Flow measurement device and system

Abstract

The utility model discloses a flow measuring device and system belongs to blood purification equipment technical field, including first ultrasonic detection subassembly, second ultrasonic detection subassembly and straight section's detection pipeline, first ultrasonic detection subassembly and second ultrasonic detection subassembly are respectively arranged in detection pipeline both ends face outside, the detection pipeline inner wall roughness is 0.2mu~1.6mu, and the working area ratio of first ultrasonic detection subassembly, second ultrasonic detection subassembly is 1.2~1.8 with pipeline inner hole area. The utility model discloses a flow measuring device, based on ultrasonic measurement, through the double optimization of pipeline structure and design parameter, the propagation path of ultrasonic wave is improved, the influence of interference signal is reduced, the probability that the bubble is attached to the inner wall of detection pipeline is reduced, the synchronous promotion of signal repeatability and signal to noise ratio is effectively brought, and the ultrasonic flowmeter measurement precision is improved.

Description

Technical Field

[0001] This utility model relates to the field of blood purification equipment technology, specifically a flow measurement device and system. Background Technology

[0002] In the field of medical device manufacturing, blood purification is a crucial therapeutic technology. Its core involves using specialized instruments and equipment to draw a patient's blood out of the body, remove metabolic waste or toxic substances through a specific procedure, and then reinfuse it into the body to maintain normal physiological functions. During this treatment, fluid balance control and accurate measurement of the patient's dehydration volume directly affect the effectiveness and safety of the treatment. These are core technological requirements for the research and application of blood purification equipment, thus placing extremely high demands on the accuracy, stability, and adaptability of related measurement technologies.

[0003] Currently, the technical solutions for achieving fluid balance and controlling the amount of dehydration in blood purification equipment are mainly divided into two categories: one is to use a weighing sensor to measure the weight of the treatment fluid to achieve fluid balance and control the amount of dehydration; the other is to use a flow meter to measure the flow rate of the detection pipeline and then integrate the flow rate over time to achieve fluid balance and control the amount of dehydration in the patient.

[0004] However, both existing technical solutions have significant drawbacks: The working principle of weighing sensor solutions is to convert the deformation of resistance strain gauges caused by external forces into electrical signals to achieve weight measurement. However, these sensors inherently suffer from large creep, slow dynamic response, and large nonlinear errors. Furthermore, their measurement accuracy is easily affected by environmental factors, leading to significant creep and measurement errors. Even with subsequent software algorithm optimization, these hardware defects cannot be fundamentally compensated for, making it difficult to accurately achieve fluid balance and control patient dehydration. More importantly, blood purification equipment using weighing sensors cannot function properly in complex environments such as bumps, swaying, and vibration, severely limiting its application scenarios.

[0005] For ultrasonic flow meter solutions, the core issues focus on signal stability and bubble interference. On one hand, in existing technologies, ultrasonic waves undergo multiple transmissions or superpositions of transmission and reflection during propagation, resulting in poor signal repeatability and a low signal-to-noise ratio, making effective measurement difficult, especially for low differential flow rates. On the other hand, existing measurement and detection pipelines are mostly made of PVC material. The surface of this material has an uneven structure at the microscale. These microscopic pits, scratches, or pores become ideal "nucleation points" for bubbles. Gas dissolved in the liquid preferentially precipitates at these defects to form initial bubbles. Under low flow rate conditions, the "dragging force" and "pressure difference resistance" of the fluid on the bubbles are insufficient to overcome the "adhesion" of the hydrophobic surface of the PVC material and the "anchoring effect" caused by the microscopic roughness, causing the bubbles to stably adhere to the pipe wall. This problem is particularly prominent on the inner wall of the detection pipeline and at sharp bends. Because the wavelength of high-frequency ultrasonic measurements is extremely short, strong scattering occurs when encountering bubbles with wavelengths comparable to the measured wavelength, directly leading to signal reception failure and severely affecting measurement accuracy.

[0006] In summary, the accuracy of liquid flow measurement and dehydration control in existing blood purification equipment is insufficient to meet the stringent requirements of clinical treatment. In particular, the measurement challenges in low-flow-rate scenarios have long remained unresolved. Therefore, there is an urgent need for a technical solution that can optimize measurement performance, improve accuracy and stability, in order to promote the upgrading and improvement of measurement technology in blood purification equipment. Utility Model Content

[0007] The purpose of this invention is to address the aforementioned shortcomings by providing a flow measurement device and system. Based on ultrasonic measurement, it reduces the influence of interference signals and decreases the probability of air bubbles adhering to the inner wall of the detection pipeline, effectively improving both signal repeatability and signal-to-noise ratio, thereby enhancing the measurement accuracy of the ultrasonic flow meter. To achieve the above objectives, this invention provides the following technical solution: A flow measurement device, characterized in that: it includes a first ultrasonic detection component, a second ultrasonic detection component, and a straight detection pipeline; the first ultrasonic detection component and the second ultrasonic detection component are respectively disposed on the outer sides of both end faces of the detection pipeline; the roughness of the inner wall of the detection pipeline is 0.2μm~1.6μm, and the ratio of the working area of ​​the first ultrasonic detection component and the second ultrasonic detection component to the inner bore area of ​​the pipeline is 1.2~1.8.

[0008] Furthermore, the inner diameter of the testing pipeline is 2.5mm~8mm, and the length is 36mm~135mm.

[0009] Furthermore, both the first ultrasonic testing component and the second ultrasonic testing component include a barrier block, an ultrasonic transceiver, a base, and a coupling block arranged sequentially; the coupling block is disposed between the base and the testing pipeline.

[0010] Furthermore, the surface roughness of the coupling block is 0.8μm~6.3μm.

[0011] Furthermore, the coupling block is made of rubber.

[0012] Furthermore, the thickness of the barrier block is 1.3mm to 5.5mm.

[0013] Furthermore, the detection pipeline is provided with an inlet pipe and an outlet pipe perpendicular to the detection pipeline at both ends, and the inlet pipe, detection pipeline and outlet pipe are distributed in a U-shape.

[0014] Furthermore, it also includes a housing; the housing has a positioning chamber inside that is adapted to the first ultrasonic detection component, the second ultrasonic detection component and the detection pipeline, for positioning each component.

[0015] Furthermore, the housing is provided with through clearance holes corresponding to the positions of the inlet and outlet pipes; the diameter of the clearance holes is adapted to the size of the inlet and outlet pipes, which facilitates the connection of the inlet and outlet pipes to external pipelines.

[0016] Furthermore, it includes a controller, a data transmission module, a host computer, and the aforementioned flow measurement device; the controller is electrically connected to the first ultrasonic detection component and the second ultrasonic detection component; the data transmission module is electrically connected to both the controller and the host computer, and is used to transmit flow measurement data; the host computer is used for data storage, display, and analysis.

[0017] The beneficial effects of this utility model are: This utility model discloses a flow measurement device and system, including a first ultrasonic detection component, a second ultrasonic detection component, and a detection pipeline; the first and second ultrasonic detection components are symmetrically arranged on both sides of the detection pipeline and are both electrically connected to a controller; the controller calculates the fluid flow rate based on the ultrasonic propagation time difference; the roughness of the inner wall of the detection pipeline is 0.2μm~1.6μm, and the ratio of the working area of ​​the first and second ultrasonic detection components to the inner hole area of ​​the pipeline is 1.2~1.8. This utility model discloses a flow measurement device based on ultrasonic measurement. Through dual optimization of pipeline structure and design parameters, the propagation path of ultrasonic waves is improved, and the influence of interference signals is reduced. In particular, research has verified that the adhesion of bubbles is worst when the roughness of the inner wall of the pipeline is in the range of 0.2μm to 1.6μm. The setting of this application reduces the probability of bubbles adhering to the inner wall of the detection pipeline. The setting of the ratio of the working area of ​​the detection component to the inner hole area of ​​the detection pipeline comprehensively considers the output sound power, penetration and sensitivity, effectively bringing about a simultaneous improvement in signal repeatability and signal-to-noise ratio, improving the measurement accuracy of ultrasonic flow meters, and making low-speed flow measurement possible. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural schematic diagram of the flow measurement device of this utility model; Figure 2 This is a schematic diagram of the planar structure of the flow measurement device of this utility model; In the attached diagram: 1-Controller, 2-Housing, 3-Barrier block, 41-First ultrasonic detection component, 42-Second ultrasonic detection component, 4-Ultrasonic transceiver, 5-Coupled block, 6-Detection pipeline, 7-Base, 8-Inlet pipe, 9-Outlet pipe. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0020] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0021] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0022] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. The meaning of such spatial relative terms includes different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, then an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0023] Example 1: See attached Figure 1 This utility model discloses a flow measurement device comprising a first ultrasonic detection component 41, a second ultrasonic detection component 42, a straight detection pipe 6, and a housing 2. The straight section refers to the straight inner diameter of the detection pipe 6, which ensures that the liquid flow direction within the detection pipe 6 is consistent with or parallel to the ultrasonic waves emitted by the first and second ultrasonic detection components 41 and 42, maximizing detection accuracy. The housing 2 has a receiving cavity, within which the first ultrasonic detection component 41, second ultrasonic detection component 42, and detection pipe 6 are installed. The components are stably connected through precise assembly, and the housing 2 protects each component. An inlet pipe 8 and an outlet pipe 9, perpendicular to the detection pipe 6, are respectively provided at both ends of the detection pipe 6. The inlet pipe 8, detection pipe 6, and outlet pipe 9 are distributed in a U-shape. A through-hole is provided on the housing 2 at the position corresponding to the inlet pipe 8 and outlet pipe 9. The diameter of the through-hole is adapted to the size of the inlet pipe 8 and outlet pipe 9 to ensure that the inlet pipe 8 and outlet pipe 9 can pass through smoothly without affecting the connection between the inlet pipe 8 and outlet pipe 9 and the external pipeline. The first ultrasonic detection component 41 and the second ultrasonic detection component 42 have a symmetrical structure and are respectively installed on the outer side of the two end faces of the detection pipe 6. Based on the time difference of the ultrasonic signals received by the first ultrasonic detection component 41 and the second ultrasonic detection component 42, and combined with the flow channel geometric parameters and physical model, the real-time flow velocity and instantaneous flow rate are calculated. Among them, the detection pipe 6 adopts an integrated straight pipe structure. Since the smoothness of the inner wall of the detection pipe 6 affects the adhesion of bubbles, the higher the smoothness of the inner wall of the detection pipe 6, the less conducive it is to bubble adhesion; the lower the smoothness, the easier it is for bubbles to adhere and remain. Testing and verification showed that bubble adhesion was worst when the inner wall roughness of the detection pipe 6 was within the range of 0.2μm to 1.6μm. Therefore, the inner wall of the detection pipe 6 of this flow measurement device undergoes precision machining, such as... Figure 2The inner wall roughness of the detection pipe 6 shown is Ra´, ensuring that the roughness Ra´ is within the range of 0.2μm~1.6μm. Furthermore, when ultrasound propagates in a fluid, its energy is absorbed and scattered by the fluid. The higher the frequency, the stronger this absorption and scattering effect, and the faster the signal attenuates. When the diameter of the detection pipe 6 is smaller, the corresponding ultrasonic crystal area is smaller, and the beam spread angle is inversely proportional to the crystal diameter. Sound waves generated by a small-sized crystal are easier to concentrate into a point sound source, with a shorter near-field region and a larger far-field beam spread angle. However, in some high-frequency applications, a small crystal helps to obtain a smaller effective detection point, thereby improving lateral resolution. However, when the diameter of the detection pipe 6 is smaller, the emission area is smaller, and the volume of the propelling medium is also smaller, resulting in limited output acoustic energy, weak penetration, and excessively weak echo signals. When the diameter of the detection pipe 6 is larger, the corresponding ultrasonic crystal area is larger, resulting in higher output acoustic power and sensitivity, and a longer far-field propagation distance. However, as the diameter of the detection pipe 6 increases, the larger the sound source size leads to a longer near-field region. This results in uneven sound pressure distribution within the near-field region, with multiple maxima and minima, interfering with the interpretation of the echo signal and thus reducing the lateral resolution of the near-field. Testing has verified that the inner diameter of the detection pipe 6 is controlled between 2.5mm and 8mm, and the liquid path length is between 36mm and 135mm. This size range optimizes the propagation path of the ultrasonic wave in the fluid, reduces signal attenuation, and simultaneously ensures the stability of the fluid flow, providing structural support for low-flow-rate measurements. Therefore, as... Figure 2 The inner diameter of the detection pipe 6 shown is D, and the liquid path length is L1. The inner diameter of the detection pipe 6 of this flow measurement device is in the range of 2.5mm to 8mm, and the liquid path length L1 is in the range of 36mm to 135mm.

[0024] Specifically, both the first ultrasonic detection assembly 41 and the second ultrasonic detection assembly 42 include a blocking block 3, an ultrasonic transceiver 4, a base 7, and a coupling block 5 arranged sequentially. Bases 7 are provided on the outer sides of both ends of the detection pipeline 6, and the ultrasonic transceivers 4 are respectively installed inside the bases 7, symmetrically about the center of the detection pipeline 6. A blocking block 3 is also provided inside the base 7, located on the side of the ultrasonic transceiver 4 away from the detection pipeline 6, used to absorb back-facing sound waves and suppress vibration interference. A coupling block 5 is sandwiched between the base 7 and the detection pipeline 6 for coupling and stable transmission of ultrasonic signals. The coupling block 5 can also be adapted to clamp both ends of the detection pipeline 6, so the detection pipeline 6 can be disposable, removed after use, and replaced with a new one for the next use. Of course, the detection pipeline 6 can also be used long-term. Since different sizes of detection pipe 6 correspond to different working areas of ultrasonic transceiver 4, they collectively affect the propagation of ultrasonic waves in the fluid. Through testing and verification, when the inner diameter of the detection pipe 6 is determined, the ratio of the working area of ​​the ultrasonic transceiver 4 (the cross-sectional area of ​​the ultrasonic transceiver 4's ultrasonic wave transmission and reception area) to the cross-sectional area of ​​the inner diameter of the detection pipe 6 is in the range of 1.2 to 1.8. Figure 2 The cross-sectional area of ​​the inner hole of the detection pipe 6 shown is S1, and the working area of ​​the ultrasonic transceiver 4 is S2. The ratio of S2 / S1 is in the range of 1.2 to 1.8, which can balance the diffusion and penetration capabilities of the sound beam and improve the sensitivity of signal reception. The coupling block 5 is made of rubber. For the same coupling block 5, the higher the surface roughness of the workpiece, the worse the coupling effect and the lower the reflected echo, especially for coupling materials with low acoustic impedance. However, lower roughness is not always better, as excessively low roughness can increase the adhesion between the probe and the workpiece. Testing has verified that when the surface roughness of the coupling block 5 is between 0.8 μm and 6.3 μm, the coupling effect is optimal, reducing energy loss of the ultrasonic wave during propagation. Figure 2As shown, the surface roughness of the coupling block 5 in this invention is Ra, with a value ranging from 0.8 μm to 6.3 μm. Furthermore, the thickness of the blocking block 3 also affects the propagation of ultrasonic waves. A thicker blocking block 3 more effectively absorbs a wider range of back-facing sound waves, significantly reducing unnecessary vibrations and ringing, which is even more effective for wafers with a high proportion of broadband or low-frequency components. However, a thicker blocking block 3 leads to a decrease in the overall vibration efficiency of the wafer, resulting in a significant reduction in both transmission power and receiving sensitivity, making the probe "insensitive." Conversely, a thinner blocking block 3 emits stronger acoustic energy and has a better ability to receive weak echoes, making the probe very "sensitive." However, a thinner blocking block 3 results in a longer pulse duration (ringing phenomenon), severely reducing axial resolution. This manifests as a trailing effect in the image, making it difficult to distinguish between two closely spaced targets during detection. Exciting or receiving broadband signals limits the ability to detect details. The effective signal-to-noise ratio may even decrease, especially when detecting defects behind or near the surface of shallow targets. Testing has verified that the thickness of the blocking block 3, ranging from 1.3mm to 5.5mm, effectively absorbs the backsound waves generated by the ultrasonic transceiver 4 during operation, suppressing vibration interference and ringing, and ensuring the stability of the ultrasonic signal. Figure 2 As shown, the thickness of the barrier block 3 of this utility model is h1, and the value of h1 is in the range of 1.3mm to 5.5mm.

[0025] Example 2: The flow measurement system of this utility model includes a controller 1, a data transmission module, a host computer, and the aforementioned flow measurement device. The controller 1 is electrically connected to the first ultrasonic detection component 41 and the second ultrasonic detection component 42. The data transmission module is electrically connected to the controller 1 of the flow measurement device. The core function of the data transmission module is to transmit the measurement data such as flow velocity, instantaneous flow rate, and cumulative flow rate calculated by the controller 1 to the host computer in real time. Simultaneously, it can also feed back control commands from the host computer to the controller 1, achieving bidirectional data interaction. After establishing a communication connection with the data transmission module, the host computer can receive and store all measurement data sent by the transmission module. Furthermore, the host computer has a data export function, which can export the stored measurement data in the form of tables, curves, etc., providing data support for subsequent data analysis, equipment debugging, or treatment effect evaluation. Other components of the flow measurement system are well known to those skilled in the art; therefore, they will not be described in detail here.

[0026] The working principle of this flow measurement device for measuring average flow velocity is as follows: This flow measurement device uses the time-of-flight method. In a fluid, ultrasonic waves travel faster in the direction of flow and slower against the flow. By accurately measuring the time difference between the upstream and downstream propagation of the ultrasonic waves, the average flow velocity of the fluid can be calculated.

[0027] One side of the ultrasonic transceiver device 4 acts as a transmitter, emitting a beam of ultrasonic pulse into the fluid. The ultrasonic pulse propagates along the flow direction of the fluid, and is received by the opposite ultrasonic transceiver device 4 on the other side after a period of time t1; immediately after (or after a short delay), the ultrasonic transceiver device 4 that received the signal last time acts as a transmitter, emitting a beam of ultrasonic pulse into the fluid. This beam of ultrasonic pulse propagates against the flow direction of the fluid, and is received by the ultrasonic transceiver device 4 that emitted the signal last time after a period of time t2. The controller accurately measures these two times t1 and t2.

[0028] The inner hole diameter of the detection pipeline is D, the included angle between the ultrasonic propagation path and the detection pipeline is θ, in this utility model, this included angle θ is 0°, the sound velocity when the fluid is stationary is c, and the average flow velocity of the fluid is v.

[0029] Downstream propagation time: t1=L / (c+v); Upstream propagation time: t2=L / (c-v); Wherein L is the straight-line distance between the first ultrasonic transceiver device and the second ultrasonic transceiver device.

[0030] Calculate the time difference: Δt=t2-t1=(2Lv) / (c 2 -v 2 ); Since in most cases, the flow velocity v of the fluid is much smaller than the sound velocity c (i.e. v<<c), the formula can be simplified as: Δt≈(2Lv) / c²; From this, the flow velocity can be derived as: v≈(c²Δt) / (2Lcosθ); It can be seen from the formula that as long as the time difference Δt is measured, and combined with the known c (sound velocity), L and θ, the average flow velocity v of the fluid can be calculated. Multiply it by the cross-sectional area of the detection pipeline to obtain the volume flow rate.

[0031] All the technical features in this embodiment can be freely combined according to actual needs. The above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the utility model without departing from the spirit and scope of the technical solution of the utility model, all of which shall be covered within the scope of the claims of the utility model. The parts of the utility model that are not described in detail in terms of technology, shape and structure are all well-known technologies.

[0032] The above embodiments are preferred implementations of this utility model. In addition, other implementations are also included. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.

Claims

1. A flow measurement device, characterized in that: It includes a first ultrasonic testing component (41), a second ultrasonic testing component (42), and a straight section of testing pipeline (6); the first ultrasonic testing component (41) and the second ultrasonic testing component (42) are respectively disposed on the outer side of both ends of the testing pipeline (6); the inner wall roughness of the testing pipeline (6) is 0.2μm~1.6μm, and the ratio of the working area of ​​the first ultrasonic testing component (41) and the second ultrasonic testing component (42) to the inner hole area of ​​the pipeline is 1.2~1.

8.

2. The flow measurement device according to claim 1, characterized in that: The inner diameter of the testing pipeline (6) is 2.5mm~8mm, and the length is 36mm~135mm.

3. A flow measurement device according to claim 1 or 2, characterized in that: The first ultrasonic detection component (41) and the second ultrasonic detection component (42) each include a barrier block (3), an ultrasonic transceiver device (4), a base (7) and a coupling block (5) arranged in sequence; the coupling block (5) is arranged between the base (7) and the detection pipeline (6).

4. A flow measurement device according to claim 3, characterized in that: The surface roughness of the coupling block (5) is 0.8μm~6.3μm.

5. A flow measurement device according to claim 3, characterized in that: The coupling block (5) is made of rubber.

6. A flow measurement device according to claim 3, characterized in that: The thickness of the barrier block (3) is 1.3mm to 5.5mm.

7. A flow measurement device according to any one of claims 1, 2, or 4-6, characterized in that: The detection pipeline (6) has an inlet pipe (8) and an outlet pipe (9) perpendicular to the detection pipeline (6) at both ends, and the inlet pipe (8), the detection pipeline (6) and the outlet pipe (9) are distributed in a U-shape.

8. A flow measurement device according to claim 7, characterized in that: It also includes a housing (2); the housing (2) has a positioning chamber inside that is adapted to the first ultrasonic detection component (41), the second ultrasonic detection component (42) and the detection pipeline (6) for positioning each component.

9. A flow measurement device according to claim 8, characterized in that: The housing (2) is provided with through clearance holes corresponding to the positions of the inlet pipe (8) and the outlet pipe (9); the diameter of the clearance holes is adapted to the size of the inlet pipe (8) and the outlet pipe (9) to facilitate the connection of the inlet pipe (8) and the outlet pipe (9) with external pipelines.

10. A flow measurement system, characterized in that: It includes a controller (1), a data transmission module, a host computer, and a flow measurement device as described in any one of claims 1 to 9; the controller (1) is electrically connected to the first ultrasonic detection component (41) and the second ultrasonic detection component (42), and the data transmission module is electrically connected to the controller (1) and the host computer respectively, for transmitting flow measurement data; the host computer is used for data storage, display and analysis.

Images