An ultrasonic flow measuring instrument applied to small irrigation channels

Abstract

The utility model discloses a kind of ultrasonic flow measuring instruments applied to small irrigation channel, including the uniform distribution of multiple pairs of ultrasonic transducer along the center axis direction of irrigation channel;Two ultrasonic transducers in the same pair are respectively fixed on the two sides of the outer surface of irrigation channel to form a pair of emission structure, and the formed acoustic channel passes through the center axis of irrigation channel;Each ultrasonic transducer is fixed on the outer surface of irrigation channel by respective mounting plate;The mounting plate is inverted U type.The ultrasonic flow measuring instrument of the utility model can be under the condition of low water head, high silt accumulation, multiple frost heaving, large flow variation Let the flow measurement accuracy be superior to ±5%.

Description

Technical Field

[0001] This utility model relates to the field of ultrasonic flow measurement instrument technology, specifically to an ultrasonic flow measurement instrument applied to small irrigation channels. Background Technology

[0002] Existing ultrasonic flow measurement instruments for channels mainly include weir-type, flume-type, ultrasonic, electromagnetic, and radar types. Weir-type (such as triangular weirs and rectangular weirs) and flume-type (such as Parshall flumes) are the most traditional types, developed based on the steady flow energy equation for open channels. They have been widely used in irrigation and water supply and drainage projects since the 19th century, calculating flow rate through the water level-flow relationship of a fixed weir / flume. While technically mature, they rely on fixed hydraulic structures. Ultrasonic flow meters emerged with the advancements in acoustic technology in the 20th century. They are divided into contact (underwater transducer) and non-contact (measuring velocity above the water surface) types, calculating velocity based on the Doppler effect or time-of-flight method of sound wave propagation in fluids, and are suitable for complex cross-sections. Electromagnetic flow meters are based on Faraday's law of electromagnetic induction and were applied to open channels in the mid-to-late 20th century. They require conductive fluid and are not designed for full-pipe operation, relying on velocity-cross-sectional area conversion. Radar flow meters are a product of recent miniaturization of radar technology, measuring surface velocity non-contactly and suitable for harsh environments, requiring no contact with the water body.

[0003] Conventional irrigation canal measuring instruments have significant limitations under complex working conditions. They are inaccurate at low water heads. Most instruments (such as Parshall flume and thin-walled weir) rely on a certain water head difference to achieve measurement. However, a gentle slope will lead to low water velocity and insufficient water head, which will easily result in uneven velocity distribution and cause the measured value to deviate from the actual flow rate. The error is particularly significant at low flow rates.

[0004] In addition, existing conventional irrigation canal measuring instruments have weak resistance to frost heave and deformation. Therefore, relying on fixed concrete bases for installation can lead to base cracking, instrument displacement, damage to the original hydraulic structure (such as weir dimensions and sensor positions), resulting in long-term decrease in measurement accuracy and even equipment damage.

[0005] Furthermore, existing conventional irrigation canal measuring instruments are not resistant to siltation and sedimentation, which can easily clog critical parts of the instruments (such as the electrodes of electromagnetic flowmeters and ultrasonic transducers). When sedimentation varies greatly, instruments with a fixed cross-section design cannot match the actual cross-section, resulting in significant deviations between the measured values ​​and the actual flow rate, and requiring frequent dredging and maintenance.

[0006] Furthermore, conventional irrigation canal measuring instruments are difficult to adapt to flow fluctuations: conventional instruments have a narrow range, weak signal and low accuracy at low flow rates, and are prone to exceeding the range at high flow rates; at the same time, the response speed is slow, making it difficult to capture instantaneous flow changes, and cannot meet the dynamic measurement needs of irrigation conditions such as watering and water stoppage. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model aims to provide an ultrasonic flow measuring instrument for use in small irrigation channels, enabling flow measurement under conditions of low water head, high siltation, frequent frost heave, and large flow variations.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An ultrasonic flow measuring instrument for small irrigation channels includes multiple pairs of ultrasonic transducers evenly distributed along the central axis of the irrigation channel; two ultrasonic transducers in the same pair are respectively fixed on both sides of the outer surface of the irrigation channel to form a through-beam structure, and the formed sound channel passes through the central axis of the irrigation channel; each ultrasonic transducer is fixed to the outer surface of the irrigation channel by its own mounting plate; the mounting plate is inverted U-shaped.

[0010] Furthermore, the outer surface of the irrigation channel is provided with an installation groove, and the installation plate is fixed in the installation groove by stainless steel expansion bolts. The gap between the installation groove and the installation plate is filled with gravel or aeolian sand.

[0011] Furthermore, the ultrasonic transducer is embedded inside the ball joint structure, which is rotatably embedded in the receiving cavity at the top of the base, and the bottom plate of the base is fixed to the mounting plate by screws.

[0012] Furthermore, a rubber ring is provided between the base and the mounting plate.

[0013] Furthermore, the ball joint structure is made of stainless steel.

[0014] The beneficial effects of this utility model are as follows:

[0015] 1. This utility model uses multiple pairs of transducers in combination to form multiple channels and obtain multi-layer velocity distribution information of the irrigation channel flow field.

[0016] 2. The ultrasonic transducer of this utility model is pre-installed on the surface of the irrigation channel using an inverted U-shaped mounting plate, which can effectively prevent frost heave and facilitate overall disassembly and maintenance.

[0017] 3. In this utility model, embedding the ultrasonic transducer into the ball joint structure can solve the problems of flow obstruction and grass snagging.

[0018] In summary, the ultrasonic flow measuring instrument of this invention can achieve a flow measurement accuracy of better than ±5% under conditions of low head, high siltation, frequent frost heave, and large flow variation. Attached Figure Description

[0019] Figure 1 This is an example diagram showing the distribution of ultrasonic transducers on irrigation channels in this utility model embodiment;

[0020] Figure 2 This is a schematic diagram of the installation of the ultrasonic transducer on the surface of the irrigation channel in an embodiment of this utility model;

[0021] Figure 3 This is a schematic diagram of the ultrasonic transducer being fixed in an embodiment of this utility model. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to this embodiment.

[0023] This embodiment provides an ultrasonic flow measuring instrument for use in small irrigation channels, such as... Figure 1-3 As shown, it includes multiple pairs of ultrasonic transducers 1 evenly distributed along the central axis of the irrigation channel 100; two ultrasonic transducers 1 in the same pair are respectively fixed on both sides of the outer surface of the irrigation channel 100 to form a through-beam structure, and the formed sound channel passes through the central axis of the irrigation channel; each ultrasonic transducer 1 is fixed to the outer surface of the irrigation channel 100 by its own mounting plate 7; the mounting plate 7 is inverted U-shaped.

[0024] The inverted U-shaped mounting plate 7 provides a unified installation reference for the transducers, ensuring the integrity of transducers on the same side and reducing the impact of channel surface deformation such as ground settlement and frost heave on the geometric parameters of the ultrasonic flow measurement system. It also facilitates later inspection and maintenance. Furthermore, the inverted U-shaped mounting plate 7 provides space for the transducers to sink, reducing the influence of the flow measurement system on the flow field. The hollow space at the bottom of the inverted U-shaped mounting plate 7 also provides wiring space for the transducer cables, facilitating wiring and protecting the cables from exposure to sunlight and damage. In addition, the inverted U-shaped structure has good overall rigidity and is not easily deformed, ensuring the stability of the geometric parameters of the flow measurement system.

[0025] In this embodiment, the outer surface of the irrigation channel 100 is provided with an installation groove 6, and the installation plate 7 is fixed in the installation groove 6 by stainless steel expansion bolts. The gap between the installation groove 6 and the installation plate 7 is filled with well-graded gravel or aeolian sand, which can reduce the influence of the flow measurement system on the flow field and at the same time strengthen the fixing effect of the installation plate 7.

[0026] In this embodiment, as Figure 2 As shown, the ultrasonic transducer 1 is embedded inside the stainless steel ball joint structure 2, which is rotatably embedded in the receiving cavity at the top of the base 3. The bottom plate of the base 3 is fixed to the mounting plate 7 by screws 4.

[0027] In this embodiment, a rubber ring 8 is provided between the base 3 and the mounting plate 6.

[0028] In the aforementioned ultrasonic flow measurement instrument, multiple pairs of transducers are used in combination to form multiple channels, thereby obtaining multi-layer velocity distribution information of the irrigation channel flow field. By forming a velocity distribution model through multi-layer velocity, the measurement accuracy problem under conditions of large liquid level changes can be solved.

[0029] Furthermore, since the ultrasonic transducer is installed outdoors, there are many factors affecting its geometric parameters, such as large outdoor temperature differences, geological subsidence, and frost heave. To ensure the relative stability of the ultrasonic transducer's installation parameters, this embodiment uses an inverted U-shaped mounting plate for installation. Before installation, the silty clay on the surface of the irrigation channel is removed, and the inverted U-shaped mounting plate with the ultrasonic transducer fixed to it is pre-installed on the surface of the irrigation channel. The slight deformation of the inverted U-shaped mounting plate itself absorbs uneven frost heave displacement, which can effectively prevent frost heave and facilitate the overall disassembly and maintenance of the ultrasonic transducer. In addition, the ultrasonic transducer is embedded in the ball joint structure 2, forming a flow-free structure. The arc-shaped structure of the ball joint structure 2 can also effectively prevent grass from getting caught.

[0030] The aforementioned ultrasonic flow measuring instrument can achieve a flow measurement accuracy of better than ±5% under conditions of high siltation, frequent frost heave, and large flow variation.

[0031] For those skilled in the art, various corresponding changes and modifications can be made based on the above technical solutions and concepts, and all such changes and modifications should be included within the protection scope of the claims of this utility model.

Claims

1. An ultrasonic flow measuring instrument for use in small irrigation channels, characterized in that, It includes multiple pairs of ultrasonic transducers evenly distributed along the central axis of the irrigation channel; two ultrasonic transducers in the same pair are fixed on both sides of the outer surface of the irrigation channel to form a through-beam structure, and the sound channel formed passes through the central axis of the irrigation channel; each ultrasonic transducer is fixed to the outer surface of the irrigation channel by its own mounting plate; the mounting plate is in the shape of an inverted U.

2. The ultrasonic flow measuring instrument according to claim 1, characterized in that, The outer surface of the irrigation channel is provided with an installation groove, and the installation plate is fixed in the installation groove by stainless steel expansion bolts. The gap between the installation groove and the installation plate is filled with gravel or aeolian sand.

3. The ultrasonic flow measuring instrument according to claim 1, characterized in that, The ultrasonic transducer is embedded inside the ball joint structure, which is rotatably embedded in the receiving cavity at the top of the base, and the bottom plate of the base is fixed to the mounting plate by screws.

4. The ultrasonic flow measuring instrument according to claim 3, characterized in that, A rubber ring is provided between the base and the mounting plate.

5. The ultrasonic flow measuring instrument according to claim 3, characterized in that, The ball joint structure is made of stainless steel.

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