Gas rotary flowmeter and gas flow measurement method

Abstract

The embodiment of the present invention discloses a gas impeller flowmeter and a gas flow metering method, which are invented to reduce the pulsation phenomenon caused by the instantaneous flow of the discharge. The gas impeller flowmeter includes more than two metering chambers; a impeller group is respectively provided in each metering chamber, and the more than two impeller groups are arranged in parallel; the more than two impeller groups are located in different relative metering positions in their respective metering chambers. The embodiment of the present invention is suitable for occasions for metering of fuel gas and other gases.

Description

Technical Field

[0001] The present application relates to the technical field of flow meters, and in particular to a gas rotary flow meter and a gas flow measurement method. Background Art

[0002] Gas rotary (Roots) flowmeter is a metering instrument used to continuously or intermittently measure the flow of gas medium in pipelines. It has the characteristics of high accuracy, good reliability, long life, easy installation and use, and is a typical volumetric flowmeter. With the construction and popularization of gas transmission pipelines, rotary flowmeters are widely used in industrial and commercial trade measurement and standard verification due to their high accuracy and good repeatability.

[0003] Existing gas impeller flow meters are basically in the form of a single impeller and a housing combination. When this structure flow meter is used on site, the instantaneous flow discharged during normal operation presents sinusoidal fluctuations as the rotation angle of the impeller changes, that is, pulsation exists, resulting in poor repeatability of the flow meter, which is insufficient to meet applications requiring high precision. Summary of the invention

[0004] In view of this, the embodiments of the present application provide a gas impeller flowmeter and a gas flow measurement method, which can reduce the pulsation phenomenon caused by the instantaneous discharge flow.

[0005] In a first aspect, an embodiment of the present application is a gas rotary flow meter, comprising: more than two metering chambers, each metering chamber is provided with a rotary flow meter group, and the more than two rotary flow meters groups are arranged in parallel; the relative metering positions of the more than two rotary flow meters groups in their respective metering chambers are different.

[0006] According to a specific implementation of the embodiment of the present application, the two or more metering chambers are located in the same cavity; and air inlets are respectively provided on the cavity at positions corresponding to the respective metering chambers.

[0007] According to a specific implementation of the embodiment of the present application, the cavity has a common exhaust channel connected to the exhaust ports of at least two metering chambers, and the common exhaust channel extends along the length direction of the cavity and is connected to the outlet at one end of the cavity.

[0008] According to a specific implementation of the embodiment of the present application, an inter-group linkage mechanism is provided between two or more waist wheel groups.

[0009] According to a specific implementation of the embodiment of the present application, each waist wheel group includes a first rotor and a second rotor matched with the first rotor, and the inter-group linkage mechanism is connected to the first rotor or the second rotor of more than two waist wheel groups.

[0010] According to a specific implementation of the embodiment of the present application, the inter-group linkage mechanism is arranged outside the cavity and is connected to the end of the first rotor or the second rotor of more than two waist wheel groups.

[0011] According to a specific implementation of the embodiment of the present application, the first end of the first rotor of each waist gear set is connected to a first gear, and the first end of the second rotor of each waist gear set is connected to a second gear, and the first gear and the second gear are of the same size and mesh with each other;

[0012] The inter-group linkage mechanism is meshed with the first gear connected to the first rotor of the two or more waist gear groups, or is meshed with the second gear connected to the second rotor of the two or more waist gear groups.

[0013] According to a specific implementation of the embodiment of the present application, the inter-group linkage mechanism is a gear linkage mechanism or a synchronous belt.

[0014] According to a specific implementation of the embodiment of the present application, the gear linkage mechanism includes a group of inter-linked gears, which are rotatably arranged outside the cavity and mesh with a first gear connected to a first rotor of two or more waist gear sets, or mesh with a second gear connected to a second rotor of two or more waist gear sets;

[0015] or,

[0016] The gear linkage mechanism includes a main linkage gear, which is rotatably arranged outside the cavity, and an intermediate gear is arranged between the main linkage gear and a first gear connected to the first rotor of the two or more waist gear sets, and the intermediate gear is meshed with the main linkage gear and the first gear; or an intermediate gear is arranged between the main linkage gear and a second gear connected to the second rotor of the two or more waist gear sets, and the intermediate gear is meshed with the main linkage gear and the second gear;

[0017] or,

[0018] The gear linkage mechanism includes a gear ring, which is arranged outside the cavity and meshes with a first gear connected to a first rotor of more than two waist gear sets, or meshes with a second gear connected to a second rotor of more than two waist gear sets.

[0019] According to a specific implementation of the embodiment of the present application, each waist wheel assembly includes a first rotor and a second rotor matched with the first rotor;

[0020] In each waist wheel group, along the clockwise or counterclockwise direction, among the n first rotors from the first rotor of the first waist wheel group to the first rotor of the nth waist wheel group, the angle between the first rotors of adjacent waist wheel groups increases gradually with a predetermined angle gradient; wherein the first rotor of each waist wheel group is a rotor in the same installation sequence along the clockwise or counterclockwise direction among the two rotors of each waist wheel group;

[0021] The predetermined angle gradient is determined according to the following formula:

[0022] k = 90° / n ± 5°;

[0023] Where k is the predetermined angle gradient;

[0024] n is the number of waist wheel groups.

[0025] According to a specific implementation of the embodiment of the present application, the more than two metering chambers are two, three or four metering chambers.

[0026] According to a specific implementation of the embodiment of the present application, the partition wall between two adjacent metering cavities is a symmetrical structure relative to the symmetry center plane between the two adjacent metering cavities; the symmetry center plane passes through the central axis of the cavity;

[0027] or,

[0028] The partition wall between two adjacent metering cavities is an asymmetric structure relative to a symmetric center plane between the two adjacent metering cavities, wherein the symmetric center plane passes through the central axis of the cavity.

[0029] According to a specific implementation of the embodiment of the present application, the gas rotary flowmeter further includes a housing, and the metering module is detachably arranged in the housing; the metering module includes the cavity having a metering cavity therein, and a rotary group in each metering cavity;

[0030] The housing is provided with a first air inlet and a first air outlet for communicating with an external air flow delivery pipeline;

[0031] A first flow guiding channel communicating with the first air inlet and the air inlet of each metering cavity, and a second flow guiding channel communicating with the air outlet of the cavity and the first air outlet are provided in the shell.

[0032] According to a specific implementation of the embodiment of the present application, the shell includes a shell body, the shell body has an opening for taking and placing the metering module, and a cover body is provided at the opening; the metering module is arranged in the shell body; the first air inlet and the first air outlet are arranged on the shell body.

[0033] According to a specific implementation of the embodiment of the present application, the shell body includes a pipeline connecting portion and a metering module accommodating portion;

[0034] An airflow buffer chamber and an airflow discharge chamber are provided in the pipeline connection part, and the airflow buffer chamber and the airflow discharge chamber are isolated from each other; the first air inlet and the first air outlet are provided on the pipeline connection part; the airflow buffer chamber is respectively connected with the first air inlet and the air inlet of each metering chamber, and the airflow discharge chamber is respectively connected with the air outlet of the cavity and the first air outlet;

[0035] The metering module accommodating portion has a metering module accommodating cavity, and the metering module is arranged in the metering module accommodating cavity.

[0036] According to a specific implementation of the embodiment of the present application, the airflow discharge chamber is a cylindrical structure extending along the central axis of the shell, and the airflow buffer chamber is an incomplete annular structure surrounding the airflow discharge chamber.

[0037] According to a specific implementation of the embodiment of the present application, the air inlet of each metering cavity is arranged on the side wall of the cavity, and there is a predetermined gap between the entrance of the air inlet of each metering cavity and the inner wall of the metering module accommodating cavity; the airflow buffer cavity is connected to the predetermined gap, and the airflow buffer cavity and the metering module accommodating cavity form the first guide channel.

[0038] According to a specific implementation of the embodiment of the present application, a transition connecting pipe is connected to the air outlet of the cavity, and the transition connecting pipe extends from the air outlet of the cavity to the airflow discharge cavity, and the transition connecting pipe and the airflow discharge cavity form the second guide channel.

[0039] According to a specific implementation of the embodiment of the present application, a fluid filter is provided in the housing between the outlet of the airflow buffer cavity and the air inlet of each metering cavity.

[0040] According to a specific implementation of the embodiment of the present application, the metering module accommodating chamber is respectively connected to the airflow buffer chamber and the airflow discharge chamber;

[0041] A step is provided at a position where the metering module accommodating chamber is connected to the airflow buffer chamber, the fluid filter is supported on the step, and the metering module is supported on the fluid filter.

[0042] According to a specific implementation of the embodiment of the present application, the fluid filter element includes an annular bracket, a filter hole is opened on the side wall of the bracket, and a filter net is provided at a position on the bracket corresponding to the filter hole; wherein the bracket is supported on the step.

[0043] According to a specific implementation of the embodiment of the present application, a bypass opening capable of conducting the first flow guiding channel and the second flow guiding channel is provided on the side wall of the transition connecting pipe, and a pressure difference switch is provided at the bypass opening.

[0044] According to a specific implementation of the embodiment of the present application, the pressure difference switch component includes a fixed connecting component and an elastic acting component, the fixed connecting component is arranged on the transition connecting pipe, and the elastic acting component is arranged on the fixed connecting component, and closes the bypass opening when in a free state.

[0045] In a second aspect, an embodiment of the present application provides a gas flow metering method, which is applied to a gas impeller flowmeter, wherein the gas impeller flowmeter includes two or more metering chambers, each metering chamber is provided with a impeller group, and the two or more impeller groups are arranged in parallel; the gas flow metering method includes:

[0046] The airflow enters more than two metering chambers;

[0047] Two or more waist wheel groups are used for rotation measurement;

[0048] More than two metering chambers discharge airflow in a staggered manner according to a certain timing.

[0049] According to a specific implementation of the embodiment of the present application, more than two waist wheel groups perform rotational metering, including: the waist wheel groups in at least two metering chambers rotate in conjunction to perform metering.

[0050] According to a specific implementation of the embodiment of the present application, each waist wheel group includes a first rotor and a second rotor matched with the first rotor, and the first rotor or the second rotor of the waist wheel group in at least two metering chambers is connected by an inter-group linkage mechanism; wherein,

[0051] The waist wheel groups in the at least two metering chambers rotate in linkage, including:

[0052] The first rotor or the second rotor of the waist wheel group in the at least two metering chambers rotates in linkage with each other through the inter-group linkage mechanism.

[0053] According to a specific implementation of the embodiment of the present application, the first rotor of the waist wheel group in the at least two metering chambers is connected to a first gear, the second rotor is connected to a second gear, and the second gear is meshed with the first gear;

[0054] Wherein, the first rotor or the second rotor of the waist wheel group in the at least two metering chambers is linked to rotate through the inter-group linkage mechanism, including:

[0055] The first rotors of the waist wheel groups in the at least two metering chambers rotate in conjunction with each other through the meshing of the first gear with a gear linkage mechanism or a synchronous belt;

[0056] or,

[0057] The second rotors of the waist wheel groups in the at least two metering chambers rotate in linkage with each other through the meshing of the second gear with a gear linkage mechanism or a synchronous belt.

[0058] According to a specific implementation of the embodiment of the present application, the two or more metering chambers are discharged in a staggered manner according to a certain time sequence, including:

[0059] The airflow measured by each metering chamber is discharged through the respective exhaust ports of each metering chamber and merged into the common exhaust channel, and then discharged through the common exhaust channel;

[0060] or,

[0061] The airflow measured by the first metering chamber is discharged through the exhaust ports of the first metering chambers and merged into the first common exhaust channel, and then discharged through the first common exhaust channel; the airflow measured by the second metering chamber is discharged through the exhaust ports of the second metering chambers and merged into the second common exhaust channel, and then discharged through the second common exhaust channel;

[0062] or,

[0063] The number of the two or more metering chambers is N, where N is a natural number greater than 1 and less than or equal to 8; wherein the airflow after being metered by each metering chamber is discharged from the exhaust port, including:

[0064] The airflow measured by N-1 metering chambers is discharged through the respective exhaust ports of the N-1 metering chambers and merged into the common exhaust channel, and then discharged through the common exhaust channel; the airflow measured by one metering chamber is discharged through an independent exhaust channel connected to the exhaust port of the one metering chamber itself.

[0065] According to a specific implementation of the embodiment of the present application, each waist wheel assembly includes a first rotor and a second rotor matched with the first rotor;

[0066] In each of the waist wheel groups, along the clockwise or counterclockwise direction, among the n first rotors from the first rotor of the first waist wheel group to the first rotor of the nth waist wheel group, the angles of the first rotors of adjacent waist wheel groups relative to the air inlets of the respective metering chambers increase gradually with a predetermined angle gradient; wherein the first rotor of each waist wheel group is a rotor in the same installation sequence along the clockwise or counterclockwise direction among the two rotors of each waist wheel group;

[0067] The predetermined angle gradient is determined according to the following formula:

[0068] k = 90° / n ± 5°;

[0069] Where k is the predetermined angle gradient;

[0070] n is the number of waist wheel groups.

[0071] In the embodiment of the present application, a pulley group is respectively provided in two or more metering chambers, and the gas volume passing through the flow meter per unit time can be increased by measuring in multiple metering chambers at the same time, thereby improving the throughput of the flow meter. The pulley groups in the two or more metering chambers are located at different relative metering positions in their respective metering chambers, so that each metering chamber can discharge gas flow at a staggered peak, that is, the peaks or troughs of the gas flow discharged from each metering chamber can be staggered. In this way, the pulsation of the air flow discharged from the flow meter after the air flows discharged from each metering chamber merge are relatively gentle, which can effectively reduce the pulsation phenomenon of the gas flow discharged by the flow meter, thereby making the flow meter have better repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0073] Figure 1 This is a schematic diagram of the explosion structure of a gas rotary flowmeter according to an embodiment of the present invention;

[0074] Figure 2 This is a schematic diagram of the cross-sectional structure of a gas rotary flowmeter according to an embodiment of the present invention;

[0075] Figure 3 This is a schematic diagram of the internal structure of a gas rotary flowmeter according to an embodiment of the present invention;

[0076] Figure 4 for Figure 3 Schematic diagram of the cavity structure of the gas rotary flowmeter;

[0077] Figure 5 This is a schematic diagram of the arrangement structure of the waist wheel group in one embodiment of the present invention;

[0078] Figure 6 It is a schematic diagram of the arrangement structure of the linkage structure in one embodiment of the present invention;

[0079] Figure 7 It is a schematic diagram of the arrangement structure of the linkage structure in another embodiment of the present invention;

[0080] Figure 8 and Fig. 9 It is a schematic diagram of the arrangement structure of the linkage structure in another embodiment of the present invention;

[0081] Fig.10 A schematic diagram of the arrangement structure of the linkage structure in yet another embodiment of the present invention;

[0082] Fig.11a This is a schematic diagram of the arrangement structure of the waist wheel assembly in another embodiment of the present invention;

[0083] Fig.11b This is a schematic diagram of the arrangement structure of the waist wheel group in another embodiment of the present invention;

[0084] Fig.12 This is a schematic diagram of the arrangement structure of the waist wheel assembly in another embodiment of the present invention;

[0085] Fig.13 It is a schematic structural diagram of a gas rotary flowmeter with a housing according to another embodiment of the present invention;

[0086] Fig.14 It is a schematic cross-sectional structure diagram of a gas rotary flowmeter with a housing according to an embodiment of the present invention;

[0087] Fig.15 This is a flow chart of a gas flow measurement method according to an embodiment of the present invention;

[0088] Fig.16a and Fig.16b A schematic diagram of the gas flow direction in the gas flow measurement method according to an embodiment of the present invention;

[0089] Fig.17 FIG. 4 is a schematic diagram of the gas flow direction in a gas flow measurement method according to another embodiment of the present invention. DETAILED DESCRIPTION

[0090] The embodiments of the present application are described in detail below in conjunction with the accompanying drawings. It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0091] An embodiment of the present invention provides a gas rotary flow meter, comprising: more than two metering chambers, each metering chamber is provided with a rotary flow meter group, and the more than two rotary flow meters groups are arranged in parallel; the rotary flow meters groups in the more than two metering chambers are located in different relative metering positions in their respective metering chambers.

[0092] The more than two metering cavities may be two, three, four or more metering cavities.

[0093] In this embodiment, simultaneous measurement in multiple metering chambers can be performed, which can increase the volume of gas passing through the flow meter per unit time and improve the throughput of the flow meter. The waist wheel groups in two or more metering chambers are located at different relative metering positions in their respective metering chambers. While providing the throughput of the flow meter, the pulsation phenomenon of the gas flow discharged by the flow meter can be reduced, thereby improving the repeatability of the flow meter. The embodiment of the present invention can be used to measure gas such as fuel gas.

[0094] See also Figures 1 to 3 As shown, an embodiment of the present invention provides a gas rotary flow meter, including three metering chambers 10, wherein a rotary wheel group 20 is respectively provided in each metering chamber 10, and the rotary wheel groups 20 in the three metering chambers 10 are arranged in parallel; the rotary wheel groups 20 in the three metering chambers 10 are located in different relative metering positions in their respective metering chambers. Figure 1 The three metering chambers are 10a, 10b, and 10c respectively.

[0095] The waist wheel group 20 in each metering chamber 10 may include a first rotor 201 and a second rotor 202 matched with the first rotor 201. When three waist wheel groups 20 are arranged in parallel, the plane where the rotation center line of the first rotor 201 and the second rotor 202 in one waist wheel group is located is not on the same plane as the plane where the rotation center line of the first rotor 201 and the second rotor 202 in other waist wheel groups is located. The rotation center line of the first rotor 201 is the rotation axis center line of the first rotor 201, and the rotation center line of the second rotor 202 is the rotation axis center line of the second rotor 202.

[0096] Among them, the relative metering positions of the wheel groups 20 in the three metering chambers 10 in their respective metering chambers can be the relative positions of a rotor (such as the first rotor) in the same installation sequence among the three wheel groups 20 in their respective metering chambers.

[0097] The pulley groups 20 in the three metering chambers 10 are located at different relative metering positions in their respective metering chambers. For example, the pulley groups 20 in the three metering chambers 10 can be set at different angles relative to the air inlets of the respective metering chambers 10. In one example, the pulley groups 20 in the three metering chambers 10 can be set at different angles relative to the air inlets of the respective metering chambers 10. Specifically, the pulley groups 20 in the three metering chambers 10 are set at different angles relative to the air inlet directions of the air inlets of the respective metering chambers 10. The pulley groups 20 in a metering chamber 10 are set at different angles relative to the air inlet direction of the air inlet of the metering chamber 10. The maximum longitudinal section of any rotor in the pulley group 20 can be set at different angles relative to the air inlet direction of the air inlet of the metering chamber 10. The maximum longitudinal section of a rotor is the maximum longitudinal section of the rotor center axis passing through the rotor.

[0098] In other embodiments, the pulley groups 20 in the three metering chambers 10 may be arranged at different angles relative to the plane where the air inlet end or the air outlet end of the air inlet of each metering chamber 10 is located. The pulley group 20 in one metering chamber 10 may be arranged at different angles relative to the plane where the air inlet end or the air outlet end of the air inlet of the metering chamber 10 is located, and the maximum longitudinal section of any rotor in the pulley group 20 may be arranged at different angles relative to the plane where the air inlet end or the air outlet end of the air inlet of the metering chamber 10 is located.

[0099] The gas enters each metering cavity 10 from the air inlet of each metering cavity 10, and the air pressure difference between the outside and inside of the metering cavity 10 drives the waist wheel group 20 to rotate. After passing through the metering cavity 10, the gas flows out of each metering cavity 10 from the exhaust side (also called exhaust end or exhaust port, etc.) of each metering cavity 10. By counting the number of rotations of the rotor in each waist wheel group 20 (for example, the number of rotations of the rotor can be counted by a sensor provided at the end of the rotor), combined with the gas flow rate through the metering cavity 10 after one rotation of the rotor, the gas flowing through the flowmeter can be measured.

[0100] In this embodiment, there are three metering chambers 10 in the cavity, and a waist wheel group 20 is respectively provided in each metering chamber 10. The metering through the three metering chambers 10 can increase the gas volume passing through the flow meter per unit time, thereby improving the throughput of the flow meter.

[0101] The gas flow discharged from a single metering chamber 10 is pulsating. In this embodiment, three metering chambers 10 are adjacently arranged, and the waist wheel groups 20 in the three metering chambers 10 are located at different relative metering positions in their respective metering chambers, so that each metering chamber can discharge gas flow at a staggered peak, that is, the peaks or troughs of the gas flow discharged from each metering chamber can be staggered. In this way, after the gas flows discharged from each metering chamber converge, the pulsation of the gas flow discharged from the flowmeter is relatively gentle, which can effectively reduce the pulsation of the gas flow discharged by the flowmeter, thereby making the flowmeter more repeatable. The repeatability of a flowmeter refers to the difference in the gas flow measured by the flowmeter in different time periods. The smaller the difference, the better the repeatability of the flowmeter.

[0102] The pulley groups 20 in more than two metering chambers 10 are arranged in parallel, that is, more than two metering chambers 10 are arranged in parallel, so that the arrangement of each metering chamber 10 can be relatively compact, so that the volume of the flow meter is relatively small, and it is also convenient to quickly merge the airflows discharged from each metering chamber 10. The airflows discharged from each metering chamber 10 can be merged only through a shorter flow path, which can eliminate or reduce the pulsation phenomenon of the gas flow discharged by the flow meter earlier or faster.

[0103] See also Figure 3 to Figure 4For ease of assembly, in one example, more than two metering chambers 10 may be located in the same cavity 30, or in other words, more than two metering chambers 10 may be located in the same cavity 30; and air inlets 301 are provided at positions corresponding to the metering chambers 10 on the cavity 30.

[0104] See also Figure 2 and Figure 3 , an air outlet 302 is provided on the cavity 30, and the air outlet 302 is connected to the exhaust port of each metering cavity 10. In another example, there may be multiple air outlets on the cavity 30, and each metering cavity 10 corresponds to an air outlet. In addition to having more than two metering cavities 10 in the same cavity 30, in other embodiments, one or more separate metering cavities may be provided outside the cavity 30, and the one or more separate metering cavities may be used in conjunction with more than two metering cavities in the same cavity 30.

[0105] The cavity 30 may also be referred to as a mold cavity. In one example, the cavity has a common exhaust passage connected to the exhaust ports of at least two metering chambers, the common exhaust passage extends along the length direction of the cavity and is connected to the air outlet at one end of the cavity.

[0106] See also Figure 4 The cavity 30 may be in a hollow columnar shape, that is, the cavity 30 has a hollow structure 303 in the middle, and the metering cavity 10 and the waist wheel assembly 20 are extended along the length direction of the cavity 30, so that the volume of the metering cavity 10 can be increased. Among them, the three metering cavities 10 are arranged around the central axis of the cavity 30, and the hollow structure 303 in the middle of the cavity 30 is connected with the exhaust side of each metering cavity 10, so that the hollow structure 303 in the middle of the cavity 30 becomes a common exhaust channel for each metering cavity 10, and the common exhaust channel is connected with the gas outlet 302 of the flow meter, that is, the gas outlet 302 is connected with the hollow structure 303 in the middle of the cavity 30. The common exhaust channel is located in the middle of the cavity 30 and is connected to the airflow outlets of each metering cavity 10. The airflows discharged from each metering cavity 10 can be converged with the shortest possible flow path, or the airflows can be converged after being discharged from each metering cavity 10, which can eliminate or reduce the pulsation of the gas flow discharged by the flow meter earlier or faster.

[0107] See also Figure 1 and Figure 3The cavity 30 may include a cavity body 304 with openings at both ends, a first end plate 305 is provided at the first end of the cavity body 304, and a second end plate 306 is provided at the second end; an air inlet is provided on the cavity body 304, and an air outlet 302 is provided on the second end plate 306; each metering cavity 10 in the cavity 30 may include a first metering chamber 304a and a second metering chamber 304b surrounded by a wall, and the first metering chamber 304a and the second metering chamber 304b are arranged opposite to each other. In one example, the cross-sections of the first metering chamber 304a and the second metering chamber 304b may be semicircular, respectively.

[0108] The waist wheel assembly 20 in each metering chamber 10 may include a first rotor 201 and a second rotor 202 matched with the first rotor 201. The first rotor 201 and the second rotor 202 are long structures with an 8-shaped cross section.

[0109] The rotation radius of the first rotor 201 may be the same as the radius of the semicircle formed by the cross section of the first metering chamber 304a; the rotation radius of the second rotor 202 may be the same as the radius of the semicircle formed by the cross section of the second metering chamber 304b; wherein the second rotor 202 is the same size as the first rotor 201.

[0110] The first end of the first rotor 201 and the second rotor 202 of each waist wheel group 20 is rotatably disposed on the first end plate 305, and the second end is rotatably disposed on the second end plate 306. Bearings may be provided at the positions where the first rotor 201 and the second rotor 202 are rotatably connected to the first end plate 305 and the second end plate 306.

[0111] In one example, an end cover 307 is provided on the outer side of the second end plate 306, and the end cover 307 is connected to the second end plate 306; a through hole is provided on the end cover 307, and a transition connection pipe 308 is connected to the gas outlet 302, and the transition connection pipe 308 extends from the through hole on the end cover 307. There is a containing space between the end cover 307 and the second end plate 306, and the containing space can store lubricating oil for providing lubrication to the second ends of the first rotor 201 and the second rotor 202. In addition, the end cover 307 cooperates with the transition connection pipe 308 to prevent the gas discharged from the gas outlet 302 from having an adverse effect on the rotating connection structure (such as bearings, etc.) between the second ends of the first rotor 201 and the second rotor 202 and the second end plate 306.

[0112] In order to improve the accuracy of measurement, a linkage mechanism may be provided between the first rotor 201 and the second rotor 202 so that the rotation of the first rotor 201 and the second rotor 202 is linked, and the linkage mechanism between the first rotor 201 and the second rotor 202 may be referred to as an intra-group linkage mechanism. The intra-group linkage mechanism may be a gear linkage mechanism or a synchronous belt linkage mechanism, etc.

[0113] See also Figure 5 , the waist wheel groups 20 in the three metering chambers 10 are arranged at different angles relative to the air inlets of the respective metering chambers 10. In each waist wheel group 20, along the clockwise direction, among the three first rotors (201a, 201b, 201c) from the first rotor 201a of the first waist wheel group 20 to the first rotor 201c of the third waist wheel group 20, the angles of the first rotors of adjacent waist wheel groups 20 relative to the air inlets of the respective metering chambers 10 increase gradually by an angle gradient of 30°±5°; wherein, the first rotor of each waist wheel group 20 is a rotor in the first installation sequence along the clockwise direction among the two rotors of each waist wheel group 20. Figure 5 In the figure, the first rotor 201a, the first rotor 201b and the first rotor 201c are a rotor that is in a first installation sequence in a clockwise direction.

[0114] The angle between the first rotors 201 of adjacent waist wheel groups 20 and the air inlet of each metering cavity 10 specifically refers to the angle between the maximum longitudinal section passing through the rotation center axis of the first rotor 201 and the air inlet direction of the air inlet of the metering cavity 10 where the first rotor 201 is located.

[0115] See also Figure 5 In one example, the angles of the first rotors 201 of the adjacent waist wheel groups 20 relative to the air inlets of the respective metering chambers 10 increase gradually by 30°.

[0116] In order to ensure that the waist wheel group 20 in the three metering chambers 10 has a relatively stable relative position during the metering process, and further reduce the pulsation phenomenon of the gas flow discharged by the flow meter, see Figures 6 to 10 In one example, an inter-group linkage mechanism 40 is provided between the pulley groups 20 in the three metering chambers 10, so that the rotation of the pulley groups 20 in the three metering chambers 10 is linked. In any time period, the total gas discharge volume after the gas flow rates discharged from each metering chamber 10 are superimposed can remain relatively stable.

[0117] See also Figure 6 In one example, the inter-group linkage mechanism 40 is connected to the first rotor 201 of each waist wheel group 20.

[0118] The inter-group linkage mechanism 40 may be disposed outside the cavity 30 and connected to the ends of the first rotors 201 of the two or more waist wheel groups. In one example, the first end of the first rotor 201 of each waist wheel group is connected to a first gear 2011, and the first end of the second rotor 202 of each waist wheel group is connected to a second gear 2012, and the first gear 2011 and the second gear 2012 are of the same size and mesh with each other; the inter-group linkage mechanism meshes with the first gear 2011 connected to the first rotors 201 of the two or more waist wheel groups.

[0119] For example, see Figure 1 The inter-group linkage mechanism 40 is arranged on the outside of the first end plate 305 and is connected to the end of the first rotor 201 of each waist wheel group 20; wherein the outside of the first end plate 305 is the side of the first end plate 305 facing away from the waist wheel group 20.

[0120] The first rotor 201 and the second rotor 202 of each waist wheel group 20 have rotating shafts at both ends respectively; the rotating shaft at the first end of the first rotor 201 of each waist wheel group 20 passes through the through hole on the first end plate 305 and is connected to the first gear 2011; the rotating shaft at the first end of the second rotor 202 of each waist wheel group 20 passes through the through hole on the first end plate 305 and is connected to the second gear 2012; the first gear 2011 and the second gear 2012 are of the same size and mesh with each other; the first gear 2011 and the second gear 2012 form an intra-group linkage mechanism; the inter-group linkage mechanism 40 meshes with the first gear 2011 connected to the first rotor 201 of each waist wheel group 20.

[0121] The inter-group linkage mechanism 40 may be a gear linkage mechanism. Figure 6 Specifically, the inter-group linkage mechanism 40 includes a main linkage gear 401a, and an intermediate gear 402a is provided between the main linkage gear 401a and the first gear 2011 connected to the first rotor 201 of each waist gear group 20, and the intermediate gear 402a is meshed with the main linkage gear 401a and the first gear 2011.

[0122] This embodiment is not limited to this. In other embodiments, an intermediate gear 402a is provided between the main linkage gear 401a and the second gear 2012 connected to the second rotor 202 of each waist gear set 20, and the intermediate gear 402a is meshed with the main linkage gear 401a and the second gear 2012.

[0123] In this embodiment, the main linkage gear 401a is rotatably disposed at the center position of the outer side of the first end plate 305, and is meshed with the first gear 2011 connected to the first rotor 201 of each waist wheel group 20 through the intermediate gear 402a, and is not meshed with the second gear 2012 connected to the second rotor 202 of each waist wheel group 20. In this case, the distances from the rotation centers of the first rotor 201 and the second rotor 202 to the rotation center of the main linkage gear 401a can be the same, so that the partition wall between two adjacent metering chambers 10 is a symmetrical structure relative to the symmetry center plane between the two adjacent metering chambers 10; the symmetry center plane passes through the central axis of the chamber body 30.

[0124] See also Figure 7As a replacement setting of the intermediate gear 402a, the intermediate gear 402a can be replaced by an intermediate gear 402b that is coaxially linked with the second rotor 202 of each waist gear set 20. The intermediate gear 402b and the first rotor 202 of each waist gear set 20 form a double gear.

[0125] In this embodiment, the air outlet 302 is provided on the second end plate 306 . In other embodiments, the air outlet 302 may also be provided on the first end plate 305 .

[0126] In this embodiment, the inter-group linkage mechanism 40 is arranged on the outside of the first end plate 305. In other embodiments, the inter-group linkage mechanism 40 may also be arranged on the outside of the second end plate 306. The outside of the second end plate 306 is the side of the second end plate 306 facing away from the waist wheel group 20. In this embodiment, the inter-group linkage mechanism 40 is connected to the end of the first rotor 201 of each waist wheel group 20. In other embodiments, the inter-group linkage mechanism 40 may also be connected to the end of the second rotor 202 of each waist wheel group 20.

[0127] Figure 8 and Fig. 9 FIG. 1 is a schematic diagram of an inter-group linkage mechanism of a gas rotary flowmeter according to another embodiment of the present invention. Figure 8 and Fig. 9 , the mechanism of this embodiment is Figure 1 The structures of the embodiments shown are basically the same, except that, in the present embodiment, the gear linkage mechanism includes an inter-group linkage gear 401b, which is rotatably disposed outside the first end plate 305 and meshes with the first gear 2011 connected to the first rotor 201 of each waist gear set 20. The inter-group linkage gear 401b is not meshed with the second gear 2012 connected to the second rotor 202 of each waist gear set 20.

[0128] In this embodiment, the inter-group linkage gear 401b is rotatably disposed at the center position of the outer side of the first end plate 305, directly meshing with the first gear 2011 connected to the first rotor 201 of each waist wheel group 20, and not meshing with the second gear 2012 connected to the second rotor 202 of each waist wheel group 20. In this case, the distances from the rotation center of the first rotor 201 and the second rotor 202 to the rotation center of the inter-group linkage gear 401b are different, so that the partition wall between two adjacent metering chambers 10 can also be an asymmetric structure relative to the symmetric center plane between the two adjacent metering chambers 10. The symmetric center plane passes through the central axis of the cavity 30.

[0129] Fig.10 FIG. 1 is a schematic diagram of an inter-group linkage mechanism of a gas rotary flowmeter according to another embodiment of the present invention. Fig.10 , the mechanism of this embodiment is Figure 1The structures of the embodiments shown are basically the same, except that, in this embodiment, the inter-group linkage mechanism 40 includes a ring gear 401c, which is arranged on the outside of the first end plate 305 and meshes with the first gear 2011 connected to the first rotor 201 of each waist gear group 20.

[0130] This embodiment is not limited thereto. In other embodiments, the ring gear 401 c may also mesh with the second gear 2012 connected to the second rotor 202 of each waist gear assembly 20 .

[0131] In another embodiment, the ring gear 401c may be replaced by a synchronous belt.

[0132] Fig.11a This is a schematic diagram of the structure of a gas rotary flowmeter according to another embodiment of the present invention. Fig.11b FIG. 1 is a schematic diagram of the structure of a gas rotary flowmeter according to another embodiment of the present invention. Fig.11a and Fig.11b , the mechanism of this embodiment is Figure 1 The structures of the embodiments shown are basically the same, except that, in the present embodiment, four metering chambers 10 are provided in the cavity 30, each metering chamber 10 is provided with a pulley group 20, and the four pulley groups 20 in the four metering chambers 10 are arranged in parallel; similar to the embodiment in which three metering chambers 10 are provided in the cavity 30, in the present embodiment, in each pulley group 20, along the clockwise direction, in the four first rotors 201 from the first rotor 201 of the first pulley group 20 to the first rotor 201 of the fourth pulley group 20, the angles of the first rotors 201 of adjacent pulley groups 20 relative to the air inlets of the respective metering chambers 10 increase with an angle gradient of 22.5°±5°; wherein, the first rotor 201 of each pulley group 20 is a rotor in the first installation sequence along the clockwise direction among the two rotors of each pulley group 20.

[0133] Fig.11a In the embodiment, the distances from the rotation centers of the first rotor and the second rotor to the rotation centers of the inter-group linkage gear are the same, so that the partition wall between two adjacent metering cavities can also be a symmetrical structure relative to the symmetric center plane between the two adjacent metering cavities. The symmetric center plane passes through the central axis of the cavity.

[0134] Fig.11b In the embodiment, the distances from the rotation centers of the first rotor and the second rotor to the rotation centers of the inter-group linkage gear are the same, so that the partition wall between two adjacent metering cavities can also be a symmetrical structure relative to the symmetric center plane between the two adjacent metering cavities. The symmetric center plane passes through the central axis of the cavity.

[0135] In the above embodiment, the cavity 30 has three or four metering chambers 10. The embodiment of the present invention is not limited thereto, and the cavity 30 may also have other numbers of metering chambers 10, such as two (eg Fig.12 When there are multiple metering chambers 10 in the cavity 30, each waist wheel group 20 includes a first rotor 201 and a second rotor 202 matched with the first rotor 201; the setting angle of the rotor of each waist wheel group 20 can be determined as follows:

[0136] In each of the waist wheel groups 20, along the clockwise or counterclockwise direction, among the n first rotors 201 from the first rotor 201 of the first waist wheel group 20 to the first rotor 201 of the nth waist wheel group 20, the angles of the first rotors 201 of the adjacent waist wheel groups 20 relative to the air inlet (specifically, the air inlet direction of the air inlet) of the respective metering chambers 10 increase gradually in a predetermined angle; wherein the first rotor 201 of each waist wheel group 20 is a rotor in the same installation sequence along the clockwise or counterclockwise direction among the two rotors of each waist wheel group 20;

[0137] The predetermined angle gradient is determined according to the following formula:

[0138] k = 90° / n ± 5°;

[0139] Where k is the predetermined angle gradient;

[0140] n is the number of waist wheel groups, and n can be a natural number greater than or equal to 2 and less than or equal to 8.

[0141] Fig.13 This is a schematic diagram of the structure of a gas rotary flowmeter according to another embodiment of the present invention. Fig.14 FIG. 1 is a cross-sectional structural diagram of a gas rotary flowmeter according to another embodiment of the present invention. Fig.13 and Fig.14 , the mechanism of this embodiment is Figure 1 The structures of the embodiments shown are basically the same, except that the gas rotary flowmeter further comprises a housing 50, and the metering module is detachably arranged in the housing 50. The metering module comprises a cavity 30 having three metering cavities 10 therein, and a rotary group 20 in each metering cavity 10.

[0142] The shell 50 has a shell air inlet 501 (hereinafter referred to as the first air inlet) and a shell air outlet 502 (hereinafter referred to as the first air outlet) for communicating with an external air flow delivery pipeline; the shell 50 has a first guide channel connecting the first air inlet and the air inlet of each metering cavity 10 (hereinafter referred to as the second air inlet), and a second guide channel connecting the air outlet 302 (hereinafter referred to as the second air outlet) on the cavity 30 and the first air outlet.

[0143] In this embodiment, the metering module is detachably arranged in the shell 50. When the metering module fails, the metering module can be removed from the shell 50 for quick repair or replacement, so as to reduce the impact on the normal production and life of downstream users caused by the failure of the metering module in the rotary flow meter.

[0144] In one example, the shell 50 includes a shell body 503, the shell body 503 has an opening for taking and placing the metering module, and a cover body 504 is provided at the opening; wherein, the shell body 503 includes a pipeline connecting part 5031 and a metering module accommodating part 5032; an airflow buffer chamber 50311 and an airflow discharge chamber 50312 are provided in the pipeline connecting part 5031, and the airflow buffer chamber 50311 and the airflow discharge chamber 50312 are isolated; the first air inlet and the first air outlet are arranged on the pipeline connecting part 5031, for connecting to an external gas delivery pipeline; the airflow buffer chamber 50311 is respectively connected to the first air inlet and the second air inlet, and the airflow discharge chamber 50312 is respectively connected to the second air outlet and the first air outlet; the metering module accommodating part 5032 has a metering module accommodating chamber, and the metering module is arranged in the metering module accommodating chamber.

[0145] The airflow buffer chamber 50311 can buffer the inflowing gas. When the fluid contains impurities such as larger particles of impurities such as welding slag, after the fluid enters the airflow buffer chamber 50311, due to the influence of gravity, some of the impurities in the fluid may be first precipitated in the airflow buffer chamber 50311.

[0146] In one example, the airflow discharge chamber 50312 is a cylindrical structure extending along the central axis of the shell 50, and the airflow buffer chamber 50311 is an incomplete annular structure surrounding the airflow discharge chamber 50312, which has a larger buffer space.

[0147] A linkage mechanism accommodating chamber a is formed between the cover body 504 and the first end plate 305 of the metering module, and the inter-group linkage mechanism 40 is located in the linkage mechanism accommodating chamber a, which can reduce the adverse effects of the metering gas on the inter-group linkage mechanism 40, such as corrosion.

[0148] In one example, the second air inlet is arranged on the side wall of the cavity 30, and there is a predetermined gap b between the entrance of the second air inlet and the inner wall of the metering module accommodating cavity; the airflow buffer cavity 50311 is connected to the predetermined gap b, and the airflow buffer cavity 50311 and the metering module accommodating cavity form the first guide channel.

[0149] The predetermined gap b between the entrance of the second air inlet and the inner wall of the metering module accommodating chamber can further buffer the airflow. After the airflow enters the metering module accommodating chamber from the airflow buffer chamber 50311, the predetermined gap b can make the airflow enter each metering chamber 10 more smoothly.

[0150] In one example, in the shell 50, a fluid filter 60 is provided between the outlet of the airflow buffer chamber 50311 and the second air inlet, which can filter impurities in the fluid and prevent impurities in the airflow from entering the metering chamber 10 to affect or even jam the rotation of the rotor in the waist wheel assembly 20.

[0151] The metering module accommodating chamber is respectively connected with the airflow buffer chamber 50311 and the airflow discharge chamber 50312; a step is provided at the position where the metering module accommodating chamber is connected with the airflow buffer chamber 50311, and the fluid filter element 60 is supported on the step, and the metering module is supported on the fluid filter element 60.

[0152] In one example, the fluid filter 60 includes an annular support, a filter hole is formed on the side wall of the support, and a filter screen is provided at a position on the support corresponding to the filter hole; wherein the support is supported on the step. One end of the support can be sealed and connected to the bottom of the metering module, and the other end can be sealed and connected to the step surface of the step.

[0153] In one example, a transition connecting pipe 308 is connected to the air outlet of the cavity 30, and the transition connecting pipe 308 extends from the air outlet of the cavity 30 to the airflow discharge cavity 50312, and the transition connecting pipe 308 and the airflow discharge cavity 50312 form the second guide channel. The transition connecting pipe 308 passes through the center of the bracket.

[0154] After the external airflow enters the airflow buffer chamber 50311 from the first air inlet, it passes through the fluid filter 60 and enters the predetermined gap b in the metering module accommodating chamber, and then enters each metering chamber 10 through the second air inlet at the predetermined gap b. After passing through each metering chamber 10, it converges into the common exhaust channel formed by the hollow structure 303 in the middle of the cavity 30, enters the transition connecting pipe 308 through the second air outlet connected to the common exhaust channel, and is guided by the transition connecting pipe 308 to the airflow discharge chamber 50312, and then is discharged to the external gas transmission channel through the first air outlet connected to the airflow discharge chamber 50312.

[0155] When for some reason, the rotor of the pulley assembly 20 in the metering module is stuck, the metering module cannot work normally, which affects the normal production and life of downstream users. To avoid this situation, in one example, a bypass opening that can connect the first guide channel and the second guide channel is provided on the side wall of the transition connecting pipe 308, and a pressure difference switch 70 is provided at the bypass opening.

[0156] When the rotor of the waist wheel assembly 20 is stuck, after the gas flows into the airflow buffer chamber 50311 from the first air inlet, the pressure difference between the airflow buffer chamber 50311 and the airflow exhaust chamber 50312 increases. When it reaches a certain threshold, the pressure difference switch 70 is actuated to connect the airflow buffer chamber 50311 and the airflow exhaust chamber 50312, thereby realizing temporary air supply to downstream users.

[0157] In one example, the differential pressure switch element 70 includes a fixed connection element and an elastic action element, wherein the fixed connection element is disposed on the transition connection pipe 308, and the elastic action element is disposed on the fixed connection element and closes the bypass opening when in a free state.

[0158] The fixed connection member may be a component used to fix the elastic action member, and the specific structural form is not limited.

[0159] The elastic action member may include a component made of elastic material. The elastic action member may generate displacement under the action of a predetermined pressure difference.

[0160] The elastic acting part can be implemented in various forms. In order to make the flow meter structure of this embodiment simpler, in some examples, the elastic acting part includes: a baffle portion and an elastic connecting portion, one end of the elastic connecting portion is connected to the baffle portion, and the other end is connected to the fixed connecting member; the baffle portion covers the bypass outlet opened on the transition connecting pipe 308, and the size of the baffle portion is larger than the aperture size at the bypass outlet.

[0161] The baffle portion can be made of any material that is impermeable to fluid, the shape of the baffle portion can be any shape, and the thickness can be designed according to the pressure required to be borne during actual use. The size of the baffle portion is larger than the aperture size at the bypass outlet, so that the bypass is easily closed.

[0162] The elastic connection part may be made of an elastic material and can be deformed under the action of an external force.

[0163] The present application also provides a gas flow metering method, which is applied to a gas impeller flowmeter. The gas impeller flowmeter includes more than two metering chambers, each of which is provided with a impeller group, and the more than two impeller groups are arranged in parallel. The gas flow metering method includes the following steps:

[0164] S100, airflow enters more than two metering chambers;

[0165] The waist wheel group in each metering chamber may include a first rotor and a second rotor matched with the first rotor. When the three waist wheel groups are arranged in parallel, the plane where the rotation center axis of the first rotor and the second rotor in one waist wheel group is located is not on the same plane as the plane where the rotation center axis of the first rotor and the second rotor in other waist wheel groups is located.

[0166] S102, two or more waist wheel groups are rotated for measurement.

[0167] S104. Two or more metering chambers discharge airflow in a staggered manner according to a certain time sequence.

[0168] More than two metering chambers discharge gas flows at different peaks according to a certain time sequence, which may mean that during the metering process, the time points at which the maximum peak gas flow rates are discharged from the two or more metering chambers are different. For example, there is a certain lag between the time point at which one metering chamber discharges the maximum peak gas flow rate and the time point at which another metering chamber discharges the maximum peak gas flow rate.

[0169] In the embodiment of the present application, more than two metering chambers discharge airflows at staggered peaks according to a certain timing, so that the peaks or troughs of the gas flow discharged from each metering chamber can be staggered with each other. In this way, after the airflows discharged from each metering chamber are merged, the pulsation of the airflow discharged from the flow meter is relatively gentle, which can effectively reduce the pulsation phenomenon of the gas flow discharged by the flow meter, thereby improving the repeatability of the flow meter.

[0170] In order to ensure that the pulley groups in each metering chamber have a relatively stable relative position during the metering process and further reduce the pulsation phenomenon of the gas flow discharged by the flow meter, in an example, the two or more pulley groups perform rotational metering (step S102), which may include: the pulley groups in at least two metering chambers rotate in conjunction to perform metering.

[0171] The waist wheel groups in each metering cavity rotate in conjunction, and in any time period, the total gas discharge volume after the gas flow discharged from each metering cavity is superimposed can be kept relatively stable.

[0172] In one example, each waist wheel group includes a first rotor and a second rotor matching the first rotor, and the first rotor or the second rotor of the waist wheel group in at least two metering chambers is connected by an inter-group linkage mechanism; wherein, the waist wheel groups in the at least two metering chambers rotate in linkage, which may include: the first rotor or the second rotor of the waist wheel group in the at least two metering chambers rotates in linkage through the inter-group linkage mechanism.

[0173] In one example, the first rotor of the waist wheel set in the at least two metering chambers is connected to a first gear, the second rotor is connected to a second gear, and the second gear is meshed with the first gear;

[0174] The first rotor or the second rotor of the waist wheel group in the at least two metering chambers rotates in linkage with each other through an inter-group linkage mechanism, comprising: the first rotor of the waist wheel group in the at least two metering chambers rotates in linkage with each other through the meshing of the first gear with a gear linkage mechanism or a synchronous belt;

[0175] This embodiment is not limited to this. In other embodiments, the first rotor or the second rotor of the waist wheel group in the at least two metering chambers is rotated in conjunction with the inter-group linkage mechanism, including: the second rotor of the waist wheel group in the at least two metering chambers is rotated in conjunction with the meshing of the second gear with a gear linkage mechanism or a synchronous belt.

[0176] See also Figure 5 In one example, the two or more metering chambers are discharged at a staggered time sequence (step S104), including: the airflow after being measured by each metering chamber is discharged through the respective exhaust ports of each metering chamber and merged into the common exhaust channel, and then discharged through the common exhaust channel.

[0177] See also Fig.16a and Fig.16b In another example, the two or more metering chambers are discharged in a staggered manner according to a certain timing (step S104), including: the airflow measured by the first part of the metering chamber is discharged through the exhaust ports of the first part of the metering chambers and merged into the first common exhaust channel, and then discharged through the first common exhaust channel; the airflow measured by the second part of the metering chamber is discharged through the exhaust ports of the second part of the metering chambers and merged into the second common exhaust channel, and then discharged through the second common exhaust channel.

[0178] See also Fig.17 In another example, the two or more metering chambers are discharged in a staggered manner according to a certain timing (step S104), including: the airflow after being metered by N-1 metering chambers is discharged through the respective exhaust ports of the N-1 metering chambers and merged into the common exhaust channel, and then discharged through the common exhaust channel; the airflow after being metered by one metering chamber is discharged through the independent exhaust channel connected to the exhaust port of the one metering chamber itself. Wherein, N is the number of metering chambers, and N is a natural number greater than 1 and less than or equal to 8.

[0179] In one example, each waist wheel group includes a first rotor and a second rotor matched with the first rotor; in each waist wheel group, along the clockwise or counterclockwise direction, among the n first rotors from the first rotor of the first waist wheel group to the first rotor of the nth waist wheel group, the angles of the first rotors of adjacent waist wheel groups relative to the air inlets of the respective metering chambers increase gradually with a predetermined angle gradient; wherein the first rotor of each waist wheel group is a rotor in the same installation sequence along the clockwise or counterclockwise direction among the two rotors of each waist wheel group; the predetermined angle gradient is determined according to the following formula:

[0180] k = 90° / n ± 5°;

[0181] Where k is the predetermined angle gradient;

[0182] n is the number of waist wheel groups.

[0183] The gas flow measurement method of this embodiment can be applied to the aforementioned gas rotary flow meter, and its beneficial effects are basically the same as those of the aforementioned gas rotary flow meter, which will not be described in detail here.

[0184] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0185] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0186] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A gas rotary flow meter, characterized in that: include: There are more than two metering chambers, each metering chamber is provided with a waist wheel group, and the more than two waist wheel groups are arranged in parallel; Two or more waist wheel groups are located at different relative metering positions in their respective metering chambers; The two or more metering chambers are located in the same chamber; and air inlets are respectively provided at positions corresponding to the respective metering chambers on the chamber; The cavity has a common exhaust passage connected to the exhaust ports of at least two metering chambers, the common exhaust passage extends along the length direction of the cavity and is connected to the exhaust port at one end of the cavity; An inter-group linkage mechanism is provided between two or more waist wheel groups; Each waist wheel group includes a first rotor and a second rotor matched with the first rotor, and the inter-group linkage mechanism is connected to the first rotor or the second rotor of more than two waist wheel groups.

2. The gas rotary flowmeter according to claim 1, characterized in that: The inter-group linkage mechanism is arranged outside the cavity and is connected to the end of the first rotor or the second rotor of more than two waist wheel groups.

3. The gas rotary flow meter according to claim 2, characterized in that: The first end of the first rotor of each waist gear set is connected to a first gear, and the first end of the second rotor of each waist gear set is connected to a second gear, and the first gear and the second gear are of the same size and mesh with each other; The inter-group linkage mechanism is meshed with the first gear connected to the first rotor of the two or more waist gear groups, or is meshed with the second gear connected to the second rotor of the two or more waist gear groups.

4. The gas rotary flow meter according to claim 3, characterized in that: The inter-group linkage mechanism is a gear linkage mechanism or a synchronous belt.

5. The gas rotary flow meter according to claim 4, characterized in that: The gear linkage mechanism includes a group of inter-linked gears, which are rotatably arranged outside the cavity and mesh with a first gear connected to a first rotor of two or more waist gear sets, or mesh with a second gear connected to a second rotor of two or more waist gear sets; or, The gear linkage mechanism includes a main linkage gear, which is rotatably arranged outside the cavity, and an intermediate gear is arranged between the main linkage gear and a first gear connected to the first rotor of the two or more waist gear sets, and the intermediate gear is meshed with the main linkage gear and the first gear; or an intermediate gear is arranged between the main linkage gear and a second gear connected to the second rotor of the two or more waist gear sets, and the intermediate gear is meshed with the main linkage gear and the second gear; or, The gear linkage mechanism includes a gear ring, which is arranged outside the cavity and meshes with a first gear connected to a first rotor of more than two waist gear sets, or meshes with a second gear connected to a second rotor of more than two waist gear sets.

6. The gas rotary flow meter according to claim 1, characterized in that: Each waist wheel assembly includes a first rotor and a second rotor matched with the first rotor; In each of the waist wheel groups, along the clockwise or counterclockwise direction, among the n first rotors from the first rotor of the first waist wheel group to the first rotor of the nth waist wheel group, the angles of the first rotors of adjacent waist wheel groups relative to the air inlets of the respective metering chambers increase gradually with a predetermined angle gradient; wherein the first rotor of each waist wheel group is a rotor in the same installation sequence along the clockwise or counterclockwise direction among the two rotors of each waist wheel group; The predetermined angle gradient is determined according to the following formula: k = 90° / n ±5°; Where k is the predetermined angle gradient; n is the number of waist wheel groups.

7. The gas rotary flow meter according to claim 1, characterized in that: The more than two metering chambers are two, three or four metering chambers.

8. The gas rotary flow meter according to claim 1, characterized in that: The partition wall between two adjacent metering cavities is a symmetrical structure relative to the symmetric center plane between the two adjacent metering cavities; the symmetric center plane passes through the central axis of the cavity; or, The partition wall between two adjacent metering cavities is an asymmetric structure relative to a symmetric center plane between the two adjacent metering cavities, and the symmetric center plane passes through the central axis of the cavity.

9. The gas rotary flow meter according to claim 1, characterized in that: It also includes a housing, in which a metering module is detachably arranged; the metering module includes a cavity body having a metering cavity inside, and a waist wheel group in each metering cavity; The housing is provided with a first air inlet and a first air outlet for communicating with an external air flow delivery pipeline; A first flow guiding channel communicating with the first air inlet and the air inlet of each metering cavity, and a second flow guiding channel communicating with the air outlet of the cavity and the first air outlet are provided in the shell.

10. The gas rotary flow meter according to claim 9, characterized in that: The shell comprises a shell body, the shell body has an opening for taking and placing the metering module, and a cover body is provided at the opening; the metering module is arranged in the shell body; the first air inlet and the first air outlet are arranged on the shell body.

11. The gas rotary flow meter according to claim 10, characterized in that: The shell body includes a pipeline connecting portion and a metering module accommodating portion; An airflow buffer chamber and an airflow discharge chamber are provided in the pipeline connection part, and the airflow buffer chamber and the airflow discharge chamber are isolated from each other; the first air inlet and the first air outlet are provided on the pipeline connection part; the airflow buffer chamber is respectively connected with the first air inlet and the air inlet of each metering chamber, and the airflow discharge chamber is respectively connected with the air outlet of the cavity and the first air outlet; The metering module accommodating portion has a metering module accommodating cavity, and the metering module is arranged in the metering module accommodating cavity.

12. The gas rotary flow meter according to claim 11, characterized in that: The airflow discharge chamber is a cylindrical structure extending along the central axis of the shell, and the airflow buffer chamber is an incomplete annular structure surrounding the airflow discharge chamber.

13. The gas rotary flow meter according to claim 11, characterized in that: The air inlet of each metering cavity is arranged on the side wall of the cavity, and there is a predetermined gap between the entrance of the air inlet of each metering cavity and the inner wall of the metering module accommodating cavity; the airflow buffer cavity is connected with the predetermined gap, and the airflow buffer cavity and the metering module accommodating cavity form the first guide channel.

14. The gas rotary flow meter according to claim 11, characterized in that: The air outlet of the cavity is connected with a transition connecting pipe, and the transition connecting pipe extends from the air outlet of the cavity to the airflow discharge cavity. The transition connecting pipe and the airflow discharge cavity form the second guide channel.

15. The gas rotary flow meter according to claim 11, characterized in that: In the housing, a fluid filter is provided between the outlet of the airflow buffer cavity and the air inlet of each metering cavity.

16. The gas rotary flow meter according to claim 15, characterized in that: The metering module accommodating chamber is respectively connected to the airflow buffer chamber and the airflow discharge chamber; A step is provided at a position where the metering module accommodating chamber is connected to the airflow buffer chamber, the fluid filter is supported on the step, and the metering module is supported on the fluid filter.

17. The gas rotary flow meter according to claim 16, characterized in that: The fluid filter element comprises an annular bracket, a filter hole is formed on the side wall of the bracket, and a filter net is provided at a position on the bracket corresponding to the filter hole; wherein the bracket is supported on the step.

18. The gas rotary flow meter according to claim 14, characterized in that: A bypass opening capable of conducting the first flow guiding channel and the second flow guiding channel is provided on the side wall of the transition connecting pipe, and a pressure difference switch is provided at the bypass opening.

19. The gas rotary flow meter according to claim 18, characterized in that: The differential pressure switch comprises a fixed connection member and an elastic action member, wherein the fixed connection member is arranged on the transition connection pipe, and the elastic action member is arranged on the fixed connection member and closes the bypass opening when in a free state.

20. A gas flow measurement method, characterized in that: Applied to a gas rotary flowmeter, the gas rotary flowmeter comprises more than two metering chambers, each metering chamber is provided with a rotary group, and the more than two rotary groups are arranged in parallel; the gas flow metering method comprises: The airflow enters more than two metering chambers; Two or more waist wheel groups are used for rotation measurement; More than two metering chambers discharge airflow in a staggered manner according to a certain time sequence; The two or more metering chambers are located in the same chamber; and air inlets are respectively provided at positions corresponding to the respective metering chambers on the chamber; The cavity has a common exhaust passage connected to the exhaust ports of at least two metering chambers, the common exhaust passage extends along the length direction of the cavity and is connected to the exhaust port at one end of the cavity; The two or more waist wheel groups perform rotational metering, including: waist wheel groups in at least two metering chambers rotate in conjunction with each other to perform metering; Each waist wheel group includes a first rotor and a second rotor matching the first rotor, and the first rotor or the second rotor of the waist wheel group in at least two metering chambers is connected by an inter-group linkage mechanism; wherein, the waist wheel groups in the at least two metering chambers rotate in linkage, including: the first rotor or the second rotor of the waist wheel group in the at least two metering chambers rotates in linkage through the inter-group linkage mechanism.

21. The gas flow measurement method according to claim 20, characterized in that: The first rotor of the waist wheel set in the at least two metering chambers is connected to a first gear, and the second rotor is connected to a second gear, and the second gear is meshed with the first gear; Wherein, the first rotor or the second rotor of the waist wheel group in the at least two metering chambers is linked to rotate through the inter-group linkage mechanism, including: The first rotors of the waist wheel groups in the at least two metering chambers rotate in conjunction with each other through the meshing of the first gear with a gear linkage mechanism or a synchronous belt; or, The second rotors of the waist wheel groups in the at least two metering chambers rotate in linkage with each other through the meshing of the second gear with a gear linkage mechanism or a synchronous belt.

22. The gas flow measurement method according to claim 20, characterized in that: The two or more metering chambers are discharged in a staggered manner according to a certain time sequence, including: The airflow measured by each metering chamber is discharged through the respective exhaust ports of each metering chamber and merged into the common exhaust channel, and then discharged through the common exhaust channel; or, The airflow measured by the first metering chamber is discharged through the exhaust ports of the first metering chambers and merged into the first common exhaust channel, and then discharged through the first common exhaust channel; the airflow measured by the second metering chamber is discharged through the exhaust ports of the second metering chambers and merged into the second common exhaust channel, and then discharged through the second common exhaust channel; or, The number of the two or more metering chambers is N, where N is a natural number greater than 1 and less than or equal to 8; wherein the airflow after being metered by each metering chamber is discharged from the exhaust port, including: The airflow measured by N-1 metering chambers is discharged through the respective exhaust ports of the N-1 metering chambers and merged into the common exhaust channel, and then discharged through the common exhaust channel; the airflow measured by one metering chamber is discharged through an independent exhaust channel connected to the exhaust port of the one metering chamber itself.

23. The gas flow measurement method according to claim 20, characterized in that: Each waist wheel assembly includes a first rotor and a second rotor matched with the first rotor; In each of the waist wheel groups, along the clockwise or counterclockwise direction, among the n first rotors from the first rotor of the first waist wheel group to the first rotor of the nth waist wheel group, the angles of the first rotors of adjacent waist wheel groups relative to the air inlets of the respective metering chambers increase gradually with a predetermined angle gradient; wherein the first rotor of each waist wheel group is a rotor in the same installation sequence along the clockwise or counterclockwise direction among the two rotors of each waist wheel group; The predetermined angle gradient is determined according to the following formula: k = 90° / n ±5°; Where k is the predetermined angle gradient; n is the number of waist wheel groups.

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