Flow sensor of high-precision ultrasonic water meter

Abstract

The flow sensor is characterized in that the flow sensor comprises a measuring pipe and at least one pair of ultrasonic transducers, the measuring pipe is provided with two connecting sections distributed in the flowing direction of the measuring pipe and a reducing section communicated between the two connecting sections, and the flowing section of the reducing section is smaller than that of the connecting sections; the two ultrasonic transducers in each pair are installed at the connectors on the two sides of the measuring tube respectively, each ultrasonic transducer is provided with an ultrasonic receiving and transmitting face extending into the measuring tube, a gland is plugged on the side, away from the measuring tube, of each ultrasonic transducer, and the glands are detachably connected with the connectors. And the measurement accuracy can be effectively improved.

Description

Technical Field

[0001] The invention relates to the field of instrument and meter measuring devices, and in particular to a flow sensor for a high-precision ultrasonic water meter. Background Art

[0002] At present, in the practical application of ultrasonic water meters, the flow sensors of ultrasonic water meters are divided into micro-power consumption type and high-power type. Micro-power consumption ultrasonic water meters can complete 10 years of measurement with only the commonly used 18505 lithium battery, while high-power ultrasonic water meters need to rely on external power supply to perform measurement functions for more than 1 month. The sensor of the high-power ultrasonic water meter is usually packaged with a copper alloy or austenitic stainless steel of more than 2mm. The thick shell enables it to cope with various complex medium liquids and make various flexible arrangements according to the site; the sensor of the micro-power consumption ultrasonic water meter usually uses titanium alloy or austenitic stainless steel below 0.1mm as packaging protection. Due to the thin package, the micro-power consumption sensor cannot be used in the application of highly corrosive liquid conditions. In a 20% NaOH solution at 50℃, the annual corrosion thickness of austenitic stainless steel 316L material is 0.12mm; the too thin metal material also limits the shape and installation structure of the sensor; making the micro-power consumption ultrasonic water meter only used for relatively clean water flow measurement.

[0003] With the development of wireless communication technologies such as NB-Iot and LTE-Cat1, micro-power consumption ultrasonic water meters have a natural synergistic relationship with wireless communication technologies because they do not require an external power supply.

[0004] The greater the measuring distance of the ultrasonic sensor along the flow direction, the greater the medium flow velocity in the measuring pipe section area, and the higher the measurement accuracy. Therefore, how to achieve a larger measuring distance in the direction of fluid flow within the limited length of the meter body pipe section is the core of ultrasonic measurement. However, the package of the micro-power type ultrasonic water meter sensor is too thin, which limits its single structure and makes it difficult to increase its measuring distance.

[0005] The above-mentioned deficiencies in the prior art are difficult problems that need to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to provide a high-precision flow sensor for an ultrasonic water meter to solve the problems existing in the above-mentioned prior art and effectively improve the measurement accuracy.

[0007] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention provides a flow sensor for a high-precision ultrasonic water meter, comprising a measuring tube and at least two pairs of ultrasonic transducers, the measuring tube being provided with two connecting sections distributed along its flow direction and a reduced diameter section connected between the two connecting sections, the flow cross-section of the reduced diameter section being smaller than that of the connecting section, and the reduced diameter section being provided with interfaces on both sides along its radial direction, the two ultrasonic transducers in each pair being respectively installed at the interfaces on both sides of the measuring tube, the ultrasonic transducers being provided with an ultrasonic transmitting and receiving surface extending into the measuring tube, the side of the ultrasonic transducer facing away from the measuring tube being blocked with a pressure cover, and the pressure cover being detachably connected to the interface.

[0008] Preferably, the flow cross-sectional area of ​​the reduced diameter section accounts for 40% to 80% of the flow cross-sectional area of ​​the connecting section.

[0009] Preferably, the reduced diameter section is a flat structure, and the interfaces are distributed on both sides of the reduced diameter section in the long side direction.

[0010] Preferably, the axis of the interface is perpendicular to the axial direction of the reduced diameter section, and the ultrasonic transceiver surface is distributed at an angle to the axis of the interface.

[0011] Preferably, the ultrasonic transceiver surface is distributed at an acute angle to the axis of the interface.

[0012] Preferably, each of the joints is distributed at two end positions of the diameter-reducing section along the axial direction of the diameter-reducing section.

[0013] Preferably, a positioning structure for positioning the ultrasonic transducer within the interface is provided between the interface and the ultrasonic transducer.

[0014] Preferably, the positioning structure includes an annular boss arranged on the inner wall of the interface, and the main body structure of the ultrasonic transducer is provided with an annular flange overlapping the annular boss, and a plug-fitting positioning groove and a positioning protrusion are provided between the annular boss and the annular flange.

[0015] Preferably, a sealing member is provided between the main body structure of the ultrasonic transducer and the inner peripheral wall of the interface, and the sealing member surrounds the outer peripheral side of the main body structure of the ultrasonic transducer.

[0016] Preferably, each of the connecting sections has a connecting flange at its end facing away from the reduced diameter section.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] By setting a reduced diameter section, the flow cross-section of the metering area can be reduced, and the flow velocity of the water is accelerated when the water flows through the reduced diameter section from the connecting section. Then, the interface is set in the reduced diameter section, and the ultrasonic transducer is installed at the corresponding position of the reduced diameter section, so that the ultrasonic waves emitted or received by the ultrasonic transceiver surface can pass through the accelerated water flow, thereby improving the measurement accuracy by increasing the water flow velocity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 It is a cross-sectional view of the overall structure in one embodiment of the present invention;

[0021] Figure 2 for Figure 1 A cross-sectional view from another perspective;

[0022] Figure 3 This is a diagram of the overall appearance structure of an embodiment of the present invention;

[0023] Figure 4 for Figure 3 Another perspective of the appearance structure diagram;

[0024] Among them, 1-connecting section, 2-reducing section, 3-connecting flange, 4-pressure cover, 5-ultrasonic transducer, 6-ultrasonic transmitting and receiving surface, 7-interface, and 8-notch structure. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0026] The purpose of the present invention is to provide a high-precision flow sensor for an ultrasonic water meter to solve the problems existing in the above-mentioned prior art and effectively improve the measurement accuracy.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figures 1 to 4As shown, this embodiment provides a high-precision ultrasonic water meter flow sensor, including a measuring tube and at least two pairs of ultrasonic transducers 5, the ultrasonic transducer 5 is made of a polymer material PPS alloy, the packaging thickness of the ultrasonic transducer 5 reaches more than 1.3mm, it is resistant to high temperatures above 130°C, resistant to strong acids and alkalis, strong rigidity, wear resistance and has good acoustic permeability; the driving voltage of the entire flow sensor is 3.2V, the operating power is 5μA, and the service life can reach 13 years by relying on battery drive, which makes up for the shortcomings of micro-power consumption sensors and can achieve micro-power consumption operation, and the entire ultrasonic transducer 5 is made into a packaging structure through an injection molding process, and the measuring tube is provided with two distributed along its flow direction. The connecting section 1 and the reduced diameter section 2 connected between the two connecting sections 1, the flow cross-section of the reduced diameter section 2 is smaller than that of the connecting section 1, and the radial cross-section of the connecting section 1 gradually decreases in the direction close to the reduced diameter section 2 to achieve the effect of buffering the water flow, and the reduced diameter section 2 is provided with interfaces 7 on both sides along its radial direction, and the two ultrasonic transducers 5 in each pair are respectively installed at the interfaces 7 on both sides of the measuring tube, and the ultrasonic transducer 5 is provided with an ultrasonic transmitting and receiving surface 6 extending into the measuring tube, and the side of the ultrasonic transducer 5 facing away from the measuring tube is blocked with a pressure cap 4, and the pressure cap 4 is detachably connected to the interface 7, and preferably the pressure cap 4 is threadedly connected to the interface 7 to press the side of the ultrasonic transducer 5 facing away from the reduced diameter section 2 to play a fixed blocking role. By setting the reduced diameter section 2, the flow cross-section of the metering area can be reduced, and the flow velocity of the water flow is accelerated when it passes through the reduced diameter section 2 from the connecting section 1. Then, the interface 7 is set in the reduced diameter section 2, and the ultrasonic transducer 5 is installed at the corresponding position of the reduced diameter section 2, so that the ultrasonic waves emitted or received by the ultrasonic transceiver surface 6 can pass through the accelerated water flow, thereby improving the measurement accuracy by increasing the water flow velocity.

[0029] Specifically, it should be noted that the ultrasonic speed measurement technology adopts the time difference method, and its speed measurement principle is:

[0030]

[0031] Among them, L is the ultrasonic stroke (effective distance measurement), c is the speed of sound, and v is the water flow velocity of the reduced diameter section 2. t is the time difference, which is the information data that can be directly measured by the electronic hardware. It can be seen from the above formula that its data can calculate the water flow velocity of the reduced diameter section 2. Under normal circumstances, at the minimum flow point of the water meter, t is a data at the level of hundreds of nanoseconds. Electronic components must have a certain degree of uncertainty, resulting in a fluctuation of ±1 nanosecond in the electronic measurement of t, and the uncertainty of the overall sampling data is about 1%; the purpose of the meter body design is to increase the data size level of t. The reduction in diameter on the measuring tube increases the water flow velocity of v in the reduced diameter section, which is conducive to the increase of t, thereby improving the measurement accuracy.

[0032] In this specific embodiment, the flow cross-sectional area of ​​the reduced diameter section 2 accounts for 40% to 80% of the flow cross-sectional area of ​​the connecting section 1 to fully ensure that the speed of water flowing through the reduced diameter section 2 is accelerated, and preferably the flow cross-sectional area of ​​the reduced diameter section 2 accounts for 50% to 60% of the flow cross-sectional area of ​​the connecting section 1.

[0033] In a specific implementation, the reduced diameter section 2 is a flat structure, and the interfaces 7 are distributed on both sides of the reduced diameter section 2 in the long side direction, so as to fully extend the effective distance measurement of the metering area, thereby effectively improving the measurement accuracy. Specifically, it should be noted that: Among them, D is the radial distance between the two ultrasonic transducers 5 in the same pair, that is, the distance along the radial direction of the measuring tube, and A is the axial distance between the two ultrasonic transducers 5, that is, the distance along the axial direction of the measuring tube. If the diameter reduction section is a circular diameter reduction, D becomes smaller, L becomes smaller, which is not conducive to the increase of t; and the diameter reduction section 2 is a flat structure, so that L, the ultrasonic stroke (effective ranging), does not decrease, and the interfaces 7 are distributed on both sides of the long side direction of the diameter reduction section 2, ensuring that A obtains the maximum value under the premise of the meter body length specified by the national standard. In summary, L obtains a larger size, and then the order of magnitude of t reaches twice that of an ordinary meter body, so that the uncertainty of the electronic timing chip measuring t at the minimum flow rate is reduced to about 0.5%, ensuring the measurement accuracy of the instrument at the minimum flow rate.

[0034] In a specific embodiment, the axis of the interface 7 is perpendicular to the axial direction of the reduced diameter section 2, and the ultrasonic transceiver surface 6 is distributed at an angle with the axis of the interface 7, so that the extension direction of the interface 7 and the gland 4 is perpendicular to the axial direction of the reduced diameter section 2, thereby avoiding positional interference with the connecting section 1 and other connecting pipes. Specifically, a notch structure 8 is provided at the position of the inner wall of the reduced diameter section 2 corresponding to the interface 7 to avoid the inner wall of the reduced diameter section 2 blocking the ultrasonic transceiver surface 6 and affecting the emission and reception of ultrasonic waves. Preferably, the ultrasonic transceiver surface 6 is distributed at an acute angle with the axis of the interface 7, so that the ultrasonic transceiver surfaces 6 of the two ultrasonic transducers 5 arranged in pairs can interact with each other. Further, the angle between the ultrasonic transceiver surface 6 and the axis of the interface 7 is within 20° to 70°, preferably within 35° to 55°, to avoid excessive inclination of the ultrasonic transceiver surface 6 and affecting the spacing between the two ultrasonic transceiver surfaces 6.

[0035] In a specific implementation, the joints are distributed at both ends of the diameter-reducing section 2 along the axial direction of the diameter-reducing section 2 to fully increase the effective distance measurement of the metering area, which can effectively improve the measurement accuracy.

[0036] In a specific embodiment, a positioning structure for positioning the ultrasonic transducer 5 in the interface 7 is provided between the interface 7 and the ultrasonic transducer 5, so that the ultrasonic transducer 5 can be self-positioned on the interface 7 during the installation process, thereby ensuring the convenience and effectiveness of the installation of the ultrasonic transducer 5. Preferably, the positioning structure includes an annular boss provided on the inner peripheral wall of the interface 7, an annular flange overlapped on the annular boss is provided on the body structure of the ultrasonic transducer 5, and a positioning groove and a positioning protrusion that are plug-fitted are provided between the annular boss and the annular flange, so that the stability of the installation of the ultrasonic transducer 5 is improved by plugging and fitting the positioning protrusion and the positioning groove.

[0037] In a specific embodiment, a seal is provided between the main structure of the ultrasonic transducer 5 and the inner circumferential wall of the interface 7 , and the seal surrounds the outer circumferential side of the main structure of the ultrasonic transducer 5 to improve the sealing between the ultrasonic transducer 5 and the interface 7 .

[0038] In a specific implementation, each connecting section 1 is provided with a connecting flange 3 at the end away from the reduced diameter section 2 , so as to complete the connection work between the entire measuring pipe and other pipelines through the connecting flange 3 .

[0039] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0040] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0041] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A high-precision ultrasonic water meter flow sensor, characterized in that: It comprises a measuring tube and at least two pairs of ultrasonic transducers, wherein the measuring tube is provided with two connecting sections distributed along its flow direction and a reduced diameter section connected between the two connecting sections, the flow cross-section of the reduced diameter section is smaller than that of the connecting section, and the reduced diameter section is provided with interfaces on both sides along its radial direction, the two ultrasonic transducers in each pair are respectively installed at the interfaces on both sides of the measuring tube, the ultrasonic transducers are provided with ultrasonic transmitting and receiving surfaces extending into the measuring tube, the side of the ultrasonic transducer facing away from the measuring tube is blocked with a pressure cover, and the pressure cover is detachably connected to the interface.

2. The high-precision ultrasonic water meter flow sensor according to claim 1, characterized in that: The flow cross-sectional area of ​​the reduced diameter section accounts for 40% to 80% of the flow cross-sectional area of ​​the connecting section.

3. The high-precision ultrasonic water meter flow sensor according to claim 1 or 2, characterized in that: The reduced diameter section is in a flat structure, and the interfaces are distributed on both sides of the reduced diameter section in the long side direction.

4. The high-precision ultrasonic water meter flow sensor according to claim 3, characterized in that: The axis of the interface is perpendicular to the axial direction of the reduced diameter section, and the ultrasonic transmitting and receiving surface is distributed at an angle to the axis of the interface.

5. The high-precision ultrasonic water meter flow sensor according to claim 4, characterized in that: The ultrasonic transmitting and receiving surface is distributed at an acute angle to the axis of the interface.

6. The high-precision ultrasonic water meter flow sensor according to claim 5, characterized in that: The joints are distributed at both ends of the diameter-reducing section along the axial direction of the diameter-reducing section.

7. The high-precision ultrasonic water meter flow sensor according to claim 6, characterized in that: A positioning structure for positioning the ultrasonic transducer within the interface is provided between the interface and the ultrasonic transducer.

8. The high-precision ultrasonic water meter flow sensor according to claim 7, characterized in that: The positioning structure includes an annular boss arranged on the inner peripheral wall of the interface, and the main body structure of the ultrasonic transducer is provided with an annular flange overlapped on the annular boss. A plug-fitting positioning groove and a positioning protrusion are provided between the annular boss and the annular flange.

9. The high-precision ultrasonic water meter flow sensor according to claim 8, characterized in that: A sealing member is provided between the main body structure of the ultrasonic transducer and the inner peripheral wall of the interface, and the sealing member surrounds the outer peripheral side of the main body structure of the ultrasonic transducer.

10. The high-precision ultrasonic water meter flow sensor according to claim 8, characterized in that: The end of each connecting section away from the reduced diameter section is provided with a connecting flange.

Images