A turbine flowmeter

Abstract

The utility model relates to the technical field of miniaturization flowmeter, concretely relates to a turbine flowmeter, including setting up in the inside pipe measuring tube, the inside measuring tube is provided with turbine body, the outer wall of pipeline is provided with the detection device for detecting turbine body rotating speed, the detection device includes the installation groove setting up on the pipeline, the inside installation groove is provided with hall sensor, the turbine body includes the impeller, the water -facing surface of impeller is provided with two helical surfaces, can satisfy the stable accurate measurement under the specific working environment, has guaranteed use effect.

Description

Technical Field

[0001] This utility model relates to the field of miniaturized flow meter technology, specifically to a turbine flow meter. Background Technology

[0002] A turbine flow meter is a velocity-type flow meter that utilizes the proportional relationship between the rotational angular velocity of an impeller placed in the fluid and the fluid velocity. It reflects the volumetric flow rate through the pipe by measuring the impeller's rotational speed. However, under specific working conditions, such as when the working medium is deionized water, the working pressure is ≤2.0MPa, and the working temperature is ≤60℃, and the fluid flows from bottom to top when vertically installed; the measuring range is (1.5~15)m. 3 The flow meter needs to achieve an accuracy of 0.5 during operation and also requires the acquisition and detection of its operating signal. Existing methods for signal acquisition mostly use coils, but this is impossible under these conditions due to the large size of coils (typically 8-10 mm in diameter and 10-15 mm in length), the need for sealing (making it unsuitable in a space with a maximum wall thickness of 8.5 mm), and the requirement of operating in water at 2.0 MPa and 60°C (a much higher pressure than conventional turbine flow meters, whose highest IP68 rating only requires 0.15 MPa). Furthermore, the smaller size of conventional impellers necessitates extremely high rotational speeds, leading to errors in impeller data measurement and reduced accuracy. Therefore, a new turbine flow meter is needed to ensure stable and accurate operation under these conditions. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies in the unstable operation and inaccurate detection results of miniaturized turbine flow meters, and to provide a turbine flow meter.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a turbine flow meter, comprising a measuring tube disposed inside a pipe, a turbine body disposed inside the measuring tube, a detection device for detecting the rotational speed of the turbine body disposed on the outer wall of the pipe, the detection device comprising an installation groove disposed on the pipe, a Hall sensor disposed inside the installation groove, the turbine body comprising an impeller, and the water-facing surface of the impeller comprising two helical surfaces.

[0005] Furthermore, the mounting groove is provided along the length of the pipe, the Hall sensor is disposed inside the sealing tube, the end of the mounting groove is provided with a fixing hole for connection with the sealing tube, and the side of the sealing tube is provided with a receiving groove.

[0006] Furthermore, the inside of the pipe is provided with a positioning groove for accommodating the measuring tube, the end of the measuring tube is provided with a connector, the outside of the connector is provided with a thread for screwing into the inner wall of the pipe, and the inside of the connector is provided with a snap-fit ​​groove for disassembly.

[0007] Furthermore, the measuring tube is provided with a flow guide for fixing the vortex body. The flow guide is provided in two sets, which are respectively set at both ends of the measuring tube. The connector is pressed into the measuring tube.

[0008] Furthermore, the flow guide includes a tapered flow guide head, and the side of the flow guide head is provided with a snap-fit ​​plate that connects to the measuring tube.

[0009] Furthermore, the bottoms of the two guide heads are arranged opposite each other, and the bottom of each guide head is provided with a frustum-shaped connecting seat, and the impeller is arranged between the two guide heads.

[0010] Furthermore, the impeller includes a connecting shaft located in the middle, a rotor is disposed on the outer side of the connecting shaft, and a magnet is disposed on the outer surface of the rotor.

[0011] Furthermore, the magnet is positioned at the junction between the two helical surfaces.

[0012] The beneficial effects of this utility model embodiment are as follows: the turbine body is set inside the measuring tube, which facilitates the overall installation and replacement. The installation position of the turbine body corresponds to the position of the Hall sensor, which facilitates the detection and collection of signals. Two helical surfaces are provided on the water-facing side. In this technical solution, due to its small size and installation inside the pipe, the two helical surfaces can effectively change the flow state of the fluid. Compared with the impeller with a single helical surface in the prior art, the design of two helical surfaces makes the flow of fluid on the impeller surface more uniform and stable, reduces the pressure fluctuation of the fluid on the impeller surface, reduces the probability of low-pressure area generation, extends the service life of the impeller, and improves the accuracy of the detection results. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0015] Figure 3 This is a schematic diagram of the measuring tube and sealing tube of this utility model;

[0016] Figure 4 This is a schematic diagram of the internal structure of the measuring tube of this utility model;

[0017] Figure 5 This is a schematic diagram of the overall structure of the impeller of this utility model;

[0018] Figure 6 This is a schematic diagram of the working condition feedback of this utility model;

[0019] In the diagram: 1. Pipe; 101. Mounting groove; 2. Sealing pipe; 201. Hall sensor; 3. Measuring tube; 301. Connector; 302. Snap-fit ​​groove; 4. Snap-fit ​​plate; 5. Flow guide head; 501. Connecting shaft; 6. Impeller; 601. Magnet. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely for explaining the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] See Figures 1 to 6 This utility model discloses a turbine flow meter that, under specific working conditions, such as working medium being deionized water, working pressure not exceeding 2.0 MPa, working temperature not exceeding 60°C, and vertical installation (fluid flowing from bottom to top), has a measuring range of (1.5~15) m. 3 In scenarios requiring a flow rate of / h and an accuracy of 0.5, while also needing to acquire and detect the flow meter's operating signal, conventional turbine flow meters have several insurmountable drawbacks. For example, conventional coil detection methods cannot be installed in spaces with a maximum wall thickness of 8.5mm due to the large size of the coil; furthermore, the maximum pressure requirement of a conventional turbine flow meter's IP68 rating is only 0.15MPa, which is insufficient to meet the 2.0MPa operating pressure in this situation; additionally, if a conventional impeller 6 is used for detection, it must maintain an extremely high speed to meet the range requirements, which easily leads to damage, reducing the impeller 6's service life and affecting the accuracy of the detection results.

[0022] The system mainly includes a measuring tube 3 installed inside pipe 1, with a turbine body inside the measuring tube 3. A detection device for detecting the turbine body's rotational speed is installed on the outer wall of pipe 1. The detection device includes a mounting groove 101 installed on pipe 1, extending along the length of pipe 1. A Hall sensor 201 is installed inside the mounting groove 101, which is located inside a sealed tube 2. A fixing hole is provided at the end of the mounting groove 101 for connection to the sealed tube 2. This fixing hole securely mounts the sealed tube 2 within the mounting groove 101 and fixes the position of the Hall sensor 201, improving detection accuracy. A receiving groove is provided inside the mounting groove 101 next to the sealed tube 2 to accommodate related wiring and provide space for hand or tool clamping. The detection method using the Hall sensor 201 has significant advantages over traditional coil detection methods. The Hall sensor 201 is compact and can be easily installed in spaces with a maximum wall thickness of 8.5mm, solving the problem of traditional coils being too large to install. Meanwhile, the Hall sensor 201, sealed by the sealing tube 2, can operate stably in a water environment of 2.0 MPa and 60℃, meeting the usage requirements of this specific working environment.

[0023] To facilitate installation within a limited space, the turbine body is entirely housed inside the measuring tube 3, allowing for easy installation and replacement. The turbine body's installation position corresponds to that of the Hall sensor 201, facilitating signal detection and collection. The impeller 6 within the turbine body features a unique design with two helical surfaces on its water-facing side. In this technical solution, due to its small size and installation inside the pipe 1, two impellers 6 are used, each with a certain thickness. The helical surface at the front end of the impeller 6 has a slightly smaller area, reducing resistance when breaking the water flow. Furthermore, during fluid flow, when the fluid impacts the impeller 6, these two helical surfaces effectively alter the fluid's flow state. Compared to the single-helical-surface impeller 6 in existing technologies, the two-helical-surface design results in more uniform and stable fluid flow on the impeller 6 surface. In a single-helical-surface impeller 6, localized turbulence and eddies are easily generated after the fluid impacts the impeller 6, leading to uneven force distribution on the impeller 6. This not only increases wear on the impeller 6 but also affects its rotational speed stability, thereby impacting the accuracy of flow detection. The dual helical surface design allows the fluid to form a more regular flow trajectory on the surface of impeller 6, reducing the generation of turbulence and eddies, making the force on impeller 6 more uniform, and making the impeller 6 rotate more smoothly, which makes it easier to achieve higher speeds. In order to improve the durability of impeller 6 at high speeds, impeller 6 is made of titanium, extending its service life and ensuring its performance.

[0024] Meanwhile, the design of two helical surfaces reduces the possibility of damage to the impeller 6. In existing technologies, because the impeller 6 needs to maintain an extremely high rotational speed to meet the measurement range requirements, low-pressure areas are easily generated on the surface of the impeller 6 when there are large changes in fluid pressure and flow velocity. This affects the rotational stability of the impeller 6 and reduces the accuracy of the test results. However, the two helical surface design in this technical solution optimizes the fluid flow state, reduces pressure fluctuations on the surface of the impeller 6, reduces the probability of low-pressure areas, extends the service life of the impeller 6, and improves the accuracy of the test results.

[0025] The impeller 6 also includes a connecting shaft 501 located in the middle. A rotor is mounted on the outer side of the connecting shaft 501, and the impeller 6 is mounted on the side of the rotor. A magnet 601 is mounted on the outer end face of the impeller 6, and the magnet 601 is located at the junction between the two helical surfaces. When the impeller 6 rotates, the magnet 601 rotates accordingly. The Hall sensor 201 can sense the change in the magnetic field of the magnet 601, thereby converting the rotational speed signal of the impeller 6 into an electrical signal for acquisition and detection. This makes the signal detection more accurate and reliable, and can reflect the volumetric flow rate through the pipe 1 in a timely and accurate manner, ensuring the accuracy of the detection results.

[0026] The pipe 1 has a positioning groove inside to accommodate the measuring tube 3. The positioning groove is set on the inner wall of the pipe 1 to form a step for positioning the measuring tube 3 and ensuring the accuracy of the installation position. The end of the measuring tube 3 is provided with a connector 301. The outside of the connector 301 is provided with a thread that screws into the inner wall of the pipe 1. The threaded connection allows the measuring tube 3 to be easily installed inside the pipe 1 and ensures the stability of the installation. The inside of the connector 301 is provided with a snap-fit ​​groove 302 for disassembly. When it is necessary to repair or replace the turbine body, the measuring tube 3 can be easily removed from the pipe 1 through the snap-fit ​​groove 302. The connector 301, by screwing into the inside of the pipe 1, presses the measuring tube 3 tightly inside the pipe 1 to ensure the stability of the installation. The measuring tube 3 is provided with a flow guide for fixing the turbine body. There are two sets of flow guides, which are respectively set at both ends of the measuring tube 3. The flow guide includes a conical flow guide head 5, with a snap-fit ​​plate 4 on the side of the flow guide head 5 that connects to the measuring tube 3. The snap-fit ​​plate 4 securely mounts the flow guide head 5 inside the measuring tube 3. The bottoms of the two flow guide heads 5 are positioned opposite each other, and each flow guide head 5 has a frustum-shaped connecting seat at its bottom. The impeller 6 is positioned between the two flow guide heads 5. The design of the flow guide can guide and rectify the fluid, directing the water flow onto the impeller 6, allowing the fluid to impact the impeller 6 more smoothly, further improving the stability of the impeller 6's rotation and the accuracy of flow detection. The connector 301 is crimped into the measuring tube 3. This connection method is simple and reliable, ensuring the sealing and stability of the internal structure of the measuring tube 3. By employing a Hall sensor 201 detection device and a unique design with a double-helix impeller 6, along with a reasonable structural arrangement of the measuring tube 3 and flow guide components, the flowmeter can achieve stable, accurate, and reliable operation under specific working conditions, extending its service life and ensuring optimal performance. The impeller 6 features a double-helix structure, an O-ring seal, and a Hall sensor 201 for signal detection, adapting to special environments while achieving a wide linear range. During the experiment, the flowmeter's calibration standards were as follows:

[0027] (1) The calibration of the flow meter should include the following flow points: q min q t 0.4q max and q max For flow meters with an accuracy class better than 0.5% and LWTY type turbine flow meters, increase by 0.25q. max and 0.7q max Two flow points; for flow meters with an accuracy class better than 0.5% and a range ratio greater than 20:1, add an additional calibration point with a flow rate of 0.1q. max .

[0028] (2) During the calibration process, each flow point should be adjusted only after the pressure, temperature, and flow rate have stabilized before calibration can be performed.

[0029] (3) During the verification process, the deviation between the actual verification flow rate and the set flow rate at each flow point should not exceed ±5%.

[0030] (4) Each flow point should be calibrated at least 3 times, and for flow meters with an accuracy class better than 0.5, each flow point should be calibrated at least 6 times.

[0031] The specific operating method is as follows:

[0032] (1) Adjust the flow rate to the specified flow rate value. After stabilization, start the device (or the recording function of the device) and the flow meter to be calibrated (or the output function of the flow meter to be calibrated).

[0033] (2) Record the initial readings of the standard device and the flow meter under test. After running the device for a period of time according to the device operation requirements, stop the device (or the recording function of the device) and the flow meter under test (or the output function of the flow meter under test) at the same time.

[0034] (3) Record the final readings of the recording device and the flow meter being calibrated.

[0035] (4) Calculate the cumulative flow or instantaneous flow recorded by the flow meter and the device respectively.

[0036] And the error is calculated based on the collected data:

[0037] (1) Calculate the indication error using the instrument coefficient K

[0038] Calculate the instrument coefficient K for each calibration according to formula (1). ij :

[0039]

[0040] Where: K ij —The instrument coefficient for the j-th calibration at the i-th calibration point, (m 3 ) -1 or L -1 ;

[0041] N ij —The number of pulses obtained by the flow meter display instrument side during the j-th calibration at the j-th calibration point;

[0042] V ij —The actual volume measured by the device at the j-th calibration point of the i-th calibration point, in m 3 Or L;

[0043] i—1, 2, ..., m, where m is the number of check points, and m≥3;

[0044] j—1, 2, ..., n, where n is the number of checks, and n≥3.

[0045] Calculate the average instrument coefficient K at each calibration point according to formula (2). i :

[0046]

[0047] Where: K i —The average instrument coefficient at the calibration points, (m 3 ) -1 or L -1 ;

[0048] n — the number of times each traffic verification point is checked.

[0049] Calculate the meter coefficient K of the flow meter according to formula (3):

[0050]

[0051] Where: K—the meter coefficient of the flow meter, (m 3 ) -1 or L -1 ;

[0052] (K i ) max —Flow meter at q i to q max The median maximum value obtained from each flow verification point within the flow range, (m) 3 ) -1 or L -1 ;

[0053] (K i ) min —Flow meter at q i to q max The minimum value obtained from each flow verification point within the flow range, (m) 3 ) -1 or L -1 ; .

[0054] Calculate the maximum indication error E of the flow meter according to formula (4):

[0055]

[0056] (2) Calculate the indication error using cumulative flow.

[0057] Calculate the relative indication error of the flow meter using equations (5) and (6):

[0058]

[0059] In the formula: E ij —The indication error of the flowmeter at the j-th calibration point of the i-th calibration point;

[0060] V ij—The cumulative flow rate displayed by the flow meter at the j-th calibration point, m 3 Or L;

[0061] (V e ) ij —The cumulative flow value calculated at the flow meter during the j-th calibration at the i-th calibration point, m 3 Or L. The relative indication error of the flowmeter under test at the l-th calibration point is calculated according to formula (6).

[0062]

[0063] And perform repetitive calculations:

[0064] Calculation of flow meter repeatability:

[0065]

[0066] Flowmeter repeatability:

[0067]

[0068] The following experimental data was obtained after the above data collection, calculation, and comparison:

[0069] The single-helix impeller calibration record is as follows:

[0070]

[0071] The calibration record for the double helix impeller is as follows:

[0072]

[0073] Based on the above data, it can be seen that the double-helix impeller in this technical solution has higher stability compared with the existing single-helix impeller. In the environment of a flow meter used to measure water flow in a nuclear power research and testing device, it is not only adapted to the special environment, but also achieves a wider linear range.

[0074] It should be noted that in the description of this utility model, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0075] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0076] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0077] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A turbine flow meter, comprising a measuring tube disposed inside a pipe, characterized in that: The measuring tube contains a turbine body, and the outer wall of the pipe is provided with a detection device for detecting the rotational speed of the turbine body. The detection device includes a mounting groove on the pipe, and a Hall sensor is installed inside the mounting groove. The turbine body includes an impeller, and the water-facing surface of the impeller has two helical surfaces.

2. The turbine flow meter according to claim 1, characterized in that: The mounting groove is provided along the length of the pipe, the Hall sensor is installed inside the sealing tube, the end of the mounting groove is provided with a fixing hole for connecting to the sealing tube, and the side of the sealing tube is provided with a receiving groove.

3. The turbine flow meter according to claim 1, characterized in that: The pipe has a positioning groove inside for accommodating the measuring tube, and the end of the measuring tube has a connector. The connector has threads on the outside that are screwed into the inner wall of the pipe, and the connector has a snap-fit ​​groove inside for disassembly.

4. The turbine flow meter according to claim 3, characterized in that: The measuring tube is equipped with a flow guide for fixing the vortex body. There are two sets of flow guides, which are respectively set at both ends of the measuring tube. The connector is pressed into the measuring tube.

5. The turbine flow meter according to claim 4, characterized in that: The flow guide includes a tapered flow guide head, and a snap-fit ​​plate connected to the measuring tube is provided on the side of the flow guide head.

6. The turbine flow meter according to claim 5, characterized in that: The bottoms of the two guide heads are arranged opposite each other, and the bottom of each guide head is provided with a frustum-shaped connecting seat. The impeller is arranged between the two guide heads.

7. The turbine flow meter according to claim 1, characterized in that: The impeller includes a connecting shaft located in the middle, a rotor located on the outer side of the connecting shaft, and a magnet located on the outer surface of the rotor.

8. The turbine flow meter according to claim 7, characterized in that: The magnet is positioned at the junction between the two helical surfaces.

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