Pressure compensation type underground drip irrigation head and drip irrigation pressure high uniformity control method

Abstract

A pressure compensation type underground drip irrigation head comprises a main body part, a turn-back assembly and a spiral assembly, the turn-back assembly is arranged in a first hole cavity of a first main body, and the turn-back assembly comprises a plurality of overflowing annular plates and flow baffles which are alternately stacked, so that a turn-back flow channel is formed between the turn-back assembly and the first main body; the spiral assembly is arranged in the second hole cavity of the second main body and comprises a spiral groove, and a pressure regulating flow channel is formed between the spiral groove and the second main body; when the second main body is hermetically jointed with the first main body, the first hole cavity is communicated with the second hole cavity to form a drip irrigation cavity, and the return runner is communicated with the pressure regulating runner in series, so that the pressure uniformity is easily and quickly regulated.

Description

Technical Field

[0001] The present invention relates to the technical field of drip irrigation, and in particular to a pressure-compensating underground drip irrigation head and a method for controlling high-uniformity of drip irrigation pressure. Background Art

[0002] Drip irrigation heads do not spray water onto crop fields. Instead, they deliver water drop by drop near the roots, slowly discharging it at a rate of 2-6 L / h. The water drips directly onto the root zone of specific plants through the small-volume water outlet of the drip irrigation head. Underground drip irrigation, which integrates water and fertilizer, typically requires drop-by-drop irrigation technology. This involves multiple drip irrigation heads installed at intervals on a main drip irrigation line and buried underground. The main drip irrigation line is connected to a pressurized water source, providing a pressure of, for example, 60-130 kPa. Controlling pressure uniformity is a key technology. Existing drip irrigation lines suffer from the following technical drawbacks.

[0003] (1) Uneven dripping uniformity

[0004] Controlling flow to ensure a stable supply of relatively small volumes is no simple task. A drip irrigation main line, over 60 meters long, has multiple drip heads spaced along its axis. Testing has shown that the water pressure at the proximal end of the main line, close to the water source, is greater than at the distal end. The water pressure gradually decreases along the line toward the distal end, where the water flow terminates. Because the drip rate of a drip head is a function of water pressure, the drip rate at the proximal end of the main line is necessarily greater than at the distal end. Therefore, the drip rate at the last drip head along the main line decreases accordingly due to the reduced water pressure reaching that point. If uniform output from each drip head is desired, the output flow channel cross-section of the drip head must be adjusted accordingly based on the pressure drop. A major drawback of the existing technology is how to conveniently adjust the drip uniformity of a large number of drip heads.

[0005] (2) During drip irrigation, the drip irrigation head is prone to clogging

[0006] Drip heads are often designed as pistons, with positive pressure drip irrigation and negative pressure sealing the discharge holes without sealing the drip holes. Regardless of the intricacy of the design, soil, sand, and other impurities can completely block the drip holes, preventing the head from discharging water and fertilizer, even with positive pressure within the drip chamber. Developing drip heads that can function correctly over time is a primary priority. Shanghai Yinneng Energy Saving and Environmental Protection Technology Co., Ltd. has developed an internally embedded anti-filter, anti-clogging emitter and drip irrigation pipeline (CN102671782A, published on September 19, 2012). The first pipe member 21 is coaxially inserted into the second pipe member 22. The top ring 224 of the second pipe member and the inner step of the first pipe member sandwich an annular filter cloth 23. The first pipe column is equipped with an inner ring platform and an annular groove. The inner ring platform is provided with eight seepage holes 215. The density of the geotextile 23 can be adjusted by the gap between the top ring 224 of the second pipe column and the inner ring protrusion of the seepage hole 215. The inner hole 213 of the first pipe 21 forms a water diversion channel connected to the water supply flow. The exposed geotextile 23, seepage holes 223 and depressions together constitute the outlet channel. The seepage holes 215 are the only water seepage medium. Water can only seep out of the seepage holes 215 after passing through the water diversion channel, filter cloth and outlet channel in sequence. The seepage holes 215 are inside the annular groove and are hidden. Moreover, the filter cloth such as the geotextile is flexible, so it will not be completely blocked. It can prevent physical blockage, chemical blockage and biological blockage, and has a wide range of applications. The design of the seepage hole 215 of this drip irrigation head is very clever, but the pressure chambers of the water inlet channel and the water outlet channel in the drip irrigation head are almost non-existent. The absence of a pressure chamber is more likely to sensitively respond to pressure changes in the pipeline system. When the direction of liquid circulation in the drip irrigation chamber is reversed, suction is easily generated at the output port, which causes sand and soil particles to penetrate into the drip irrigation head, making it unusable.

[0007] In summary, the field urgently needs an underground drip irrigation device with high drip uniformity, simple and easy uniformity debugging, and the ability to work correctly for a long time without being easily blocked. This is a technical problem that urgently needs to be solved in the field of drip irrigation devices. Summary of the Invention

[0008] In view of the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a pressure-compensated underground drip irrigation head and a control method for high uniformity of drip irrigation pressure, so as to solve the technical problems of "high drip uniformity, simple and easy uniformity debugging, long-term correct operation and not easy to clog".

[0009] The purpose of the present invention is to achieve the following: a pressure-compensated underground drip irrigation head comprising

[0010] The main body comprises a first main body and a second main body, wherein the first main body is provided with a first cavity and the second main body is provided with a second cavity;

[0011] A foldback assembly is provided in the first cavity of the first body, and the foldback assembly includes a plurality of alternately stacked flow ring plates and baffle plates, so that a foldback flow channel is formed between the foldback assembly and the first body;

[0012] A spiral assembly is provided in the second cavity of the second body, the spiral assembly includes a spiral groove, and a pressure regulating flow channel is formed between the spiral groove and the second body;

[0013] When the second body is sealed and connected to the first body, the first cavity is connected to the second cavity to form a drip irrigation cavity, and the return flow channel is connected in series to the pressure regulating flow channel.

[0014] Furthermore, the first body is provided with a water inlet at the head end and an open end at the tail end; the second body is provided with a water outlet at the tail end and an open end at the head end; the first body and the second body are coaxial and the open ends are sealed and joined facing each other to form the drip irrigation chamber, and a return flow channel is formed in the drip irrigation chamber in series with a pressure regulating flow channel and a first pressure reducing channel arranged successively along the axial direction.

[0015] Furthermore, the second body also includes an internal screw component, which includes internal screw ridges provided on the inner wall of the second body, and internal spiral grooves are formed between the internal screw ridges; a connecting channel is provided on the outer wall of the first body along the axial direction; the open ends of the first body and the second body are inserted into the second body facing each other or in the same direction until they abut and seal to form a drip irrigation chamber, so that a spiral additional flow channel is formed between the first body and the second body, and at the same time, the connecting channel connects the additional flow channel with the return flow channel located in the first body, and a second pressure reduction channel is formed in the drip irrigation chamber with the return flow channel embedded in the radial direction of the additional flow channel at the same axial position.

[0016] Furthermore, the first cavity includes a base cavity and side concave cavities symmetrically arranged on both sides of the base cavity and connected thereto, N flow ring plates are stacked with N baffle plates, and the baffle plates alternately abut the side concave cavities on both sides to form N-1 return diverter channels that are connected end to end with opposite flow directions and connected end to end; an N+1 flow ring plate is provided on the back of the Nth baffle plate for abutting the second main body, and the N+1th flow ring plate abuts on the second main body to form the Nth return diverter channel.

[0017] Furthermore, the flow ring plate includes a plurality of first spacer columns and a second spacer column spaced apart on the closed-loop belt body at intervals of the opposite side concave cavities, and a plurality of support ribs arranged in parallel and at intervals between the first spacer columns and the second spacer columns. The support ribs alternately abut against the base cavity, so that a secondary return channel is formed in the return diversion channel.

[0018] Furthermore, the spiral assembly includes a sleeve body, the sleeve body is provided with external spiral ridges, and spiral grooves are formed between the external spiral ridges. The sleeve body is inserted into the second body. When a spiral pressure-regulating channel is formed on the inner walls of the sleeve body and the second body, the pressure ring sleeve is threadedly engaged with the second body to coaxially press the sleeve body therein.

[0019] Furthermore, a series of sleeve bodies is included, and the series includes a series of turns with the same groove width but different numbers of turns and a series of grooves with the same number of turns but different groove widths.

[0020] Furthermore, it also includes an anti-backflow mechanism arranged at the water inlet, which includes a plug, a U-shaped elastic arm and a fixed arm connected in sequence. The water inlet is provided with a plug pit, the plug is fitted in the plug pit, and the fixed arm is fixedly arranged beside the water inlet.

[0021] Furthermore, the second main body or the water outlet portion includes a stepped cylinder portion, and a spiral component is provided in the stepped cylinder portion, so that the pressure regulating flow channel is formed between the inner wall of the stepped cylinder portion and the spiral component.

[0022] A method for controlling the high uniformity of the drip irrigation pressure of the pressure-compensated underground drip irrigation head,

[0023] S1. Arrange drip irrigation pipes and build up the water head pressure of the drip irrigation pipes;

[0024] S2. Determine the minimum working pressure P at the highest position on the ground with the maximum radius 工 ;

[0025] S3. Adjust the maximum radius R max Adjust the working pressure of other drip irrigation heads to the minimum working pressure P 工 ; R i =R max -Gap, Gap is the arrangement radius interval of the drip irrigation head;

[0026] S4. With radius R i , find the drip irrigation head at the highest position on the ground, and adjust the working pressure of the drip irrigation head to close to the minimum working pressure P 工 ;

[0027] S5. Adjust the same radius R i Other drip irrigation heads at working pressure P 工 ;

[0028] S6.R i =R i -Gap; if R i >2m, go to step S4; if R i ≤2m, go to step S7;

[0029] S7. End the voltage regulation work.

[0030] Compared to existing pressure-compensating drippers, the pressure-compensating underground drip irrigation head and method for controlling high drip irrigation pressure uniformity disclosed herein provide an acceptable output uniformity over a significantly wider input pressure range. Specifically, through different combinations of return and spiral assemblies, the flow path is increased without increasing the overall length of the drip irrigation head, accommodating higher drip irrigation pressures. Furthermore, by adjusting the pressure uniformity through a series of spiral assemblies tailored to the number of spiral turns and the width of the spiral groove, the system is easier and more quickly adjusted, making it more suitable for the installation and commissioning of large numbers of drip irrigation heads. This makes it simple and feasible, and highly valuable for widespread application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a front view of Example 1 of a pressure-compensated underground drip irrigation head of the present invention;

[0032] Figure 2 This is a pressure compensation underground drip irrigation head of embodiment 1 of the present invention. Figure 1 AA section view;

[0033] Figure 3 This is a front view of a pressure-compensating underground drip irrigation head according to embodiment 1 of the present invention, which uses a pressure-regulating flow channel with multiple turns.

[0034] Figure 4 This is a schematic diagram of Example 1 of a pressure-compensating underground drip irrigation head of the present invention, in which the main line pressure is greater than the minimum working pressure (before debugging).

[0035] Figure 5 This is a schematic diagram of Example 1 of a pressure-compensating underground drip irrigation head of the present invention, in which the main line pressure is greater than the minimum working pressure (after debugging).

[0036] Figure 6 This is a main cross-sectional view of Example 2 of a pressure-compensating underground drip irrigation head of the present invention.

[0037] Figure 7 This is a main cross-sectional view of another implementation example of embodiment 2 of a pressure-compensating underground drip irrigation head of the present invention;

[0038] Figure 8 This is a main cross-sectional view of Example 3 of a pressure-compensating underground drip irrigation head of the present invention;

[0039] Figure 9 This is a pressure compensation underground drip irrigation head of the present invention. Figure 8 BB cross-sectional view;

[0040] Figure 10 This is a main cross-sectional view of a drip irrigation chamber of Example 4 of a pressure-compensating underground drip irrigation head of the present invention in a positive pressure state.

[0041] Figure 11 This is a main cross-sectional view of a drip irrigation chamber of Example 4 of a pressure-compensating underground drip irrigation head of the present invention in a negative pressure state.

[0042] Reference numerals in the above figures:

[0043] 10 Main body, 11 First main body, 12 Second main body, 13 Drip irrigation chamber, 14 First hole cavity, 15 Second hole cavity, 16 First pressure-reducing channel, 17 Second pressure-reducing channel, 18 Vibrating rib, 14.1 Base cavity, 14.2 Side concave cavity, 20 Reversing assembly, 21 Reversing channel, 22 Flow ring plate, 23 Baffle, 24 Closed-loop belt, 25 Spacer, 26 Reversing flow channel, 27 Secondary reversing channel, 28 Support rib, 29 Buffer chamber, 23.1 Base main plate, 23.2 Side convex plate, 25.1 First spacer, 25.2 Second spacer, 30 Spiral assembly, 31 Pressure-regulating channel, 32 Spiral groove, 33 Sleeve body, 34 Positioning protrusion, 35 Pressing ring, 36 External screw flight, 37 Additional flow channel, 38 Connecting channel, 39 Stepped cylinder, 40 water inlet, 41 annular cover, 42 supporting protrusion, 50 water outlet, 51 filter, 60 pressure measuring assembly, 61 pressure measuring housing, 62 piston, 63 pressure measuring air chamber, 64 liquid chamber, 65 pressure regulating scale, P0 zero position, 70 anti-return mechanism, 71 plug, 72 U-shaped elastic arm, 73 fixed arm, 80 internal screw assembly, 81 additional flow channel, 82 internal screw ridge, 83 internal spiral groove. DETAILED DESCRIPTION

[0044] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but are not intended to limit the scope of the present invention.

[0045] Example 1

[0046] Concept: return flow channel + pressure regulating flow channel, the length of the pressure regulating flow channel is adjusted to deal with the high and low water inlet pressure.

[0047] A pressure-compensated underground drip irrigation head, comprising

[0048] The main body 10 includes a first main body 11 and a second main body 12 . The first main body 11 is provided with a first cavity 14 , and the second main body 12 is provided with a second cavity 15 .

[0049] The folding assembly 20 is disposed in the first cavity 14 of the first body 11. The folding assembly 20 includes a plurality of alternately stacked flow ring plates 22 and baffle plates 23, so that a folding flow channel 21 is formed between the folding assembly 20 and the first body 11.

[0050] The spiral assembly 30 is disposed in the second cavity 15 of the second body 12. The spiral assembly 30 includes a spiral groove 32. A pressure regulating channel 31 is formed between the spiral groove 32 and the second body 12.

[0051] When the second body 12 is sealed and joined to the first body 11 , the first cavity 14 is connected to the second cavity 15 to form the drip irrigation cavity 13 , and the return flow channel 21 is connected in series to the pressure regulating flow channel 31 .

[0052] The specific structure of the return flow channel 21 is described below. The first cavity 14 includes a base cavity 14.1 and side concave cavities 14.2 symmetrically arranged on both sides of the base cavity and connected thereto. The cross-section of the base cavity 14.1 can be a closed curve, such as a circle or an ellipse, or a polygon, such as a rectangle or a square. The flow ring plate 22 includes a closed loop belt body 24 and a plurality of spacer columns 25 spaced apart from each other on the closed loop belt body 24. The baffle 23 includes a base main plate 23.1, on which a side convex portion 23.2 corresponding to the side concave cavity is provided axially symmetrically with respect to the maximum diameter on one side of the maximum diameter. N flow ring plates 22 are stacked on N baffle plates 23, and the side convex portions 23.2 of the baffle plates 23 are alternately abutted against the side concave cavities 14.2 on both sides to form N-1 return flow channels 26 connected end to end and with opposite flow directions. An N+1th flow ring plate 22 is disposed behind the Nth baffle plate 23, configured to abut against the second body 12. This abutment of the N+1th flow ring plate 22 on the second body 12 forms the Nth return flow channel 26. The N+1th flow ring plate 22 communicates with the second cavity 15 through the inner aperture of the annular body 24. To enhance the seal between the first cavity 14 and the baffle plate 23, the first body 11 may include a plastic layer and a rubber layer, with the rubber layer positioned on the inner wall of the first cavity 14.

[0053] The specific structure of the spiral assembly 30. The spiral assembly 30 includes a sleeve body 33, which is provided with an external screw rib 36 and an internal positioning hole. A spiral groove 32 is formed between the external screw ribs 36. The sleeve body 33 is closed at one end and provided with an internal positioning hole extending along the other end. A positioning protrusion 34 is provided at the bottom of the second cavity 15 of the second body 12. The sleeve body 33 is inserted into the second body 12. When the inner walls of the sleeve body and the second body form a spiral pressure-regulating flow channel 31, the sleeve body 33 is inserted into the positioning protrusion 34 through the internal positioning hole 32 and is coaxially arranged in the second body 12. It also includes a pressure ring sleeve 35, which is threadedly engaged with the second body 12 to press the sleeve body 33 against the positioning protrusion 34. The positioning protrusion 34 is connected to the water outlet portion 50 through a plurality of connecting holes 35. The water outlet portion 50 is provided with a filter 51.

[0054] The first body 11 has an inlet 40 at its front end and an open end at its rear end. The second body 12 has an outlet 50 at its rear end and an open end at its front end. The first and second bodies 12 are coaxial and sealed together with their open ends facing each other to form a drip irrigation chamber 13. Within the drip irrigation chamber 13, a return channel is formed, which is connected in series with a pressure-regulating channel and a first pressure-reducing channel 16 arranged sequentially along the axial direction. A buffer chamber 29 is formed between the return channel 21 and the pressure-regulating channel 31. The main water flow enters the drip irrigation head from the inlet 40, passes through the return channel 21, the buffer chamber 29, and the pressure-regulating channel 31, and then exits the drip irrigation head through the outlet 50 for drip irrigation of the surrounding plants. A first method of sealing is a threaded connection. For example, the open end of the second body 12 has an internal thread, and the open end of the first body 11 has an external thread. A sealing gasket is incorporated into the internal thread, and the gasket is screwed together with the external thread so that the first body abuts against the sealing gasket for a seal. The second sealing method is ultrasonic welding. The open end of the first body 11 is provided with a vibration rib 18, and the second body 12 is arranged on an ultrasonic generator. The open end of the second body 12 is ultrasonically welded to the open end of the first body 11, and the vibration rib 18 becomes a welding sealing material.

[0055] Compensation for changes in water inlet pressure: The pressure is adjusted according to the size of the water inlet pressure by combining the number of spirals with the width of the spiral groove.

[0056] The number of spiral turns adjusts the pressure, adjusting the water pressure accordingly. Specifically, the spiral assembly 30 includes a series of spiral sleeves 33: a series Q1 of spiral sleeves 33 with the same groove width but different numbers of turns, and a series Q2 of spiral sleeves 33 with the same number of turns but different groove widths. Drip heads with different radii can be adjusted using the series Q1, while drip heads with the same radius can be adjusted using the series Q2. More preferably, the system also includes a series Q3 of cones with the same groove width and number of turns, including tapers of 1°, 3°, 5°, and 7°. The greater the taper, the greater the reduction in the volume of the spiral groove.

[0057] The number of turns can be listed as follows: decreasing by two turns each time, such as 12 turns, 10 turns, 8 turns, 6 turns, and 4 turns. The number of turns of the spiral groove 31 provided on the outer surface of the sleeve body 33 compensates for the change in the water pressure. The greater the water pressure, the more turns, and the smaller the water pressure, the fewer turns.

[0058] Under the premise of the same number of spirals, the pressure can be further accurately adjusted by the spiral width. The maximum width w=2, and the series sleeve bodies with widths of 2mm, 1.5mm, 1mm, and 0.8mm are each provided, decreasing by two turns each time. Assuming the maximum number of turns C=12, such as 12 turns, 10 turns, 8 turns, 6 turns, and 4 turns. For example, it has been determined that a 6-turn pressure regulating flow channel is required at this position. After screwing in a spiral sleeve with a spiral groove width of 2mm and 6 turns, the pressure reduction effect is still poor, and the drip irrigation volume is large. Then, it is replaced with a 6-turn spiral with widths of 1.5mm, 1mm, and 0.8mm to further reduce the drip irrigation volume to close to the reference drip irrigation volume. Figure 3 The spiral sleeve 33 shown has 6 spiral turns, and Figure 1 The spiral sleeve 33 shown has four spiral turns.

[0059] The spiral diameter of the pressure regulating channel 31 is less than or equal to 1 / 2 of the diameter of the first inner hole 14 of the first body 11. Specifically, the spiral diameter of the pressure regulating channel 31 can be selected between 10-30 mm.

[0060] like Figure 4 As shown, it also includes a pressure measuring assembly 60 for measuring the water pressure at the end of the pressure regulating channel 31 and displaying the lowest water pressure position as a reference water pressure. The pressure measuring assembly 60 includes a transparent pressure measuring housing 61 and a piston 62. The pressure measuring housing 61 is arranged outside the second body 12 to form a pressure measuring cavity. A piston 62 is slidably arranged in the pressure measuring cavity, so that one side of the piston 62 is a pressure measuring air cavity 63 and the other side is a liquid cavity 64 connected to the downstream of the pressure regulating channel 31. Usually, the lowest working pressure P 工 The piston 62 of the drip irrigation head is moved to the zero position P0 at the rightmost end of the pressure measuring chamber by adjusting the air pressure (such as Figure 4 The zero position P0 is the reference water pressure of the drip irrigation chamber 13. The pressure measuring housing 61 is provided with a pressure adjustment scale 65. The pressure adjustment scale has an accuracy of 0.1m for the water head pressure representing the integer m and the decimal point. When adjusting the pressure, a uniformity requirement of less than 10% is satisfied if the zero position P0 is within plus or minus one scale.

[0061] Before installing and debugging other drip irrigation heads, use the minimum working pressure P 工 The air is charged into the pressure measuring air chamber 63. Since the pressure of the drip irrigation chamber of other drip irrigation heads is not necessarily equal to the minimum working pressure P 工 Therefore, the position of the piston 62 is not necessarily at the zero position P0. During debugging, the required number of turns of the spiral assembly 30 is determined based on the distance the piston is away from the zero position, and then the spiral width is determined. Until the piston position returns to the zero position, it indicates that the isobaric adjustment of the drip irrigation head is completed.

[0062] A method for controlling high uniformity of drip irrigation pressure comprises the following steps:

[0063] S1: Arrange the drip irrigation mains and establish the water head pressure. For example, in a gravity-fed drip irrigation system, the water head pressure of the drip irrigation mains is typically 8-12 m. The drip irrigation tank is located in the center of the plot. Build the drip irrigation system, install the drip irrigation mains and branch pipes, and install the drip heads on the branch pipes. Start the drip irrigation system and begin pressure regulation.

[0064] S2 The lowest working pressure P is determined at the farthest distance and the highest position on the ground 工 .

[0065] For example, if we consider a circular plot, the maximum distance is equal to the maximum radius. With the drip irrigation tank as the center, find the highest point on the ground and the drip irrigation head with the lowest operating pressure. Install it with a spiral assembly with a certain number of turns and a maximum groove width of 2mm. Use the side pressure assembly 60 to adjust the piston to the zero position P0.

[0066] If we take a rectangular plot as an example, the intersection of the diagonals of the rectangle, that is, the midpoint O of the rectangle, is the location of the water tank. A main line is set along the length direction through the midpoint O, and a branch line connected to the main line is set every 1m parallel to the short side. The maximum distance is equal to the farthest point from the water tank along the length direction. Minimum working pressure P 工 The water pressure at the highest ground level and furthest from the tank in the longitudinal direction.

[0067] This water pressure is taken as the minimum working pressure P 工 , adjust the water pressure of other drip irrigation heads to be equal to the minimum working pressure P 工 .

[0068] S3. Adjust the maximum distance L max Adjust the working pressure of other drip irrigation heads to the minimum working pressure P 工 .

[0069] For the same maximum distance L max For other drip irrigation heads, select spiral sleeves with the same number of turns and different spiral groove widths to adjust the working pressure of other drip irrigation heads to the minimum working pressure P 工 .

[0070] Then L i =L max -Gap, Gap is the layout radius interval of the drip irrigation head (unit: m);

[0071] S4. At distance L i , find the drip irrigation head at the highest position on the ground, and adjust the working pressure of the drip irrigation head to close to the minimum working pressure P 工 Specifically, by changing the number of turns of the pressure regulating screw c min Adjust to the minimum working pressure P with different groove widths工 ;

[0072] S5. Adjust the same distance L i Other drip irrigation heads at working pressure P 工

[0073] For the same maximum distance L max For other drip irrigation heads, select spiral sleeves with the same number of turns and different spiral groove widths to adjust the working pressure of other drip irrigation heads to the minimum working pressure P 工 ;

[0074] S6.L i =L i -Gap, Gap is the interval (unit: m); if L i >2m, go to step S4; if L i ≤2m, go to step S7;

[0075] S7. End the voltage regulation work.

[0076] Example 2

[0077] Concept: Additional flow channel + return flow channel + pressure regulating flow channel, through ① the pressure regulating flow channel length and screw groove width to cope with the change of water inlet pressure. Other structures are the same as embodiment 1.

[0078] like Figure 6 、 7 As shown, a pressure-compensated underground drip irrigation head includes

[0079] The second body 12 or the water inlet portion 40 is provided with an internal screw assembly 80, which includes internal screw ridges 82 provided on the inner wall of the second body 12, and internal spiral grooves 83 are formed between the internal screw ridges 82; the outer wall of the first body 11 is provided with a connecting channel 38 along the axial direction;

[0080] The open ends of the first body 11 and the second body 12 are inserted into the second body 12 facing each other until they abut and seal to form a drip irrigation chamber 13, so that a spiral additional flow channel 81 is formed between the first body 11 and the second body 12. At the same time, the connecting channel 38 connects the additional flow channel 81 with the return flow channel 21 located in the first body 11, and a second pressure reduction channel 17 is formed in the drip irrigation chamber 13 at the same axial position as the additional flow channel 81 in the radial direction embedded in the return flow channel 21.

[0081] The second body 12 includes a stepped cylinder 39, in which a spiral assembly 30 is disposed, forming a spiral pressure regulating channel 31 between the inner wall of the stepped cylinder 39 and the spiral assembly 30. The pressure regulating channel 31 is connected in series between the return channel 21 and the water outlet 50.

[0082] The first body 11 includes a closed, integrally formed cylindrical bottom wall at its head end and an open end at its tail end. The second body 12 has a water outlet 50 at its tail end and an open end at its head end. The open ends are both oriented outward along the axis. The open ends of the first and second bodies 11, 12 are inserted into the second body 12 facing each other. "Facing each other" means that the axes of the open ends coincide and are in opposite directions. The open ends of the first and second bodies 11, 12 are inserted into the second body 12 in the same direction. "In the same direction" means that the axes of the open ends coincide and are in the same direction.

[0083] like Figure 7 As shown, the open end of the second body 12 is sealedly engaged with the water inlet portion 40. The water inlet portion 40 includes an annular cover plate 41 and an open sleeve 43. The annular cover plate 41 is provided with multiple support protrusions 42. The support protrusions 42 support the bottom wall of the first body 11. The inner wall of the open sleeve 43 is provided with an internal screw assembly 80. The open end of the first body 11 is inserted into the open sleeve 43 in the same direction. The open sleeve 43 and the open end of the second body 12 are sealed in facing each other. At the same time, the open end of the first body 11 abuts the second body to form the drip irrigation chamber 13, so that a spiral additional flow channel 81 is formed between the first body 11 and the open sleeve 43. At the same time, the connecting channel 38 connects the additional flow channel 81 with the return flow channel 21 located in the first body 11. A second pressure reduction channel 17 is formed in the drip irrigation chamber 13, radially embedded in the return flow channel 21 at the same axial position as the additional flow channel 81.

[0084] The advantage of this embodiment is that the additional flow channel 81 is added without increasing the length, so that the drip irrigation head is suitable for higher water pressure and the drip irrigation amount of the drip irrigation head is more easily controlled.

[0085] Example 3

[0086] Concept: Add a secondary return channel 27 to each return branch channel 26 of the return channel 21, and adjust the flow channel length and screw groove width to cope with the change of water inlet pressure. Other structures are the same as those in embodiment 1 or 2.

[0087] like Figure 8 、 9 As shown, a pressure-compensated underground drip irrigation head includes

[0088] The flow ring plate 22 includes a plurality of first spacer columns 25.1 and a second spacer column 25.2 spaced apart on the closed-loop belt body 24 opposite the side concave cavity 14.2, and a plurality of support ribs 28 arranged in parallel and at intervals between the first spacer columns and the second spacer columns. The support ribs 28 alternately abut against the first cavity 14, so that a secondary return channel 27 is formed in the return diversion channel 26.

[0089] The main water flow enters the drip irrigation head from the water inlet 40 and enters the return channel 21. When the water flows into each return branch channel 26, it must flow through the secondary return channel 27 provided therein before entering the next return branch channel 26. The number of returns of the water flow increases exponentially, and the pressure drop is further reduced.

[0090] Example 4

[0091] Concept: A one-way membrane valve is added to the inlet so that when the water pressure is stopped, backflow will not clog the drip irrigation nozzle. The other structures are the same as those in embodiments 1, 2, and 3.

[0092] like Figure 10 、 11 As shown, a pressure-compensated underground drip irrigation head includes

[0093] The water inlet 40 is equipped with an anti-backflow mechanism 70. When the main line water pressure drops, the anti-backflow mechanism 70 is used to prevent liquid in the drip irrigation chamber from flowing back into the main line. The anti-backflow mechanism 70 includes a plug 71, a U-shaped elastic arm 72, and a fixed arm 73, which are integrally connected in sequence. The water inlet 40 is provided with a plug recess 74. When the main line water pressure is greater than or equal to the water pressure in the drip irrigation chamber 13, the plug 71 pops open and water is admitted. When the main line water pressure is less than or equal to the drip irrigation chamber water pressure, the plug 71 fits into the plug recess 74, and the water pressure in the drip irrigation chamber acts on the plug 71, preventing it from flowing back into the main line. Because the water pressure in the drip irrigation chamber 13 does not drop suddenly, the water outlet of the water outlet 50 will not draw in mud and block the pressure regulating channel. In addition, the pressure regulating channel 31 is located at the maximum radius position of the second main body 12 or the stepped cylinder 39. Even if the water outlet located at the axis sucks in mud, it is difficult for the mud to continue to enter and fall at the spiral outlet of the spiral pressure regulating channel. Therefore, the anti-clogging function is excellent.

[0094] The drip irrigation head also includes a deformable portion 75, which is disposed between the U-shaped elastic arm 72 and the fixed arm 73. The deformable portion 75 is formed between the U-shaped elastic arm 72 and the fixed arm 73 by installing an anti-deformation metal rod core 76 within the U-shaped elastic arm 72 and fixing the fixed arm 73 to the inner wall of the drip irrigation head. When the drip irrigation chamber 13 is under positive pressure, the plug 71 and the U-shaped elastic arm 72 rotate outward about the deformable portion 75 and deform, allowing water to enter through the water inlet 40. When the drip irrigation chamber 13 is under negative pressure, the plug 71 and the U-shaped elastic arm 72 rotate inward about the deformable portion 75 and deform, allowing water to enter through the water inlet 40.

[0095] The anti-backflow mechanism 70 has excellent water permeability under normal water pressure of 60-130 kPa, and has high non-return reliability under lower water pressure. Although the anti-backflow mechanism 70 can prevent backflow, it is not recommended to remove the filter 51 of the water outlet 50.

[0096] Principle description:

[0097] (1) The folding assembly 20 cooperates with the pressure regulating assembly 30 to realize the connection between the folding channel 21 and the pressure regulating channel 31 in series.

[0098] The return flow channel + pressure regulating flow channel has limited pressure reduction, and the pressure regulating flow channel 31 must be connected in series to further reduce the pressure, so that the drip irrigation head can achieve a drip irrigation rate of 2-6L / h under a suitable working pressure range.

[0099] Additional flow channel 81 + return flow channel + pressure regulating flow channel, the return flow channel 21 is radially embedded in the additional flow channel 37 to further reduce the pressure to meet the required drip irrigation rate under higher working pressure.

[0100] (Return channel + secondary return channel) + pressure regulating channel, or additional channel 81 + (return channel + secondary return channel) + pressure regulating channel, the return branch channel of the return channel 21 is embedded in the secondary return channel 27 to further reduce the pressure to meet the required drip irrigation rate under higher working pressure.

[0101] The combination of the above-mentioned different flow channels makes it possible for the drip irrigation head to cope with higher working pressure.

[0102] (2) The pressure adjustment by the number of turns and the pressure adjustment by the width of the spiral groove make the pressure adjustment more precise and the equal pressure adjustment is simple and easy.

[0103] Drip heads at different radii or distances from the water tank can be adjusted using different numbers of turns. Other drip heads at the same radius can be adjusted using different spiral groove widths using the same number of turns. The spiral sleeve 33 has a loop series Q1 with the same groove width but no turns, and a groove series Q2 with the same number of turns but different groove widths. Different radii or distances can be found in loop series Q1, while those with the same radius or distance can be found in groove series Q2. Select the appropriate spiral sleeve 33 from Q1 or Q2, install it into the drip head, and the pressure adjustment for that drip head is complete, making adjustment more refined and easier.

[0104] The pressure adjustment scale is accurate to 0.1m head pressure, making installation and commissioning easy to operate. After testing and commissioning, all drip irrigation heads can provide about 10% flow uniformity at the appropriate input pressure.

[0105] (3) By providing the anti-return mechanism 70, clogging prevention can be easily achieved.

[0106] The anti-backflow mechanism 70 blocks the water inlet with a plug when the main water pressure is released, so that liquid can only flow in the forward direction in the drip irrigation chamber but not in the reverse direction, thereby achieving a highly reliable and excellent anti-backflow effect and preventing the drip irrigation head from being blocked.

[0107] The pressure-compensated underground drip irrigation head and the control method for high uniformity of drip irrigation pressure of the present application achieve the increase of flow channel without increasing the external length of the drip irrigation head through different combinations of return components and spiral components. At the same time, the pressure uniformity is adjusted by a series of spiral components with the number of spiral turns and the width of the spiral groove, which is easy and fast to adjust into place, providing simple and feasible guarantees for the installation and commissioning of a large number of drip irrigation heads, and has great value for promotion and application.

Claims

1. A pressure-compensated underground drip irrigation head, characterized in that: include The main body (10) comprises a first main body (11) and a second main body (12), wherein the first main body (11) is provided with a first cavity (14), and the second main body (12) is provided with a second cavity (15); A foldback assembly (20) is disposed in the first cavity (14) of the first body (11), the foldback assembly (20) comprising a plurality of alternately stacked flow ring plates (22) and baffle plates (23), such that a foldback flow channel (21) is formed between the foldback assembly (20) and the first body (11); A spiral assembly (30) is disposed in the second cavity (15) of the second body (12), the spiral assembly (30) comprising a spiral groove (32), and a pressure regulating channel (31) is formed between the spiral groove (32) and the second body (12); When the second body (12) is sealed and joined to the first body (11), the first cavity (14) is connected to the second cavity (15) to form a drip irrigation cavity (13), and the return flow channel (21) is connected in series to the pressure regulating flow channel (31).

2. The pressure-compensated underground drip irrigation head according to claim 1, characterized in that: The first body (11) has a water inlet portion (40) at its head end and an open end at its tail end; the second body (12) has a water outlet portion (50) at its tail end and an open end at its head end; the first body and the second body are coaxial and the open ends are sealed and joined facing each other to form the drip irrigation chamber (13), and a return flow channel is formed in the drip irrigation chamber (13) in series with a pressure regulating flow channel and a first pressure reducing channel (16) arranged successively along the axial direction.

3. The pressure-compensated underground drip irrigation head according to claim 1, characterized in that: The second body (12) further includes an inner screw assembly (80), the inner screw assembly (80) including inner screw ridges (82) provided on the inner wall of the second body (12), and inner spiral grooves (83) formed between the inner screw ridges (82); a connecting channel (38) is provided on the outer wall of the first body (11) along the axial direction; the open ends of the first body (11) and the second body (12) are inserted into the second body (12) in opposite directions until they abut against the second body or the first body (11) and the open end of the water inlet portion (40) are inserted in the same direction The water inlet portion (40) is connected to the second main body and sealed to form the drip irrigation chamber (13), so that a spiral additional flow channel (81) is formed between the first main body (11) and the second main body (12). At the same time, the connecting hole (38) connects the additional flow channel (81) with the return flow channel (21) located in the first main body (11), and a second pressure reduction channel (17) is formed in the drip irrigation chamber (13) at the same axial position as the additional flow channel (81) in the radial direction and embedded in the return flow channel (21).

4. The pressure-compensated underground drip irrigation head according to any one of claims 1 to 3, characterized in that: The first cavity (14) includes a base cavity (14.1) and side concave cavities (14.2) symmetrically arranged on both sides of the base cavity and connected thereto; N flow-through annular plates (22) are stacked with N baffle plates (23), and the baffle plates (23) alternately abut the side concave cavities (14.2) on both sides to form N-1 return flow channels (26) that are connected end to end and have opposite flow directions and are connected end to end; an N+1th flow-through annular plate (22) is provided on the back of the Nth baffle plate (23) for abutting the second body (12); an Nth return flow channel (26) is formed between the N+1th flow-through annular plate (22) and the second body (12).

5. The pressure-compensated underground drip irrigation head according to claim 4, characterized in that: The flow ring plate (22) comprises a plurality of first spacer columns (25.1) and second spacer columns (25.2) arranged on the closed-loop belt body (24) at intervals opposite to the side concave cavity (14.2), and a plurality of support ribs (28) arranged in parallel and at intervals between the first spacer columns and the second spacer columns. The support ribs (28) alternately abut against the base cavity (14.1), so that a secondary return channel (27) is formed in the return branch channel (26).

6. The pressure-compensated underground drip irrigation head according to claim 1, characterized in that: The spiral assembly (30) includes a sleeve body (33), the sleeve body (33) is provided with external spiral ridges (36), and spiral grooves (32) are formed between the external spiral ridges (36). The sleeve body (33) is inserted into the second body (12). When the sleeve body and the inner wall of the second body form a spiral pressure regulating flow channel (31), the pressure ring sleeve (35) is threadedly engaged with the second body (12) to coaxially press the sleeve body (33) therein.

7. The pressure-compensated underground drip irrigation head according to claim 6, characterized in that: The invention comprises a series of sleeve bodies (33), wherein the series comprises a series of circles (Q1) with the same groove width but different numbers of circles and a series of grooves (Q2) with the same number of circles but different groove widths.

8. The pressure-compensated underground drip irrigation head according to claim 7, characterized in that: The invention also includes an anti-return mechanism (70) provided at the water inlet portion (40), the anti-return mechanism (70) including a plug (71), a U-shaped elastic arm (72) and a fixed arm (73) connected in sequence as a whole, the water inlet portion (40) is provided with a plug pit (74), the plug (71) is fitted in the plug pit (74), and the fixed arm (73) is fixedly provided beside the water inlet portion (40).

9. The pressure-compensated underground drip irrigation head according to claim 5, characterized in that: The second body (12) includes a stepped cylinder (39), and a spiral assembly (30) is provided in the stepped cylinder (39), so that the pressure regulating channel (31) is formed between the inner wall of the stepped cylinder (39) and the spiral assembly (30).

10. A method for controlling high uniformity of drip irrigation pressure of a pressure-compensated underground drip irrigation head according to any one of claims 1 to 9, characterized in that: S1. Arrange drip irrigation pipes and build up the water head pressure of the drip irrigation pipes; S2. Determine the minimum working pressure P at the farthest distance and the highest position on the ground 工 ; S3. Adjust the maximum distance L max The pressure of the drip irrigation cavity of other drip irrigation heads is adjusted to the minimum working pressure P 工 ;L i =L max -Gap, Gap is the arrangement radius interval of the drip irrigation head; S4. At the longest distance L i , find the drip irrigation head at the highest position on the ground, and adjust the pressure of the drip irrigation chamber of the drip irrigation head to close to the minimum working pressure P 工 ; S5. Adjust the same distance L i Other drip irrigation heads at working pressure P 工 ; S6.L i =L i -Gap; if L i >2m, go to step S4; if L i ≤2m, go to step S7; S7. End the voltage regulation work.

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