A force measuring device suitable for measuring the wave impact force on floating photovoltaic floats in the laboratory.

Abstract

A force-measuring device suitable for measuring the wave impact force on a floating photovoltaic buoy in a laboratory setting, relating to the field of marine photovoltaic power generation technology. It includes a perforated cover, stress ropes, plastic baffles, an elastic membrane structure, stress rope connection points, a vent valve, compressible fluid, and a fluid pressure sensor. The elastic membrane structure is semi-cylindrical, with its two semi-circular bases and rectangular face bonded to the plastic baffles and further reinforced by stress ropes. One side of the semi-circular bases on the two sides of the elastic membrane structure has a perforated cover, and the other side has a vent valve. The interior of the elastic membrane structure contains compressible fluid and includes a fluid pressure sensor for measuring pressure changes in the compressible fluid and transmitting the data to an external data acquisition device. The force-measuring device is connected to the photovoltaic buoy via stress ropes and reflects the average pressure generated by the wave force on the buoy by outputting changes in the internal fluid pressure.

Description

Technical Field

[0001] This invention relates to the field of marine floating photovoltaic power generation technology, and is a device for measuring the wave impact force on a floating photovoltaic buoy in a laboratory. Background Technology

[0002] In recent years, with my country's strong support for the development of new energy sources, the photovoltaic power generation sector has developed rapidly. However, onshore photovoltaic power generation requires a large amount of land, and the land available for photovoltaic development is gradually becoming increasingly scarce. Furthermore, while freshwater floating photovoltaic power generation has advantages such as high power generation efficiency and eco-friendliness, suitable water areas for development are limited, and my country's restrictions on freshwater floating photovoltaic development further restrict the area available for installation. Therefore, exploring the development of offshore floating photovoltaic power generation is imperative.

[0003] Unlike onshore and freshwater environments, marine environments are far more complex. Floating photovoltaic platforms, such as breakwaters and photovoltaic panels, are subject to wave impacts during their service life, especially when wave loads exceed design limits. Furthermore, wave impacts alter the structure's dynamic response, potentially leading to fatigue failure during its service life. To ensure the photovoltaic platform's wave resistance, prevent capsizing, and guarantee its safe and stable operation, effectively measuring the wave impact force on the platform is a crucial issue. Traditional methods for measuring hydrodynamic pressure often involve pressure sensors or transducers mounted on the structural surface. However, directly applying pressure sensors only provides single-point measurements and struggles to capture pressure across the entire measurement field. Summary of the Invention

[0004] This invention aims to provide a device suitable for measuring the wave impact force experienced by floating photovoltaic floats in a laboratory setting. The core of the device is a fully enclosed semi-cylindrical membrane structure, which houses a compressible fluid and a fluid pressure sensor. The membrane structure is connected to a plastic plate and fixed to an opening inside the float via stress ropes.

[0005] The first objective of this invention is to provide a force measuring device suitable for measuring the wave impact force on floating photovoltaic floats in a laboratory setting. The device includes a photovoltaic float array and a force measuring device installed inside the array. The force measuring device comprises a perforated cover, a stress rope, a plastic baffle, an elastic membrane structure, stress rope connection points, a venting valve, a compressible fluid, and a fluid pressure sensor. The elastic membrane structure is semi-cylindrical in shape, with its two semi-circular bases and rectangular surface bonded to the plastic baffle and further reinforced by the stress rope. One side of the semi-circular bases on both sides of the elastic membrane structure has a perforated cover, and the other side has a venting valve. The interior of the elastic membrane structure contains a compressible fluid and is equipped with a fluid pressure sensor for measuring pressure changes in the compressible fluid and transmitting the data to an external data acquisition device.

[0006] Furthermore, the plastic baffle is a symmetrical baffle welded together from three parts: a rectangular plastic plate in the middle and rectangular prisms on both sides with their centers partially hollowed out. The area of ​​each of the three parts of the plastic baffle is larger than the area of ​​the elastic membrane structure and the part it is bonded to.

[0007] Furthermore, stress rope connection points are evenly distributed on both sides of the elastic membrane structure near the bottom surface, and stress rope channels are provided at the corresponding positions of the plastic baffle.

[0008] Furthermore, a semi-circular opening is provided on one side of the connection between the elastic membrane structure and the plastic baffle for inserting and removing the fluid pressure sensor. The opening is provided with a perforated cover for sealing the device, and the perforated cover has a channel for optical fiber to pass through. The fluid pressure sensor is connected to the data acquisition instrument via optical fiber.

[0009] Furthermore, a hexagonal opening is provided on the other side of the connector between the elastic membrane structure and the plastic baffle for installing a flushing valve.

[0010] Furthermore, the fluid pressure sensor is an optical fiber fluid pressure sensor based on an FP resonant cavity, which consists of an optical fiber, an optical fiber core, and a MEMS chip. The MEMS chip includes a silicon substrate layer and a silicon nitride layer, wherein the silicon nitride layer and the bottom of the optical fiber core form an FP resonant cavity.

[0011] A second objective of this invention is to provide a method for measuring the wave impact force on a floating photovoltaic float, achieved through the force measuring device described above:

[0012] The force measuring device is connected to an external data acquisition instrument via optical fiber and is fixed inside the photovoltaic floating block array. The floating block array is fixed to the anchor blocks by anchor chains. Waves crashing against the bottom of the floating block array act entirely on the force measuring device in the corresponding area. The elastic membrane structure deforms under stress, generating volumetric strain, which in turn compresses the internal compressible fluid. The internal compressible fluid pressure rises as a result, and is output to the data acquisition instrument via a fluid pressure sensor. The average pressure P generated by the wave impact force on the platform is calculated using the following formula.

[0013] S = Πrh;

[0014] P = F / S;

[0015] Where S is the force-bearing area of ​​the elastic membrane of the force measuring device, r is the radius of the semicircle at the bottom of the elastic membrane structure, h is the side height of the elastic membrane structure, and F is the magnitude of the force reflected by the wave impact.

[0016] The beneficial effects of this invention are:

[0017] A force-measuring device for measuring the wave impact force on a floating photovoltaic buoy in a laboratory employs an elastic membrane to withstand wave impacts within a certain range. The measurement results reflect the combined effect of wave forces within the device's range, overcoming the limitation of direct pressure sensors providing only single-point measurements. The connection between plastic baffles and the elastic membrane offers several advantages: First, it fixes the position of the elastic membrane structure, more accurately converting the wave impact force into the membrane's volumetric strain, and further into changes in the internal fluid pressure. This addresses the issue of significant shape deformation of the membrane structure after impact, which affects internal fluid pressure changes. Second, the plastic plates isolate the elastic membrane structure from liquid pressure outside the wave direction, resulting in more accurate measurements. Third, it acts as a buffer to some extent, enhancing the overall structure's functionality and ensuring longer, more efficient, and stable operation. Fourth, the partially hollowed-out centers of the two plastic plates allow for the inclusion of a small amount of seawater during measurement. When the internal fluid density of the elastic membrane structure is less than that of seawater, this reduces buoyancy, lessens the burden on the stress ropes, and improves the device's aesthetics. Attached Figure Description

[0018] Figure 1 A force measuring device suitable for measuring the wave impact force on floating photovoltaic floats in the laboratory—top view of the overall structure;

[0019] Figure 2 A force measuring device suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory – front view of the force measuring device;

[0020] Figure 3 A force measuring device suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory - side view of the force measuring device;

[0021] Figure 4 A force measuring device suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory—side sectional view of the force measuring device;

[0022] Figure 5A side cross-sectional view of a force measuring device—a fluid pressure sensor—suitable for measuring wave impact forces on floating photovoltaic floats in a laboratory setting;

[0023] In the diagram: 1. Force measuring device; 2. Optical fiber; 3. Float array; 4. Anchor chain; 5. Anchor block; 6. Perforated cover; 7. Stress rope; 8. Plastic baffle; 9. Elastic membrane structure; 10. Stress rope connection point; 11. Flushing valve; 12. Compressible fluid; 13. Fluid pressure sensor; 14. Optical fiber core; 15. MEMS chip; 16. FP resonant cavity; 17. Silicon substrate; 18. Silicon nitride layer. Detailed Implementation

[0024] The technical solutions in this application will be clearly and completely described below with reference to the accompanying drawings:

[0025] See appendix Figure 1-3 The force measuring device 1 of this invention is installed inside a photovoltaic float array 3 in a laboratory. It mainly consists of a perforated cover 6, a stress rope 7, a plastic baffle 8, an elastic membrane structure 9, a stress rope connection point 10, a flushing valve 11, a compressible fluid 12, and a fluid pressure sensor 13. The two semi-circular bottom surfaces and the rectangular surface of the semi-cylindrical elastic membrane structure 9 are bonded to the plastic baffle 8 and further reinforced by the stress rope 7. The plastic baffle 8 is a symmetrical baffle welded from three parts: a rectangular plastic plate in the middle, and rectangular prisms with partially hollowed-out centers on both sides. The area of ​​each of the three parts of the plastic baffle 8 is larger than the area of ​​the elastic membrane structure 9 bonded to it, to prevent the influence of liquid pressure from other directions on the force measuring device.

[0026] See appendix Figure 4 The semi-circular opening on one side of the force measuring device 1 is mainly used for placing and removing the fluid pressure sensor 13, which can be replaced if the built-in fluid pressure sensor 13 malfunctions. When the device is in operation, the semi-circular opening is closed with the perforated cover 6, leaving only a small hole just large enough for the optical fiber 2 to pass through. The hexagonal vent valve 11 on the other side of the device is used to inject or release the compressible fluid 12 inside the device, and the pressure of the compressible fluid 12 can be appropriately adjusted.

[0027] See appendix Figure 5 The fluid pressure sensor 13 is an optical fiber fluid pressure sensor based on an FP resonant cavity, mainly composed of an optical fiber 2, an optical fiber core 14, and a MEMS chip 15. The MEMS chip 15 includes a silicon substrate layer 17 and a silicon nitride layer 18, wherein the silicon nitride layer 18 and the bottom of the optical fiber core 14 form an FP resonant cavity 16. When the pressure of the compressible fluid 12 inside the elastic membrane structure changes, the silicon nitride layer deforms under pressure, the distance of the FP resonant cavity changes, and thus the reflected light signal changes, thereby measuring the real-time change of the fluid pressure inside the device.

[0028] Both sides of the plastic baffle 8 are provided with multiple stress rope channels. One side of the stress rope 7 is welded to the floating block, and the other side is connected to the stress rope connection point 10 at the edge of the elastic membrane structure through the stress rope channel.

[0029] This invention provides a method for measuring the wave impact force on a floating photovoltaic buoy in a laboratory:

[0030] The force measuring device 1 outputs the change in internal fluid pressure when subjected to external force. The elastic membrane structure 9 is semi-cylindrical, and when external force is applied to various positions on its side, the internal fluid pressure rises uniformly. The correspondence between the compressive force and the pressure change of the compressible fluid 12 inside the device can be obtained by applying a force of a specific magnitude and range to the device. During the measurement process, the force measuring device 1 is connected to the data acquisition instrument (not shown in the figure) through the optical fiber 2 and is fixed inside the photovoltaic floating block array 3. The floating block array 3 is fixed together with the anchor block 5 by the anchor chain 4. The wave hitting the bottom of the floating block array 3 acts entirely on the force measuring device in the corresponding area. The elastic membrane structure 9 deforms under force, generating volumetric strain, which compresses the internal compressible fluid 12. The pressure of the internal compressible fluid 12 rises as a result, and is output to the data acquisition instrument through the fluid pressure sensor 13. Since the part of the device used to withstand the wave impact force is a standard semi-cylindrical side, the average pressure P generated by the wave impact force on the platform can be obtained. In the calculation, the deformation of the stress rope 7 connecting the float and the force measuring device can be ignored, and the pressure difference of the fluid inside the compressible fluid 12 can be ignored.

[0031] S = Πrh;

[0032] P = F / S;

[0033] Where S is the force-bearing area of ​​the elastic membrane of the force measuring device, r is the radius of the semicircle at the bottom of the elastic membrane structure, h is the side height of the elastic membrane structure, and F is the magnitude of the force reflected by the wave impact.

[0034] Based on the above-described technical concept and implementation methods of this invention, a force measuring device 1 is designed and installed inside a photovoltaic float array to form an integrated device for measuring the wave impact force on a floating photovoltaic float. The external force impact received by the elastic membrane structure 9 of the semi-cylindrical force measuring device causes a pressure change in the compressible fluid inside. This pressure change is collected by a fluid pressure sensor 13 located inside the elastic membrane structure 9 and output to an external mechanism, allowing real-time monitoring of the internal pressure change of the elastic membrane structure 9. This, in turn, yields the average pressure generated by the wave impact force on the platform, thus enabling monitoring of the wave impact force on the platform. It should be further noted that the above embodiments are merely for understanding the technical solution of this invention and are not intended to limit the scope of protection of this invention. Any obvious adjustments and modifications made to the above-described technical concept and solution of this invention should fall within the scope of protection of this invention.

Claims

1. A force measuring device suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory, characterized in that: The device includes a photovoltaic floating block array (3) and a force measuring device (1) installed inside the photovoltaic floating block array. The force measuring device (1) includes a perforated cover (6), a stress rope (7), a plastic baffle (8), an elastic membrane structure (9), a stress rope connection point (10), a flushing valve (11), a compressible fluid (12), and a fluid pressure sensor (13). The elastic membrane structure (9) is a semi-cylindrical shape. Its two semi-circular bottom surfaces and rectangular surface are bonded to the plastic baffle (8) and further reinforced by the stress rope (7). One side of the semi-circular bottom surface on both sides of the elastic membrane structure (9) is provided with a perforated cover (6), and the other side is provided with a flushing valve (11). The interior of the elastic membrane structure (9) is a compressible fluid (12) and is provided with a fluid pressure sensor (13) for measuring the pressure change of the compressible fluid (12) and transmitting it to the external acquisition instrument. The plastic baffle (8) is a symmetrical baffle made of three welded parts. The middle part of the plastic baffle (8) is a cuboid plastic plate that is bonded to the rectangular surface of the elastic membrane structure (9). The two sides of the plastic baffle (8) are cuboids with partially hollowed-out centers that are bonded to the semi-circular bottom surfaces of the elastic membrane structure (9) on both sides respectively. The area of ​​each of the three parts of the plastic baffle (8) is larger than the area of ​​the elastic membrane structure (9) bonded to it.

2. The force measuring device according to claim 1, suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory, is characterized in that: The elastic membrane structure (9) has stress rope connection points (10) evenly distributed on both sides near the bottom surface, and the plastic baffle (8) has a channel for stress rope (7) at the corresponding position.

3. The force measuring device according to claim 1, suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory, is characterized in that: A semi-circular opening is provided on one side of the connection between the elastic membrane structure (9) and the plastic baffle (8) for inserting and removing the fluid pressure sensor (13). A perforated cover (6) is provided at the opening for sealing the device. A channel for passing through the optical fiber (2) is left on the perforated cover (6). The fluid pressure sensor (13) is connected to the data acquisition instrument through the optical fiber (2).

4. The force measuring device according to claim 1, suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory, is characterized in that: The other side of the connector between the elastic membrane structure (9) and the plastic baffle (8) is provided with a hexagonal opening for installing the flushing valve (11).

5. The force measuring device according to claim 1, suitable for measuring the wave impact force on a floating photovoltaic float in a laboratory, is characterized in that: The fluid pressure sensor (13) is an optical fiber fluid pressure sensor based on FP resonant cavity, which consists of optical fiber (2), optical fiber core (14) and MEMS chip (15). The MEMS chip (15) includes a silicon substrate layer (17) and a silicon nitride layer (18), wherein the silicon nitride layer (18) and the bottom of the optical fiber core (14) form an FP resonant cavity (16).

6. A method for measuring the wave impact force on a floating photovoltaic buoy, characterized in that, This is achieved using the force measuring device according to any one of claims 1-5: The force measuring device (1) is connected to the external data acquisition instrument through the optical fiber (2) and is fixed inside the photovoltaic floating block array (3). The floating block array (3) is fixed together with the anchor block (5) through the anchor chain (4). The wave hitting the bottom of the floating block array (3) acts completely on the force measuring device in the corresponding area. The elastic membrane structure (9) is deformed by the force and generates volume strain, which causes the internal compressible fluid (12) to be squeezed. The pressure of the internal compressible fluid (12) rises as a result and is output to the data acquisition instrument through the fluid pressure sensor (13). The average pressure P generated by the wave impact force on the platform can be obtained using the following formula. S=Πrh; P=F / S; Where S is the force-bearing area of ​​the elastic membrane of the force measuring device, r is the radius of the semicircle at the bottom of the elastic membrane structure, h is the side height of the elastic membrane structure, and F is the magnitude of the force reflected by the wave impact.

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