Salt pond plastic straw mat collecting and releasing system and control method

Abstract

The invention discloses a salt pond plastic straw mat take-up and pay-off system and a control method. The system comprises a plastic straw mat take-up unit, a traction unit, a self-adaptive buoy chain and a control cabinet. The plastic straw mat winding unit is arranged at one end of the salt pond and comprises a floating winding shaft and a first driving mechanism. The traction unit comprises at least two traction winches arranged on the cofferdam and traction ropes of the traction winches. The head end of the self-adaptive buoy chain is connected with the traction rope, the tail end of the self-adaptive buoy chain is fixedly provided with the plastic straw mat, the self-adaptive buoy chain is formed by axially splicing a plurality of buoy single bodies and has preset deflection protruding in the traction direction when no external force exists, and inflation sealing cavities are formed in the single bodies. A tension sensing module, a position detection module and a controller are arranged in the control cabinet; and the controller is configured to control the traction winch and the first driving mechanism to operate synchronously during unfolding or folding, and dynamically adjust the output of the driving mechanism based on real-time tension feedback, so that the tension is maintained in a preset constant range. The stability, the reliability and the automation level of folding and unfolding operation are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of salt pond plastic sheeting deployment and recovery technology, and particularly relates to a salt pond plastic sheeting deployment and recovery system and control method. Background Technology

[0002] In salt pond production, plastic tarpaulins are widely used for rain protection during the rainy season and for insulation at night. Their deployment and retrieval efficiency and reliability directly affect the yield and quality of raw salt. Traditional deployment and retrieval of plastic tarpaulins mostly rely on manual operation or simple mechanical traction, which has problems such as high labor intensity, low efficiency, and poor safety.

[0003] In recent years, some mechanized deployment and retrieval devices have emerged, such as those using winches to pull the edges of the plastic sheeting, with floats assisting in deployment. However, these systems still have many shortcomings in actual operation: First, the plastic sheeting experiences high resistance and is prone to deviation when moving in water, leading to unstable deployment and retrieval, and even jamming or derailment; second, the traction force control is inaccurate, easily causing the plastic sheeting to tear or the float chain to deform; and third, they lack intelligent tension adjustment and position feedback mechanisms, making them unable to adapt to complex working conditions such as water level changes and wind interference.

[0004] Furthermore, existing pontoons mostly employ rigid connections or simple series connections, lacking adaptive bending capabilities. This makes it difficult to maintain a reasonable arc distribution during long-distance deployment and retrieval, further exacerbating motion resistance and system vibration. In terms of control systems, most equipment still uses open-loop or simple start-stop control, failing to achieve closed-loop tension adjustment and making it difficult to guarantee the stability and reliability of the deployment and retrieval process.

[0005] Therefore, there is an urgent need for a salt pond plastic tarpaulin deployment and take-up system that can achieve intelligent control, adaptive tension adjustment, reasonable structure, and stable operation, so as to improve the level of automation and operational safety. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a salt pond plastic sheeting deployment and take-up system and control method that can achieve intelligent control, adaptive tension adjustment, reasonable structure, and stable operation.

[0007] This invention is implemented as follows: a system for deploying and recovering plastic tarpaulins in a salt pond, characterized by comprising: a plastic tarpaulin winding unit, disposed at one end of the salt pond, including a floating reel for winding the plastic tarpaulin and a first drive mechanism for driving the floating reel to rotate; a traction unit, including at least two traction winches disposed on the salt pond cofferdam, with traction ropes wound on the traction winches; an adaptive float chain, with both ends connected to the free ends of the traction ropes and the back end fixedly connected to the free end of the plastic tarpaulin; the float chain is composed of multiple float units axially spliced ​​together by a splicing mechanism, and the float chain has a preset deflection protruding in the direction of plastic tarpaulin traction when there is no external force; each float unit is internally equipped with a filling... An airtight cavity; a control cabinet containing a control system, including: a tension sensing module for real-time detection of the tension of the traction rope; a position detection module for detecting the travel endpoint of the float chain or plastic sheet; and a controller electrically connected to the first drive mechanism, the traction winch, the tension sensing module, and the position detection module, respectively. The controller is configured to: control the traction winch to operate synchronously with the first drive mechanism during deployment or retraction operations, and dynamically adjust the output speed of the drive mechanism based on the real-time tension value fed back by the tension sensing module, so that the real-time tension value is maintained within a preset constant tension range.

[0008] More preferably, the target radius of curvature R of the preset deflection is determined by the total length L of the pontoon chain and the target sag h0, and is expressed by the formula R=L ² The formula (L / 2) is calculated using the formula (8×h0), which is derived from the geometric relationship that the pontoon chain is approximately an arc: ² ≈2Rh, where L is the total length of the pontoon chain in millimeters (mm); h0 is the sag of the pontoon chain under the deflection in millimeters (mm).

[0009] More preferably, the target elevation h0 is in the range of 200mm to 500mm.

[0010] More preferably, the cross-section of the float unit is streamlined, with a buoyancy surface mainly used to provide buoyancy in its width direction, and a front drag-reducing surface and a rear drag-reducing surface respectively formed on both sides of the width direction to reduce motion resistance; the front drag-reducing surface and the rear drag-reducing surface have concentric arcs.

[0011] More preferably, the float chain is provided with a plastic tarpaulin fixing part, which includes a bracket provided on the rear drag-reducing water-facing surface and a detachable fastener provided on the bracket for fixing and connecting the plastic tarpaulin.

[0012] More preferably, the splicing mechanism includes a transition section, a splicing flange, and a sealing end plate embedded inside the transition section. The sealing end plate is provided with an air nozzle with a one-way valve. The connection between the transition section and the end of the float unit is provided with a stiffening plate extending axially.

[0013] More preferably, the outer side of the float unit at both ends of the float chain is provided with shore guide wheels, and the rotation axis of the guide wheels is parallel to the cross-section of the float unit.

[0014] More preferably, the gas in the inflatable sealing cavity is an inert gas with a pressure maintained between 0.1 MPa and 0.15 MPa.

[0015] More preferably, the pontoon unit is welded from steel with a yield strength of not less than 235 MPa, and its outer surface is provided with an anti-corrosion coating.

[0016] More preferably, the position detection module includes a first position switch located at the end point of the plastic sheet unfolding and a second position switch located at the end point of the plastic sheet retraction.

[0017] Further preferably, the system also includes a track guiding unit, which includes a track set along the two sides of the salt pond, a hanging ring or slider movable along the track for constraining the edge of the plastic tarpaulin, and a track guide for assisting the edge of the plastic tarpaulin in guiding the track; the track guide is provided with a track guide tilt angle adjustment device.

[0018] Further preferably, the tilt angle adjustment device for the track entry device includes: a drive box; a hinged connecting rod, the lower end of which is hinged to the upper slide plate of the track entry device; and a linear transmission mechanism disposed in the drive box for converting the rotational motion of the drive device into the linear motion of the hinged connecting rod; the linear transmission mechanism is a gear and rack pair; when the drive device is running, the hinged connecting rod is driven to move through the transmission mechanism to adjust the tilt angle of the track entry device from the water surface.

[0019] In a further preferred embodiment, at the connection point between the adjacent float chain and the traction rope, a front-mounted anti-derailment traction ball is connected to the traction rope, and the anti-derailment traction ball is located within the track.

[0020] More preferably, the traction winch is equipped with a non-powered desalination device; the non-powered desalination device is located before the traction rope enters the drum, and has a channel for the traction rope to pass through; the non-powered desalination device is mounted on a guide shaft, the guide shaft is fixed to the winch frame and located in front of the drum, and the non-powered desalination device can slide freely along the axial direction of the guide shaft.

[0021] More preferably, the non-powered desalination device includes at least one desalination unit, the desalination unit having at least one U-shaped scraper with an upward opening, the two inner sidewalls of the U-shaped scraper forming the two sidewalls of the channel, and contacting the surface of the traction rope or having a gap of no more than 3 mm.

[0022] A further preferred embodiment includes an automatic drainage device for the plastic tarpaulin, used to remove rainwater deposited on the surface of the plastic tarpaulin. The automatic drainage device comprises: a drainage pipeline, including a siphonic water intake section, a flexible connecting section, and a drainage section connected in sequence, used to divert rainwater deposited on the plastic tarpaulin to a drainage ditch; a support system for supporting the drainage pipeline; a siphonic energy storage pipeline system, including an energy storage water intake pipe and a water pump, one end of the energy storage water intake pipe extending to the vicinity of the suction port of the siphonic water intake section, and the other end connected to the siphonic water intake section, the water pump being connected in series with the energy storage water intake pipe; and a first control valve, set in... The siphon water inlet is located at the water intake of the siphon water inlet section; a second control valve is located at the water outlet of the drainage section; during drainage, the first and second control valves are first closed, and then the water pump is started to fill the energy storage water inlet pipe with water, forming the siphon power; wherein, the siphon water inlet section is hinged to the support system via a hinge shaft, and the hinge shaft is connected to a drive motor for driving the siphon water inlet section to swing around the hinge shaft; the drive motor is configured to drive the siphon water inlet section to swing downward, so that its water intake presses down on the plastic sheet to form a water collection area; when swinging upward, it avoids the plastic sheet retraction path.

[0023] More preferably, the support system includes a first support and a second support, the first support being used to support the siphon water section and its drive motor, and the second support being used to fix the water pump.

[0024] More preferably, the first control valve is a normally closed check valve that automatically opens when the pressure in the siphon is lower than atmospheric pressure and automatically closes when the pressure is higher than atmospheric pressure; the second control valve is a controllable opening check valve that automatically opens when the pressure in the siphon reaches a set value and remains open under the action of water flow, and automatically closes after the water flow disappears.

[0025] More preferably, the water inlet of the siphon water intake section is provided with a barrier cage.

[0026] In a further preferred embodiment, the floating roll of the plastic covering winding unit is installed via a gantry frame, and the gantry frame is equipped with a top roller lifter for adjusting the floating height of the floating roll according to the water level of the brine pool.

[0027] More preferably, the controller is also connected to an emergency stop button and is configured to immediately cut off the power to all drive mechanisms and the traction winch when the user triggers the emergency stop button or the real-time tension value exceeds a safety threshold.

[0028] More preferably, the controller is a programmable logic controller (PLC), and the dynamic adjustment is achieved by the PLC controlling the frequency converter to change the motor speed of the first drive mechanism.

[0029] This invention also discloses a control method for the above-mentioned salt pond plastic sheeting release and take-up system, comprising the following steps: Deployment control steps: Receive deployment start signal; control the two traction winches to perform rope winding operation, and simultaneously control the first drive mechanism to drive the floating reel to perform unwinding operation; acquire the tension value fed back by the tension sensing module in real time; compare the tension value with the preset tension range, and dynamically adjust the output speed of the first drive mechanism through PID control algorithm to stabilize the tension within the preset range; When the position detection module detects that the float chain has reached the deployment endpoint, it controls all drive mechanisms and traction winches to stop. Retraction control steps: Receive a retraction start signal; control the first drive mechanism to drive the float shaft to perform a winding operation, and simultaneously control the two traction winches to perform a rope release operation; acquire the tension value fed back by the tension sensing module in real time; compare the tension value with a preset tension range, and dynamically adjust the output speed of the first drive mechanism through a PID control algorithm to stabilize the tension within the preset range; when the position detection module detects that the float chain has reached the retraction endpoint, control all drive mechanisms and traction winches to stop; wherein, the deployment start signal or retraction start signal is triggered by the operator with one click through a local touch screen or remote control, or is automatically generated by the system after receiving an external weather warning signal.

[0030] More preferably, in the deployment control step, the minimum value of the radial tension F is determined by calculating using the following formula: F≥2×M0 / L, Where M0 is the initial bending moment required to maintain the preset arc shape, and L is the total length of the pontoon chain; The initial bending moment M0 is determined by the following formula: M0 = E × I / R, Where E is the elastic modulus of the pontoon chain material, I is the overall cross-sectional moment of inertia of the pontoon chain, and R is the target radius of curvature; The cross-section of a single pontoon section is simplified to a rectangle, and its moment of inertia I 单 =(b×h ³ ) / 12, where b is the width and h is the height; The total moment of inertia I of the N pontoons 总 =N×I 单 N represents the number of individual pontoons, and N is greater than or equal to 1.

[0031] More preferably, after applying the radial tension F, the remaining sag (h) of the pontoon chain is predicted or verified using the following formula. ' ):h ' =h0×(1-(F×L / 2) / M0), where h0 is the target sag and M0 is the initial bending moment required to maintain the preset arc; during the control process, the predicted remaining sag h' is used as an auxiliary judgment basis: when h'≤1mm, it is considered that the float chain has reached the expected control target of almost straightening.

[0032] The advantages and technical effects of this invention are as follows: The specific technical effects of this invention are reflected in: Stable and reliable operation: The combination of constant tension control and low-resistance float chain design greatly reduces the risk of plastic sheet damage and system failure rate.

[0033] High degree of automation and intelligence: It realizes multi-mode intelligent control from one-button start and stop to automatic response based on weather conditions, which significantly reduces labor intensity.

[0034] Strong environmental adaptability: In response to harsh working conditions such as high corrosion in salt ponds, water level changes, and variable climate, comprehensive optimization has been carried out in terms of materials, structure, sealing, and protection, resulting in a significant improvement in equipment durability.

[0035] Convenient and efficient maintenance: The modular design and the introduction of auxiliary mechanisms such as self-cleaning and anti-derailment reduce the difficulty and frequency of daily maintenance.

[0036] Energy efficient: Streamlined design and precise control reduce unnecessary work, improve deployment and take-off efficiency, and reduce energy consumption.

[0037] This invention comprehensively improves the safety, reliability, efficiency, and automation level of the operation of storing and storing plastic tarpaulins in salt ponds, and has significant practical value and prospects for promotion. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a logic block diagram of the control cabinet of the present invention; Figure 3 This is a schematic diagram of the overall structure of the float chain of the present invention; Figure 4 yes Figure 3 Top view; Figure 5 yes Figure 3 Sectional view of AA; Figure 6 This is a schematic diagram of the individual float structure located at both ends of the float chain; Figure 7 This is a schematic diagram of the single-unit structure of the float located in the middle of the float chain; Figure 8This is a schematic diagram of the end splicing mechanism of the float unit; Figure 9 This is a schematic diagram of the internal structure of a single pontoon unit; Figure 10 This is a schematic diagram of the plastic tarpaulin connection structure; Figure 11 This is a schematic diagram of the orbital guidance unit structure; Figure 12 This is a three-dimensional structural diagram of the installation of the rail entry tilting lift; Figure 13 and Figure 14 This is a schematic diagram of the three-dimensional structure of the rail entry tilting lift without the drive box. Figure 15 This is a schematic diagram of a non-powered desalination unit. Figure 16 This is a schematic diagram of the installation structure of a non-powered desalination unit; Figure 17 This is the front view of the automatic drainage device for plastic tarpaulins; Figure 18 yes Figure 17 Top view; Figure 19 yes Figure 18 BB section view; Figure 20 yes Figure 17 A schematic diagram of the three-dimensional structure; Figure 21 This is a structural diagram showing the structure in the state of avoiding the plastic sheeting; Figure 22 This is the control principle diagram of the automatic drainage device for plastic tarpaulins.

[0039] In the diagram: 100, Plastic covering winding unit; 101, Floating roll; 102, First drive mechanism (M3); 103, Gantry frame; 104, Top roller lifter; 200. Traction unit; 201. Traction winch; 2011. Drum; 202. Traction rope; 203. Non-powered desalination unit; 2031. Channel; 2032. U-shaped scraper; 2033. Guide shaft; 2034. Connecting pipe; 300. Adaptive buoy chain; 301. Buoy unit; 301a. Front drag-reducing upstream surface; 301b. Rear drag-reducing upstream surface; 3011. Inflatable sealing cavity; 302. Splicing mechanism; 3021. Transition section; 3022. Splicing flange; 3023. Sealing end plate; 3023a. Air nozzle; 3024. Rib plate; 303. Plastic tarpaulin fixing part; 3031. Bracket; 3032. Detachable fastener; 304. Preset deflection; 305. Shore guide wheel; 400. Rail entry guide unit; 41. Suspension component; 42. Rail entry tilting lifter; 421. Drive box; 422. Hinge link; 423. Gear; 424. Rack; 425. Guide wheel; 43. Rail entry guide mechanism; 431. Upper slide plate of rail entry; 432. Lower slide plate of rail entry; 433. Guide rail; 44. Manual crank handle; 45. Drive motor; 46. Reducer; 47. Joint bearing assembly; 48. Anti-derailment traction ball.

[0040] 500. Control cabinet; 600, Plastic tarpaulin; 601, Hanging ring; 700. Salt Lake Cofferdam.

[0041] 800. Automatic drainage device for plastic tarpaulin; 81. Siphon suction section; 81-1. Suction port; 82. Flexible connection section; 83. Drainage section; 83-1. Drainage port; 84. Hinge shaft; 85. First support; 86. Drive motor; 87. Second support; 88. Energy storage water pipe; 89. Water pump; 810. First control valve; 811. Second control valve; 812. Barrier cage; 812-1. Upper ring plate; 812-2. Lower ring plate; 812-3. Spokes; 812-4. Support rod. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] Please see Figures 1 to 10A system for deploying and recovering plastic tarpaulins in a salt pond includes a core component: a plastic tarpaulin winding unit 100, located at one end of the salt pond, comprising a floating shaft 101 for winding the plastic tarpaulin 600 and a first drive mechanism 102 for driving the floating shaft 101 to rotate; a traction unit 200, comprising at least two traction winches 201 mounted on a salt pond cofferdam 700, with traction ropes 202 wound around the traction winches 201; an adaptive float chain 300, with both ends connected to the free ends of the traction ropes 202 and its back end fixedly connected to the free end of the plastic tarpaulin 600; the float chain 300 is formed by axially splicing multiple float units 301 through a splicing mechanism 302, and the float chain 300 has a preset deflection 304 protruding in the direction of plastic tarpaulin traction when there is no external force; each float unit 301 has an internal airtight seal. A sealed cavity 3011; a control cabinet 500, which houses a control system including: a tension sensing module 501 for real-time detection of the tension of the traction rope 202; a position detection module 502 for detecting the stroke endpoint of the float chain 300 or the plastic cover 600; and a controller 503 electrically connected to the first drive mechanism 102, the traction winch 201, the tension sensing module 501, and the position detection module 502, respectively. The controller 503 is configured to: control the traction winch 201 to operate synchronously with the first drive mechanism 102 during deployment or retraction operations, and dynamically adjust the output of the drive mechanism based on the real-time tension value fed back by the tension sensing module 501, so that the real-time tension value is maintained within a preset constant tension range. This solution addresses issues such as plastic sheet tearing, float chain deformation, and operational jamming caused by inaccurate tension control in traditional deployment and retrieval systems. Through closed-loop tension control, smooth and adaptive operation is achieved during deployment and retrieval, significantly reducing the failure rate and damage to the plastic sheet. The pre-set deflection design of the adaptive float chain allows it to naturally form a favorable arc in the water, effectively reducing motion resistance and improving the reliability and efficiency of the system, laying the foundation for automated and intelligent control.

[0044] Based on the geometric relationship that the pontoon chain can be approximated as a circular arc under a small deflection (sagittal height h0), the target radius of curvature R of the preset deflection is determined by the total length L of the pontoon chain and the target sagittal height h0, and is expressed by the formula R=L ² The formula (L / 2) is calculated using the formula (8×h0), which is derived from the geometric relationship that the pontoon chain is approximately an arc: ² ≈2Rh 0，Where L is the total length of the pontoon chain, in millimeters (mm); h0 is the sag of the pontoon chain under the stated deflection, in millimeters (mm). This provides a quantitative basis for the pre-designed arc shape of the pontoon chain, ensuring the scientific nature and consistency of its manufacturing and assembly. Through precise mathematical calculations, the pontoon chain achieves an optimal force distribution in the water, further guaranteeing smooth traction and low resistance, and avoiding additional energy consumption and mechanical wear caused by improper arc shape.

[0045] Further optimized, the target sag h0 is limited to a range of 200mm to 500mm. This range is the optimal interval derived from extensive practical experience. Within this range, the sag ensures that the float chain has sufficient flexibility to adapt to changes in water waves and traction, while avoiding excessive bending that would increase winding difficulty or interfere with the track. This achieves an optimal balance between flexibility and rigidity, ensuring the system's versatility and stability across different salt pan sizes.

[0046] Further preferably, the cross-section of the float unit 301 is streamlined, with a buoyancy surface formed in its width direction primarily for providing buoyancy, and a front drag-reducing surface 301a and a rear drag-reducing surface 301b formed on both sides of its width direction to reduce motion drag; the front drag-reducing surface and the rear drag-reducing surface have concentric arcs. A traction rope connection part 306 is provided on the front drag-reducing surface 301a side for fixing and connecting the traction rope.

[0047] The streamlined design significantly reduces fluid resistance when the float chain moves in water. The defined buoyancy surface ensures sufficient support, while the specially designed upwind surface smoothly separates and merges water flows, reducing eddies and turbulence. This significantly reduces traction energy consumption, increases operating speed, and mitigates long-cycle hydraulic impacts on the float structure, extending its service life.

[0048] More preferably, a plastic cover fixing part 303 is provided on the float chain 300. The plastic cover fixing part 303 includes a bracket 3031 provided on the rear drag-reducing water-facing surface and a detachable fastener 3032 provided on the bracket 3031 for fixing and connecting the plastic cover 600.

[0049] By positioning the plastic tarpaulin's fixing points at the rear of the streamlined body, the flow of water is prevented from being disturbed by the fixing components, maintaining the overall low-resistance characteristics. The design of the bracket and detachable fasteners makes the installation, replacement, and maintenance of the plastic tarpaulin more convenient and secure, improving the maintainability and operational efficiency of the equipment.

[0050] A further preferred embodiment describes the structure of the splicing mechanism 302, which includes a transition section 3021, a splicing flange 3022, and a sealing end plate 3023 embedded inside the transition section 3021. The sealing end plate 3023 is provided with a gas nozzle 3023a with a one-way valve. The connection between the transition section 3021 and the end of the float unit 301 is provided with a stiffening plate 3024 extending axially.

[0051] This splicing structure not only achieves reliable mechanical connection between the individual pontoons, but also ensures the independent sealing of the inflation chamber of each pontoon unit and convenient inflation function through sealing end plates and air nozzles. The design of the stiffening plates enhances the structural strength and resistance to bending fatigue at the connection points, ensuring the integrity and safety of the pontoon chain under long-term use.

[0052] Further preferably, the outer sides of the float units 301 at both ends of the float chain 300 are provided with shore guide wheels 305, the rotation axis of the guide wheels 305 being parallel to the cross-section of the float unit 301. The guide wheels effectively guide the float chain to smoothly turn at the pool edge, reducing rigid friction and collision between the chain end and the pool wall, preventing the float chain from jamming or wearing down. The specific axial direction ensures that the guide wheels can roll in the direction of movement of the float chain, further reducing local resistance and protecting the equipment.

[0053] Further preferably, the gas within the inflatable sealing cavity 3011 is an inert gas with a pressure maintained between 0.1 MPa and 0.15 MPa. Using an inert gas such as argon prevents oxidation and corrosion of the internal metal components of the pontoon, extending the lifespan of core components. This precise pressure range provides sufficient buoyancy to support the plastic sheeting while avoiding potential risks to the pontoon welds and structure from excessive pressure, ensuring long-term safety and reliability.

[0054] Further preferably, the pontoon unit 301 is welded from steel with a yield strength of not less than 235 MPa, and its outer surface is provided with an anti-corrosion coating. Optional materials include, but are not limited to, Q345, Q355, Q390, Q420, or Q460 steel plates; in this embodiment, Q345 is preferred. This ensures that the pontoon unit has sufficient mechanical strength to withstand traction, water pressure, and its own weight. The anti-corrosion coating on the outer surface effectively resists the strong corrosion of the high chloride ion environment of the brine pool, significantly improving the durability of the pontoon chain under harsh working conditions and reducing maintenance costs and frequency.

[0055] More preferably, the position detection module includes a first position switch located at the end point of the plastic sheet unfolding and a second position switch located at the end point of the plastic sheet retraction. Reliable end-point position detection is achieved using simple physical switches, resulting in low cost and strong anti-interference capabilities. It can accurately determine whether the unfolding or retraction action is complete, thereby triggering the controller to stop operation, preventing breakage or damage caused by over-limit operation of the equipment, and improving the automation and safety of the system.

[0056] For further recommendations, please refer to [link / reference]. Figures 1 to 14 The system also includes an entry guide unit 400, which includes a guide rail 433 set along the cofferdams 700 on both sides of the salt pond, a lifting ring 601 or slider that can move along the guide rail 433 to constrain the edge of the plastic mat 600, and an entry guide mechanism 43 for assisting the edge of the plastic mat 600 to enter the guide rail; the entry guide mechanism 43 is provided with an entry device tilt angle adjustment device.

[0057] This unit effectively constrains the edges of the plastic tarpaulin, preventing it from deviating, wrinkling, or derailing during deployment and retraction. The track entry device and its angle adjustment mechanism ensure that the edges of the plastic tarpaulin align smoothly and accurately with the track when it begins to move. It is a key auxiliary mechanism to ensure the normal operation of the system, greatly improving the success rate and automation level of the operation.

[0058] The plastic tarpaulin track entry tilt angle adjustment device includes a suspension component 41, a track entry tilt lifter 42, and a track entry guide mechanism 43. The suspension component 41 is fixed to the salt pond cofferdam support as an overall support. The track entry tilt lifter 42 is mounted on the suspension component 41, and its core is a linear transmission mechanism inside the drive box 421, which drives the hinged connecting rod 422 to move linearly. The end of the hinged connecting rod 422 is connected to the track entry upper slide plate 431 of the track entry guide mechanism 43. By controlling the linear movement of the hinged connecting rod 422, the entire track entry guide mechanism 43 can be driven to swing around its lower hinge point, thereby realizing the adjustment of the tilt angle.

[0059] This design establishes the basic architecture of the entire device. The suspended installation provides a stable foundation for height adjustment. Precise control of the hinged linkage's stroke via linear transmission converts rotational motion into changes in the rail guide angle, enabling remote and controllable adjustment. This structure separates the drive and execution components, resulting in a more rational layout and stronger resistance to salt spray corrosion, fundamentally solving the problem of difficult rail entry caused by water level changes in traditional fixed rail guides.

[0060] More preferably, the linear transmission mechanism is a rack and pinion pair, including a gear 423 rotatably disposed within the drive housing 421 and a rack 424 meshing with the gear 423. The rack 424 is connected to the upper end of the hinged connecting rod 422. Specifically, the linear transmission mechanism is defined as a rack and pinion pair. The gear 423 rotates within the drive housing 421, driving the meshing rack 424 to perform up-and-down linear motion. The rack 424 directly or indirectly serves as the upper section of the hinged connecting rod 422. The rack and pinion pair is a mature, efficient, and highly accurate linear motion mechanism. Its transmission ratio is constant, and the transmission is smooth, capable of converting the output torque of the drive device into linear thrust, thereby achieving fine-tuning of the tilt angle of the rail guide. This structure has a self-locking characteristic, reliably maintaining its position when the drive stops, preventing the rail guide from shifting due to its own weight or external forces, and ensuring the stability of the operation process.

[0061] More preferably, a guide wheel 425 is provided on the back of the rack 424, and the guide wheel 425 is mounted on the inner side wall of the drive housing 421. The guide wheel 425, mounted on the inner side wall of the drive housing 421, contacts the back of the rack or is embedded in the guide rail on its back. The guide wheel 425 and the back of the rack 424 form a sliding or rolling pair, which effectively constrains the movement trajectory of the rack 424, preventing it from swaying or twisting during transmission, and ensuring that it always moves smoothly in the vertical direction. This design significantly improves the stability of the transmission, reduces abnormal wear of the gears and racks, extends the service life of key transmission components, and reduces maintenance frequency.

[0062] Preferably, the input shaft of the gear 423 is connected to a drive device, which is either a manual crank handle 44 or a drive motor 45. This clarifies the rotation method of the drive gear 423, providing both manual and electric options. The manual crank handle 44 can be directly connected to the input shaft, while the drive motor 45 serves as the power source. This provides flexible power configuration options. The manual crank handle 44 mode is simple in structure, low in cost, and easy to maintain, suitable for small salt fields or as a backup drive method. The drive motor 45 mode enables electric operation, laying the foundation for remote control, automated integration, and linkage with a central control system, meeting the needs of modern salt fields for efficient and intelligent operation.

[0063] When the driving device is a drive motor 45, the output end of the drive motor 45 is connected to the input shaft of the gear 423 via a reducer 46. In the electric drive scheme, a reducer 46 is added between the input shaft of the drive motor 45 and the gear 423. The reducer 46 can reduce the output speed of the drive motor 45 while increasing the output torque, enabling the system to output sufficient force to smoothly drive the rail inserter. This ensures sufficient power and stability during the adjustment process, avoids jamming or incomplete adjustment due to insufficient torque, and also provides overload protection for the motor, improving the reliability and durability of the electric drive mode.

[0064] More preferably, the upper and lower links of the hinged link 422 are connected by a joint bearing assembly 47. The hinged link 422 is designed as a segmented structure, with its upper link (which can be considered an extension of the rack 424) connected to the lower link via the joint bearing assembly 47. The joint bearing assembly 47 provides a spherical connection with multi-degree-of-freedom adjustment capabilities. It can compensate for minor asymmetry caused by installation errors, foundation settlement, or movement, avoiding harmful bending moments and ensuring that the force is always transmitted in the ideal direction. This greatly reduces structural internal stress, improves the adaptability and reliability of the entire transmission chain, and ensures smooth long-term operation of the mechanism.

[0065] In a further preferred embodiment, the guide mechanism 43 further includes a lower guide rail plate 432 for the guide rail device. Both the upper guide rail plate 431 and the lower guide rail plate 432 are connected to parallel guide rails 433, forming a track between the two guide rails for guiding the edge of the plastic tarpaulin. The structure of the double guide rails and parallel guide rails forms a robust and stable guiding channel, effectively constraining the edge of the plastic tarpaulin and preventing lateral shifting, wrinkling, or derailment during deployment and retraction. Changes in the angle of the upper guide rail plate 431 synchronously adjust the angle of the track inlet, ensuring that the plastic tarpaulin can be smoothly and accurately guided into the track at any working angle, which is crucial for the reliable operation of the entire deployment and retraction system.

[0066] A further preferred embodiment includes a pre-positioned anti-derailment traction ball 48 within the track; this pre-positioned anti-derailment traction ball is connected to the traction rope connected to the plastic sheeting. The anti-derailment traction ball 48, acting as a physical barrier with a diameter larger than the track clearance, always rolls within the track. "Pre-positioned" means that the anti-derailment traction ball 48 is already within the track before the plastic sheeting enters it. This effectively prevents the traction rope from jumping out of the track when the force direction changes abruptly or the system vibrates, fundamentally avoiding system downtime, plastic sheeting damage, and maintenance work caused by derailment, significantly improving the continuity and safety of system operation.

[0067] Working principle explanation The working principle of this invention is as follows: When the device is working, the operator provides power through the drive device (manual crank 44 or drive motor 45). If it is electric, the power of the motor 45 is amplified by the reducer 46 and then transmitted to the gear 423 to make it rotate. The rotation of the gear 423 drives the rack 424 meshing with it to make precise vertical linear motion. The linear motion of the rack 424 is transmitted to the end joint bearing assembly 47 through the connecting rod 422 (the upper part of which may be integral with the rack or rigidly connected). The joint bearing assembly 47 transmits the linear thrust to the upper slide plate 431 of the guide rail mechanism 43. Since the lower slide plate 432 of the guide rail is usually suspended from the pool wall, the entire guide rail mechanism 43 will swing around the joint bearing assembly 47 of the lower slide plate 432 as the fulcrum (i.e., the hinge point), thereby changing the inlet tilt angle of its upper guide rail 433. This angle adjustment allows the rail inlet to always adaptively align with the edge of the plastic sheeting that floats due to water level changes, ensuring smooth entry. The entire transmission process is ensured by the gear and rack pair and the guide wheel 425, and the deviation is compensated by the spherical bearing assembly 47, thereby achieving reliable and adaptive height and angle adjustment.

[0068] For further recommendations, please refer to [link / reference]. Figure 15 and Figure 16 The traction winch 201 is equipped with a non-powered desalination device 203. The non-powered desalination device 203 has a channel for the traction rope 202 to pass through and can move synchronously with the traction rope 202 as it is wound up and down, continuously scraping away salt crystals adhering to its surface during the rope's deployment and retraction. This automatically and continuously removes highly corrosive salt crystals adhering to the traction rope in the salt pond environment, preventing salt particles from accelerating rope wear and corrosion, and extending the rope's service life. The non-powered design means it operates autonomously based on rope movement, requiring no additional energy, making it energy-efficient and reliable.

[0069] The non-powered desalination device 203 is positioned before the traction rope 202 enters the drum 204 and has a channel 2031 through which the traction rope 202 passes. The non-powered desalination device 203 is mounted on a guide shaft 2033, which is fixed to the winch frame and located in front of the drum 2011. The non-powered desalination device 203 can slide freely along the axial direction of the guide shaft 2033.

[0070] This technical solution is the core innovation of this invention. By incorporating a non-powered desalting device that moves synchronously with the cable, it achieves online, automatic, and continuous removal of salt crystals from the surface of the traction rope during operation. This design fundamentally solves a series of problems caused by salt crystal accumulation, such as increased rope diameter and rope disorder, ensuring stable winch operation. Most importantly, the entire desalination process requires no additional power source, cleverly utilizing the movement of the traction rope itself. The structure is simple and reliable, achieving an optimal balance between high efficiency and high reliability, significantly reducing system energy consumption and maintenance costs.

[0071] More preferably, the non-powered desalting device 203 includes at least one desalting unit, the desalting unit having an upward-facing U-shaped scraper 2032, the two inner sidewalls of the U-shaped scraper 2032 forming the two sidewalls of the channel 2031, and contacting the surface of the traction rope 202 or having a gap of no more than 3mm.

[0072] This preferred embodiment specifies the key components of the desalination unit. It employs an upward-facing U-shaped scraper structure, which can wrap around the traction rope from both sides and below, resulting in a large scraping area and high desalination efficiency. Its upward-facing design facilitates installation and maintenance, while effectively catching and guiding the scraped salt particles. The design maintains contact with the traction rope surface or a gap of no more than 3mm (preferably 2mm), ensuring effective scraping while preventing excessive wear on the traction rope itself, achieving a good balance between efficient desalination and rope protection.

[0073] More preferably, the non-powered desalination device 203 includes two parallel U-shaped scrapers 2032, which are fixedly connected by a connecting pipe 2034 to form an integrated structure.

[0074] This preferred design employs a dual-scraper structure, providing double desalination protection. The first scraper removes most of the crystals, while the second scraper performs a fine scraping, ensuring thorough removal and improving desalination cleanliness. The integrated structure enhances the rigidity and stability of the entire desalter, preventing skewing or vibration during reciprocating motion and ensuring the neatness of the rope arrangement. The connecting pipe not only serves as a connector but also acts as a structural reinforcement, while its internal structure forms a temporary storage and transport channel for salt particles—a clever design.

[0075] More preferably, the U-shaped scraper 2032 and the connecting pipe 2034 are both made of corrosion-resistant aluminum alloy material.

[0076] This preferred solution addresses the long-term durability issue of the equipment in harsh salt field environments from a material perspective. Aluminum alloy itself possesses excellent resistance to salt spray corrosion, effectively resisting brine erosion and significantly extending the service life of the desalination unit. Simultaneously, its lightweight nature and low inertia ensure flexible response and synchronous movement of the desalination unit on the guide shaft. Furthermore, aluminum alloy offers advantages such as ease of processing and low cost, making it ideal for mass production and practical applications.

[0077] Please refer to the diagram. Figures 17 to 22 This salt pond plastic tarpaulin deployment and recovery system also includes an automatic plastic tarpaulin drainage device 800, used to remove rainwater deposited on the surface of the plastic tarpaulin. The automatic plastic tarpaulin drainage device is designed based on the siphon principle and is particularly suitable for rain protection scenarios of plastic tarpaulins in sun-dried salt ponds. The device mainly includes drainage pipes, a support system, a siphon energy storage pipe system, and a control system.

[0078] The drainage pipe is the core water guiding component, comprising a siphon suction section 81, a flexible connecting section 82, and a drainage section 83 connected in sequence. A support system supports the drainage pipe. The siphon suction section 81 is hinged to the first support 85 of the support system via a hinge shaft 84, which is connected to a drive motor 86. The drive motor 86 can be a stepper motor or a servo motor. After receiving a control signal, it can precisely drive the siphon suction section 81 to swing around the hinge shaft 84 within a certain angle range. When drainage is needed, the drive motor 86 drives the siphon suction section 81 to swing downwards, and its end suction port 81-1 gently presses against the plastic sheeting below, forming a locally recessed water-collecting area to effectively collect rainwater. The downward pressure of the siphon suction section 81 ensures that the plastic sheeting is not damaged. When drainage is finished or when the plastic sheeting needs to be raised or lowered, the drive motor 86 drives the siphon suction section 81 to swing upwards, avoiding the movement path of the plastic sheeting and preventing interference with the automated covering system.

[0079] This structure, through the cooperation of a drive motor and a hinge shaft, enables precise switching between the "working" and "avoiding" states of the drainage unit, replacing complex multi-link or robotic arm mechanisms, thus reducing manufacturing costs and control complexity. Compared to the "rolling of the pressure rollers" method, the swinging downward action provides gentler contact with the plastic sheeting, avoiding the risk of wear or breakage caused by rolling friction and localized stress concentration, thereby extending the service life of the plastic sheeting.

[0080] The support system also includes a second support 87 for fixing the water pump 89. The first support 85 and the second support 87 can be independently fixed to the salt pond embankment or solid ground to form a stable support structure.

[0081] The siphon energy storage pipeline system includes an energy storage inlet pipe 88 and a water pump 89 connected in series thereon. One end of the energy storage inlet pipe 88 extends into the water collection area, and the other end is connected to the siphon water intake section 81. Both the flexible connection section 82 and the energy storage inlet pipe 88 are made of rubber or plastic hoses, which have good flexibility. The flexible pipe connection allows the pipeline connection between the siphon water intake section 81 and the fixed drainage section 83 and the water pump 89 to remain unobstructed and undamaged when the siphon water intake section 81 swings, solving the problem of leakage or damage to rigid pipelines under swinging conditions, improving the reliability and service life of the device, and simplifying installation and maintenance.

[0082] A first control valve 810 is installed at the suction port 81-1 of the siphon suction section 81. In this embodiment, this valve is a normally closed one-way valve. A second control valve 811 is installed at the drain port 83-1 of the drainage section 83, and an air vent valve 813 is installed on the siphon suction section 81. In this embodiment, the air vent valve 813 is a controllable opening one-way valve with a preset mechanical spring pressure value or an integrated miniature pressure sensor. It automatically opens when the water pressure in the pipe reaches the set value P.

[0083] The valve control strategy and operation sequence of this design constitute a highly efficient and reliable siphon start-up scheme. By first closing both valves and then injecting water using a water pump, the water pressure and full-pipe flow conditions required for siphon start-up are quickly established within the closed pipeline. Compared to existing technologies that rely on complex multi-functional valves for venting and pressure grading regulation, this scheme features a simple valve structure and direct action logic, reducing system failure rate and ensuring the success rate and repeatability of siphon start-up in harsh field environments.

[0084] To optimize the design, a barrier cage 812 is provided around the water intake 81-1 of the siphon water intake section 81. This barrier cage 812 includes an upper ring plate 812-1 and a lower ring plate 812-2, wherein the outer diameter of the lower ring plate 812-2 is smaller than the outer diameter of the upper ring plate 812-1. The inner wall of the upper ring plate 812-1 is fixedly connected to the outer wall of the water intake 81-1 via several spokes 812-3. The lower ring plate 812-2 is connected to the upper ring plate 812-1 via several support rods 812-4.

[0085] The design of the barrier cage 812 is ingenious and practical. The upper and lower ring plate structure effectively prevents the plastic tarpaulin from adhering to or being sucked into the water inlet 81-1 due to siphon negative pressure or wind blowing, thus avoiding blockage of the drainage pipe and damage to the tarpaulin. The structure of the spokes 812-3 and support rods 812-4 ensures the barrier function while minimizing obstruction to water flow, ensuring drainage efficiency.

[0086] The above describes the structure of an automatic drainage device for plastic tarpaulins based on the siphon principle. The drive motor 86 and water pump 89 of the automatic drainage device are electrically connected to the controller. The controller interacts with a remote control center or mobile terminal through a built-in wireless communication module (such as 4G / 5G), receives instructions and uploads equipment status, realizing 24 / 7 unattended operation and remote intelligent control.

[0087] Summary of the working principle of this invention: Preparation stage: During rainfall, the salt pond is covered with plastic sheeting. The controller receives the drainage command (remote command / manual control / automatic activation based on water level monitoring), starts the drive motor 86, and drives the siphon suction section 81 to swing down, so that the barrier cage 812 at the suction port 81-1 lightly presses the plastic sheeting to form a water collection area.

[0088] Siphon start-up phase: The first control valve 810 and the second control valve 811 are closed, and the controller starts the water pump 89 to pump rainwater from the water collection area into the entire drainage pipeline through the energy storage water inlet pipe 88.

[0089] Drainage Stage: When the water pressure in the pipeline rises to the set opening pressure P of the second control valve 811, the second control valve 811 is opened, and the full pipe of water flows out at high speed from the drain outlet 83-1 under the action of gravity, instantly creating a negative pressure (siphon effect). This negative pressure causes the first control valve 810 to open automatically, while simultaneously shutting off the water pump 89. Thereafter, rainwater in the water collection area is continuously and automatically pumped away under the siphon effect, requiring no additional power.

[0090] Stop and Reset Phase: When rainfall stops and the water level in the collection area drops to expose the suction port 81-1, air enters the pipeline, disrupting the siphon and stopping drainage. The first control valve 810 and the second control valve 811 automatically reset and close. The controller drives the siphon suction section 81 to swing upwards to reset, completing the operation cycle.

[0091] Preferably, the float shaft 101 of the plastic tarpaulin winding unit 100 is mounted via a gantry frame 103. The gantry frame 103 is equipped with a top roller lifter 104, used to adjust the floating height of the float shaft 101 according to the brine pond water level. This allows the plastic tarpaulin winding point to float with changes in the brine pond water level, always maintaining the optimal water entry angle and tension direction, reducing additional stress and wear caused by improper angles on the plastic tarpaulin, and adapting to the actual working conditions of changing brine pond water levels.

[0092] More preferably, the controller 503 is also connected to an emergency stop button 504 and is configured to immediately cut off the power to all drive mechanisms and the traction winch 201 when the user triggers the emergency stop button 504 or the real-time tension value exceeds a safety threshold.

[0093] It provides dual safety protection through both hardware and software. In the event of human error or system malfunction such as a sudden increase in tension, it can instantly stop all operations, effectively preventing equipment damage and potential personal injury, and meets industrial equipment safety standards.

[0094] Further preferred, the preset constant tensile force range is defined as 40 kg to 60 kg, and the safety threshold is set at 100 kg. Specific and optimized control parameters, verified in practice and applicable to most salt pond conditions, are provided. This ensures that the tensile force control has a clear target and safety boundary, guaranteeing the effective execution of the control algorithm and the system's safety margin.

[0095] More preferably, the controller 503 is a programmable logic controller (PLC), and the dynamic adjustment is achieved by the PLC controlling the frequency converter to change the motor speed of the first drive mechanism 102.

[0096] The use of industrial-grade reliable PLCs and control components ensures the stability, accuracy, and anti-interference capability of the system control. Variable frequency speed regulation enables stepless smooth adjustment of tension, resulting in fast response and high control precision; this is the core technology for achieving intelligent closed-loop control.

[0097] This invention also relates to a control method for a salt pond plastic sheeting deployment and retrieval system, comprising the following steps: Deployment control step: receiving a deployment start signal; controlling the two traction winches 201 to perform rope winding operations, while simultaneously controlling the first drive mechanism 102 to drive the float shaft 101 to perform unwinding operations; acquiring the tension value fed back by the tension sensing module 501 in real time; comparing the tension value with a preset tension range, and dynamically adjusting the output speed of the first drive mechanism 102 through a PID control algorithm to stabilize the tension within the preset range; when the position detection module 502 detects that the float chain 300 has reached the deployment endpoint, controlling all drive mechanisms and traction winches 201 to stop; Retraction control step: receiving a retraction start signal; controlling the first drive mechanism 102 to drive the float chain 300 to perform unwinding operations. The reel 101 performs a winding operation, while simultaneously controlling the two traction winches 201 to perform rope unwinding operations. The tension value fed back by the tension sensing module 501 is acquired in real time. This tension value is compared with a preset tension range, and the output speed of the first drive mechanism 102 is dynamically adjusted using a PID control algorithm to stabilize the tension within the preset range. When the position detection module 502 detects that the float chain 300 has reached the retraction endpoint, it controls all drive mechanisms and traction winches 201 to stop. The unfolding or retraction start signal is triggered by the operator via a local touchscreen or remote control, or automatically generated by the system after receiving an external weather warning signal, providing flexible and diverse operating modes that balance the convenience of on-site operation with the advanced features of remote / automatic control. In particular, the function of linkage with weather warnings enables proactive protection based on weather changes, greatly improving the intelligence level and risk resistance of salt pond production.

[0098] The system's hardware advantages are translated into specific, repeatable, and reliable operational procedures. Through PID control algorithms, rapid and precise compensation and adjustment of tension deviations can be achieved, effectively suppressing external disturbances such as wind and water flow, ensuring constant tension and smooth operation throughout the entire deployment and recovery process. This is the core method for achieving automated and efficient operation.

[0099] In the deployment control step, the minimum value of the radial tension F is determined by the following formula: F≥2×M0 / L, Where M0 is the initial bending moment required to maintain the preset arc shape, and L is the total length of the pontoon chain; The initial bending moment M0 is determined by the following formula: M0 = E × I / R, Where E is the elastic modulus of the pontoon chain material, I is the overall cross-sectional moment of inertia of the pontoon chain, and R is the target radius of curvature; The cross-section of a single pontoon section is simplified to a rectangle, and its moment of inertia I 单 =(b×h ³) / 12, where b is the width and h is the height; The total moment of inertia I of the N pontoons 总 =N×I 单 N represents the number of individual pontoons, and N is greater than or equal to 1.

[0100] More preferably, after applying the radial tension F, the remaining sag (h) of the pontoon chain is predicted or verified using the following formula. ' ): h ' =h0×(1-(F×L / 2) / M0), where h0 is the target sag and M0 is the initial bending moment required to maintain the preset arc; during the control process, the predicted remaining sag h' is used as an auxiliary judgment basis: when h'≤1mm, it is considered that the float chain has reached the expected control target of almost straightening.

[0101] Example: This example uses a typical salt pond (56 meters wide) as an example to illustrate the implementation process of the arc control method of the present invention. The float chain is composed of 9 float units axially spliced ​​together by a splicing mechanism, with a total length L of 56 meters. The float units are welded from Q235 steel, with an elastic modulus E of 2.1 × 10⁻⁶. 11 Pa, with a streamlined cross-section, is filled with argon gas at a pressure of 0.12 MPa.

[0102] 1. Pre-set arc design First, based on the width of the salt pond and the dimensions of the plastic tarpaulin's take-up and drop-off rollers, the total length of the float chain is determined to be L = 56000 mm. To ensure that the float chain effectively conforms to the rollers when stationary and avoids interference with the central idler roller, a target sag h0 = 300 mm is set (approximately 20 mm greater than the top diameter of the idler roller). Then, the target radius of curvature R of the pre-set arc is calculated using the following formula: R=L 2 / (8×h0) Substituting the data, we get: R=56000 2 / 8×300=3136000000 / 2400≈1306666.67 mm=1306.67 m. This R value is the arc control benchmark when splicing and forming the pontoon chain.

[0103] By quantitatively calculating the target radius of curvature R, the design of the pre-set arc shape is elevated from empirical estimation to scientific quantification, ensuring the optimal match between the arc shape and the winding roller. This effectively reduces the swaying of the float chain in wind and waves when stationary, improves system stability, and avoids increased traction resistance or spatial interference problems caused by improper arc curvature, providing a precise benchmark for subsequent control steps.

[0104] 2. Traction Straightening Control When the plastic sheeting needs to be deployed, a radial tension F is applied to both ends of the pontoon chain. To determine the minimum required tension, the initial bending moment M0 required to maintain the pre-set arc shape must first be calculated. The overall moment of inertia I of the pontoon chain needs to be calculated and accumulated from the cross-sections of individual pontoons. The cross-section of a single pontoon is simplified to a rectangle (0.4m wide, 0.2m high), and its moment of inertia I... 单 =(b×h ³ ) / 12, where b is the width and h is the height; I 单 =0.4×0.2 3 / 12=2.67×10 -4 m.

[0105] The total moment of inertia I of the 9-section pontoons 总 =9×I 单 =2.4×10 -3 m The initial bending moment M0 is calculated as follows: M0=E×I 总 / R=2.1×10 11 ×2.4×10 －3 / 1306.67≈38500 The minimum required tension F is: F≥2×M0 / L=2×38500 / 56≈1375 N (approximately 140 kgf on one side) In actual operation, by applying a pulling force of F=140kgf by the traction winch, the float chain can be made to move from a preset arc shape to a straight shape.

[0106] The minimum required tension is precisely calculated using a formula, avoiding the blind operation of the traction process. Insufficient tension may prevent the float chain from fully deploying, affecting the plastic tarpaulin coverage; excessive tension can easily damage the structure or increase energy consumption. This step ensures an efficient and smooth traction process, significantly reducing operational risks and energy consumption, while protecting the float chain and plastic tarpaulin from excessive stress damage.

[0107] 3. Adaptive Reset Control After the plastic covering is completed, the radial tension F is released. Under the action of its own structural restoring force (including the elastic restoring force of the material and the gas pressure of the inflatable sealing cavity), the float chain automatically returns to the preset arc shape. This restoration process does not require external power and is achieved by the bending stiffness EI of the float chain and the preset arc shape memory effect.

[0108] The flexural stiffness EI is calculated using the following formula: Bending stiffness EI: Total resistance to bending (material hardness × shape advantage): EI=σ×I 总 =2.1×10 11 ×2.4×10-3 =5.04×10 7 ox rice 2 Where σ is the yield strength of Q235 steel.

[0109] Utilizing the inherent structural restoring force of the float chain to achieve automatic reset simplifies the system structure and reduces failure rate and maintenance costs. This step ensures that the float chain reliably returns to its initial arc after each operation, preparing it for the next winding operation. This improves the system's recycling efficiency and automation level, making it particularly suitable for frequent deployment and retrieval environments in salt ponds.

[0110] In the pre-designed arc shape step, the target radius of curvature R is determined by the formula R=L 2 The formula / (8×h0) is calculated and determined. This formula is derived from geometric approximation, is applicable to cases with small sagittal heights, is simple to calculate, and its accuracy meets engineering requirements. Using this simplified formula greatly reduces the computational complexity of arc design, making it easy for on-site engineers to apply quickly, while ensuring design accuracy and avoiding implementation difficulties caused by complex models.

[0111] In the traction straightening control step, the minimum radial tension F is determined by the formula F≥2×M0 / L. This formula clarifies the direct relationship between the tension and the structural parameters (length, bending stiffness) of the pontoon chain. This formula directly links tension control to the mechanical properties of the pontoon chain, making the operation based on evidence, improving the scientific nature and reliability of the control, and avoiding the uncertainty of operation based on experience.

[0112] The initial bending moment M0 is determined by the formula M0 = E × I / R. Here, E and I are inherent properties of the material and cross-section, and R is the design value. By introducing the material modulus and the moment of inertia of the cross-section, the calculation of the initial bending moment becomes more accurate, reflecting the bending resistance of the pontoon chain itself and providing accurate input parameters for tensile force calculation.

[0113] After applying a tensile force F, the formula h can be used to... ' =h0×(1-(F×L / 2) / M0)Predict the remaining sag h ' Substitute the data: h ' =0.3×(1-(1375×56 / 2) / 38500)≈0.3×(1-0.999)≈0.0003m=0.3mm. The calculation shows that the tension F is sufficient to almost completely straighten the pontoon chain (the remaining sag is negligible). This predictive formula allows for verification of the traction effect before operation, early detection of whether the tension is appropriate, achieving process control and predictable results, optimizing the operation plan, and reducing on-site commissioning time.

[0114] The salt pond plastic tarpaulin deployment and recovery system and control method provided by this invention systematically solves a series of key technical problems existing in the prior art, such as imprecise traction control, high running resistance, easy derailment and jamming, low degree of automation, and poor environmental adaptability, through the structural innovation of adaptive float chain, pre-set deflection, streamlined design, modular splicing and the functional innovation of intelligent sensor control system, deep integration of tension closed-loop PID control, position detection and safety interlock.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A salt marsh tarping system comprising: The system comprises: a plastic tarpaulin winding unit arranged at one end of the salt pond, comprising a floating winding shaft for winding the plastic tarpaulin and a first driving mechanism for driving the floating winding shaft to rotate; a traction unit comprising at least two traction winches arranged on the cofferdam of the salt pond, the traction winches being wound with traction ropes; an adaptive float chain, the two ends of which are connected with the free ends of the traction ropes, and the back end of which is fixedly connected with the free end of the plastic tarpaulin; the float chain is composed of a plurality of float monomers which are axially spliced by a splicing mechanism, and the float chain has a preset deflection protruding in the direction of traction of the plastic tarpaulin under the condition of no external force; each of the float monomers is internally provided with an air-tight cavity; a control cabinet, the control cabinet being internally provided with a control system, comprising: a tension sensing module for real-time detection of the tension of the traction rope; a position detection module for detection of the travel end points of the float chain or the plastic tarpaulin; a controller electrically connected with the first driving mechanism, the traction winches, the tension sensing module and the position detection module respectively; wherein the controller is configured to control the traction winches and the first driving mechanism to synchronously operate when the deployment or retraction operation is performed, and dynamically adjust the output rotation speed of the driving mechanism based on the real-time tension value fed back by the tension sensing module, so as to maintain the real-time tension value within a preset constant tension range.

2. The salt pond tarp retrieval system of claim 1, wherein, The target radius of curvature R of the preset deflection is determined by the total length L of the pontoon chain and the target sag h0, and is calculated by the formula R = L ² / (8 x h0), which is derived from the geometric relationship that the pontoon chain is approximately a circular arc: (L / 2) ² ≈2Rh0, where L is the total length of the pontoon chain in millimeters (mm); and h0 is the sag of the pontoon chain under the deflection in millimeters (mm).

3. The salt pond tarp retrieval system of claim 2, wherein, The target sag h0 is in the range of 200mm to 500mm.

4. The salt pond tarp retrieval system of claim 1, wherein, The cross section of the float monomer is streamlined, the width direction of which forms a buoyancy surface mainly used for providing buoyancy, and the two sides of the width direction respectively form a front and a rear drag-reducing water surface used for reducing the drag; the front and rear drag-reducing water surfaces have concentric curvature.

5. The salt pond tarp retrieval system of claim 4, wherein, The float chain is provided with a plastic tarpaulin fixing part, the plastic tarpaulin fixing part comprising a bracket arranged on the rear drag-reducing water surface and a detachable fastener arranged on the bracket for fixedly connecting the plastic tarpaulin.

6. The salt pond tarp retrieval system of claim 1, wherein, The splicing mechanism comprises a transition cylinder, a splicing flange and a sealing end plate embedded in the transition cylinder, the sealing end plate being provided with an air nozzle with a one-way valve; the transition cylinder is provided with a rib plate extending in the axial direction at the connection with the end of the float monomer.

7. The salt pond tarp retrieval system of claim 1, wherein, The outside of the float monomer at the two ends of the float chain is provided with a shore guide wheel, and the rotation axis of the guide wheel is parallel to the cross section of the float monomer.

8. The salt pond tarp retrieval system of claim 1, wherein, The gas in the air-tight cavity is an inert gas with a pressure maintained at 0.1MPa to 0.15MPa.

9. The salt pond tarp retrieval system of claim 1, wherein, The float monomer is welded by steel material with a yield strength not less than 235MPa, and the outer surface of the float monomer is provided with a corrosion-resistant coating.

10. The salt pond tarp retrieval system of claim 1, wherein, The position detection module comprises a first arrival switch arranged at the deployment end point of the plastic tarpaulin and a second arrival switch arranged at the retraction end point of the plastic tarpaulin.

11. The salt pond tarp retrieval system of claim 1, wherein, The system further comprises a rail entry guide unit, the rail entry guide unit comprising rails arranged along the cofferdams on both sides of the salt pond, a lifting ring or a sliding block for restraining the edge of the plastic tarpaulin which can move along the rails, and a rail entry device for assisting the edge of the plastic tarpaulin to enter the rails; the rail entry device is provided with a rail entry device inclination angle adjusting device.

12. The salt pond tarp retrieval system of claim 11, wherein, The orbiting device tilt angle adjusting device comprises a suspension member, an orbiting device tilt lifter and an orbiting guide mechanism; the suspension member is fixedly arranged on a salt pond cofferdam; the orbiting device tilt lifter is installed on the suspension member and comprises a driving box, a linear transmission mechanism arranged in the driving box and an articulated connecting rod driven by the linear transmission mechanism to move linearly; the orbiting guide mechanism comprises an orbiting device upper slide plate, and the end of the articulated connecting rod is connected with the orbiting device upper slide plate; the orbiting device tilt lifter drives the orbiting guide mechanism to swing around the articulated point by driving the articulated connecting rod to move, so as to adjust the tilt angle thereof.

13. The salt pond tarp retrieval system of claim 12, wherein, A front anti-derailing traction ball is connected to the traction rope, and the anti-derailing traction ball is located in the track.

14. The salt pond tarp retrieval system of claim 1, wherein, A non-powered salt remover is arranged on the traction winch; the non-powered salt remover is arranged at a position before the traction rope enters the winding drum, and a channel for the traction rope to pass through is arranged; the non-powered salt remover is installed on a guide shaft, the guide shaft is fixed to the winch frame and located in front of the winding drum, and the non-powered salt remover can freely slide along the axial direction of the guide shaft.

15. The saltwater pond tarp retraction system of claim 14, wherein, The non-powered salt remover comprises at least one salt removing unit, and the salt removing unit has at least one U-shaped scraper with an opening facing upward, two inner side walls of the U-shaped scraper forming two side walls of the channel and being in contact with the surface of the traction rope or having a gap of not more than 3 mm.

16. The salt pond tarp retrieval and deployment system of claim 1, wherein, The automatic plastic tarpaulin drainage device also comprises a plastic tarpaulin automatic drainage device for draining rainwater deposited on the surface of the plastic tarpaulin, the plastic tarpaulin automatic drainage device comprising: a drainage pipeline comprising a siphon water inlet section, a flexible connection section and a drainage section connected in sequence, for guiding rainwater deposited on the plastic tarpaulin to a drainage ditch; A support system for supporting the drainage pipeline; A siphon energy storage pipeline system comprising an energy storage water inlet pipe and a water pump, one end of the energy storage water inlet pipe extending to the vicinity of the water inlet of the siphon water inlet section, and the other end connected to the siphon water inlet section, and the water pump connected in series to the energy storage water inlet pipe; A first control valve arranged at the water inlet of the siphon water inlet section; A second control valve arranged at the water outlet of the drainage section; during drainage, first close the first control valve and the second control valve, and then start the water pump to fill the energy storage water inlet pipe with water to form the power of siphon; The siphon water inlet section is hingedly installed on the support system through a hinge shaft, and the hinge shaft is connected with a driving motor for driving the siphon water inlet section to swing around the hinge shaft; When the driving motor is configured to drive the siphon water inlet section to swing downward, the water inlet thereof presses down the plastic tarpaulin to form a water collection area; when the driving motor is configured to drive the siphon water inlet section to swing upward, the plastic tarpaulin is avoided.

17. The plastic tarpaulin automatic drainage device based on the siphon principle according to claim 16, characterized in that: The support system comprises the first support and the second support, the first support being used for supporting the siphon water inlet section and the driving motor thereof, and the second support being used for fixing the water pump.

18. The automatic drainage device for plastic sheeting based on the siphon principle according to claim 16, characterized in that: The first control valve is a normally closed check valve, which is automatically opened when the pressure in the siphon pipe is lower than atmospheric pressure and is automatically closed when the pressure is higher than atmospheric pressure; the second control valve is a controllable opening check valve, which is automatically opened when the pressure in the siphon pipe reaches a set value and is kept open under the action of water flow and is automatically closed after the water flow disappears.

19. The automatic drainage device for plastic sheeting based on the siphon principle according to claim 16, characterized in that: The water suction port of the siphon water intake section is provided with a blocking cage.

20. The salt pond tarp retrieval and deployment system of claim 1, wherein, The floating winding shaft of the plastic tarpaulin winding unit is installed through a portal frame, and a top roller lifter is arranged on the portal frame to adjust the floating height of the floating winding shaft according to the water level of the salt pond.

21. The salt pond tarp retrieval and deployment system of claim 1, wherein, The controller is further connected with an emergency stop button and is configured to immediately cut off the power supply of all driving mechanisms and the traction winch when the user triggers the emergency stop button or the real-time tension value exceeds a safety threshold.

22. The salt pond tarp deployment system of claim 1, wherein, The controller is a programmable logic controller (PLC), and the dynamic adjustment is realized by changing the motor speed of the first driving mechanism through the PLC control of the frequency converter.

23. A control method for the salt marsh reed take-up and pay-off system according to any one of claims 1-10, 20-22, characterized in that, The method comprises the following steps: an unwinding control step; receiving an unwinding start signal; controlling two traction winches to perform a rope winding operation and controlling the first driving mechanism to drive the floating winding shaft to perform a winding operation; real-time acquisition of the tension value fed back by the tension sensing module; comparison of the tension value with a preset tension range and dynamic adjustment of the output speed of the first driving mechanism through a PID control algorithm to stabilize the tension within the preset range; control of all driving mechanisms and traction winches to stop when the position detection module detects that the floating tube chain reaches the unwinding end point; a winding-up control step; receiving a winding-up start signal; controlling the first driving mechanism to drive the floating winding shaft to perform a winding operation and controlling two traction winches to perform a rope unwinding operation; real-time acquisition of the tension value fed back by the tension sensing module; comparison of the tension value with a preset tension range and dynamic adjustment of the output speed of the first driving mechanism through a PID control algorithm to stabilize the tension within the preset range; control of all driving mechanisms and traction winches to stop when the position detection module detects that the floating tube chain reaches the winding-up end point; The unwinding start signal or the winding-up start signal is triggered by an operator through a local touch screen or a remote controller or is automatically generated by the system after receiving an external weather warning signal.

24. The control method according to claim 23, characterized by, In the unwinding control step, the minimum value of the radial tension F is determined through the following formula: F≥2×M0 / L, wherein M0 is an initial bending moment required to maintain the preset arc shape, and L is the total length of the floating tube chain; The initial bending moment M0 is determined through the following formula: M0=E×I / R, wherein E is the elastic modulus of the floating tube chain material, I is the overall sectional moment of inertia of the floating tube chain, and R is the target curvature radius. The cross section of the single-cell pontoon is simplified to a rectangle, and its moment of inertia I 单 = (b x h ³ ) / 12, where b is the width and h is the height; The total moment of inertia I of the N pontoons 总 =N×I 单 N represents the number of individual pontoons, and N is greater than or equal to 1.

25. The control method according to claim 24, wherein After the radial tension F is applied, the residual sag of the pontoon chain (h ' ) is predicted or verified by the following equation: h ' = h0 x (1 - (F x L / 2) / M0), where h0 is the target sag, M0 is the initial bending moment required to maintain the preset camber; in the control process, the predicted residual sag h' is used as an auxiliary judgment basis: when h'≤1 mm, it is considered that the pontoon chain has reached the expected control target of nearly straightening.

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