Ventilation pipe resistance coefficient testing device

Abstract

The utility model discloses a ventilation pipe resistance coefficient testing device, and belongs to the field of ventilation systems. The ventilation pipe resistance coefficient testing device comprises a flow equalizing assembly, a first flow equalizing straight pipe, a to-be-tested pipe, a second flow equalizing straight pipe and an air suction assembly. Through the arrangement of the first flow equalizing straight pipe, the second flow equalizing straight pipe and the flow equalizing assembly located at the air inlet of the first flow equalizing straight pipe, the flow distance of gas can be long enough before the gas enters the pipe fitting to be tested, so that the gas flow is more stable and uniform, the influence of the unstable gas flow on the test result is avoided, and the test efficiency is improved. The test holes are arranged on the first flow-equalizing straight pipe and the second flow-equalizing straight pipe which are uniform and stable in air flow distribution, so that the accuracy of the test result of the experimental instrument can be further improved.

Description

Technical Field

[0001] The utility model relates to the field of ventilation systems, in particular to a ventilation pipe resistance coefficient testing device. Background Art

[0002] A pipe network system refers to a system that transports and distributes fluids to relevant equipment or spaces, or collects fluids from various receiving points and transports them to designated points, such as air-conditioning pipe network systems, dust removal pipe network systems, gas supply pipe network systems, chemical plant exhaust pipe network systems, etc.

[0003] Dust removal pipe networks are commonly used in industrial production processes, collecting dust generated during production to prevent ambient air pollution. With the advancement of pipe network engineering technology, the requirements for resistance balance in pipe networks are becoming increasingly stringent. Due to the complex overall structure of dust removal pipe networks, the numerous dust sources, and the long pipelines, the primary method for obtaining the resistance coefficient of ventilation pipes currently relies on computer numerical simulation to obtain simulation data.

[0004] However, during the numerical simulation process, the accuracy of the obtained ventilation pipe resistance coefficient is low due to factors such as model selection, boundary condition setting, and grid discretization. Utility Model Content

[0005] The present invention provides a device for testing the resistance coefficient of ventilation pipes. This device can solve the problem of low accuracy of the resistance coefficient of ventilation pipes obtained in the prior art. The technical solution is as follows:

[0006] The ventilation pipe resistance coefficient testing device includes: a flow balancing component, a first flow balancing straight pipe, a pipe to be tested, a second flow balancing straight pipe and an air suction component;

[0007] The flow balancing component is connected to the air inlet of the first flow balancing straight pipe;

[0008] The air outlet of the first flow-balancing straight pipe is connected to the air inlet of the pipe to be tested;

[0009] The air outlet of the pipe to be tested is connected to the air inlet of the second flow-balancing straight pipe;

[0010] The air outlet of the second flow-balancing straight pipe is connected to the air suction component;

[0011] Among them, both the first flow balancing straight pipe and the second flow balancing straight pipe have measuring holes, the ratio of the length of the first flow balancing straight pipe to the inner diameter of the air inlet of the pipe to be tested is greater than or equal to eight, and the ratio of the length of the second flow balancing straight pipe to the inner diameter of the air outlet of the pipe to be tested is greater than or equal to eight.

[0012] Optionally, the first flow balancing straight pipe has a plurality of inlet measuring holes, and the ratio of the shortest distance between any one of the inlet measuring holes and the air inlet of the first flow balancing straight pipe to the inner diameter of the air inlet of the pipe to be tested is greater than or equal to four, and the ratio of the shortest distance between any one of the inlet measuring holes and the air outlet of the first flow balancing straight pipe to the inner diameter of the air inlet of the pipe to be tested is greater than or equal to four;

[0013] The second flow balancing straight pipe has multiple outlet measuring holes, and the ratio of the shortest distance between any one of the outlet measuring holes and the air inlet of the second flow balancing straight pipe to the inner diameter of the air outlet of the pipe to be tested is greater than or equal to six.

[0014] Optionally, any one of the first flow balancing straight pipe and the second flow balancing straight pipe is a target flow balancing straight pipe, any one of the inlet measuring hole and the outlet measuring hole is a target measuring hole, and a plurality of the target measuring holes are located on the target flow balancing straight pipe, and a cross-section of the target flow balancing straight pipe in a radial direction of the target flow balancing straight pipe is circular;

[0015] The multiple target measuring holes are arranged along the radial direction of the target flow-sharing straight pipe, and the distance between any two adjacent target measuring holes is equal.

[0016] Optionally, the angle between the shortest connecting line between any two adjacent target measuring holes and the target axis is in the range of 30 degrees to 90 degrees, and the target axis is the axis of the target flow-sharing straight pipe.

[0017] Optionally, any one of the first flow-sharing straight pipe and the second flow-sharing straight pipe is a target flow-sharing straight pipe, any one of the inlet measuring hole and the outlet measuring hole is a target measuring hole, and a plurality of the target measuring holes are located on the target flow-sharing straight pipe, and the cross-section of the target flow-sharing straight pipe in the radial direction of the target flow-sharing straight pipe is rectangular;

[0018] The target flow-sharing straight pipe comprises a target side plate and other side plates except the target side plate, and the area of ​​the target side plate is greater than or equal to the area of ​​the other side plates;

[0019] The multiple target measurement holes are located on the target side plate, and an arrangement direction of the multiple target measurement holes is perpendicular to an extension direction of the target flow-sharing straight pipe.

[0020] Optionally, the distances between any two adjacent target measuring holes are equal, and the shortest distance between any two adjacent target measuring holes is greater than or equal to 80 mm.

[0021] Optionally, the ventilation pipe resistance coefficient testing device further includes: a sealing plug, which is located in the measuring hole.

[0022] Optionally, the air suction assembly includes an air supply duct, an induced draft fan, a gas flow meter and a fan frequency converter;

[0023] The air supply duct is connected to the air outlet of the induced draft fan and the second flow-balancing straight pipe respectively;

[0024] The gas flow meter is installed on the air supply duct;

[0025] The fan frequency converter is electrically connected to the gas flow meter and the induced draft fan respectively.

[0026] Optionally, the flow balancing assembly includes a connected porous plate and a fixing member, the fixing member is respectively connected to the porous plate and the first flow balancing straight pipe, and the porous plate is located at the air inlet of the first flow balancing straight pipe;

[0027] The porous plate has a plurality of circular through holes, the diameter of the circular through holes ranges from 5 mm to 10 mm, and the porosity of the porous plate ranges from 40% to 60%.

[0028] Optionally, the ventilation pipe resistance coefficient testing device further includes three support frames, and the three support frames are respectively located on a side of the first flow-balancing straight pipe, the pipe to be tested, and the second flow-balancing straight pipe close to the ground;

[0029] Any one of the support frames comprises a shock-absorbing pad, a load-bearing frame and a telescopic bracket;

[0030] The shock-absorbing pad is located on a side of the supporting frame facing away from the ground. The telescopic bracket is connected to a side of the supporting frame close to the ground, and the telescopic bracket can be telescoped in a direction perpendicular to the ground.

[0031] The beneficial effects of the technical solution provided by the embodiment of the utility model are:

[0032] Provided is a ventilation duct resistance coefficient testing device comprising a flow balancing component, a first flow balancing straight pipe, a pipe to be tested, a second flow balancing straight pipe and an air suction component. By arranging the first flow balancing straight pipe, the second flow balancing straight pipe and the flow balancing component located at the air inlet of the first flow balancing straight pipe, the gas can have a sufficiently long flow distance before entering the pipe to be tested, thereby making the airflow more stable and uniform, avoiding the influence of unstable airflow on the test results. In addition, by arranging the measuring holes on the first flow balancing straight pipe and the second flow balancing straight pipe where the airflow distribution is uniform and stable, the accuracy of the test results of the experimental instrument can be further improved, and the problem of low accuracy of the ventilation duct resistance coefficient obtained in the related art can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a structural diagram of a ventilation pipe resistance coefficient testing device provided by an embodiment of the present utility model;

[0035] Figure 2 This is a schematic diagram of the position of the measuring holes in a ventilation pipe resistance coefficient testing device provided by an embodiment of the present utility model;

[0036] Figure 3 This is a schematic diagram of the cross-sectional structure of a target flow-sharing straight pipe provided by an embodiment of the present utility model;

[0037] Figure 4 Is a schematic diagram of the cross-sectional structure of another target flow straight pipe provided in an embodiment of the present utility model;

[0038] Figure 5 This is a schematic structural diagram of a current balancing component provided by an embodiment of the present utility model;

[0039] Figure 6 This is a schematic diagram of the structure of a support frame provided by an embodiment of the utility model;

[0040] Figure 7 This is a schematic diagram of the relationship between an elbow resistance coefficient value and the shortest distance between the inlet measuring hole and the air inlet of the first flow-balancing straight pipe provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] Although the present invention can be easily embodied as embodiments of different forms, only some of the specific embodiments are shown in the drawings and will be described in detail in this specification. It should be understood that this description should be regarded as an exemplary illustration of the principles of the present invention and is not intended to limit the present invention to that described herein.

[0043] Thus, a feature indicated in this specification is intended to illustrate one of the features of one embodiment of the present invention, rather than implying that every embodiment of the present invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other, not explicitly described, combinations. Thus, unless otherwise noted, the described combinations are not intended to be limiting.

[0044] In the embodiments shown in the accompanying drawings, directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of various components of the present invention are not absolute but relative. These descriptions are applicable when these components are in the positions shown in the accompanying drawings. If the descriptions of the positions of these components are changed, these directional indications will also change accordingly.

[0045] Please refer to Figure 1 , Figure 1 This is a structural diagram of a ventilation pipe resistance coefficient testing device 10 provided in an embodiment of the present invention. Figure 1 The arrow in the figure indicates the direction of gas flow. The ventilation pipe resistance coefficient testing device 10 may include: a flow balancing component 11, a first flow balancing straight pipe 12, a pipe to be tested 13, a second flow balancing straight pipe 14, and an air suction component 15. The flow balancing component 11, the first flow balancing straight pipe 12, the pipe to be tested 13, the second flow balancing straight pipe 14, and the air suction component 15 can be connected in sequence along the direction of gas flow. The resistance coefficient testing device can be used to test the resistance coefficient of the pipe to be tested 13, which can be a heterogeneous pipe, which can include elbows, valves, etc.

[0046] The flow balancing component 11 can be connected to the air inlet of the first flow balancing straight pipe 12, the air outlet of the first flow balancing straight pipe 12 can be connected to the air inlet of the pipe to be tested 13, and the shape and size of the air outlet of the first flow balancing straight pipe 12 are the same as the shape and size of the air inlet of the pipe to be tested 13; the air outlet of the pipe to be tested 13 is connected to the air inlet of the second flow balancing straight pipe 14, and the shape and size of the air outlet of the pipe to be tested 13 are the same as the shape and size of the air inlet of the second flow balancing straight pipe 14, and the air outlet of the second flow balancing straight pipe 14 is connected to the suction component 15.

[0047] If a flow balancing device is not provided at the air inlet of the first flow balancing straight pipe 12, the gas in the air is more likely to have uneven airflow distribution when it is just sucked into the first flow balancing straight pipe 12. For example, the gas in the first flow balancing straight pipe 12 is mainly concentrated in the middle of the pipe. The uneven airflow distribution in the first flow balancing straight pipe 12 may affect the accuracy of the resistance coefficient test. In the embodiment of the present invention, a flow balancing component 11 is provided at the air inlet of the first flow balancing straight pipe 12 so that the airflow is evenly distributed after entering the first flow balancing straight pipe 12, thereby improving the accuracy of the resistance coefficient test. The first flow balancing straight pipe 12 and the second straight pipe are both straight pipes extending along a straight line without bends or corners. The straight pipe can ensure the stability of the fluid flow inside the pipe.

[0048] Among them, the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14 both have measuring holes (m1 and m2), the ratio of the length of the first flow-equalizing straight pipe 12 to the inner diameter of the air inlet of the pipe 13 to be tested is greater than or equal to eight, and the ratio of the length of the second flow-equalizing straight pipe 14 to the inner diameter of the air outlet of the pipe 13 to be tested is greater than or equal to eight. The test end of the experimental instrument can be extended into the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14 through the measuring holes (m1 and m2) to calculate the resistance coefficient of the pipe 13 to be tested based on the total pressure difference measured through the measuring holes (m1 and m2) in the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14. The purpose of setting the outlet flow-equalizing straight pipe is to reduce the airflow disturbance caused by the elbows and diameter changes in the pipe 13 to be tested, so as to make the airflow more stable and uniform.

[0049] That is, the length of the first flow balancing straight pipe 12, the length of the second flow balancing straight pipe 14, the inner diameter of the air inlet of the pipe to be tested 13, and the inner diameter of the air outlet of the pipe to be tested 13 satisfy the following relationship:

[0050] L1≥8D1;

[0051] L2≥8D2;

[0052] Wherein, L1 is the length of the first flow balancing straight pipe 12, L2 is the length of the second flow balancing straight pipe 14, D1 is the inner diameter value of the air inlet of the pipe 13 to be tested, and D2 is the inner diameter value of the air outlet of the pipe 13 to be tested.

[0053] In the embodiment of the present invention, by providing a first flow-equalizing straight pipe 12 and a second flow-equalizing straight pipe 14 that meet the aforementioned length requirements, the gas can have a sufficiently long flow distance before entering the pipe 13 to be tested, thereby making the airflow more stable and uniform, and preventing unstable airflow from affecting the test results. Furthermore, since the pipe 13 to be tested is a heterogeneous pipe, the gas is more likely to generate vortices when flowing through the pipe 13 to be tested, resulting in uneven airflow. Therefore, the measurement holes (m1 and m2) are arranged on the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14, where the airflow distribution is uniform and stable, which can improve the accuracy of the test results of the experimental instrument.

[0054] To sum up, the embodiment of the present invention provides a ventilation duct resistance coefficient testing device 10 including a flow balancing component 11, a first flow balancing straight pipe 12, a pipe to be tested 13, a second flow balancing straight pipe 14 and an air suction component 15. By setting the first flow balancing straight pipe 12, the second flow balancing straight pipe 14 and the flow balancing component 11 located at the air inlet of the first flow balancing straight pipe 12, the gas can have a sufficiently long flow distance before entering the pipe to be tested 13, so that the airflow is more stable and uniform, avoiding the influence of unstable airflow on the test results, and setting the measuring holes (m1 and m2) on the first flow balancing straight pipe 12 and the second flow balancing straight pipe 14 where the airflow distribution is uniform and stable can further improve the accuracy of the test results of the experimental instrument, and can solve the problem of low accuracy of the ventilation duct resistance coefficient obtained in the related art.

[0055] It should be noted that the shape of the air inlet of the pipe fitting 13 to be tested may include a circle or a rectangle. When the shape of the air inlet of the pipe fitting 13 to be tested is a circle, the inner diameter value D1 of the air inlet of the pipe fitting 13 to be tested is the diameter of the circular air outlet; when the shape of the air inlet of the pipe fitting 13 to be tested is a rectangle, the inner diameter value D1 of the air inlet of the pipe fitting 13 to be tested is the equivalent diameter of the rectangular air inlet. At this time, the inner diameter value D1 of the air inlet of the pipe fitting 13 to be tested satisfies the following relationship: D1=2A1B1 / (A1+B1), where A1 and B1 are the side lengths of the rectangular air inlet.

[0056] Similarly, the shape of the air outlet of the pipe fitting 13 to be tested may include a circle or a rectangle. When the shape of the air outlet of the pipe fitting 13 to be tested is a circle, the inner diameter value D2 of the air outlet of the pipe fitting 13 to be tested is the diameter of the circular air outlet; when the shape of the air outlet of the pipe fitting 13 to be tested is a rectangle, the inner diameter value D2 of the air outlet of the pipe fitting 13 to be tested is the equivalent diameter of the rectangular air outlet. At this time, the inner diameter value D2 of the air outlet of the pipe fitting 13 to be tested satisfies the following relationship: D2=2A2B2 / (A2+B2), where A2 and B2 are the side lengths of the rectangular air outlet.

[0057] In an optional embodiment, the connection methods among the flow balancing component 11, the first flow balancing straight pipe 12, the pipe to be tested 13, the second flow balancing straight pipe 14 and the air suction component 15 can all include flange connections, so that the above-mentioned multiple structures can be freely disassembled and replaced.

[0058] The ventilation duct resistance coefficient testing device 10 may also include a plurality of sealing strips, which may be located at the flange connections of the plurality of structures to ensure the airtightness of the connections of the plurality of structures in the ventilation duct resistance coefficient testing device 10. For example, the air outlet of the first flow-balancing straight pipe 12 may be fixedly connected to a first flange, and the air inlet of the pipe to be tested 13 may be fixedly connected to a second flange, and the sealing strip may be bonded to at least one of the first flange and the second flange to improve the sealing of the flange connection. The material of the sealing strip may include ethylene-vinyl acetate copolymer material, so that the sealing strip has weather resistance, cushioning, sealing and adhesion properties, and can also play a role in sound insulation and shock absorption.

[0059] In an optional embodiment, the material of the pipe fitting 13 to be tested may include metal, plastic, rubber or ceramic, etc., and the type of the pipe fitting 13 to be tested may include elbows, concentric reducers, throttling tubes, valves or expansion joints, etc. The type of the pipe fitting 13 to be tested may include specially processed pipe fittings, such as adding ceramic sheets to the inner wall of the elbow, non-standard concentric reducers or valves with specified openings, etc.

[0060] The ventilation duct resistance coefficient testing device 10 may include first flow-balancing straight pipes 12 and second flow-balancing straight pipes 14 of various specifications and shapes, which are used to match the ducts 13 to be tested of different types or specifications. After determining the shape and size of the air inlet and air outlet of the duct 13 to be tested, matching first flow-balancing straight pipes 12 and second flow-balancing straight pipes 14 can be selected from the various first flow-balancing straight pipes 12 and the various second flow-balancing straight pipes 14 to be connected to the duct 13 to be tested. The air inlet and air outlet of the duct 13 to be tested can both be fixedly connected to flanges so that the duct 13 to be tested and the matching first flow-balancing straight pipes 12 and second flow-balancing straight pipes 14 can be detachably connected.

[0061] Compared with the related art of obtaining the resistance coefficient of ventilation heterogeneous pipe fittings by consulting manuals and performing computer numerical simulations, the embodiment of the utility model determines the resistance coefficient of heterogeneous pipe fittings through experimental testing, which can improve the accuracy of the measurement results.

[0062] Please refer to Figure 2 , Figure 2This is a schematic diagram of the measurement hole positions in a ventilation pipe resistance coefficient testing device 10 provided by an embodiment of the present invention. In an optional embodiment, the first flow-equalizing straight pipe 12 may have multiple inlet measurement holes m1, and the ratio of the shortest distance between any inlet measurement hole m1 and the air inlet of the first flow-equalizing straight pipe 12 to the inner diameter value of the air inlet of the pipe 13 to be tested is greater than or equal to four, and the ratio of the shortest distance between any inlet measurement hole m1 and the air outlet of the first flow-equalizing straight pipe 12 to the inner diameter value of the air inlet of the pipe 13 to be tested is greater than or equal to four; the second flow-equalizing straight pipe 14 has multiple outlet measurement holes m2, and the ratio of the shortest distance between any outlet measurement hole m2 and the air inlet of the second flow-equalizing straight pipe 12 to the inner diameter value of the air outlet of the pipe 13 to be tested is greater than or equal to six.

[0063] That is, the shortest distance between any inlet measuring hole m1 and the air inlet of the first flow-balancing straight pipe 12, the shortest distance between any inlet measuring hole m1 and the air outlet of the first flow-balancing straight pipe 12, the shortest distance between any outlet measuring hole m2 and the air inlet of the second flow-balancing straight pipe 14, the inner diameter value of the air inlet of the pipe to be tested 13, and the inner diameter value of the air outlet of the pipe to be tested 13 satisfy the following relationship:

[0064] C1≥4D1;

[0065] C2≥4D1;

[0066] C3≥6D2;

[0067] Among them, C1 is the shortest distance between any inlet measuring hole m1 and the air inlet of the first flow balancing straight pipe 12, C2 is the shortest distance between any inlet measuring hole m1 and the air outlet of the first flow balancing straight pipe 12, C3 is the shortest distance between any outlet measuring hole m2 and the air inlet of the second flow balancing straight pipe 14, D1 is the inner diameter value of the air inlet of the pipe fitting 13 to be tested, and D2 is the inner diameter value of the air outlet of the pipe fitting 13 to be tested.

[0068] In this way, the inlet measuring hole m1 and the outlet measuring hole m2 can both be located at positions where the airflow is stable, thereby preventing the inlet measuring hole m1 from being affected by the unstable airflow that has just entered the first flow-balancing straight pipe 12 and affecting the test results at the inlet measuring hole m1. It can also prevent the unstable airflow passing through the pipe 13 to be tested from affecting the test results at the outlet measuring hole m2, thereby improving the accuracy of the measurement results.

[0069] Please refer to Figure 3 , Figure 3This is a schematic diagram of the cross-sectional structure of a target flow-equalizing straight pipe 10a provided by an embodiment of the present invention. In an optional embodiment, any one of the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14 is the target flow-equalizing straight pipe 10a, and any one of the inlet measuring hole m1 and the outlet measuring hole m2 is the target measuring hole a3, and multiple target measuring holes a3 are located on the target flow-equalizing straight pipe 10a, and the cross-section of the target flow-equalizing straight pipe 10a in the radial direction of the target flow-equalizing straight pipe 10a is circular; multiple target measuring holes a3 are arranged along the radial direction of the target flow-equalizing straight pipe 10a, and the distance between any two adjacent target measuring holes a3 is equal. That is, any one of the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14 can be a circular pipe, or the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14 can both be circular pipes.

[0070] When the target flow-equalizing straight pipe 10a is a circular pipe, multiple target measuring holes a3 can be located on the same section of the target flow-equalizing straight pipe 10a, which can be a radial section along the target flow-equalizing straight pipe 10a. Tests can be performed at multiple target side holes to improve the accuracy and reliability of the test results.

[0071] In an optional embodiment, the angle α between the shortest connecting line between any two adjacent target measuring holes a3 and the target axis ranges from 30 degrees to 90 degrees, and the target axis is the axis of the target flow-equalizing straight pipe 10a. Exemplarily, the angle α between the shortest connecting line between any two adjacent target measuring holes a3 and the target axis is 30 degrees, 50 degrees, 60 degrees, 80 degrees or 90 degrees. The number of target measuring holes a3 is 3, and 6 measuring points n1 can be set on the shortest connecting line between each target measuring hole a3 and the target axis, for a total of 36 measuring points n1. It should be noted that the shortest connecting line in the embodiment of the present invention is a virtual connecting line, so as to more clearly illustrate the positional relationship of multiple target side holes.

[0072] Please refer to Figure 4 , Figure 4It is a schematic diagram of the cross-sectional structure of another target flow-equalizing straight pipe 10a provided in an embodiment of the present invention. In an optional embodiment, any one of the first flow-equalizing straight pipe 12 and the second flow-equalizing straight pipe 14 is the target flow-equalizing straight pipe 10a, and any one of the inlet measuring hole m1 and the outlet measuring hole m2 is the target measuring hole a3, and multiple target measuring holes a3 are located on the target flow-equalizing straight pipe 10a, and the cross-section of the target flow-equalizing straight pipe 10a in the radial direction of the target flow-equalizing straight pipe 10a is rectangular; the target flow-equalizing straight pipe 10a has a target side plate 10a1 and other side plates except the target side plate 10a1, and the plate surface area of ​​the target side plate 10a1 is greater than or equal to the plate surface area of ​​other side plates; multiple target measuring holes a3 are located on the target side plate 10a1, and the arrangement direction of the multiple target measuring holes a3 is perpendicular to the extension direction of the target flow-equalizing straight pipe 10a. That is, either the first flow-sharing straight pipe 12 or the second flow-sharing straight pipe 14 can be a rectangular pipe, or both the first flow-sharing straight pipe 12 and the second flow-sharing straight pipe 14 can be rectangular pipes. In the radial direction of the target flow-sharing straight pipe 10a, the width of the target side plate 10a1 is greater than or equal to the width of the other side plates.

[0073] When the target flow-sharing straight pipe 10a is a rectangular pipe, multiple target measuring holes a3 can be located on a target side plate 10a1 with a larger width, and testing can be performed at multiple target measuring holes a3 to improve the accuracy and reliability of the test results.

[0074] In an optional real-time mode, the distance between any two adjacent target measurement holes a3 is equal, and the shortest distance between any two adjacent target measurement holes a3 is less than or equal to 80 mm. For example, the shortest distance between any two adjacent target measurement holes a3 is 40 mm, 50 mm, 60 mm, 70 mm, or 80 mm. There are six target measurement holes a3, and eight measurement points n1 can be set at each target measurement hole a3, for a total of 48 measurement points n1.

[0075] In an optional embodiment, the ventilation duct resistance coefficient testing device 10 may further include a sealing plug (not shown), which may be located in the measuring hole. When a measuring hole is temporarily unused, the sealing plug may be placed in the measuring hole to ensure the airtightness of the first and second flow-balancing straight pipes 12, 14. The sealing plug may be a silicone plug, which may be made of silicone resin. Silicone plugs have excellent high-temperature resistance, chemical corrosion resistance, and environmental protection properties, and can maintain their physical properties and elasticity at different ambient temperatures.

[0076] Please refer to Figure 1In an optional embodiment, the air suction assembly 15 may include an air supply duct 151, an induced draft fan 152, a gas flow meter 153 and a fan frequency converter 154; the air supply duct 151 is respectively connected to the induced draft fan 152 and the air outlet of the second flow equalizing straight pipe 14; the gas flow meter 153 is installed on the air supply duct 151; and the fan frequency converter 154 is respectively electrically connected to the gas flow meter 153 and the induced draft fan 152. The induced draft fan 152 includes a centrifugal induced draft fan 152, and the gas flow meter 153 includes a vortex flowmeter. During the experimental test, the flow meter can monitor the gas flow in the air supply duct 151 in real time, and the fan air volume can be adjusted through the fan frequency converter 154 according to the real-time monitored data and the preset reference data, which can save power consumption and achieve accurate control of the air volume, thereby enhancing the reliability of the test results.

[0077] Please refer to Figure 5 , Figure 5 The figure is a schematic diagram of the structure of a flow balancing assembly 11 provided in an embodiment of the present invention. In an optional embodiment, the flow balancing assembly 11 may include a connected porous plate 111 and a fixing member 112, which may be a flange. The fixing member 112 is respectively connected to the porous plate 111 and the first flow balancing straight pipe 12. The porous plate 111 is located at the air inlet of the first flow balancing straight pipe 12. The porous plate 111 has a plurality of circular through holes k1, each with a diameter ranging from 5 mm to 10 mm. The porosity of the porous plate 111 ranges from 40% to 60%.

[0078] The material of the porous plate 111 can include metal, and multiple circular through holes k1 can be arranged in an array. When the gas passes through the circular through holes k1, the airflow flowing out of the circular through holes k1 will form a jet, which can enhance the turbulence effect and make the airflow distribution at the air inlet of the first flow balancing straight pipe 12 more uniform.

[0079] Please refer to Figure 6 , Figure 6 It is a structural schematic diagram of a support frame provided by an embodiment of the present utility model. In an optional embodiment, the ventilation pipe resistance coefficient testing device 10 can also include three support frames, and the three support frames are respectively located on the side of the first flow balancing straight pipe 12, the pipe to be tested 13 and the second flow balancing straight pipe 14 close to the ground. The three support frames can respectively include a first support frame 161, a second support frame 162 and a third support frame 163, wherein the first support frame 161 is in contact with the first flow balancing straight pipe 12, the second support frame 162 is in contact with the pipe to be tested 13, and the third support frame 163 is in contact with the second flow balancing straight pipe 14.

[0080] Any one support frame comprises a shock pad (not shown in the figure), a bearing frame 1611 and a telescopic support 1612; the shock pad is located on the side of the bearing frame 1611 away from the ground, and the shock pad can reduce the vibration generated by the pipe when the system is running; the telescopic support 1612 is connected to the side of the bearing frame 1611 close to the ground, and the telescopic support 1612 can be telescopic in the direction perpendicular to the ground. The material of the bearing frame 1611 and the telescopic support 1612 can comprise a metal square tube. For example, the ratio between the length value of the first support frame 161 in the extension direction of the first flow uniformity straight pipe 12 and the inner diameter value of the first flow uniformity straight pipe 12 is in the range of 2.5-5, and the ratio between the width value of the first support frame 161 perpendicular to the extension direction of the first flow uniformity straight pipe 12 and the inner diameter value of the first flow uniformity straight pipe 12 is in the range of 1.5-2.5. The size of other support frames is similar to the size of the above support frame, and the embodiment of the utility model does not make redundant description here.

[0081] The telescopic support 1612 can comprise a fixed foot t1, a movable foot t2, a height adjuster t3 and a screw rod t4, and the screw rod is located between the fixed foot t1 and the movable foot t2. The fixed foot t1 is welded with the bearing frame 1611, and the height is fixed and cannot be adjusted, and the height of the fixed foot t1 is in the range of 200-250 mm; the height adjuster t3 is installed on the screw rod to adjust the height of the telescopic support 1612, so as to adjust the installation height of the pipe on the support frame, and the adjustment height of the screw rod is in the range of 0-100 mm. The movable foot t2 is detachably connected with the screw rod, so as to adaptively replace the movable foot t2 with different heights when the size difference of different to-be-tested pipes 13 is large, so as to ensure the concentricity of the first flow uniformity straight pipe 12, the to-be-tested pipe 13 and the second flow uniformity straight pipe 14, and the height of the movable foot t2 is in the range of 100-500 mm.

[0082] Since the height between the first flow uniformity straight pipe 12, the to-be-tested pipe 13, the second flow uniformity straight pipe 14 and the air suction assembly 15 may deviate when different types or specifications of to-be-tested pipes 13 are tested, the resistance of the airflow in the first flow uniformity straight pipe 12, the to-be-tested pipe 13, the second flow uniformity straight pipe 14 and the air suction assembly 15 is increased when the airflow flows in the pipes, so that the height of the first flow uniformity straight pipe 12, the to-be-tested pipe 13 and the second flow uniformity straight pipe 14 can be adaptively adjusted by the three support frames, so as to ensure the concentricity of the first flow uniformity straight pipe 12, the to-be-tested pipe 13, the second flow uniformity straight pipe 14 and the air suction assembly 15, that is, the centers of the pipes are kept at the same horizontal height, and the accuracy of the measurement result can be improved.

[0083] In an exemplary embodiment, a method for testing the resistance coefficient of a pipe to be tested 13 using the ventilation pipe resistance coefficient testing device 10 may include the following steps:

[0084] (1) Assemble the straight pipe assembly, connect the flow balancing assembly 11, the first flow balancing straight pipe 12, the second flow balancing straight pipe 14 and the air suction assembly 15 in sequence, and start the air suction assembly 15;

[0085] (2) The three inlet measuring holes m1 of the first equalizing straight pipe 12 and the three outlet measuring holes m2 of the second equalizing straight pipe 14 are used to test the dynamic pressure, static pressure, total pressure, velocity and other values ​​of the airflow respectively, and the average value of the three test results is taken. The resistance coefficient along the straight pipe is calculated based on the test results and the preset formula.

[0086] (3) Assemble the test pipe fittings and install the pipe fitting to be tested 13 between the first flow-sharing straight pipe 12 and the second flow-sharing straight pipe 14;

[0087] (4) The dynamic pressure, static pressure, total pressure, and velocity of the airflow are measured at the three inlet holes m1 of the first flow-balancing straight pipe 12 and the three outlet holes m2 of the second flow-balancing straight pipe 14, respectively. The three test results are averaged. The total pressure difference between the measured inlet hole m1 and the measured outlet hole m2 is the total resistance. Based on the two test results and a preset formula, the longitudinal resistance and local resistance of the pipe 13 to be tested can be calculated, and then the resistance coefficient of the pipe 13 to be tested can be calculated.

[0088] The preset formulas include the following calculation formulas:

[0089] Calculation formula of resistance along the way:

[0090] ;

[0091] The total resistance calculation formula is:

[0092] ;

[0093] The calculation formula of local resistance is:

[0094] ;

[0095] The calculation formula of local resistance coefficient is:

[0096] ;

[0097] Where, 、 respectively represent the frictional resistance and the local resistance of the straight pipe component, with the unit of Pa; λ and ξ represent the frictional resistance coefficient and the local resistance coefficient of the straight pipe component, respectively; L represents the length of the straight pipe section (the first flow uniformizing straight pipe 12 and the second flow uniformizing straight pipe 14), with the unit of m; d represents the inner diameter of the pipe, with the unit of m; represents the air density, with the unit of kg / m3; u represents the air flow rate, with the unit of m / s; P in , P out respectively represent the total pressure on the cross section where the inlet measuring hole m1 is located, with the unit of Pa.

[0098] In an exemplary embodiment, the influence of the shortest distance between the inlet measuring hole m1 and the air inlet of the first flow uniformizing straight pipe 12 on the resistance coefficient of the to-be-tested component can be obtained by arranging the inlet measuring hole m1 at multiple positions of the first flow uniformizing straight pipe 12 with different shortest distances between the inlet measuring hole m1 and the air inlet of the first flow uniformizing straight pipe 12, and calculating the resistance coefficient of the to-be-tested pipe 13 according to the data measured from the multiple inlet measuring holes m1, so as to select a better arrangement position of the inlet measuring hole m1 according to the test result.

[0099] Specifically, the experimental equipment parameters are as follows: the type of the centrifugal induced draft fan 152 in the test air suction component 15 is NO.10-A-18.2D, the rated air volume is 30000 m 3 / h, the rated air pressure is 19374 Pa, the type of the fan frequency converter 154 is G7-450KW, the adjustment frequency range is 0~50HZ, and the precision is 0.1HZ; the type of the gas flow meter 153 is LUGBC-MIK-DN600, the measured flow range is 2000-61000 m 3 / h, the pressure resistance is 1.6Mpa, and the RS485 communication function is provided.

[0100] The opening rate of the perforated plate 111 in the flow uniformizing component 11 is 50%, and the material of the perforated plate 111 is a 3mm-thick carbon steel plate.

[0101] The inner diameter D1 of the first flow uniformizing straight pipe 12 is equal to the inner diameter value D1 of the air inlet of the to-be-tested pipe 13, i.e., D1=211mm, and the length L1 of the first flow uniformizing straight pipe 12 is L1=2800mm. Assuming that the shortest distance C1 between the inlet measuring hole m1 and the air inlet of the first flow uniformizing straight pipe 12, five groups of inlet measuring holes m1 with different distances are arranged on the first flow uniformizing straight pipe 12, and the lengths of C1 are as follows: C 11 =4D1, C 12 =5D1, C 13 =6D1, C 14 =7D1, and C 15 =8D1. Each group of measuring holes includes three measuring holes, and each measuring hole is arranged with 12 measuring points, and a total of 36 measuring points are provided.

[0102] The pipe fitting 13 to be tested may be a 90° elbow with an inner diameter of 211 mm and a ceramic lining. The straight lengths of the elbow inlet and outlet are both 250 mm.

[0103] The inner diameter D2 of the second flow-balancing straight pipe 14 is 211 mm, the length L2 is 2000 mm, and the outlet measuring hole m2 is arranged at a distance of 1500 mm from the air outlet of the elbow.

[0104] The experimental instruments include: intelligent environmental tester, model 6531, used to test pressure and wind speed; L-type pitot tube, coefficient Kp=1.0, used to test pressure; empty box barometer, model DYM3, used to measure atmospheric pressure and air temperature.

[0105] The specific experimental process includes: (1) in the straight pipe assembly state, adjusting the frequency of the centrifugal induced draft fan 152 so that the wind speed in the first flow-equalizing straight pipe 12 is about 21m / s, and conducting experimental tests. According to the test results, the longitudinal resistance coefficient λ of the straight pipe without the elbow installed is calculated to be 0.014.

[0106] (2) After installing the elbow, conduct experimental tests and measure C 11 ~C 15 The total resistance between the inlet measuring hole m1 and the outlet measuring hole m2 are 179.3Pa, 174.8Pa, 170.6Pa, 166.7 and 162.9Pa respectively. The resistance along the straight pipe between the inlet measuring hole m1 and the outlet measuring hole m2 are 61.9Pa, 58.4Pa, 55.0Pa, 51.5Pa and 48.0Pa respectively. The local resistance of the elbow is 117.4Pa, 116.4Pa, 115.6Pa, 115.2Pa and 114.9Pa respectively.

[0107] The calculated local resistance coefficients of the elbows are 0.478, 0.474, 0.471, 0.469 and 0.468 respectively. Figure 7 , Figure 7 This is a schematic diagram of the relationship between the elbow resistance coefficient value and the shortest distance between the inlet measuring hole m1 and the air inlet of the first flow balancing straight pipe 12 provided by an embodiment of the present invention. It can be seen that the elbow resistance coefficient value changes with the distance between the inlet measuring hole m1 and the inlet flow balancing device, and extending the length of the flow balancing straight pipe in front of the inlet measuring hole m1 is beneficial to uniform airflow distribution. Therefore, the ratio of the shortest distance between any inlet measuring hole m1 and the air inlet of the first flow balancing straight pipe 12 to the inner diameter value of the air inlet of the pipe 13 to be measured is greater than or equal to four, which can improve the accuracy of the measurement results.

[0108] To sum up, the embodiment of the present invention provides a ventilation duct resistance coefficient testing device 10 including a flow balancing component 11, a first flow balancing straight pipe 12, a pipe to be tested 13, a second flow balancing straight pipe 14 and an air suction component 15. By setting the first flow balancing straight pipe 12, the second flow balancing straight pipe 14 and the flow balancing component 11 located at the air inlet of the first flow balancing straight pipe 12, the gas can have a sufficiently long flow distance before entering the pipe to be tested 13, so that the airflow is more stable and uniform, avoiding the influence of unstable airflow on the test results, and setting the measuring holes (m1 and m2) on the first flow balancing straight pipe 12 and the second flow balancing straight pipe 14 where the airflow distribution is uniform and stable can further improve the accuracy of the test results of the experimental instrument, and can solve the problem of low accuracy of the ventilation duct resistance coefficient obtained in the related art.

[0109] In addition, the ventilation pipe fitting resistance coefficient testing device 10 can measure the resistance coefficient of the heterogeneous pipe fittings (elbows, concentric reducers, throttling pipes, valves, expansion joints, etc.) of the ventilation pipe network in the dust removal system. The ventilation pipe fitting resistance coefficient testing device 10 has a simple structure and is easy to operate. It can quickly and easily establish a highly reliable database of resistance coefficients of heterogeneous pipe fittings in the dust removal pipe network, seek the best pipe fitting form and the best combination of pipe fittings, and then optimize the pipeline resistance balance to ensure the stable and effective operation of the pipe network system.

[0110] It should be noted that in the accompanying drawings, the sizes of regions may be exaggerated for clarity of illustration. It is also understood that when an element is referred to as being "on" another element, it may be directly on the other element, or there may be an intervening element. Additionally, it is understood that when an element is referred to as being "under" another element, it may be directly under the other element, or there may be one or more intervening elements. Additionally, it is also understood that when an element is referred to as being "between" two elements, it may be the only layer between the two elements, or there may be one or more intervening elements. Similar reference numerals throughout indicate similar elements.

[0111] In the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0112] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A ventilation pipe resistance coefficient testing device, characterized in that: include: A flow balancing component, a first flow balancing straight pipe, a pipe to be tested, a second flow balancing straight pipe and an air suction component; The flow balancing component is connected to the air inlet of the first flow balancing straight pipe; The air outlet of the first flow-balancing straight pipe is connected to the air inlet of the pipe to be tested; The air outlet of the pipe to be tested is connected to the air inlet of the second flow-balancing straight pipe; The air outlet of the second flow-balancing straight pipe is connected to the air suction component; Among them, both the first flow balancing straight pipe and the second flow balancing straight pipe have measuring holes, the ratio of the length of the first flow balancing straight pipe to the inner diameter of the air inlet of the pipe to be tested is greater than or equal to eight, and the ratio of the length of the second flow balancing straight pipe to the inner diameter of the air outlet of the pipe to be tested is greater than or equal to eight.

2. The ventilation pipe resistance coefficient testing device according to claim 1, characterized in that: The first flow balancing straight pipe has a plurality of inlet measuring holes, the ratio of the shortest distance between any one of the inlet measuring holes and the air inlet of the first flow balancing straight pipe to the inner diameter of the air inlet of the pipe to be tested is greater than or equal to four, and the ratio of the shortest distance between any one of the inlet measuring holes and the air outlet of the first flow balancing straight pipe to the inner diameter of the air inlet of the pipe to be tested is greater than or equal to four; The second flow balancing straight pipe has multiple outlet measuring holes, and the ratio of the shortest distance between any one of the outlet measuring holes and the air inlet of the second flow balancing straight pipe to the inner diameter of the air outlet of the pipe to be tested is greater than or equal to six.

3. The ventilation pipe resistance coefficient testing device according to claim 2, characterized in that: Any one of the first flow balancing straight pipe and the second flow balancing straight pipe is a target flow balancing straight pipe, any one of the inlet measuring hole and the outlet measuring hole is a target measuring hole, and a plurality of the target measuring holes are located on the target flow balancing straight pipe, and a cross-section of the target flow balancing straight pipe in a radial direction of the target flow balancing straight pipe is circular; The multiple target measuring holes are arranged along the radial direction of the target flow-sharing straight pipe, and the distance between any two adjacent target measuring holes is equal.

4. The ventilation pipe resistance coefficient testing device according to claim 3, characterized in that: The angle between the shortest connecting line between any two adjacent target measuring holes and the target axis is in the range of 30 degrees to 90 degrees, and the target axis is the axis of the target flow-averaging straight pipe.

5. The ventilation pipe resistance coefficient testing device according to claim 2, characterized in that: Any one of the first flow-sharing straight pipe and the second flow-sharing straight pipe is a target flow-sharing straight pipe, any one of the inlet measuring hole and the outlet measuring hole is a target measuring hole, and a plurality of the target measuring holes are located on the target flow-sharing straight pipe, and a cross-section of the target flow-sharing straight pipe in a radial direction of the target flow-sharing straight pipe is rectangular; The target flow-sharing straight pipe comprises a target side plate and other side plates except the target side plate, and the area of ​​the target side plate is greater than or equal to the area of ​​the other side plates; The multiple target measurement holes are located on the target side plate, and an arrangement direction of the multiple target measurement holes is perpendicular to an extension direction of the target flow-sharing straight pipe.

6. The ventilation pipe resistance coefficient testing device according to claim 5, characterized in that: The distances between any two adjacent target measurement holes are equal, and the shortest distance between any two adjacent target measurement holes is less than or equal to 80 mm.

7. The ventilation pipe resistance coefficient testing device according to claim 1, characterized in that: The ventilation pipe resistance coefficient testing device further includes a sealing plug, which is located in the measuring hole.

8. The ventilation pipe resistance coefficient testing device according to any one of claims 1 to 7, characterized in that: The air suction assembly includes an air supply duct, an induced draft fan, a gas flow meter and a fan frequency converter; The air supply duct is connected to the air outlet of the induced draft fan and the second flow-balancing straight pipe respectively; The gas flow meter is installed on the air supply duct; The fan frequency converter is electrically connected to the gas flow meter and the induced draft fan respectively.

9. The ventilation pipe resistance coefficient testing device according to any one of claims 1 to 7, characterized in that: The flow balancing assembly includes a connected porous plate and a fixing member, the fixing member is respectively connected to the porous plate and the first flow balancing straight pipe, and the porous plate is located at the air inlet of the first flow balancing straight pipe; The porous plate has a plurality of circular through holes, the diameter of the circular through holes ranges from 5 mm to 10 mm, and the porosity of the porous plate ranges from 40% to 60%.

10. The ventilation pipe resistance coefficient testing device according to any one of claims 1 to 7, characterized in that: The ventilation pipe resistance coefficient testing device further includes three support frames, which are respectively located on the first flow-balancing straight pipe, the pipe to be tested, and the second flow-balancing straight pipe on a side close to the ground; Any one of the support frames comprises a shock-absorbing pad, a load-bearing frame and a telescopic bracket; The shock-absorbing pad is located on a side of the supporting frame facing away from the ground. The telescopic bracket is connected to a side of the supporting frame close to the ground, and the telescopic bracket can be telescoped in a direction perpendicular to the ground.

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