Heat supply steam pipeline flow metering device

Abstract

The invention relates to the technical field of steam valves, in particular to a heat supply steam pipeline flow metering device which comprises a measuring pipe, a uniform-speed pipe flowmeter, a pipe diameter changing unit arranged on the inner side of the measuring pipe, a plurality of square reducing plates and a driving part. The diameter-variable plates are evenly distributed around the axis of the measuring pipe in the circumferential direction, one side edge of each diameter-variable plate is rotationally connected to the inner wall of the measuring pipe, the pipe diameter changing unit is used for driving the diameter-variable plates to rotate, and when the diameter-variable plates rotate to preset positions, the diameter-variable plates abut against the adjacent diameter-variable plates; the variable-diameter baffle is connected to the end of the variable-diameter plate, abuts against the end of the variable-diameter plate and is used for changing the size of a steam circulation channel along with the variable-diameter plate; a probe tube in the uniform-speed tube flowmeter is positioned in the center of the measuring tube; according to the invention, the steam flow can be measured under the conditions of large pipe diameter and low flow velocity.

Description

Technical Field

[0001] The present invention relates to the technical field of steam valves, and particularly to a flow metering device for a heating steam pipeline. Background Art

[0002] Industrial and civil heating steam needs to be metered and settled, and there is a large peak-valley difference with seasonal changes, user needs, and subsequent development requirements. During the peak steam consumption period, there is a high flow velocity in the pipeline. However, during the low steam consumption period, the steam flow velocity in the pipeline is low.

[0003] Common flow meters used for metering steam usually have two types: vortex flow meters and differential pressure flow meters. Vortex flow meters cannot measure the steam flow in large-diameter pipelines exceeding 300MM, and the pipeline diameters in industrial parks are mostly 600MM. Although differential pressure flow meters can measure the flow of large pipe diameters, during the low steam consumption period, the steam flow velocity in the pipe diameter is slow. When the flow velocity is lower than a certain speed value, the differential pressure flow meter cannot obtain sufficient differential pressure, and thus cannot measure the steam flow. Therefore, this application proposes a flow metering device for a heating steam pipeline. Summary of the Invention

[0004] The purpose of the present invention is to provide a flow metering device for a heating steam pipeline to solve the problem that the current flow meters cannot measure the flow in large-diameter and low-flow-velocity steam pipelines.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A flow metering device for a heating steam pipeline, including a measuring pipe and an averaging pitot tube flow meter. The flow metering device further includes:

[0007] A pipe diameter changing unit provided inside the measuring pipe, including a plurality of square reducing plates and a driving part. The plurality of reducing plates are evenly distributed circumferentially around the axis of the measuring pipe. One side of the reducing plate is rotatably connected to the inner wall of the measuring pipe. The pipe diameter changing unit is used to drive the reducing plate to rotate. When the reducing plate rotates to a preset position, the reducing plate abuts against the adjacent reducing plate;

[0008] A reducing baffle, connected to and abutting against the end of the reducing plate, for changing the size of the steam flow passage following the reducing plate;

[0009] The probe tube in the averaging pitot tube flow meter is located at the center of the measuring pipe.

[0010] Further, the measuring tube includes a middle shell and end caps, the middle shell and the end caps are fixedly connected, the middle shell includes a middle inner shell and a middle outer shell, the middle inner shell and the middle outer shell are concentrically arranged, and the middle outer shell is sleeved outside the middle inner shell. The driving part is located between the middle inner shell and the middle outer shell. The diameter-changing plate is installed on the inner wall of the middle inner shell. A end seat is fixed in the measuring tube. A rotating shaft head is arranged at the end of the diameter-changing plate, and the rotating shaft head is rotatably connected to the end seat.

[0011] Further, the driving part includes:

[0012] A first connecting rod, one end of the first connecting rod is fixedly connected to the rotating shaft head;

[0013] A second connecting rod, the second connecting rod is hinged to the end of the first connecting rod away from the first connecting rod;

[0014] A driving ring, the end of the second connecting rod away from the first connecting rod is hinged to the driving ring, and a plurality of the second connecting rods are all hinged to the driving ring. The driving ring is rotatably connected to the middle inner shell;

[0015] A driving cylinder, the output end of the driving cylinder is hinged to the driving ring, and the end of the driving cylinder away from the driving ring is hinged to the middle inner shell.

[0016] Further, the driving rings at both ends of the middle inner shell are connected by a third connecting rod, and the output end of the driving cylinder is rotatably connected to the third connecting rod.

[0017] Further, the diameter-changing baffle is a T-shaped plate, the edges of adjacent diameter-changing baffles are mutually attached, the diameter-changing baffles are evenly distributed circumferentially around the axis of the measuring tube. Limiting blocks and driving blocks are respectively arranged on both sides of the diameter-changing baffle. The driving block is a cylindrical structure. The diameter-changing baffle is located between the driving plate and the end cap;

[0018] A plurality of limiting grooves along the tangential direction of the end cap opening are arranged on the end cap. The limiting grooves are waist-shaped grooves. A plurality of arc-shaped driving grooves are arranged on the driving plate. One end of the driving groove is close to the inner side wall of the driving plate, and one end is close to the outer side wall of the driving plate. The plurality of limiting grooves and the plurality of driving grooves are both evenly distributed around the axis of the measuring tube. The limiting blocks are slidably connected to the limiting grooves, and the driving blocks are slidably connected to the driving grooves.

[0019] Further, both the end cap and the driving plate are provided with annular sealing grooves on the surface in contact with the diameter-changing baffle, and sealing rings are arranged in the sealing grooves.

[0020] Further, a pressing platform is provided on one side of the variable-diameter baffle where it is connected to the adjacent variable-diameter baffle. The pressing platforms on both sides are respectively located on two sides of the variable-diameter baffle, enabling the variable-diameter baffle to be staggered and pressed on the adjacent pressing platforms.

[0021] Further, the averaging pitot tube flowmeter includes:

[0022] A probe tube, which is diamond-shaped. Parallel pore-shaped pressure measurement cavities are provided inside the probe tube. Both ends of the pressure measurement cavity are blocked, and communication holes are provided on the pressure measurement cavity.

[0023] Two pressure guiding pipes are provided. The two pressure guiding pipes are respectively located at both ends of the probe tube, and the two pressure guiding pipes are respectively communicated with one pressure measurement cavity. The pressure guiding pipes penetrate through the pipe wall on the end cover.

[0024] A differential pressure gauge, and two pressure measurement ports of the differential pressure gauge are respectively connected to different pressure guiding pipes.

[0025] Further, a condensation tank is also provided between the pressure guiding pipe and the differential pressure gauge. The condensation tank is cylindrical and tubular, and the condensation tank is connected to the pressure guiding pipe and the differential pressure gauge through pipe interfaces.

[0026] Further, a control valve is also provided on the pressure guiding pipe for closing the pressure guiding pipe.

[0027] In summary, the present invention has the following beneficial effects compared with the prior art:

[0028] The heat supply steam pipeline flow measurement device disclosed in the embodiment of the present invention installs the averaging pitot tube flowmeter in a pipeline structure with a variable inner diameter. When measuring the steam flow during the low steam consumption period, the steam flow rate is increased by reducing the inner diameter, so as to meet the measurement requirements of the averaging pitot tube flowmeter. After the measurement is completed, the inner diameter returns to its original state, enabling the flow measurement device to measure the steam flow in a state of a large pipe diameter and a low flow rate. Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the overall structure of the heat supply steam pipeline flow measurement device disclosed in the embodiment of the present invention.

[0030] Figure 2 It is Figure 1 the front view of

[0031] Figure 3 It is Figure 2 the sectional view taken along A-A in

[0032] Figure 4Schematic diagram of some parts between the inner middle shell and the outer middle shell of the heating steam pipeline flow metering device disclosed in the embodiment of the present invention.

[0033] Figure 5 Schematic diagram of the structure of the middle pipe diameter changing unit of the heating steam pipeline flow metering device disclosed in the embodiment of the present invention.

[0034] Figure 6 Schematic diagram of the structure of the middle end cover of the heating steam pipeline flow metering device disclosed in the embodiment of the present invention.

[0035] Figure 7 Schematic diagram of the structure of the middle reducing baffle of the heating steam pipeline flow metering device disclosed in the embodiment of the present invention.

[0036] Figure 8 Schematic diagram of the structure of the middle pitot tube flowmeter of the heating steam pipeline flow metering device disclosed in the embodiment of the present invention.

[0037] Reference numerals:

[0038] 100, measuring tube; 110, middle shell; 111, inner middle shell; 112, outer middle shell; 113, end seat; 120, end cover; 121, first flange; 122, second flange; 123, limiting groove; 130, driving plate; 131, driving groove;

[0039] 200, pipe diameter changing unit; 210, reducing plate; 211, mounting head; 212, rotating shaft head; 220, driving part; 221, first connecting rod; 222, second connecting rod; 223, driving ring; 224, driving cylinder; 225, third connecting rod;

[0040] 300, reducing baffle; 301, limiting block; 302, driving block; 303, pressing table;

[0041] 400, pitot tube flowmeter; 410, probe tube; 411, pressure measuring chamber; 412, communication hole; 420, pressure guiding tube; 421, conduit part; 422, connecting elbow; 423, connecting fixed tube; 430, condensation tank; 440, differential pressure gauge; 450, control valve. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] As Figures 1 to 3As shown, a flow metering device for a heating steam pipeline provided by an embodiment of the present invention, the flow metering device includes:

[0044] A measuring pipe 100;

[0045] A pipe diameter changing unit 200, the pipe diameter changing unit 200 is arranged inside the measuring pipe 100, the pipe diameter changing unit 200 includes a plurality of square diameter-changing plates 210 and a driving part 220, the plurality of diameter-changing plates 210 are evenly distributed circumferentially around the axis of the measuring pipe 100, one side edge of the diameter-changing plate 210 is rotatably connected to the inner wall of the measuring pipe 100, the pipe diameter changing unit 200 is used to drive the diameter-changing plate 210 to rotate, and one side edge of the diameter-changing plate 210 facing away from the inner wall of the measuring pipe 100 can abut against the adjacent diameter-changing plate 210 when rotated to a preset position;

[0046] A diameter-changing baffle 300, the diameter-changing baffle 300 is connected to the end of the diameter-changing plate 210 and abuts against the end of the diameter-changing plate 210, and is used to change the size of the steam flow passage following the diameter-changing plate 210;

[0047] An averaging pitot tube flowmeter 400, the averaging pitot tube flowmeter 400 includes a probe tube 410, a pressure guiding tube 420 and a differential pressure gauge 440, the probe tube 410 is located at the center of the measuring pipe 100, the pressure guiding tube 420 passes through the pipe wall of the measuring pipe 100 from a position near the end of the measuring pipe 100 and connects the probe tube 410 and the differential pressure gauge 440, and the differential pressure gauge 440 is fixedly connected to the outside of the measuring pipe 100.

[0048] In this embodiment, when measuring the flow rate, the flow metering device disclosed in the present application has two measurement methods. When it is the peak steam usage period, the flow rate of the steam meets the measurement requirements of the averaging pitot tube flowmeter 400. The variable diameter plate 210 rotates to a position where it does not contact the adjacent variable diameter plate 210. At this time, the cross-section of the measuring tube 100 is the cross-sectional area of the tube minus the cross-sectional area of the variable diameter plate 210 and the cross-sectional area of the pressure guiding tube 420. At this time, the averaging pitot tube flowmeter 400 can measure the flow rate of the steam, and thus measure the steam flow. When it is the low steam usage period, the flow rate of the steam is relatively low. At this time, the driving part 220 drives the variable diameter plate 210 to rotate. When the variable diameter plate 210 rotates, one side away from the inner wall of the measuring tube 100 abuts against the adjacent variable diameter plate 210. At this time, the variable diameter plates 210 form a steam flow channel, and the diameter of the variable diameter baffle 300 decreases. Since the end of the variable diameter baffle 300 abuts against the variable diameter plate 210, the steam cannot enter between the adjacent variable diameter plates 210. Then, the variable diameter baffle 300 and the variable diameter plate 210 form a steam flow channel with a diameter smaller than the inner diameter of the measuring tube 100. At this time, the flow channel of the steam entering the measuring tube 100 becomes smaller. According to Bernoulli's principle, the flow rate of the steam in the measuring tube 100 increases, so that during the low steam usage period, the flow rate of the steam in the measuring tube 100 meets the measurement requirements of the averaging pitot tube flowmeter 400. After the measurement is completed, the variable diameter plate 210 and the variable diameter baffle 300 return to their original states, so that the steam still flows in its original state, thereby reducing the pressure difference loss.

[0049] The heat supply steam pipeline flow metering device disclosed in the embodiment of the present invention installs the averaging pitot tube flowmeter 400 in a pipeline structure with a variable inner diameter. When measuring the steam flow during the low steam usage period, the steam flow rate is increased by reducing the inner diameter, so as to meet the measurement requirements of the averaging pitot tube flowmeter 400. After the measurement is completed, the inner diameter returns to its original state, so that the flow metering device can measure the steam flow in a state of a large pipe diameter and a low flow rate.

[0050] Specifically, as Figure 3 shown, in this embodiment, the measuring tube 100 includes a middle shell 110 and an end cover 120. The middle shell 110 and the end cover 120 are connected by bolts, and the end cover 120 is fixedly connected to the port of the middle shell 110.

[0051] As a preferred implementation manner in this embodiment, the middle shell 110 includes a middle inner shell 111 and a middle outer shell 112. The middle inner shell 111 and the middle outer shell 112 are concentrically arranged, and the middle outer shell 112 is sleeved outside the middle inner shell 111. The driving part 220 is located between the middle inner shell 111 and the middle outer shell 112. The diameter-changing plate 210 is installed on the inner wall of the middle inner shell 111. The middle inner shell 111 and the middle outer shell 112 are connected by screws, that is, the outer side of the middle inner shell 111 is provided with mounting posts with threaded holes, and the fastening screws pass through the middle outer shell 112 and are fixed to the mounting posts.

[0052] In this embodiment, as Figure 3 and Figure 5 shown, the diameter-changing plate 210 is installed on the inner wall of the middle inner shell 111 through the mounting head 211. The mounting head 211 is a cylindrical structure. The mounting head 211 is provided with strip-shaped mounting blocks, and the mounting blocks are provided with strip-shaped grooves. The pipe diameter changing unit 200 is embedded in the mounting blocks on the mounting head 211. The pipe diameter changing unit 200 and the mounting head 211 are connected by screws. Both ends of the middle inner shell 111 are also provided with end seats 113. The end seats 113 are stepped pipes. The end seats 113 are sleeved on the ends of the middle inner shell 111. The end seats 113 and the middle inner shell 111 are fixedly connected by welding. Both ends of the mounting head 211 are provided with rotating shaft heads 212. The rotating shaft heads 212 pass through the end seats 113 and are arranged outside the end seats 113. The pipe diameter changing unit 200 is parallel to the axis of the measuring pipe 100. The driving part 220 is connected to the rotating shaft head 212;

[0053] As Figure 5 shown, the driving part 220 includes a first connecting rod 221, a second connecting rod 222, a driving ring 223 and a driving cylinder 224. One end of the first connecting rod 221 is fixedly connected to the rotating shaft head 212. The second connecting rod 222 and the end of the first connecting rod 221 away from the first connecting rod 221 are hinged. The end of the second connecting rod 222 away from the first connecting rod 221 is hinged to the driving ring 223. A plurality of the second connecting rods 222 are all hinged to the driving ring 223. The driving ring 223 is rotatably connected to the middle inner shell 111. The driving cylinder 224 is a pneumatic cylinder. The driving cylinder 224 is driven by steam pressure. The output end of the driving cylinder 224 is hinged to the driving ring 223. The end of the driving cylinder 224 away from the driving ring 223 is hinged to the middle inner shell 111. When the driving cylinder 224 expands and contracts, it drives the driving ring 223 to rotate, thereby driving the rotating shaft head 212 to rotate through the second connecting rod 222 and the first connecting rod 221, and further driving the pipe diameter changing unit 200 to rotate.

[0054] Preferably, in this embodiment, the drive rings 223 at both ends of the middle inner shell 111 are connected by a third connecting rod 225. Threaded holes are provided at both ends of the third connecting rod 225. The third connecting rod 225 is threadedly connected to the pin shafts on the drive rings 223. The output end of the drive cylinder 224 is rotatably connected to the third connecting rod 225.

[0055] In this embodiment, a drive plate 130 is rotatably connected to the inner side of the end cover 120. The drive ring 223 is fixedly connected to the drive plate 130. The end cover 120 limits the drive plate 130 through a stepped structure. The drive plate 130 is annular. The drive ring 223 and the drive plate 130 are concentrically arranged and are of an integral structure.

[0056] As a preferred implementation manner in this embodiment, as Figure 4 、 Figure 6 and Figure 7 shown, the variable diameter baffle 300 is a T-shaped plate. The edges of adjacent variable diameter baffles 300 are in mutual contact. The variable diameter baffles 300 are evenly distributed circumferentially around the axis of the measuring tube 100. Limiting blocks 301 and driving blocks 302 are respectively arranged on both sides of the variable diameter baffle 300. The limiting block 301 is a kidney-shaped block. The driving block 302 is a cylindrical structure. The variable diameter baffle 300 is located between the drive plate 130 and the end cover 120. A plurality of limiting grooves 123 are provided on the end cover 120 along the tangential direction of the mouth of the end cover 120. The limiting grooves 123 are kidney-shaped grooves. A plurality of arc-shaped driving grooves 131 are provided on the drive plate 130. One end of the driving groove 131 is close to the inner side wall of the drive plate 130, and one end is close to the outer side wall of the drive plate 130. The plurality of limiting grooves 123 and the plurality of driving grooves 131 are both evenly distributed around the axis of the measuring tube 100. The limiting block 301 is slidably connected to the limiting groove 123. The driving block 302 is slidably connected to the driving groove 131. When the drive plate 130 rotates, the drive plate 130 drives the variable diameter baffle 300 to slide along the limiting groove 123. When the variable diameter baffle 300 slides to the end of the limiting groove 123 close to the edge, the mouth formed by the variable diameter baffle 300 becomes larger. When the variable diameter baffle 300 slides to the end close to the center position, the mouth formed by the variable diameter baffle 300 becomes smaller.

[0057] As a preferred implementation manner in this embodiment, both the end cover 120 and the drive plate 130 are provided with annular sealing grooves on the side in contact with the variable diameter baffle 300, and sealing rings are arranged in the sealing grooves.

[0058] As a preferred implementation mode in this embodiment, a pressing platform 303 is provided on one side of the variable-diameter baffle 300 connected to the adjacent variable-diameter baffle 300. The two pressing platforms 303 are respectively located on two sides of the variable-diameter baffle 300, so that the variable-diameter baffle 300 can be staggered and pressed on the adjacent pressing platforms 303, thereby improving the sealing performance between the variable-diameter baffles 300 and reducing the penetration of steam.

[0059] In this embodiment, the driving part 220 is between the middle inner shell 111 and the middle outer shell 112. The end cover 120 is circular tubular. End plate structures are provided at both ends of the end cover 120. The outer diameter of the end plate at one end of the end cover 120 connected to the measuring tube 100 is larger than that of the end plate at the other end of the end cover 120. A first flange 121 and a limiting groove 123 are respectively provided at both ends of the end cover 120. The first flange 121 is used to connect the steam pipeline, and the second flange 122 is used to connect the middle outer shell 112.

[0060] As a preferred implementation mode in this embodiment, as Figure 3 and Figure 8 shown, the averaging pitot tube flowmeter 400 includes a probe tube 410, a pressure guiding tube 420, and a differential pressure gauge 440. The probe tube 410 is diamond-shaped. Parallel hole-shaped pressure measuring cavities 411 are provided in the probe tube 410. Both ends of the pressure measuring cavity 411 are blocked. Communication holes 412 are provided on the pressure measuring cavity 411. Two pressure guiding tubes 420 are provided. The two pressure guiding tubes 420 are respectively located at both ends of the probe tube 410, and the two pressure guiding tubes 420 are respectively communicated with one pressure measuring cavity 411. The pressure guiding tubes 420 pass through the tube wall on the end cover 120. The two pressure measuring ports of the differential pressure gauge 440 are respectively connected to different pressure guiding tubes 420. When measuring the pressure, the communication holes 412 on both sides of the probe tube 410 are respectively located upstream and downstream of the steam.

[0061] Specifically, the pressure guiding tube 420 includes a conduit part 421, a connecting elbow 422, and a connecting fixing tube 423. The conduit part 421 is connected to the probe tube 410. The connecting fixing tube 423 is embedded in the end cover 120 by welding. Both ends of the connecting elbow 422 are fixed to the conduit part 421 and the connecting fixing tube 423 through nuts.

[0062] Preferably, a condensate tank 430 is further provided between the pressure guiding tube 420 and the differential pressure gauge 440. The condensate tank 430 is cylindrical tubular. The condensate tank 430 is connected to the pressure guiding tube 420 and the differential pressure gauge 440 through pipe interfaces. The condensate tank 430 can prevent the generation of bubbles and the superposition of damping.

[0063] The differential pressure gauge 440 is of the prior art.

[0064] Preferably, in this embodiment, a control valve 450 is further provided on the pressure guiding pipe 420 for closing the pressure guiding pipe 420.

[0065] The terms used in the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. The singular forms "a", "the" and "said" used in the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0066] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0067] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flow measurement device for a heat supply steam pipeline, comprising a measuring pipe and an averaging pitot tube flowmeter, characterized in that, The flow metering device further includes: A pipe diameter changing unit disposed inside the measuring pipe, including a plurality of square diameter-changing plates and a driving part. The plurality of diameter-changing plates are evenly distributed circumferentially around the axis of the measuring pipe. One side edge of the diameter-changing plate is rotatably connected to the inner wall of the measuring pipe. The pipe diameter changing unit is used to drive the diameter-changing plate to rotate. When the diameter-changing plate rotates to a preset position, the diameter-changing plate abuts against the adjacent diameter-changing plate; A diameter-changing baffle, which is connected to and abuts against the end of the diameter-changing plate, and is used to follow the diameter-changing plate to change the size of the steam flow passage; The probe tube in the averaging pitot tube flowmeter is located at the center of the measuring pipe.

2. The flow metering device for the heating steam pipeline according to claim 1, wherein The measuring pipe includes a middle shell and end caps. The middle shell and the end caps are fixedly connected. The middle shell includes a middle inner shell and a middle outer shell. The middle inner shell and the middle outer shell are concentrically arranged, and the middle outer shell is sleeved outside the middle inner shell. The driving part is located between the middle inner shell and the middle outer shell. The diameter-changing plate is installed on the inner wall of the middle inner shell. A end seat is fixed in the measuring pipe. A rotating shaft head is arranged at the end of the diameter-changing plate, and the rotating shaft head is rotatably connected to the end seat.

3. The flow metering device for a heating steam pipeline according to claim 2, wherein The driving part includes: A first connecting rod, one end of which is fixedly connected to the rotating shaft head; A second connecting rod, which is hinged to the end of the first connecting rod away from the first connecting rod; A driving ring, the end of the second connecting rod away from the first connecting rod is hinged to the driving ring, and the plurality of second connecting rods are all hinged to the driving ring. The driving ring is rotatably connected to the middle inner shell; A driving cylinder, the output end of which is hinged to the driving ring, and the end of the driving cylinder away from the driving ring is hinged to the middle inner shell.

4. The flow metering device for a heating steam pipeline according to claim 3, wherein The driving rings at both ends of the middle inner shell are connected by a third connecting rod, and the output end of the driving cylinder is rotatably connected to the third connecting rod.

5. The flow metering device for a heating steam pipeline according to any one of claims 2-4, wherein The diameter-changing baffle is a T-shaped plate, the edges of adjacent diameter-changing baffles are mutually attached, the diameter-changing baffles are evenly distributed circumferentially around the axis of the measuring pipe, and a limiting block and a driving block are respectively arranged on both sides of the diameter-changing baffle. The driving block is a cylindrical structure, and the diameter-changing baffle is located between the driving plate and the end cap; A plurality of limiting grooves along the tangential direction of the end cap opening are arranged on the end cap. The limiting grooves are kidney-shaped grooves. A plurality of arc-shaped driving grooves are arranged on the driving plate. One end of the driving groove is close to the inner side wall of the driving plate, and one end is close to the outer side wall of the driving plate. The plurality of limiting grooves and the plurality of driving grooves are all evenly distributed around the axis of the measuring pipe. The limiting block is slidably connected to the limiting groove, and the driving block is slidably connected to the driving groove.

6. The flow metering device for the heating steam pipeline according to claim 5, wherein Both the end cap and the driving plate are provided with annular sealing grooves on the surface in contact with the diameter-changing baffle, and sealing rings are arranged in the sealing grooves.

7. The flow metering device for a heat supply steam pipeline according to claim 5, wherein, One side of the variable-diameter baffle plate connected to the adjacent variable-diameter baffle plate is provided with a pressing platform, and the two pressing platforms are respectively located on two sides of the variable-diameter baffle plate, so that the variable-diameter baffle plates can be staggered and pressed on the adjacent pressing platforms.

8. The flow metering device for a heating steam pipeline according to any one of claims 2-4, characterized in that, The averaging pitot tube flowmeter includes: A probe tube, the probe tube is diamond-shaped, and parallel hole-shaped pressure measurement cavities are arranged inside the probe tube. Both ends of the pressure measurement cavity are blocked, and communication holes are arranged on the pressure measurement cavity; Pressure guiding pipes, there are two pressure guiding pipes, the two pressure guiding pipes are respectively located at both ends of the probe tube, and the two pressure guiding pipes are respectively communicated with one pressure measurement cavity, and the pressure guiding pipes penetrate through the pipe wall on the end cover; A differential pressure gauge, and the two pressure measurement ports of the differential pressure gauge are respectively connected to different pressure guiding pipes.

9. The flow metering device for a heating steam pipeline according to claim 8, characterized in that, A condensate tank is further arranged between the pressure guiding pipe and the differential pressure gauge. The condensate tank is cylindrical tubular, and the condensate tank is connected to the pressure guiding pipe and the differential pressure gauge through pipe interfaces.

10. The flow metering device for a heating steam pipeline according to claim 8, characterized in that, A control valve is further arranged on the pressure guiding pipe for closing the pressure guiding pipe.

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