Ultrasonic flowmeter

Abstract

To enable impact on ultrasonic waves propagated through an ultrasonic wave pathway shaped like the letter W to be suppressed more than possible before.SOLUTION: An ultrasonic flowmeter comprises: a first ultrasonic wave transceiver 102-1 attached to the upstream side of a piping 101; a second ultrasonic wave transceiver 102-2 attached to the downstream side of the piping 101; and a structure 103a for reflection which is installed to an inner wall of the piping 101 facing the first ultrasonic wave transceiver 102-1 and the second ultrasonic wave transceiver 102-2. The first ultrasonic wave transceiver 102-1 and the second ultrasonic wave transceiver 102-2 form an ultrasonic wave pathway shaped like the letter W in the piping 101, and the structure 103a for reflection shuts off the ultrasonic wave propagating through an ultrasonic wave pathway shaped like the letter V in the piping 101.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an ultrasonic flowmeter that uses ultrasonic waves to measure the flow rate of a fluid that is a measurement target. [Background technology]

[0002] Conventionally, ultrasonic flowmeters that use ultrasonic waves to measure the flow rate of a fluid to be measured are known. Among these ultrasonic flowmeters, a W-shaped ultrasonic path is formed in a pipe in which ultrasonic waves are reflected three times. In an ultrasonic flowmeter in which a W-shaped ultrasonic path is formed, it is known that in addition to ultrasonic waves that propagate through the W-shaped ultrasonic path, ultrasonic waves that propagate through a V-shaped ultrasonic path, in which the ultrasonic waves are reflected once, are also transmitted. As a method for suppressing ultrasonic waves propagating through this V-shaped ultrasonic path, for example, the methods disclosed in Patent Documents 1 and 2 have been proposed.

[0003] In the method disclosed in Patent Document 1, in order to reduce or eliminate noise signals, which are ultrasonic waves propagating through a V-shaped ultrasonic path, a step structure is provided on the reflection surface of the V-shaped ultrasonic path, and ultrasonic waves reflected at the low step part and ultrasonic waves reflected at the high step part are caused to annihilate each other.

[0004] Furthermore, in the method disclosed in Patent Document 2, the ultrasonic transmitter / receiver is arranged offset with respect to the geometric arrangement of the W-shaped ultrasonic path route. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2944206 [Patent Document 2] Patent No. 2974770 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the method disclosed in Patent Document 1, the initial part of the ultrasonic wave reflected at the high part of the step travels ahead of the ultrasonic wave reflected at the low part of the step. Therefore, in this method, there are ultrasonic waves that cannot be annihilated and reach the ultrasonic transmitter / receiver, and there is a possibility that the ultrasonic waves propagating along the W-shaped ultrasonic path route will be affected.

[0007] In addition, in the method disclosed in Patent Document 2, although the amount of ultrasonic waves in the V-shaped ultrasonic path reaches the ultrasonic transmitter / receiver, the ultrasonic waves may be affected by the W-shaped ultrasonic path.

[0008] In this way, the conventional method cannot completely remove ultrasonic waves propagated through the V-shaped ultrasonic path, and may affect ultrasonic waves propagated through the W-shaped ultrasonic path to some extent.

[0009] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an ultrasonic flowmeter that can suppress the effects on ultrasonic waves propagating through a W-shaped ultrasonic path compared to conventional techniques. [Means for solving the problem]

[0010] The ultrasonic flowmeter of the present disclosure comprises a first ultrasonic transceiver attached to the upstream side of a pipe, a second ultrasonic transceiver attached to the downstream side of the pipe, and a reflection structure provided on an inner wall of the pipe facing the first ultrasonic transceiver and the second ultrasonic transceiver, wherein the first ultrasonic transceiver and the second ultrasonic transceiver form a W-shaped ultrasonic path route within the pipe, and the reflection structure blocks ultrasonic waves propagating along a V-shaped ultrasonic path route within the pipe. Effect of the Invention

[0011] According to the present disclosure, since it is configured as described above, it is possible to suppress the influence on ultrasonic waves propagating through the W-shaped ultrasonic path route, as compared to the conventional art. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a configuration example of an ultrasonic flowmeter according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing a configuration example of a reflecting structure in the first embodiment, and is an enlarged cross-sectional view showing a configuration example of a part of an ultrasonic flowmeter. [Diagram 3] 4 is a cross-sectional view for explaining an example of a basic operation of a calculation unit in the first embodiment. FIG. [Figure 4] 5A to 5C are cross-sectional views for explaining a design example of a reflecting structure in the first embodiment. [Diagram 5] 5A to 5C are cross-sectional views for explaining a design example of a reflecting structure in the first embodiment. [Figure 6] FIG. 1 is a diagram for explaining the effect of the ultrasonic flowmeter of embodiment 1, showing an example of a received waveform when the ultrasonic flowmeter does not have a reflecting structure (in the case of a conventional ultrasonic flowmeter) and an example of a received waveform when the ultrasonic flowmeter has a reflecting structure (in the case of the ultrasonic flowmeter of embodiment 1). [Figure 7] FIG. 1 is a diagram for explaining the effect of the ultrasonic flowmeter of embodiment 1, showing an example of the flow characteristics when the ultrasonic flowmeter does not have a reflecting structure (in the case of a conventional ultrasonic flowmeter) and when the ultrasonic flowmeter has a reflecting structure (in the case of the ultrasonic flowmeter of embodiment 1). [Figure 8] FIG. 11 is a cross-sectional view showing a configuration example of an ultrasonic flowmeter according to a second embodiment. [Figure 9] 11A to 11C are cross-sectional views for explaining a design example of a reflecting structure in the second embodiment. [Figure 10] 13A to 13C are diagrams for explaining design examples of the reflection structure in the second embodiment. [Figure 11] 11A to 11C are cross-sectional views for explaining a design example of a reflecting structure in the second embodiment. [Figure 12] FIG. 11 is a cross-sectional view showing a configuration example of an ultrasonic flowmeter according to a third embodiment. [Figure 13] 13A to 13C are cross-sectional views for explaining design examples of the reflecting structure in the third embodiment. [Figure 14] 13A to 13C are cross-sectional views for explaining design examples of the reflecting structure in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments will be described in detail with reference to the drawings. Embodiment 1 The ultrasonic flowmeter 1 measures the flow rate of a fluid to be measured by using ultrasonic waves. As shown in Fig. 1, the ultrasonic flowmeter 1 includes a pipe 101, a pair of ultrasonic transmitters and receivers 102 (a first ultrasonic transmitter and receiver 102-1 and a second ultrasonic transmitter and receiver 102-2), a reflecting structure 103a, and a calculation unit 104 (not shown).

[0014] In FIG. 1, the solid arrow indicated by reference numeral 11 indicates a W-shaped ultrasonic path, and the dashed arrow indicated by reference numeral 12 indicates a V-shaped ultrasonic path.

[0015] The pipe 101 is a pipe through which a fluid to be measured by the ultrasonic flowmeter 1 flows.

[0016] The first ultrasonic transmitter / receiver 102-1 is attached to the upstream side of the side wall of the pipe 101, and is an ultrasonic transducer that alternately transmits and receives ultrasonic waves to and from the second ultrasonic transmitter / receiver 102-2 within the pipe 101. That is, the first ultrasonic transmitter / receiver 102-1 transmits ultrasonic waves to the downstream side (second ultrasonic transmitter / receiver 102-2) within the pipe 101, and receives ultrasonic waves from the downstream side (second ultrasonic transmitter / receiver 102-2) as a reception signal. The reception signal received by the first ultrasonic transmitter / receiver 102-1 is output to the calculation unit 104.

[0017] The second ultrasonic transmitter / receiver 102-2 is attached to the downstream side of the sidewall of the pipe 101, and is an ultrasonic transducer that alternately transmits and receives ultrasonic waves to and from the first ultrasonic transmitter / receiver 102-1 within the pipe 101. That is, the second ultrasonic transmitter / receiver 102-2 transmits ultrasonic waves to the upstream side (first ultrasonic transmitter / receiver 102-1) within the pipe 101 according to the control of the calculation unit 104, and receives ultrasonic waves from the upstream side (first ultrasonic transmitter / receiver 102-1) as a reception signal. The reception signal received by the second ultrasonic transmitter / receiver 102-2 is output to the calculation unit 104.

[0018] The first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 are disposed on the same wall surface side of the pipe 101. Moreover, the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 are arranged in the piping 101 so as to form a W-shaped ultrasonic path.

[0019] The reflecting structure 103a is provided on an inner wall facing the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 in the pipe 101. The reflecting structure 103a blocks (reflects) ultrasonic waves propagating through a V-shaped ultrasonic path in the pipe 101.

[0020] The reflecting structure 103a has a plane perpendicular (including substantially perpendicular) to the V-shaped ultrasonic path in the pipe 101. In the ultrasonic flowmeter 1 according to the first embodiment, the reflecting structure 103a is a single protrusion protruding from the inner wall of the pipe 101. In the example of Fig. 1, the reflecting structure 103a has a triangular cross-sectional shape.

[0021] Also, as shown in Figure 2, the width of the reflection structure 103a (the width indicated by symbol b in Figure 1) is designed to be such that it does not interfere with the ultrasonic wave width propagating through the W-shaped ultrasonic path route in the piping 101, but blocks the ultrasonic wave width propagating through the V-shaped ultrasonic path route in the piping 101. Also, as shown in FIG. 2, the reflection structure 103a is designed to have a height (height indicated by symbol H1 in FIG. 1) that blocks the width of ultrasonic waves propagating along the V-shaped ultrasonic path in the piping 101. In FIG. 2, reference numeral 21 denotes an ultrasonic wave width propagating along a W-shaped ultrasonic path, and reference numeral 22 denotes an ultrasonic wave width propagating along a V-shaped ultrasonic path.

[0022] A specific design example of this reflecting structure 103a will be described later.

[0023] The calculation unit 104 calculates the flow rate of the fluid to be measured based on the transmission and reception results by the first ultrasonic transmitter / receiver 102-1 and the transmission and reception results by the second ultrasonic transmitter / receiver 102-2.

[0024] The calculation unit 104 is realized by a processing circuit such as a system LSI (Large Scale Integration), or a CPU (Central Processing Unit) that executes a program stored in a memory or the like.

[0025] Next, a basic operation example of the calculation unit 104 in the first embodiment will be described with reference to Fig. 3. In order to simplify the description, Fig. 3 shows a configuration in which the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 of the ultrasonic flowmeter 1 are arranged relative to each other, and ultrasonic waves are directly transmitted and received without being reflected.

[0026] First, the calculation unit 104 calculates a first propagation time, which is the propagation time of an ultrasonic wave propagating from the upstream to the downstream in the pipe 101, based on the transmission and reception result by the first ultrasonic transmitter / receiver 102-1 and the transmission and reception result by the second ultrasonic transmitter / receiver 102-2. In Fig. 3, t1 indicates the first propagation time. Furthermore, the calculation unit 104 calculates a second propagation time, which is the propagation time of the ultrasonic wave propagating from downstream to upstream in the pipe 101, based on the transmission and reception result by the first ultrasonic transmitter / receiver 102-1 and the transmission and reception result by the second ultrasonic transmitter / receiver 102-2. In Fig. 3, t2 indicates the second propagation time.

[0027] Here, the first propagation time (t1) is expressed by the following formula (1), and the second propagation time (t2) is expressed by the following formula (2). In formulas (1) and (2), L indicates the propagation distance of the ultrasonic wave, and θ indicates the propagation angle of the ultrasonic wave with respect to the flow direction of the fluid. Also, c in formulas (1) and (2) is expressed by the following formula (3). TIFF2025014543000002.tif78166

[0028] Then, the calculation unit 104 calculates the flow velocity (V) of the fluid flowing through the pipe 101 based on the time difference between the calculated first propagation time (t1) and second propagation time (t2) and the propagation distance (L) of the ultrasonic wave. Then, the calculation unit 104 calculates the flow rate (Q) of the fluid flowing through the pipe 101 based on the calculated flow velocity (V) and the cross-sectional area (S) of the pipe 101 .

[0029] Here, the flow velocity (V) of the fluid flowing through the pipe 101 is expressed by the following formula (4), and the flow rate (Q) of the fluid flowing through the pipe 101 is expressed by the following formula (5). TIFF2025014543000003.tif37166

[0030] Next, a design example of the reflecting structure 103a will be described with reference to FIGS. Here, x1 is expressed by the following formula (6), x2 is expressed by the following formula (7), and B1 is expressed by the following formulas (8) and (9). Note that x1 is the distance between the entrance / exit point for the ultrasonic transmitter / receiver 102 in the pipe 101 and the reflection point closest to the ultrasonic transmitter / receiver 102 in the W-shaped ultrasonic path route. Also, x2 is half the width of the ultrasonic wave propagating through the W-shaped ultrasonic path route. Also, B1 is a width that does not interfere with the ultrasonic wave width propagating through the W-shaped ultrasonic path route and blocks the ultrasonic wave width propagating through the V-shaped ultrasonic path route. TIFF2025014543000004.tif32166

[0031] Moreover, θ2 is expressed by the following formula (10), θ3 is expressed by the following formula (11), B2 is expressed by the following formula (12), and H1 is expressed by the following formula (13). Here, θ2 is the incident / emitted angle in the V-shaped ultrasonic path. θ3 is the angle of the plane in the reflection structure 103a. B2 is the width that blocks the ultrasonic wave width propagating through the V-shaped ultrasonic path. H1 is the height that blocks the ultrasonic wave width propagating through the V-shaped ultrasonic path. TIFF2025014543000005.tif30166

[0032] The reflecting structure 103a is designed so that the width (b) satisfies B1>b>B2. Moreover, the reflecting structure 103a has a height H1.

[0033] In this manner, in the ultrasonic flowmeter 1 according to the first embodiment, a reflection structure 103a for blocking ultrasonic waves propagating along a V-shaped ultrasonic path in the pipe 101 is provided on an inner wall of the pipe 101 facing the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2. That is, in the ultrasonic flowmeter 1 according to the first embodiment, a method is adopted in which ultrasonic waves propagated along a V-shaped ultrasonic path are attenuated or eliminated from interference after reflection as disclosed in Patent Document 1 or Patent Document 2, but a structure is provided on the reflection surface to directly block ultrasonic waves (reflect them in the incident direction).

[0034] As a result, in the ultrasonic flowmeter 1 according to the first embodiment, it is possible to prevent the ultrasonic waves propagated through the V-shaped ultrasonic path in the pipe 101 from being received by the ultrasonic transmitter / receiver 102. As a result, as shown in Fig. 6 for example, in the ultrasonic flowmeter 1 according to the first embodiment, the ultrasonic flowmeter 1 is not affected by the ultrasonic waves propagated through the V-shaped ultrasonic path compared to the conventional method, and therefore the signal intensity of the ultrasonic waves propagated through the W-shaped ultrasonic path increases. In FIG. 6, reference numeral 61 indicates an example of the signal strength of ultrasonic waves propagating along a W-shaped ultrasonic path in the case of a conventional ultrasonic flowmeter 1 that does not have a reflection structure 103a, and reference numeral 62 indicates an example of the signal strength of ultrasonic waves propagating along a W-shaped ultrasonic path in the case of an ultrasonic flowmeter 1 according to embodiment 1 that has a reflection structure 103a.

[0035] 7, in the conventional ultrasonic flowmeter 1 that does not have the reflecting structure 103a, the flow characteristics deteriorate due to changes in water temperature. In contrast, in the ultrasonic flowmeter 1 according to the first embodiment that has the reflecting structure 103a, it is possible to avoid deterioration of the flow characteristics even due to changes in water temperature. In Fig. 7, the two waveforms indicated by reference numeral 71 show waveforms in the case of a conventional ultrasonic flowmeter 1 that does not have a reflecting structure 103a, the waveform indicated by black circles is when the fluid temperature is 5°C, and the waveform indicated by black squares is when the fluid temperature is 20°C. In addition, in Fig. 7, the two waveforms indicated by reference numeral 72 show waveforms in the case of an ultrasonic flowmeter 1 according to embodiment 1 that has a reflecting structure 103a, the waveform indicated by black circles is when the fluid temperature is 5°C, and the waveform indicated by black squares is when the fluid temperature is 20°C.

[0036] As described above, according to this embodiment 1, the ultrasonic flowmeter 1 comprises a first ultrasonic transmitter / receiver 102-1 attached to the upstream side of the piping 101, a second ultrasonic transmitter / receiver 102-2 attached to the downstream side of the piping 101, and a reflection structure 103a provided on an inner wall of the piping 101 facing the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2, and the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 form a W-shaped ultrasonic path route within the piping 101, and the reflection structure 103a blocks ultrasonic waves propagating along a V-shaped ultrasonic path route within the piping 101. In addition, in the ultrasonic flowmeter 1 of embodiment 1, the reflection structure 103a has a plane perpendicular to the V-shaped ultrasonic path path in the piping 101, and its width is designed to block the ultrasonic width propagating through the V-shaped ultrasonic path path in the piping 101 without interfering with the ultrasonic width propagating through the W-shaped ultrasonic path path in the piping 101, and its height is designed to block the ultrasonic width propagating through the V-shaped ultrasonic path path in the piping 101. In the ultrasonic flowmeter 1 according to the first embodiment, the reflecting structure 103a is a protrusion protruding from the inner wall of the pipe 101. As a result, the ultrasonic flowmeter 1 according to the first embodiment can suppress the influence on the signal propagated through the W-shaped ultrasonic path compared to the conventional one. As a result, the ultrasonic flowmeter 1 according to the first embodiment can improve the measurement accuracy of the flow rate compared to the conventional one.

[0037] Embodiment 2 In the ultrasonic flowmeter 1 according to the first embodiment, a case where a reflection structure 103a that is a single protrusion is provided is shown. In contrast, in the ultrasonic flowmeter 1 according to the second embodiment, a case where a reflection structure 103b that is a plurality of protrusions is provided is shown. Fig. 8 is a diagram showing a configuration example of an ultrasonic flowmeter 1 according to embodiment 2. In the ultrasonic flowmeter 1 according to embodiment 2 shown in Fig. 8, the reflection structure 103a is changed to a reflection structure 103b in the ultrasonic flowmeter 1 according to embodiment 1 shown in Fig. 1. The other configuration example of the ultrasonic flowmeter 1 according to embodiment 2 shown in Fig. 8 is similar to the configuration example of the ultrasonic flowmeter 1 according to embodiment 1 shown in Fig. 1, and the same reference numerals are used to denote the same components, and the description thereof will be omitted.

[0038] The reflecting structure 103b is provided on an inner wall facing the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 in the pipe 101. The reflecting structure 103b blocks (reflects) ultrasonic waves propagating through a V-shaped ultrasonic path in the pipe 101.

[0039] The reflecting structure 103b has a plane perpendicular (including the meaning of approximately perpendicular) to the V-shaped ultrasonic path in the pipe 101. In the ultrasonic flowmeter 1 according to the second embodiment, the reflecting structure 103b is a plurality of protrusions protruding from the inner wall of the pipe 101. In the example of Fig. 8, the cross-sectional shape of the protrusions of the reflecting structure 103b is triangular.

[0040] In addition, the width of the reflection structure 103b is designed to be such that it does not interfere with the ultrasonic width propagating through the W-shaped ultrasonic path in the piping 101, but blocks the ultrasonic width propagating through the V-shaped ultrasonic path in the piping 101. Moreover, the reflection structure 103b is designed to have a height that blocks the width of ultrasonic waves propagating along the V-shaped ultrasonic path in the pipe 101.

[0041] Next, design examples of the reflecting structure 103b in the second embodiment will be described with reference to FIGS.

[0042] Here, the cross-sectional area (S1) of the pipe 101 in the first region and the third region shown in Fig. 9 is expressed by the following formula (14). Also, the cross-sectional area (S2) of the second region shown in Fig. 9 is expressed by the following formula (15). The first region is indicated by reference numeral 91 in Fig. 9, and is a region in the pipe 101 where the first ultrasonic transmitter-receiver 102-1 is located. The second region is indicated by reference numeral 92 in Fig. 9, and is a region in the pipe 101 where the reflecting structure 103b is located. The third region is indicated by reference numeral 93 in Fig. 9, and is a region in the pipe 101 where the second ultrasonic transmitter-receiver 102-2 is located. In addition, in formulas (14) and (15), A represents the flow path width, and H represents the flow path height. TIFF2025014543000006.tif16166

[0043] In the reflection structure 103b in the second embodiment, as shown in the following formula (16), the straight pipe loss (ΔP1, ΔP2, ΔP3), the reduction loss (ΔP sc 01,ΔP sc 12), expansion loss (ΔP sd 23,ΔP sd 34) and the total pressure loss is the target pressure loss (ΔP goal The height (H1) is designed so that the height is equal to or less than ΔP sc 12+ΔP2+ΔP sd 34) item. TIFF2025014543000007.tif11166

[0044] The straight pipe loss (ΔP) is expressed by the following equations (17) to (20). In equations (17) to (20), S represents the cross-sectional area, l represents the flow path length, V represents the flow velocity in a straight pipe, ρ represents the density, μ represents the viscosity coefficient, Re represents the Reynolds number, and λ represents the pipe friction coefficient. TIFF2025014543000008.tif33166

[0045] In addition, the shrinkage loss (ΔP sc ) is expressed by the following equations (21) and (22). In equations (21) and (22), S1 represents the larger cross-sectional area, S2 represents the smaller cross-sectional area, V2 represents the flow velocity of the smaller cross-sectional area, and ζ c indicates the loss factor. Note that the cross-sectional area ratio (S2 / S1) and the loss factor (ζ c ) The relationship between the two is shown in FIG. TIFF2025014543000009.tif19166

[0046] In addition, the expansion loss (ΔP sd ) is expressed by the following equations (23) and (24). In equations (23) and (24), S1 represents the smaller cross-sectional area, S2 represents the larger cross-sectional area, V1 represents the flow velocity of the smaller cross-sectional area, and ζ d indicates the loss factor. TIFF2025014543000010.tif19166

[0047] The number (N) of the reflecting structures 103b is designed based on the following expressions (25) and (26). In addition, in formula (25), B3 is the width of one protrusion of the reflecting structure 103b. TIFF2025014543000011.tif18166

[0048] As described above, according to the second embodiment, the reflecting structure 103b is provided with a plurality of protrusions. As a result, the ultrasonic flowmeter 1 according to the second embodiment can have a lower height of the reflecting structure 103b than the ultrasonic flowmeter 1 according to the first embodiment, and the narrowing of the cross-sectional area can be reduced. Also, the ultrasonic flowmeter 1 according to the second embodiment does not cause severe disturbance of the flow lines compared to the ultrasonic flowmeter 1 according to the first embodiment.

[0049] Embodiment 3 In the ultrasonic flowmeter 1 according to the second embodiment, a reflecting structure 103b having a plurality of protrusions is provided. In contrast, in the ultrasonic flowmeter 1 according to the third embodiment, a reflecting structure 103c having a plurality of grooves formed in the pipe 101 is provided. Fig. 12 is a diagram showing a configuration example of an ultrasonic flowmeter 1 according to an embodiment 3. In the ultrasonic flowmeter 1 according to the embodiment 3 shown in Fig. 12, the reflection structure 103b is changed to a reflection structure 103c in the ultrasonic flowmeter 1 according to the embodiment 2 shown in Fig. 8. The other configuration example of the ultrasonic flowmeter 1 according to the embodiment 3 shown in Fig. 12 is similar to the configuration example of the ultrasonic flowmeter 1 according to the embodiment 2 shown in Fig. 8, and the same reference numerals are used to denote the same components, and the description thereof will be omitted.

[0050] The reflecting structure 103c is provided on an inner wall facing the first ultrasonic transmitter / receiver 102-1 and the second ultrasonic transmitter / receiver 102-2 in the pipe 101. The reflecting structure 103c blocks (reflects) ultrasonic waves propagating through a V-shaped ultrasonic path in the pipe 101.

[0051] The reflecting structure 103c has a plane perpendicular (including substantially perpendicular) to the V-shaped ultrasonic path in the pipe 101. In the ultrasonic flowmeter 1 according to the third embodiment, the reflecting structure 103c is a plurality of grooves formed on the inner wall of the pipe 101. In the example of Fig. 12, the cross-sectional shape of the grooves of the reflecting structure 103c is triangular.

[0052] In addition, the width of the reflection structure 103c is designed to be such that it does not interfere with the ultrasonic width propagating through the W-shaped ultrasonic path in the piping 101, but blocks the ultrasonic width propagating through the V-shaped ultrasonic path in the piping 101. Moreover, the height (depth) of the reflection structure 103c is designed to be a height that blocks the width of ultrasonic waves propagating along the V-shaped ultrasonic path in the pipe 101.

[0053] Next, a design example of the reflecting structure 103c in the third embodiment will be described with reference to FIGS.

[0054] In the reflection structure 103c in the third embodiment, as shown in the following formula (27), the straight pipe loss (ΔP1, ΔP2, ΔP3), the reduction loss (ΔP sc 01,ΔP sc 23), expansion loss (ΔP sd 12,ΔP sd 34) and the total pressure loss is the target pressure loss (ΔP goal The height (H1) is designed so that the height is equal to or less than ΔP sd 12+ΔP2+ΔP sc 23) item. The first region is indicated by reference numeral 131 in Fig. 13, and is a region in the pipe 101 where the first ultrasonic transmitter-receiver 102-1 is present. The second region is indicated by reference numeral 132 in Fig. 13, and is a region in the pipe 101 where the reflecting structure 103c is present. The third region is indicated by reference numeral 133 in Fig. 13, and is a region in the pipe 101 where the second ultrasonic transmitter-receiver 102-2 is present. TIFF2025014543000012.tif11166

[0055] As described above, according to the third embodiment, the reflecting structure 103c is a plurality of grooves formed on the inner wall of the pipe 101. As a result, the ultrasonic flowmeter 1 according to the third embodiment does not narrow the cross-sectional area of ​​the pipe 101 compared to the ultrasonic flowmeter 1 according to the second embodiment, and it is possible to prevent the flow line from being severely disturbed.

[0056] It should be noted that the embodiments may be freely combined, or any of the components in each embodiment may be modified, or any of the components in each embodiment may be omitted. [Explanation of symbols]

[0057] 1 Ultrasonic flow meter 101 Piping 102 Ultrasonic Transmitter / Receiver 102-1 First ultrasonic transmitter / receiver 102-2 Second ultrasonic transmitter / receiver 103a,103b,103c Reflection structure 104 Arithmetic section

Claims

1. a first ultrasonic transmitter / receiver attached to an upstream side of the piping; A second ultrasonic transmitter / receiver is attached to the downstream side of the pipe; a reflection structure provided on an inner wall of the pipe facing the first ultrasonic transmitter-receiver and the second ultrasonic transmitter-receiver, The first ultrasonic transmitter / receiver and the second ultrasonic transmitter / receiver form a W-shaped ultrasonic path in the piping, The reflection structure blocks ultrasonic waves propagating along a V-shaped ultrasonic path in the piping.

1. An ultrasonic flow meter comprising:

2. The reflection structure includes: A plane perpendicular to the V-shaped ultrasonic path in the pipe, The width is designed to be such that it does not interfere with the ultrasonic width propagating through the W-shaped ultrasonic path in the piping, and blocks the ultrasonic width propagating through the V-shaped ultrasonic path in the piping; The height is designed to block the ultrasonic wave width propagating along the V-shaped ultrasonic path in the piping.

2. The ultrasonic flowmeter according to claim 1.

3. The reflection structure is a protrusion protruding from the inner wall of the pipe.

3. The ultrasonic flowmeter according to claim 1 or 2.

4. The reflection structure is provided with a plurality of the protrusions.

4. The ultrasonic flowmeter according to claim 3.

5. The reflecting structure is a plurality of grooves formed on the inner wall of the pipe.

3. The ultrasonic flowmeter according to claim 1 or 2.

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