Constant-speed pipe flow sensor, flow meter and flow control device and method

Abstract

The invention discloses a constant-speed tube flow sensor which comprises at least one pair of pressure tapping tubes and a driving mechanism, plugging pieces are arranged at openings, allowing to-be-measured fluid to enter, of the pressure tapping tubes, and the driving mechanism drives the pressure tapping tubes or the plugging pieces to move relatively. And the plugging sheet leaves the opening when measurement is carried out and plugs the opening when measurement is not carried out. The invention further discloses a flow meter and a flow control device comprising the constant-speed pipe flow sensor. According to the constant-speed pipe flow sensor, accumulation of adhesive substances in the fluid to be measured at the opening can be remarkably reduced, and therefore the cleaning and overhauling period is prolonged.

Description

Technical Field

[0001] The invention relates to the field of gas detection, and in particular to a uniform tube flow sensor, a flow meter having the uniform tube flow sensor, a flow control device having the flow meter, and a method for controlling flow using the flow control device. Background Art

[0002] The averaging tube flowmeter is a differential pressure flowmeter, also known as the Annubar flowmeter or Tobar tube flowmeter. Its working principle is as follows: two pressure tubes with side openings are inserted perpendicular to the radial center axis of the pipe into a closed pipe filled with the measured medium. The high-pressure pressure tube has its opening facing the direction of fluid flow, and the low-pressure pressure tube has its opening facing away from the direction of fluid flow. The two pressure tubes can be separated from each other or combined together. When the fluid passes through the two pressure tubes, the high-pressure and low-pressure pressure tubes each obtain a pressure, and the pressure difference △P between the two pressures is calculated, and the flow rate of the measured medium can be obtained using the Bernoulli equation.

[0003] When the uniform tube flowmeter is used to measure the flow of a fluid containing pollutants that may block the opening of the pressure pipe, the prior art generally adopts a back-blowing anti-blocking design (e.g., CN216206664U, CN219084147U, CN221044432U), an anti-stick coating design (e.g., CN2881558Y, etc.). However, when these uniform tube flowmeters are used for the exhaust airflow of oil smoke in home kitchens or commercial restaurants, the oil particles in the oil smoke will still adhere to and gradually accumulate at the opening of the pressure pipe, causing the pressure pipe to be blocked and affecting the measurement, and such oil blockage is often difficult to remove by back-blowing.

[0004] Therefore, there is still a need for an improved uniform tube flowmeter to solve the above problems. Summary of the invention

[0005] To solve the above technical problems, the inventors have proposed the following uniform tube flow sensor, flow meter, and flow control device and method through creative work. Specifically, the present invention provides the following technical solutions.

[0006] In one aspect, the present invention provides a uniform velocity tube flow sensor, comprising at least a pair of pressure tubes, one of which is a high-pressure pressure tube located upstream in the direction of fluid flow, and the other is a low-pressure pressure tube located downstream in the direction of fluid flow, the high-pressure pressure tube and the low-pressure pressure tube each having an opening, and when the uniform velocity tube flow sensor is in a first state for flow measurement, the opening of the high-pressure pressure tube faces the direction of fluid flow and the opening of the low-pressure pressure tube faces away from the direction of fluid flow, characterized in that a blocking piece is provided at each opening, and the uniform velocity tube flow sensor also includes a driving mechanism to drive the high-pressure pressure tube and the low-pressure pressure tube or the blocking piece to move, so that when the uniform velocity tube flow sensor is in the first state, the blocking piece leaves the opening to allow the fluid to enter each pressure tube through the opening, and when the uniform velocity tube flow sensor is in a second state where no measurement is performed, the blocking piece blocks the opening to prohibit the fluid from entering each pressure tube through the opening.

[0007] Furthermore, the driving mechanism rotates or pulls the pressure taking tube so that the sealing piece leaves or blocks the opening along the circumferential, longitudinal or radial direction of the pressure taking tube, or rotates or pulls the sealing piece so that the sealing piece leaves or blocks the opening along the circumferential, longitudinal or radial direction of the pressure taking tube.

[0008] Further, the high-pressure pressure taking tube and the low-pressure pressure taking tube in the at least one pair of pressure taking tubes are separated from each other, or the high-pressure pressure taking tube and the low-pressure pressure taking tube in the at least one pair of pressure taking tubes are combined with each other.

[0009] Furthermore, the blocking piece includes a first blocking piece wrapped in a semi-enclosed form on the high-pressure pressure taking tube and a second blocking piece wrapped in a semi-enclosed form on the low-pressure pressure taking tube. The first blocking piece and the second blocking piece are connected to each other through a connecting piece and clamped between the high-pressure pressure taking tube and the low-pressure pressure taking tube to allow the high-pressure pressure taking tube and the low-pressure pressure taking tube to rotate around their respective axes, so that in the first state, the opening of the high-pressure pressure taking tube faces the fluid flow direction and the opening of the low-pressure pressure taking tube faces away from the fluid flow direction, and in the second state, the opening of the high-pressure pressure taking tube faces away from the fluid flow direction and is blocked by the first blocking piece, while the opening of the low-pressure pressure taking tube faces the fluid flow direction and is blocked by the second blocking piece.

[0010] Furthermore, the high-pressure and low-pressure pipes are parallel to each other, the maximum size of the first projection of the first plugging piece, the second plugging piece and the connecting piece on the fluid cross section beyond the second projection of the high-pressure and low-pressure pipes on the fluid cross section is not greater than 1% to 10% of the minimum size of the second projection, and the area of ​​the first projection is 1% to 120% of the area of ​​the second projection. Preferably, the first projection is within the range of the second projection, and the area of ​​the first projection is 1% to 50% of the area of ​​the second projection, such as 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, etc.

[0011] Furthermore, a portion of the connecting piece between the high-pressure pressure taking tube and the low-pressure pressure taking tube is at least partially hollowed out, and an area of ​​a third projection of the hollow portion on the longitudinal section of the fluid is 50% to 99% of an area of ​​a fourth projection of the area defined between the high-pressure pressure taking tube and the low-pressure pressure taking tube on the longitudinal section of the fluid, for example, 50%, 55%, 60%, 70%, 80%, 90%, 95%, 99%, etc.

[0012] Furthermore, the connecting member is a plurality of connecting rods, both ends of which are respectively connected to the first blocking piece and the second blocking piece, the longitudinal direction of the connecting rod is parallel to the fluid flow direction, and the maximum size of the cross section of the connecting rod is 5% to 50% of the diameter of the high-pressure pressure taking pipe or the low-pressure pressure taking pipe, for example, 5%, 10%, 20%, 30%, 40%, 50%, etc.

[0013] In another aspect, the present invention provides a uniform tube flowmeter, characterized in that it includes a flow guide tube for guiding fluid to flow from upstream to downstream, a uniform tube flow sensor according to any of the above items installed in the flow guide tube, a differential pressure meter connected to the high-pressure pressure taking tube and the low-pressure pressure taking tube fluid to measure the pressure difference therebetween, and optionally a computing device communicatively connected to the differential pressure meter to calculate the corresponding flow rate based on the pressure difference.

[0014] Furthermore, at least one end of the high-pressure pressure taking tube and the low-pressure pressure taking tube in the uniform tube flow sensor, or at least one end of the first sealing piece and the second sealing piece, extends out of the tube wall of the flow guide tube, and the driving mechanism is dynamically connected to the end to drive the high-pressure pressure taking tube and the low-pressure pressure taking tube to rotate around their axis or move along their longitudinal direction, or drive the first sealing piece and the second sealing piece to rotate around their axis or move along their longitudinal direction.

[0015] In yet another aspect, the present invention provides a flow control device, characterized in that it includes the uniform tube flow meter of any one of the above items, a flow control valve connected to the guide tube of the uniform tube flow meter for controlling the flow of fluid in the guide tube, and an optional control mechanism communicatively connected to the flow control valve, the driving mechanism and the differential pressure meter or the computing device.

[0016] In yet another aspect, the present invention provides a flow control method, comprising:

[0017] S100, providing any of the flow control devices described above, and allowing a fluid whose flow is to be controlled to pass through the flow control device;

[0018] S200, placing the flow sensor in a first state through the driving mechanism, and starting the differential pressure gauge to measure the pressure difference between the high-pressure pressure taking pipe and the low-pressure pressure taking pipe;

[0019] S300, determining a measured flow rate of the fluid according to the pressure difference in S200, and comparing the measured flow rate with an expected flow rate;

[0020] S400, if the flow rate measured in S300 does not match the expected flow rate, adjusting the flow control valve according to the comparison result of S300;

[0021] S500, repeat steps S200 to S400;

[0022] S600: If the flow rate measured in S300 is consistent with the expected flow rate, the flow sensor is placed in a second state through the driving mechanism.

[0023] Furthermore, the fluid whose flow rate is to be controlled is the exhaust gas containing oil smoke exhausted from the range hood to the flue, and the flow rate control method is performed in an intermittent manner.

[0024] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0025] The uniform flow tube flow sensor of the present invention can timely block the openings of the high-pressure and low-pressure pressure pipes through the first and second blocking pieces, and only open the openings when measuring the pressure difference between the two, significantly reducing the accumulation of adherents in the measured fluid in the openings, effectively extending the cleaning and maintenance cycle, and greatly reducing the maintenance workload, which is particularly beneficial in the emission of oil fume exhaust gas in various civil buildings, especially high-rise residential buildings. In contrast, in the anti-blocking solutions such as backwash cleaning and anti-stick coating in the prior art, the openings of the pressure pipes are inevitably exposed to the measured fluid for a long time, and it is difficult to solve the blockage problem caused by the long-term accumulation of adherents contained in oil fume.

[0026] In the description of the present invention, "substantially" does not exclude the meaning of "completely". For example, if a component "substantially does not contain" Y, it may also be completely free of Y. If necessary, "substantially" can be deleted from the definition of the present invention. "Contains" includes both the mentioned factors and is allowed to include additional, uncertain factors. "Approximately" and "around" when used to represent the concentration of each component refer to + / -5%, + / -4%, + / -3%, + / -2%, + / -1%, + / -0.5% of the standard value. "And / or" means that the multiple terms connected by it can be used separately or in any combination with each other.

[0027] In the present invention, examples are generally described by a certain range, which is only for the purpose of concise and clear explanation, and is not intended to limit the present invention. The described range includes sub-ranges, and also includes all individual values ​​within this range. For example, the range of 1 to 6 includes sub-ranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., and also includes individual values ​​within this range, such as 1, 2, 3, 4, 5, 6.

[0028] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the three-dimensional structure of a uniform tube flow sensor according to the present invention in a first state;

[0030] Figure 2 yes Figure 1 The three-dimensional structural schematic diagram of the uniform velocity tube flow sensor in the second state;

[0031] Figure 3 yes Figure 1 A schematic diagram of the three-dimensional structure of a combination of a first blocking piece and a second blocking piece of the uniform tube flow sensor shown;

[0032] Figure 4 is a three-dimensional structural schematic diagram of a uniform tube flowmeter according to the present invention, which includes two sets of Figure 1 The uniform tube flow sensor shown;

[0033] Figure 5 is a schematic diagram of the three-dimensional structure of another uniform-velocity tube flow sensor according to the present invention;

[0034] Figure 6 yes Figure 5 A schematic diagram of a three-dimensional structure of a partially cut-off assembly of a high-pressure pressure-taking tube and a low-pressure pressure-taking tube of a uniform-velocity tube flow sensor;

[0035] Figure 7 yes Figure 5 A schematic diagram of the three-dimensional structure of a combination of a first blocking piece and a second blocking piece of the uniform tube flow sensor shown;

[0036] Figure 8 is a three-dimensional structural diagram of two uniform tube flowmeters according to the present invention, which include two sets of Figure 5 The uniform tube flow sensor shown;

[0037] Fig. 9 yes Figure 8 A longitudinal cross-sectional view of the uniform velocity tube flowmeter shown;

[0038] Fig.10 yes Fig. 9 A partial enlarged view of the uniform tube flowmeter shown in the first state of measuring flow;

[0039] Fig.11 yes Fig. 9 A partial enlarged view of the uniform tube flowmeter shown in the second state where the flow is not measured;

[0040] Fig.12 is a longitudinal cross-sectional view of a flow control device according to the present invention, which includes Figure 4 The uniform tube flow meter shown;

[0041] In the figure:

[0042] 11-high-pressure pressure-taking tube, 12-low-pressure pressure-taking tube, 13-first opening, 14-first blocking plate, 15-second blocking plate, 16-connecting piece, 17-driving mechanism, 18-second opening, 19-longitudinal partition, 2-differential pressure gauge, 3-flow guide tube, 41-first convex part, 42-second convex part, 43-limiting platform, 51-valve body, 52-valve plate, 53-valve shaft, 54-control mechanism. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] refer to Figure 1-3 According to the present invention, a uniform velocity tube flow sensor comprises a pair of pressure-taking tubes which are parallel and separated from each other, one of which is a high-pressure pressure-taking tube 11 located upstream in the direction of fluid flow, and the other is a low-pressure pressure-taking tube 12 located downstream in the direction of fluid flow, the high-pressure pressure-taking tube 11 and the low-pressure pressure-taking tube 12 each having a first opening 13, and when the uniform velocity tube flow sensor is in a first state for flow measurement, the first opening 13 of the high-pressure pressure-taking tube 11 faces the direction of fluid flow and the first opening 13 of the low-pressure pressure-taking tube 12 faces away from the direction of fluid flow.

[0046] A first sealing piece 14 is provided at the first opening 13 of the high-pressure pressure taking pipe 11, which is wrapped around the high-pressure pressure taking pipe 11 in a semi-enclosed form and fits with the outer wall of the high-pressure pressure taking pipe 11; and a second sealing piece 15 is provided at the first opening 13 of the low-pressure pressure taking pipe 12, which is wrapped around the low-pressure pressure taking pipe 12 in a semi-enclosed form and fits with the outer wall of the low-pressure pressure taking pipe 12. The first blocking piece 14 and the second blocking piece 15 are connected to each other through the connecting piece 16 and allow the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 to rotate around their respective axes, so that in the first state, the first opening 13 of the high-pressure pressure taking tube 11 faces the fluid flow direction and the first opening 13 of the low-pressure pressure taking tube 12 faces away from the fluid flow direction and the first blocking piece 14 and the second blocking piece 15 leave the first opening 13 to allow the fluid to enter the first opening 13, thereby performing flow measurement; and in the second state when the fluid flow is not measured, the first opening 13 of the high-pressure pressure taking tube 11 faces away from the fluid flow direction and is blocked by the first blocking piece 14 along the circumference of the high-pressure pressure taking tube 11, while the first opening 13 of the low-pressure pressure taking tube 12 faces the fluid flow direction and is blocked by the second blocking piece 15 along the circumference of the low-pressure pressure taking tube 11 to prevent the fluid from entering the first opening 13, thereby avoiding long-term exposure of the first opening 13 to the fluid, significantly reducing the accumulation of viscous substances in the fluid at the first opening 13, and greatly extending the maintenance cycle.

[0047] In some cases, the connecting member 16 is a plurality of connecting rods, both ends of which are respectively connected to the first blocking piece 14 and the second blocking piece 15, the longitudinal direction of the connecting rod is parallel to the fluid flow direction, and the maximum size of the cross section of the connecting rod is not greater than 50% of the diameter of the high-pressure pressure taking pipe 11 or the low-pressure pressure taking pipe 12, for example, not greater than 5%, 10%, 20%, 30%, 40%, 50%, etc.

[0048] The inventors of the present invention unexpectedly discovered that when the maximum size of the first projection of the first blocking piece 14, the second blocking piece 15 and the connecting piece 16 on the fluid cross section exceeds the second projection of the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 on the fluid cross section and is not greater than 10% of the minimum size of the second projection and the area ratio of the first projection to the second projection is less than or equal to 1.1:1, and at the same time, the portion of the connecting piece 16 between the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 is at least partially hollowed out and the area of ​​the third projection of the hollowed-out portion on the fluid longitudinal section is not greater than 60% of the area of ​​the fourth projection of the area defined between the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 on the fluid longitudinal section, the result of measuring the flow rate using the uniform tube flow sensor shows that the fluctuation range of the measured flow rate is no greater than 3% of the average flow rate.

[0049] A driving mechanism 17 is provided at one end of each of the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12. The driving mechanism 17 can manually, electrically, pneumatically or hydraulically drive the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 to rotate around their axes, thereby switching the uniform velocity tube flow sensor between the first state and the second state.

[0050] In some cases, the driving mechanism 17 is provided with markings, such as markings of color, shape, etc., to help determine the positions of the high-pressure pressure taking pipe 11 and the low-pressure pressure taking pipe 12 .

[0051] Example 2

[0052] refer to Figure 4 According to the present invention, a uniform tube flow meter includes a guide tube 3 for guiding fluid to flow from upstream to downstream, two uniform tube flow sensors according to Example 1 installed perpendicular to each other in the guide tube 3, and a differential pressure meter 2 which is fluidically connected to the high-pressure pressure tube 11 and the low-pressure pressure tube 12 in the uniform tube flow sensor to measure the pressure difference between the two.

[0053] When measuring the flow rate, the fluid to be measured is introduced into the flow guide tube 3 from the upstream, and the high-pressure pressure-taking tube 11 and the low-pressure pressure-taking tube 12 are rotated by the driving mechanism 17, so that the first opening 13 leaves the first blocking piece 14 and the second blocking piece 15 and is exposed to the fluid, thereby the uniform tube flow sensor is in the first state, the fluid enters the high-pressure pressure-taking tube 11 and the low-pressure pressure-taking tube 12 through the first opening 13, and the differential pressure meter 2 measures the pressure difference between the high-pressure pressure-taking tube 11 and the low-pressure pressure-taking tube 12, and then the operator reads the pressure difference data measured by the differential pressure meter 2, and according to the pre-calibrated parameters and formulas, work tables or working curves, the corresponding flow rate can be conveniently determined manually or automatically. In some cases, the differential pressure meter is connected to a computing device (not shown) for automatically calculating the corresponding flow rate according to the pressure difference, and the differential pressure meter or computing device may also include a communication device to transmit the measured pressure difference data or the calculated flow rate data to a designated device.

[0054] When the flow measurement is completed, the high-pressure pressure-taking tube 11 and the low-pressure pressure-taking tube 12 are rotated by the driving mechanism 17, so that the first opening 13 is blocked by the first blocking piece 14 and the second blocking piece 15 and isolated from the fluid, so that the uniform tube flow sensor is in the second state until the next flow measurement is performed. Since the first opening 13 is exposed to the fluid for a very short time, the viscous materials in the fluid rarely adhere to and accumulate at the first opening 13, thereby ensuring that the flow meter can operate stably for a long time.

[0055] Example 3

[0056] refer to Figure 5-7According to another uniform tube flow sensor of the present invention, the pressure tube assembly is composed of a high-pressure pressure tube 11 and a low-pressure pressure tube 12 which are combined with each other, and a plugging piece assembly which is sleeved on the pressure tube assembly and is composed of a first plugging piece 14, a second plugging piece 15 and a connecting piece 16. In the pressure tube assembly, the high-pressure pressure tube 11 and the low-pressure pressure tube 12 are separated by a longitudinal partition 19. A row of first openings 13 are provided along the longitudinal direction of the side wall of the high-pressure pressure tube 11 facing the flow direction of the fluid. Two rows of first openings 13 are provided along the longitudinal direction of the side wall of the low-pressure pressure tube 12 facing the flow direction of the fluid. When the uniform tube flow sensor is in the first state of measuring flow, the plugging piece assembly is located at the first position on the pressure tube assembly, and the first plugging piece 14 and the second plugging piece 15 are respectively provided with second openings 18 at positions corresponding to the first openings 13 on the high-pressure pressure tube 11 and the low-pressure pressure tube 12, thereby allowing the first openings 13 to be exposed to the fluid. When the uniform tube flow sensor is in the second state where the flow is not measured, the blocking piece assembly is located at the second position on the pressure taking tube assembly, and the positions on the first blocking piece 14 and the second blocking piece 15 corresponding to the first openings 13 on the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 are blocked by the first blocking piece 14 or the second blocking piece 15, thereby isolating the first opening 13 from the fluid.

[0057] A driving mechanism 17 is provided at one end of the blocking piece assembly. By pulling the driving mechanism 17 back and forth, the blocking piece assembly can be reciprocated between the first position and the second position along the longitudinal direction of the pressure taking tube assembly, thereby realizing the mutual switching between the first state and the second state.

[0058] Example 4

[0059] refer to Figure 8-11 Another uniform tube flowmeter according to the present invention includes a flow guide tube 3 for guiding fluid to flow from upstream to downstream, two uniform tube flow sensors according to Example 3 arranged perpendicular to each other, and a differential pressure meter 2 which is fluidically connected to the high-pressure pressure tube 11 and the low-pressure pressure tube 12 in the uniform tube flow sensor to measure the pressure difference between the two.

[0060] refer to Fig.10When measuring the flow rate, the fluid to be measured is introduced into the flow guide pipe 3 from the upstream, and the blocking piece assembly including the first blocking piece 14 and the second blocking piece 15 is pushed downward by the driving mechanism 17 until the first protrusion 41 on the driving mechanism 17 abuts against the limit platform 43 on the pressure taking tube assembly including the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12, so that the blocking piece assembly is located at the first position of the pressure taking tube assembly, and at the same time, each first opening 13 is connected with the corresponding second opening 18, so that the first opening 13 is exposed to the fluid, thereby the uniform tube flow sensor is in the first state of measuring the flow rate, and the fluid enters the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12 through the first opening 13, and the differential pressure gauge 2 measures the pressure difference between the high-pressure pressure taking tube 11 and the low-pressure pressure taking tube 12, and then the operator reads the pressure difference data measured by the differential pressure gauge 2, and according to the pre-calibrated parameters and formulas, working tables or working curves, the corresponding flow rate can be conveniently determined manually or automatically. In some cases, the differential pressure meter is communicatively connected to a computing device (not shown) to automatically calculate the corresponding flow rate based on the pressure difference. The differential pressure meter or computing device may also include a communication device to transmit the measured pressure difference data or calculated flow rate data to a designated device.

[0061] refer to Fig.11 When the flow measurement is completed, the plugging piece assembly is pulled upward by the driving mechanism 17 until the second protrusion 42 on the driving mechanism 17 abuts against the inner wall of the flow guide tube 3, so that the plugging piece assembly is located at the second position of the pressure taking tube assembly, and at the same time, each first opening 13 is staggered with the corresponding second opening 18, so that the first opening 13 is blocked by the first plugging piece 14 and the second plugging piece 15 and isolated from the fluid, thereby the uniform tube flow sensor is in the second state of not measuring the flow until the next flow measurement is performed. Since the first opening 13 is exposed to the fluid for a very short time, the viscous materials in the fluid rarely adhere to and accumulate at the first opening 13, thereby ensuring that the flow meter can operate stably for a long time.

[0062] Example 5

[0063] refer to Fig.12The flow control device according to the present invention comprises the uniform tube flow meter according to embodiment 2, a valve body 51 of a flow control valve connected to the flow guide tube 3 of the uniform tube flow meter for controlling the flow of the fluid in the flow guide tube, and the flow control valve further comprises a valve plate 52, a valve shaft 53 and a control mechanism 54. In some cases, the operator adjusts the flow control valve manually or automatically through the control mechanism 54 according to the flow data measured by the uniform tube flow meter so as to adjust the fluid flow to a predetermined value. In other cases, the control mechanism 54 is communicatively connected with the flow control valve, the drive mechanism 17 and the differential pressure meter 2 or an optional computing device, so as to control the drive mechanism 17 to put the uniform tube flow meter in a first state, control the differential pressure meter 2 to measure the pressure difference (and optionally control the computing device to calculate the corresponding flow based on the pressure difference), and then control the valve shaft 53 to rotate the valve plate 52 to adjust the fluid flow; repeat the above steps until the measured fluid flow matches the set or required value; finally, control the drive mechanism 17 to put the uniform tube flow meter in a second state, block the opening 13 to prevent viscous materials in the fluid from adhering to and accumulating at the opening 13.

[0064] In some cases, a flow control method using the flow control device includes:

[0065] S100, allowing the fluid whose flow rate is to be controlled to pass through the flow control device;

[0066] S200, placing the flow sensor in a first state through the driving mechanism, and starting the differential pressure meter 2 to measure the pressure difference between the high-pressure pressure taking pipe 11 and the low-pressure pressure taking pipe 12;

[0067] S300, determining a measured flow rate of the fluid according to the pressure difference in S200, and comparing the measured flow rate with an expected flow rate;

[0068] S400, if the flow rate measured in S300 does not match the expected flow rate, adjusting the flow control valve according to the comparison result of S300;

[0069] S500, repeat steps S200 to S400;

[0070] S600: If the flow rate measured in S300 is consistent with the expected flow rate, the flow sensor is placed in a second state through the driving mechanism.

[0071] In some cases, the flow control device is particularly suitable for controlling the flow of oil-fume waste gas between the range hood and the exhaust flue in high-rise residential buildings and other occasions. In this case, it is usually necessary to measure the flow of oil-fume waste gas on each floor separately only when the equipment conditions change, and then adjust the corresponding flow control valve according to the measured value until each floor can discharge the oil-fume waste gas normally. It can be seen that the flow measurement of oil-fume waste gas only needs to be performed intermittently when needed. By adopting the flow control device of the present invention, the opening 13 of the flow sensor can be exposed to the oil-fume waste gas only during the measurement period, and the opening 13 can be blocked by the sealing piece to isolate it from the oil-fume waste gas during the long period of no measurement, thereby significantly reducing the adhesion and accumulation of viscous substances in the oil-fume waste gas at the opening 13, greatly extending the maintenance cycle of the flow control device, saving a lot of manpower and material resources, and avoiding excessive interference with the normal life of residents.

[0072] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view. The scope of the present invention is defined by the appended claims rather than the above description, and any reference numerals in the claims should not be regarded as limiting the claims involved, and all changes that fall within the meaning of the equivalent elements of the claims are included within the scope of the present invention.

Claims

1. A uniform velocity tube flow sensor, comprising at least one pair of pressure tubes, one of which is a high-pressure pressure tube located upstream of a fluid flow direction, and the other is a low-pressure pressure tube located downstream of the fluid flow direction, the high-pressure pressure tube and the low-pressure pressure tube each having an opening, and when the uniform velocity tube flow sensor is in a first state for flow measurement, the opening of the high-pressure pressure tube faces the fluid flow direction and the opening of the low-pressure pressure tube faces away from the fluid flow direction, characterized in that: A sealing piece is provided at each of the openings, and the uniform velocity tube flow sensor also includes a driving mechanism to drive the high-pressure pressure tube and the low-pressure pressure tube or the sealing piece to move, so that when the uniform velocity tube flow sensor is in a first state, the sealing piece leaves the opening to allow the fluid to enter each pressure tube through the opening, and when the uniform velocity tube flow sensor is in a second state where no measurement is performed, the sealing piece blocks the opening to prohibit the fluid from entering each pressure tube through the opening.

2. The uniform tube flow sensor according to claim 1, characterized in that: The driving mechanism rotates or pulls the pressure taking tube so that the sealing piece leaves or blocks the opening along the circumferential, longitudinal or radial direction of the pressure taking tube, or rotates or pulls the sealing piece so that the sealing piece leaves or blocks the opening along the circumferential, longitudinal or radial direction of the pressure taking tube.

3. The uniform tube flow sensor according to claim 1 or 2, characterized in that: The high-pressure and low-pressure pipes in the at least one pair of pressure pipes are separated from each other, or the high-pressure and low-pressure pipes in the at least one pair of pressure pipes are combined with each other.

4. The uniform tube flow sensor according to claim 3, characterized in that: The blocking piece includes a first blocking piece wrapped in a semi-enclosed form on the high-pressure pressure taking tube and a second blocking piece wrapped in a semi-enclosed form on the low-pressure pressure taking tube. The first blocking piece and the second blocking piece are connected to each other through a connecting piece and clamped between the high-pressure pressure taking tube and the low-pressure pressure taking tube to allow the high-pressure pressure taking tube and the low-pressure pressure taking tube to rotate around their respective axes, so that in the first state, the opening of the high-pressure pressure taking tube faces the fluid flow direction and the opening of the low-pressure pressure taking tube faces away from the fluid flow direction, and in the second state, the opening of the high-pressure pressure taking tube faces away from the fluid flow direction and is blocked by the first blocking piece, while the opening of the low-pressure pressure taking tube faces the fluid flow direction and is blocked by the second blocking piece.

5. The uniform tube flow sensor according to claim 4, characterized in that: The high-pressure pressure taking tube and the low-pressure pressure taking tube are parallel to each other, the maximum dimension of the part of the first projection of the first sealing piece, the second sealing piece and the connecting piece on the fluid cross section that exceeds the second projection of the high-pressure pressure taking tube and the low-pressure pressure taking tube on the fluid cross section is not greater than 1% to 10% of the minimum dimension of the second projection, and the area of ​​the first projection is 1% to 120% of the area of ​​the second projection.

6. The uniform tube flow sensor according to claim 5, characterized in that: The high-pressure pressure taking tube and the low-pressure pressure taking tube are separated from each other, the portion of the connecting piece between the high-pressure pressure taking tube and the low-pressure pressure taking tube is at least partially hollowed out, and the area of ​​the third projection of the hollowed-out portion on the longitudinal section of the fluid is 30% to 99% of the area of ​​the fourth projection of the area defined between the high-pressure pressure taking tube and the low-pressure pressure taking tube on the longitudinal section of the fluid.

7. A uniform tube flowmeter, characterized in that: It comprises a flow guide pipe for guiding fluid to flow from upstream to downstream, the uniform tube flow sensor according to any one of claims 1 to 7 installed in the flow guide pipe, a differential pressure meter connected to the high-pressure pressure taking pipe and the low-pressure pressure taking pipe fluid to measure the pressure difference therebetween, and an optional computing device connected in communication with the differential pressure meter to calculate the corresponding flow according to the pressure difference.

8. A flow control device, characterized in that: It comprises the uniform tube flowmeter according to claim 7, a flow control valve connected to the flow guide tube of the uniform tube flowmeter for controlling the flow of fluid in the flow guide tube, and an optional control mechanism communicatively connected to the flow control valve, the driving mechanism and the differential pressure meter or the computing device.

9. A flow control method, comprising: S100, providing the flow control device according to claim 8, and allowing the fluid whose flow is to be controlled to pass through the flow control device; S200, placing the flow sensor in a first state through the driving mechanism, and starting the differential pressure gauge to measure the pressure difference between the high-pressure pressure taking pipe and the low-pressure pressure taking pipe; S300, determining a measured flow rate of the fluid according to the pressure difference in S200, and comparing the measured flow rate with an expected flow rate; S400, if the flow rate measured in S300 does not match the expected flow rate, adjusting the flow control valve according to the comparison result of S300; S500, repeating steps S200 to S400, if the flow rate measured in S300 is consistent with the expected flow rate, the flow sensor is placed in the second state through the driving mechanism.

10. The flow control method according to claim 9, wherein the fluid whose flow is to be controlled is exhaust gas containing oil smoke exhausted from a range hood to a flue, and the flow control method is performed in an intermittent manner.

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