Heat exchange core, heat exchanger and fresh air machine

Abstract

This utility model relates to the technical field of heat exchange equipment, and discloses a heat exchange core, a heat exchanger, and a fresh air unit. The heat exchange core comprises multiple silicon carbide ceramic units; these units are periodically arranged to form the heat exchange core; the cross-section of each silicon carbide ceramic unit is hexagonal; and each silicon carbide ceramic unit has flow channels along its axial direction. The hexagonal structure of the silicon carbide ceramic units allows for a honeycomb-like dense arrangement, forming more flow channels per unit volume, thereby significantly increasing the contact area between hot and cold fluids and enhancing heat transfer. The periodic structure ensures uniform heat distribution throughout the entire heat exchange core. In summary, the heat exchange core comprehensively improves heat exchange efficiency through the high thermal conductivity of silicon carbide ceramics, the high specific surface area of ​​the hexagonal densely packed structure, the low resistance and high efficiency heat transfer of the axial flow channels, and the optimized thermal field of the periodic arrangement, thus solving the problem of insufficient heat exchange efficiency in existing heat exchange cores.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange equipment technology, and in particular to a heat exchange core, heat exchanger and fresh air unit. Background Technology

[0002] Heat exchange cores are not only the core component of fresh air systems, but also the core component of many heat exchangers. Currently, heat exchange cores can be classified according to their material into metal heat exchange cores, plastic heat exchange cores, and ceramic heat exchange cores. However, the heat exchange efficiency of existing heat exchange cores typically only reaches a maximum of 90%, so optimizing the heat exchange efficiency of heat exchange cores has always been a goal pursued by the industry. Utility Model Content

[0003] This utility model provides a heat exchange core, a heat exchanger, and a fresh air unit to solve the problem that the heat exchange efficiency of existing heat exchange cores needs to be improved.

[0004] The first aspect of this utility model provides a heat exchange core, comprising:

[0005] Multiple silicon carbide ceramic units are periodically arranged to form the heat exchange core; the cross-section of each silicon carbide ceramic unit is hexagonal; and each silicon carbide ceramic unit has a flow channel along its own axial direction.

[0006] According to the heat exchange core provided by this utility model, one end of the flow channel is an air inlet and the other end is an air outlet; the diameter of the air inlet is larger than the diameter of the air outlet.

[0007] According to the heat exchange core provided by this utility model, the aperture of the flow channel gradually decreases along the direction from the air inlet to the air outlet.

[0008] According to the heat exchange core provided by this utility model, the ratio of the diameter of the air inlet to the diameter of the air outlet is (1~3):(0.5~1.5).

[0009] According to the heat exchange core provided by this utility model, the ratio of the diameter of the air inlet to the diameter of the air outlet is 2:1.

[0010] According to the heat exchange core provided by this utility model, the flow channel is spiral-shaped.

[0011] According to the heat exchange core provided by this utility model, the silicon carbide ceramic unit has a porous structure with a porosity of 40% to 60%.

[0012] According to the heat exchange core provided by this utility model, the pore size of the micropores in the silicon carbide ceramic unit is 0.1mm~1mm.

[0013] The second aspect of this utility model provides a heat exchanger, including the heat exchange core described in any of the above claims.

[0014] The third aspect of this utility model provides a fresh air blower, which includes the heat exchange core described in any of the above claims, or includes the heat exchanger described in the above claims.

[0015] The heat exchange core provided by this invention utilizes silicon carbide ceramic, whose thermal conductivity is significantly higher than that of traditional metals (such as stainless steel) or plastics. This allows for rapid heat transfer, reduced thermal resistance, and thus improved heat exchange rates between hot and cold fluids. Silicon carbide exhibits stable performance in high-temperature and corrosive environments, preventing efficiency degradation caused by material degradation. The high mechanical strength of silicon carbide ceramics allows for thinner channel wall designs, further reducing thermal resistance. The hexagonal structure of the silicon carbide ceramic units enables honeycomb-like close packing, forming more channels per unit volume, significantly increasing the contact area between hot and cold fluids and enhancing heat transfer. The periodic structure ensures uniform heat distribution throughout the heat exchange core, preventing localized overheating or undercooling and fully utilizing all heat exchange units. The periodic structure design allows for flexible expansion of the heat exchange area as needed without altering the individual point heat transfer efficiency. In summary, the heat exchange core of this embodiment comprehensively improves heat exchange efficiency through the high thermal conductivity of silicon carbide ceramic, the high specific surface area of ​​the hexagonal close-packed structure, the low resistance and high efficiency of axial flow channels, and the optimized thermal field of periodic arrangement, thus solving the problem of insufficient heat exchange efficiency in existing heat exchange cores. Furthermore, combined with fresh air unit testing, the heat exchange efficiency of the heat exchange core of this embodiment reaches 95% under the same airflow, which is 5 percentage points higher than that of existing heat exchange cores. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is one of the structural schematic diagrams of the silicon carbide ceramic unit of the heat exchange core provided by this utility model.

[0018] Figure 2 This is the second schematic diagram of the silicon carbide ceramic unit of the heat exchange core provided by this utility model.

[0019] Figure 3 This is the third schematic diagram of the silicon carbide ceramic unit of the heat exchange core provided by this utility model.

[0020] Figure 4 yes Figure 3 A schematic diagram of the structure of section AA.

[0021] Figure 5 This is the fourth schematic diagram of the silicon carbide ceramic unit of the heat exchange core provided by this utility model.

[0022] Figure 6 This is a schematic diagram of the structure of the heat exchange core provided by this utility model. The flow channel is not shown in the figure.

[0023] Figure label:

[0024] 110. Silicon carbide ceramic unit; 101. Flow channel; 102. Air inlet; 103. Air outlet. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model based on the specific circumstances.

[0028] In this embodiment of the utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] In embodiments of this utility model, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0031] The following is combined Figures 1 to 6 The structure of the heat exchange core provided by this utility model is described in detail.

[0032] like Figures 1 to 6 As shown, a specific embodiment of the first aspect of this utility model provides a heat exchange core. The heat exchange core includes a plurality of silicon carbide ceramic units 110; the plurality of silicon carbide ceramic units 110 are periodically arranged to form a heat exchange core; the cross-section of the silicon carbide ceramic unit 110 is hexagonal; and the silicon carbide ceramic unit 110 has a flow channel 101 along its own axial direction.

[0033] In this embodiment, silicon carbide ceramics have a much higher thermal conductivity than traditional metals (such as stainless steel) or plastics, enabling rapid heat transfer, reducing thermal resistance, and thus improving the heat exchange rate between hot and cold fluids. Silicon carbide exhibits stable performance in high-temperature and corrosive environments, avoiding efficiency degradation caused by material degradation. The high mechanical strength of silicon carbide ceramics allows for thinner flow channel 101 wall thicknesses, further reducing thermal resistance. The hexagonal structure of the silicon carbide ceramic units 110 allows for honeycomb-like close packing, forming more flow channels 101 per unit volume, significantly increasing the contact area between the fluid (e.g., air or liquid) and the silicon carbide ceramic units, enhancing heat transfer. The periodic structure ensures uniform heat distribution throughout the overall heat exchange core, preventing localized overheating or undercooling and fully utilizing all heat exchange units. The periodic structure design allows for flexible expansion of the heat exchange area as needed without altering the single-point heat transfer efficiency. In summary, the heat exchange core of this embodiment comprehensively improves heat exchange efficiency through the high thermal conductivity of silicon carbide ceramic, the high specific surface area of ​​the hexagonal close-packed structure, the low resistance and high efficiency heat transfer of the axial flow channel 101, and the optimized thermal field of the periodic arrangement, thus solving the problem of insufficient heat exchange efficiency in existing heat exchange cores. Furthermore, combined with fresh air unit testing, the heat exchange efficiency of the heat exchange core of this embodiment reaches 95% under the same air volume, which is 5 percentage points higher than that of existing heat exchange cores.

[0034] like Figures 1 to 4 As shown, in some embodiments, the flow channel 101 is helical. The helical flow channel 101 significantly extends the flow path of fluids (e.g., air or liquid) within the silicon carbide ceramic unit 110, allowing more time for heat transfer between hot and cold fluids, thereby improving the adequacy of heat exchange. The hot and cold fluids in the helical flow channel 101 are subjected to centrifugal force, generating secondary flow, disrupting the laminar boundary layer, and reducing thermal resistance. The fluid rotation caused by the helical structure promotes radial mixing of hot and cold fluids, resulting in a more uniform temperature distribution and improved heat transfer efficiency. The helical flow channel 101 achieves a longer heat transfer path within a limited space, making it more compact than a straight axial flow channel 101. The rotational motion of the fluid in the helical flow channel 101 reduces particulate matter deposition on the wall surface, delaying fouling formation and maintaining high-efficiency heat transfer over a long period. The high strength of silicon carbide ceramic allows the helical flow channel 101 to achieve a smaller radius of curvature, further increasing the density of the flow channel 101 without cracking.

[0035] like Figure 5 As shown, in some other embodiments, the silicon carbide ceramic unit 110 has two flow channels 101 formed along its own axial direction. The two flow channels 101 are arranged side by side and partially overlap to form a flow channel with a figure-eight cross-section. Compared with a single flow channel, this can further improve heat exchange efficiency. The narrow connection in the middle of the figure-eight shape forces the fluid to accelerate as it passes through, generating local eddies, disrupting the thermal boundary layer, and reducing thermal resistance.

[0036] In some embodiments, one end of the flow channel 101 is an air inlet 102 and the other end is an air outlet 103; the diameter of the air inlet 102 is larger than the diameter of the air outlet 103.

[0037] In this embodiment, the large-aperture air inlet 102 can reduce the initial flow velocity of the fluid, prolong the residence time of the fluid in the flow channel 101, ensure that heat (or cold) can be fully stored, and also reduce inlet pressure loss. The small-aperture air outlet 103 accelerates the fluid by reducing the cross-sectional area, which can enhance flow interruption, thin the thermal resistance boundary layer, improve the heat transfer coefficient, improve heat exchange efficiency, and also prevent the deposition of particulate matter in the fluid.

[0038] Optionally, the aperture of the flow channel 101 gradually decreases along the direction from the air inlet 102 to the air outlet 103. The tapered structure converts air pressure energy into kinetic energy, and the high-speed air at the outlet can naturally draw in surrounding air, which can flush the walls of the flow channel 101 and reduce particle deposition. Through pressure-to-kinetic energy conversion, the tapered flow channel 101 reduces the external power required by the system, thereby reducing the fan power.

[0039] Optionally, the ratio D of the aperture D1 of the air inlet 102 to the aperture D2 of the air outlet 103 is (1~3):(0.5~1.5). By precisely controlling the contraction ratio of the cross-section of the flow channel 101, an optimal balance can be achieved between aerodynamic performance, heat exchange efficiency, and system reliability. This can improve heat exchange efficiency, ensure the mechanical strength of the equipment, and reduce the risk of breakage of the silicon carbide ceramic unit.

[0040] Optionally, the ratio D of the aperture D1 of the air inlet 102 to the aperture D2 of the air outlet 103 is 2:1. This can increase the Reynolds number of the air, thereby significantly improving heat exchange efficiency and reducing the power consumption of the fan.

[0041] For example, the diameter D1 of the air inlet 102 is 0.67 mm, and the diameter D2 of the air outlet 103 is 0.33 mm.

[0042] In some embodiments, the silicon carbide ceramic unit 110 has a porous structure with a porosity of 40% to 60%. The porous structure allows air to flow within the flow channel 101, creating microscale turbulence through the pores, increasing the effective heat transfer area by 3 to 5 times compared to a dense structure. The macroscopic flow channel 101 handles the main flow, while the micropores of the porous structure enhance local disturbances, achieving a two-stage heat exchange between the macroscopic and microscopic levels. The porosity of 40% to 60% also reduces the amount of silicon carbide used, lowering material costs.

[0043] It should be noted that porosity is the volume percentage of micropores in silicon carbide ceramics.

[0044] Optionally, the pore size of the silicon carbide ceramic unit 110 is 0.1mm to 1mm. This increases the heat exchange area while ensuring airflow, and it is less prone to clogging and easier to clean. In summary, by controlling the pore size of the silicon carbide ceramic unit 110 within the range of 0.1mm to 1mm, combined with a porosity design of 40% to 60%, the performance of the heat exchange core can be further optimized at the microscale.

[0045] In some embodiments, the surface of the silicon carbide ceramic unit 110 is covered with an antioxidant coating. The antioxidant coating can improve the service life of the silicon carbide ceramic unit 110.

[0046] Optionally, the antioxidant coating is a mixture of silica and alumina.

[0047] like Figure 6 As shown, in some embodiments, the heat exchange core is a cylinder. The cylindrical structure avoids flow stagnation in right-angle or sharp-corner areas, ensuring uniform air distribution along the circumference and reducing localized thermal stress and fouling. When subjected to internal pressure, the cylinder exhibits uniform circumferential and axial stress distribution with no stress concentration points, thus improving the mechanical strength of the heat exchange core.

[0048] It is understandable that heat exchange cores can be molded as a single piece. For example, heat exchange cores can be prepared by sintering.

[0049] For example, based on the structure of the heat exchange core, engineering drawings are created and a 3D model is constructed. Silicon carbide powder is mixed with graphene spheroids to obtain a mixture, wherein the weight percentage of graphene is approximately 5%. The 3D model is input into an additive manufacturing equipment, the mixture is loaded into the hopper of the additive manufacturing equipment, and a silicon carbide ceramic green body is manufactured using additive manufacturing technology. Next, after cleaning the green body, it is pretreated using baking and pre-firing processes to obtain a pre-fired body. Finally, the pre-fired body is placed in a vacuum furnace or atmosphere furnace and sintered at high temperature to obtain the heat exchange core.

[0050] A specific embodiment of the second aspect of this utility model provides a heat exchanger. This heat exchanger includes the heat exchange core of any of the above embodiments.

[0051] In this embodiment, since it includes the heat exchange core of any of the above embodiments, it has at least the above advantages, which will not be repeated here.

[0052] In some embodiments, the heat exchanger includes a housing; a heat exchange core is mounted within the housing. The housing serves to protect the heat exchange core.

[0053] A specific embodiment of the third aspect of this utility model provides a fresh air fan. This fresh air fan includes the heat exchange core of any of the above embodiments, or includes the heat exchanger of any of the above embodiments.

[0054] In this embodiment, since it includes the heat exchange core of any of the above embodiments, it has at least the above advantages, which will not be repeated here.

[0055] In some embodiments, the fresh air unit further includes a fan module; the fan module is disposed on the air inlet side and / or air outlet side of the heat exchange core to provide power for airflow.

[0056] Optionally, the fan module includes a first fan; the first fan is located on the air inlet side of the heat exchange core; the first fan can rotate in either the forward or reverse direction. When rotating in the forward direction, the first fan is used to introduce fresh outdoor air into the room; when rotating in the reverse direction, the first fan is used to draw indoor air to the outside.

[0057] Optionally, the fan module includes an exhaust fan and a ventilation fan; the exhaust fan and ventilation fan are respectively installed on the air inlet side and air outlet side of the heat exchange core. When the exhaust fan rotates in the forward direction and the ventilation fan is stopped, it can introduce fresh air into the room. When the ventilation fan rotates in the forward direction and the exhaust fan is stopped, it can exhaust indoor air to the outside.

[0058] In some embodiments, the fresh air unit further includes an environmental parameter detection module and a control module; the control module is electrically connected to both the environmental parameter detection module and the fan module. The environmental parameter detection module is used to detect environmental parameters of the air, including but not limited to at least one or a combination of air temperature, air humidity, and carbon dioxide concentration. The control module outputs control commands based on the environmental parameters to control the operating state of the fan module; the fan module has a first operating state and a second operating state; in the first operating state, the fan module is used to introduce outdoor fresh air into the room; in the second operating state, the fan module is used to exhaust indoor air to the outside.

[0059] It is understood that in some embodiments, the first operating state is that the first fan rotates in the forward direction, and the second operating state is that the first fan rotates in the reverse direction. In other embodiments, the first operating state is that the exhaust fan rotates in the forward direction and the exhaust fan is stopped; the second operating state is that the exhaust fan rotates in the forward direction and the exhaust fan is stopped.

[0060] Optionally, the environmental parameter detection module includes at least one or a combination of several of a temperature detection unit, a humidity detection unit, or a carbon dioxide detection unit. The environmental parameter detection module is located on the outlet side of the heat exchanger.

[0061] Optionally, a temperature detection unit is used to detect the temperature of the fresh air and the indoor temperature. A humidity detection unit is used to detect the humidity of the fresh air and the indoor humidity. A carbon dioxide detection unit is used to detect the carbon dioxide concentration in the fresh air and the indoor carbon dioxide concentration.

[0062] Optionally, the control module can determine the enthalpy of fresh air based on the built-in enthalpy calculation formula, combined with the obtained fresh air temperature and humidity; and determine the enthalpy of fresh air based on the indoor temperature and humidity; then, the control module is also used to control the operating status of the fan module based on the enthalpy difference between the fresh air enthalpy and the indoor enthalpy, so that the enthalpy difference is within the enthalpy difference threshold range.

[0063] It should be noted that the formula for calculating enthalpy is existing technology and will not be elaborated here.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A heat exchange core, characterized in that, include: Multiple silicon carbide ceramic units (110) are periodically arranged to form the heat exchange core; The cross-section of the silicon carbide ceramic unit (110) is hexagonal; the silicon carbide ceramic unit (110) has a flow channel (101) along its own axial direction.

2. The heat exchange core according to claim 1, characterized in that, One end of the flow channel (101) is an air inlet (102), and the other end is an air outlet (103); the diameter of the air inlet (102) is larger than the diameter of the air outlet (103).

3. The heat exchange core according to claim 2, characterized in that, Along the direction from the air inlet (102) to the air outlet (103), the aperture of the flow channel (101) gradually decreases.

4. The heat exchange core according to claim 2, characterized in that, The ratio of the diameter of the air inlet (102) to the diameter of the air outlet (103) is (1~3):(0.5~1.5).

5. The heat exchange core according to claim 2, characterized in that, The ratio of the diameter of the air inlet (102) to the diameter of the air outlet (103) is 2:

1.

6. The heat exchange core according to claim 1, characterized in that, The flow channel (101) is spiral-shaped.

7. The heat exchange core according to any one of claims 1 to 6, characterized in that, The silicon carbide ceramic unit (110) has a porous structure with a porosity of 40% to 60%.

8. The heat exchange core according to claim 7, characterized in that, The pore size of the micropores in the silicon carbide ceramic unit (110) is 0.1 mm to 1 mm.

9. A heat exchanger, characterized in that, Includes the heat exchange core as described in any one of claims 1 to 8.

10. A fresh air ventilator, characterized in that, It includes the heat exchange core as described in any one of claims 1 to 8, or the heat exchanger as described in claim 9.

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