Device and method for detecting gas flow rate of large-diameter pipe body based on honeycomb structure

Abstract

The invention belongs to the technical field of gas emission amount detection, is particularly suitable for monitoring CO2 emission amount of a power plant and online detection of factory waste gas emission amount or emission amount of a certain component, and particularly relates to a device and a method for detecting the gas flow rate of a large-diameter pipe body based on a honeycomb structure. The device for detecting the gas flow rate of the large-diameter pipe body based on the honeycomb structure comprises a detection sub-unit, and a flow rate detection device is arranged on the detection sub-unit; and the detection sub-units are arranged in a honeycomb structure. According to the invention, the large aperture is divided into a plurality of honeycomb tube combinations, so that the problem of inaccurate wind speed measurement caused by the fringe effect of the large aperture can be effectively solved. The large-caliber wind speed can be accurately measured by adopting a honeycomb structure and a phase array measurement mode, the measurement accuracy guarantee value is within 2%, and the resistance drop loss is smaller than 5%. According to the measuring device, a honeycomb structure can be printed into an assembly through 3D printing, then the assembly is spliced and installed on site, and installation and maintenance are very convenient.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas emission detection, and is particularly suitable for monitoring CO2 emissions from power plants, online detection of factory waste gas emissions or emissions of a certain component, and specifically, is a device and method for detecting gas flow velocity in large-diameter pipes based on a honeycomb structure. Background Art

[0002] The primary and secondary air speeds and volumes used in peak-shaving power plants, carbon dioxide emissions from factories or installations, and atmospheric environmental governance emissions are all subject to the challenge of inaccurate gas flow measurement in large-diameter pipelines. While domestic measurement optimization is currently being pursued through multi-point measurement technology, such as the utility model patent "A Flowmeter for Multi-Point Measurement in Large-Diameter Pipelines" (CN201920544655.3), which utilizes multi-point, multi-unit measurement to more comprehensively measure the average flow velocity within the pipeline, and is used in conjunction with a differential pressure transmitter, display instrument, or computer, it can measure fluid flow within large-diameter pipelines. This is more accurate and reliable than conventional single-point flowmeters, but because large-diameter wind speed is affected by the channel diameter and the flow field varies across the entire cross-section due to numerous factors, the measured flow or velocity error remains between 5% and 10%. In addition, "Flowmeter Suitable for Large-diameter Pipeline Flow Measurement" (Publication No.: CN108318090B) uses a multi-stage combined rectifier to study and achieve a better rectification effect by using a multi-stage contraction combined rectification method. It can also achieve a good flow velocity distribution profile without a straight pipe section, greatly improving the measurement accuracy of large-diameter flow. The flow measurement accuracy of this device can reach within ±2.5%, but its pressure loss is between 17% and 35%. For large-diameter flow, more power is required to achieve it, and the power of the fan needs to be greatly increased. Summary of the Invention

[0003] The present invention provides a device and method for detecting the gas flow velocity of a large-diameter pipe based on a honeycomb structure, which can improve the measurement accuracy of the flue gas flow velocity in the large-diameter pipe.

[0004] The present invention is achieved by the following methods: A device for detecting the gas flow rate of a large-diameter pipe based on a honeycomb structure includes a detection subunit, on which a flow rate detection device is provided; each of the detection subunits is arranged in a honeycomb structure.

[0005] The detection subunit is a detection tube, and the cross section of the detection tube is one or more of a regular hexagon, a circle, and a quadrilateral.

[0006] The flow velocity detection device is one of a differential pressure flow meter, an electromagnetic flow meter, and an ultrasonic flow meter.

[0007] The equivalent diameter of the detection tube is DN50~DN400; the length of the detection tube is 3~15 times the equivalent length of the detection tube.

[0008] Preferably, the device for detecting the gas flow rate of a large-diameter pipe based on a honeycomb structure further comprises a fixed frame that can be fixed to the inner wall of the large-diameter pipe, wherein the fixed frame has detection sub-units evenly distributed in a honeycomb array. Several of the fixed frames are fixedly installed in the large-diameter pipe for measuring the gas flow rate; and the several fixed frames are at different heights within the large-diameter pipe for measuring the gas flow rate.

[0009] The method for detecting the gas flow rate of a large-diameter pipe based on a honeycomb structure includes the following steps: S1. A detachable fixed frame is installed on the inner wall of the large-diameter tube where the gas flow rate needs to be measured. The fixed frame is filled with detection tubes evenly distributed in a honeycomb structure. S2. Detecting the gas flow rate of each detection tube by a flow rate detection device; S3. Adjust the position of the fixed frame in the large-diameter tube to further detect the gas flow rate at different positions in the large-diameter tube; S4. Perform statistics and software correction on the detection results of steps S2 and S3 to finally obtain the gas flow rate of the large-diameter pipe.

[0010] Beneficial effects of the present invention: 1. The present invention divides the large diameter into multiple honeycomb tubes, which can effectively solve the problem of inaccurate wind speed measurement due to the edge effect of large diameter. 2. This invention uses a honeycomb structure and phased array measurement method to accurately measure large-diameter wind speeds, with a guaranteed measurement accuracy of less than 2% and a drag drop loss of less than 5%. This measurement device can be 3D printed into components using the honeycomb structure, which can then be assembled on-site, making installation and maintenance very convenient. 3. The present invention can adapt to different large-diameter forms. No matter whether it is a large-diameter pipeline type square tube, round tube, elliptical tube, special-shaped tube, etc., accurate measurement can be achieved through the honeycomb structure and phase array measurement method. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic structural diagram of Example 1 of the present invention; Figure 2 This is a schematic structural diagram of Example 2 of the present invention; Figure 3 This is a schematic structural diagram of Example 3 of the present invention; In the figure: 1—detection tube; 2—flow rate detection device; 3—fixed frame. DETAILED DESCRIPTION

[0012] See also Figure 1-Figure 3A device for detecting the gas flow rate of a large-diameter pipe based on a honeycomb structure includes a detection subunit, on which a flow rate detection device is provided; each of the detection subunits is arranged in a honeycomb structure.

[0013] The detection subunit is a detection tube with a cross-section of one or more of a regular hexagon, a circle, or a square. The material selection for the detection tube depends on the gas medium. If the gas contains corrosive media, corrosion-resistant metals can be used, or non-metallic materials can be used. The honeycomb tube structure can have a cross-section of one or more of a hexagon, a circle, or a square. For a compact structure, reduced material usage, and effective reduction in system resistance drop, a regular square or hexagonal shape is preferred. Fabrication can be achieved through 3D printing or thin-plate welding.

[0014] The flow velocity detection device is one of a differential pressure flow meter, an electromagnetic flow meter, and an ultrasonic flow meter.

[0015] The equivalent diameter of the detection tube is DN50-DN400; the length of the detection tube is 5-10 times the equivalent length of the detection tube. The detection tube can be manufactured in sections and then assembled together. The honeycomb structure has no size limit, but for accurate measurement, the equivalent diameter is preferably DN50-DN400. The honeycomb tube length is 5-10 times the equivalent length of the honeycomb tube to ensure stable gas flow after gas rectification, which is conducive to accurate gas detection.

[0016] Preferably, the device for detecting the gas flow rate of a large-diameter pipe based on a honeycomb structure further comprises a fixed frame that can be fixed to the inner wall of the large-diameter pipe, wherein the fixed frame has detection sub-units evenly distributed in a honeycomb array. Several of the fixed frames are fixedly installed in the large-diameter pipe for measuring the gas flow rate; and the several fixed frames are at different heights within the large-diameter pipe for measuring the gas flow rate.

[0017] The method for detecting the gas flow rate of a large-diameter pipe based on a honeycomb structure includes the following steps: S1. A detachable fixed frame is installed on the inner wall of the large-diameter tube where the gas flow rate needs to be measured. The fixed frame is filled with detection tubes evenly distributed in a honeycomb structure. S2. Detecting the gas flow rate of each detection tube by a flow rate detection device; S3. Adjust the position of the fixed frame in the large-diameter tube to further detect the gas flow rate at different positions in the large-diameter tube; S4. Perform statistics and software correction on the detection results of steps S2 and S3 to finally obtain the gas flow rate of the large-diameter pipe.

[0018] Example 1 See also Figure 1A device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure comprises a large-diameter pipe with a fixed frame 3 welded to the inner wall thereof. Within the fixed frame 3 are detection tubes 1 uniformly distributed in a honeycomb array. A flow velocity detection device 2 is mounted on the detection tubes 1. The flow velocity detection device 2 is a differential pressure flowmeter. The detection tubes have a regular hexagonal cross-section. The detection tubes 1 have an equivalent diameter of DN50 and a length of 250 mm.

[0019] Example 2 See also Figure 2 A device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure comprises a large-diameter pipe body, a fixed frame 3 welded to the inner wall of the large-diameter pipe body, and detection tubes 1 uniformly distributed in a honeycomb array within the fixed frame 3. Detection tubes 1 are provided with a flow velocity detection device 2. Flow velocity detection device 2 is an electromagnetic flowmeter. The detection tubes have a circular cross-section. The equivalent diameter of the detection tubes is DN400, and the length of the detection tubes is 4000 mm.

[0020] Example 3 See also Figure 3 A device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure comprises a large-diameter pipe body. A fixed frame 3 is welded to the inner wall of the large-diameter pipe body. Within the fixed frame 3 are detection tubes 1 evenly distributed in a honeycomb array. A flow velocity detection device 2 is mounted on the detection tubes 1. The flow velocity detection device 2 is an ultrasonic flowmeter. The detection tubes 1 have a square cross-section, an equivalent diameter of DN200, and a length of 1600 mm.

Claims

1. A device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure, characterized by: It comprises detection subunits, each of which is provided with a flow rate detection device; each of the detection subunits is arranged in a honeycomb structure.

2. The device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure according to claim 1, characterized in that: The detection subunit is a detection tube, and the cross section of the detection tube is one or more of a regular hexagon, a circle, and a quadrilateral.

3. The device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure according to claim 1, characterized in that: The flow velocity detection device is one of a differential pressure flow meter, an electromagnetic flow meter, and an ultrasonic flow meter.

4. The device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure according to claim 2, characterized in that: The equivalent diameter of the detection tube is DN50~DN400; the length of the detection tube is 3~15 times the equivalent length of the detection tube.

5. The device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure according to any one of claims 1 to 4, characterized in that: The invention comprises a fixed frame which can be fixed on the inner wall of a large-diameter pipe body, wherein the fixed frame is provided with detection sub-units uniformly distributed in a honeycomb structure.

6. The device for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure according to claim 5, characterized in that: The plurality of fixed frames are fixedly arranged in the large-diameter tube body of the gas flow rate to be measured; the plurality of fixed frames are at different heights in the large-diameter tube body of the gas flow rate to be measured.

7. A method for detecting gas flow velocity in a large-diameter pipe based on a honeycomb structure, characterized in that: The steps include: S1. A detachable fixed frame is installed on the inner wall of the large-diameter tube where the gas flow rate needs to be measured. The fixed frame is filled with detection tubes evenly distributed in a honeycomb structure. S2. Detecting the gas flow rate of each detection tube by a flow rate detection device; S3, further detecting the gas flow rate at different positions within the large-diameter tube; S4. Perform statistics and software correction on the detection results of steps S2 and S3 to finally obtain the gas flow rate of the large-diameter pipe.

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