Roof photovoltaic backboard vertical blowing cooling device

Abstract

The utility model discloses a vertical blowing cooling device for a roof photovoltaic backboard, and belongs to the technical field of photovoltaic industry. According to the utility model, the problem that the efficiency of converting light energy into electric energy by the photovoltaic backboard is reduced because the temperature of the existing photovoltaic backboard is increased is solved. A plurality of air supply through holes are evenly formed in the air supply plate, the air supply plate is supported through the air supply plate supports, the film barrier strips are evenly and fixedly connected to the lower portion of the air supply plate, one end of the boosting film is fixedly connected to one end of the air supply plate, and the transmission rope is connected between the other end of the boosting film and an output shaft of the motor. The boosting film is in lap joint with the multiple film barrier strips, and the position, between every two film barrier strips, of the boosting film is sleeved with a return plate strip. The air supply through holes in the air supply plate are matched with the air supply assembly to push air between the air supply plate and the air supply assembly upwards, so that the working temperature of the photovoltaic assembly is effectively reduced, and the photoelectric conversion efficiency of the photovoltaic assembly is improved.

Description

Technical Field

[0001] This utility model relates to a vertical air blowing cooling device for rooftop photovoltaic back panels, belonging to the field of solar photovoltaic back panels. Background Technology

[0002] The power generation principle of a photovoltaic backsheet is to directly convert light energy into electrical energy using the photoelectric effect of semiconductors, and the generated electrical energy is stored in the battery. A photovoltaic device mainly consists of three parts: a photovoltaic backsheet, a controller, and an inverter. The photovoltaic backsheet can directly absorb light energy and convert it into electrical energy. Therefore, the larger the area of ​​the photovoltaic backsheet, the more light energy it can absorb and the more electrical energy it can convert.

[0003] When a photovoltaic (PV) backsheet absorbs light energy, its light energy conversion efficiency is related to the light intensity. The greater the light intensity, the higher the conversion efficiency of the PV backsheet. However, the conversion efficiency is not positively correlated. Under high-intensity light, the temperature of the PV backsheet rises sharply. When the temperature of the PV backsheet is too high, the rate at which the PV backsheet absorbs light energy will decrease significantly, resulting in a reduction in the efficiency of the PV backsheet in converting light energy into electrical energy. Utility Model Content

[0004] This invention aims to solve the problem of reduced photoelectric conversion efficiency caused by excessively high temperature of solar photovoltaic back panels under high-intensity sunlight, and provides a vertical air-blowing cooling device for rooftop photovoltaic back panels.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0006] A vertical air-blowing cooling device for rooftop photovoltaic back panels includes an air supply plate, multiple air supply plate supports, and an air supply assembly. Multiple air supply holes are evenly distributed on the air supply plate, which is supported by the supports. The air supply assembly includes a motor, a transmission rope, a push-pull film, multiple return strips, and multiple film baffles. The film baffles are evenly fixed below the air supply plate. One end of the push-pull film is fixed to one end of the air supply plate, and the other end of the push-pull film is connected to the output shaft of the motor via the transmission rope. The push-pull film overlaps the multiple film baffles, and a return strip is fitted onto the push-pull film between every two film baffles.

[0007] Furthermore, there are two transmission ropes, which are respectively fixed to both sides of the other end of the booster membrane.

[0008] Furthermore, there are two motors, which rotate synchronously, and the two sides of the other end of the booster film are respectively connected to the output shafts of the two motors through two transmission ropes.

[0009] Furthermore, the air supply plate and the air supply holes within the unit area corresponding to each photovoltaic backsheet are arranged in three rows and five columns.

[0010] Furthermore, the booster film is always in an active state of rising or falling.

[0011] Furthermore, the range of motion of the booster film is between the bottom surface of the air supply plate and the upper surface of the roof.

[0012] Furthermore, the return strip has a rectangular ring structure and is slidably connected to the booster film.

[0013] Furthermore, there are four air supply panel supports, arranged symmetrically in pairs around the air supply panel.

[0014] Furthermore, the thin film baffle has an L-shaped structure, with the short side of the L-shaped structure fixed to the side of the air supply plate and the long side of the L-shaped structure located below the air supply plate.

[0015] Furthermore, the thickness of the air supply plate is 0.04m-0.08m, and the diameter of the air supply hole is 0.1m.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The vertical air-blowing cooling device for rooftop photovoltaic back panels utilizes the air supply holes on the air supply plate in conjunction with the air supply components to push the air between the air supply plate and the air supply components upward. As the air flows through the air supply holes, it forms a vortex ring that blows towards the photovoltaic back panel, increasing the convective heat transfer of the photovoltaic back panel, weakening the thermal boundary layer of the photovoltaic back panel, thereby effectively reducing the operating temperature of the photovoltaic back panel and improving the photoelectric conversion efficiency of the photovoltaic back panel. Attached Figure Description

[0018] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0019] Figure 1 A three-dimensional structural diagram of a vertical air-blowing cooling device for rooftop photovoltaic back panels;

[0020] Figure 2 Top view of a vertical air-blowing cooling device for rooftop photovoltaic back panels;

[0021] Figure 3 A schematic diagram showing the positional relationship between the vertical air-blowing cooling device for rooftop photovoltaic back panels and the photovoltaic back panels;

[0022] Figure 4 Temperature cloud map of the photovoltaic back panel before the implementation of the vertical air blowing cooling device for the rooftop photovoltaic back panel in the numerical simulation;

[0023] Figure 5This is a temperature cloud map of the photovoltaic back panel after implementing the vertical air blowing cooling device for the rooftop photovoltaic back panel in a numerical simulation.

[0024] In the diagram: 1. Air supply plate; 2. Air supply plate bracket; 3. Air supply through hole; 4. Motor; 5. Transmission rope; 6. Boosting film; 7. Return strip; 8. Film baffle; 9. Photovoltaic backsheet. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present utility model can be combined with each other, and the described embodiments are only some embodiments of the present utility model, not all embodiments.

[0026] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] See appendix Figure 1-3 This embodiment describes a vertical air-blowing cooling device for a rooftop photovoltaic backsheet, comprising an air supply plate 1, multiple air supply plate supports 2, and an air supply assembly. The air supply plate 1 has multiple evenly spaced air supply holes 3. The air supply plate 1 is supported by the multiple air supply plate supports 2. The air supply assembly includes a motor 4, a transmission rope 5, a propulsion film 6, multiple return strips 7, and multiple film baffles 8. The multiple film baffles 8 are evenly fixed below the air supply plate 1. One end of the propulsion film 6 is fixed to one end of the air supply plate 1, and the other end of the propulsion film 6 is connected to the output shaft of the motor 4 via the transmission rope 5. The propulsion film 6 overlaps the multiple film baffles 8, and a return strip 7 is fitted onto the propulsion film 6 between every two film baffles 8. Specifically, the vertical air-blowing cooling device for the rooftop photovoltaic backsheet is installed directly below the photovoltaic backsheet 9.

[0028] The vertical air-blowing cooling device for rooftop photovoltaic back panels connects the boosting film 6 to the air supply position via an air supply plate 1 and a film baffle 8. A motor 4 pulls the corresponding transmission ropes 5, gradually straightening the boosting film 6 from its natural hanging state. The transmission ropes keep the boosting film 6 in an upward state, pushing the air between the boosting film 6 and the air supply plate 1 into the air supply holes 3. As the air flows through the air supply holes 3, it forms a vortex ring that blows towards the photovoltaic back panel. A return strip 7 is fitted onto the boosting film, allowing it to descend at a uniform speed due to gravity. The boosting film then rises again via the motor and transmission ropes. This air supply component increases the convective heat transfer of the photovoltaic back panel 9, weakens the thermal boundary layer of the photovoltaic back panel 9, effectively reducing the operating temperature of the photovoltaic back panel 9 and improving its photoelectric conversion efficiency.

[0029] There are two drive ropes 5, which are respectively fixed to both sides of the other end of the boosting membrane 6. Specifically, the drive ropes 5 are connected to the other end of the boosting membrane 6 through stainless steel rings fixed on the boosting membrane 6. The two drive ropes 5 can reduce the tensile deformation of the boosting membrane 6 when it is in motion, and ensure the stability of the boosting membrane 6 when it is in motion.

[0030] There are two motors 4, which rotate synchronously. The other two ends of the boosting membrane 6 are connected to the output shafts of the two motors 4 by two transmission ropes 5. By pulling the boosting membrane 6 with the two synchronously rotating motors 4, the force on the boosting membrane 6 can be made even, avoiding the phenomenon of tearing of the boosting membrane 6 due to uneven force.

[0031] The air supply plate 1 and the air supply holes 3 within the unit area corresponding to each photovoltaic back panel 9 are arranged in three rows and five columns. By arranging the air supply holes 3 in three rows and five columns within the unit area, the air supply efficiency per unit area on the air supply plate 1 can be maximized, the efficiency of the vortex ring air supply can be improved, and thus the vertical air blowing cooling device for the roof photovoltaic back panel can achieve a better cooling effect.

[0032] The booster film 6 is always in a rising or falling motion. The booster film 6 is driven by the motor 4 and the transmission rope 5 to achieve up-and-down reciprocating motion, thereby blowing the air between the booster film 6 and the air supply plate 1 through the air supply hole 3 to form a vortex ring towards the photovoltaic back panel 9, improving the heat exchange efficiency of the photovoltaic back panel 9, and thus improving the photoelectric conversion efficiency of the photovoltaic back panel 9.

[0033] The range of motion of the booster film 6 is between the bottom surface of the air supply plate 1 and the upper surface of the roof. By adjusting the pulling degree of the booster film 6 by the motor 4 and the transmission rope 5, the range of rise and fall of the booster film 6 is controlled, avoiding contact between the booster film 6 and the lower surface of the air supply plate 1, thereby ensuring the continuous operation of the booster film 6, improving the air supply efficiency of the booster film 6, and ensuring the overall cooling effect of the vertical air blowing cooling device for the roof photovoltaic back panel.

[0034] The return strip 7 is a rectangular ring structure and is slidably connected to the booster membrane 6. The rectangular ring structure of the return strip, when fitted onto the booster membrane, allows the booster membrane to descend at a uniform speed under the gravity of the return strip.

[0035] There are four air supply panel supports 2, arranged symmetrically in pairs around the air supply panel 1. This design further improves the overall stability of the vertical air blowing cooling device for the rooftop photovoltaic back panel.

[0036] The thin-film baffle 8 has an L-shaped structure. The short side of the L-shaped structure is fixed to the side of the air supply plate 1, and the long side of the L-shaped structure is located below the air supply plate 1. The long side of the L-shaped structure contacts the lower surface of the booster film 6. The thin-film baffle 8 divides the booster film 6 into multiple small air supply units, thereby reducing the range of motion of the booster film 6. At the same time, it can also prevent the air supply volume of the booster film 6 from decreasing too much from the center to both ends, which would result in poor cooling effect at the edge of the photovoltaic backsheet 9.

[0037] The thickness of the air supply plate 1 is 0.04m-0.08m, and the diameter of the air supply hole 3 is 0.1m. Specifically, the application scenario of the roof photovoltaic back panel vertical air blowing cooling device is the roof. Considering the load-bearing capacity of the roof, setting the thickness of the air supply plate 1 to 0.04m-0.08m and the diameter of the air supply hole 3 to 0.1m are conducive to achieving overall weight reduction of the roof photovoltaic back panel vertical air blowing cooling device, ensuring that it is within the load-bearing range of the roof.

[0038] The total length of the booster film 6 is the same as the length of the air supply plate 1. Specifically, the length of the booster film 6 should be such that it does not contact the roof at the lowest point of its operating range, and does not contact the lower surface of the air supply plate 1 at the highest point of its operating range, thereby ensuring that the booster film 6 achieves the maximum air supply volume within its operating range.

[0039] The working principle of the vertical air blowing cooling device for rooftop photovoltaic back panels of the present invention is as follows:

[0040] A vertical air-blowing cooling device is installed below the rooftop photovoltaic back panel. In the rising state, two motors 4 rotate synchronously, pulling the corresponding transmission ropes 5 to gradually straighten the booster film 6 from its natural hanging state. During the rising process of the booster film 6, the air between the booster film 6 and the air supply plate 1 forms a vortex ring through the air supply hole 3 and blows it toward the photovoltaic back panel 9. When the booster film 6 between every two film baffles 8 is straightened, the motor 4 stops pulling the transmission rope 5. At the same time, the booster film 6 enters the falling state, the output shaft of the motor loosens the transmission rope, and the booster film 6 descends at a constant speed under the gravity of the return plate 7. When the transmission rope 5 wound on the output shaft of the motor is completely loosened, the booster film reaches the lowest point of the falling state and does not touch the roof. The booster film enters the rising state again through the pulling of the motor and the transmission rope.

[0041] To verify the cooling effect of this device on the rooftop photovoltaic backsheet, a numerical model per unit area was established based on actual usage conditions. The photovoltaic backsheet was set to a type II thermal boundary condition, and the heat flux density was set to 100 W / m². 2 A vertical air-blowing cooling device is installed at the lower end of the photovoltaic backsheet. The air supply plate has a thickness of 0.07m, and the distance between the air supply plate and the lower surface of the photovoltaic backsheet is set to 0.06m. In this invention, the vertical air-blowing cooling device for the rooftop photovoltaic backsheet is placed in the center of the computational domain, which is set to a windless condition with an ambient temperature of 25℃.

[0042] The gas flow involved in this numerical model is a low-speed flow with a Mach number less than 0.3, so air can be considered an incompressible fluid. The turbulence model is calculated using the SST k-ω equation model. Based on the above assumptions, the time-mean governing equations of the k-ω turbulence mathematical model are obtained. The spatial inviscid term scheme uses a second-order upwind scheme, and the SIMPLE algorithm is used to solve the discrete equations. When the residuals of both the velocity and pressure terms are less than 10... -3 Meanwhile, the residual values ​​of temperature are all less than 10. -6 When the system of governing equations converges, the velocity and pressure distribution at each location within the computational domain can be obtained.

[0043] The final set of governing equations is shown below:

[0044] Continuity equation:

[0045]

[0046] Momentum equation:

[0047]

[0048] Energy equation:

[0049]

[0050] In the above formula, u is the airflow velocity; k is the turbulent pulsating kinetic energy; T is the indoor air temperature; μ is the laminar dynamic viscosity coefficient; μ t ρ is the turbulent dynamic viscosity coefficient; p is the air pressure; ρ is the air density; C p ρ is the specific heat capacity of air at constant pressure; q is the heat flux density; β is the coefficient of fluid volume expansion.

[0051] Simulation results are as follows Figure 4-5 As shown in the simulation results, the effect is as follows when the vertical airflow cooling device for the rooftop photovoltaic back panel of this invention is not installed: Figure 4 The entire surface area of ​​the photovoltaic back panel is darker in color, indicating a higher temperature. When the vertical airflow cooling device for the rooftop photovoltaic back panel of this invention is installed, the effect is as follows: Figure 5 The photovoltaic backsheet has a lower temperature, resulting in a higher convective heat transfer coefficient and a significant cooling effect. After adopting this invention, the average surface temperature of the photovoltaic backsheet decreased from 65.0℃ to 38.1℃, a cooling effect of approximately 41.4%, and the power generation increased by approximately 11.0%.

[0052] Obviously, the above-disclosed embodiments of the present invention are merely for illustrating the present invention. The embodiments do not exhaustively describe all details, nor do they limit the present invention to specific implementations. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. It is neither necessary nor possible to exhaustively describe all implementation methods here.

Claims

1. A vertical air-blowing cooling device for rooftop photovoltaic back panels, characterized in that: The utility model provides an air supply plate, a plurality of air supply plate supports and an air supply assembly, a plurality of air supply through holes (3) are uniformly arranged on the air supply plate (1), the air supply plate (1) is supported by a plurality of air supply plate supports (2), the air supply assembly comprises a motor (4), a transmission rope (5), a boosting film (6), a plurality of return plate strips (7) and a plurality of film blocking strips (8), the plurality of film blocking strips (8) are uniformly fixed below the air supply plate (1), one end of the boosting film (6) is fixed to one end of the air supply plate (1), the transmission rope (5) is connected between the other end of the boosting film (6) and the output shaft of the motor (4), the boosting film (6) is overlapped on the plurality of film blocking strips (8), and the return plate strip (7) is sleeved on the boosting film (6) between every two film blocking strips (8).

2. A vertical air-blowing cooling device for a roof photovoltaic backsheet according to claim 1, characterized in that: The transmission rope (5) is two, and the two transmission ropes (5) are fixed to the two sides of the other end of the boosting film (6) respectively.

3. The vertical air-blowing cooling device for a roof photovoltaic backsheet according to claim 2, characterized in that: The motor (4) is two, and the two motors (4) rotate synchronously, and the two sides of the other end of the boosting film (6) are connected with the output shafts of the two motors (4) through the two transmission ropes respectively.

4. The vertical air-blowing cooling device for a roof photovoltaic backsheet according to claim 1, characterized in that: The air supply through holes (3) in the unit area corresponding to the air supply plate (1) and each photovoltaic back plate (9) are arranged in three rows and five columns.

5. The vertical air blowing cooling device for the roof photovoltaic back sheet according to claim 1, characterized in that: The boosting film (6) always keeps an active state of rising or falling.

6. The vertical air blowing cooling device for the roof photovoltaic back sheet according to claim 1, characterized in that: The activity range of the boosting film (6) is between the bottom surface of the air supply plate (1) and the upper surface of the roof.

7. The vertical air-blowing cooling device for a roof photovoltaic backsheet according to claim 1, characterized in that: The return plate strip (7) is a rectangular ring structure, and the return plate strip (7) is slidably connected on the boosting film (6).

8. The vertical air blowing cooling device for the roof photovoltaic back sheet according to claim 1, characterized in that: The air supply plate support (2) is four, and two two symmetrical arrangements are arranged at the four positions of the air supply plate (1).

9. The vertical air blowing cooling device for the roof photovoltaic back sheet according to claim 1, characterized in that: The film blocking strip (8) is an L-shaped structure, the short side of the L-shaped structure is fixed to the side of the air supply plate (1), and the long side of the L-shaped structure is located below the air supply plate (1).

10. The vertical air-blowing cooling device for a roof photovoltaic backsheet according to claim 1, characterized in that: The thickness of the air supply plate (1) is 0.04m-0.08m, and the diameter of the air supply through hole (3) is 0.1m.

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