Flue gas flow measuring device for large-pipe-diameter flue
By increasing the diameter of the detection rod, increasing the number of pressure-taking holes and apertures in the flue gas flow measurement device of the large pipe diameter flue gas flow, and installing a back-purging valve, the problems of insufficient strength of the detection rod, low metering accuracy and easy blockage of the static pressure hole are solved, and continuous, accurate and reliable measurement of the flue gas flow is achieved.
Patent Information
- Application Number
- CN202421497737.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-27
AI Technical Summary
The existing flue gas flow measurement devices have problems such as insufficient strength of the detection rod, low metering accuracy and easy blockage of the static pressure hole in the large pipe diameter flue, resulting in low measurement stability and accuracy.
A large-pipe flue gas flow measurement device is designed. By increasing the diameter of the detection rod probe, increasing the number of pressure holes and apertures, and installing a back-purging valve at the pressure hole, a timing high-pressure air source purge is achieved to prevent smoke and dust from deposition.
It effectively improves the strength of the detection rod, reduces additional metering errors caused by flow velocity distortion, prevents static pressure holes from being blocked, realizes continuous, accurate and reliable measurement of large-diameter flue gas flow, and improves detection efficiency.
Smart Images
Figure CN222671144U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of online instrument measurement, in particular to a large-diameter flue gas flow measurement device. Background Art
[0002] At present, carbon emission measurement has always been in a rough state, which only estimates the annual emission based on the flue gas volume measurement, or estimates the annual flue gas emission based on the lower calorific value of coal and the excess air coefficient, and the amount of air required to burn each ton of coal. The error of this estimation is as high as more than 5%. It is difficult to achieve the expected accuracy and reliability of carbon emissions, especially for large-diameter flue gas flow measurement. First, the diameter of the flue gas pipeline is large; second, the flue gas medium contains a lot of dust, high temperature, and strong corrosiveness; third, the flue gas static pressure is small and the flow rate is low; in addition, the working conditions at the flue gas measurement site are relatively poor, and most of them are cement reinforced flues, which are not easy to install and maintain. Existing flue gas flow measurement instruments have the following shortcomings: the detection rod is not strong enough. The flow meters that are widely used for flue gas measurement include Viabar, Annubar, conventional average velocity tube, etc. The diameter of the detection rod probe of this type of flow meter is generally ≤Ø28. There are many accidents such as the flow meter detection rod breaking and bending during operation; the measurement accuracy is not high. The flue gas pipeline usually has the characteristics of large diameter, insufficient straight pipe section and low pressure, which leads to flow velocity distortion in the pipeline and it is difficult to form a fully developed pipe flow. Single-point pressure measurement or radial pressure measurement is often difficult to characterize the average flow velocity in the pipeline, which will bring additional errors; blockage problem. The flue gas medium has a large dust content. The static pressure hole is blocked during operation, which affects the measurement and increases the maintenance and repair workload. Utility Model Content
[0003] The utility model provides a large-diameter flue gas flow measurement device to solve the problems existing in the above background.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A flue gas flow measurement device for a large-diameter flue comprises a flue, wherein a plurality of average-velocity tube flow meters are penetrated through the side wall of the flue, a connecting tee is provided on the side where the average-velocity tube flow meter extends out of the flue, the connecting tee is connected to a three-valve group, and the three-valve group is connected to an intelligent differential pressure transmitter, and a high-pressure chamber and a low-pressure chamber are provided on the inner wall where the average-velocity tube flow meter extends into the flue.
[0006] Furthermore, a plurality of mounting holes are provided on the side wall of the flue, and the average velocity tube flow meters are arranged through the mounting holes.
[0007] Furthermore, a pressure-conducting pipe is connected in parallel to one side of the averaging tube flowmeter extending out of the flue, and the connecting tee is connected to the pressure-conducting pipe.
[0008] Furthermore, a plurality of high-pressure pressure holes are opened on the inner wall of one side of the average-velocity tube flowmeter extending into the flue, and the high-pressure chamber is arranged close to the high-pressure pressure holes, and a plurality of low-pressure pressure holes are opened on the inner wall of the other side of the average-velocity tube flowmeter extending into the flue, and the low-pressure chamber is arranged close to the low-pressure pressure holes.
[0009] Furthermore, a back-purge valve can be detachably provided on the side wall where the average velocity tube flowmeter extends into the flue.
[0010] The utility model has the following beneficial effects:
[0011] The utility model provides a large-diameter flue gas flow measurement device, which is mainly composed of a mounting hole, a flow meter, a pressure pipe, a connecting tee, a differential pressure transmitter and a pressure taking hole. By increasing the diameter of the detection rod probe to ensure the strength of the detection rod, and then increasing the diameter and number of the detection rod pressure taking holes, the number of detection rods is increased on the same cross-section of the flue, and the point flow velocity or line flow velocity measurement is upgraded to the surface flow velocity measurement, which effectively reduces the additional metering error caused by the flow velocity distortion. At the same time, a back-purge valve is connected to the probe pressure taking hole, and a high-pressure gas source is used for regular purge to prevent smoke and dust deposition. It can realize continuous, accurate and reliable measurement of large-diameter flue gas flow, improve the overall detection efficiency, and solve the problem that in the current flue gas measurement process of carbon emission pipelines, the detection rod strength is generally poor, the metering accuracy is not high, and the static pressure hole is very easy to be blocked, which ultimately affects the overall detection stability and accuracy of the flue gas flow. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0013] Figure 2 It is a schematic diagram of the structure of the average velocity tube flowmeter of the utility model.
[0014] The meanings of the reference numerals are as follows:
[0015] 1. Flue; 2. Mounting hole; 3. Average velocity tube flowmeter; 4. Pressure pipe; 5. Connecting tee; 6. Three-valve group; 7. Intelligent differential pressure transmitter; 8. High-pressure pressure hole; 9. Low-pressure pressure hole; 10. High-pressure chamber; 11. Low-pressure chamber; 12. Back-purge valve. DETAILED DESCRIPTION
[0016] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments.
[0017] like Figure 1-2As shown, a flue gas flow measurement device for a large-diameter flue comprises a flue 1, wherein a plurality of average-velocity tube flow meters 3 are penetrated through the side wall of the flue 1, a connecting tee 5 is provided on the side where the average-velocity tube flow meter 3 extends out of the flue 1, the connecting tee 5 is connected to a three-valve group 6, and the three-valve group 6 is connected to an intelligent differential pressure transmitter 7, and a high-pressure chamber 10 and a low-pressure chamber 11 are provided at the inner wall where the average-velocity tube flow meter 3 extends into the flue 1.
[0018] A plurality of mounting holes 2 are provided on the side wall of the flue 1 , and the average velocity tube flowmeters 3 are arranged through the mounting holes 2 .
[0019] One side of the average velocity tube flowmeter 3 extending out of the flue 1 is connected in parallel with a pressure-conducting pipe 4 , and the connecting tee 5 is connected to the pressure-conducting pipe 4 .
[0020] A plurality of high-pressure holes 8 are provided on the inner wall of one side where the average-velocity tube flowmeter 3 extends into the flue 1, and the high-pressure chamber 10 is arranged close to the high-pressure pressure holes 8. A plurality of low-pressure holes 9 are provided on the inner wall of the other side where the average-velocity tube flowmeter 3 extends into the flue 1, and the low-pressure chamber 11 is arranged close to the low-pressure pressure holes 9.
[0021] A back-purge valve 12 is also detachably provided at the side wall where the average velocity tube flowmeter 3 extends into the flue 1 .
[0022] In specific applications, the utility model firstly opens three groups of mounting holes 2 on the top of the flue 1, then selects an average velocity tube flowmeter 3 with a detection rod probe having a diameter of Ø100mm, then increases the number of high-pressure pressure holes 8 and low-pressure pressure holes 9 of the detection rod, and increases their apertures to Ø12mm, then installs a back-purge valve 12 on the side wall of the average velocity tube flowmeter 3, and finally installs the average velocity tube flowmeter 3 with optimized structure through the mounting holes 2, then installs the pressure guiding pipe 4 on the top of the average velocity tube flowmeter 3, and then installs the connecting tee 5, the three-valve group 6 and the differential pressure transmitter 7 in sequence. By increasing the diameter of the detection rod of the average velocity tube flowmeter 3, the strength of the detection rod is effectively improved to prevent Its breakage affects the progress of flue gas detection; by increasing the number of detection rods of the average-velocity tube flowmeter 3 on the same cross-section of the flue 1, the point flow velocity or line flow velocity measurement is effectively upgraded to the surface flow velocity measurement, reducing the additional metering error caused by the flow velocity distortion, and then the back-purge valve 12 is connected to the side of the high-pressure pressure hole 8 and the low-pressure pressure hole 9 of the detection rod of the average-velocity tube flowmeter 3, so that the high-pressure gas source can be used to regularly purge the high-pressure pressure hole 8 and the low-pressure pressure hole 9, effectively preventing the deposition of smoke and dust, and further improving the continuity of flue gas measurement, thereby greatly reducing the workload of manual cleaning and maintenance, and improving the overall efficiency and accuracy of large-diameter flue gas flow measurement. Therefore, the device has good practicality.
Claims
1. A device for measuring flue gas flow in a large-diameter flue, comprising a flue (1), characterized in that: A plurality of average velocity tube flowmeters (3) are provided through the side wall of the flue (1); a connecting tee (5) is provided on the side where the average velocity tube flowmeter (3) extends out of the flue (1); the connecting tee (5) is connected to a three-valve group (6); the three-valve group (6) is connected to an intelligent differential pressure transmitter (7); and a high-pressure chamber (10) and a low-pressure chamber (11) are provided on the inner wall where the average velocity tube flowmeter (3) extends into the flue (1).
2. A large-diameter flue gas flow measurement device according to claim 1, characterized in that: A plurality of mounting holes (2) are provided on the side wall of the flue (1), and the average velocity tube flow meters (3) are arranged through the mounting holes (2).
3. A large-diameter flue gas flow measurement device according to claim 2, characterized in that: A pressure-conducting pipe (4) is connected in parallel to the side of the averaging tube flowmeter (3) extending out of the flue (1), and the connecting tee (5) is connected to the pressure-conducting pipe (4).
4. A large-diameter flue gas flow measurement device according to claim 3, characterized in that: A plurality of high-pressure holes (8) are provided on the inner wall of one side of the average-velocity tube flowmeter (3) extending into the flue (1), and the high-pressure chamber (10) is arranged close to the high-pressure holes (8); a plurality of low-pressure holes (9) are provided on the inner wall of the other side of the average-velocity tube flowmeter (3) extending into the flue (1), and the low-pressure chamber (11) is arranged close to the low-pressure holes (9).
5. A large-diameter flue gas flow measurement device according to claim 4, characterized in that: A back-purge valve (12) is also detachably provided at the side wall of the averaging tube flowmeter (3) extending into the flue (1).