Rectification pressure tapping assembly and honeycomb flowmeter

Abstract

The utility model relates to the technical field of fluid measurement, in particular to a rectification pressure tapping assembly and a honeycomb flowmeter. Comprising a differential pressure measuring tube, tube bundles, a first damping net and a second damping net, at least two through holes are formed in the side surface of the differential pressure measuring tube and serve as a high-pressure tapping port and a low-pressure tapping port respectively, and the tube bundles are gathered according to a preset array rule and installed in the differential pressure measuring tube. The pipeline direction of the tube bundle is the same as that of the pressure difference measuring tube, the first damping net is installed at the front end of the tube bundle, the second damping net is installed at the tail end of the tube bundle, and the first damping net and the second damping net are located between the two pressure tapping ports. Compared with traditional pressure difference acquisition and measurement, the flow separation range is narrowed, the flow separation number is increased, stable low-pressure signals are acquired, the signal-to-noise ratio is larger, and pressure difference signals are more stable.

Description

Technical Field

[0001] The utility model relates to the technical field of automated welding, in particular to a rectifier pressure-taking component and a honeycomb flowmeter. Background Art

[0002] A throttling device with a flow area smaller than the cross-sectional area of ​​a fluid-filled pipe is placed in the pipe. When the fluid stream in the pipe passes through the throttling device, it will experience local contraction or flow separation. At the contraction or separation point, the static pressure will decrease, resulting in a certain pressure difference before and after the throttling device, also known as differential pressure. This pressure difference has a certain functional relationship with the flow rate, so the flow rate can be measured by measuring the pressure difference before and after the throttling device in the pipe.

[0003] The most typical flow sensors currently placed in pipelines and using the pressure difference between total pressure and static pressure to measure flow are orifice plates, standard nozzles, venturi tubes, and various velocity-averaging tubes. Figure 4 As shown, orifice plates, standard nozzles, venturi tubes, etc. create pressure differences through the contraction that occurs when the fluid flows through the measuring piece, while the velocity-averaging tube mainly creates pressure differences through the separation that occurs when the fluid flows through the measuring piece.

[0004] US Patents US5341848 and US5529093 both disclose a plate-shaped rectifying device having a plurality of circular channels and a certain thickness, namely a porous plate, such as Figure 5 As shown in the figure, the size, number and location of the circular channels are properly arranged according to certain rules in order to improve the flow stability and enable the flow to develop fully as quickly as possible.

[0005] U.S. Patent No. 7,051,765 and Chinese Patent No. CN200710162844.6 further disclose a balancing orifice plate, which is also a plate-shaped device with a certain thickness and multiple through-holes arranged in a certain pattern. The size, number, and position of the through-holes on this balancing orifice plate are set according to the requirement of making the Reynolds number in each through-hole equal, in order to balance the flow state, make the flow develop fully as quickly as possible, and improve the measurement accuracy. Chinese Patents CN201110344567.7, CN201120087553.7, CN201220273926.4, etc. also disclose porous orifice plates with similar structures for flow measurement. Chinese Patent No. CN201220323927.5 discloses a Venturi-type porous orifice plate, in which each through-hole has a shape that is thin in the middle and gradually thickens on both sides, i.e., a Venturi-type. When fluid flows through this orifice plate, the Venturi shape is close to a streamlined shape, reducing turbulence and thus reducing the requirement for straight pipe sections. This reduced turbulence also makes the pressure signal more stable, thereby improving measurement accuracy. Chinese patent CN201410241286.2 discloses a multi-hole nozzle that uses one or more sets of centrally symmetrically distributed standard nozzles to achieve the same purpose. Utility Model Content

[0006] Purpose of the utility model: to provide a rectifier pressure taking component and a honeycomb flow meter to solve the above problems existing in the prior art.

[0007] Technical solution: Rectifier and pressure-taking components, including:

[0008] The differential pressure measuring tube has at least two through holes on its side surface, serving as a high pressure port and a low pressure port respectively;

[0009] A plurality of tube bundles are gathered in a preset array rule and installed in the differential pressure measuring tube; the pipeline direction of the tube bundle is the same as that of the differential pressure measuring tube;

[0010] a first damping net, arranged at the front end of the tube bundle;

[0011] The second damping net is arranged at the end of the tube bundle; the first damping net and the second damping net are located between two pressure tapping ports.

[0012] In a further embodiment, the length of the tube bundle is greater than or equal to the inner diameter of a single tube in the tube bundle.

[0013] In a further embodiment, the tube bundle is hexagonal or circular.

[0014] In a further embodiment, numerous tube bundles are connected to each other through their surfaces to form a honeycomb structure; and the honeycomb structure is located between the first damping net and the second damping net.

[0015] In a further embodiment, the mesh size of the damping mesh is determined by the actual flow area and the throttling ratio.

[0016] In a further embodiment, the mesh diameter of the damping net is smaller than the diameter of the tube bundle.

[0017] A honeycomb flowmeter includes any one of a rectifying and pressure-taking component, wherein the rectifying and pressure-taking component includes at least two groups; and further includes a differential pressure sensor and a flow computer, wherein the two collecting ends of the differential pressure sensor are respectively connected to a high-pressure pressure port and a low-pressure pressure port, and the flow computer is electrically connected to the differential pressure sensor.

[0018] In a further embodiment, at least two temperature sensors are further included, which respectively measure the temperature data of the high-pressure port and the low-pressure port and upload the temperature data to the flow computer.

[0019] Beneficial effects:

[0020] 1. This application uses a throttling element covered with damping nets at both ends as a pressure differential signal acquisition component, and uses the differential pressure generated when the fluid flows through the acquisition component to convert the flow rate in the pipeline. At the same time, the damping net's flow-sharing effect is used to evenly organize the flow in the pipeline, guide the airflow in the pipeline to laminar flow, and minimise the flow separation, thereby obtaining the corresponding pressure signal. The differential pressure signal obtained by this solution is more stable, with a higher signal-to-noise ratio, which improves the accuracy and stability of the measurement.

[0021] 2. This application reduces the diameter of the tube bundle and arranges these tube bundles according to the requirements of array aggregation, so that they are aggregated in a honeycomb shape and assembled with two sets of damping nets, thereby reducing turbulence and obtaining a large amount of tiny flow separation, thereby obtaining a relatively stable low-pressure signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of this application.

[0023] Figure 2 It is a schematic diagram of the throttling component structure of this application.

[0024] Figure 3 It is a schematic diagram of the honeycomb flow meter of this application.

[0025] Figure 4 This is a schematic diagram of the first flow separation phenomenon of this application.

[0026] Figure 5 This is a schematic diagram of the second flow separation phenomenon of this application.

[0027] Figure 6 This is a schematic diagram of the structure of the orifice plate, porous orifice plate and damping net of this application.

[0028] The reference numerals in the figure are: airflow 1, differential pressure measuring tube 2, first damping net 3, second damping net 4, tube bundle 5, honeycomb structure 6, orifice plate 7, porous orifice plate 8, flow separation 9, differential pressure sensor 10, high pressure port 11, low pressure port 12. DETAILED DESCRIPTION

[0029] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features known in the art are not described to avoid confusion with the present invention.

[0030] Example 1

[0031] Based on the existing solutions mentioned in the background technology, the existing rectifier is usually composed of one or several bundles of slender channels. If the number of these channels is controlled, the flow will be contracted or separated before and after the channel, thereby generating a differential pressure for flow measurement. At the same time, the density of the channels is reduced, and the channels are arranged according to a certain rule, which is conducive to reducing the mutual influence between the flow separation 9 at the rear of the channel. Figures 4 and 5 As shown, the fluid passes through a perforated plate 7 or a multi-perforated plate 8, and flow separation 9 occurs at the end.

[0032] based on Figures 4 and 5 Based on the principle of throttling, this application proposes a rectifier pressure taking component, which optimizes the throttling component and makes full use of the characteristics of the flow separation 9 generated at its end to continuously and evenly divide it into regions to obtain a stable low-pressure region, a stable low-pressure signal, and thus a stable pressure difference. Figure 1 As shown, the solution of this embodiment is that it includes at least a differential pressure measuring tube 2, multiple tube bundles 5, and a first damping net 3 and a second damping net 4, wherein at least two through holes are opened on the side surface of the differential pressure measuring tube 2, which serve as a high-pressure pressure port 11 and a low-pressure pressure port 12 respectively. Multiple tube bundles 5 are gathered in the form of an array and installed in the differential pressure measuring tube 2, and their installation position is located between the high-pressure pressure port 11 and the low-pressure pressure port 12. The pipeline direction of the tube bundle 5 is the same as the pipeline direction of the differential pressure measuring tube 2. The first damping net 3 is set at the front end of the tube bundle 5, and the second damping net 4 is set at the end of the tube bundle 5. The first damping net 3 and the second damping net 4 are located between the two pressure ports and are installed through the differential pressure measuring tube 2.

[0033] In actual use, the first damping net 3 stabilizes the airflow 1 and generates resistance. The airflow 1 further passes through the tube bundle 5 and is rectified again by the second damping net 4. By reducing the density of the channel, the mutual influence between the flow separation 9 at the rear of the channel is reduced, and the low-pressure signal is obtained. That is, the mesh diameter of the damping net is smaller than the diameter of the tube bundle 5.

[0034] In this embodiment, the differential pressure flow measurement principle formula is as follows: Q = Cd * A * √ (2ΔP / ρ)

[0035] Where Q is the volume flow rate of the fluid, Cd is the outflow coefficient of the fluid (obtained by calibration), A is the area of ​​the circle equivalent to the flowable area, ΔP is the differential pressure between two points of the fluid, and ρ is the density of the fluid.

[0036] like Figure 6 As shown in the figure, the three throttling parts, under the condition that A is the same, will have different Cd outflow coefficients due to the different distribution of the flow holes, which will produce different differential pressure values. Another key point is that the degree of flow separation caused by the three opening methods is different. Figures 4 and 5 As shown, the standard orifice plate 7 produces a strong flow separation 9, and the flow separation 9 fluctuates irregularly. The porous orifice plate 8 decomposes one flow separation into several smaller flow separations 9 that are axially symmetrically distributed, reducing the overall fluctuation. Based on the above scheme and the differential pressure measurement principle formula, the present application further uniformly increases the density of the holes, which will further reduce the scale of the single-hole flow separation and reduce the fluctuation of the total flow separation. Taking into account the technical difficulty and cost of mechanical processing, the present application can open many densely arranged small holes on a circular plate, or directly use a damping net woven by a machine, and the small holes on the surface of the damping net are evenly distributed.

[0037] Further, such as Figure 2 As shown, the parameters of the tube bundle 5 are set, the length of the tube bundle 5 is greater than or equal to the inner diameter of a single tube in the tube bundle, and the tube bundle 5 is set to be hexagonal or circular. Countless tube bundles 5 are connected to each other through their surfaces to form a honeycomb structure 6. The honeycomb structure 6 is located between the first damping net 3 and the second damping net 4. The tube bundle 5 in this embodiment is composed of multiple single tubes combined in an array.

[0038] In this solution, the mesh size of the damping net is determined by the actual flow area and the throttling ratio.

[0039] Example 2

[0040] Based on Example 1, this embodiment proposes a honeycomb flow meter, such as Figure 3As shown, it includes a differential pressure sensor 10 and a flow computer. The two collecting ends of the differential pressure sensor 10 are respectively connected to the high-pressure pressure port 11 and the low-pressure pressure port 12 to obtain high-pressure signals and low-pressure signals respectively. The flow computer is electrically connected to the differential pressure sensor 10, and the flow computer calculates the volume flow of the fluid.

[0041] Since gas is affected by temperature, a temperature sensor is provided in a further optimization scheme. The temperature sensor obtains the temperature data of the high-pressure port 11 and the low-pressure port 12 respectively and uploads the data to the flow computer.

[0042] Based on this, this embodiment provides an existing technical solution to illustrate the above content:

[0043] Configure a differential pressure flowmeter, temperature sensor, and data acquisition system such as a PLC. Install a high-precision temperature sensor for real-time gas temperature monitoring. Choose from thermocouples, resistance temperature detectors, or thermistors. Use the PLC to centrally collect data from the differential pressure flowmeter and temperature sensor. Perform data acquisition and preprocessing: Ensure data from the flowmeter and temperature sensor are collected synchronously to avoid errors caused by time delays. Apply appropriate digital filters, such as low-pass filters, to the collected data to remove noise and improve data quality. Design a compensation algorithm: Use the ideal gas state equation (PV = nRT) to calculate the effect of temperature changes on gas volume. Where P is pressure, V is volume, n is the amount of substance, R is the ideal gas constant, and T is the absolute temperature.

[0044] Based on the measured actual temperature and pressure, the flow rate value is converted to the flow rate value under standard conditions, such as 0°C or 25°C and 1 atmosphere.

[0045]

[0046] Where Qstd is the flow rate under standard conditions, Qmeasured is the actual measured flow rate, Tstd and Pstd are the temperature and pressure under standard conditions, respectively, while Tmeasured and Pmeasured are the actual temperature and pressure during measurement.

[0047] Write program code or script to implement the compensation algorithm in the data acquisition system or PLC to automatically complete the conversion from raw data to flow values ​​under standardized conditions.

[0048] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be interpreted as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. Rectifier pressure taking component, characterized in that: include: The differential pressure measuring tube has at least two through holes on its side surface, serving as a high pressure port and a low pressure port respectively; A plurality of tube bundles are gathered in a preset array rule and installed in the differential pressure measuring tube; the pipeline direction of the tube bundle is the same as that of the differential pressure measuring tube; a first damping net, arranged at the front end of the tube bundle; The second damping net is arranged at the end of the tube bundle; the first damping net and the second damping net are located between two pressure tapping ports.

2. The rectifying and pressure-taking assembly according to claim 1, characterized in that: The length of the tube bundle is greater than or equal to the inner diameter of a single tube in the tube bundle.

3. The rectifying and pressure taking assembly according to claim 1, characterized in that: The tube bundle is hexagonal or circular.

4. The rectifying and pressure-taking assembly according to claim 3, characterized in that: Countless tube bundles are connected to each other through their surfaces to form a honeycomb structure; the honeycomb structure is located between the first damping net and the second damping net.

5. The rectifying and pressure taking assembly according to claim 1, characterized in that: The mesh size of the damping net is determined by the actual flow area and the throttling ratio.

6. The rectifying and pressure taking assembly according to claim 1, characterized in that: The mesh diameter of the damping net is smaller than the diameter of the tube bundle.

7. A honeycomb flow meter, characterized in that: It includes the rectifier pressure-taking assembly according to any one of claims 1 to 6, wherein the rectifier pressure-taking assembly includes at least two groups; it also includes a differential pressure sensor and a flow computer, wherein the two collecting ends of the differential pressure sensor are respectively connected to the high-pressure pressure port and the low-pressure pressure port, and the flow computer is electrically connected to the differential pressure sensor.

8. The honeycomb flow meter according to claim 7, wherein: It also includes at least two temperature sensors, which respectively measure the temperature data of the high-pressure pressure port and the low-pressure pressure port and upload the temperature data to the flow computer.

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