Self-adaptive micro-sprinkling irrigation system under photovoltaic panel

Abstract

The invention discloses a self-adaptive micro-spray irrigation system under a photovoltaic panel, which comprises a spray irrigation integrated bracket arranged on a photovoltaic bracket, an environment sensing unit and a control center, and is characterized in that the control center is electrically connected with the spray irrigation integrated bracket and the environment sensing unit; the spray irrigation integrated support comprises a vortex centrifugal spray head used for spray irrigation, an electrostatic loading assembly is arranged at a nozzle outlet of the vortex centrifugal spray head, and direct-current voltage is applied to sprayed fog drops. The spray head is controlled to always keep a safe distance from the lower edge of the photovoltaic panel, zero interference between the device and a photovoltaic structure is realized, and meanwhile, the vortex centrifugal spray head is combined with an electrostatic adsorption technology, so that fog drops directionally settle to soil, and the path that the water drops rebound to the surface of the photovoltaic panel is blocked from a physical mechanism; and the problem that the light transmittance of the photovoltaic panel is reduced due to calcium and magnesium ion deposition is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural-photovoltaic complementarity, and in particular to an adaptive micro-sprinkler irrigation system under a photovoltaic panel. Background Art

[0002] Currently, agricultural irrigation under photovoltaic panels mainly relies on two types of technologies: fixed drip irrigation systems and mobile sprinkler irrigation devices. The fixed drip irrigation system fixes the drip tape between the planting rows. Although it can save water, it has the following defects: poor spatial adaptability: the photovoltaic support columns hinder the layout of the drip tape, resulting in uneven irrigation in the edge area under the panel; humidity control lag: relying on the timing controller, it cannot respond to the micro-environment humidity fluctuations caused by sudden changes in light intensity. The mobile sprinkler irrigation device moves along the track between the photovoltaic arrays to spray, but there are still key problems: structural conflict: the sprinkler vehicle's mechanical arm interferes with the photovoltaic panel cleaning mechanism when it is deployed; water stain pollution: large water droplets cause calcium scale to deposit on the panel surface, reducing the light transmittance of the photovoltaic module. In response to the above problems, this application proposes a solution. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide an adaptive micro-sprinkler irrigation system under photovoltaic panels, which can solve the three major problems existing in the prior art, namely, water pollution risk, mechanical structure conflict and irrigation blind spots, improve land utilization, save water and increase efficiency.

[0004] Technical solution: The adaptive micro-sprinkler irrigation system under a photovoltaic panel described in the present invention comprises an integrated sprinkler irrigation bracket, an environmental sensing unit and a control center arranged on the photovoltaic bracket. The control center is electrically connected to the integrated sprinkler irrigation bracket and the environmental sensing unit. The integrated sprinkler irrigation bracket comprises a vortex centrifugal nozzle for spray irrigation. An electrostatic loading component is arranged at the nozzle outlet of the vortex centrifugal nozzle to apply a DC voltage to the sprayed droplets.

[0005] Preferably, the integrated sprinkler bracket includes a longitudinal beam slide rail, a telescopic spray rod and an embedded pipe, the longitudinal beam slide rail includes a T-slot arranged on the longitudinal beam of the photovoltaic bracket and a linear guide rail arranged in the T-slot, the telescopic spray rod is connected to the guide rail through a slider, and a plurality of vortex centrifugal nozzles are installed at the end of the telescopic spray rod. The embedded pipe is pre-buried inside the column of the photovoltaic bracket, connected to the pipeline of the telescopic spray rod through a quick connector, and provides water flow to the vortex centrifugal nozzle.

[0006] Preferably, the environmental sensing unit includes a multispectral sensor and a soil moisture probe. The multispectral sensor is installed on the back of the photovoltaic panel to monitor light intensity, air humidity and leaf temperature. The soil moisture probes are buried in the soil at different positions away from the soil surface to measure the volume moisture content of the corresponding soil depth.

[0007] Preferably, the control center includes a main control PLC controller and an actuator. The main control PLC controller receives the data information detected by the environmental perception unit and controls the actuator to work. The actuator includes a servo motor, a pulse solenoid valve, and an electrostatic generator. The servo motor provides power to the integrated sprinkler bracket. The pulse solenoid valve controls the water spray pressure of the vortex centrifugal nozzle. The electrostatic generator provides direct current to the electrostatic loading component.

[0008] Preferably, the vortex centrifugal nozzle includes a spherical cavity head, a joint, and a nozzle. The joint communicates with the top of the spherical cavity head to introduce water flow. The nozzle is arranged at the bottom of the spherical cavity head to spray water flow. Inside the cavity head, a diversion layer, a fragmentation layer, and a flow stabilization layer are respectively arranged from top to bottom. Multiple groups of spiral diversion vanes are arranged in the diversion layer to accelerate the water flow; a honeycomb microporous array is arranged in the fragmentation layer to break the air bubbles; a curved surface rectifying grid is arranged in the flow stabilization layer to eliminate vortex oscillation.

[0009] Preferably, the spiral diversion vanes are designed with a tapered spiral flow channel, and the blade inclination angle linearly decreases from the inlet end to the outlet end. At the same time, a filter screen for intercepting impurities is arranged at the inlet.

[0010] Preferably, the honeycomb microporous array adopts a hexagonal honeycomb structure, and the pore diameter is distributed in a gradient along the radial direction, decreasing layer by layer from the inner circle to the middle circle and the outer circle. The difference between adjacent pore diameters is not less than 100 μm. At the same time, a titanium nitride coating is sprayed on the inner wall of the micropores of the honeycomb microporous array.

[0011] Preferably, the curved surface rectifying grid adopts an asymmetric Bessel curve grid, is made of nickel-based superalloy, and is formed by a laser powder bed fusion process. After the curved surface rectifying grid is formed, it is subjected to electrolytic polishing and stress annealing under argon protection.

[0012] Preferably, the electrostatic loading component includes an annular electrode embedded at the nozzle outlet of the vortex centrifugal nozzle and a quartz glass isolation ring for blocking the backflow of droplets. The annular electrode adopts a double-nested electrode structure. The inner ring is the cathode, loaded with a negative voltage, and the outer ring is the anode, grounded. There is a spacing between the cathode and the anode. The electric field of the annular electrode is simulated by COMSOL Multiphysics to optimize the electrode curvature. At the same time, the substrate of the annular electrode is encapsulated with alumina ceramic.

[0013] Preferably, the annular electrode adjusts the voltage in real time according to the droplet diameter to maintain the charge-to-mass ratio at -3.2×10 -5 ~-3.8×10 -5 C / kg.

[0014] Advantageous effects: Compared with the prior art, the present invention has the following remarkable advantages:

[0015] (1) By integrating the integrated sprinkler bracket directly on the photovoltaic bracket and using a servo motor to control the extension and retraction of the spray rod, the sprinkler head always maintains a safe distance from the bottom edge of the photovoltaic panel during the sprinkler operation, ensuring that there is no physical conflict with photovoltaic operation and maintenance robots, cleaning equipment, etc., and achieving zero interference between the device and the photovoltaic structure;

[0016] (2) Integrate with photovoltaic structure to reduce the land occupation of independent irrigation facilities and improve land utilization;

[0017] (3) By combining the vortex centrifugal nozzle with the electrostatic adsorption technology, the droplets are directed to settle on the soil, physically blocking the path of the droplets rebounding to the surface of the photovoltaic panel, thus avoiding the problem of decreased light transmittance of the photovoltaic panel caused by calcium and magnesium ion deposition;

[0018] (4) Monitor multi-source data such as light intensity and leaf temperature through the environmental sensing unit, generate nonlinear pulse irrigation strategies based on the multi-source data, improve irrigation efficiency, and simultaneously reduce the temperature of photovoltaic panels and improve crop water use efficiency, thereby achieving energy-water synergy in the agricultural photovoltaic system;

[0019] (5) Based on embedded pipes and telescopic spray rods, the sprinkler irrigation coverage rate reaches ≥95%, while the existing technology is 67-92%, especially for the 30cm high shielding area around the photovoltaic support column to achieve no dead angle irrigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention combined with a photovoltaic support.

[0021] Figure 2 It is a schematic enlarged view of a part of the three-dimensional structure of the present invention.

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of the vortex centrifugal nozzle in the present invention.

[0023] Figure 4 It is a three-dimensional structural cross-sectional view of the vortex centrifugal nozzle in the present invention.

[0024] Figure 5 It is a side cross-sectional view of the vortex centrifugal nozzle in the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0026] Embodiment 1:

[0027] See attached Figures 1 to 5Figure, the present invention includes an integrated sprinkler support, an environmental perception unit, and a control center disposed on the photovoltaic support 1. Among them, the control center is electrically connected to the integrated sprinkler support and the environmental perception unit. The integrated sprinkler support includes a vortex centrifugal nozzle 2 for spray irrigation. An electrostatic loading component is provided at the outlet of the nozzle 7 of the vortex centrifugal nozzle 2 to apply a DC voltage to the sprayed droplets.

[0028] In this embodiment, the integrated sprinkler support includes a longitudinal beam slide rail 3, a telescopic spray rod 4, and an embedded pipeline. The longitudinal beam slide rail 3 includes a T-shaped groove provided on the longitudinal beam of the photovoltaic support and a linear guide rail provided in the T-shaped groove. The telescopic spray rod 4 is connected to the linear guide rail through a slider. Multiple groups of vortex centrifugal nozzles 2 are installed at the end of the telescopic spray rod 4. The embedded pipeline is buried inside the column of the photovoltaic support 1 and is connected to the pipeline of the telescopic spray rod through a quick connector to provide water flow to the vortex centrifugal nozzle 2.

[0029] In this embodiment, the environmental perception unit includes a multispectral sensor and a soil moisture probe. The multispectral sensor is installed on the back of the photovoltaic panel 14 to monitor the light intensity, air humidity, and leaf surface temperature. The soil moisture probes are respectively buried in the soil at positions 10 cm, 20 cm, and 30 cm from the soil surface to measure the volumetric water content of the corresponding soil depths.

[0030] In this embodiment, the control center includes a main control PLC controller and an actuator. The main control PLC controller receives the data information detected by the environmental perception unit and controls the operation of the actuator. The actuator includes a servo motor, a pulse solenoid valve, and an electrostatic generator. The servo motor provides power to the integrated sprinkler support. The pulse solenoid valve controls the water pressure sprayed by the vortex centrifugal nozzle 2. The electrostatic generator provides DC to the electrostatic loading component.

[0031] In this embodiment, the vortex centrifugal nozzle 2 includes a spherical cavity head 5, a joint 6, and a nozzle 7. Among them, the joint 6 communicates with the top of the spherical cavity head 5 to introduce water flow. The nozzle 7 is provided at the bottom of the spherical cavity head 5 to spray water flow. Inside the spherical cavity head 5, a diversion layer 8, a fragmentation layer 9, and a steady flow layer 10 are respectively provided from top to bottom. Six groups of spiral diversion blades 11 are provided in the diversion layer 8 to accelerate the water flow; a honeycomb micropore array 12 is provided in the fragmentation layer 9 to break the bubbles; a curved surface rectifying grid 13 is provided in the steady flow layer 10 to eliminate vortex oscillation.

[0032] In this embodiment, the spiral diversion blades 11 are designed with a tapered spiral flow channel. The blade inclination angle linearly decreases from 45° at the inlet end to 15° at the outlet end, so that the cross-sectional area reduction rate of the flow channel is 62%. When the water flow passes through the spiral diversion blades 11, the Coriolis effect is generated, and the flow velocity is increased from 1.2 m / s to 12.5 m / s. At the same time, a primary filter with a pore diameter of 1 mm is provided at the inlet to intercept impurities ≥500 μm.

[0033] In this embodiment, the honeycomb micropore array 12 adopts a hexagonal honeycomb structure, and the pore diameter is distributed in a gradient along the radial direction, ranging from 500 μm in the inner circle to 300 μm in the middle circle, and then to 200 μm in the outer circle. The porosity decreases from 68% to 42%. Through the pore diameter mutation design with the adjacent pore diameter difference ≥ 100 μm, a local low-pressure area is formed in the flow channel to induce the collapse of cavitation bubbles. At the same time, a titanium nitride coating is sprayed on the inner wall of the micropores of the honeycomb micropore array 12 to inhibit the attachment of calcium and magnesium salt crystals.

[0034] In this embodiment, the curved surface rectifying grid 13 adopts an asymmetric Bessel curve grid, with a curvature radius R = 1.5 mm and a grid stagger angle of 15°. The grid density is optimized by computational fluid dynamics (CFD), reducing the turbulence intensity from 12% to 3.8% and destroying the periodicity of eddy currents.

[0035] The curved surface rectifying grid 13 is made of a nickel-based superalloy and is formed by the laser powder bed fusion process, with a pressure tolerance ≥ 5 MPa. The printing accuracy of the micropores in the curved surface rectifying grid 13 is ±10 μm, and the surface roughness Ra ≤ 1.6 μm. After forming, the curved surface rectifying grid 13 is subjected to electrolytic polishing to eliminate the residual internal support, and stress annealing is carried out at 500 °C for 2 hours under argon protection.

[0036] In this embodiment, the electrostatic loading component includes an annular electrode embedded at the outlet of the nozzle 7 of the vortex centrifugal spray head 2 and a quartz glass isolation ring for blocking the backflow of droplets. The annular electrode adopts a double-nested electrode structure, with the inner ring as the cathode, loaded with -12 V voltage, the outer ring as the anode, grounded, and the distance between the cathode and the anode is 2 mm. The electric field of the annular electrode is simulated by COMSOL Multiphysics, and the electrode curvature is optimized to ensure that the electric field strength gradient ≤ 5%. At the same time, the substrate of the annular electrode is encapsulated with alumina ceramics, with a withstand voltage level > 20 kV and an IP68 protection level.

[0037] In this embodiment, the annular electrode adjusts the voltage in real time according to the droplet diameter to maintain the charge-to-mass ratio at -3.2×10 -5 ~-3.8×10 -5 C / kg.

[0038] Embodiment 2:

[0039] When the present invention is in operation, taking the cultivation of wolfberries as an example:

[0040] Initialization stage: The telescopic spray rod 4 retracts to the root of the longitudinal beam of the photovoltaic support 1, and the integrated sprinkler irrigation support is in the standby state. The multispectral sensor uploads environmental data every 5 minutes, and the soil probe updates the soil moisture every hour.

[0041] Irrigation decision-making stage: Data fusion: When the leaf surface temperature > 32°C and the air humidity < 45%, an irrigation demand is triggered; Parameter calculation: The control center combines the water demand law during the swelling period of wolfberries to generate a pulse irrigation instruction: valve opening for 3 s / valve closing for 120 s, cycling 5 times; Positioning adjustment: The servo motor drives the telescopic spray rod 4 to extend to a position of 1.8 m, and the distance between the vortex centrifugal nozzles 2 is automatically adjusted to 50 cm to match the planting row spacing of wolfberries.

[0042] Irrigation execution stage: Atomized spraying: The pulse solenoid valve opens, and water flow with a pressure of 0.25 MPa enters the vortex centrifugal nozzle 2 to generate mist droplets with a particle size ≤ 200 μm; Electrostatic adsorption: The nozzle 7 is loaded with a voltage of -12 V. After the mist droplets are negatively charged, they are attracted by the soil electric field, and the sedimentation speed is increased to 1.2 m / s, while that of conventional mist droplets is only 0.3 m / s. The charged mist droplets reach the root zone along a parabolic trajectory under the action of the electric field, avoiding the photovoltaic panel 14.

[0043] Collision protection: During the process of the telescopic spray rod 4 moving following the slider, the distance from the photovoltaic panel 14 is detected in real time. If it is < 50 cm, it will immediately stop and retreat.

Claims

1. An adaptive micro-sprinkler irrigation system under a photovoltaic panel, characterized in that: The invention comprises an integrated sprinkler and irrigation bracket, an environment sensing unit and a control center arranged on a photovoltaic bracket (1); the control center is electrically connected to the integrated sprinkler and irrigation bracket and the environment sensing unit; the integrated sprinkler and irrigation bracket comprises a vortex centrifugal nozzle (2) for spray irrigation; an electrostatic loading component is arranged at the nozzle outlet of the vortex centrifugal nozzle to apply a DC voltage to the sprayed droplets.

2. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 1, characterized in that: The integrated sprinkler irrigation support comprises a longitudinal beam slide rail (3), a telescopic spray rod (4) and an embedded pipe, wherein the longitudinal beam slide rail (3) comprises a T-shaped groove arranged on the longitudinal beam of the photovoltaic support (1) and a linear guide rail arranged in the T-shaped groove, the telescopic spray rod (4) is connected to the guide rail via a slider, and a plurality of vortex centrifugal nozzles (2) are installed at the end of the telescopic spray rod (4), and the embedded pipe is pre-buried in the column of the photovoltaic support (1), connected to the pipeline of the telescopic spray rod via a quick connector, and provides water flow to the vortex centrifugal nozzle (2).

3. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 1, characterized in that: The environmental sensing unit comprises a multispectral sensor and a soil moisture probe. The multispectral sensor is installed on the back of the photovoltaic panel (14) to monitor light intensity, air temperature and leaf surface temperature. The soil moisture probes are buried in the soil at different positions away from the soil surface to measure the volumetric moisture content at corresponding soil depths.

4. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 1, characterized in that: The control center includes a main PLC controller and an actuator. The main PLC controller receives data information detected by the environmental sensing unit and controls the operation of the actuator. The actuator includes a servo motor, a pulse solenoid valve and an electrostatic generator. The servo motor provides power to the integrated sprinkler bracket, the pulse solenoid valve controls the water pressure of the vortex centrifugal nozzle, and the electrostatic generator provides direct current to the electrostatic loading component.

5. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 1, characterized in that: The vortex centrifugal nozzle (2) comprises a spherical cavity head (5), a joint (6) and a nozzle (7); the joint (6) is connected to the top of the spherical cavity head (5) to introduce water flow; the nozzle (7) is arranged at the bottom of the spherical cavity head (5) to spray water flow; the spherical cavity head (5) is provided with a guide layer (8), a crushing layer (9) and a stabilizing layer (10) from top to bottom; the guide layer (8) is provided with a plurality of groups of spiral guide blades (11) to accelerate the water flow; the crushing layer (9) is provided with a honeycomb micropore array (12) to crush cavitation bubbles; the stabilizing layer (10) is provided with a curved surface rectifying grid (13) to eliminate vortex oscillation.

6. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 5, characterized in that: The spiral guide blade (11) is designed with a gradually contracting spiral flow channel, and the blade inclination angle decreases linearly from the inlet end to the outlet end. At the same time, a filter screen for intercepting impurities is arranged at the inlet.

7. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 5, characterized in that: The honeycomb micropore array (12) adopts a hexagonal honeycomb structure, and the apertures are distributed in a gradient manner in the radial direction, decreasing layer by layer from the inner circle to the middle circle and the outer circle, and the difference between adjacent apertures is not less than 100 μm. At the same time, a titanium nitride coating is sprayed on the inner wall of the micropores of the honeycomb micropore array (12).

8. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 5, characterized in that: The curved rectifying grid (13) adopts an asymmetric Bezier curve grid and a nickel-based high-temperature alloy and is formed by a laser powder bed melting process. After forming, the curved rectifying grid (13) is electrolytically polished and stress annealed under argon protection.

9. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 5, characterized in that: The electrostatic loading component comprises an annular electrode embedded at the outlet of a nozzle (7) of a vortex centrifugal nozzle (2) and a quartz glass isolation ring for blocking the backflow of mist droplets. The annular electrode adopts a double nested electrode structure, wherein the inner ring is a cathode loaded with a negative voltage, and the outer ring is an anode grounded. There is a distance between the cathode and the anode. The electric field of the annular electrode is simulated by COMSOL Multiphysics to optimize the electrode curvature. Meanwhile, the substrate of the annular electrode is packaged with alumina ceramics.

10. The self-adaptive micro-sprinkler irrigation system under a photovoltaic panel according to claim 9, characterized in that: The annular electrode adjusts the voltage in real time according to the droplet size to maintain the charge-to-mass ratio at -3.2×10 -5 ~-3.8×10 -5 C / kg.

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