A printed circuit board type heat exchanger core, heat exchanger and supercritical carbon dioxide Brayton cycle system

Abstract

This application relates to the field of heat exchange devices, providing a printed circuit board type heat exchanger core, a heat exchanger, and a supercritical carbon dioxide Brayton cycle system. The core includes a first plate and a second plate arranged alternately in sequence. The two sides of the first plate are A-side and B-side, and the two sides of the second plate are C-side and D-side. For adjacent first and second plates, A-side and D-side are adjacent, and B-side and C-side are adjacent. A-side is etched with a first microchannel. C-side includes a cooling zone, a partition zone, and a regenerating zone, which are distributed sequentially along the length of C-side. The cooling zone is etched with a second microchannel, and the regenerating zone is etched with a third microchannel. This application integrates the functions of a cooler and a regenerator into the same heat exchanger core, achieving a compact structure, reducing system volume and flow resistance, reducing heat loss, improving system efficiency, and simultaneously reducing equipment and maintenance costs.

Description

Technical Field

[0001] This application relates to the field of heat exchange device technology, and in particular to a printed circuit board type heat exchanger core, heat exchanger and supercritical carbon dioxide Brayton cycle system. Background Technology

[0002] Supercritical carbon dioxide (sCO2) Brayton cycle systems are power systems based on closed-loop Brayton cycle power generation technology that convert various forms of energy into electricity by configuring different heat sources. As a disruptive energy conversion solution, it is becoming a focal point of global energy technology competition.

[0003] Currently, power generation systems based on supercritical carbon dioxide Brayton cycles encompass heaters, regenerators, coolers, compressors, turbine generators, and associated piping and valves. The energy conversion cycle of this power generation system operates as follows: Compressed supercritical carbon dioxide (SCO2) (cold-side SCO2) enters the regenerator, where it is heated by high-temperature SCO2 exhaust gas from the turbine (hot-side SCO2). It then enters the heater for further heating to the designed maximum cycle temperature. The high-temperature, high-pressure SCO2 expands and performs work in the turbine, and the generator converts mechanical energy into electrical energy. The high-temperature SCO2 exhaust gas (hot-side SCO2) then enters the regenerator, where it is cooled by high-pressure, low-temperature SCO2 from the compressor (cold-side SCO2). After further cooling to near the critical temperature by the cooler, it re-enters the compressor, completing one cycle.

[0004] In this power generation system, the regenerator and cooler are key heat exchange devices, responsible for heat recovery and carbon dioxide cooling, respectively. In existing power generation systems, the regenerator and cooler are typically installed independently. However, this independent installation presents several problems. First, the independent equipment occupies a large space, increasing the overall system size and installation difficulty, which is detrimental to a compact system design. Second, the numerous connecting pipes between the independent equipment not only increase the system's flow resistance but also lead to increased heat loss, reducing the overall system efficiency. Furthermore, the use of multiple independent devices significantly increases equipment and maintenance costs. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a printed circuit board type heat exchanger core, a heat exchanger, and a supercritical carbon dioxide Brayton cycle system. This application integrates the functions of a cooler and a regenerator into a single heat exchanger core, achieving a compact structure, reducing system volume and flow resistance, decreasing heat loss, and improving system efficiency. Simultaneously, it reduces equipment and maintenance costs. The technical solution adopted in this application is as follows: A printed circuit board type heat exchanger core for a supercritical carbon dioxide Brayton cycle system includes a plurality of first plates and a plurality of second plates arranged alternately in sequence; the two sides of the first plates are A-side and B-side, and the two sides of the second plates are C-side and D-side; for adjacent first plates and second plates, the A-side and D-side are adjacent, and the B-side and C-side are adjacent; the A-side is etched with a first microchannel for hot-side CO2 flow; the C-side includes a cooling zone, a partition zone, and a regenerating zone, which are distributed sequentially along the length of the C-side; the cooling zone is etched with a second microchannel for cooling water flow, the regenerating zone is etched with a third microchannel for cold-side CO2 flow, and the partition zone is not etched with microchannels; in operation, the hot CO2 flowing through the first microchannel exchanges heat with the cold-side CO2 flowing through the third microchannel and the cooling water flowing through the second microchannel.

[0006] By simultaneously incorporating a first microchannel for hot-side SO2 flow, a second microchannel for cooling water flow, and a third microchannel for cold-side SO2 flow within the core, the cooler and regenerator functions are integrated into a single heat exchanger core. Compared to existing technologies where the cooler and regenerator are separately installed, this significantly reduces the equipment's footprint and volume, resulting in a more compact structure for the supercritical CO2 Brayton cycle power generation system, facilitating layout and installation. Simultaneously, it reduces the number of connecting pipes between independent devices (cooler and regenerator), lowering system flow resistance and heat loss during pipe transport, thus improving the overall efficiency of the power generation system. Furthermore, the integration of cooler and regenerator functions reduces the number of devices, lowering manufacturing, installation, and maintenance costs, resulting in excellent economic efficiency.

[0007] In some embodiments, the D-plate surface is etched with a fourth microchannel corresponding to the first microchannel on the A-plate surface, and the first microchannel and the fourth microchannel are aligned along the core thickness direction to form a microchannel for hot-side CO2 flow.

[0008] By etching a fourth microchannel on the D-plate surface, the cross-sectional area of ​​the microchannel used for hot-side CO2 flow is increased. In other words, the heat transfer area for heat exchange is increased, which facilitates heat exchange between the hot-side CO2 and the cold-side CO2 and cooling water, thereby improving heat exchange efficiency. From another perspective, it also helps to reduce the volume of the heat exchanger core.

[0009] In some embodiments, the B-side is etched with a fifth microchannel corresponding to the second microchannel on the C-side, and the second microchannel and the fifth microchannel are aligned along the core thickness direction to form a microchannel for cooling water flow.

[0010] By etching a fifth microchannel on the B-side plate, the cross-sectional area of ​​the microchannels used for cooling water flow is increased. In other words, the heat transfer area for heat exchange is increased, which facilitates heat exchange between the cooling water and the hot-side CO2, thus improving heat exchange efficiency. From another perspective, this also helps to reduce the volume of the heat exchanger core.

[0011] In some embodiments, the B-side is etched with a sixth microchannel corresponding to the third microchannel on the C-side, and the third microchannel and the sixth microchannel are aligned along the core thickness direction to form a microchannel for cold-side CO2 flow.

[0012] By etching a sixth microchannel on the B-plate, the cross-sectional area of ​​the microchannel used for cold-side CO2 flow is increased. In other words, the heat transfer area for heat exchange is increased, which facilitates heat exchange between cold-side and hot-side CO2 and improves heat exchange efficiency. From another perspective, it also helps to reduce the volume of the heat exchanger core.

[0013] In some embodiments, the first microchannel is a straight-through structure that is parallel to the length direction of the first plate, and the inlet and outlet of the first microchannel are respectively located on both sides of the length direction of the first plate.

[0014] By setting the first microchannel as a straight-through structure, the structure is simple and the flow resistance is small, which can avoid pressure loss when hot-side sCO2 flows in the first microchannel.

[0015] In some embodiments, the second microchannel is a Z-shaped baffle structure, with its inlet and outlet located on opposite sides of the width of the second plate; the inlet of the second microchannel is closer to the outlet of the first microchannel than its outlet; the third microchannel is a Z-shaped baffle structure, with its inlet and outlet located on opposite sides of the width of the second plate; the outlet of the third microchannel is closer to the inlet of the first microchannel than its inlet.

[0016] By configuring both the second and third microchannels as Z-shaped baffle structures, with the inlet and outlet of the second and third microchannels located on opposite sides of the width of the second plate, and by placing the inlet of the second microchannel closer to the outlet of the first microchannel than the outlet of the second microchannel, and the outlet of the third microchannel closer to the inlet of the first microchannel than the inlet of the third microchannel, this arrangement of the second and first microchannels forms an orthogonal counter-current flow configuration. This maximizes the heat exchange temperature difference, prevents temperature pinch points, and ensures heat exchange efficiency. Similarly, the arrangement of the third microchannel, together with the arrangement of the first microchannel, forms an orthogonal counter-current flow configuration, maximizing the heat exchange temperature difference, preventing temperature pinch points, and also ensuring heat exchange efficiency.

[0017] In some embodiments, the cross-section of the third microchannel gradually increases from its inlet to its outlet along the layout direction of the third microchannel.

[0018] By setting the third microchannel to a variable cross-section, the flow resistance of the cold-side SCO2 can be reduced while enhancing the heat exchange between the cold-side and hot-side SCO2, thereby further improving the overall system efficiency.

[0019] In some embodiments, the cross-sectional shape of the first microchannel is any one of a semi-circular, semi-elliptical, U-shaped, rectangular, or trapezoidal shape; the cross-sectional shape of the second microchannel is any one of a semi-circular, semi-elliptical, U-shaped, rectangular, or trapezoidal shape; and the cross-sectional shape of the third microchannel is any one of a semi-circular, semi-elliptical, U-shaped, rectangular, or trapezoidal shape.

[0020] On the other hand, this application provides a heat exchanger for a supercritical carbon dioxide Brayton cycle system, including the aforementioned printed circuit board type heat exchanger core.

[0021] This application also provides a supercritical carbon dioxide Brayton cycle system, which employs the aforementioned heat exchanger.

[0022] The printed circuit board type heat exchanger core, heat exchanger, and supercritical carbon dioxide Brayton cycle system provided in this application have at least one of the following beneficial effects: 1. This application provides a printed circuit board type heat exchanger core, which integrates the functions of a cooler and a regenerator into a single core by simultaneously setting a first microchannel for hot-side SO2 flow, a second microchannel for cooling water flow, and a third microchannel for cold-side SO2 flow. Compared to the prior art where the cooler and regenerator are set up separately, this significantly reduces the equipment's footprint and volume, making the structure of the supercritical carbon dioxide Brayton cycle power generation system more compact and easier to arrange and install. Simultaneously, it reduces the connecting pipes between independent devices (cooler and regenerator), lowers the system's flow resistance, reduces heat loss during pipe transmission, and improves the overall efficiency of the power generation system. Furthermore, the integration of cooler and regenerator functions reduces the number of devices, lowering manufacturing, installation, and maintenance costs, resulting in excellent economic efficiency.

[0023] 2. The printed circuit board heat exchanger core provided in this application increases the cross-sectional area of ​​the microchannels used for hot-side CO2 flow by etching a fourth microchannel on the D-side of the board. In other words, it increases the heat transfer area for heat exchange, which facilitates heat exchange between the hot-side CO2 and the cold-side CO2 and cooling water, thereby improving heat exchange efficiency. From another perspective, it also helps to reduce the volume of the heat exchanger core.

[0024] 3. The printed circuit board heat exchanger core provided in this application increases the cross-sectional area of ​​the microchannels used for cooling water flow by etching a fifth microchannel on the B-side of the board. In other words, it increases the heat transfer area for heat exchange, which is beneficial for heat exchange between cooling water and hot-side CO2, thus improving heat exchange efficiency. From another perspective, it is also beneficial for reducing the volume of the heat exchanger core.

[0025] 4. The printed circuit board heat exchanger core provided in this application increases the cross-sectional area of ​​the microchannel used for cold-side CO2 flow by etching a sixth microchannel on the B-side of the plate. In other words, it increases the heat transfer area for heat exchange, which is beneficial for heat exchange between cold-side and hot-side CO2 and improves heat exchange efficiency. From another perspective, it is also beneficial to reduce the volume of the heat exchanger core.

[0026] 5. The printed circuit board heat exchanger core provided in this application has a simple structure and low flow resistance by setting the first microchannel as a straight-through structure, which can avoid pressure loss when hot-side sCO2 flows in the first microchannel.

[0027] 6. The printed circuit board heat exchanger core provided in this application is configured with both the second and third microchannels as Z-shaped baffle structures, with the inlet and outlet of the second and third microchannels respectively located on opposite sides of the width of the second plate. Furthermore, the inlet of the second microchannel is closer to the outlet of the first microchannel than its outlet; similarly, the outlet of the third microchannel is closer to the inlet of the first microchannel than its inlet. This arrangement of the second and first microchannels forms an orthogonal counter-current flow configuration, maximizing the heat exchange temperature difference, preventing temperature pinch points, and ensuring heat exchange efficiency. Similarly, the arrangement of the third and first microchannels also forms an orthogonal counter-current flow configuration, maximizing the heat exchange temperature difference, preventing temperature pinch points, and ensuring heat exchange efficiency.

[0028] 7. The printed circuit board heat exchanger core provided in this application can reduce the flow resistance of cold-side sCO2 by setting the third microchannel in a variable cross-section form, thereby enhancing the heat exchange between cold-side sCO2 and hot-side sCO2 and further improving the overall system efficiency. Attached Figure Description

[0029] The preferred embodiments will be described below in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of a printed circuit board heat exchanger core, heat exchanger, and supercritical carbon dioxide Brayton cycle system: Figure 1 This is a schematic diagram of the internal flow pattern of the heat exchanger using the core of this application, where the red dashed line represents the first microchannel, the green dashed line represents the second microchannel, and the blue dashed line represents the third microchannel; Figure 2 This is a schematic diagram of the structure of one embodiment of the core of this application; Figure 3 This is a schematic diagram of the structure of the second plate in the core of this application; Figure 4 This is a schematic diagram of the structure of an embodiment of the first plate in the core of this application.

[0030] Explanation of icon numbers: The printed circuit board type heat exchanger core 1 includes a first plate 11, an A plate surface 111, a first microchannel 1111, a B plate surface 112, a second plate 12, a C plate surface 121, a cooling zone 1211, a second microchannel 12111, a separation zone 1212, a regeneration zone 1213, a third microchannel 12131, and a D plate surface 122. Detailed Implementation

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0032] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0033] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0034] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] Printed circuit heat exchangers (PCHEs), as a new type of heat exchanger, have advantages such as compact structure, high efficiency, and high pressure resistance. Due to their excellent thermo-hydraulic characteristics, PCHEs are widely used in supercritical fluids. The core of the PCHE is its core component, which is assembled by diffusion welding of stacked metal plates etched with medium flow channels. Through these processing techniques, PCHEs can operate in extreme environments (temperatures above 900℃ and pressures above 60MPa).

[0037] Currently, supercritical carbon dioxide Brayton cycles commonly employ printed circuit board heat exchangers (PCHEs) to ensure their compactness advantage compared to other energy conversion cycles. PCHEs were first researched and manufactured by Heatric in the UK, a company that still holds a dominant position in the industry. Compared to traditional shell-and-tube heat exchangers, PCHEs can reduce volume by approximately 85% for the same heat exchange capacity. Because the core of a PCHE can be considered a single, integral structure, it offers significant advantages under high-temperature and high-pressure environments. Supercritical carbon dioxide Brayton cycles can operate at pressures exceeding 20 MPa and temperatures exceeding 500°C; therefore, PCHEs are widely used to ensure both compactness and safety.

[0038] Currently, PCHE is widely used as a regenerator and cooler in sCO2 Brayton cycle systems. However, in these systems, the regenerator and cooler are used as two separate devices, which leads to the problems mentioned in the background section, which will not be elaborated here.

[0039] To resolve the aforementioned technical issues, refer to Figures 1-4 This application provides a printed circuit board type heat exchanger core for a supercritical carbon dioxide Brayton cycle system. The printed circuit board type heat exchanger core 1 includes a plurality of first plates 11 and a plurality of second plates 12 arranged alternately in sequence. The two sides of the first plates 11 are A plate surface 111 and B plate surface 112, respectively, and the two sides of the second plates 12 are C plate surface 121 and D plate surface 122, respectively. For adjacent first plates 11 and second plates 12, A plate surface 111 and D plate surface 122 are adjacent, and B plate surface 112 and C plate surface 121 are adjacent. A plate surface 111 is etched with a first microchannel 1111, which is used for hot-side CO2 flow. C plate surface 121 is covered with... The system includes a cooling zone 1211, a partition zone 1212, and a regenerating zone 1213, which are sequentially distributed along the length of the C-plate surface 121. The cooling zone 1211 is etched with a second microchannel 12111 for cooling water flow. The regenerating zone 1213 is etched with a third microchannel 12131 for cold-side CO2 flow. The partition zone 1212 is not etched with microchannels. In operation, the hot CO2 flowing through the first microchannel 12111 exchanges heat with the cold-side CO2 flowing through the third microchannel 12131 and the cooling water flowing through the second microchannel 12111.

[0040] In this embodiment, the partition 1212 acts as a barrier to prevent cross-flow between cooling water and cold-side SO2. It is understood that by simultaneously providing a first microchannel 1111 for hot-side SO2 flow, a second microchannel 12111 for cooling water flow, and a third microchannel 12131 for cold-side SO2 flow in the printed circuit board heat exchanger core 1, the cooler and regenerator functions are integrated into the same heat exchanger core. Compared to the prior art where the cooler and regenerator are set up separately, this significantly reduces the equipment's footprint and volume, making the supercritical carbon dioxide Brayton cycle power generation system more compact and easier to arrange and install. Simultaneously, it reduces the connecting pipes between independent devices (cooler and regenerator), lowers the system's flow resistance, reduces heat loss during pipe transmission, and improves the overall efficiency of the power generation system. Furthermore, integrating the cooler and regenerator functions reduces the number of devices, lowers manufacturing, installation, and maintenance costs, and offers good economic efficiency.

[0041] In one embodiment, the D-side 122 is etched with a fourth microchannel (not shown in the figure) corresponding to the first microchannel 1111 on the A-side 111. The first microchannel 1111 and the fourth microchannel are connected along the core thickness direction to form a microchannel for hot-side CO2 flow.

[0042] It's easy to understand that by etching the fourth microchannel on surface 122 of the D plate, the cross-sectional area of ​​the microchannel used for hot-side CO2 flow is increased. In other words, the heat transfer area for heat exchange is increased, which facilitates heat exchange between the hot-side CO2 and the cold-side CO2 and cooling water, thus improving heat exchange efficiency. From another perspective, it also helps to reduce the volume of the heat exchanger core.

[0043] In one embodiment, the B-side 112 is etched with a fifth microchannel (not shown in the figure) corresponding to the second microchannel 12111 on the C-side 121. The second microchannel 12111 and the fifth microchannel are connected along the core thickness direction to form a microchannel for cooling water flow.

[0044] It is understandable that etching the fifth microchannel on surface 112 of plate B increases the cross-sectional area of ​​the microchannel used for cooling water flow. In other words, it increases the heat transfer area for heat exchange, which facilitates heat exchange between cooling water and hot-side CO2, thus improving heat exchange efficiency. From another perspective, it also helps to reduce the volume of the heat exchanger core.

[0045] In one embodiment, the B-side 112 is etched with a sixth microchannel (not shown in the figure) corresponding to the third microchannel 12131 of the C-side 121. The third microchannel 12131 and the sixth microchannel are connected along the core thickness direction to form a microchannel for cold-side sCO2 flow.

[0046] Similar to the principle of etching the fourth and fifth microchannels, etching the sixth microchannel on surface 112 of plate B increases the cross-sectional area of ​​the microchannel used for cold-side CO2 flow. In other words, it increases the heat transfer area for heat exchange, facilitating heat exchange between cold-side and hot-side CO2 and improving heat exchange efficiency. From another perspective, it also helps to reduce the volume of the heat exchanger core.

[0047] refer to Figure 1 , Figure 2 , Figure 4 In one embodiment, the first microchannel 1111 is a straight-through structure, which is parallel to the length direction of the first plate 11, and the inlet and outlet of the first microchannel 1111 are respectively located on both sides of the length direction of the first plate 11.

[0048] It is worth noting that in this embodiment, by setting the first microchannel 1111 as a straight-through structure, the structure is simple, the flow resistance is small, and the pressure loss when hot-side sCO2 flows in the first microchannel 1111 can be avoided. In other embodiments, the first channel can be a sine wave, a triangular wave, a square wave, etc.

[0049] refer to Figures 1-3 In one embodiment, the second microchannel 12111 has a Z-shaped baffle structure, with its inlet and outlet located on opposite sides of the width of the second plate 12. The inlet of the second microchannel 12111 is closer to the outlet of the first microchannel 1111 than its outlet. The third microchannel 12131 has a Z-shaped baffle structure, with its inlet and outlet located on opposite sides of the width of the second plate 12. The outlet of the third microchannel 12131 is closer to the inlet of the first microchannel 1111 than its inlet.

[0050] It is understood that in this embodiment, both the second microchannel 12111 and the third microchannel 12131 are configured as Z-shaped baffle structures, and the inlet and outlet of the second microchannel 12111 and the third microchannel 12131 are respectively located on both sides of the width direction of the second plate 12. Furthermore, the inlet of the second microchannel 12111 is closer to the outlet of the first microchannel 1111 than its outlet; similarly, the outlet of the third microchannel 12131 is closer to the inlet of the first microchannel 1111 than its inlet. This arrangement of the second microchannel 12111 and the first microchannel 1111 together form an orthogonal counter-current arrangement, maximizing the heat exchange temperature difference, preventing temperature pinch points, enhancing the heat exchange of cooling water to the hot-side CO2, ensuring heat exchange efficiency, and also providing auxiliary heat dissipation for the partition zone 1212, controlling the thermal stress of the plate. Similarly, the arrangement of the third microchannel 12131 and the arrangement of the first microchannel 1111 together form an orthogonal countercurrent arrangement, which maximizes the heat exchange temperature difference, prevents temperature pinch points, enhances the heat exchange of cold-side sCO2 to hot-side sCO2, and also ensures heat exchange efficiency.

[0051] In other embodiments, the second microchannel 12111 can be a straight-through structure, which is orthogonal to the first microchannel 1111, with the inlet and outlet of the second microchannel 12111 respectively located on both sides of the width direction of the second plate 12; similarly, the third microchannel 12131 can also be a straight-through structure, which is orthogonal to the first microchannel 1111, with the inlet and outlet of the third microchannel 12131 respectively located on both sides of the width direction of the second plate 12.

[0052] In one embodiment, along the arrangement direction of the third microchannel 12131, from its inlet to its outlet, the cross-section of the third microchannel 12131 gradually increases. It is understood that by setting the third microchannel 12131 in a variable cross-section form, heat exchange between the cold-side and hot-side SCO2 can be enhanced while reducing the flow resistance of the cold-side SCO2, further improving the overall system efficiency.

[0053] For the first microchannel 1111, its cross-sectional shape can be any one of semicircular, semi-elliptical, U-shaped, rectangular, or trapezoidal, or other shapes. Similarly, for the second microchannel 12111 and the third microchannel 12131, their cross-sectional shapes can also be any one of semicircular, semi-elliptical, U-shaped, rectangular, or trapezoidal, or other shapes.

[0054] On the other hand, this application provides a heat exchanger for a supercritical carbon dioxide Brayton cycle system, which employs the aforementioned printed circuit board type heat exchanger core. The specific structure of the heat exchanger core is as described in the foregoing embodiments. Since this heat exchanger adopts the technical solutions of the foregoing embodiments, it at least has the beneficial effects brought about by the technical solutions of the foregoing embodiments, which will not be elaborated further here.

[0055] This application also provides a supercritical carbon dioxide Brayton cycle system, which employs the aforementioned heat exchanger. The specific structure of the heat exchanger is as described in the foregoing embodiments. Since this cycle system adopts the technical solutions of the foregoing embodiments, it at least has the beneficial effects brought about by the technical solutions of the foregoing embodiments, which will not be elaborated further here.

[0056] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A printed circuit board type heat exchanger core for use in a supercritical carbon dioxide Brayton cycle system, characterized in that, The system comprises several first plates and several second plates arranged alternately in a stacked manner. The two sides of the first plates are A-side and B-side, and the two sides of the second plates are C-side and D-side. For adjacent first plates and second plates, the A-side and D-side are adjacent, and the B-side and C-side are adjacent. The A-side is etched with a first microchannel for hot-side CO2 flow. The C-side includes a cooling zone, a partition zone, and a regenerating zone, which are distributed sequentially along the length of the C-side. The cooling zone is etched with a second microchannel for cooling water flow, and the regenerating zone is etched with a third microchannel for cold-side CO2 flow. The partition zone is not etched with microchannels. In operation, the hot-side CO2 flowing through the first microchannel exchanges heat with the cold-side CO2 flowing through the third microchannel and the cooling water flowing through the second microchannel.

2. The printed circuit board type heat exchanger core according to claim 1, characterized in that, The D-plate surface is etched with a fourth microchannel corresponding to the first microchannel on the A-plate surface. The first microchannel and the fourth microchannel are connected along the core thickness direction to form a microchannel for hot-side CO2 flow.

3. The printed circuit board type heat exchanger core according to claim 1, characterized in that, The B-side is etched with a fifth microchannel corresponding to the second microchannel on the C-side. The second microchannel and the fifth microchannel are aligned along the core thickness direction to form a microchannel for cooling water flow.

4. The printed circuit board type heat exchanger core according to claim 1, characterized in that, The B-side is etched with a sixth microchannel corresponding to the third microchannel on the C-side. The third microchannel and the sixth microchannel are aligned along the core thickness direction to form a microchannel for cold-side CO2 flow.

5. A printed circuit board type heat exchanger core according to any one of claims 1-4, characterized in that, The first microchannel is a straight-through structure, which is parallel to the length direction of the first plate. The inlet and outlet of the first microchannel are respectively located on both sides of the length direction of the first plate.

6. A printed circuit board type heat exchanger core according to claim 5, characterized in that, The second microchannel has a Z-shaped baffle structure, with its inlet and outlet located on opposite sides of the width of the second plate. The inlet of the second microchannel is closer to the outlet of the first microchannel than the outlet of the second microchannel. The third microchannel has a Z-shaped baffle structure, with its inlet and outlet located on opposite sides of the width of the second plate. The outlet of the third microchannel is closer to the inlet of the first microchannel than its inlet.

7. A printed circuit board type heat exchanger core according to claim 6, characterized in that, Along the layout direction of the third microchannel, from its inlet to its outlet, the cross-section of the third microchannel gradually increases.

8. A printed circuit board type heat exchanger core according to claim 6 or 7, characterized in that, The cross-sectional shape of the first microchannel is any one of semicircular, semi-elliptical, U-shaped, rectangular, or trapezoidal; the cross-sectional shape of the second microchannel is any one of semicircular, semi-elliptical, U-shaped, rectangular, or trapezoidal; and the cross-sectional shape of the third microchannel is any one of semicircular, semi-elliptical, U-shaped, rectangular, or trapezoidal.

9. A heat exchanger for a supercritical carbon dioxide Brayton cycle system, characterized in that, Includes the printed circuit board type heat exchanger core as described in any one of claims 1-8.

10. A supercritical carbon dioxide Brayton cycle system, characterized in that, Includes the heat exchanger as described in claim 9.

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