube 1 is partially inserted into the slot and is welded, and the internal cross-sectional area of the small header pipe 2 is greater than or equal to the sum of the cross-sectional areas of all the flow channels in the parallel flow flat tube 1.

[0047] The large header pipe 3 is provided with a hole on the side surface and is connected with the small header pipe 2 through the connecting pipe 5.

[0048] The phase change heat storage material 4 is located between the micro-channel parallel flow flat tubes 1 and contains heat conduction skeletons inside to form composite phase change materials, and the high-thermal-conductivity direction of the composite phase change materials is consistent with the flow channel direction in the flat tubes 1.

[0049] The manufacturing method of the compact heat storage and exchange device is as follows: firstly, the parallel flow flat tubes 1 and two small header pipes 2 are assembled to form a single heat exchanger unit, then a plurality of heat exchanger units are assembled, and finally the heat exchanger units are connected through the large header pipes 3 in a certain mode to obtain a plurality of flat tube 1 heat exchangers, and then the composite phase change material particles or powder are compression-molded in the interlayer of the prefabricated flat tube 1 heat exchanger, and the compression direction is parallel to the flat tube 1 plane and perpendicular to the flat tube 1 axis.

[0050] Preferably, the micro-channel parallel flat tube 1 is an aluminum flat tube 1, the large and small header pipes 2 and the connecting pipe 5 are made of aluminum material, and the micro-channel inside the aluminum flat tube 1 has micro-fins to further strengthen the convective heat transfer. Preferably, the small header pipe 2 is a square tube, and after a plurality of heat exchanger units are stacked, the small header pipe 2 is in close contact without gaps and forms a square cavity with the flat tube 1 for filling the phase change heat storage material 4, so as to maximize the use of space.

[0051] Preferably, the phase change heat storage material 4 is a composite material of phase change material and expanded graphite, and the preparation method is as follows: first, mix the expanded graphite with the granular or liquid phase change material in a certain proportion, then fully stir and mix under the environment with a temperature higher than the melting point of the phase change material, and then compress the loose composite material into the square cavity formed by the small header pipe 2 and the flat tube 1. The phase change material used is one or more of water, paraffin, fatty acid, polyhydric alcohol, inorganic hydrated salt or inorganic salt.

[0052] Embodiment 1

[0053] As shown in Figures 1 to 2 , the embodiment provides a double-channel compact heat storage and heat exchange device, a manufacturing method and a working mode thereof. The double-channel compact heat storage and heat exchange device includes a flat tube 1 (micro-channel parallel flow flat tube), a small header pipe 2, a large header pipe 3, a phase change heat storage material 4 and a connecting pipe 5. The flat tube 1, the small header pipes 2 at both ends thereof and the connecting pipe 5 connected to the small header pipes 2 form a heat exchanger unit. Each heat exchanger unit is connected to the large header pipe 3 through the connecting pipe 5, and the phase change heat storage material 4 is filled between the heat exchanger units.

[0054] In the embodiment, the thickness of the micro-channel parallel flow flat tube can be 3-5 mm, the width can be 50-500 mm, and the number of holes / equivalent diameter of the channel can be 10-1000 μm.

[0055] The large header pipe 3 is connected to the small header pipe 2 through the connecting pipe 5 to form a fluid channel with different fluid strands. The number of the large header pipe 3 is twice the maximum allowable number of fluid strands.

[0056] For details Figure 1 , in the embodiment, the small header pipe 2 is a square tube, the side slot hole is connected to the flat tube 1, one end of the small header pipe 2 is connected to the connecting pipe 5, and the other end is sealed by a plug of the small header pipe. The open ends of the two small header pipes 2 connected to both ends of the same flat tube 1 are arranged diagonally.

[0057] For details Figure 2The manufacturing method of the double-channel compact heat storage and exchange device is as follows: ①alternately assembling heat exchanger units with connecting pipes 5, contacting the small header pipes 2 on the same side in adjacent heat exchanger units and oppositely arranging the opening ends of the small header pipes 2 on the same side in adjacent heat exchanger units, so that the spacing of the connecting pipes 5 of adjacent heat exchanger units is pulled apart; ②connecting the connecting pipes 5 of different heat exchanger units to the large header pipes 3, and for this embodiment, the opening ends of the two small header pipes 2 in the same heat exchanger unit are connected to two large header pipes 3 respectively, and since the opening ends of the small header pipes 2 on the same side in adjacent heat exchanger units are oppositely arranged, among the four large header pipes 3 in this embodiment, the two large header pipes 3 on the same side of the flat tube 1 are alternately connected to the opening ends of the small header pipes 2, that is, the small header pipes 2 of different heat exchanger units are connected, while the two large header pipes 3 on the diagonal direction of the flat tube 1 connect the small header pipes 2 of the same heat exchanger unit; ③adjusting the heat exchange device with cavities after assembly; ④adding the pre-prepared loose phase change heat storage composite material particles into the cavities and mechanically compressing to a certain density (the porosity of the composite material after compression is less than 15% (the porosity is the percentage of the volume of air in the material to the total volume of the material)), to obtain the phase change heat storage material 4; and ⑤obtaining the double-channel compact heat storage and exchange device. In step ④, after the phase change heat storage material is compressed into the heat exchanger unit cavity (the cavity here refers to the cavity formed by the flat tube 1 and the small header pipe 2 of adjacent heat exchanger units), the phase change heat storage material 4 can be integrally packaged with the heat exchanger unit by using potting glue, which can prevent the phase change material from leaking after melting, and can also prevent the contact thermal resistance from changing due to material shrinkage and expansion.

[0058] In this embodiment, the phase change heat storage material 4 is a composite material of phase change material and expanded graphite, and the ratio of the phase change material to the expanded graphite is 90:10. In this embodiment, the phase change material can be paraffin.

[0059] For details Figure 3 , the two channels in the double-channel compact heat storage and exchange device can pass the same fluid, which can flexibly exchange heat with the phase change heat storage material 4 in countercurrent Figure 3 (left a) or cocurrent Figure 3 (right b) mode.

[0060] For details Figure 4 , the two channels in the double-channel compact heat storage and exchange device pass two kinds of fluids, which can also flexibly exchange heat with the phase change heat storage material 4 in countercurrent mode.

[0061] Embodiment 2

[0062] Similar to embodiment 1, a three-fluid channel compact heat storage and exchange device as shown in Figure 5 can be manufactured, and the specific manufacturing method and fluid passage form can be referred to embodiment 1. Figure 5The heat transfer between the three fluids shown is in a co-current mode.

[0063] As Figure 5 shown, the connection, arrangement and implementation of the large header 3 in the three-fluid channel compact heat storage and heat exchange device of the present embodiment are different from those of the embodiment 1. In the present embodiment, six large headers 3 are provided. The six large headers 3 are arranged in pairs, and three pairs of large headers 3 are sequentially connected with the adjacent three heat exchanger units. In the adjacent three heat exchanger units, the open ends of the small headers 2 in the second heat exchanger unit are also closed by the plugs of the small headers, and the holes in the outer sides of the two small headers 2 (the outer side refers to the side of the small header 2 away from the flat tube 1) are connected with the two large headers 3 by the connecting pipes 5, while the open ends of the small headers 2 on the same side in the first heat exchanger unit and the third heat exchanger unit are arranged oppositely, and the two large headers 3 located on the same side of the flat tube 1 are connected with the open ends of the small headers 2 of the first heat exchanger unit and the third heat exchanger unit respectively, i.e. the small headers 2 of different heat exchanger units are connected, while the two large headers 3 located on the diagonal direction of the flat tube 1 are connected with the small headers 2 of the same heat exchanger unit.

[0064] The specific embodiments of the present application have been described above. It needs to be understood that the present application is not limited to the above description of the embodiments, which is for the convenience of the ordinary skilled person in the art to understand and use the present application. Those skilled in the art can obviously make various modifications to these embodiments, and apply the general principles described herein to other embodiments without the need for creative labor. Therefore, the present application is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present application should be within the scope of protection of the present application.

Claims

1. A compact heat storage and heat exchange device, characterized by, include: Flat tube (1), small manifold (2), large manifold (3), phase change thermal storage material (4), connecting pipe (5); The flat tube (1) is connected to the side of the small manifold (2) at both ends to form a heat exchanger unit. The small manifold (2) and the large manifold (3) are connected by a connecting pipe (5). The phase change thermal storage material (4) is located in the channel between adjacent flat tubes (1) and is in close contact with the flat tubes (1); The flat tube (1) is a microchannel parallel flow flat tube; The heat exchanger unit includes two small manifolds (2) and a flat tube (1); the two small manifolds (2) are respectively connected to both ends of the flat tube (1); The small collector tube (2) is a tube with a side slot, and the side slot is connected to the open end face of the flat tube (1); The small collector tube (2) is a round or square tube with one end closed, one end open, and a slotted hole on the side. The open ends of the two small manifolds (2) in the same heat exchanger unit are arranged diagonally and connected to the large manifold (3) with side openings to ensure uniform fluid distribution in the microchannel of the flat tube (1). The closed end of the small manifold (2) is sealed by the plug of the small manifold; The phase change thermal storage material (4) contains a thermally conductive skeleton to form a composite phase change material. The high thermal conductivity direction of the composite phase change material is consistent with the flow channel direction inside the flat tube (1). The phase change thermal storage material (4) is a composite material of phase change material and expanded graphite. The preparation method is as follows: First, expandable graphite and granular or liquid phase change material are mixed in a certain proportion. Then, the mixture is stirred evenly in an environment where the temperature is higher than the melting point of the phase change material. After that, the loose composite material is compressed into the square cavity formed by the small manifold (2) and the flat tube (1). The phase change thermal storage material (4) and the heat exchanger unit are encapsulated together using potting compound.

2. The compact heat storage and heat exchange device according to claim 1, characterized in that The phase change material includes one or more of the following: paraffin wax, fatty acids, polyols, inorganic hydrates, inorganic salts, or water.

3. The compact heat storage and heat exchange device according to claim 1, wherein The large manifold (3) is connected to multiple heat exchanger units via connecting pipes (5). The maximum allowable number of heat exchange fluid streams in the compact heat storage and heat exchange device is changed by changing the connection form between the large manifold (3) and multiple heat exchanger units. The number of large manifolds (3) is twice the maximum allowable number of heat exchange fluid streams.

4. A method of manufacturing a compact heat storage heat exchanger according to any one of claims 1 to 3, characterized by, The manufacturing method includes the following steps: S1. First, weld the flat tube (1) to two small manifolds (2), and then connect it to the connecting pipe (5) and the plug of the small manifolds by thread or welding to form a heat exchanger unit. The flat tube (1) is connected to the side of the small manifolds (2) at both ends, the connecting pipe (5) is connected to one end of the small manifolds (2), and the other end of the small manifolds (2) is sealed with a plug. S2. Stack multiple heat exchanger units and connect them with a large manifold (3) with side openings. The large manifold (3) is connected to the connecting pipe (5), and each contact point or surface is fixed by threaded connection or welding. S3, the pre-prepared phase change material and the mixed powder or particle of expanded graphite are compressed into the gap between the flat tubes (1), the compression direction is parallel to the plane of the flat tubes (1) and perpendicular to the axis of the internal flow channel of the flat tubes (1), and the pre-prepared phase change material and the mixed powder or particle of expanded graphite after compression form the phase change heat storage material (4), and finally the heat storage and heat exchange device with a certain flow channel is formed.

5. The method of claim 4, wherein the compact heat storage and heat exchange device is manufactured by the steps of: In step S3, the pre-prepared phase change material and the mixed powder or particle of expanded graphite are compressed into the gap between the flat tubes (1), and the porosity of the phase change heat storage material (4) after compression is less than 15%.

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