Low-flow-resistance liquid cooling plate and secondary composite light and heat component preparation method

Abstract

The application discloses a low-flow-resistance liquid cooling plate and a secondary composite light-heat component preparation method, relates to the technical field of liquid cooling plates, and comprises a plate body, at least one inlet, at least one outlet, a collecting channel, a plurality of branch channels and a flow separation area. The collecting channels are arranged on both sides of the plate body. The plurality of branch channels are arranged at intervals and are connected between the collecting channels on both sides. The flow separation area is arranged on the plate body and is a closed area or a solid separation area that does not participate in fluid flow. The flow separation area is located in the arrangement area of the plurality of branch channels to separate the plurality of branch channels into at least two branch channel groups. According to the parallel connection design of the collecting channel and the plurality of branch channels, the cooling medium is distributed to a plurality of shorter flow branches, the single fluid path is shortened, the resistance along the path is reduced, and the pressure drop of the liquid cooling plate inlet and outlet is reduced. The flow separation area blocks the short-circuit flow between the inlet and the outlet, and cooperates with the flow distribution and pressure equalization of the collecting channel.

Description

Technical Field

[0001] This invention relates to the field of liquid cooling plate technology, and in particular to a low flow resistance liquid cooling plate and a method for preparing a secondary composite photothermal module. Background Technology

[0002] In the field of photovoltaic-thermal integration technology, photovoltaic modules generate a large amount of heat in their cells while converting solar energy into electrical energy. If this heat is not dissipated in time, it will not only cause the operating temperature of the photovoltaic module to rise and the photoelectric conversion efficiency to decrease, but also accelerate the aging of the encapsulation materials and shorten the module's lifespan. Therefore, it is usually necessary to install a liquid cooling plate on the back of the photovoltaic module to remove heat through the circulation of the cooling medium and recover and reuse the waste heat to achieve synergy between photovoltaic power generation and thermal energy utilization.

[0003] Currently, the liquid cooling plates used in photovoltaic thermal modules are mostly of serpentine flow channel structure or single direct-flow channel structure. In these structures, the cooling medium needs to flow through the entire plate along a single continuous path. The fluid path is long and the friction resistance is high, resulting in a high pressure drop between the inlet and outlet of the liquid cooling plate, which requires a high head for the circulating pump. At the same time, due to the lack of an effective flow distribution and pressure equalization structure, the flow distribution of the cooling medium in different areas of the plate is difficult to be uniform, and local stagnation or short-circuit flow is prone to occur, resulting in uneven temperature distribution on the plate surface, which in turn affects the heat exchange efficiency and the long-term stability of the module.

[0004] In the composite process of liquid-cooled plates and photovoltaic laminates, existing technologies typically use traditional POE or EVA films to directly bond the liquid-cooled plates and photovoltaic laminates through a single high-temperature, long-duration lamination and curing process. Due to the significant difference in thermal expansion coefficients between the metal liquid-cooled plates and the photovoltaic laminates, their shrinkage is inconsistent during the cooling process after high-temperature curing. This results in substantial residual stress at the composite interface, easily leading to module warping or even delamination. Simultaneously, the high-temperature, long-duration lamination conditions increase the risk of microcracks in the photovoltaic cells due to thermal stress and mechanical pressure, affecting the finished product yield and the reliability of the modules.

[0005] Therefore, optimizing the flow channel structure of the liquid cooling plate to reduce flow resistance, improve the uniformity of the flow distribution of the cooling medium, and improve the composite process of the liquid cooling plate and photovoltaic laminate to reduce residual stress at the interface and avoid module warping and delamination are technical problems that urgently need to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a low flow resistance liquid-cooled plate and a secondary composite photothermal module, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a low flow resistance liquid cooling plate, comprising a plate body, at least one inlet, at least one outlet, a manifold, multiple branch channels, and a flow isolation zone; The confluence channels are respectively disposed on both sides of the plate; The multiple branch channels are arranged at intervals and connected between the confluence channels on both sides; The flow-blocking zone is disposed on the plate and is a closed area or solid partition area that does not participate in the flow of fluid. The flow-blocking zone is located in the area where the multiple branch channels are arranged, so as to divide the multiple branch channels into at least two branch channel groups. At least one of the inlets is connected to the manifold on one side of the plate, and at least one of the outlets is connected to the manifold on the other side of the plate. The cooling medium can enter the manifold through the inlet, be distributed to multiple branch channels through the manifold, and then be discharged through the outlet after being collected by the manifold.

[0008] Preferably, the manifolds all extend along the first direction of the plate and are respectively disposed on opposite sides of the plate in the second direction; All of the aforementioned tributary channels extend along the second direction and are arranged in parallel at intervals along the first direction; The flow-blocking zone extends along the second direction to divide the plurality of branch channels into two branch channel groups.

[0009] Preferably, the number of imports and exports are both two; The two inlets are respectively located on both sides of the flow isolation zone, and both are connected to the flow channel on one side of the plate. The two outlets are respectively located on both sides of the flow isolation zone, and both are connected to the flow channel on the other side of the plate.

[0010] Preferably, the cross-sectional area of ​​the manifold is larger than the cross-sectional area of ​​any of the branch channels, and the manifold is used to split, merge, buffer, or equalize the cooling medium. The cross-sectional width of both the confluence channel and the branch channel is greater than their respective cross-sectional height; The multiple branch channels are long, parallel channels arranged at equal intervals.

[0011] Preferably, the length of the plate is 2000mm to 2500mm and the width is 1000mm to 1300mm; The width of the manifold is 10mm to 30mm and the height is 5mm to 15mm; The number of branch channels is 30 to 100, and the width of the branch channels is 8mm to 20mm and the height is 2mm to 6mm; The diameters of both the inlet and the outlet are 15mm to 30mm.

[0012] Preferably, the flow isolation zone is provided with a plurality of mounting holes, which are spaced apart along the extension direction of the flow isolation zone, and all of the mounting holes are arranged to avoid the confluence channel and the plurality of branch channels.

[0013] Preferably, the plate is made of aluminum alloy plate, stainless steel plate or copper alloy plate.

[0014] Preferably, the manifold and the branch channels are formed by stamping and welding, roll forming, brazing, laser welding, extrusion forming or blow molding.

[0015] A secondary composite photovoltaic thermal module includes a photovoltaic laminate, a thermoplastic polyolefin film, and a low flow resistance liquid cooling plate; The photovoltaic laminate is a photovoltaic laminate formed by a single lamination and encapsulation. The light-receiving surface of the photovoltaic laminate is covered with a black light-absorbing coating. The multiple mounting holes are used to avoid the current leads of the photovoltaic laminate. The thermoplastic polyolefin film is sandwiched between the back of the photovoltaic laminate and the plate of the low flow resistance liquid cooling plate, and the thickness of the thermoplastic polyolefin film is 0.2mm to 0.5mm. The photovoltaic laminate, the thermoplastic polyolefin film, and the low flow resistance liquid cooling plate are laminated together to form an integrated structure. The thermoplastic polyolefin film fills the interface gap between the photovoltaic laminate and the low flow resistance liquid cooling plate and forms a continuous adhesive layer. It also includes a junction box and a frame. The junction box is electrically connected to the current lead of the photovoltaic laminate, and the frame is a polyurethane frame and is disposed on the outer periphery of the photovoltaic module.

[0016] A method for preparing a secondary composite photothermal module includes the following steps: S1. Provides photovoltaic laminates formed by one-time lamination and encapsulation, thermoplastic polyolefin films, and low flow resistance liquid cooling plates with multiple parallel branch channels; S2. The low flow resistance liquid cooling plate is pretreated, the pretreatment including at least one of degreasing, cleaning, drying and surface activation treatment, and the low flow resistance liquid cooling plate is tested for air tightness. S3. The thermoplastic polyolefin film is laid on the back of the photovoltaic laminate, and the low flow resistance liquid cooling plate is stacked on the side of the thermoplastic polyolefin film away from the photovoltaic laminate. The mounting holes on the low flow resistance liquid cooling plate are positioned to avoid the current lead wires of the photovoltaic laminate, thus forming the laminate to be laminated. S4. Perform a first composite treatment on the component to be laminated. Under vacuum conditions, heat and pressurize the component to be laminated for 10 min to 15 min at a temperature of 100℃~120℃ and a pressure of 50kPa~70kPa to soften the thermoplastic polyolefin film and fill the interface gap between the back of the photovoltaic laminate and the low flow resistance liquid cooling plate. S5. Perform a second shaping treatment on the laminate after the first composite treatment. Under the condition of maintaining pressure, perform pressure holding and cooling at a temperature of 40℃~60℃ and a pressure of 40kPa~60kPa for 10min~15min to shape the thermoplastic polyolefin film and to form an integrated secondary composite photovoltaic thermal component with the photovoltaic laminate, the thermoplastic polyolefin film and the low flow resistance liquid cooling plate. S6. Cool the component after the second shaping process to room temperature, remove excess adhesive film from the edges, and check whether there is any interference between the mounting holes and the current leads. Then install the junction box and frame. S7. The obtained secondary composite photovoltaic module is tested, and the test includes at least one of the following: appearance inspection, insulation withstand voltage test, grounding continuity test, airtightness test, flow resistance test, thermal cycling test, and photovoltaic electrical performance test.

[0017] The technical effects and advantages of this invention are as follows: This invention utilizes a partitioned parallel design of the manifold and multiple branch channels to distribute the cooling medium into multiple shorter flow branches, shortening the single fluid path, reducing frictional resistance, and decreasing the pressure drop at the inlet and outlet of the liquid cooling plate. The flow isolation zone blocks the short-circuit flow between the inlet and outlet, and in conjunction with the flow diversion and pressure equalization effects of the manifold, the flow distribution of the cooling medium in various areas of the plate surface tends to be uniform, reducing local stagnation and improving heat exchange consistency. This invention uses a thermoplastic polyolefin film as a composite layer, and performs heating and pressure bonding in the first chamber at a relatively low temperature of 100℃~120℃, which is different from the traditional POE / EVA high temperature long time curing system; then, it is subjected to pressure holding and cooling at 40℃~60℃ in the second chamber, so that the thermoplastic polyolefin film cools and sets, releases the residual stress at the interface between the board and the photovoltaic laminate, and reduces the risk of warping and delamination caused by the difference in the thermal expansion coefficients of the two. The photovoltaic laminate of the present invention is first laminated and encapsulated to form a stable structure, and then laminated with the plate body for a second time. During the lamination process, the current lead wire is positioned and avoided through the mounting holes, and the risk of mechanical damage to the solar cell caused by the surface structure of the plate body is reduced by pressure regulation and buffer support, thereby reducing microcracks in the solar cell. At the same time, the thermoplastic polyolefin film fills the interface gap between the photovoltaic laminate and the plate body and forms a continuous adhesive layer, reducing air gaps and lowering the interface thermal resistance. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a top view structural diagram of the present invention; Figure 2 This is an exploded structural diagram of the secondary composite photothermal component of the present invention; Figure 3 This is a schematic diagram of the structure of the secondary composite photothermal component application system of the present invention; Figure 4 This is a simulation diagram of the pressure distribution in the confluence channel and branch channel of the present invention.

[0019] In the attached diagram: 1. Plate; 2. Manifold; 3. Branch duct; 4. Isolation zone; 5. Mounting hole; 6. Inlet; 7. Outlet; 8. Thermoplastic polyolefin film; 9. Photovoltaic laminate; 10. Junction box; 11. Current lead; 12. Frame; 20. Control unit; 21. Micro inverter; 22. Water tank; 23. Heating rod; 24. Heat exchange coil; 25. Water pump; 26. First temperature sensor; 27. Second temperature sensor. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides, for example Figures 1-4 The invention illustrates a method for preparing a low flow resistance liquid-cooled plate and a secondary composite photothermal module.

[0022] Example 1: As Figure 1 and Figure 2 As shown, this embodiment provides a low flow resistance liquid cooling plate, including a plate body 1, at least one inlet 6, at least one outlet 7, a manifold 2, multiple branch channels 3, and a flow isolation zone 4.

[0023] The plate 1 has a flat, plate-like structure with internal or surface channels for the flow of cooling medium. The plate 1 is made of aluminum alloy, stainless steel, or copper alloy. Utilizing the excellent thermal conductivity and corrosion resistance of these materials, the plate 1 can effectively transfer heat from the back of the photovoltaic laminate 9 to the cooling medium within the channels, while ensuring structural stability during long-term operation. The plate 1 has a length of 2000mm–2500mm and a width of 1000mm–1300mm, thus adapting to the back dimensions of conventional photovoltaic modules and enabling large-area heat exchange.

[0024] The manifolds 2 are respectively located on both sides of the plate 1. The manifolds 2 extend along the first direction of the plate 1 and are respectively located on opposite sides of the plate 1 in the second direction. The cross-sectional area of ​​the manifold 2 is larger than that of any branch channel 3, and is used for distributing, converging, buffering, or equalizing the cooling medium, thereby ensuring that the cooling medium entering the plate 1 is evenly distributed to each branch channel 3, reducing pressure fluctuations caused by sudden changes in flow rate, and improving the pressure consistency at the inlet of each branch channel 3. The cross-sectional width of the manifold 2 is larger than its cross-sectional height, thus obtaining a larger flow cross-sectional area within the limited thickness of the plate 1, while reducing the overall thickness of the plate 1. The width of the manifold 2 is 10mm to 30mm, and the height is 5mm to 15mm.

[0025] Multiple branch channels 3 are spaced apart and connected to the confluence channels 2 on both sides. Each branch channel 3 extends along a second direction and is arranged in parallel with intervals along a first direction. The branch channels 3 are elongated channels arranged in parallel at equal intervals. The cross-sectional width of each branch channel 3 is greater than its cross-sectional height to form a flat flow channel within the thin plate 1, increasing the contact heat exchange area between the cooling medium and the plate 1. The number of branch channels 3 is 30 to 100, with a width of 8 mm to 20 mm and a height of 2 mm to 6 mm. The cross-sectional area, length, and spacing of each branch channel 3 can be designed according to the dimensions of the plate 1, the heat distribution of the photovoltaic module, the flow rate of the circulating pump, and the allowable pressure drop, thereby matching the flow channel parameters with the heat source distribution and system operating conditions to avoid localized overheating or flow dead zones.

[0026] The manifold 2 and branch channels 3 are formed by stamping followed by welding, roll forming, brazing, laser welding, extrusion forming, or blow molding, thus adapting to different materials and mass production needs. After forming, it should be ensured that the inlet 6 and outlet 7 are reliably connected to the channel structure, and that the channels are unblocked to prevent localized temperature rise caused by obstructed flow of cooling medium.

[0027] The flow-blocking zone 4 is a closed area or solid partition area disposed on the plate 1 that does not participate in fluid flow. The flow-blocking zone 4 is located within the area where multiple branch channels 3 are arranged, so as to divide the multiple branch channels 3 into at least two branch channel groups. In this embodiment, the flow-blocking zone 4 extends along the second direction to divide the multiple branch channels 3 into two branch channel groups. The two confluence channels 2 pass through the ends of the flow-blocking zone 4 and remain continuously connected, preventing the cooling medium from being discharged from the outlet 7 without sufficient heat exchange, thereby improving the utilization rate of the heat exchange area; at the same time, the flow-blocking zone 4 guides the cooling medium into the branch channel 3 in a predetermined direction, so that the fluid forms an effective heat exchange path within the plate 1 and prevents local stagnation.

[0028] The flow isolation zone 4 is provided with multiple mounting holes 5, which are spaced apart along the extension direction of the flow isolation zone 4. All mounting holes 5 are positioned to avoid the confluence channel 2 and multiple branch channels 3, thereby preventing the openings from interfering with the flow of the cooling medium or damaging the channel sealing. The mounting holes 5 can also be located in other non-channel areas. The mounting holes 5 can be used for positioning the liquid cooling plate, thereby ensuring the alignment accuracy of the liquid cooling plate and the photovoltaic laminate 9 during subsequent lamination and bonding.

[0029] At least one inlet 6 is connected to a manifold 2 on one side of the plate 1, and at least one outlet 7 is connected to a manifold 2 on the other side of the plate 1. The diameters of both inlet 6 and outlet 7 are 15mm to 30mm to match external circulation pipe interfaces and reduce local resistance at pipe connections. The cooling medium can be water, a water-glycol mixture, antifreeze, or other heat exchange media suitable for liquid-cooled plates. The cooling medium can enter the manifold 2 through inlet 6, be distributed to multiple branch channels 3 via manifold 2, and then be collected again via manifold 2 before being discharged through outlet 7.

[0030] In this embodiment, there are two inlets 6 and two outlets 7. The two inlets 6 are respectively located on both sides of the flow-blocking zone 4 and are both connected to the confluence channel 2 on one side of the plate 1; the two outlets 7 are respectively located on both sides of the flow-blocking zone 4 and are both connected to the confluence channel 2 on the other side of the plate 1. By setting inlets 6 and outlets 7 on both sides of the flow-blocking zone 4, the cooling medium can enter the corresponding branch channel groups in sections, shortening the flow path in each area, further reducing the friction loss of a single branch, and improving the uniformity of flow distribution across the entire plate surface.

[0031] After entering the plate 1 through inlet 6, the cooling medium is distributed to multiple branch channels 3 via manifold 2. Since the branch channels 3 are distributed in parallel, the cooling medium can flow simultaneously within a large heat exchange area, reducing the flow rate and velocity of a single branch channel 3, thereby reducing flow resistance and decreasing the total pressure drop between inlet 6 and outlet 7. After flowing through the branch channels 3, the cooling medium is collected in manifold 2 and finally discharged from outlet 7. Through the zoned combination of manifold 2 and multiple branch channels 3, the liquid cooling plate as a whole can form a shorter and more uniform flow path, reducing local resistance and friction loss, improving the utilization rate of the heat exchange area, and avoiding uneven heat dissipation caused by no or low flow in local areas.

[0032] like Figure 4 As shown, the cooling medium enters through inlet 6 and, under the guidance of the flow-blocking zone 4, enters multiple branch channels 3. After being split and merged through the confluence channel 2, it is discharged through outlet 7. The pressure distribution simulation results show that the pressure change inside the liquid cooling plate is relatively continuous, and no obvious local high-pressure concentration areas appear. This indicates that the parallel arrangement of multiple branch channels 3 and the distribution structure of the confluence channel 2 can reduce the flow resistance of a single path and improve the flow uniformity of the cooling medium within the plate 1.

[0033] Example 2: Figure 2 As shown, in this embodiment, a secondary composite photothermal component is provided, including a photovoltaic laminate 9, a thermoplastic polyolefin film 8, and the aforementioned low flow resistance liquid cooling plate.

[0034] The photovoltaic laminate 9 is a photovoltaic laminate formed through a single lamination process, including a front panel, encapsulating film, cell strings, and a back panel or rear encapsulation layer. This ensures that the cells have a stable encapsulation structure before secondary lamination, reducing the risk of breakage during subsequent composite processes. The light-receiving surface of the photovoltaic laminate 9 is set to be entirely black to improve the light absorption rate, increase the module's heat generation power, and improve its integration with the building's appearance. Current leads 11 are led out from the photovoltaic laminate 9.

[0035] A thermoplastic polyolefin film 8 is sandwiched between the back of the photovoltaic laminate 9 and the plate 1 of the low-flow-resistance liquid cooling plate. The thermoplastic polyolefin film 8 is made of thermoplastic polyolefin, possessing weather resistance, adhesion, and certain insulation properties, thus maintaining adhesive reliability during long-term outdoor operation and preventing electrochemical corrosion between the photovoltaic laminate 9 and the metal liquid cooling plate. The thickness of the thermoplastic polyolefin film 8 is 0.2mm to 0.5mm. During the secondary lamination process, the thermoplastic polyolefin film 8 softens upon heating and, under vacuum and pressure, adheres tightly to the back of the photovoltaic laminate 9 and the surface of the plate 1, filling the small uneven areas between them, reducing air gaps, and thus lowering the interfacial thermal resistance. This allows the heat generated by the photovoltaic laminate 9 to be rapidly transferred to the plate 1 through the thermoplastic polyolefin film 8, and then carried away by the cooling medium flowing within the liquid cooling plate.

[0036] The low flow resistance liquid cooling plate is provided with multiple mounting holes 5. The multiple mounting holes 5 are used to avoid the current lead wires 11 of the photovoltaic laminate 9, thereby avoiding mechanical interference between the lead wires and the plate body 1 during lamination and ensuring that the current lead wires 11 can be smoothly connected to the junction box 10.

[0037] The photovoltaic laminate 9, the thermoplastic polyolefin film 8, and the low flow resistance liquid cooling plate are laminated together to form an integrated structure. The thermoplastic polyolefin film 8 fills the interface gap between the photovoltaic laminate 9 and the low flow resistance liquid cooling plate and forms a continuous adhesive layer, thereby improving the structural strength and long-term service stability of the module.

[0038] The secondary composite solar thermal module also includes a junction box 10 and a frame 12. The junction box 10 is electrically connected to the current lead 11 of the photovoltaic laminate 9 to realize the power output of the photovoltaic module. The frame 12 is a polyurethane frame, which is lightweight and strong. It is set on the outer periphery of the solar thermal module, thereby reducing the overall weight of the module while meeting mechanical strength requirements and facilitating outdoor installation.

[0039] Through the above structure, the secondary composite photovoltaic module can reduce the residual stress after composite and improve the flatness. During the preparation process, it can reduce the risk of pressure damage to photovoltaic laminate 9 and microcracks in the battery cells, improve the finished product qualification rate, and improve the stability of power output and the pressure bearing reliability of the liquid cooling plate during outdoor operation.

[0040] Example 3: In this example, a method for preparing a secondary composite photothermal module is provided, including the following steps: S1. Provides a photovoltaic laminate 9, a thermoplastic polyolefin film 8, and a low flow resistance liquid cooling plate with multiple parallel branch channels 3, which are formed by one-time lamination and encapsulation. This allows the photovoltaic laminate 9 to be cured and shaped before secondary lamination, reducing the thermal shock and mechanical damage to the cells caused by secondary lamination.

[0041] S2. Pre-treat the low-flow-resistance liquid-cooled plate. Pre-treatment includes at least one of degreasing, cleaning, drying, and surface activation to remove surface contaminants and improve surface activity. If necessary, the side of the plate in contact with the thermoplastic polyolefin film 8 can be roughened, coated with a primer, or subjected to plasma treatment to improve the adhesion strength between the thermoplastic polyolefin film 8 and the liquid-cooled plate. Simultaneously, perform an airtightness test on the low-flow-resistance liquid-cooled plate by introducing compressed air or liquid medium into the inlet 6, sealing the outlet 7, or testing the pressure retention under a set pressure to determine if there is any leakage in the liquid-cooled plate, thereby preventing photovoltaic module failure due to cooling medium leakage after lamination. After passing the test, proceed to the next process.

[0042] S3. Prepare the photovoltaic laminate 9 and complete the treatment of the current lead wire 11 to ensure that the lead wire is not damaged by compression during the lamination process. Lay the thermoplastic polyolefin film 8 on the back of the photovoltaic laminate 9 so that the thermoplastic polyolefin film 8 covers the area to be laminated with the liquid cooling plate. Then, stack the low flow resistance liquid cooling plate on the side of the thermoplastic polyolefin film 8 away from the photovoltaic laminate 9. Position the plate by avoiding the current lead wire 11 of the photovoltaic laminate 9 through the mounting holes 5 on the low flow resistance liquid cooling plate, so that the back of the plate 1 and the photovoltaic laminate 9 are accurately aligned to form the laminate, thereby preventing edge overflow or local incomplete lamination caused by misalignment during the lamination process.

[0043] S4. Place the stacked components to be laminated into the first chamber of the photovoltaic laminator, and perform vacuuming, heating, and pressurization. Under vacuum conditions, heat and pressurize the components to be laminated at a temperature of 100℃~120℃ and a pressure of 50kPa~70kPa for 10min~15min. The thermoplastic polyolefin film 8 differs from the traditional POE / EVA high-temperature long-term curing system, allowing for a lower temperature required for secondary lamination, thereby reducing the risk of microcracks in the solar cells caused by prolonged high-temperature heating of the photovoltaic laminate 9. During the lamination process, the thermoplastic polyolefin film 8 softens and becomes fluid upon heating, expelling interfacial air under vacuum conditions and filling the interfacial gap between the back of the photovoltaic laminate 9 and the low-flow-resistance liquid cooling plate under pressure, thus forming a dense adhesive interface and reducing interfacial thermal resistance; simultaneously, through pressure regulation and buffer support, the risk of mechanical damage to the solar cells caused by the surface structure of the low-flow-resistance liquid cooling plate is reduced.

[0044] S5. Perform a second shaping treatment on the laminated component after the first composite treatment. Transfer the component into the second chamber of the photovoltaic laminator, and under the conditions of maintaining pressure and temperature at 40℃~60℃, perform pressure holding and cooling at 40kPa~60kPa for 10min~15min. During the cooling process, the thermoplastic polyolefin film 8 cools and shapes, forming an integrated secondary composite photovoltaic thermal module with the photovoltaic laminate 9, the thermoplastic polyolefin film 8, and the low flow resistance liquid cooling plate. Pressure holding and cooling can reduce the residual stress at the interface between the metal liquid cooling plate and the photovoltaic laminate 9 caused by the difference in the coefficient of thermal expansion, thereby improving the flatness and composite reliability of the photovoltaic thermal module and reducing the risk of warping and delamination during long-term operation.

[0045] S6. After the second shaping process, the component is cooled to room temperature to obtain a flat photothermal laminate. Excess adhesive film is removed from the edges, and the mounting holes 5 and current leads 11 are checked for interference to ensure the reliability of subsequent electrical connections. Then, the junction box 10 and frame 12 are installed, the junction box 10 is electrically connected to the current leads 11, and the frame 12 is installed on the outer periphery of the component, thereby completing the electrical and mechanical encapsulation of the component.

[0046] S7. The obtained secondary composite solar thermal modules are tested, including at least one of the following: appearance inspection, insulation withstand voltage test, grounding continuity test, airtightness test, flow resistance test, thermal cycling test, and photovoltaic electrical performance test, so as to screen out products with composite defects or substandard performance, and ensure the finished product qualification rate and long-term operational reliability of the modules.

[0047] Example 4: In this example, the plate 1 is made of aluminum alloy plate, with a length of 2376mm and a width of 1120mm. It is composed of two substrates, each with a wall thickness of 0.8mm, forming a manifold 2 and branch channels 3 inside. There are two manifolds 2, each with a width of 18mm and a height of 7mm. There are 100 branch channels 3, each with a width of 14mm and a height of 3mm, arranged parallel to each other at equal intervals along the width direction of the plate 1. There is one flow-blocking zone 4, extending along the second direction, with a dimension of 1052mm along the second direction and a dimension of 548mm along the first direction, dividing the 100 branch channels 3 into two branch channel groups. There are two inlets 6 and two outlets 7, each with a diameter of 20mm, respectively located on both sides of the flow-blocking zone 4. The thermoplastic polyolefin film 8 has a thickness of 0.32mm and a size of 2374mm × 1126mm.

[0048] The confluence channel 2 and the branch channel 3 are formed by stamping and then welding.

[0049] During preparation, the lamination temperature in S4 was set to 110℃, the pressure to 60kPa, and the lamination time to 12min. In S5, the temperature of the second chamber was set to 50℃, the pressure to 50kPa, and the pressure holding and cooling time to 12min.

[0050] Example 5: In this example, plate 1 is made of stainless steel, with a length of 2000mm and a width of 1000mm. It is composed of two substrates, each with a wall thickness of 1.0mm, which together form a manifold 2 and branch channels 3. The manifold 2 has a width of 15mm and a height of 8mm. There are 60 branch channels 3, each with a width of 10mm and a height of 3mm. The manifold 2 and branch channels 3 are formed by a roll forming process.

[0051] The remaining structure and preparation steps are the same as in Example 1.

[0052] Application methods: such as Figure 3 As shown, this embodiment provides an application system for a secondary composite photothermal module. The application system includes a photothermal module, a micro inverter 21, a water tank 22, a heating rod 23, a heat exchange coil 24, a water pump 25, a first temperature sensor 26, a second temperature sensor 27, and a control unit 20.

[0053] The solar thermal module is the aforementioned secondary composite solar thermal module, which includes a photovoltaic laminate 9, a thermoplastic polyolefin film 8 or a flexible adhesive layer, and a low-flow-resistance liquid cooling plate. The low-flow-resistance liquid cooling plate is laminated to the back of the photovoltaic laminate 9 through the thermoplastic polyolefin film 8 and is provided with an inlet 6 and an outlet 7. In this embodiment, there are two solar thermal modules, and the low-flow-resistance liquid cooling plates of the two solar thermal modules are connected in series through pipelines to form a heat exchange section of the module.

[0054] Inlet 6 and outlet 7 are connected to an external circulation pipeline, which is connected to the heat exchange coil 24 inside the water tank 22. A water pump 25 is installed on the external circulation pipeline to drive the cooling medium to circulate between the low flow resistance liquid-cooled plate of the photothermal component and the heat exchange coil 24.

[0055] The micro-inverter 21 is connected to the electrical output terminal of the solar thermal module to convert the direct current generated by the photovoltaic laminate 9 into alternating current for use by the load or for grid connection. The heating rod 23 is installed in the water tank 22 to provide auxiliary heating when there is insufficient sunlight or the water temperature in the water tank 22 has not reached the set temperature, thereby ensuring the continuity of hot water supply.

[0056] The first temperature sensor 26 is located at the photothermal assembly to detect the temperature of the photothermal assembly or the low-flow-resistance liquid cooling plate. The second temperature sensor 27 is located at the water tank 22 to detect the water temperature inside the water tank 22. The control unit 20 is connected to the first temperature sensor 26, the second temperature sensor 27, the water pump 25, and the heating rod 23, and controls the operating status of the water pump 25 and the heating rod 23 according to the detected temperature, thereby coordinating heat generation and consumption according to actual operating conditions and reducing ineffective cycle energy consumption.

[0057] During system operation, sunlight irradiates the solar thermal module, and the photovoltaic laminate 9 generates electricity, which is converted into AC output by the micro-inverter 21. Simultaneously, the photovoltaic laminate 9 generates heat during power generation, which is transferred to the low-resistance liquid cooling plate via the thermoplastic polyolefin film 8. The cooling medium, driven by the water pump 25, enters the low-resistance liquid cooling plate through inlet 6, absorbs heat from the back of the photovoltaic laminate 9 within the plate, and is then discharged through outlet 7 into the heat exchange coil 24 within the water tank 22. The cooling medium transfers heat to the water in the water tank 22 through the heat exchange coil 24, and the cooled medium then returns to the solar thermal module, forming a circulating heat exchange.

[0058] When the first temperature sensor 26 detects that the temperature of the photothermal component is higher than the set temperature, and the second temperature sensor 27 detects that the water temperature in the water tank 22 is lower than the set temperature, the control unit 20 starts the water pump 25 to circulate the cooling medium, thereby reducing the operating temperature of the photothermal component and recovering heat from the back of the component. When the water temperature in the water tank 22 reaches the set temperature, or the temperature of the photothermal component is lower than the set temperature, the control unit 20 stops the water pump 25 or reduces the operating power of the water pump 25 to reduce ineffective circulation energy consumption.

[0059] When the water temperature in the water tank 22 is lower than the set water temperature and there is insufficient light, the control unit 20 activates the heating rod 23 to provide auxiliary heating to the water in the water tank 22 to ensure the supply of hot water.

[0060] When using black-looking photovoltaic laminates 9, the solar thermal module exhibits good architectural integration. Depending on the application scenario, an insulation layer can also be installed on the back of the solar thermal module or the outside of the circulation pipeline to reduce heat loss and improve the heat absorption efficiency of the working fluid.

[0061] Through the above application methods, the solar thermal module can simultaneously achieve photovoltaic power generation and heat recovery on the back of the module, taking into account architectural aesthetics, power output, and heat utilization. The low-flow-resistance liquid-cooled plate reduces the circulation resistance of the cooling medium through a multi-branch flow channel 3 parallel connection and a distribution structure via a manifold 2, improving the uniformity of heat exchange on the back of the module. The heat exchange coil 24 transfers the recovered heat to the water in the water tank 22, the micro-inverter 21 outputs power, and the control unit 20 coordinates the operation of the water pump 25 and the heating rod 23 based on the module temperature and the water tank 22 temperature. The number of solar thermal modules can be adjusted according to hot water usage and power demand, thereby improving the overall energy utilization efficiency of the system.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-flow-resistance liquid cooling plate, characterized in that, It includes a plate (1), at least one inlet (6), at least one outlet (7), a confluence channel (2), multiple branch channels (3), and a flow isolation zone (4); The manifolds (2) are respectively disposed on both sides of the plate (1); Multiple branch channels (3) are arranged at intervals and connected to the confluence channels (2) on both sides. The flow-blocking zone (4) is disposed on the plate (1) and is a closed area or solid separation area that does not participate in the flow of fluid. The flow-blocking zone (4) is located in the arrangement area of ​​multiple branch channels (3) to divide the multiple branch channels (3) into at least two branch channel groups. At least one of the inlets (6) is connected to the manifold (2) on one side of the plate (1), and at least one of the outlets (7) is connected to the manifold (2) on the other side of the plate (1). The cooling medium can enter the manifold (2) through the inlet (6), be distributed to multiple branch channels (3) through the manifold (2), and then be discharged through the outlet (7) after being collected through the manifold (2).

2. The low flow resistance liquid cooling plate according to claim 1, characterized in that, The manifolds (2) all extend along the first direction of the plate (1) and are respectively located on opposite sides of the plate (1) in the second direction; Multiple of the aforementioned tributary channels (3) extend along the second direction and are arranged in parallel at intervals along the first direction; The flow isolation zone (4) extends along the second direction to divide the plurality of the branch channels (3) into two branch channel groups.

3. A low flow resistance liquid cooling plate according to claim 2, characterized in that, The quantity of both the import (6) and the export (7) is two; The two inlets (6) are respectively located on both sides of the flow isolation zone (4) and are connected to the flow channel (2) on one side of the plate (1); The two outlets (7) are respectively located on both sides of the flow isolation zone (4) and are connected to the flow channel (2) on the other side of the plate (1).

4. A low flow resistance liquid cooling plate according to claim 1, characterized in that, The cross-sectional area of ​​the manifold (2) is larger than the cross-sectional area of ​​any of the branch channels (3), and the manifold (2) is used to divide, merge, buffer or equalize the cooling medium; The cross-sectional width of the confluence channel (2) and the branch channel (3) is greater than their respective cross-sectional height; The multiple branch channels (3) are long, parallel channels with equal spacing.

5. A low flow resistance liquid cooling plate according to claim 4, characterized in that, The length of the plate (1) is 2000mm to 2500mm and the width is 1000mm to 1300mm; The width of the manifold (2) is 10mm to 30mm and the height is 5mm to 15mm; The number of the branch channels (3) is 30 to 100, and the width of the branch channels (3) is 8 mm to 20 mm and the height is 2 mm to 6 mm; The diameters of the inlet (6) and the outlet (7) are both 15mm to 30mm.

6. A low flow resistance liquid cooling plate according to claim 1, characterized in that, The flow isolation zone (4) is provided with a plurality of mounting holes (5), which are spaced apart along the extension direction of the flow isolation zone (4), and the plurality of mounting holes (5) are all arranged to avoid the confluence channel (2) and the plurality of branch channels (3).

7. A low flow resistance liquid cooling plate according to claim 1, characterized in that, The plate (1) is made of aluminum alloy plate, stainless steel plate or copper alloy plate.

8. A low flow resistance liquid cooling plate according to claim 7, characterized in that, The confluence channel (2) and the branch channel (3) are formed by stamping and welding, roll forming, brazing, laser welding, extrusion forming or blow molding.

9. A secondary composite photothermal module, characterized in that, Including photovoltaic laminate (9), thermoplastic polyolefin film (8), and low flow resistance liquid cooling plate as described in any one of claims 1 to 8; The photovoltaic laminate (9) is a photovoltaic laminate (9) formed by a single lamination and encapsulation. The light-receiving surface of the photovoltaic laminate (9) is covered with a black light-absorbing coating. The multiple mounting holes (5) are used to avoid the current lead wires (11) of the photovoltaic laminate (9). The thermoplastic polyolefin film (8) is sandwiched between the back of the photovoltaic laminate (9) and the plate (1) of the low flow resistance liquid cooling plate, and the thickness of the thermoplastic polyolefin film (8) is 0.2mm to 0.5mm. The photovoltaic laminate (9), the thermoplastic polyolefin film (8), and the low flow resistance liquid cooling plate are laminated together to form an integrated structure. The thermoplastic polyolefin film (8) fills the interface gap between the photovoltaic laminate (9) and the low flow resistance liquid cooling plate and forms a continuous adhesive layer. It also includes a junction box (10) and a frame (12), wherein the junction box (10) is electrically connected to the current lead (11) of the photovoltaic laminate (9), and the frame (12) is a polyurethane frame and is disposed on the outer periphery of the photothermal component.

10. A method for preparing a secondary composite photothermal module, characterized in that, Includes the following steps: S1. Provides a photovoltaic laminate (9) formed by one-time lamination and encapsulation, a thermoplastic polyolefin film (8), and a low flow resistance liquid cooling plate with multiple parallel branch channels (3); S2. The low flow resistance liquid cooling plate is pretreated, the pretreatment including at least one of degreasing, cleaning, drying and surface activation treatment, and the low flow resistance liquid cooling plate is tested for air tightness. S3. The thermoplastic polyolefin film (8) is laid on the back of the photovoltaic laminate (9), and the low flow resistance liquid cooling plate is stacked on the side of the thermoplastic polyolefin film (8) away from the photovoltaic laminate (9). The mounting hole (5) on the low flow resistance liquid cooling plate is positioned to avoid the current lead (11) of the photovoltaic laminate (9) to form the laminate. S4. Perform a first composite treatment on the component to be laminated. Under vacuum conditions, heat and pressurize the component to be laminated for 10 min to 15 min at a temperature of 100℃~120℃ and a pressure of 50kPa~70kPa, so that the thermoplastic polyolefin film (8) softens and fills the interface gap between the back of the photovoltaic laminate (9) and the low flow resistance liquid cooling plate. S5. The laminated part after the first composite treatment is subjected to a second shaping treatment. Under the condition of maintaining pressure, it is subjected to pressure holding and cooling at a temperature of 40℃~60℃ and a pressure of 40kPa~60kPa for 10min~15min to shape the thermoplastic polyolefin film (8) and to form an integrated secondary composite photothermal component with the photovoltaic laminate (9), the thermoplastic polyolefin film (8) and the low flow resistance liquid cooling plate. S6. Cool the component after the second shaping process to room temperature, remove excess adhesive film from the edges, and check whether there is any interference between the mounting hole (5) and the current lead (11). Then install the junction box (10) and the frame (12). S7. The obtained secondary composite photovoltaic module is tested, and the test includes at least one of the following: appearance inspection, insulation withstand voltage test, grounding continuity test, airtightness test, flow resistance test, thermal cycling test, and photovoltaic electrical performance test.

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