A ventilation device for an agricultural greenhouse

Abstract

The application relates to the technical field of agricultural greenhouses, in particular to a ventilation device for an agricultural greenhouse, which comprises a wind guide pipe, a rectifier pipe, a first electromagnet and a second electromagnet, a plurality of one-way valves are uniformly arranged on the lower part of the side wall of the wind guide pipe in a circumferential direction, when the one-way valves are opened, the gas in the rectifier pipe enters the wind guide pipe through the one-way valves; the openings at the two ends of the rectifier pipe are provided with radially inwardly extending reduced-diameter parts, the inner side of the reduced-diameter parts is in sealing cooperation with the outer side of the wind guide pipe; the first electromagnet is fixedly connected to the upper part of the inner side of the rectifier pipe, the second electromagnet is located below the first electromagnet; the outer side of the second electromagnet is in sliding cooperation with the inner side of the rectifier pipe, the inner side of the second electromagnet is in sliding gap cooperation with the outer side of the wind guide pipe; the second electromagnet and the rectifier pipe are connected with a reset spring. The device can realize air convection in the greenhouse, reduce the air flow speed, reduce energy consumption and avoid crop damage.

Description

Technical Field

[0001] This invention relates to the field of agricultural greenhouse technology, and more specifically to a ventilation device for agricultural greenhouses. Background Technology

[0002] Inside agricultural greenhouses, hot air (low density and light weight) naturally rises along the curvature of the greenhouse film, eventually accumulating at the highest point. If this heat accumulates at the top and cannot escape, the temperature at the top is often several degrees higher than in the middle. The tops of crops (growing points and tender leaves) closest to the film are most susceptible to heat scorching, a phenomenon known as "leaf burn," which negatively impacts crop growth and causes economic losses. At midday, the vents at the top of the greenhouse need to be opened to allow heat to escape. However, after closing the greenhouse in the evening, on cloudy days, or at night, the soil and walls, having absorbed heat during the day, slowly release it. But as the heat rises and accumulates at the top, the crop layer cools first, causing a rapid drop in ground temperature. Therefore, forced convection is needed to maintain the greenhouse's insulation. However, conventional convection methods dissipate energy quickly, requiring higher wind speeds to reduce the temperature difference inside the greenhouse, increasing energy consumption. Furthermore, high-speed airflow is detrimental to crop growth and may cause dust problems. Therefore, while creating convection, the internal airflow speed should be minimized.

[0003] Vortex airflow can stably transport hot air downwards in the greenhouse without causing dust or bending the tender shoots with high-speed airflow. However, because the air supply channel needs to be stationary during the generation of the vortex, the current vortex airflow rate is insufficient for direct application in the field of greenhouse ventilation. Summary of the Invention

[0004] The purpose of this invention is to provide a ventilation device for agricultural greenhouses that reduces airflow speed while achieving air convection inside the greenhouse, thereby reducing energy consumption and preventing crop damage.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A ventilation device for agricultural greenhouses includes an air guide duct, a rectifier tube sleeved outside the air guide duct, and a first electromagnet and a second electromagnet connected to the inner wall of the rectifier tube. Multiple one-way valves communicating with the inner and outer sides of the air guide duct are evenly arranged circumferentially on the lower part of the side wall of the air guide duct. When the one-way valves are open, gas in the rectifier tube enters the air guide duct through the one-way valves. The rectifier tube has radially inwardly extending constricted sections at both ends, with the inner side of the constricted section sealingly fitted to the outer side of the air guide duct. The first electromagnet is fixedly connected to the upper inner side of the rectifier tube, and the second electromagnet is located below the first electromagnet. The outer side of the second electromagnet is slidably connected to the inner side of the rectifier tube, and the inner side of the second electromagnet is in sliding clearance fit with the outer side of the air guide duct. A return spring is connected between the second electromagnet and the rectifier tube.

[0007] Furthermore, the first electromagnet is fixed to the lower side of the reduced diameter section of the upper opening of the rectifier tube, and the reset spring is connected between the second electromagnet and the reduced diameter section of the lower opening of the rectifier tube.

[0008] Furthermore, one of the outer side of the second electromagnet and the inner side of the rectifier tube is provided with at least one groove extending along the axial direction of the rectifier tube, and the other is provided with a slider adapted to the groove.

[0009] Furthermore, the inner side of the rectifier tube is provided with at least one groove extending along the axial direction of the rectifier tube, and the outer side of the second electromagnet is provided with a slider adapted to the groove; the return spring is limited and arranged in the groove, the upper end of the return spring is fixedly connected to the lower side of the slider of the second electromagnet, and the lower end of the return spring is fixedly connected to the lower groove wall of the groove.

[0010] Furthermore, it also includes an elastic rope, one end of which is fixedly connected to the second electromagnet, and the other end of which is fixedly connected to the valve disc of the one-way valve; when the second electromagnet moves upward to a preset position, the elastic rope is tightened, assisting the valve disc of the one-way valve to close.

[0011] Furthermore, it also includes a third electromagnet, which is fixed to the lower part of the inner side of the rectifier tube and is located below the second electromagnet; the first electromagnet, the second electromagnet, and the third electromagnet are configured such that: when the air inlet of the air duct is open, the first electromagnet and the second electromagnet generate an attractive force, and the second electromagnet and the third electromagnet generate a repulsive force, which together drive the second electromagnet to move upward along the inner side of the rectifier tube; when the air inlet of the air duct is closed, the first electromagnet and the second electromagnet generate a repulsive force, which drives the second electromagnet to move downward along the inner side of the rectifier tube.

[0012] Furthermore, the reduced diameter portion at the upper opening of the rectifier tube is provided with several pressure relief holes that connect the inside and outside of the rectifier tube.

[0013] Furthermore, it also includes a cylindrical shell and a fixing plate fixed inside the cylindrical shell, the plane of which the fixing plate is located is perpendicular to the axis of the cylindrical shell; a plurality of air guide pipes are fixed to one side of the fixing plate, and a valve and a driving element for driving the valve to open and close are connected to the air inlet of the air guide pipe.

[0014] Furthermore, it also includes a mounting plate fixed inside the cylindrical housing, on which a plurality of air intake fans corresponding to the positions of the air duct are fixed.

[0015] Furthermore, a tapered pipe is connected to the lower end of the air duct, and the large-diameter end of the tapered pipe is connected to the air outlet at the lower end of the air duct.

[0016] The present invention has the following unexpected beneficial effects:

[0017] 1. Micro-gas counter-current control: When the duct valve is closed, the residual airflow in the duct only tends to move downwards, not in large quantities. Therefore, if the counter-current flow rate is too large, it will not only fail to reduce the settling time of the airflow in the duct, but will also cause the airflow in the duct to change from moving downwards to moving upwards under the action of the counter-current flow, and finally moving downwards again, thus prolonging the settling time. The device described in this invention uses a periodic linkage control of opening and closing the air duct. During the closing phase, the opposing magnetic fields of the first and second electromagnets, combined with the negative pressure inside the rectifier tube and the gravity of the second electromagnet, drive the second electromagnet to move rapidly downwards. This forces air from the rectifier tube through the one-way valve into the air duct. Since the rectifier tube is located only outside the air duct and has a small cavity size, it precisely counteracts residual turbulent airflow without changing the direction of airflow within the air duct. Simultaneously, the open valve increases airflow resistance, significantly shortening the airflow calming time within the air duct under this dual effect, reducing the time required for the air duct to stabilize upon closure. This increases the airflow volume per unit time, allowing the hot airflow at the top of the greenhouse to be stably transmitted downwards under the action of the vortex ring, reducing the temperature difference between the top and bottom of the greenhouse and achieving low-energy insulation.

[0018] 2. Instantaneous Airflow Counter-current Response: The device described in this invention employs a collaborative control structure and negative pressure design using multiple electromagnets (first, second, and third electromagnets) and a return spring. This allows for the fastest possible acceleration to drive the second electromagnet, and precise adjustment of its movement trajectory and speed, ensuring a stable and controllable rectification process. Furthermore, the one-way valves are evenly distributed along the outer side of the air duct, ensuring that the backflow airflow and resistance act uniformly across the entire air duct area, guaranteeing uniform airflow output. Stable and uniform airflow provides the foundation for high-quality airflow, effectively reducing diffusion speed during transport, extending the air delivery distance, improving overall air delivery stability, and meeting the ventilation needs of agricultural greenhouses. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0020] Figure 1 This is an exploded view of the ventilation device for agricultural greenhouses described in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the ventilation device for agricultural greenhouses according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the air duct structure according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the rectifier tube described in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the internal structure of the rectifier tube according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the one-way valve described in an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the valve and drive element described in an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram showing the connection between the air duct and the fixing plate according to an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of the working state of the ventilation device for agricultural greenhouses described in an embodiment of the present invention when the air duct is open;

[0029] Figure 10 This is a schematic diagram of the working state of the ventilation device for agricultural greenhouses described in an embodiment of the present invention when the air duct is closed.

[0030] In the diagram, 1—air duct, 2—rectifier tube, 21—reduced diameter section, 22—slide groove, 23—pressure relief hole, 3—first electromagnet, 4—second electromagnet, 41—slider, 5—third electromagnet, 6—one-way valve, 61—valve disc, 7—reset spring, 8—cylindrical housing, 9—fixed plate, 10—valve, 11—drive element, 12—mounting plate, 13—inlet fan, 14—conical tube, 15—mounting hole, 16—contact block, 17—elastic rope. Detailed Implementation

[0031] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can understand other advantages and effects of the present invention based on the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0032] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings are only schematic and are not drawn to scale. In actual implementation, they can be appropriately adjusted according to actual needs, and their component layout may be more complex.

[0033] In one embodiment, see Figures 1 to 8 As shown, the present invention provides a ventilation device for agricultural greenhouses, including an air guide pipe 1, a rectifier pipe 2 sleeved outside the air guide pipe 1, and a first electromagnet 3 and a second electromagnet 4 connected to the inner side wall of the rectifier pipe 2. A plurality of one-way valves 6 are evenly arranged circumferentially on the lower part of the side wall of the air guide pipe 1, connecting the inner and outer sides of the air guide pipe 1. When the one-way valves 6 are opened, the gas in the rectifier pipe 2 enters the air guide pipe 1 through the one-way valves 6.

[0034] The rectifier tube 2 has radially inwardly extending reduced diameter sections 21 at both ends, and the inner side of the reduced diameter section 21 is sealed to the outer side of the air guide tube 1. The first electromagnet 3 is fixedly connected to the upper inner side of the rectifier tube 2, and the second electromagnet 4 is located below the first electromagnet 3; the outer side of the second electromagnet 4 is slidably connected to the inner side of the rectifier tube 2, and the inner side of the second electromagnet 4 is slidably and loosely connected to the outer side of the air guide tube 1; a return spring 7 is connected between the second electromagnet 4 and the rectifier tube 2.

[0035] When the second electromagnet 4 moves upward, the return spring 7 first naturally releases its compressed energy. As the upward distance increases, the return spring 7 gradually stretches and enters a stretched energy storage state. When the second electromagnet 4 moves downward, the return spring 7 first naturally releases its stretched energy. As the downward distance increases, the return spring 7 is gradually compressed and enters a compressed energy storage state. This working mode ensures that the return spring 7 can effectively absorb and release energy during the movement of the second electromagnet 4, providing buffering and auxiliary power for the stable operation of the system.

[0036] For specific work, see Figure 5As shown, when the air inlet of the air duct 1 is open, the first electromagnet 3 and the second electromagnet 4 are energized, and a magnetic force is generated between the first electromagnet 3 and the second electromagnet 4. The return spring 7 is in a natural release compression and energy storage state. As the second electromagnet 4 moves upward, the return spring 7 gradually stretches and enters a stretching and energy storage state, jointly driving the second electromagnet 4 to move upward along the inner side of the rectifier tube 2, so that a negative pressure is generated in the lower part of the inner side of the rectifier tube 2. At this time, under the action of the air pressure at the air inlet of the air duct 1, the one-way valve 6 is in a closed state, ensuring that the airflow passes smoothly through the air duct 1.

[0037] When the air inlet of the air duct 1 is closed, the first electromagnet 3 and the second electromagnet 4 are energized, and a repulsive force is generated between the first electromagnet 3 and the second electromagnet 4. Combined with the gravity of the second electromagnet 4 and the initial negative pressure attraction, the three forces work together to drive the second electromagnet 4 to move rapidly downward along the inner side of the rectifier tube 2, causing the air pressure in the lower part of the inner side of the rectifier tube 2 to rise, opening the one-way valve 6, and squeezing the gas in the lower part of the inner side of the rectifier tube 2 into the air duct 1 through the one-way valve 6. This creates a backflow effect on the turbulent airflow remaining in the air duct 1, accelerating the calming of the airflow.

[0038] The device described in this invention uses a periodic linkage control of opening and closing the air duct 1. During the closing phase of the air duct 1, since the gas inside the air duct 1 is not static when the valve 10 is first closed, it tends to move downwards. Utilizing the opposing magnetic fields of the first electromagnet 3 and the second electromagnet 4, combined with the negative pressure inside the rectifier tube 2 and the gravity of the second electromagnet 4 itself, along with the initial negative pressure attraction, the three forces work together to drive the second electromagnet 4 to move rapidly downwards, squeezing the air inside the rectifier tube 2 from the one-way valve 6 into the air duct 1, thus creating a precise backflow against the residual turbulent airflow. Simultaneously, the valve disc 61 of the one-way valve 6 protrudes from the inner side of the air duct 1, further increasing the airflow resistance of the downward-moving airflow inside the air duct 1. Under this dual effect, the airflow calming time inside the air duct 1 is significantly shortened, reducing the time required for the air duct 1 to stabilize after closure.

[0039] The device described in this invention employs a collaborative control structure of two electromagnets, namely a first electromagnet 3 and a second electromagnet 4, and a return spring 7. This allows for precise adjustment of the movement trajectory and speed of the second electromagnet 4, ensuring a stable and controllable rectification process. Furthermore, the one-way valves 6 are evenly distributed along the outer side of the air duct 1, enabling the backflow airflow and resistance to act uniformly across the entire area of ​​the air duct 1, guaranteeing the uniformity of airflow output. Stable and uniform airflow provides the foundation for high-quality airflow, effectively reducing the diffusion speed during delivery, extending the air delivery distance, improving overall air delivery stability, and meeting the needs for precise, long-distance air delivery in various scenarios.

[0040] See Figure 3 As shown, the side wall of the air duct 1 is provided with an installation hole 15 that is compatible with the one-way valve 6.

[0041] As a preferred embodiment of the present invention, see Figure 5 As shown, the first electromagnet 3 is fixed on the lower side of the reduced diameter section 21 at the upper end opening of the rectifier tube 2, and the reset spring 7 is connected between the second electromagnet 4 and the reduced diameter section 21 at the lower end opening of the rectifier tube 2.

[0042] The first electromagnet 3 and the second electromagnet 4, fixed to the upper reduced-diameter section 21, are vertically aligned and directly opposite each other. The magnetic force between them can be directly transmitted along the central axis of the rectifier tube 2, avoiding lateral force due to installation misalignment and reducing energy loss. Simultaneously, the return spring 7 connects the second electromagnet 4 to the lower reduced-diameter section 21, and its elastic force also acts on the second electromagnet 4 along the central axis, forming an axial three-force synergistic system of upper electromagnetic force, lower elastic force, and the gravity of the second electromagnet. This arrangement makes the force direction of the second electromagnet 4 more concentrated and its movement trajectory more precise, effectively avoiding jamming and tilting caused by uneven force, ensuring its rapid and smooth vertical movement, and improving the triggering timeliness and intensity stability of the backflow.

[0043] In this preferred embodiment, the lower end tapered portion 21 serves as the fixed end of the return spring 7, and its position is fixed at a distance from the upper end first electromagnet 3. This allows the natural length and stretch / compression stroke of the return spring 7 to be precisely matched with the maximum movement range of the second electromagnet 4. For example, when the air duct 1 is opened, the first electromagnet 3 generates an attractive force, pulling the second electromagnet 4 upward. At this time, the return spring 7 first naturally releases its compressed energy storage and then enters a stretched energy storage state. Its elastic force of naturally releasing compressed energy storage can help offset part of the weight of the second electromagnet 4, making the upward movement process lighter. When the air duct 1 is closed, the first electromagnet 3 generates a repulsive force. Combined with the weight of the second electromagnet 4, the stretching elastic force of the return spring 7, and the initial negative pressure attraction, the three forces work together to quickly push the second electromagnet 4 downward, shortening the movement time and further improving the response speed of the airflow backlash.

[0044] As a preferred embodiment of the present invention, see Figure 4 and Figure 5 As shown, one of the outer side of the second electromagnet 4 and the inner side of the rectifier tube 2 is provided with at least one groove 22 extending along the axial direction of the rectifier tube 2, and the other is provided with a slider 41 adapted to the groove 22.

[0045] In this preferred embodiment, the chute 22 extends axially along the rectifier tube 2, and the slider 41 corresponds to and cooperates with the chute 22, which can strictly limit the radial displacement of the second electromagnet 4, that is, the direction perpendicular to the central axis of the rectifier tube 2, ensuring that it only slides up and down axially. Compared with the tilting offset and jamming that may occur without a guide structure, the matching structure of the chute 22 and the slider 41 can keep the second electromagnet 4, the air duct 1, and the rectifier tube 2 coaxial at all times, avoid uneven local gaps caused by radial shaking, avoid airflow leakage from the gaps or the impact of sudden increase in frictional resistance on the movement speed, and ensure uniform air pressure change and stable airflow compression force during the recoil phase.

[0046] As a preferred embodiment of the present invention, see Figure 4 and Figure 5 As shown, the inner side of the rectifier tube 2 is provided with at least one groove 22 extending axially along the rectifier tube 2, and the outer side of the second electromagnet 4 is provided with a slider 41 adapted to the groove 22. The return spring 7 is positioned within the groove 22, with its upper end fixedly connected to the lower side of the slider 41 of the second electromagnet 4, and its lower end fixedly connected to the lower wall of the groove 22.

[0047] This preferred embodiment directly utilizes the groove 22 inside the rectifier tube 2 to support the return spring 7, eliminating the need for an additional independent mounting slot or fixing bracket for the return spring 7. This achieves space reuse between the guide structure and the elastic component, resulting in a more compact internal layout of the rectifier tube 2. It also prevents the return spring 7 from being exposed and occupying airflow channel space, while reducing direct contact between the return spring 7 and the airflow. Especially during the normal air supply or backflow phase of the air duct 1, it can prevent the return spring 7 from vibrating or deforming due to airflow impact, ensuring smooth airflow and reducing the probability of dust and condensation adhering to the surface of the return spring 7.

[0048] Furthermore, since the reset spring 7 is confined within the slide groove 22, its extension and retraction trajectory is strictly constrained within the axial range of the slide groove 22, which can effectively prevent the reset spring 7 from radially shifting, bending laterally, or colliding and interfering with the main body of the second electromagnet 4 or the inner wall of the rectifier tube 2 during compression or stretching.

[0049] As a preferred embodiment of the present invention, see Figure 9 and Figure 10 As shown, the device also includes an elastic rope 17, one end of which is fixedly connected to the second electromagnet 4, and the other end of which is fixedly connected to the valve disc 61 of the one-way valve 6; when the second electromagnet 4 moves upward to a preset position, the elastic rope 17 is tightened, and the valve disc 61 of the one-way valve 6 is closed.

[0050] The one-way valve 6 originally relied solely on the air pressure at the inlet of the air duct 1 to close. The air pressure acted on one side of the valve disc 61, pushing it to adhere to the side wall of the air duct 1. If the air pressure fluctuated, such as when the air pressure was not stable when the air duct 1 was first opened, the valve disc 61 might not close tightly, resulting in a small amount of gas leaking from the rectifier pipe 2 into the air duct 1 through the one-way valve 6, interfering with the stability of the main airflow. However, when the elastic rope moves to the preset position on the second electromagnet, it tightens, actively pulling the valve disc to close through mechanical force. This forms a dual valve-closing guarantee of passive air pressure closure and active tightening of the elastic rope 17, preventing leakage and ensuring that the airflow in the air duct 1 comes only from the air inlet, without any additional interfering airflow, providing a clean and stable airflow foundation.

[0051] Furthermore, when the air duct 1 is closed, the second electromagnet 4 moves downward, and the elastic rope 17 first changes from an elastically taut state to a normally taut state, and finally sags and relaxes, releasing the tension on the valve disc 61. At this time, the air pressure inside the rectifier pipe 2 rises and can smoothly open the valve disc 61 without the elastic rope 17 hindering the opening speed of the one-way valve 6. Through the one-way linkage design of the second electromagnet 4 moving upward to tighten the valve and moving downward to relax the valve, the reliability of the closing stage is enhanced, and the opening of the valve disc 61 during the backflush stage is not interfered with, achieving functional adaptation under different operating conditions.

[0052] Furthermore, an abutment block 16 is provided in the slide groove 22. The abutment block 16 is located between the return spring 7 and the slider 41 of the second electromagnet 4, and the abutment block 16 is connected to the second electromagnet 4. One end of the elastic rope 17 is fixed to the abutment block 16.

[0053] As a preferred embodiment of the present invention, see Figure 5 As shown, the device also includes a third electromagnet 5, which is fixed to the lower inner side of the rectifier tube 2 and is located below the second electromagnet 4. The first electromagnet 3, the second electromagnet 4, and the third electromagnet 5 are configured such that when the air inlet of the air duct 1 is open, the first electromagnet 3 and the second electromagnet 4 generate an attractive force, and the second electromagnet 4 and the third electromagnet 5 generate a repulsive force, jointly driving the second electromagnet 4 to move upward along the inner side of the rectifier tube 2. When the air inlet of the air duct 1 is closed, the first electromagnet 3 and the second electromagnet 4 generate a repulsive force, driving the second electromagnet 4 to move downward along the inner side of the rectifier tube 2.

[0054] When the air duct 1 is in the open phase, the first electromagnet 3 generates an upward attractive force on the second electromagnet 4, and the third electromagnet 5 generates an upward repulsive force on the second electromagnet 4. These two forces form a bidirectional synergistic force; the attractive force provides an upward traction force, and the repulsive force provides an upward thrust force, jointly driving the second electromagnet 4 to move rapidly upward along the axial direction. Compared to a driving method that relies solely on the attractive force of the first electromagnet 3 and the energy release of the return spring 7, this combined pull and push force significantly increases the upward acceleration of the second electromagnet 4, shortening the time it takes to reach the preset position. This allows for the rapid formation of a stable negative pressure at the lower part of the rectifier tube 2, preventing the delayed establishment of negative pressure due to slow upward movement, which could lead to untimely closure of the one-way valve 6 and airflow leakage. Simultaneously, the bidirectional force acts symmetrically along the axial direction on the second electromagnet 4, offsetting any lateral force that may be generated by component processing errors or assembly deviations. This ensures that the second electromagnet 4 always moves smoothly along the central axis, avoiding increased sliding friction or uneven airflow gaps caused by tilting.

[0055] Furthermore, the magnetic force of the third electromagnet 5 can be adjusted by the magnitude of the current, giving the upward driving force of the second electromagnet 4 a customizable characteristic. For example, when the device is adapted to a large-diameter air duct 1, the current of the third electromagnet 5 can be increased to enhance the repulsive force, simultaneously increasing the upward speed and negative pressure intensity of the second electromagnet 4; when adapted to a small-diameter air duct 1, the current can be reduced to decrease the driving force and avoid energy waste.

[0056] As a preferred embodiment of the present invention, see Figure 4 and Figure 5 As shown, the reduced diameter section 21 at the upper opening of the rectifier tube 2 is provided with a plurality of pressure relief holes 23 that connect the inside and outside of the rectifier tube 2.

[0057] During the opening phase of the air duct 1, the second electromagnet 4 moves upward, compressing the air between the upper constriction section 21 of the rectifier tube 2 and the second electromagnet 4, causing the air pressure in that area to rise. Without the pressure relief hole 23, the high-pressure air would exert a reverse thrust on the second electromagnet 4, increasing the driving load on the electromagnet and potentially causing a slowdown in its upward movement or a deviation from its trajectory. The pressure relief hole 23 directly connects the inside and outside of the rectifier tube 2, quickly releasing the high-pressure air at the upper end, ensuring that the upper air pressure of the second electromagnet 4 remains close to the external atmospheric pressure during its upward movement, eliminating reverse air pressure resistance. This reduces the energy loss of the electromagnet, ensures a stable and controllable upward movement speed, and avoids a delay in negative pressure buildup due to air pressure obstruction.

[0058] As the second electromagnet 4 moves downward, the space at the upper end of the rectifier tube 2 expands, easily creating a localized negative pressure. If this negative pressure is not relieved in time, the external atmospheric pressure will exert downward pressure on the second electromagnet 4, potentially causing it to move too quickly (due to the superposition of repulsive force and gravity), or causing it to become stuck due to negative pressure adsorption. The pressure relief hole 23 can quickly replenish the upper negative pressure area with outside air, maintaining a dynamic balance between the upper air pressure and the outside environment. This ensures that the second electromagnet 4 is stably driven only by repulsive force and gravity when it moves downward, avoiding interference from vacuum resistance. Consequently, the air pressure at the lower part of the rectifier tube 2 rises evenly, causing the one-way valve 6 to open synchronously, resulting in a smoother backflow.

[0059] As a preferred embodiment of the present invention, see Figure 1 , Figure 2 and Figure 8 As shown, the device also includes a cylindrical shell 8 and a fixing plate 9 fixed inside the cylindrical shell 8, the plane of the fixing plate 9 being perpendicular to the axis of the cylindrical shell 8; a plurality of air guide pipes 1 are fixed to one side of the fixing plate 9, and a valve 10 and a driving element 11 for driving the valve 10 to open and close are connected to the air inlet of the air guide pipe 1.

[0060] In this preferred embodiment, the fixing plate 9 is perpendicular to the axis of the cylindrical shell 8, providing a unified installation plane and positioning reference for the plurality of air guide ducts 1. Compared with decentralized installation, this arrangement ensures that the axis of all air guide ducts 1 is consistent with the axis of the cylindrical shell 8, avoiding airflow direction deviation caused by installation deviation. Furthermore, the coaxial layout of multiple air guide ducts 1 allows the output to be superimposed or diffused in the same direction, forming a multi-coordinated air supply effect, improving the uniformity of air supply in large spaces, and avoiding local air supply dead zones.

[0061] The cylindrical shell 8 encloses the air duct 1, the fixing plate 9, the valve 10, and the driving element 11. On the one hand, it can isolate external dust, moisture, and mechanical collisions, protect the internal precision components, and reduce failures caused by environmental factors, such as one-way valve jamming caused by dust accumulation and poor contact of electromagnets. On the other hand, the cylindrical shell 8 can serve as a unified airflow channel, guiding the concentrated outward delivery of the air duct 1, avoiding disorderly diffusion of airflow in the agricultural greenhouse, and improving air delivery efficiency.

[0062] The drive element 11 (such as an electromagnetic driver or a micro motor) directly controls the opening and closing of the valve 10. Compared with traditional manual valves or valves driven by pneumatic pressure, it has a faster opening and closing speed and can realize the synchronous action of multiple valves 10 through electronic control signals. When the drive element 11 receives a signal to open the valve 10, it can simultaneously trigger the first electromagnet 3, the second electromagnet 4, and the third electromagnet 5 to be energized, driving the second electromagnet 4 to move upward; when the valve is closed, it simultaneously triggers the third electromagnet 5 to be de-energized and the first electromagnet 3 to switch its repulsive force, ensuring that the timing of valve opening and closing, electromagnet movement, and the state of the one-way valve 6 is without deviation, avoiding airflow turbulence caused by valve action lag.

[0063] See Figure 1 and Figure 8 As shown, there are four air ducts 1, which are connected in a rectangular shape to one side of the fixing plate 9. See also Figure 7 As shown, the valve 10 includes a valve body and shielding portions located at both ends of the valve body that are adapted to the shape of the air inlet of the air duct 1. The valve body is attached to the surface of the fixing plate 9 facing away from the air duct 1. The driving element 11 is a motor, which is fixed inside the cylindrical housing 8 by a rod. The output shaft of the motor is connected to the valve body for transmission. The rotation of the motor drives the valve body to rotate, thereby opening or closing the air inlet of the air duct 1.

[0064] As a preferred embodiment of the present invention, see Figure 1 and Figure 2 As shown, it also includes a mounting plate 12 fixed inside the cylindrical housing 8, and a plurality of air intake fans 13 corresponding to the positions of the air duct 1 are fixed on the mounting plate 12.

[0065] In this preferred embodiment, the intake fan 13 is positioned one-to-one with the air duct 1, and can actively provide a stable airflow to the air duct 1. At the same time, the intake fan 13 can pre-filter impurities (such as dust and water vapor) in the airflow through auxiliary structures such as filters, to prevent impurities from entering the air duct 1 and adhering to the one-way valve 6 or the electromagnet, thus affecting the operating accuracy of the components.

[0066] Each inlet fan 13 corresponds to only one air duct 1, and its speed can be adjusted individually according to parameters such as the diameter and length of the air duct 1 to ensure that the delivered air volume is precisely matched with the airflow handling capacity of the air duct 1. Compared with a single large fan supplying air to multiple air ducts 1, the one-to-one design allows each air duct 1 to receive uniform airflow input, ensuring consistent quality when multiple air ducts 1 are running simultaneously.

[0067] As a preferred embodiment of the present invention, see Figure 3 As shown, the lower end of the air duct 1 is connected to a tapered pipe 14, and the large-diameter end of the tapered pipe 14 is connected to the air outlet at the lower end of the air duct 1.

[0068] In this preferred embodiment, the tapered tube 14's gradient structure guides the airflow to form a convergence-release dynamic process at the outlet. That is, the airflow gradually converges towards the center along the inner wall of the tapered tube 14, forming a concentrated airflow stream at the end outlet. At this point, the circumferential rotational momentum of the airflow is more easily concentrated, resulting in stronger closure. Compared to the divergent airflow at a straight outlet, this concentrated airflow stream better maintains the annular structure, reduces mixing with surrounding air, thereby reducing the diffusion velocity and extending the effective air delivery distance.

[0069] The ventilation device for agricultural greenhouses described in this invention achieves efficient and stable air delivery through the coordinated operation of its core components. The specific workflow is as follows:

[0070] Initial air intake stage: See Figure 2 As shown, after the device is started, the intake fan 13 runs first, continuously drawing in outside air and sending it into the cylindrical shell 8, providing a basic air source for subsequent airflow regulation.

[0071] Air intake control stage: The core component, the drive motor, i.e. the drive element 11, outputs power and drives the valve 10 to rotate through the transmission shaft. Since the rotation trajectory of the valve 10 corresponds to the four air ducts 1, the valve 10 will periodically switch between opening and closing the four air ducts 1 to achieve intermittent airflow delivery control.

[0072] See Figure 9 As shown, when valve 10 is rotated to the open position of air duct 1, that is, when the air inlet of air duct 1 is not blocked, the device enters the following linkage state: the first electromagnet 3, the second electromagnet 4, and the third electromagnet 5 in the rectifier tube 2 are all energized. The third electromagnet 5 generates a repulsive force on the second electromagnet 4, and the first electromagnet 3 generates an attractive force on the second electromagnet 4. The combined force of the two drives the second electromagnet 4 to move upward along the inner side of the rectifier tube 2. Because the contact block 16 is pressed by the slider 41 outside the second electromagnet 4, and the contact block 16 is connected to the valve disc 61 of the one-way valve 6 through the elastic rope 17, when the second electromagnet 4 moves upward, the contact block 16 will move upward under the action of the return spring 7. When it reaches the preset position, the elastic rope is straightened, so that the upward pulling force of the contact block 16 causes the valve disc 61 to rotate around the valve body of the one-way valve 6, ultimately assisting in the closure of the one-way valve 6. In this state, the one-way valve 6 will not interfere with the airflow in the air duct 1, ensuring that the airflow passes smoothly through the air duct. Furthermore, the second electromagnet 4 continues to move upward under the above-mentioned force. During its movement, a negative pressure area will be formed inside the rectifier tube 2, preparing for the subsequent airflow backflow. At the same time, the elastic rope 17 changes from a normally taut state to an elastically stretched state.

[0073] When valve 10 rotates to the closed position of air duct 1, that is, when the air inlet of air duct 1 is completely blocked, the device switches to the following linkage state. The core objective is to quickly smooth the residual airflow in the air duct and shorten the sealing time of air duct 10 by valve 10: The third electromagnet 5 is de-energized, and the first electromagnet 3 and the second electromagnet 4 are energized. After being energized, they generate opposite magnetic fields, that is, they repel each other. Under the triple action of the repulsive force of the first electromagnet 3, the gravity of the second electromagnet 4, and the attraction of the negative pressure at the bottom of the rectifier tube 2, the second electromagnet 4 moves rapidly downward along the inner side of the rectifier tube 2. When the second electromagnet 4 moves rapidly downward, it will act on the return spring 7 through the abutment block 16, so that the return spring 7 will naturally release its stretched energy, providing auxiliary power for the downward movement of the second electromagnet 4. At the same time, the elastic rope 17 changes from elastic taut to a pliable state without elastic force, so that the one-way valve 6 opens under the action of air pressure and gravity. On the one hand, the downward movement of the second electromagnet 4 will force the air in the rectifier tube 2 to be squeezed from the one-way valve 6 into the air duct 1, which will have a backlash effect on the turbulent airflow remaining in the air duct 1 and accelerate the calming of the airflow. On the other hand, the opened valve 61 will directly generate additional resistance to the airflow flowing in the air duct 1, further shortening the airflow calming time, thereby reducing the required closure and stabilization time of the air duct 1.

[0074] Among them, there are five one-way valves 6, which are evenly distributed along the outside of the air duct 1, ensuring that the backflow airflow and resistance effect evenly cover the entire area inside the air duct, so as to achieve rapid, uniform and calm airflow.

[0075] Through the cyclical opening (airflow delivery, negative pressure energy storage) and closing (airflow backflow, rapid calming) of air duct 1, air duct 1 can continuously output a stable and uniform airflow. Due to the shortened airflow calming time and improved air delivery efficiency, the device ultimately achieves a longer air delivery distance and higher airflow stability.

[0076] In one embodiment, the present invention provides an air supply control system, the system comprising:

[0077] The control module is used to receive external commands (such as air supply mode, frequency requirements, etc.) and send operation signals to the drive element 11.

[0078] The power supply module is used to provide stable power to the drive element 11, the first electromagnet 3, the second electromagnet 4 and the third electromagnet 5.

[0079] The encoder is used to monitor the rotation speed of the drive element 11 in real time when the drive element 11 is running, and feed the data back to the control module and the H-bridge drive circuit module to form a closed-loop control, ensuring that the drive element 11 drives the valve 10 to rotate at a precise rhythm, thereby accurately controlling the timing and duration of the opening or closing of the air duct.

[0080] The H-bridge drive circuit module is used to receive commands from the control module and the operating status of the drive element 11 fed back by the encoder, dynamically adjust the on / off state and current magnitude of the first electromagnet 3, the second electromagnet 4, and the third electromagnet 5, and thus precisely control the magnetic field interaction between the electromagnets to achieve intelligent linkage of the rectifier mechanism.

[0081] When the air duct 1 is opened, the H-bridge drive circuit module controls the first electromagnet 3, the second electromagnet 4, and the third electromagnet 5 to be energized, so that the first electromagnet 3 generates an attractive force on the second electromagnet 4 and the third electromagnet 5 generates a repulsive force on the second electromagnet 4. Combined with the elastic force of the reset spring 7, the second electromagnet 4 is driven to move upward, and the one-way valve 6 is closed simultaneously, forming a negative pressure in the rectifier tube 2.

[0082] When the air duct 1 is closed, the H-bridge drive circuit module is adjusted to only energize the first electromagnet 3 and the second electromagnet 4, while de-energizing the third electromagnet 5. A repulsive force is generated between the first electromagnet 3 and the second electromagnet 4, causing the second electromagnet 4 to move rapidly downward under the action of magnetic field repulsion, its own gravity, and the air pressure at the bottom of the rectifier tube 2. Simultaneously, the one-way valve 6 is opened, realizing airflow backflow and rapid calming of the airflow in the air duct 1.

[0083] Based on the above control circuit, the control module can dynamically adjust according to different air supply requirements, such as high / low wind speed and air supply frequency.

[0084] The speed of the drive motor is adjusted to change the rotation cycle of valve 10 and regulate the opening and closing frequency of the air duct.

[0085] The magnitude of the current in the electromagnet is adjusted to change the strength of the magnetic field, thereby regulating the moving speed and stroke of the second electromagnet 4 and optimizing the rectification effect.

[0086] This enables intelligent adaptation of air delivery efficiency, air delivery distance, and stability to meet the air delivery needs of diverse scenarios.

[0087] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A ventilation device for agricultural greenhouses, characterized in that: It includes a duct (1), a rectifier tube (2) sleeved outside the duct (1), and a first electromagnet (3) and a second electromagnet (4) connected to the inner wall of the rectifier tube (2). Multiple one-way valves (6) connecting the inside and outside of the duct (1) are evenly arranged in the lower part of the side wall of the duct (1). When the one-way valve (6) is opened, the gas in the rectifier tube (2) enters the duct (1) through the one-way valve (6). The rectifier tube (2) has radially inwardly extending reduced diameter sections (21) at both ends, and the inner side of the reduced diameter section (21) is sealed to the outer side of the air guide tube (1). The first electromagnet (3) is fixedly connected to the upper part of the inner side of the rectifier tube (2), and the second electromagnet (4) is located below the first electromagnet (3); The outer side of the second electromagnet (4) is slidably connected to the inner side of the rectifier tube (2), and the inner side of the second electromagnet (4) is slidably and gapably connected to the outer side of the air duct (1); A reset spring (7) is connected between the second electromagnet (4) and the rectifier tube (2).

2. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: The first electromagnet (3) is fixed on the lower side of the reduced diameter section (21) at the upper end opening of the rectifier tube (2), and the reset spring (7) is connected between the second electromagnet (4) and the reduced diameter section (21) at the lower end opening of the rectifier tube (2).

3. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: The second electromagnet (4) has at least one groove (22) extending axially along the rectifier tube (2) on one of its outer side and the inner side of the rectifier tube (2), and the other has a slider (41) adapted to the groove (22).

4. The ventilation device for agricultural greenhouses according to claim 3, characterized in that: The inner side of the rectifier tube (2) is provided with at least one groove (22) extending along the axial direction of the rectifier tube (2), and the outer side of the second electromagnet (4) is provided with a slider (41) that is adapted to the groove (22). The reset spring (7) is positioned within the slide groove (22). The upper end of the reset spring (7) is fixedly connected to the lower side of the slider (41) of the second electromagnet (4), and the lower end of the reset spring (7) is fixedly connected to the lower wall of the slide groove (22).

5. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: It also includes an elastic rope (17), one end of which is fixedly connected to the second electromagnet (4), and the other end of which is fixedly connected to the valve disc (61) of the one-way valve (6); when the second electromagnet (4) moves upward to the preset position, the elastic rope (17) is tightened, and the valve disc (61) of the auxiliary one-way valve (6) is closed.

6. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: It also includes a third electromagnet (5), which is fixed to the lower inner side of the rectifier tube (2) and is located below the second electromagnet (4); The first electromagnet (3), the second electromagnet (4), and the third electromagnet (5) are configured such that when the air inlet of the air duct (1) is opened, the first electromagnet (3) and the second electromagnet (4) generate an attractive force, and the second electromagnet (4) and the third electromagnet (5) generate a repulsive force, which together drive the second electromagnet (4) to move upward along the inner side of the rectifier tube (2). When the air inlet of the air duct (1) is closed, a repulsive force is generated between the first electromagnet (3) and the second electromagnet (4), driving the second electromagnet (4) to move downward along the inside of the rectifier tube (2).

7. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: The reduced diameter section (21) at the upper opening of the rectifier tube (2) is provided with several pressure relief holes (23) that connect the inside and outside of the rectifier tube (2).

8. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: It also includes a cylindrical shell (8) and a fixing plate (9) fixed inside the cylindrical shell (8), wherein the plane of the fixing plate (9) is perpendicular to the axis of the cylindrical shell (8); Several air ducts (1) are fixed to one side of the fixed plate (9). The air inlet of the air duct (1) is connected to a valve (10) and a driving element (11) for driving the valve (10) to open and close.

9. The ventilation device for agricultural greenhouses according to claim 8, characterized in that: It also includes a mounting plate (12) fixed inside the cylindrical shell (8), and a plurality of air intake fans (13) corresponding to the positions of the air duct (1) are fixed on the mounting plate (12).

10. The ventilation device for agricultural greenhouses according to claim 1, characterized in that: The lower end of the air duct (1) is connected to a tapered pipe (14), and the large-diameter end of the tapered pipe (14) is connected to the air outlet at the lower end of the air duct (1).

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