Ventilator flow measuring assembly

Abstract

A ventilator flow measuring assembly comprises an air inlet assembly arranged on a ventilator, one end of an air cavity in the middle of the air inlet assembly is an inlet end connected with an external pipeline, the other end of the air cavity in the middle of the air inlet assembly is a throat end close to an impeller, and the inlet end and the throat end are each provided with a static pressure measuring nozzle set communicated with the air cavity and used for measuring the internal pressure of the air cavity. Each of the static pressure measuring nozzle groups at the inlet end and the throat end comprises at least two static pressure measuring nozzles, the static pressure measuring nozzles of the same static pressure measuring nozzle group are distributed around the central axis of the air cavity at equal angles on the cross section of the air cavity, and the inner side ends of the static pressure measuring nozzles are flush with the inner wall of the air cavity; the outer side ends of the static pressure measuring nozzles of the same static pressure measuring nozzle group are communicated through an outer connecting pipe, and a pressure tapping pipe communicated with an inner cavity of the outer connecting pipe is arranged on the outer connecting pipe. The ventilator flow measurement assembly is directly arranged on the ventilator, installation is very convenient, meanwhile, the measurement position is slightly affected by an external pipe network, and the measurement value is stable and accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of fan detection, in particular to a fan flow measurement assembly. Background Technique

[0002] The aerodynamic performance test of the fan is divided into laboratory performance test and on-site performance test. The specific test methods respectively follow the regulations of the standards of "GB / T 1236-2017 Performance Test of Industrial Fans with Standardized Air Ducts" and "GB / T 10178-2006 On-site Performance Test of Industrial Fans"; this standard strictly stipulates the position of the flow measurement points and the calculation method of the flow rate when the fan is performing the performance test. At present, in the standard of "GB / T 1236-2017 Performance Test of Industrial Fans with Standardized Air Ducts", the imported collector or the Pitot tube traversing method is mostly used for flow collection. In the standard of "GB / T 10178-2006 On-site Performance Test of Industrial Fans", since the fan has been installed on-site and the corresponding pipelines have been connected, only the Pitot tube traversing method is suitable for flow measurement. When the above flow measurement methods are used for on-site aerodynamic performance test of the installed fan due to actual needs, the following disadvantages exist:

[0003] 1. When there are pipelines connected to both the inlet and outlet of the fan, the inlet collector method for measuring the flow rate cannot be installed due to the influence of the on-site pipeline; if the pipeline is removed for testing, the resistance of the system pipe network will be changed, and the aerodynamic parameters of the fan operating point cannot be effectively obtained. Based on the above two reasons, this method is not suitable for on-site testing.

[0004] 2. The principle of the Pitot tube traversing method for measuring the flow rate is to measure the average dynamic pressure of the cross-section with the Pitot tube at the measurement cross-section. This dynamic pressure is used to calculate the average wind speed, and finally the cross-sectional air volume is obtained by calculating the product of the average wind speed and the measurement cross-sectional area; the key to this method lies in accurately measuring the average dynamic pressure of the cross-section, because the dynamic pressure value is greatly affected by the measurement point position, pipeline shape, and pipeline length. Therefore, the applicability of this method for measuring the flow rate is not strong and cannot meet the test requirements of all installation forms. Content of the Utility Model

[0005] The purpose of the utility model is to provide a fan flow measurement assembly, which is directly set on the fan, very convenient to install, and at the same time, the measurement position is less affected by the external pipe network, and the measurement value is stable and accurate.

[0006] The technical solution adopted by the utility model is: a fan flow measurement assembly, including an air inlet assembly set on the fan. One end of the air chamber in the middle of the air inlet assembly is the inlet end connecting the external pipeline, and the other end is the throat end close to the impeller. The inlet end and the throat end are respectively provided with a static pressure measuring nozzle group that communicates with the air chamber and is used for measuring the internal pressure of the air chamber;

[0007] The static pressure nozzles at the inlet end and the throat end both include no less than two static pressure nozzles. The static pressure nozzles in the same static pressure nozzle group are evenly distributed around the central axis on the cross-section of the air chamber, and the inner ends of the static pressure nozzles are flush with the inner wall of the air chamber.

[0008] The outer ends of the static pressure nozzles in the same static pressure nozzle group are connected through an outer connecting pipe, and a pressure tapping pipe communicating with its inner cavity is provided on the outer connecting pipe.

[0009] As a preferred solution, the cross-section of the air chamber is circular.

[0010] As a preferred solution, the static pressure nozzles in the same group are of equal length.

[0011] As a preferred solution, the outer connecting pipe is integrally annular, and interfaces corresponding one by one to the static pressure nozzles and the pressure tapping pipes are distributed on the side surface.

[0012] As a preferred solution, the inner diameter of the air chamber tapers from the inlet end to the throat end.

[0013] As a preferred solution, flanges are respectively provided at both ends of the air inlet assembly.

[0014] As a preferred solution, rib plates are arranged on the outer wall of the air inlet assembly, and the rib plates are connected to the flanges at both ends of the air inlet assembly.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] 1. By adopting the differential pressure method, the static pressure nozzle group is arranged on the air inlet assembly and directly connected to the ventilator, so that the flow rate of the pipeline where the ventilator is located can be directly detected under the operating state.

[0017] 2. Since the air inlet assembly is a part of the ventilator, the shape, length of the air chamber, and the position of the air chamber relative to the ventilator are fixed, and the influence during detection is small, so it has a wide applicability in flow rate detection.

[0018] 3. The cross-section of the air chamber is designed to be circular. By connecting multiple static pressure nozzles through a pressure tapping pipe, the multiple static pressure nozzles are annularly distributed, and the average pressure of the measured cross-section can be measured, and the fluctuation of the detection value is small.

[0019] The inner ends of the static pressure nozzles are flush with the inner wall of the air chamber, without causing obstruction to the inside of the air chamber, and there is no obvious change in the air flow at the detection position, so the detection result is more real and effective.

[0020] 4. The air chamber of the air inlet assembly is designed to be a tapered type. On the one hand, it is used to connect an external pipeline with a larger diameter. On the other hand, when the diameter of the air chamber tapers, the inner ends of the static pressure nozzles can be closer to the center of the air chamber without extending into the air chamber, and the results measured by the static pressure nozzles are more comprehensive. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is an isometric schematic view of the present invention;

[0023] Figure 2 is an axial sectional schematic view of the present invention.

[0024] Reference numerals: 1, air inlet assembly; 2, air cavity; 3, inlet end; 4, throat end; 5, static pressure measuring nozzle; 6, outer connecting pipe; 7, pressure taking pipe; 8, flange; 9, rib plate. Detailed Description of the Embodiments

[0025] Hereinafter, the present invention will be specifically described by way of exemplary embodiments. However, it should be understood that, without further description, the elements, structures, and features in one embodiment can also be beneficially combined into other embodiments.

[0026] It should be noted that: unless otherwise defined, the technical terms or scientific terms used herein should have the ordinary meaning understood by those of ordinary skill in the art to which the present invention belongs. The words such as "a", "an", or "the" used in the specification and claims of the present patent application do not express a limitation of quantity, but rather indicate the existence of at least one; the "first", "second", and "third" used herein should not be regarded as a limitation on the order of components, but only for distinguishing different components; the words such as "comprising" or "including" indicate that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0027] In order to more clearly describe the specific structural composition of the flow measurement assembly of the ventilator, in combination with the attached Figure 1-2 describe this embodiment:

[0028] Such as Figure 1 and Figure 2As shown in the figure, a flow measurement component for a ventilator includes an air inlet component 1 disposed on the ventilator. One end of the air chamber 2 in the middle of the air inlet component 1 is an inlet end 3 connected to an external pipeline, and the other end is a throat end 4 close to the impeller. Static pressure measuring nozzle groups that communicate with the air chamber 2 and are used to measure the internal pressure of the air chamber 2 are respectively provided at the inlet end 3 and the throat end 4; the static pressure measuring nozzle groups at the inlet end 3 and the throat end 4 both include not less than two static pressure measuring nozzles 5. The static pressure measuring nozzles 5 of the same static pressure measuring nozzle group are equally angularly distributed around the central axis of the air chamber 2 (this central axis is along the axial direction of the air chamber 2) on the cross-section of the air chamber 2, and the inner ends of the static pressure measuring nozzles 5 are flush with the inner wall of the air chamber 2;

[0029] Two groups of static pressure measuring nozzle groups are respectively provided at the inlet end 3 and the throat end 4 of the air inlet component 1 to measure the upstream and downstream pressure differences of the air chamber 2 during the actual operation of the fan. According to the principle of energy conservation in fluid mechanics, the static pressure and flow velocity will be mutually converted when the fluid passes through a convergent variable-diameter pipe. Therefore, the change in dynamic pressure can be indirectly obtained by measuring the static pressure difference between the upstream and downstream of the air inlet component 1, and the flow velocity can be calculated, thereby obtaining the air volume passing through this section. The calculation formula is as follows:

[0030]

[0031] In the formula, q - mass flow rate [kg / s], α - flow coefficient, F0 - throat area [㎡], ρ - gas density [kg / m 3 , ΔP - pressure difference between the inlet and the throat, β - orifice ratio. The flow coefficient is calibrated in the laboratory in advance, and F0 and β can be measured and calculated. After the two groups of static pressure measuring nozzle groups measure the pressures at their respective positions, ΔP is calculated. The diameters of the inlet end and the throat end can be directly measured, and the ratio of the diameter of the throat end to the diameter of the inlet end is the orifice ratio β. After substituting into the formula, the gas flow rate under the corresponding pressure difference is calculated.

[0032] Since the air inlet component 1 is a part of the ventilator, the shape, length of the air chamber 2, and the position of the air chamber 2 relative to the ventilator are all fixed, and the influence during detection is small, so it has a relatively wide applicability in flow detection.

[0033] The outer ends of the static pressure measuring nozzles 5 of the same static pressure measuring nozzle group are connected through an external connecting pipe 6, and a pressure tapping pipe 7 communicating with its inner cavity is provided on the external connecting pipe 6. The end of the pressure tapping pipe far from the external connecting pipe 6 is connected to a pressure sensor to take the air pressure at each position through two pressure sensors. The cross-section of the air chamber 2 is designed as a circle. By connecting multiple static pressure measuring nozzles through one pressure tapping pipe 7, the multiple static pressure measuring nozzles 5 are annularly distributed, and the average pressure of the measured cross-section can be measured, and the fluctuation of the detection value is small; the inner ends of the static pressure measuring nozzles 5 are flush with the inner wall of the air chamber 2, without causing obstruction to the inside of the air chamber 2, and there is no obvious change in the air flow at the detection position, and the detection result is more real and effective.

[0034] Specifically, the static pressure nozzles 5 in the same static pressure nozzle group are of equal length, the outer connecting pipe 6 is integrally annular, and interfaces corresponding to the static pressure nozzles 5 and the pressure tapping pipes 7 are distributed on the side surface.

[0035] The cross-section of the air chamber 2 is designed to be circular, so that the lengths from the inner ends of the static pressure nozzles 5 to the center of the air chamber 2 are equal, making the air pressure of the static pressure nozzles 5 in the same static pressure nozzle group balanced and reducing fluctuations.

[0036] The inner diameter of the air chamber 2 tapers from the inlet end 3 to the throat end 4. The air chamber 2 of the air inlet assembly 1 is designed to be tapered. On the one hand, it is used to connect an external pipe with a larger diameter. On the other hand, when the diameter of the air chamber 2 tapers, the inner ends of the static pressure nozzles 5 can be closer to the center of the air chamber 2 without extending into the air chamber 2, making the results measured by the static pressure nozzles 5 more comprehensive.

[0037] Specifically, flanges 8 are respectively provided at both ends of the air inlet assembly 1 for connecting an external pipe and other parts of the ventilator housing. Rib plates 9 are arranged on the outer wall of the air inlet assembly 1, and the rib plates 9 are connected to the flanges 8 at both ends of the air inlet assembly 1, achieving the effect of enhancing the structural stability.

[0038] The parts not detailed in this embodiment are prior art.

[0039] It should be noted that although the present invention has been described through the above embodiments, the present invention can also have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope protected by the appended claims of the present invention and their equivalents.

Claims

1. A flow measurement component for a ventilator, characterized in that: It includes an air inlet assembly (1) arranged on a ventilator. One end of an air chamber (2) in the middle of the air inlet assembly (1) is an inlet end (3) connected to an external pipeline, and the other end is a throat end (4) close to the ventilator impeller. Static pressure manometer nozzle groups for communicating with the air chamber (2) and measuring the internal pressure in the air chamber are respectively arranged at the inlet end (3) and the throat end (4). The static pressure manometer nozzle groups at the inlet end (3) and the throat end (4) both include no less than two static pressure manometer nozzles (5). The static pressure manometer nozzles (5) in the same static pressure manometer nozzle group are equally angularly distributed around the central axis on the cross-section of the air chamber (2), and the inner ends of the static pressure manometer nozzles (5) are flush with the inner wall of the air chamber (2). The outer ends of the static pressure manometer nozzles (5) in the same static pressure manometer nozzle group are communicated through an external connecting pipe (6), and a pressure tapping pipe (7) communicating with its inner cavity is arranged on the external connecting pipe (6).

2. The flow measurement assembly of a ventilator according to claim 1, wherein: The cross-section of the air chamber (2) is circular.

3. The flow measurement component of a ventilator according to claim 2, wherein: The static pressure manometer nozzles (5) in the same static pressure manometer nozzle group are of equal length.

4. The flow measurement assembly of a ventilator according to claim 1, wherein: The external connecting pipe (6) is integrally annular, and interfaces corresponding to the static pressure manometer nozzles (5) and the pressure tapping pipes (7) are distributed on its side surface.

5. The flow measurement assembly of a ventilator according to claim 1, wherein: The inner diameter of the air chamber (2) tapers from the inlet end (3) to the throat end (4).

6. The flow measurement component of a ventilator according to claim 1, characterized in that: Flanges (8) are respectively arranged at both ends of the air inlet assembly (1).

7. The flow measurement component of a ventilator according to claim 6, characterized in that: Reinforcing ribs (9) are arranged on the outer wall of the air inlet assembly (1), and the reinforcing ribs (9) are connected to the flanges (8) at both ends of the air inlet assembly (1).

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