A U-shaped counter-flow channel and an irrigator based on the channel

Abstract

The present invention provides a U-shaped counter-flow channel and an irrigator based on the flow channel, wherein the counter-flow channel comprises: a flow channel cavity having a plurality of channels connected in series in sequence, the outlet end of the flow channel cavity having a transition channel extending outward, the width of the transition channel being smaller than the width of the flow channel cavity; a water diversion piece located in the flow channel cavity, the flow channel cavity being divided into two water flow channels spaced apart on the left and right, the two water flow channels being connected on the back water surface of the water diversion piece; wherein the water flow channel has a gradually expanding section extending to the outlet of the flow channel cavity. The left and right water flow channels of the present invention circulate simultaneously, doubling the anti-blocking performance of the flow channel cavity; the two water flow channels are counter-mixed on the back water surface of the water diversion piece, achieving an efficient energy dissipation effect, which is beneficial to reducing the flow state index of the irrigator and making the dripping more uniform; due to the setting of the gradually expanding section, the cross-sectional area of ​​the water flow channel increases along the direction of the water flow, increasing the head loss and achieving the effect of regulating pressure and stabilizing flow.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural water-saving irrigation, and in particular to a U-shaped counter-flow channel and an irrigator based on the flow channel. Background Art

[0002] Drip irrigation is one of the internationally recognized technologies with high water-saving effects, and is also the most effective water-saving irrigation method in arid and water-scarce areas. As one of the most critical components of the drip irrigation system, the structure and hydraulic performance of the emitter affect its anti-clogging performance and irrigation uniformity.

[0003] The purpose of the emitter is to adjust the pressure and stabilize the flow rate by changing the flow channel structure and form. Currently, the commonly used emitters are mainly divided into turbulent maze type and pressure compensation type. The former has a relatively simple energy dissipation method and a flow index between 0.5 and 0.65. The latter has a flow index less than 0.2, but a more complex structure, and the internal elastic diaphragm is easily deformed, resulting in poor pressure regulation and flow stabilization performance, and the diaphragm deformation is difficult to accurately control. The above two types of emitters are prone to clogging, short life, and uneven water output due to insufficient energy dissipation. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art sprinkler that it is easy to be blocked and has insufficient energy dissipation, thereby providing a U-shaped counter-flow channel and a sprinkler based on the channel.

[0005] In order to solve the above technical problems, the present invention provides a U-shaped counter-flow channel, comprising:

[0006] A flow channel cavity, comprising a plurality of flow channel cavities connected in series, wherein an outlet end of the flow channel cavity has a transition channel extending outward, and a width of the transition channel is smaller than a width of the flow channel cavity;

[0007] A water dividing member is located in the flow channel cavity, the flow channel cavity is divided into two water flow channels spaced apart from each other, and the two water flow channels are connected at the back surface of the water dividing member;

[0008] Wherein, the water flow channel has a gradually expanding section extending to the outlet of the flow channel cavity.

[0009] Furthermore, the outlet of the flow channel cavity has pointed teeth portions which are arranged opposite to each other, and the pointed corners of the pointed teeth portions face the back water surface of the water dividing element.

[0010] Furthermore, the water flow channel has a guide portion extending toward the outlet of the flow channel cavity, and the guide portion is spaced apart from and opposite to the back water surface of the water diversion member.

[0011] Furthermore, the guide portion is an arc surface, and the center of curvature of the arc surface is located in the flow channel cavity.

[0012] Furthermore, the outlet and inlet of the flow channel cavity are coaxially arranged, and the water distribution components are distributed along the axis of the inlet / outlet.

[0013] Furthermore, the water diversion element is a D-shaped structure, having a straight water-facing surface and an arc-shaped water-receiving surface.

[0014] Furthermore, the width of the water flow channel is not less than the width of the flow channel cavity.

[0015] A water emitter has the U-shaped counter-flow channel described in any one of the above schemes.

[0016] The technical solution of the present invention has the following advantages:

[0017] 1. The U-shaped counter-flow channel provided by the present invention has a flow channel cavity divided into two left and right water flow channels by a water divider, which doubles the anti-clogging performance of the flow channel cavity; the two water flow channels are counter-mixed on the back water surface of the water divider to achieve a highly efficient energy dissipation effect, which is beneficial to reduce the flow state index of the sprinkler and make the dripping more uniform; the setting of the gradual expansion section increases the cross-sectional area of ​​the water flow channel along the direction of the water flow, increases the head loss, and achieves the effect of pressure regulation and flow stabilization. The above-mentioned U-shaped counter-flow channel can achieve the effects of energy dissipation, pressure regulation, flow stabilization and anti-clogging, thereby making the drip irrigation more uniform.

[0018] 2. The U-shaped counter-flow channel provided by the present invention has sharp teeth at the outlet of the channel cavity that can adjust the directions of the left and right water flows, so that the two water flows can form a 180° counter-flow energy dissipation as much as possible, thereby improving the energy dissipation effect; and a protruding contraction structure is formed at the sharp teeth to further increase the head loss.

[0019] 3. The U-shaped counter-flow channel provided by the present invention has a guide portion which is an arc surface. The arc surface replaces the bending structure, thereby increasing the internal space of the flow channel, reducing the migration resistance of solid particles near the wall, and further increasing the anti-blocking ability of the flow channel cavity.

[0020] 4. The U-shaped counter-flow channel provided by the present invention has a D-shaped water diversion piece, and the straight water-facing surface vertically counter-flows the inlet water flow to increase the energy dissipation effect; the arc-shaped back-water surface causes the water flow to perform centrifugal motion, so that the solid particles return to the mainstream area and are not conducive to adhering to the back-water surface of the water diversion piece, further increasing the anti-blocking ability of the flow channel cavity.

[0021] 5. The U-shaped counter-flow channel provided by the present invention has a water flow channel whose width is not less than the width of the flow channel cavity, thereby improving the drip irrigation speed while ensuring uniform drip irrigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the structure of the sprinkler provided in the present invention.

[0024] Figure 2 Schematic diagram of the structure of the counter flow channel.

[0025] Figure 3 Schematic diagram of the dimensions of the counter flow channel.

[0026] Figure 4 It is the pressure-flow relationship curve of the counter flow channel.

[0027] Figure 5 It is the velocity cloud diagram of the counter flow channel.

[0028] Figure 6 Streamline diagram of the flow channel cavity.

[0029] Description of reference numerals:

[0030] 1. Water inlet; 2. Water outlet; 3. U-shaped channel; 4. Flow channel cavity; 5. Transition channel; 6. Water distribution piece; 7. Guide part; 8. Sharp tooth part. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] This embodiment provides a specific implementation of an emitter, such as Figure 1 As shown, the sprinkler includes: a water inlet 1, a water outlet 2, a U-shaped counter-flow channel, and a U-shaped channel 3; the counter-flow channel is connected between the water inlet 1 and the water outlet 2, and the U-shaped channel 3 is used to connect two counter-flow channels spaced apart on the left and right.

[0036] like Figure 1 , Figure 2 As shown, the U-shaped counter-flow channel includes a plurality of flow channel cavities 4 connected in series in sequence, wherein the flow channel cavity 4 is a rectangular structure having a cavity that passes through from front to back; the cross-sectional dimensions of the inlet / outlet of the flow channel cavity 4 are consistent, and the inlet / outlet are coaxially arranged; the outlet end of the flow channel cavity 4 has a transition channel 5 extending outward, the width of the transition channel 5 is smaller than the width of the flow channel cavity 4, and the transition channel 5 is used to connect two adjacent flow channel cavities 4.

[0037] like Figure 2 As shown, the flow channel cavity 4 is formed by additive manufacturing; there is a water dividing member 6 in the flow channel cavity 4, and the water dividing member 6 is arranged along the inlet / outlet axis of the flow channel cavity 4; the water dividing member 6 divides the flow channel cavity 4 into two left and right water flow channels, so that the anti-clogging performance of the flow channel cavity 4 is doubled.

[0038] like Figure 2 As shown, the water divider 6 is a D-shaped structure, having a straight water-facing surface and an arc-shaped water-receiving surface; the water-facing surface of the water divider 6 is spaced opposite to the inlet end of the flow channel cavity 4 and covers the inlet of the flow channel cavity 4; the inlet water flow and the water-facing surface of the water divider 6 are vertically impacted, which has the effect of energy dissipation; the water-receiving surface of the water divider 6 is spaced opposite to the outlet end of the flow channel cavity 4 and covers the outlet of the flow channel cavity 4; the arc-shaped water-receiving surface causes the water flow to perform centrifugal motion, so that the solid particles return to the mainstream area and are not conducive to adhering to the water-receiving surface of the water divider 6, further increasing the anti-blocking ability of the flow channel cavity 4.

[0039] like Figure 2As shown, two water flow channels spaced apart on the left and right merge at the back surface of the water divider 6, and the two water flows counteract each other to dissipate energy. The water flow channel has a guide portion 7 extending toward the outlet of the flow channel cavity 4, and the guide portion 7 is a circular arc surface spaced opposite to the back surface of the water divider 6, and the center of curvature of the circular arc surface is located in the flow channel cavity 4; the guide portion 7 replaces the bending structure, increases the internal space of the flow channel; and can reduce the migration resistance of solid particles near the guide portion 7, further increasing the anti-blocking ability of the flow channel cavity 4.

[0040] like Figure 2 As shown, the outlet of the flow channel cavity 4 has sharp teeth 8 arranged opposite to each other on the left and right, and the sharp corners of the sharp teeth 8 face the back water surface of the water diversion member 6; the sharp teeth 8 can adjust the flow direction of the water flow so that the two left and right water flows can achieve 180° counter-impact energy dissipation as much as possible; and a protruding contraction structure is formed at the sharp teeth to further increase the head loss.

[0041] like Figure 3 As shown, the width of the flow channel cavity 4 is d1, and the value range of d1 is 2.6±0.2mm; the length of the flow channel cavity 4 is d2, and the value range of d2 is 2.9±0.2mm; the vertical distance between the inlet end of the flow channel cavity 4 and the water-facing surface of the water distribution member 6 is d3, and the value range of d2 is 0.8±0.2mm; the width of the transition channel 5 is d4, and the value range of d4 is 0.8±0.2mm; the radius of the water distribution member 6 is R, and the value range of R is 0.7±0.2mm.

[0042] Fluent numerical simulation was performed on the U-shaped counter-flow channel. The inlet pressure range was 0.05-0.25 MPa, and the gradient was 0.01 MPa. Numerical simulation was performed to obtain the flow values ​​under different pressures. Then, linear fitting was performed to obtain a flow index of 0.4755. The pressure-flow curve is shown in Figure 4 shown.

[0043] like Figure 5 As shown in FIG. 1 , it is a velocity cloud diagram of the U-shaped counter-flow channel; it can be seen from the velocity cloud diagram that the water flow in the channel is continuous and uniform, and there are few velocity dead zones; although a certain area of ​​velocity dead zones is formed on the back surface of the water divider 6, the sediment particles are purposefully adhered to the back surface of the water divider 6 with a large space to improve the anti-blocking performance, in addition, the existence of water flow forms such as folding and vortex in the entire flow channel is beneficial to energy dissipation. The velocity is extremely high at the transition channel 5, which is conducive to the water flow carrying sediment particles out.

[0044] like Figure 6As shown, it is a streamline diagram of the U-shaped counter-flow channel; it can be seen from the streamline diagram that there are no small vortices in the single flow channel cavity 4, and there are two large vortices driven by the mainstream area, which are helpful to the energy dissipation of the flow channel. The water flows in the left and right water flow channels are strongly counter-mixed in the sharp tooth part 8, which greatly consumes the kinetic energy of the water flow.

[0045] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A U-shaped counter-flow channel, characterized in that: include: A flow channel cavity (4) having a plurality of channels connected in series, wherein the outlet end of the flow channel cavity (4) has a transition channel (5) extending outward, and the width of the transition channel (5) is smaller than the width of the flow channel cavity (4); A water dividing member (6) is located in the flow channel cavity (4), the flow channel cavity (4) is divided into two water flow channels spaced apart from each other on the left and right, the two water flow channels are connected at the back surface of the water dividing member (6), the water dividing member (6) is a D-shaped structure, having a straight water-facing surface and a curved back surface; The water flow channel comprises a gradually expanding section extending to the outlet of the flow channel cavity (4) and a flow guide portion (7) extending towards the outlet of the flow channel cavity (4); the outlet of the flow channel cavity (4) comprises a pointed tooth portion (8) arranged opposite to each other, the pointed corner of the pointed tooth portion (8) faces the back water surface of the water diversion element (6); the flow guide portion (7) is spaced opposite to the back water surface of the water diversion element (6); The flow guide portion (7) is a circular arc surface, and the center of curvature of the circular arc surface is located in the flow channel cavity (4).

2. The U-shaped counter-flow channel according to claim 1, characterized in that: The outlet and the inlet of the flow channel cavity (4) are coaxially arranged, and the water distribution element (6) is distributed along the axis of the inlet / outlet.

3. The U-shaped counter-flow channel according to claim 1, characterized in that: The width of the water flow channel is not less than the width of the flow channel cavity (4).

4. A water emitter, characterized in that: The invention has a U-shaped counter-flow channel as described in any one of claims 1 to 3.

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