CN210834953U - Pitot tube sensor for variable air volume valve - Google Patents

Abstract

The utility model discloses a Pitot tube sensor for a variable air volume valve. Partition flanges are respectively arranged on both sides of a pipe body; one end of the pipe body is a concave-shaped structure; A card slot is provided, the other end of the pipe body is a convex-shaped structure, and the pipe body is located on both sides of the convex-shaped structure. The two ends of the pipe body located in the dynamic pressure inner pipe are respectively provided with upper end sealing ring grooves; the two ends of the pipe body located in the static pressure inner pipe are respectively provided with lower end sealing ring grooves, the structure of the utility model is reasonable, and the continuous combination of multiple pipe bodies can be realized. , to realize the adjustment and control of the length. There are partition flanges on both sides of the pipe body, which can avoid the excessive interference of the pitot tube to the measured fluid, ensure the control accuracy of the pitot tube and the stability of the fluid, and more effectively realize the air conditioning system. Precise control.

Description

A Pitot Sensor for Variable Air Volume Valves

technical field

The utility model relates to the field of physics, in particular to an air velocity measurement technology, in particular to a Pitot tube sensor for a variable air volume valve.

Background technique

In a variable air volume air conditioning system, the air volume flowing through the variable air volume terminal device must be checked and controlled. A wind speed sensor is a device used to measure wind speed. Through the wind speed sensor, the flow law of the air flow can be understood, and the volume flow of the air flowing through the variable air volume terminal device can also be calculated, so as to effectively control the air supply volume of each terminal device and even the entire air conditioning system.

There are various methods of wind speed measurement, and differences in wind speed detection range, accuracy requirements, and use requirements are the main basis for selecting wind speed sensors. The methods of measuring wind speed include air pressure method, mechanical method and heat dissipation rate method. The air pressure method is to obtain the wind speed by measuring the difference between the total pressure and the static pressure, such as a pitot tube wind speed sensor; the mechanical method is to use the dynamic pressure of the flowing gas to drive the mechanical device to rotate, such as a propeller wind speed sensor, and the speed of the impeller passes through an electronic counting device. , to display the measured wind speed; the heat dissipation rate method is designed based on the principle of the paired relationship between the flow rate and the heat dissipation rate, or to measure the time of equal heat dissipation, or to measure the change of temperature, or to maintain the change of the heating current at the original temperature to determine the wind speed. With the development of modern science and technology, some new wind speed sensors such as laser and ultrasonic are also used in wind speed detection.

Pitot tube is a pressure measuring tube, which is widely used because of its simple structure, convenient use and perfect theoretical research. The Pitot tube detects the flow rate based on the differential pressure caused by the fluid flow.

A standard pitot tube is a thin metal tube bent at a right angle, which consists of a sensing head, an outer tube, an inner tube, a pipe string, and a full pressure and static pressure lead-out conduit. At the end of the head of the pitot tube, there is a small hole facing the airflow, and the plane of the small hole is perpendicular to the flow direction of the fluid. At the place downstream of the head of the pitot tube, a plurality of small holes are opened around the outer side of the pipe wall, and the direction of fluid flow is tangent to the hole surface of these small holes. The small hole on the top and the small hole on the side are respectively connected with two pipelines that do not communicate with each other. In addition to the static pressure of the fluid itself, the pressure entering the small hole at the top of the pitot tube also contains the part of the pressure converted from kinetic energy (dynamic pressure) after the fluid stagnates. The pressure of the hole is simply the static pressure of the fluid.

According to the total air pressure value and static pressure value measured by the pitot tube, the velocity of the fluid at the measuring point can be obtained according to the following formula: υ=§√2(p1-p2)/ρ, where υ-----measuring point Speed of airflow at the place, m/s; p1----full pressure value measured by pitot tube, Pa; p2----static pressure value measured by pitot tube, Pa; ρ----fluid density, kg/m ³ ; §---- Pitot tube shape and structure correction factor.

Pitot tube shape and structure correction factor § obtained by experiment, this value is different due to various forms of pitot tube. For a standard pitot tube, the § value can be kept between 1.02-1.04 and is constant over a larger range of Reynolds numbers.

式中△p-----皮托管式风速传感器的输出动压，Pa；F-----皮托管式风速传感器的放大系数，F值最大为3，一般F≥2。Pitot tube wind speed sensor itself cannot output electrical signal, only output differential pressure signal. Therefore, the above formula can also be transformed into

In the formula, △p-----the output dynamic pressure of the pitot tube wind speed sensor, Pa; F-----the amplification factor of the pitot tube wind speed sensor, the maximum F value is 3, and generally F≥2.

Pitot tubes can only measure the flow velocity at a certain point, and when the fluid flows in the pipe, the flow velocity at each point on the same section is different. In order to obtain the flow rate, the average flow velocity of the fluid must be known. In the variable air volume terminal device, due to the large section at the speed measuring point, the flow velocity at one point cannot reflect the average flow velocity of the section, so it is necessary to use a pitot tube to select several points on the same section for measurement, and take the average value of these measurement points as Average flow rate through the VAV terminal. However, it is inconvenient to perform multiple measurements at multiple points. In fact, people often use a deformed pitot tube, that is, an average velocity tube, to measure the flow velocity in a circular pipe. It averages the dynamic pressures of each measuring point obtained on the measured section to directly obtain the average velocity.

This uniform velocity tube, also known as "Anuba", is generally used for velocity measurement in circular pipes. It is to insert a thin tube into the inlet of the variable air volume device, divide the measured section into several areas, and open a small hole on the thin tube along the center of each area as a measuring point. These small holes face the direction of airflow, so they are full pressure measuring holes. In addition, one or more small holes are opened in the backflow direction of another thin pipe that is close to the front pipe and has the same pipe diameter as a static pressure measuring hole.

The total pressure measured by the uniform velocity pipe is the average value of the total pressure of the airflow on the pipe section, so the average flow rate is measured, and the volume flow through the cross-sectional area can be obtained by multiplying the average flow rate by the flow cross-sectional area of the pipe.

Pitot tube wind speed sensor is made of aluminum alloy, copper or stainless steel tube. The smaller the outer diameter, the less interference to the airflow and the higher the measurement accuracy. In general, the total area of the full pressure measuring holes should be less than 3% of the total area of the pressure measuring tube. In order to ensure that the sensor has sufficient stiffness, the ratio of the outer diameter of the piezometric tube to the inner diameter of the pipe is generally between 0.04 and 0.09, and the diameter of the full pressure measuring hole on the piezometric tube should be 0.2 to 0.3 times the inner diameter of the piezometric tube, and Should be between 0.5-1.5mm. The position and number of openings on the pressure measuring tube should be determined according to the airflow distribution and control accuracy of the variable air volume terminal device.

For the standard pitot tube, take the air density ρ=1.2kg/m ³ , the magnification factor of the pitot tube F=0.97, and when the wind speed is 1m/s, the measured dynamic pressure value is 0.582Pa. To convert such a small differential pressure signal into an electrical signal with a certain accuracy, an expensive micro differential pressure sensor is required. Therefore, each plant has adopted a different differential pressure output amplification technology. For example, the amplification factor of the sensor is F=3, the assumed measurement range is 0-200Pa, the measurement accuracy is 3% of the full range, the error value is ±6Pa, and the converted wind speed is ±1.8m/s, that is, for an amplification factor of 3 The wind speed sensor of 1.8m/s is meaningless. Similarly, for the wind speed sensor with an amplification factor of 3, a measurement range of 0-400Pa, and a measurement accuracy of 3% of the full range, the error value is ±12Pa. When the measured wind speed is lower than 2.58m/s, the measured Signals don't make sense.

The measurement range of the pitot tube wind speed sensor is 0<△P<400Pa, and the design wind speed can maintain proper measurement accuracy within the range of 3-16m/s wind speed.

As for the current control accuracy of the existing pylon tube, it does not have anti-bias flow (that is, spoiler), which makes the detection result inaccurate, and the current length of the pylon tube can only be customized. The preparation has poor flexibility. Therefore, an improved technology is urgently needed to solve this problem existing in the prior art.

Utility model content

The purpose of the utility model is to provide a Pitot tube sensor for a variable air volume valve. The two ends of the pipe body are respectively provided with a clamping plate and a clamping groove, which can realize the continuous combination of a plurality of pipe bodies and realize the adjustment control of the length. The upper end sealing ring groove and the lower end sealing ring groove are respectively opened at both ends of the dynamic pressure inner pipe and the static pressure inner pipe, so that when the pipe body is connected, a sealing ring is arranged at the connection of the pipe body to realize the sealing of the connection and avoid the occurrence of test results. Error, the pipe body is tangent to the fluid flow direction, the front-end sensing dynamic pressure hole and the rear-end sensing dynamic pressure hole correspond one-to-one, and the corresponding front-end sensing dynamic pressure hole and the rear-end sensing dynamic pressure hole are located on the same axis In order to ensure the accuracy of the test results, there are partition flanges on both sides of the pipe body, and the connection between the partition flange and the pipe body is an arc surface, which can avoid the interference of the pitot tube to the measured fluid. It ensures the control accuracy of the pitot tube and the stability of the fluid. In the case of stable airflow, the amplification factor of the pitot tube is less than F=3, the measurement accuracy is 3% of the full scale, and the measurement accuracy is increased by 2%. The error value is ±3Pa, which is more effective. The precise control of the air-conditioning system can be realized to solve the problems raised in the above background technology.

In order to achieve the above purpose, the present utility model provides the following technical solutions: a Pitot tube sensor for a variable air volume valve, comprising a pipe body, a dynamic pressure inner pipe, a static pressure inner pipe, a front-end sensing dynamic pressure hole, and a rear-end sensing dynamic pressure hole;

The pipe body, the two sides of the pipe body are respectively provided with partition flanges, one end of the pipe body is in a concave shape, and the pipe body is located at the two sides of the concave shape. The other end of the body is a convex structure, and the pipe body is respectively provided with a clamping plate on both sides of the convex structure. The pipe body is located in one end of the concave-shaped structure and has screw holes respectively in the partition flanges on both sides, and the screw holes located in the partition flanges on both sides of the pipe body are communicated with the clamping groove;

a dynamic pressure inner pipe, the dynamic pressure inner pipe runs through the inner upper end of the pipe body, and the pipe body is located at both ends of the dynamic pressure inner pipe with upper end sealing ring grooves respectively;

a static pressure inner pipe, the static pressure inner pipe penetrates through the inner lower end of the pipe body, and the pipe body is located at both ends of the static pressure inner pipe with lower end sealing ring grooves respectively;

front-end sensing dynamic pressure holes, there are several front-end sensing dynamic pressure holes, the front-end sensing dynamic pressure holes are arranged on the upper surface of the pipe body, and the front-end sensing dynamic pressure holes are communicated with the dynamic pressure inner pipe;

The rear end sensing dynamic pressure hole, there are several rear end sensing dynamic pressure holes, the rear end sensing dynamic pressure hole is arranged on the lower surface of the pipe body, the rear end sensing dynamic pressure hole and the static pressure inside The tubes are connected.

Preferably, the present invention provides a Pitot tube sensor for a variable air volume valve, wherein the pipe body is provided with screw holes on the outside of the card plate provided on both sides of the convex-shaped structure, and the screw holes on the outside of the card plate are provided. The holes are matched with the screw holes opened in the partition flange, the clamping plate of one pipe body is connected with the partition flange of the other pipe body, and is fixed by bolts, so that the two pipe bodies are connected to each other.

Preferably, the present invention provides a Pitot sensor for a variable air volume valve, wherein the upper sealing ring groove and the lower sealing ring groove are both longitudinal and tangential semi-circular annular structures, when the two pipe bodies are connected to each other When the two pipe bodies are connected, the upper end sealing ring groove and the two lower end sealing ring grooves form an integral annular sealing ring groove. Completely sealed to avoid air leakage and inaccurate test results.

Preferably, the present invention provides a Pitot sensor for a variable air volume valve, wherein the inner diameters of the dynamic pressure inner pipe, the static pressure inner pipe and the sealing ring are completely the same, and the inner diameters of the dynamic pressure inner pipe or the static pressure inner pipe are completely the same. The inner diameter of the joint is consistent to ensure the accuracy of the test results.

Preferably, the present invention provides a Pitot sensor for a variable air volume valve, wherein the front-end sensing dynamic pressure holes and the rear-end sensing dynamic pressure holes are in one-to-one correspondence, and the corresponding front-end sensing holes are in one-to-one correspondence. The dynamic pressure hole and the rear-end sensing dynamic pressure hole are located on the same axis line, in order to make the detection pressure difference on the same level to ensure the accuracy of the detection results.

Preferably, the utility model provides a pitot tube sensor for a variable air volume valve, wherein the connection between the partition flange and the pipe body is an arc-shaped smooth connection, so that the airflow can slide along the trend, and the detection accuracy is improved. , to avoid too much interference of the pitot tube on the measured fluid.

Preferably, the present utility model provides a Pitot sensor for a variable air volume valve, wherein the radius of the arc surface at the connection between the partition flange and the upper surface of the pipe body is 0.5mm, and the partition flange and the upper surface of the pipe body have a radius of 0.5mm. The radius of the arc surface at the connection on both sides of the lower end of the pipe body is 3 mm.

Compared with the prior art, the beneficial effects of the present utility model are:

(1) The two ends of the pipe body are respectively provided with a clamping plate and a clamping groove, which can realize the continuous combination of multiple pipe bodies and realize the adjustment and control of the length.

(2) The pipe body is located at the two ends of the dynamic pressure inner pipe and the static pressure inner pipe, respectively with an upper end sealing ring groove and a lower end sealing ring groove, so that when the pipe body is connected, a sealing ring is arranged at the connection of the pipe body to realize the sealing of the connection. Sealed to avoid errors in test results.

(3) The pipe body is tangent to the fluid flow direction, the front-end sensing dynamic pressure hole and the rear-end sensing dynamic pressure hole correspond one-to-one, and the corresponding front-end sensing dynamic pressure hole and the rear-end sensing dynamic pressure hole are located in the same On the shaft core line to ensure the accuracy of the test results.

(4) There are partition flanges on both sides of the pipe body, and the connection between the partition flange and the pipe body is an arc surface, which can avoid the excessive interference of the pitot tube to the measured fluid, and ensure the control accuracy of the pitot tube. Fluid stability, in the case of stable airflow, the amplification factor of the pitot tube is <F=3, the measurement accuracy is 3% of the full scale, and the measurement accuracy is increased by 2%, and the error value is ±3Pa, which is more effective to achieve precise control of the air conditioning system.

Description of drawings

Fig. 1 is the top view structure schematic diagram of the present utility model;

Fig. 2 is a schematic view of the cross-sectional structure at A-A in Fig. 1;

Fig. 3 is the left side view structure schematic diagram of the present utility model;

Fig. 4 is the right side view structure schematic diagram of the present utility model;

Figure 5 is a schematic diagram of the radian of the connection between the partition flange and the pipe body.

In the figure: pipe body 1, dynamic pressure inner pipe 2, static pressure inner pipe 3, front-end sensing dynamic pressure hole 4, rear-end sensing dynamic pressure hole 5, partition flange 6, clamping plate 7, upper sealing ring groove 8 , Lower end sealing ring groove 9.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

1-5, the present utility model provides a technical solution: a Pitot tube sensor for a variable air volume valve, comprising a pipe body 1, a dynamic pressure inner pipe 2, a static pressure inner pipe 3, and a front-end sensing dynamic pressure The hole 4 and the rear end sensing dynamic pressure hole 5; the two sides of the pipe body 1 are respectively provided with partition flanges 6, one end of the pipe body 1 is a concave shape structure, and the pipe body 1 is located in the partition flanges 6 on both sides of the concave one end respectively. A card slot is provided, the other end of the pipe body 1 is a convex shape structure, and the pipe body 1 is located on both sides of the convex shape structure with a card plate 7 respectively, and the two sides of the card plate 7 and one end of the concave shape structure of the pipe body 1 are in the partition flange 6 The card slot of the pipe body 1 is located on the outside of the card plate 7 provided on both sides of the convex structure, and there are screw holes, and the screw holes on the outside of the card plate 7 are matched with the screw holes opened in the partition flange 6. 1. There are screw holes in the partition flanges 6 on both sides of one end of the concave structure. The screw holes in the partition flanges 6 on both sides of the pipe body 1 are communicated with the card grooves. The connection between the partition flanges 6 and the pipe body 1 is: The arc is smoothly connected, the radius of the arc surface at the connection between the partition flange 6 and the upper surface of the pipe body 1 is 0.5mm, and the radius of the arc surface at the connection between the partition flange 6 and the lower end of the pipe body 1 on both sides is 3mm; The dynamic pressure inner pipe 2 runs through the inner upper end of the pipe body 1, and the pipe body 1 is located at both ends of the dynamic pressure inner pipe 2 with upper end sealing ring grooves 8 respectively; the static pressure inner pipe 3 runs through the inner lower end of the pipe body 1, and the pipe body 1 The two ends of the static pressure inner tube 3 are respectively provided with lower sealing ring grooves 9. The upper sealing ring groove 8 and the lower sealing ring groove 9 are both longitudinal and tangential semi-circular annular structures. When the two pipe bodies 1 are connected to each other, the two The upper end sealing ring groove 8 and the two lower end sealing ring grooves 9 connected with each tube body 1 form an integral annular sealing ring groove, and a sealing ring is arranged in the integral annular sealing ring groove. The inner diameter of the tube 3 and the sealing ring are exactly the same; there are several front-end sensing dynamic pressure holes 4 , the front-end sensing dynamic pressure hole 4 is arranged on the upper surface of the tube body 1 , and the front-end sensing dynamic pressure hole 4 is connected with the dynamic pressure inner tube 2 There are several rear-end sensing dynamic pressure holes 5, the rear-end sensing dynamic pressure hole 5 is arranged on the lower surface of the pipe body 1, the rear-end sensing dynamic pressure hole 5 is communicated with the static pressure inner pipe 3, and the front-end sensing The dynamic pressure hole 4 and the rear end sensing dynamic pressure hole 5 are in one-to-one correspondence, and the corresponding front end sensing dynamic pressure hole 4 and the rear end sensing dynamic pressure hole 5 are located on the same axis.

Installation method and principle of use: connect one end of the convex structure of the first pipe body 1 to one end of the concave structure of the second pipe body 1, and insert the card plate 7 of the first pipe body 1 into the second pipe body slightly. 1, and then set seals in the upper sealing ring groove 8 and the lower sealing ring groove 9 at the connection between the dynamic pressure inner pipe 2 and the static pressure inner pipe 3 of the first pipe body 1 and the second pipe body 1. Then push each other to make the clamping plate 7 of the first pipe body 1 completely inserted into the clamping groove of the second pipe body 1. At this time, the sealing ring is completely set in the upper sealing ring groove 8 and the lower sealing ring groove 9 Inside, a complete dynamic pressure inner pipe 2 and a complete static pressure inner pipe 3 are formed inside the pipe body 1. Finally, screw the small screws into the screw holes of the partition flange 6 and then continue to screw them into the screw holes on the side of the card plate 7. , so that the first tube body 1 and the second tube body 1 are completely connected, and according to the actual required length, multiple tube bodies 1 are connected by the above method to complete the splicing, and the differential pressure sensor is connected to the dynamic pressure inner tube 2 respectively. And one end of the static pressure inner pipe 3, when in use, the pipe body 1 is opened with a front-end sensing dynamic pressure hole 4 and one end faces the airflow direction, so that the front-end sensing dynamic pressure hole 4 is perpendicular to the fluid flow direction, and the rear end senses the dynamic pressure. The pressure hole 5 is facing away from the fluid flow direction, and the pitot tube detects the flow rate according to the pressure difference caused by the fluid flow, so as to understand the flow law of the air flow, and the volume flow of the air flowing through the variable air volume terminal device can also be calculated through calculation, so as to realize the control of each air volume. The air supply volume of each terminal device and even the entire air conditioning system can be effectively controlled. The structure of the utility model is reasonable. The two ends of the pipe body 1 are respectively provided with a clamping plate 7 and a clamping groove, which can realize the continuous combination of a plurality of pipe bodies 1 and realize the adjustment of the length. Control, the pipe body 1 is located at the two ends of the dynamic pressure inner pipe 2 and the static pressure inner pipe 3 respectively with an upper end sealing ring groove 8 and a lower end sealing ring groove 9, so that when the pipe body 1 is connected, a seal is provided at the connection of the pipe body 1. The pipe body 1 is tangent to the fluid flow direction, the front-end sensing dynamic pressure hole and the rear-end sensing dynamic pressure hole correspond one-to-one, and the corresponding front-end sensing dynamic pressure The pressure hole and the rear-end sensing dynamic pressure hole are located on the same axis line to ensure the accuracy of the detection results. The two sides of the pipe body 1 are respectively provided with partition flanges 6, and the connection between the partition flange 6 and the pipe body 1 They are all arc-shaped surfaces, which can avoid the excessive interference of the pitot tube to the measured fluid, and ensure the control accuracy and fluid stability of the pitot tube. The 3% of the range is increased by 2%, and the error value is ±3Pa, which can more effectively realize the precise control of the air conditioning system.

What is not described in detail in the present invention is the well-known technology of those skilled in the art.

Finally, it should be noted that: the above specific embodiments are only used to illustrate the technical solutions of the present utility model rather than limitations. Although the present utility model has been described in detail with reference to the embodiments, those of ordinary skill in the art should The technical solutions can be modified and equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be included in the scope of the claims of the present invention.

Claims (7)

1. A pitot tube sensor for a variable air volume valve characterized by: comprises a pipe body (1), a dynamic pressure inner pipe (2), a static pressure inner pipe (3), a front end dynamic pressure sensing hole (4) and a rear end dynamic pressure sensing hole (5);

the pipe comprises a pipe body (1), partition flanges (6) are respectively arranged on two sides of the pipe body (1), one end of the pipe body (1) is of a concave structure, clamping grooves are respectively formed in the partition flanges (6) on two sides of one end of the pipe body (1) in the concave shape, the other end of the pipe body (1) is of a convex structure, clamping plates (7) are respectively arranged on two sides of the pipe body (1) in the convex structure, the clamping plates (7) are matched with the clamping grooves in the partition flanges (6) on two sides of one end of the concave structure of the pipe body (1), screw holes are respectively formed in the partition flanges (6) on two sides of one end of the pipe body (1) in the concave structure, and the screw holes in the partition flanges (6) on two sides of the pipe body (;

the dynamic pressure inner pipe (2) penetrates through the upper end inside the pipe body (1), and upper end sealing ring grooves (8) are respectively formed in two ends, located on the dynamic pressure inner pipe (2), of the pipe body (1);

the static pressure inner pipe (3), the static pressure inner pipe (3) penetrates through the lower end of the inside of the pipe body (1), and lower end sealing ring grooves (9) are respectively formed in the two ends, located on the static pressure inner pipe (3), of the pipe body (1);

the front end dynamic pressure sensing holes (4) are formed, a plurality of front end dynamic pressure sensing holes (4) are formed in the front end dynamic pressure sensing holes, the front end dynamic pressure sensing holes (4) are formed in the upper surface of the pipe body (1), and the front end dynamic pressure sensing holes (4) are communicated with the dynamic pressure inner pipe (2);

the rear end sensing dynamic pressure hole (5) is provided with a plurality of rear end sensing dynamic pressure holes (5), the rear end sensing dynamic pressure holes (5) are formed in the lower surface of the pipe body (1), and the rear end sensing dynamic pressure holes (5) are communicated with the static pressure inner pipe (3).

2. A pitot tube sensor for a variable air volume valve according to claim 1 wherein: the pipe body (1) is provided with screw holes at the outer sides of clamping plates (7) arranged at the two sides of the convex-shaped structure, and the screw holes at the outer sides of the clamping plates (7) are matched with screw holes formed in the partition flanges (6).

3. A pitot tube sensor for a variable air volume valve according to claim 1 wherein: the upper end sealing ring groove (8) and the lower end sealing ring groove (9) are both longitudinal and tangential semi-circular structures, when the two pipe bodies (1) are connected with each other, the two upper end sealing ring grooves (8) and the two lower end sealing ring grooves (9) which are connected with the pipe bodies (1) form an integral annular sealing ring groove, and a sealing ring is arranged in the integral annular sealing ring groove.

4. A pitot tube sensor for a variable air volume valve according to claim 1 wherein: the inner diameters of the dynamic pressure inner pipe (2), the static pressure inner pipe (3) and the sealing ring are completely consistent.

5. A pitot tube sensor for a variable air volume valve according to claim 1 wherein: the front end sensing dynamic pressure holes (4) and the rear end sensing dynamic pressure holes (5) are in one-to-one correspondence, and the corresponding front end sensing dynamic pressure holes (4) and the corresponding rear end sensing dynamic pressure holes (5) are located on the same axial centerline.

6. A pitot tube sensor for a variable air volume valve according to claim 1 wherein: the connection part of the partition flange (6) and the pipe body (1) is in arc-shaped smooth connection.

7. A pitot tube sensor for a variable air volume valve according to claim 1 wherein: the radius of the arc-shaped surface at the joint of the partition flange (6) and the upper surface of the pipe body (1) is 0.5mm, and the radius of the arc-shaped surface at the joint of the partition flange (6) and the two sides of the lower end of the pipe body (1) is 3 mm.

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