Large-caliber high-precision Venturi flow sensor

Abstract

The utility model provides a large-caliber high-precision venturi flow sensor which comprises an inlet cylinder section, a venturi contraction section, a venturi throat part, a venturi diffusion section and a venturi lengthening section which are sequentially arranged in the flowing direction, and a first grading ring is arranged outside the inlet cylinder section. A first grading ring is arranged on the inlet cylinder section, the first grading ring is communicated with an inner cavity of the inlet cylinder section, the first grading ring is connected with a pressure tapping pipe used for collecting positive pressure, a second grading ring is arranged on the Venturi throat portion, the second grading ring is communicated with an inner cavity of the Venturi throat portion, the second grading ring is connected with a pressure tapping pipe used for collecting negative pressure, and the pressure tapping pipe is connected with a pressure tapping pipe used for collecting negative pressure. A plurality of pressure tapping holes are formed in the pipe wall surrounding the inlet cylinder section and the Venturi throat part, so that the pressure tapping holes are respectively communicated with the corresponding first grading rings or the corresponding second grading rings, and the pressure tapping device has the advantages of being beneficial to eliminating errors caused when the sensor is installed, improving the precision of the sensor and improving the reliability of the sensor. Meanwhile, the cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the field of flow sensor equipment, in particular to a large-caliber high-precision Venturi flow sensor. Background Art

[0002] The venturi tube is a differential pressure device for measuring flow. It was invented by Italian physicist GB. It consists of an equal diameter inlet section, a contraction section, an equal diameter throat and a diffusion section. The measurement principle is that when the fluid filling the pipe flows through the throttling device in the pipe, the flow velocity will form a local contraction at the throat of the venturi tube, so the flow velocity increases and the static pressure decreases, so a pressure difference is generated before and after the throat of the venturi tube. The greater the fluid flow, the greater the pressure difference generated, so the flow can be measured based on the pressure difference. This measurement method is based on the flow continuity equation (law of conservation of mass) and the Bernoulli equation (law of conservation of energy). It is widely used for flow measurement of air, natural gas, coal gas, water, steam and other fluids. However, when using high-precision Venturi, the site may not have the conditions to install the front and rear straight pipe sections and flow regulators. At the same time, the manufacturing cost of the integrally forged large-diameter Venturi tube is extremely high, which is not conducive to the market application and promotion of the product. At the same time, if there is a pressure tapping hole on only one side, special attention should be paid to the locality and inaccuracy that may exist during measurement, which will also lead to uneven distribution of fluid resistance in the pipeline and affect the flow characteristics of the fluid. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a large-caliber high-precision Venturi flow sensor for solving the technical problems of locality and inaccuracy caused by the position of the pressure taking hole and uneven distribution of fluid resistance in the pipeline in the prior art.

[0004] In order to achieve the above-mentioned and other related purposes, the utility model provides a large-caliber high-precision Venturi flow sensor, comprising:

[0005] An inlet cylinder section, a Venturi contraction section, a Venturi throat section, a Venturi diffusion section and a Venturi extension section are sequentially arranged along the flow direction;

[0006] A first pressure-equalizing ring is provided on the outside of the inlet cylindrical section, the first pressure-equalizing ring is connected to the inner cavity of the inlet cylindrical section, the first pressure-equalizing ring is connected to a pressure-taking pipe for collecting positive pressure, and a second pressure-equalizing ring is provided on the venturi throat, the second pressure-equalizing ring is connected to the inner cavity of the venturi throat, and the second pressure-equalizing ring is connected to a pressure-taking pipe for collecting negative pressure;

[0007] A plurality of pressure-taking holes are arranged on the pipe wall surrounding the inlet cylindrical section and the venturi throat, so the pressure-taking holes are respectively connected to the corresponding first pressure-equalizing ring or the corresponding second pressure-equalizing ring.

[0008] The advantage of adopting the above technical solution is that an inlet cylindrical section, a Venturi contraction section, a Venturi throat, a Venturi diffusion section and a Venturi extension section are arranged in sequence, and a first pressure equalizing ring and a second pressure equalizing ring are respectively arranged on the inlet cylindrical section and the Venturi throat for taking pressure, and a plurality of pressure taking holes are opened on the Venturi inlet cylindrical section and the Venturi throat to be connected with the pressure equalizing ring, which is conducive to eliminating the locality and inaccuracy caused by the installation of the sensor, improving the accuracy of the sensor, and solving the problem of uneven distribution of fluid resistance in the pipeline.

[0009] Optionally, the inner surface roughness parameter of the Venturi throat is 0.8 microns.

[0010] Optionally, the inner surface roughness parameter of the inlet cylindrical section, the Venturi contraction section, the Venturi diffusion section and the Venturi extension section is 3.2 microns.

[0011] Optionally, welding is adopted among the inlet cylindrical section, the Venturi contraction section, the Venturi throat, the Venturi diffusion section and the Venturi extension section.

[0012] Optionally, flanges are further provided at the ends of the inlet cylindrical section and the Venturi extension section that are away from the Venturi throat.

[0013] Optionally, lifting ears are further provided on the outer walls of the Venturi contraction section and the Venturi diffusion section.

[0014] Optionally, the first pressure-equalizing ring and the second pressure-equalizing ring are connected to the corresponding pressure-taking holes via a plurality of half-through components and one full-through component.

[0015] Optionally, the first pressure-equalizing ring and the second pressure-equalizing ring are connected to the corresponding pressure-taking holes through a pipeline.

[0016] Optionally, the angle between two adjacent pressure-taking holes on the same cross section is greater than or equal to 45°.

[0017] Optionally, in order to reduce the manufacturing cost of large-diameter Venturi tubes, the present application uses seamless pipes for the Venturi inlet cylindrical section and the Venturi extension section, uses rolled sheets for the Venturi contraction section and the Venturi diffusion section, and uses forgings for the Venturi throat, and controls the roughness of its inner surface to achieve the purpose of reducing costs and ensuring measurement accuracy.

[0018] As described above, a large-caliber, high-precision Venturi flow sensor of the utility model has the following beneficial effects: a pressure-equalizing ring is selected on the inlet cylindrical section and the Venturi throat in the present application to take the pressure, and a plurality of pressure-taking holes are opened on the Venturi inlet cylindrical section and the Venturi throat to be connected to the pressure-equalizing ring, which is conducive to eliminating the locality and inaccuracy caused by the installation of the sensor, improving the accuracy of the sensor, and solving the problem of uneven distribution of fluid resistance in the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Shown is a schematic diagram of the structure of an embodiment of the utility model;

[0020] Figure 2 Displayed is the whole machine actual flow calibration test data in one embodiment of the utility model;

[0021] Figure 3 Displayed is the whole machine actual flow calibration test data in one embodiment of the utility model;

[0022] Figure 4 It is a schematic diagram of the cross-sectional structure of the first pressure equalizing ring in one embodiment of the utility model.

[0023] Part Number Description

[0024] 1 Inlet cylindrical section

[0025] 101 First pressure equalizing ring

[0026] 2 Venturi contraction section

[0027] 3 Venturi Throat

[0028] 301 Second pressure equalizing ring

[0029] 4 Venturi diffuser

[0030] 5 Venturi extension

[0031] 6 Pressure tapping hole

[0032] 7 Lifting lugs

[0033] 8 Nameplate spacer

[0034] 9 Flange DETAILED DESCRIPTION

[0035] The following is an explanation of the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] See also Figures 1 to 4. It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the utility model in a schematic manner. The illustrations only show the components related to the utility model rather than being drawn according to the number, shape and size of the components during actual implementation. During implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complex. The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read. They are not used to limit the restrictive conditions for the implementation of the utility model, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the utility model without affecting the effects and purposes that can be achieved by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present utility model. Changes or adjustments to their relative relationships should be regarded as the scope of the implementation of the present utility model without substantially changing the technical content.

[0037] See also Figures 1 to 4 As shown, the utility model provides a large-caliber high-precision Venturi flow sensor, comprising:

[0038] An inlet cylindrical section 1, a Venturi contraction section 2, a Venturi throat 3, a Venturi diffusion section 4 and a Venturi extension section 5 are sequentially arranged along the flow direction;

[0039] A first pressure-equalizing ring 101 is provided on the outside of the inlet cylindrical section 1, the first pressure-equalizing ring 101 is connected to the inner cavity of the inlet cylindrical section 1, the first pressure-equalizing ring 101 is connected to a pressure-taking pipe for collecting positive pressure, and the pressure-taking pipe is connected to a corresponding external device; a second pressure-equalizing ring 301 is provided on the venturi throat 3, the second pressure-equalizing ring 301 is connected to the inner cavity of the venturi throat 3, the second pressure-equalizing ring 301 is connected to a pressure-taking pipe for collecting negative pressure, and the pressure-taking pipe is connected to a corresponding external device;

[0040] A plurality of pressure holes 6 are provided on the pipe wall surrounding the inlet cylindrical section 1 and the venturi throat 3 , so the pressure holes 6 are connected to the corresponding first pressure equalizing ring 101 or the corresponding second pressure equalizing ring 301 , respectively.

[0041] Among them, since the roundness, roughness and dimensional deviation of the throat 3 of the Venturi flow sensor have a great influence on the measurement accuracy, the Venturi throat 3 is made of forgings, and its measuring surface is finely polished so that the inner surface roughness parameter of the Venturi throat 3 is 0.8 microns.

[0042] Furthermore, the inlet cylindrical section 1 and the Venturi extension section 5 are made of seamless steel pipes, and their inner surfaces are polished to a roughness parameter of 3.2 microns. The Venturi contraction section 2 and the Venturi diffusion section 4 are rolled into a cylindrical shape using a plate, and their inner surfaces are also polished to a roughness parameter of 3.2 microns, thereby reducing costs while ensuring accurate measurement accuracy.

[0043] It should also be noted that the pressure taking method of the present application is to use a pressure equalizing ring. Five holes are opened on the venturi inlet cylinder section and the venturi throat to connect with the pressure equalizing ring, which is beneficial to eliminate the error caused by the sensor installation and improve the sensor accuracy.

[0044] Exemplarily, the inner surface roughness parameter of the inlet cylindrical section 1, the Venturi contraction section 2, the Venturi diffusion section 4 and the Venturi extension section 5 is 3.2 microns.

[0045] Exemplarily, welding is adopted between the inlet cylindrical section 1 , the Venturi contraction section 2 , the Venturi throat 3 , the Venturi diffusion section 4 and the Venturi extension section 5 .

[0046] It should also be noted that when the Venturi contraction section 2 and the Venturi diffusion section 4 are rolled from plates, they need to be rounded and the weld surface polished after welding.

[0047] Exemplarily, flanges 9 are further provided at the ends of the inlet cylindrical section 1 and the Venturi extension section 5 that are away from the Venturi throat 3 .

[0048] It should also be noted that the flange 9 is provided so that when the corresponding pipelines are connected, flange connection can be performed using bolts to ensure the stability of the connection.

[0049] Exemplarily, lifting ears 7 are further provided on the outer walls of the Venturi contraction section 2 and the Venturi diffusion section 4 .

[0050] It should also be noted that the purpose of providing the lifting lug 7 is to enable lifting through the lifting lug 7 during transfer, transportation and installation, so as to facilitate handling.

[0051] Exemplarily, the first pressure-equalizing ring 101 and the second pressure-equalizing ring 301 are connected to the corresponding pressure-taking holes 6 via a plurality of half-through components and one full-through component.

[0052] It should also be noted that the pressure-taking hole is connected to the corresponding first pressure-equalizing ring 101 and the second pressure-equalizing ring 301 through the half-through component, and the full-through component derives the positive pressure or negative pressure.

[0053] Exemplarily, the first pressure equalizing ring 101 and the second pressure equalizing ring 301 are connected to the corresponding pressure taking holes 6 through pipelines.

[0054] It should also be noted that the positive pressure and negative pressure in the first pressure equalizing ring 101 and the second pressure equalizing ring 301 are led out through the pressure taking pipe.

[0055] Exemplarily, the angle between two adjacent pressure-taking holes 6 on the same cross section is greater than or equal to 45°.

[0056] It should also be noted that five pressure taking holes are arranged around the pressure taking hole 6 to avoid errors caused by the installation position of the sensor.

[0057] Exemplarily, a nameplate pad 8 is also provided on the inner wall of the Venturi diffuser section 4, which is used to protect the surface of the equipment or machine. The nameplate pad 8 is usually installed on the bottom or surface of the equipment. During the installation and use of the machine equipment, the nameplate pad 8 plays the role of protecting the equipment surface, shock absorption, isolation protection, and fixed stability, thereby improving the service life and stability of the equipment.

[0058] When in use, the fluid medium starts to flow into the sensor from this section, and a positive pressure is taken at the inlet cylindrical section 1. When the fluid medium moves from the Venturi contraction section to the Venturi throat 3, the fluid medium begins to gradually contract, the flow velocity increases, and the static pressure decreases. The flow velocity reaches the maximum, the static pressure is the lowest, and the pressure difference is the largest at the throat. A negative pressure is taken at the Venturi throat 3. When the fluid medium passes through the Venturi diffusion section 4, the fluid medium flows through this section, the pressure begins to recover, and the flow velocity decreases. The Venturi extension section 5 mainly plays a role in stabilizing the wake field and facilitating the welding of the flange 9.

[0059] Figure 2 and Figure 3 Two DN800 Venturi flow sensors designed according to this scheme have been calibrated in actual flow water and both can meet the 0.5 level accuracy requirement, proving that the scheme is feasible. Therefore, the Venturi flow sensor not only meets the 0.5 level accuracy requirement, but also has a relatively low manufacturing cost.

[0060] In summary, a large-caliber, high-precision Venturi flow sensor of the utility model is adopted. In this application, an equalizing ring is selected to take pressure on the inlet cylindrical section and the Venturi throat. Five pressure-taking holes are opened on the Venturi inlet cylindrical section 1 and the Venturi throat 3 to be connected with the first equalizing ring 101 or the second equalizing ring 301. This is beneficial to eliminate the locality and inaccuracy caused by the installation of the sensor and improve the accuracy of the sensor. At the same time, seamless steel pipes are used for the inlet cylindrical section 1 and the Venturi extension section 5, the Venturi contraction section 2 and the Venturi diffusion section 4 are made of rolled plates, and the Venturi throat 3 is made of forgings, which can reduce the manufacturing cost to the greatest extent. At the same time, the roughness of the inner surface of the Venturi flow sensor is controlled to ensure the measurement accuracy.

[0061] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A large-caliber high-precision Venturi flow sensor, characterized in that: include: An inlet cylindrical section (1), a Venturi contraction section (2), a Venturi throat (3), a Venturi diffusion section (4) and a Venturi extension section (5) are sequentially arranged along the flow direction; A first pressure-equalizing ring (101) is provided on the outside of the inlet cylindrical section (1), the first pressure-equalizing ring (101) is connected to the inner cavity of the inlet cylindrical section (1), and the first pressure-equalizing ring (101) is connected to a pressure-taking pipe for collecting positive pressure; a second pressure-equalizing ring (301) is provided on the venturi throat (3), the second pressure-equalizing ring (301) is connected to the inner cavity of the venturi throat (3), and the second pressure-equalizing ring (301) is connected to a pressure-taking pipe for collecting negative pressure; A plurality of pressure-taking holes (6) are provided on the pipe wall surrounding the inlet cylindrical section (1) and the Venturi throat (3), so that the pressure-taking holes (6) are respectively connected to the corresponding first pressure-equalizing ring (101) or the corresponding second pressure-equalizing ring (301).

2. A large-caliber high-precision Venturi flow sensor according to claim 1, characterized in that: The inner surface roughness parameter of the Venturi throat (3) is 0.8 micrometers.

3. A large-caliber high-precision Venturi flow sensor according to claim 2, characterized in that: The inner surface roughness parameter of the inlet cylindrical section (1), the Venturi contraction section (2), the Venturi diffusion section (4) and the Venturi extension section (5) is 3.2 microns.

4. A large-caliber high-precision Venturi flow sensor according to claim 3, characterized in that: The inlet cylindrical section (1), the Venturi contraction section (2), the Venturi throat (3), the Venturi diffusion section (4) and the Venturi extension section (5) are all welded.

5. A large-caliber high-precision Venturi flow sensor according to claim 4, characterized in that: The ends of the inlet cylindrical section (1) and the Venturi extension section (5) which are away from the Venturi throat (3) are also provided with flanges (9).

6. A large-caliber high-precision Venturi flow sensor according to claim 5, characterized in that: Lifting ears (7) are also provided on the outer walls of the Venturi contraction section (2) and the Venturi diffusion section (4).

7. A large-caliber high-precision Venturi flow sensor according to claim 6, characterized in that: The first pressure equalizing ring (101) and the second pressure equalizing ring (301) are connected to the corresponding pressure taking holes (6) via a plurality of half-through components and one full-through component.

8. A large-caliber high-precision Venturi flow sensor according to claim 7, characterized in that: The first pressure equalizing ring (101) and the second pressure equalizing ring (301) are connected to the corresponding pressure taking holes (6) via pipelines.

9. A large-caliber high-precision Venturi flow sensor according to claim 8, characterized in that: The angle between two adjacent pressure-taking holes (6) on the same cross section is greater than or equal to 45°.

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