An open channel flow detection device based on ultrasonic wave

Abstract

The present invention relates to the field of flow detection technology, and specifically to an open channel flow detection device based on ultrasound. The detection device includes a Parshall trough, a mounting frame, an ultrasonic probe and a flow meter. A conveying frame is arranged above the Parshall trough, and a bracket is arranged above the conveying frame. The mounting frame is arranged on the bracket and is located above the contraction end of the Parshall trough. The ultrasonic probe is arranged on the mounting frame. Compared with the current detection equipment, the present invention is provided with a retractable and liftable cleaning mechanism, which is driven by the conveying mechanism to move in the Parshall trough. The cleaning mechanism can clean some heavy and sticky impurities without interfering with the detection device to detect the flow. At the same time, the cleaning mechanism in the present invention has a large cleaning area and will not have a cleaning dead corner. In addition, when not working, it will not cause any obstruction to the flow of the fluid.

Description

Technical Field

[0001] The invention relates to the technical field of flow detection, and in particular to an open channel flow detection device based on ultrasonic waves. Background Art

[0002] Open channel flow detection refers to the process of monitoring and measuring the flow of fluid in an open channel (i.e., an open channel). Since the fluid in the open channel sometimes contains certain corrosiveness or carries a large amount of impurities, it is difficult for general pipeline flow meters to accurately detect the flow of the open channel. In many scenarios, users currently choose non-contact ultrasonic open channel flow meters to detect the flow of fluid in the open channel.

[0003] Existing ultrasonic open channel flow detection equipment sometimes has a filter to ensure detection accuracy, such as the patent "CN221425729U A sewage flow monitoring device based on an open channel flow meter", but in the actual test process, the presence of the filter will increase the water flow resistance and change the water flow state, thereby affecting the measurement accuracy. At the same time, the staff has to clean the filter every once in a while, which increases the workload of the staff; finally, when the ultrasonic open channel flow detection equipment works for a long time, the channel may be eroded or precipitated and deformed, resulting in gaps in the parts that were originally in close contact with the ultrasonic open channel flow detection equipment. If no remedial measures are taken at this time, the staff may misjudge the actual water flow velocity in the channel, and the existing ultrasonic open channel flow detection equipment usually does not have remedial measures. Summary of the invention

[0004] The object of the present invention is to provide an open channel flow detection device based on ultrasound to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an open channel flow detection device based on ultrasound, the detection device includes a Parshall trough, a mounting frame, an ultrasonic probe and a flow meter, a conveying frame is arranged above the Parshall trough, a bracket is arranged above the conveying frame, the mounting frame is arranged on the bracket and is located above the contraction end of the Parshall trough, the ultrasonic probe is arranged on the mounting frame, the flow meter is arranged on the outside of the Parshall trough, and the ultrasonic probe is connected to the flow meter through a cable. When the present invention is working, the Parshall trough is installed in the ditch, and the propagation time of the ultrasonic signal emitted by the ultrasonic probe in the fluid is measured to obtain the average flow velocity of the fluid (the functions realized by the ultrasonic probe and the flow meter belong to the conventional technical means in this field, and the specific structure is not described). As described above, compared with the current detection equipment, the present invention is provided with a retractable and liftable cleaning mechanism, the cleaning mechanism is arranged at the contraction end of the Parshall trough, and a conveying mechanism is arranged inside the conveying frame, and the cleaning mechanism is driven by the conveying mechanism to move in the Parshall trough, and the side walls and the bottom of the Parshall trough are cleaned by the cleaning mechanism to prevent impurities such as mud and sand from accumulating in the Parshall trough, so as to change the cross-sectional area of ​​the Parshall trough. Compared with the current method of vibrating the bottom of the Parshall trough to let impurities flow away with the water flow, or setting a filter to intercept impurities in the water flow, the cleaning mechanism provided in the present invention can clean some heavy and sticky impurities without interfering with the detection flow of the detection equipment. At the same time, the cleaning mechanism in the present invention has a large cleaning area, and will not cause any obstruction to the flow of the fluid when not working.

[0006] Furthermore, the conveying mechanism includes a conveying chain belt, and the cleaning mechanism includes a driving seat, a first cleaning frame and a second cleaning frame. The conveying frames are provided with two groups, and the two groups of conveying frames are relatively arranged at the two ends above the Parshall trough. A group of conveying chains is arranged in each group of the conveying frames, and a group of driving motors is arranged below each group of the conveying frames, and each group of driving motors is connected to a group of conveying chains. The driving seats are provided with two groups, and the two groups of driving seats are respectively arranged at one end of the two groups of conveying chains close to each other. A group of first cleaning frames is arranged below each group of the driving seats, and the second cleaning frame is arranged between the two groups of first cleaning frames. During the working process of the present invention, the two groups of driving motors can be regularly turned on, and the two groups of first cleaning frames and the second cleaning frames are driven to move in the Parshall trough by the two groups of driving motors and the two groups of conveying frames. During the movement of the first cleaning frame and the second cleaning frame, the first cleaning frame and the second cleaning frame can clean up impurities such as mud, sand, leaves, etc. attached to the inner wall and bottom of the Parshall trough, thereby preventing the cross-section of the Parshall trough from being indirectly changed and avoiding the detection accuracy from being affected.

[0007] Furthermore, the second cleaning frame includes a first telescopic frame, a second telescopic frame and a third telescopic frame, the first telescopic frame is connected to one group of first cleaning frames, the second telescopic frame is connected to another group of first cleaning frames, guide rods are arranged inside the first telescopic frame and the second telescopic frame, the third telescopic frame is arranged between the first telescopic frame and the second telescopic frame, and both ends of the third telescopic frame are movably installed inside the first telescopic frame and the second telescopic frame through guide rods. When the second cleaning frame in the present invention moves in the Parshall trough, the distance between the first telescopic frame and the second telescopic frame will change, and the third telescopic frame will shrink into the first telescopic frame and the second telescopic frame. Through the above technical solution, it is ensured that when the second cleaning frame moves to the contraction end, throat end and diffusion end of the Parshall trough, the second cleaning frame is always in full contact with all areas of the bottom surface of the Parshall trough to avoid cleaning dead corners.

[0008] Furthermore, a groove is provided at the bottom of the contraction end of the Parshall trough, a lifting groove is provided inside each group of the driving seats, a second electromagnet is provided at the upper end of each group of the lifting grooves, the upper end of each group of the first cleaning racks is inserted into the lifting groove, the upper end of each group of the first cleaning racks is magnetic, and a cleaning roller is provided at one end of each group of the first cleaning racks close to the inner wall of the Parshall trough. The present invention controls the lifting and lowering of the first cleaning rack and the second cleaning rack by the second electromagnet. When the cleaning mechanism is not working, the second cleaning rack is located in the groove to avoid affecting the flow of liquid in the ditch. When the cleaning mechanism is required to work, the first cleaning rack and the second cleaning rack are controlled to rise by the second electromagnet. At this time, the second cleaning rack will extend out of the groove and contact with the bottom of the Parshall trough. When the second cleaning rack moves, the bottom of the Parshall trough can be cleaned by the second cleaning rack.

[0009] Furthermore, in the present invention, when the Parshall trough is installed in the ditch, a plurality of groups of humidity detectors (not shown in the figure) are arranged on the outer wall surface of the Parshall trough, and whether leakage occurs between the Parshall trough and the ditch wall surface can be detected by the humidity detectors. Protection components are arranged on the outer sides of the contraction end and the diffusion end of the Parshall trough, and the protection components are electrically connected to the plurality of groups of humidity detectors. When leakage occurs between the Parshall trough and the ditch wall surface is detected, the protection components will automatically open, and the leakage can be remedied by the protection components.

[0010] Furthermore, the protective assembly includes a fixed seat and a protective cover, the protective cover is arranged on a side of the fixed seat away from the Parshall slot, and a push rod, a telescopic slot, a compression plate, an air storage tank and a first electromagnet are arranged inside the fixed seat, the first electromagnet is arranged at one end of the air storage tank, the compression plate is arranged in the air storage tank and has magnetism at one end close to the first electromagnet, the telescopic slot is connected to the air storage tank, one end of the push rod is connected to the protective cover, and the other end of the push rod is located in the telescopic slot. In the present invention, the air storage tank is filled with compressed gas. When leakage occurs between the Parshall slot and the wall of the ditch, the first electromagnet will generate a set of magnetic fields that repel the compression plate. At this time, the compression plate will squeeze the compressed gas in the air storage tank into the telescopic slot, so that the push rod drives the protective cover to move toward the direction of the ditch wall, and the leakage is remedied by the protective cover to prevent the liquid in the ditch from flowing from the outside of the Parshall slot.

[0011] Furthermore, slide grooves are provided at both upper and lower ends of the fixing seat, induction springs are provided in the slide grooves, induction blocks are provided at both upper and lower ends of the interior of the protective cover, the induction blocks are located in the slide grooves, and a piezoelectric sheet is provided at one end of the induction block close to the induction spring. When the protective cover in the present invention moves toward the ditch wall, the induction block will move synchronously, and the piezoelectric sheet will generate a group of electrical signals at this time. The staff can obtain the size of the gap between the Parshall trough and the ditch wall by monitoring the numerical changes of the electrical signals, and then judge the urgency of maintenance.

[0012] Furthermore, an arc seat and a baffle are provided below the mounting frame, and two groups of the arc seats are provided, and the two groups of the arc seats are relatively arranged on the left and right sides of the lower end of the ultrasonic probe, and two groups of the baffles are provided, and the two groups of the baffles are relatively arranged on the front and rear sides of the two groups of arc seats, and a group of arc covers are provided in each group of the arc seats, and a group of air pumps are provided at the side ends of each group of the arc seats, and each group of the air pumps is connected to the upper and lower ends of the arc seat through the first air duct and the second air duct, and the arc cover is controlled to move in the arc seat by the air pump. During the working process of the present invention, liquid splashing and the like are often encountered, especially when working outdoors, the lens of the ultrasonic probe is easily contaminated. The present invention protects the ultrasonic probe by providing two groups of arc covers to avoid affecting the detection accuracy.

[0013] Furthermore, the present invention controls the movement of the arc hood by delivering gas to the arc seat through an air pump, that is, when the air pump delivers gas to the lower end of the arc seat, the arc hood will retract into the arc seat, and when the air pump delivers gas to the upper end of the arc seat, the arc hood will extend out of the arc seat. Through the above technical scheme, the present invention provides a group of cleaning cottons at one end where the two groups of arc seats are close to each other, and each group of the cleaning cottons is located below the arc hood. Every once in a while, the staff can turn on the air pump once, and at this time the arc hood will first retract into the arc seat, and then extend out of the arc seat. During the movement of the arc hood, the cleaning cotton can automatically clean the arc hood, thereby ensuring that the arc hood will never be contaminated by impurities such as droplets or dust.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: compared with the current detection equipment, the present invention is provided with a retractable and liftable cleaning mechanism, which is driven by a conveying mechanism to move the cleaning mechanism in the Parshall trough, and the side walls and the bottom of the Parshall trough are cleaned by the cleaning mechanism to prevent impurities such as mud and sand from accumulating in the Parshall trough, thereby changing the cross-sectional area of ​​the Parshall trough. Compared with the current method of vibrating the bottom of the Parshall trough to allow impurities to flow away with the water flow, or setting a filter to intercept impurities in the water flow, the cleaning mechanism provided in the present invention can clean some heavy and sticky impurities without interfering with the flow rate detected by the detection equipment. At the same time, the cleaning mechanism in the present invention has a larger cleaning area without any cleaning dead corners. In addition, when not working, Nor will it cause any obstruction to the flow of the fluid. The present invention is also provided with a protective component. When the humidity detector detects leakage between the Parshall trough and the ditch wall, the leakage can be remedied through the protective component. At the same time, the protective component will send out a group of electrical signals to facilitate the staff to obtain the size of the gap between the Parshall trough and the ditch wall, and then judge the urgency of maintenance. The present invention is also provided with an arc cover. The arc cover protects the ultrasonic probe to avoid affecting the detection accuracy. The movement of the arc cover in the arc seat is controlled by an air pump. During the movement of the arc cover, the arc cover can be automatically cleaned by cleaning cotton, thereby ensuring that the arc cover will not be contaminated by impurities such as droplets or dust. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 The present invention Figure 1 Schematic diagram of the structure of the middle A part;

[0018] Figure 3 It is a schematic diagram of the internal structure of the conveyor frame of the present invention;

[0019] Figure 4 The present invention Figure 3 Schematic diagram of the structure of the middle BB part;

[0020] Figure 5 The present invention Figure 4 Schematic diagram of the structure of the middle C part;

[0021] Figure 6 It is a schematic structural diagram of a second cleaning frame of the present invention;

[0022] Figure 7 It is a schematic diagram of the structure of the protection component of the present invention;

[0023] Figure 8 It is a schematic diagram of the protective cover structure of the present invention;

[0024] Fig. 9 It is a schematic diagram of the lower structure of the mounting frame of the present invention.

[0025] In the figure: 1. Parshall trough; 2. Mounting frame; 21. Air pump; 22. Arc seat; 23. Cleaning cotton; 24. Arc cover; 25. Baffle; 3. Ultrasonic probe; 4. Flow meter; 5. Conveyor frame; 51. Conveyor chain; 52. Drive motor; 6. Bracket; 7. Protection assembly; 71. Fixed seat; 72. Protection cover; 721. Induction block; 73. Telescopic slot; 74. Compression plate; 75. Air storage tank; 76. First electromagnet; 8. Drive seat; 81. First cleaning frame; 82. Second cleaning frame; 821. First telescopic frame; 822. Second telescopic frame; 823. Third telescopic frame; 83. Cleaning roller; 84. Second electromagnet. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] See also Figure 1-Figure 9The present invention provides a technical solution: an open channel flow detection device based on ultrasound, the detection device includes a Parshall flume 1, a mounting frame 2, an ultrasonic probe 3 and a flow meter 4, a conveying frame 5 is arranged above the Parshall flume 1, a bracket 6 is arranged above the conveying frame 5, the mounting frame 2 is arranged on the bracket 6 and is located above the contraction end of the Parshall flume 1, the ultrasonic probe 3 is arranged on the mounting frame 2, the flow meter 4 is arranged on the outside of the Parshall flume 1, and the ultrasonic probe 3 is connected to the flow meter 4 through a cable. When the present invention is working, the Parshall flume 1 is installed in the ditch, and the propagation time of the ultrasonic signal emitted by the ultrasonic probe 3 in the fluid is measured to obtain the average flow velocity of the fluid (the functions realized by the ultrasonic probe 3 and the flow meter 4 belong to conventional technical means in this field, and the specific structure is not described). Compared with the current detection equipment, the present invention is provided with a retractable and liftable cleaning mechanism, the cleaning mechanism is arranged at the contraction end of the Parshall trough 1, and a conveying mechanism is arranged inside the conveying frame 5. The cleaning mechanism is driven to move in the Parshall trough 1 by the conveying mechanism, and the side walls and the bottom of the Parshall trough 1 are cleaned by the cleaning mechanism to prevent impurities such as mud and sand from accumulating in the Parshall trough 1 and thus changing the cross-sectional area of ​​the Parshall trough 1. Compared with the current method of vibrating the bottom of the Parshall trough 1 to allow impurities to flow away with the water flow, or setting a filter to intercept impurities in the water flow, the cleaning mechanism provided in the present invention can clean some heavy and sticky impurities without interfering with the flow detection of the detection equipment. At the same time, the cleaning mechanism in the present invention has a large cleaning area, and will not cause any obstruction to the flow of the fluid when not working.

[0028] like Figure 1-Figure 5 As shown, the conveying mechanism includes a conveying chain belt 51, and the cleaning mechanism includes a driving seat 8, a first cleaning frame 81 and a second cleaning frame 82. There are two groups of conveying frames 5, and the two groups of conveying frames 5 are relatively arranged at the two ends above the Parshall trough 1. A group of conveying chain belts 51 are arranged in each group of conveying frames 5, and a group of driving motors 52 are arranged below each group of conveying frames 5. Each group of driving motors 52 is connected to a group of conveying chain belts 51. There are two groups of driving seats 8, and the two groups of driving seats 8 are respectively arranged at one end of the two groups of conveying chain belts 51 close to each other. A group of first cleaning frames 8 is arranged below each group of driving seats 8. The first cleaning rack 81 and the second cleaning rack 82 are arranged between the two groups of first cleaning racks 81. During operation, the two groups of driving motors 52 can be started regularly to drive the two groups of first cleaning racks 81 and the second cleaning racks 82 to move in the Parshall trough 1 through the two groups of driving motors 52 and the two groups of conveying racks 5. During the movement of the first cleaning rack 81 and the second cleaning rack 82, the first cleaning rack 81 and the second cleaning rack 82 can clean away impurities such as mud, leaves, etc. attached to the inner wall and bottom of the Parshall trough 1, so as to prevent the cross-section of the Parshall trough 1 from being indirectly changed and the detection accuracy from being affected.

[0029] like Figure 4-Figure 6As shown, the second cleaning frame 82 includes a first telescopic frame 821, a second telescopic frame 822 and a third telescopic frame 823. The first telescopic frame 821 is connected to one group of the first cleaning frames 81, and the second telescopic frame 822 is connected to another group of the first cleaning frames 81. The first telescopic frame 821 and the second telescopic frame 822 are both provided with guide rods. The third telescopic frame 823 is arranged between the first telescopic frame 821 and the second telescopic frame 822. Both ends of the third telescopic frame 823 are movably installed inside the first telescopic frame 821 and the second telescopic frame 822 through guide rods. When the second cleaning frame 82 in the present invention moves in the Parshall trough 1, the distance between the first telescopic frame 821 and the second telescopic frame 822 will change, and the third telescopic frame 823 will shrink into the first telescopic frame 821 and the second telescopic frame 822. Through the above technical solution, it is ensured that when the second cleaning frame 82 moves to the contraction end, throat end and diffusion end of the Parshall trough 1, the second cleaning frame 82 is always in full contact with all areas of the bottom surface of the Parshall trough 1 to avoid cleaning dead corners.

[0030] like Figure 5 As shown, a groove is provided at the bottom of the contraction end of the Parshall trough 1, a lifting groove is provided inside each group of driving seats 8, a second electromagnet 84 is provided at the upper end of each group of lifting grooves, the upper end of each group of first cleaning frames 81 is inserted into the lifting groove, the upper end of each group of first cleaning frames 81 is magnetic, and a cleaning roller 83 is provided at one end of each group of first cleaning frames 81 close to the inner wall of the Parshall trough 1. The present invention controls the lifting and lowering of the first cleaning frame 81 and the second cleaning frame 82 by the second electromagnet 84. When the cleaning mechanism is not working, the second cleaning frame 82 is located in the groove to avoid affecting the flow of liquid in the ditch. When the cleaning mechanism needs to work, the first cleaning frame 81 and the second cleaning frame 82 are controlled to rise by the second electromagnet 84. At this time, the second cleaning frame 82 will extend out of the groove and contact with the bottom of the Parshall trough 1. When the second cleaning frame 82 moves, the bottom of the Parshall trough 1 can be cleaned by the second cleaning frame 82.

[0031] like Figure 1 As shown, when the Parshall cell 1 is installed in the ditch, a plurality of groups of humidity detectors (not shown in the figure) are arranged on the outer wall surface of the Parshall cell 1, and whether leakage occurs between the Parshall cell 1 and the ditch wall surface can be detected by the humidity detectors. Protection components 7 are arranged on the outer sides of the contraction end and the diffusion end of the Parshall cell 1, and the protection components 7 are electrically connected to the plurality of groups of humidity detectors. When leakage occurs between the Parshall cell 1 and the ditch wall surface is detected, the protection components 7 will automatically open, and the leakage can be remedied by the protection components 7.

[0032] like Figure 7 , Figure 8As shown, the protection assembly 7 includes a fixing seat 71 and a protection cover 72. The protection cover 72 is arranged on a side of the fixing seat 71 away from the Parshall cell 1. The fixing seat 71 is provided with a push rod, a telescopic slot 73, a compression plate 74, an air storage tank 75 and a first electromagnet 76. The first electromagnet 76 is arranged at one end of the air storage tank 75. The compression plate 74 is arranged in the air storage tank 75 and has magnetism at one end close to the first electromagnet 76. The telescopic slot 73 is connected to the air storage tank 75. One end of the push rod is connected to the protection cover 72. The other end of the push rod is located in the telescopic groove 73. In the present invention, the gas storage tank 75 is filled with compressed gas. When leakage occurs between the Parshall cell 1 and the wall of the ditch, the first electromagnet 76 will generate a set of magnetic fields that repel the compression plate 74. At this time, the compression plate 74 will squeeze the compressed gas in the gas storage tank 75 into the telescopic groove 73, so that the push rod drives the protective cover 72 to move toward the direction of the ditch wall. The leakage is remedied by the protective cover 72 to prevent the liquid in the ditch from flowing from the outside of the Parshall cell 1.

[0033] like Figure 7 , Figure 8 As shown, both upper and lower ends of the fixing seat 71 are provided with slide grooves, and induction springs are provided in the slide grooves. Both upper and lower ends of the interior of the protective cover 72 are provided with induction blocks 721, and the induction blocks 721 are located in the slide grooves. A piezoelectric sheet is provided at one end of the induction block 721 close to the induction spring. When the protective cover 72 in the present invention moves toward the ditch wall, the induction block 721 will move synchronously, and the piezoelectric sheet will generate a group of electrical signals at this time. The staff can obtain the size of the gap between the Parshall trough 1 and the ditch wall by monitoring the numerical changes of the electrical signals, and then judge the urgency of the maintenance.

[0034] like Fig. 9 As shown, an arc seat 22 and a baffle 25 are provided below the mounting frame 2, and two groups of arc seats 22 are provided. The two groups of arc seats 22 are relatively arranged on the left and right sides of the lower end of the ultrasonic probe 3, and two groups of baffles 25 are provided. The two groups of baffles 25 are relatively arranged on the front and rear sides of the two groups of arc seats 22. A group of arc covers 24 are provided in each group of arc seats 22, and a group of air pumps 21 are provided at the side ends of each group of arc seats 22. Each group of air pumps 21 is connected to the upper and lower ends of the arc seat 22 through the first air duct and the second air duct, and the arc cover 24 is controlled to move in the arc seat 22 by the air pump 21. During the working process of the present invention, liquid splashing and the like are often encountered. Especially when working outdoors, the lens of the ultrasonic probe 3 is easily contaminated. The present invention protects the ultrasonic probe 3 by providing two groups of arc covers 24 to avoid affecting the detection accuracy.

[0035] like Fig. 9As shown, the present invention controls the movement of the arc cover 24 by conveying gas into the arc seat 22 by the air pump 21, that is, when the air pump 21 conveys gas to the lower end of the arc seat 22, the arc cover 24 will retract into the arc seat 22, and when the air pump 21 conveys gas to the upper end of the arc seat 22, the arc cover 24 will extend from the arc seat 22. Through the above technical scheme, the present invention is provided with a group of cleaning cotton 23 at one end where the two groups of arc seats 22 are close to each other, and each group of cleaning cotton 23 is located below the arc cover 24. Every once in a while, the staff can turn on the air pump 21 once, at which time the arc cover 24 will first retract into the arc seat 22, and then extend from the arc seat 22. During the movement of the arc cover 24, the cleaning cotton 23 can automatically clean the arc cover 24, thereby ensuring that the arc cover 24 will never be contaminated by impurities such as droplets or dust.

[0036] Working principle of the present invention: When the present invention is working, it is necessary to set several groups of humidity detectors on the outer wall surface of the Parshall trough 1, and then install the Parshall trough 1 in the ditch, and then measure the propagation time of the ultrasonic signal emitted by the ultrasonic probe 3 in the fluid, so as to obtain the average flow rate of the fluid. During the working process, the staff regularly turns on the two groups of drive motors 52 and the air pump 21, and drives the two groups of first cleaning racks 81 and the second cleaning racks 82 to move in the Parshall trough 1 through the two groups of drive motors 52 and the two groups of conveying racks 5. During the movement of the first cleaning rack 81 and the second cleaning rack 82, the first cleaning rack 81 and the second cleaning rack 82 can clean away impurities such as mud, sand, leaves, etc. attached to the inner wall and bottom of the Parshall trough 1, so as to prevent the Parshall trough from being damaged. The cross section of the Parshall trough 1 is indirectly changed, which affects the detection accuracy. The arc cover 24 is driven by the air pump 21 to move in the arc seat 22. During the movement of the arc cover 24, the cleaning cotton 23 can automatically clean the arc cover 24, thereby ensuring that the arc cover 24 will never be contaminated by impurities such as droplets or dust. During operation, if leakage occurs between the Parshall trough 1 and the ditch wall, the humidity detector will send a set of signals to the first electromagnet 76. At this time, the first electromagnet 76 will drive the compression plate 74 to squeeze the compressed gas in the air storage tank 75, so that the top rod drives the protective cover 72 to move toward the ditch wall, and the leakage is remedied by the protective cover 72 to prevent the liquid in the ditch from flowing from the outside of the Parshall trough 1.

[0037] Although the embodiments of the present invention have been shown and described, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, substitute and vary the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. An open channel flow detection device based on ultrasonic wave, characterized in that: The detection device comprises a Parshall trough (1), a mounting frame (2), an ultrasonic probe (3) and a flow meter (4); a conveying frame (5) is arranged above the Parshall trough (1); a bracket (6) is arranged above the conveying frame (5); the mounting frame (2) is arranged on the bracket (6) and is located above the contraction end of the Parshall trough (1); the ultrasonic probe (3) is arranged on the mounting frame (2); the flow meter (4) is arranged outside the Parshall trough (1); the ultrasonic probe (3) is connected to the flow meter (4) via a cable; a cleaning mechanism is arranged inside the contraction end of the Parshall trough (1); a conveying mechanism is arranged inside the conveying frame (5); the cleaning mechanism is connected to the conveying mechanism; the cleaning mechanism is driven by the conveying mechanism to move inside the Parshall trough (1); the cleaning mechanism has telescopic and lifting functions; A plurality of groups of humidity detectors are arranged on the outer wall surface of the Parshall cell (1), and protective components (7) are arranged on the outer sides of the contraction end and the diffusion end of the Parshall cell (1), and the protective components (7) are electrically connected to the plurality of groups of humidity detectors; The protection assembly (7) comprises a fixing seat (71) and a protection cover (72), wherein the protection cover (72) is arranged on a side of the fixing seat (71) away from the Parshall cell (1), and a push rod, a telescopic slot (73), a compression plate (74), an air storage tank (75) and a first electromagnet (76) are arranged inside the fixing seat (71), wherein the first electromagnet (76) is arranged at one end of the air storage tank (75), the compression plate (74) is arranged in the air storage tank (75) and has a magnetic property at one end close to the first electromagnet (76), the telescopic slot (73) is connected to the air storage tank (75), one end of the push rod is connected to the protection cover (72), and the other end of the push rod is located in the telescopic slot (73); The fixing seat (71) is provided with a slide groove at both upper and lower ends, and a sensing spring is provided in the slide groove. The protective cover (72) is provided with a sensing block (721) at both upper and lower ends, and the sensing block (721) is located in the slide groove. A piezoelectric sheet is provided at one end of the sensing block (721) close to the sensing spring.

2. The ultrasonic open channel flow detection device according to claim 1, characterized in that: The conveying mechanism comprises a conveying chain belt (51), and the cleaning mechanism comprises a driving seat (8), a first cleaning frame (81) and a second cleaning frame (82). The conveying frame (5) is provided with two groups, and the two groups of conveying frames (5) are arranged at two ends above the Parshall trough (1) in a relative manner. A group of conveying chains (51) is arranged in each group of conveying frames (5), and a group of driving motors (52) is arranged below each group of conveying frames (5). Each group of driving motors (52) is connected to a group of conveying chains (51). The driving seat (8) is provided with two groups, and the two groups of driving seats (8) are respectively arranged at one end of the two groups of conveying chains (51) close to each other. A group of first cleaning frames (81) is arranged below each group of driving seats (8), and the second cleaning frame (82) is arranged between the two groups of first cleaning frames (81).

3. The ultrasonic open channel flow detection device according to claim 2, characterized in that: A groove is provided at the bottom of the contraction end of the Parshall trough (1); the second cleaning frame (82) comprises a first telescopic frame (821), a second telescopic frame (822) and a third telescopic frame (823); the first telescopic frame (821) is connected to one group of the first cleaning frames (81); the second telescopic frame (822) is connected to another group of the first cleaning frames (81); guide rods are provided inside the first telescopic frame (821) and the second telescopic frame (822); the third telescopic frame (823) is provided between the first telescopic frame (821) and the second telescopic frame (822); and two ends of the third telescopic frame (823) are movably mounted inside the first telescopic frame (821) and the second telescopic frame (822) via guide rods.

4. The ultrasonic open channel flow detection device according to claim 2, characterized in that: Each group of the driving seats (8) is provided with a lifting slot inside, and a second electromagnet (84) is provided at the upper end of each group of the lifting slots. The upper end of each group of the first cleaning racks (81) is inserted into the lifting slot and has magnetism. A cleaning roller (83) is provided at one end of each group of the first cleaning racks (81) close to the inner wall of the Parshall slot (1).

5. The ultrasonic open channel flow detection device according to claim 1, characterized in that: An arc seat (22) and a baffle (25) are arranged below the mounting frame (2). Two groups of the arc seat (22) are arranged, and the two groups of the arc seat (22) are arranged relatively on the left and right sides of the lower end of the ultrasonic probe (3). Two groups of the baffle (25) are arranged, and the two groups of the baffle (25) are arranged relatively on the front and rear sides of the two groups of the arc seat (22). A group of arc covers (24) are arranged in each group of the arc seat (22). A group of air pumps (21) are arranged at the side ends of each group of the arc seat (22). Each group of the air pumps (21) is connected to the upper and lower ends of the arc seat (22) through a first air guide tube and a second air guide tube, and the arc cover (24) is controlled to move in the arc seat (22) through the air pump (21).

6. The ultrasonic open channel flow detection device according to claim 5, characterized in that: A group of cleaning cotton (23) is provided at one end of the two groups of arc-shaped seats (22) close to each other, and each group of cleaning cotton (23) is located below the arc-shaped cover (24).

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