TW201602524A - Fluid flow measurement device - Google Patents

Abstract

A fluid flow measurement device comprises a positioning member for sheathing the outside of a tube and having a through hole, a plug disposed to the through hole, and a pitot assembly. The pitot assembly includes at least a pitot and a calculating unit. The pitot has a connection end passing through the plug and capable of deflecting relative to the plug, and a measurement end capable of performing measurement for different measurement points in accordance with deflection of the connection end. The calculating unit is located at the outside of the positioning member and is connected with the pitot to receive the measurement signal outputted by the pitot to calculate flow velocity and to calculate fluid flow in the tube through numerical integration. Accordingly, the efficacy of good measurement accuracy can be achieved.

Description

Fluid flow measuring device

The present invention relates to a measuring device, and more particularly to a fluid flow measuring device.

When measuring the gas flow or liquid flow in the pipeline flow path, two methods can be used. The first is to directly measure the fluid flow rate; the second is to first measure the hydrostatic pressure and dynamic pressure in the pipeline. After that, the fluid flow rate is converted, and the fluid flow rate is calculated based on the pipe diameter. In general, the second measurement method is more stable than the first measurement method, and the obtained value is more accurate, so it is more commonly used.

However, because the measuring instruments (such as flow meters) are fixed design, that is, located at a specific position inside the pipeline, only a single measurement point can be obtained, so that the measurement accuracy is better. Insufficient, and upstream of the measurement point may also affect the flow velocity distribution within the pipe diameter due to the arrangement of piping such as elbow, expander, reducer, and valve. It will cause turbulence inside the pipeline, etc., resulting in measurement error of the flowmeter.

Therefore, it is an object of the present invention to provide a comparable The flow path performs multi-point measurement to make the fluid flow measuring device with better measurement accuracy.

Thus, the fluid flow measuring device of the present invention is configured to measure the fluid flow in a flow passage of a pipe body, the fluid flow measuring device comprising a positioning member, a stop plug, and a pitot tube assembly. The positioning member is sleeved on the outside of the tube, and the positioning member has a passage communicating with the flow passage, and a through hole communicating the passage with the outside. The stop plug is disposed at the perforation. In addition, the pitot tube assembly includes at least one pitot tube, and a computing unit having a connecting end that is disposed at the stop plug and is displaceable relative to the stop plug, and a tube extending into the tube body a measuring channel in the channel of the positioning member or the measuring end, and the measuring end performs measurement on different measuring points according to the displacement of the connecting end, the calculating unit is located outside the positioning member and is opposite to the skin The host is connected to receive the measurement signal output by the pitot tube and calculate the flow rate, and then calculate the fluid flow rate through numerical integration.

The effect of the invention is that the connection end of the pitot tube can be displaced relative to the stop plug, so that the measuring end can measure different measuring points, thereby enabling the calculating unit to obtain multi-point measuring data. , the average fluid flow can be calculated, and the measurement accuracy is better.

1‧‧‧ Positioning parts

11‧‧‧Circle

111‧‧‧ Storage trough

12‧‧‧ channel

13‧‧‧Perforation

14‧‧‧ joints

2‧‧‧ 止塞塞

21‧‧‧Fixed holes

3‧‧ ‧ Pitot tube components

31‧‧ ‧ Pitot

311‧‧‧Connected end

312‧‧‧Measurement end

32‧‧‧Computation unit

4‧‧‧ tube body

41‧‧‧ flow path

42‧‧‧First pipe section

43‧‧‧Second section

Other features and advantages of the present invention will be apparent from the embodiments of the present invention, wherein: FIG. 1 is an exploded, partial cross-sectional view showing a first embodiment of the fluid flow measuring device of the present invention; Is a partial cross-sectional schematic diagram, with assistance in explaining Figure 1; 3 is a partial cross-sectional view, which assists in explaining FIG. 2, which shows a measurement of a pitot tube to a different measuring point; FIG. 4 is a partial cross-sectional view showing the second part of the fluid flow measuring device of the present invention. Embodiments; and Figure 5 is a partial cross-sectional view showing a third embodiment of the fluid flow measuring device of the present invention.

Referring to Figure 1, a first embodiment of a fluid flow measuring device of the present invention includes a positioning member 1, a stop plug 2, and a pitot tube assembly 3. The positioning member 1 is in the form of a flange or a collar, and is described in the form of a collar in this embodiment. The positioning member 1 has a ring wall 11, a passage 12 defined by the ring wall 11, a through hole 13 formed radially on the ring wall 11, and two joint portions respectively formed on inner sides of the ring wall 11 14. The stop plug 2 is made of a flexible material and is disposed at the through hole 13 of the positioning member 1. The stop plug 2 has a fixing hole 21.

Additionally, the pitot tube assembly 3 includes a pitot tube 31 and a computing unit 32. The pitot tube 31 has a connecting end 311 which is inserted through the fixing hole 21 of the stopper 2 and is displaceable relative to the stopper 2, and a different measurement can be performed according to the displacement of the connecting end 311. The measurement end 312 of the measurement is implemented. The calculation unit 32 includes a differential pressure gauge (not shown), and a numerical integrator (not shown), and the calculation unit 32 is located outside the positioning member 1 and connected to the pitot tube 31 for receiving The measurement signal outputted by the pitot tube 31 is further calculated by the differential pressure gauge, and the average fluid flow rate is calculated by numerical integration of the numerical integrator.

Referring to Figures 2 and 3, in use, the fluid flow measuring device is configured to measure the flow of fluid in a flow passage 41 of a tubular body 4 having a first tubular section 42 and a second tubular section 43. One end of the first pipe segment 42 and one end of the second pipe segment 43 are respectively disposed at the joint portions 14 of the positioning member 1 , and the passage 12 of the positioning member 1 and the first pipe segment 42 of the pipe body 4 are respectively disposed. The flow path 41 and the flow path 41 in the second pipe section 43 communicate with each other. In particular, the fluid passing through the flow passage 41 of the tubular body 4 may be a gas or a liquid. The measuring end 312 of the pitot tube 31 of the pitot tube assembly 3 is then inserted into the channel 12 of the positioning member 1 via the fixing hole 21 and the perforation 13 to measure the passing fluid while matching the skin. The connection end 311 of the host 31 can be raised and lowered relative to the stop plug 2, so that the measurement end 312 can perform measurement on different measurement points, thereby enabling the calculation unit 32 to obtain multi-point measurement data. The flow rate is calculated by the differential pressure gauge of the calculation unit 32, and the average fluid flow rate is calculated by the numerical integration of the numerical integrator, so that the measurement accuracy is better.

In particular, the formula for calculating the flow rate is: Where ν is the flow rate, α is the pitotine correction factor, Δp is the pressure difference between the total pressure and the static pressure, and ρ is the fluid density.

In addition, it is assumed that the flow field formed by the passage 12 of the positioning member 1 and the flow passage 41 in the first tubular section 42 of the tubular body 4 and the flow passage 41 in the second tubular section 43 is axially symmetric, and the analog quantity is high. The measured single point velocity can be multiplied by the local ring to obtain the local volume flow, and the total volume velocity of the fluid passing through the pipe body 4 and the positioning member 1 can be obtained by summing all the simulated speed points, and the calculation formula is as follows: Where Q is the volumetric flow rate, I is the total number of simulated velocity points, and r is the position indicating its radial direction.

Moreover, when the measurement is not performed, the pitot tube 31 can also be pulled outward until the measuring end 312 abuts against the inner surface of the ring wall 11 of the positioning member 1. This reduces the effect on the flow rate through the fluid. When it is necessary to perform the measurement again, only the pitot tube 31 needs to be moved toward the positioning member 1, and the measurement points can be measured again as described above.

In addition, the tubular body 4 adopts a segmented design and is detachably combined with the positioning member 1, so that replacement and maintenance can be more conveniently performed. Especially for online verification, it has great convenience.

In particular, when the tubular body 4 is not in a segmented design, the positioning member 1 can be in the form of a flange and then combined on the tubular body 4 by means of a locking method.

Referring to FIG. 4, a second embodiment of the fluid flow measuring device of the present invention is different from the first embodiment in that the positioning member 1 further has a receiving groove 111 formed on the inner surface of the ring wall 11. The receiving groove 111 is in communication with the through hole 13 , so that when the pitot tube 31 is pulled out without measuring, the measuring end 312 of the pitot tube 31 can be accommodated in the receiving groove 111. The pipette 31 has a small pipe diameter, and can be surely accommodated in the accommodating groove 111 for the passage 12 having a large diameter, so that the flow rate and the flow field are not disturbed when not in use, and the service life of the pitot tube 31 can be prolonged.

Referring to FIG. 5, a third embodiment of the fluid flow measuring device of the present invention is different from the first embodiment in that the pitot tube assembly 3 includes a plurality of pitot tubes 31, and the pitot tubes 31 can be provided by three The pipe is connected to the calculation unit 32 by switching the pipe. The pitot tube assembly 3 is assembled to the positioning member 1 as in the above embodiment, and the measuring end 312 of the pitot tube 31 of the pitot tube assembly 3 is placed at different depth positions, thereby obtaining a plurality of measuring points at the same time. The measured value, in turn, can calculate the average fluid flow rate more quickly.

In summary, the fluid flow measuring device of the present invention is provided with a pitot tube assembly 3 by using the above-mentioned structural design, and the connecting end 311 of the pitot tube 31 can be raised and lowered relative to the stop plug 2 The measurement terminal 312 can perform an online measurement operation on different measurement points, thereby enabling the calculation unit 32 to obtain multi-point measurement data, or setting a majority of the pitot tubes 31 on the positioning member 1 to At the same time, the measured values of a plurality of measuring points are obtained, and the average fluid flow rate is calculated, so that the measuring accuracy is better. In addition, when the measurement is not performed, the pitot tube 31 can be pulled outward until the measuring end 312 is hidden in the receiving slot 111, which not only does not interfere with the flow rate, the flow field, but also extends the pitot tube 31. Service life. When it is necessary to perform the measurement again, only the pitot tube 31 needs to be moved in the direction of the positioning member 1, and the flow measurement can be performed again on different measurement points, so that the use convenience is good. Furthermore, the fluid flow measuring device of the present invention not only applies a fluid to a gas and a liquid, but also can be applied to a fluid pipe of any shape (such as a circular or square pipe), and has an excellent overall versatility. Therefore, the object of the present invention can be achieved.

However, the above is only an embodiment of the present invention, when The scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the present invention in the scope of the invention and the patent specification are still within the scope of the invention.

1‧‧‧ Positioning parts

11‧‧‧Circle

12‧‧‧ channel

13‧‧‧Perforation

14‧‧‧ joints

2‧‧‧ 止塞塞

21‧‧‧Fixed holes

3‧‧ ‧ Pitot tube components

31‧‧ ‧ Pitot

311‧‧‧Connected end

312‧‧‧Measurement end

32‧‧‧Computation unit

4‧‧‧ tube body

41‧‧‧ flow path

42‧‧‧First pipe section

43‧‧‧Second section

Claims (5)

A fluid flow measuring device for measuring a fluid flow in a flow passage of a pipe body, the fluid flow measuring device comprising: a positioning member for sleeved outside the pipe, and the positioning member has a a channel communicating with the channel, and a perforation for communicating the channel to the outside; a stop plug disposed at the perforation; and a pitot tube assembly comprising at least one pitot tube and a computing unit, The pitot tube has a connecting end which is disposed on the stop plug and is displaceable relative to the stop plug, and a measuring end which extends into the flow path of the tube body or the passage of the positioning member, the quantity Measuring and measuring the different measuring points with the displacement of the connecting end, the calculating unit is located outside the positioning member and connected to the pitot tube, and is used for receiving the measuring signal output by the pitot tube The flow rate is calculated and the fluid flow is calculated by numerical integration. The fluid flow measuring device according to claim 1, wherein the positioning member is in the form of a flange or a collar, and has a ring wall defined by the ring wall, the through hole being formed radially The ring wall. The fluid flow measuring device of claim 2, wherein the positioning member further has a receiving groove formed on an inner surface of the ring wall, the receiving groove communicating with the through hole for receiving the pitot tube Measuring terminal. The fluid flow measuring device according to claim 2 or 3, wherein the positioning member further has two joint portions respectively formed on inner sides of the ring wall, and the pipe body has a first pipe segment and a second pipe segment. One end of the first pipe section One end of the second pipe segment is respectively disposed at the joint portion of the positioning member, and the passage of the positioning member is communicated with the flow passage in the first pipe segment of the pipe body and the flow passage in the second pipe segment. The fluid flow measuring device of claim 4, wherein the stop plug is made of a flexible material and is tightly fitted to the through hole, the stop plug having a plug for the pitot tube. The connecting end can be fixedly inserted through the fixing hole.