A ring cavity pressure differential flowmeter

Abstract

The present invention relates to the technical field of differential pressure flowmeters, specifically to an annular cavity pressure-taking differential pressure flowmeter, comprising a pressure-bearing tube body, a throttling member, and two inner sleeves sleeved in the pressure-bearing tube body, wherein a first annular groove, a positioning structure, and a second annular groove are sequentially formed on the inner hole of the pressure-bearing tube body along the conveying direction of the fluid medium; the inner hole diameter of the positioning structure is not larger than the diameter of the inner hole of the pressure-bearing tube body; the two inner sleeves are fixedly connected to the pressure-bearing tube body, and the outer circumferential surfaces of the inner sleeves are matched with the inner hole of the pressure-bearing tube body, and the two inner sleeves are respectively arranged on both sides of the positioning structure, for respectively covering the notch of the first annular groove and the notch of the second annular groove; forming a first annular cavity and a second annular cavity; the first annular cavity is connected to the inner cavity of the inner sleeve on the same side, and the second annular cavity is connected to the inner cavity of the inner sleeve on the same side; the upstream pressure measuring device is connected to the first annular cavity, and the downstream pressure measuring device is connected to the second annular cavity.

Description

Technical Field

[0001] The invention relates to the technical field of differential pressure flowmeters, in particular to an annular cavity pressure-taking type differential pressure flowmeter. Background Art

[0002] A differential pressure flowmeter is an instrument for measuring flow. It uses the principle that there is a certain relationship between the pressure difference generated when a fluid flows through a throttling device and the flow rate, and measures the flow rate by measuring the pressure difference. A throttling device is a local contraction element installed in a pipeline. Depending on the type of throttling device, differential pressure flowmeters are usually divided into orifice flowmeters, nozzle flowmeters, and Venturi tube flowmeters. Based on the different pressure measurement methods, differential pressure flowmeters can also be divided into borehole pressure differential pressure flowmeters, annular cavity pressure differential flowmeters (also known as annular chamber pressure differential flowmeters), flange pressure differential pressure flowmeters, and DD / 2 pressure differential pressure flowmeters.

[0003] Among them, the annular cavity pressure differential flowmeter is widely used in various pipeline fields (especially in pipelines that transport dirty media such as steam, gas and cooling water) because it is not easy to clog the pressure hole, has a simple geometric shape, can be precisely processed and assembled, is easy to improve measurement accuracy, and does not require long straight pipes for installation.

[0004] However, the existing annular cavity pressure differential flowmeter usually divides the pressure pipe into two sections, the front and rear sections, and the throttling piece is clamped by the front and rear sections. The connection between the front and rear sections is usually achieved in the following two ways: (1) the front and rear sections are connected by welding to form a circumferential butt weld; (2) flanges are respectively installed on the front and rear sections, and the two flanges clamp the throttling piece (seals are installed on both sides of the throttle) and then connected by bolts to achieve the purpose of fixing the throttling piece and sealing. Among them, the circumferential butt weld of method (1) cannot achieve full penetration welding of the pressure pipe, and the weld joint has serious stress. The method (2) has the risk of leakage due to unreliable sealing between the flange and the throttling piece, and the flange connection structure will increase the radial and axial dimensions of the annular cavity pressure differential pressure flowmeter, occupying a large installation space and significantly increasing the manufacturing cost. This makes the existing annular cavity pressure differential pressure flowmeters usually have complex processing technology and assembly procedures, occupy a large space, have a long production cycle, high production costs, and high safety risks. Summary of the Invention

[0005] In order to solve the defects of the above-mentioned prior art, the present invention provides an annular cavity pressure-taking differential pressure flowmeter to solve the problems of the existing annular cavity pressure-taking differential pressure flowmeter, which usually has complex processing technology and assembly procedures, large space occupation, long production cycle, high production cost and high safety risk.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] An annular cavity pressure differential flowmeter comprises a pressure-bearing tube body, a throttling member, and two inner sleeves sleeved within the pressure-bearing tube body. The pressure-bearing tube body is used to convey a fluid medium. The pressure-bearing tube body is integrally formed. A first annular groove, a positioning structure, and a second annular groove are sequentially formed on the inner hole of the pressure-bearing tube body along the conveying direction of the fluid medium.

[0008] The first annular groove and the second annular groove are both formed along the circumference of the pressure-bearing tube body. The positioning structure is annular and coaxial with the pressure-bearing tube body. The diameter of the inner hole of the positioning structure is no larger than the diameter of the inner hole of the pressure-bearing tube body. The throttle member is assembled in the positioning structure and fixedly connected to the positioning structure. The outer circumferential surface of the throttle member cooperates with the inner circumferential surface of the positioning structure.

[0009] The two inner sleeves are both fixedly connected to the pressure-bearing pipe body, and the outer circumferential surfaces of the inner sleeves are matched with the inner holes of the pressure-bearing pipe body. The two inner sleeves are respectively arranged on both sides of the positioning structure, and are used to respectively cover the notches of the first annular groove and the second annular groove; so as to form a first annular cavity between the first annular groove and the inner sleeve on the same side, and a second annular cavity between the second annular groove and the inner sleeve on the same side; the inner sleeves are both provided with flow channels; the two flow channels are respectively used to connect the first annular cavity with the inner cavity of the inner sleeve on the same side, and to connect the second annular cavity with the inner cavity of the inner sleeve on the same side;

[0010] The pressure-bearing pipe body is provided with two through holes, one of which is used to connect the first annular cavity and the upstream pressure measuring device, and the other through hole is used to connect the second annular cavity and the downstream pressure measuring device.

[0011] The throttling member is used to connect the inner cavities of the two inner sleeves and form a pressure difference between the inner cavities of the two inner sleeves.

[0012] In the above technical solution, since the pressure-bearing pipe body is integrally formed as a whole, the structure avoids the existing annular cavity pressure differential pressure flowmeter in which the pressure-bearing pipe body is divided into a front and a rear pipe body, thereby avoiding the technical problems caused by the connection of the front and rear pipe bodies (such as: the front and rear pipe bodies are welded together to form a circumferential butt weld; since the circumferential butt weld cannot achieve full penetration welding of the pressure-bearing pipe body, there is serious stress concentration in the weld joint, and the volume non-destructive testing of the weld cannot be achieved, the circumferential butt weld is difficult to meet the requirements of the pressure pipeline safety technical specifications, and there is a major safety hazard; or flanges are respectively installed on the front and rear pipe bodies, the two flanges clamp the throttle element, and seals are installed on both sides of the throttle and then connected by bolts, there is a risk of leakage between the flange and the throttle element due to unreliable sealing, and the flange connection structure will increase the radial and axial dimensions of the annular cavity pressure differential pressure flowmeter, occupy a larger installation space, and significantly increase the manufacturing cost).

[0013] In the above technical solution, since the pressure-bearing pipe body is integrally formed without annular butt welds, there is no concern about insufficient load-bearing capacity of incomplete welds, stress concentration, and inability to achieve volume non-destructive testing; compared with the flange connection structure, there is no concern about sealing surface leakage, and the geometric dimensions are compact, the processing technology is simple, and the manufacturing and installation costs are low; it solves the technical problems of existing annular cavity pressure differential flowmeters that usually have complex processing technology and assembly procedures, large space occupation, long production cycle, high production cost, and high safety risks.

[0014] Furthermore, one end of the inner sleeve away from the positioning structure is welded to the inner hole of the pressure-bearing pipe body.

[0015] Since the welding seam between the inner sleeve and the inner hole of the pressure-bearing pipe body is a non-pressure-bearing weld seam, it will not cause safety hazards.

[0016] Furthermore, the positioning structure is an annular protrusion integrally formed on the inner hole of the pressure-bearing pipe body.

[0017] By setting the positioning structure as an annular protrusion integrally formed on the inner hole of the pressure-bearing tube body, the positioning structure can be processed together during the processing of the inner hole of the pressure-bearing tube body, without the need to set the positioning structure as an additional assembly component, reducing the processing steps of fixing the positioning structure to the pressure-bearing tube body and saving assembly time.

[0018] In another technical solution, an annular groove is opened circumferentially on the inner hole of the pressure-bearing tube body, and the positioning structure is an annular component fixedly connected to the annular groove. The outer circumferential surface of the annular component cooperates with the bottom of the annular groove, and the annular component is used to separate the annular groove into the first annular groove and the second annular groove.

[0019] The above technical solution is based on the consideration of maximizing the thickness of the seamless steel pipe used for pressure bearing when the pressure-bearing pipe body is manufactured from finished seamless steel pipe. In this solution, the positioning structure is manufactured separately from the pressure-bearing pipe body. The first and second annular grooves machined on the inner surface of the pressure-bearing pipe body are combined into a single annular groove. The positioning structure is installed in the middle of the annular groove of the pressure-bearing pipe body and fits into the gap between the annular grooves.

[0020] Based on the assembly accessibility requirements of the positioning structure, the positioning structure cannot be a whole and must be divided into at least three arc-shaped parts. The maximum distance between any two points on the radial cross-section of each arc-shaped part is less than the inner diameter of the pressure pipe body.

[0021] Furthermore, at least one protrusion is provided on the bottom of the annular groove, and the protrusion is used to abut against a side of the annular component facing the output side of the fluid medium.

[0022] By providing the raised portion, the raised portion is abutted against the side of the annular member facing the output side of the fluid medium, so that when the annular member (that is, the positioning structure) and the throttling member jointly bear the impact in the flow direction of the fluid medium, the raised portion can support the annular member, thereby reducing the force on the fixed connection between the annular member and the pressure-bearing pipe body, and protecting the fixed connection between the annular member and the pressure-bearing pipe body.

[0023] Furthermore, the number of the protrusion is one, the protrusion is annular, and extends along the circumference of the annular groove.

[0024] In another technical solution, there are multiple protrusions, and the multiple protrusions are arranged at intervals along the circumference of the annular groove.

[0025] Furthermore, the annular cavity pressure-taking differential pressure flowmeter also includes a plurality of clamping strips, each of which is arranged at the bottom of the first annular groove, and each of which is evenly distributed along the circumference of the first annular groove. Each of which has one end abutting against the side of the first annular groove away from the positioning structure, and the other end abutting against the positioning structure.

[0026] Furthermore, the annular component includes at least three identical arc-shaped parts, and the arc-shaped parts are sequentially connected end to end along the circumference of the pressure-bearing pipe body to form a circular ring.

[0027] Furthermore, a male stop is provided on the side of the inner hole of the positioning structure close to the output side of the fluid medium of the pressure-bearing tube body, and a female stop is provided on the outer peripheral surface of the throttling member close to the output side of the fluid medium of the pressure-bearing tube body to match the male stop.

[0028] By setting the male stop and the female stop, when the throttling member is subjected to the impact in the flow direction of the fluid medium, the positioning structure can support the throttling member through the cooperation and limitation of the male stop and the female stop, so as to reduce the force on the fixed connection between the throttling member and the positioning structure, and protect the fixed connection between the throttling member and the positioning structure.

[0029] Furthermore, the inner diameter of the positioning structure is larger than the inner diameter of the inner sleeve; the inner sleeve for covering the first annular groove presses against the throttling member at one end toward the positioning structure to make the female stop and the male stop fit tightly.

[0030] By making the inner sleeve for covering the first annular groove press against the throttling member at one end toward the positioning structure so that the female stop and the male stop fit tightly together, the fixation between the throttling member and the positioning structure can be completed without setting other fixed connections (such as welding connections, bolt connections, etc.) between the throttling member and the positioning structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 1 is a structural cross-sectional view of the annular cavity pressure differential pressure flowmeter in Example 1;

[0033] Figure 2 yes Figure 1 A partial enlarged view of area A in the middle;

[0034] Figure 3 This is a front view of the structure of the inner sleeve in Example 1;

[0035] Figure 4 This is a left side view of the structure of the inner sleeve in Example 1;

[0036] Figure 5 is a structural diagram of the positioning structure in Example 1;

[0037] Figure 6This is a schematic structural diagram corresponding to area A in Example 2;

[0038] Figure 7 This is a schematic structural diagram corresponding to area A in Example 3;

[0039] Figure 8 This is a schematic structural diagram corresponding to region A in Example 4;

[0040] Figure 9 This is a schematic structural diagram corresponding to region A in Example 5;

[0041] Figure 10 is a structural cross-sectional view of the annular cavity pressure differential pressure flowmeter in Example 6;

[0042] Figure 11 is a structural cross-sectional view of the annular cavity pressure differential pressure flowmeter in Example 7;

[0043] Figure 12 is a structural cross-sectional view of the annular cavity pressure differential flowmeter in Example 8;

[0044] Figure 13 yes Figure 12 A partial enlarged view of the middle B area;

[0045] Figure 14 This is a front view of the structure of the inner sleeve for shielding the first annular groove in Example 8;

[0046] Figure 15 This is a right side view of the structure of the inner sleeve for shielding the first annular groove in Example 8;

[0047] Figure 16 This is a front view of the structure of the inner sleeve for shielding the first annular groove in Example 9;

[0048] Figure 17 This is a right side view of the structure of the inner sleeve for shielding the first annular groove in Example 9;

[0049] Among them, 1-pressure pipe body, 2-throttling device, 3-inner sleeve, 4-first annular cavity, 5-second annular cavity, 6-upstream pressure measuring device, 7-downstream pressure measuring device, 8-pin shaft, 9-positioning structure

[0050] 11—first annular groove, 12—second annular groove, 13—through hole;

[0051] 91—arc-shaped piece;

[0052] 31—flow slot, 32—flow hole. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0054] Example 1:

[0055] like Figure 1 、 Figure 2 As shown, this embodiment 1 provides an annular cavity pressure differential pressure flowmeter, comprising a pressure-bearing tube body 1, a throttling member 2, and two inner sleeves 3 sleeved within the pressure-bearing tube body 1. The pressure-bearing tube body 1 is used to convey a fluid medium. The pressure-bearing tube body 1 is integrally formed. A first annular groove 11, a positioning structure 9, and a second annular groove 12 are sequentially formed on the inner hole of the pressure-bearing tube body 1 along the conveying direction of the fluid medium.

[0056] The first annular groove 11 and the second annular groove 12 are both opened along the circumference of the pressure-bearing pipe body 1. The positioning structure 9 is annular and coaxial with the pressure-bearing pipe body 1. The inner diameter of the positioning structure 9 is not larger than the diameter of the inner hole of the pressure-bearing pipe body 1. The throttle member 2 is assembled in the positioning structure 9 and is fixedly connected to the positioning structure 9. The outer circumferential surface of the throttle member 2 is matched with the inner circumferential surface of the positioning structure 9.

[0057] The two inner sleeves 3 are fixedly connected to the pressure-bearing pipe body 1, and the outer circumferential surfaces of the inner sleeves 3 are matched with the inner holes of the pressure-bearing pipe body 1. The two inner sleeves 3 are respectively arranged on both sides of the positioning structure 9, and are used to respectively cover the notches of the first annular groove 11 and the second annular groove 12; so as to form a first annular cavity 4 between the first annular groove 11 and the inner sleeve 3 on the same side, and a second annular cavity 5 between the second annular groove 12 and the inner sleeve 3 on the same side; each inner sleeve 3 is provided with a flow channel; the two flow channels are respectively used to connect the first annular cavity 4 with the inner cavity of the inner sleeve 3 on the same side, and to connect the second annular cavity 5 with the inner cavity of the inner sleeve 3 on the same side;

[0058] The throttling member 2 is provided with a second flow port for communicating the inner cavities of the two inner sleeves 3;

[0059] Two through holes 13 are formed on the pressure-bearing pipe body 1 , one of the through holes 13 is used to connect the first annular cavity 4 with the upstream pressure measuring device 6 , and the other through hole 13 is used to connect the second annular cavity 5 with the downstream pressure measuring device 7 .

[0060] In the above technical solution, since the pressure-bearing pipe body 1 is integrally formed as a whole, the structure avoids the division of the pressure-bearing pipe body 1 into two sections, front and rear, in the existing annular cavity pressure differential pressure flowmeter, thereby avoiding the technical problems caused by the connection of the front and rear sections (such as: the front and rear sections are welded together to form a circumferential butt weld; since the circumferential butt weld cannot achieve full penetration welding of the pressure-bearing pipe body 1, there is serious stress concentration in the weld joint, and the volume non-destructive testing of the weld cannot be achieved, the circumferential butt weld is difficult to meet the requirements of the pressure pipeline safety technical specifications, and there is a major safety hazard; or flanges are respectively installed on the front and rear sections of the pipe body, the two flanges clamp the throttle device 2, and seals are installed on both sides of the throttle and connected by bolts, there is a risk of leakage between the flange and the throttle device 2 due to unreliable sealing, and the flange connection structure will increase the radial and axial dimensions of the annular cavity pressure differential pressure flowmeter, occupy a larger installation space, and the manufacturing cost is also greatly increased).

[0061] In the above technical solution, since the pressure-bearing pipe body 1 is integrally formed without annular butt welds, there is no concern about insufficient bearing capacity of incomplete welds, stress concentration, and inability to achieve volume non-destructive testing; compared with the flange connection structure, there is no concern about sealing surface leakage, and the geometric dimensions are compact, the processing technology is simple, and the manufacturing cost and installation cost are low; it solves the technical problems of existing annular cavity pressure differential flowmeters that usually have complex processing technology and assembly procedures, large space occupation, long production cycle, high production cost, and high safety risks.

[0062] The throttle element 2 may be configured as various types of throttle elements, including but not limited to: an orifice throttle element, a nozzle throttle element, a venturi throttle element, or a conical throttle element.

[0063] In this embodiment 1, the throttling element 2 is a nozzle throttling element.

[0064] In this embodiment 1, Figure 1 As shown, one end of the inner sleeve 3 away from the positioning structure 9 is welded to the inner hole of the pressure-bearing pipe body 1 .

[0065] Among them, there are many ways to implement the technical solution of sequentially forming the first annular groove 11, the positioning structure 9 and the second annular groove 12 on the inner hole of the pressure-bearing pipe body 1 along the conveying direction of the fluid medium, including but not limited to the following solutions:

[0066] Option 1:

[0067] A first annular groove 11 and a second annular groove 12 are sequentially spaced apart on the inner hole of the pressure-bearing pipe body 1 along the conveying direction of the fluid medium, and a positioning structure 9 is formed between the first annular groove 11 and the second annular groove 12; in this scheme one, the positioning mechanism 9 is integrally formed with the inner hole of the pressure-bearing pipe body 1.

[0068] Option 2:

[0069] An annular groove is opened circumferentially on the inner hole of the pressure-bearing pipe body 1. The positioning structure 9 is an annular component fixedly connected in the annular groove. The outer peripheral surface of the positioning structure 9 cooperates with the bottom of the annular groove. The positioning structure 9 is used to separate the annular groove into a first annular groove 11 and a second annular groove 12.

[0070] In this embodiment 1, the arrangement of the first annular groove 11, the positioning structure 9 and the second annular groove 12 adopts the above-mentioned scheme 2;

[0071] like Figure 1 As shown, an annular groove is opened circumferentially on the inner hole of the pressure-bearing pipe body 1, and the positioning structure 9 is an annular component fixedly connected in the annular groove. The outer peripheral surface of the positioning structure 9 cooperates with the bottom of the annular groove. The positioning structure 9 is used to separate the annular groove into a first annular groove 11 and a second annular groove 12.

[0072] If the positioning structure 9 is an integral part, due to structural size limitations (because the outer diameter of the positioning structure 9 is larger than the diameter of the inner hole of the pressure-bearing pipe body 1 ), the positioning structure 9 cannot be installed in the annular groove.

[0073] Therefore, in this embodiment 1, the method for installing the positioning structure 9 into the annular groove includes but is not limited to: dividing the annular member into at least three arc-shaped members, wherein the distance between any two points in the radial cross-section of each arc-shaped member is less than the inner diameter of the pressure-bearing pipe body 1. The curvature of each arc-shaped member can be the same or different.

[0074] In this embodiment 1, Figure 5 As shown, the annular component includes four identical arc-shaped members 91 (if all arc-shaped members 91 are identical, it is sufficient to set at least three), and each arc-shaped member 91 is connected in sequence along the circumference of the pressure-bearing pipe body 1 to form a circular ring.

[0075] There are many ways to implement the fixed connection between the positioning structure 9 and the pressure-bearing pipe body 1, and the fixed connection between the positioning structure 9 and the throttling member 2, such as but not limited to: in this embodiment 1, Figure 2 As shown, each arc-shaped member 91 is sequentially installed in the annular groove to form a circular ring, and then the arc-shaped member 91 is welded to the annular groove, and the inner circumference of the inner hole of the positioning structure 9 is welded to the outer circumference of the throttling member 2.

[0076] Since the first annular cavity 4, the second annular cavity 5 and the corresponding inner cavity of the inner sleeve 3 need to be connected to ensure that the fluid upstream and downstream of the throttling member 2 flows into the first annular cavity and the second annular cavity respectively. In this embodiment 1, this is achieved in the following way:

[0077] Method 1:

[0078] When the inner sleeve 3 is installed, a certain gap is ensured between the inner sleeve 3 and the throttling member 2 to form a flow passage. Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 shown.

[0079] Method 2:

[0080] If the inner sleeve 3 is mounted against the throttle member 2, a flow groove is opened at one end of the inner sleeve 3 close to the throttle member 2, or a flow hole is opened on the inner sleeve 3 to connect the inner cavity of the inner sleeve 3 with the corresponding annular cavity (the first annular cavity 4 or the second annular cavity 5).

[0081] The opening forms of the flow groove include but are not limited to: square groove, V-shaped groove, U-shaped groove, etc.

[0082] The opening forms of the flow holes include but are not limited to: round holes, elliptical holes, waist-shaped holes, etc.

[0083] In this embodiment 1, the communication between the first annular cavity 4, the second annular cavity 5 and the corresponding inner cavity of the inner sleeve 3 is achieved by the above-mentioned method 1.

[0084] Among them, in this embodiment 1, as Figure 2 As shown, a male stop is provided on the side of the inner hole of the positioning structure 9 close to the output side of the fluid medium of the pressure-bearing tube body 1, and a female stop that matches the male stop is provided on the side of the outer peripheral surface of the throttling member 2 close to the output side of the fluid medium of the pressure-bearing tube body 1.

[0085] By setting the male stop and the female stop, when the throttling member 2 is subjected to the impact of the flow direction of the fluid medium, the positioning structure 9 can form support for the throttling member 2 through the cooperation and limitation of the male stop and the female stop, so as to reduce the force on the fixed connection between the throttling member 2 and the positioning structure 9, and form protection for the fixed connection between the throttling member 2 and the positioning structure 9.

[0086] Example 2:

[0087] The structure of the annular cavity pressure differential flowmeter provided in Example 2 is substantially the same as that of Example 1, except that the fixed connection method between the positioning structure 9 and the pressure-bearing pipe body 1 is different;

[0088] like Figure 6 As shown, in this embodiment 2, a pin + plug welding method is used to fix the positioning structure 9 and the pressure-bearing pipe body 1;

[0089] Specifically, a plurality of pin holes are arranged at intervals along the circumferential direction on the pressure-bearing tube body 1, and a pin 8 is arranged in each pin hole. One end of the pin 8 passes through the pressure-bearing tube body 1 and then passes into the positioning structure 9, and the other end of the pin 8 is located in the pin hole and does not pass through the outer circumferential surface of the pressure-bearing tube body. The openings of each pin hole on the outer circumferential surface of the pressure-bearing tube body 1 are closed by plug welding to fix the pin 8 in the corresponding pin hole.

[0090] Example 3:

[0091] The structure of the annular cavity pressure differential flowmeter provided in Example 3 is substantially the same as that of Example 1, except that the fixed connection method between the positioning structure 9 and the pressure-bearing pipe body 1 and the fixed connection method between the positioning structure 9 and the throttling member 2 are different.

[0092] like Figure 7 As shown, in this embodiment 3, the positioning structure 9, the pressure-bearing pipe body 1 and the throttling member 2 are fixedly connected by a pin shaft + plug welding method;

[0093] Specifically, a plurality of pin holes are arranged at intervals along the circumferential direction on the pressure-bearing tube body 1, and a pin 8 is arranged in each pin hole. One end of the pin 8 passes through the pressure-bearing tube body 1 and the positioning structure 9 in sequence and then passes into the throttling member 2. The other end of the pin 8 is located in the pin hole and does not pass through the outer circumferential surface of the pressure-bearing tube body. The openings of each pin hole on the outer circumferential surface of the pressure-bearing tube body 1 are closed by plug welding to fix the pin 8 in the corresponding pin hole.

[0094] Example 4:

[0095] The structure of the annular cavity pressure differential flowmeter provided in Example 4 is substantially the same as that of Example 1, except that the fixed connection method between the positioning structure 9 and the pressure-bearing pipe body 1 is different;

[0096] like Figure 8 As shown, in this embodiment 3, the positioning structure 9, the pressure-bearing pipe body 1 and the throttling member 2 are fixedly connected by a pin + fillet welding method;

[0097] Specifically, a plurality of pin shaft holes are arranged at intervals along the circumferential direction on the pressure-bearing pipe body 1, and a pin shaft 8 is arranged in each pin shaft hole. One end of the pin shaft 8 passes through the pressure-bearing pipe body 1 and then passes into the positioning structure 9, and the other end of the pin shaft 8 passes through the outer peripheral surface of the pressure-bearing pipe body. The end of the pin shaft 8 passing through the outer peripheral surface of the pressure-bearing pipe body is fixedly connected to the outer peripheral surface of the pressure-bearing pipe body 1 by fillet welding to fix the pin shaft 8.

[0098] Example 5:

[0099] The structure of the annular cavity pressure differential flowmeter provided in Example 5 is substantially the same as that in Example 1, except that: in this Example 5, Figure 9As shown, the positioning structure 9 is an annular protrusion integrally formed on the inner hole of the pressure-bearing pipe body 1.

[0100] By setting the positioning structure 9 as an annular protrusion integrally formed on the inner hole of the pressure-bearing pipe body 1, the positioning structure 9 can be processed together during the inner hole processing of the pressure-bearing pipe body 1. There is no need to set the positioning structure 9 as an additional assembly component, which reduces the processing steps of fixing the positioning structure 9 in the pressure-bearing pipe body 1 and saves assembly time.

[0101] Example 6:

[0102] The structure of the annular cavity pressure differential flowmeter provided in Example 6 is basically the same as that in Example 1, except that, in Example 6, Figure 10 As shown, the throttling element 2 is an orifice throttling element.

[0103] Example 7:

[0104] The structure of the annular cavity pressure differential flowmeter provided in Example 7 is basically the same as that in Example 1, except that: in Example 7, at least one protrusion is provided on the bottom of the annular groove, and the protrusion is used to abut against one side of the positioning structure 9 toward the output side of the fluid medium of the pressure pipe body 1.

[0105] By providing a raised portion so that the raised portion abuts against one side of the annular member facing the output side of the fluid medium, the annular member (i.e., the positioning structure 9) can support the annular member when it and the throttling member 2 jointly bear the impact of the fluid medium in the flow direction, thereby reducing the force on the fixed connection between the annular member and the pressure-bearing pipe body 1 and protecting the fixed connection between the annular member and the pressure-bearing pipe body 1.

[0106] There are many ways to set the raised portion, including but not limited to the following solutions:

[0107] Option 1:

[0108] The number of the protrusion is one, the protrusion is annular, and extends along the circumference of the annular groove.

[0109] Option 2:

[0110] There are multiple protrusions, and the multiple protrusions are arranged at intervals along the circumference of the annular groove;

[0111] The number of raised portions is related to whether the arc-shaped parts 91 in the annular component (i.e., the positioning structure 9) are fixedly connected. If the arc-shaped parts 91 are not fixedly connected, the number of raised portions is related to the number of arc-shaped parts 91. At least one or more raised portions should be provided for each arc-shaped part 91 to abut against it. If the arc-shaped parts 91 are fixedly connected (e.g., the arc-shaped parts 91 are welded end to end), the number of raised portions is independent of the number of arc-shaped parts 91. Multiple raised portions can be arranged at circumferential intervals along the annular groove.

[0112] Specifically, in this embodiment 7, Figure 11 As shown, in order to ensure the positioning of the positioning structure 9 in the annular groove, a shoulder is provided at the bottom of the annular groove on the downstream side of the installation part of the positioning structure 9, or the annular groove is provided as a stepped groove (that is, the diameter of the annular groove on the downstream side of the positioning structure 9 is smaller than the diameter of the annular groove on the upstream side of the positioning structure 9).

[0113] Among them, due to the provision of the protrusion, the positioning structure 9 can also be fixed in the annular groove by a clamping strip;

[0114] Specifically, the annular cavity pressure-taking differential pressure flowmeter provided in this embodiment 7 also includes a plurality of clamping strips (not shown in the figure), each of which is arranged at the bottom of the first annular groove 11, and each of which is evenly distributed along the circumference of the first annular groove 11. One end of each clamping strip is against the side of the first annular groove 11 away from the positioning structure 9, and the other end is against the positioning structure 9.

[0115] Among them, the number of clamping strips is also related to whether the arc-shaped parts 91 in the annular component (that is, the positioning structure 9) are fixedly connected; if the arc-shaped parts 91 are not fixedly connected, the number of clamping strips is related to the number of arc-shaped parts 91, and at least one or more clamping strips should be provided to support each arc-shaped part 91. If the arc-shaped parts 91 are fixedly connected (such as: the arc-shaped parts 91 are welded end to end), the number of clamping strips is independent of the number of arc-shaped parts 91, and the clamping strips can be evenly distributed along the circumference of the first annular groove 11.

[0116] Example 8:

[0117] The structure of the annular cavity pressure differential flowmeter provided in Example 8 is basically the same as that of Example 1, except that: Figure 12 and Figure 13 As shown, the inner hole diameter of the positioning structure 9 is larger than the inner hole diameter of the inner sleeve 3; the inner sleeve 3 used to cover the first annular groove 11 is pressed against the throttling member 2 at one end toward the positioning structure 9 to make the female stop and the male stop fit tightly.

[0118] Its function is to enable the upstream inner sleeve 3 installed on the positioning structure 9 to press against the throttle member 2, and to achieve a tight fit between the male and female stoppers located on the throttle member 2 and the positioning structure 9. This method does not require welding the throttle member 2 to the positioning structure 9 and is suitable for applications where the internal space of the pressure pipe body 1 is not suitable for welding operations.

[0119] Correspondingly, the communication between the first annular cavity 4 upstream of the throttling member 2 and the corresponding inner cavity of the inner sleeve 3 cannot be achieved by leaving a gap, but should be achieved by grooving the end of the inner sleeve 3 close to the throttling member 2 or by opening a hole in the tube wall of the inner sleeve 3.

[0120] In this embodiment 8, Figure 14 and Figure 15 As shown, a method of slotting the end of the inner sleeve 3 close to the throttle member 2 for covering the first annular groove 11 is shown.

[0121] Specifically, a plurality of flow grooves 31 are provided on one end of the inner sleeve 3 facing the positioning structure 9 for covering the first annular groove 11. The flow grooves 31 are distributed at intervals along the circumference of the inner sleeve 3 to form a flow channel connecting the first annular cavity 4 and the inner hole of the inner sleeve 3 on the same side.

[0122] Example 9:

[0123] The structure of the annular cavity pressure differential flowmeter provided in Example 9 is substantially the same as that of Example 8, except that the arrangement of the flow passage on the inner sleeve 3 for shielding the first annular groove 11 is different;

[0124] In this embodiment 9, Figure 16 and Figure 17 As shown, a plurality of flow holes 32 are provided on the inner sleeve 3 for shielding the first annular groove 11 , and the flow holes 32 are spaced apart along the circumference of the inner sleeve 3 to form a flow channel connecting the first annular cavity 4 and the inner hole of the inner sleeve 3 on the same side.

[0125] The annular cavity pressure differential flowmeter provided by the present invention has at least the following technical effects or advantages:

[0126] 1. Since the pressure-bearing pipe body 1 is integrally formed without annular butt welds, there is no concern about insufficient load-bearing capacity of incomplete welds, stress concentration, and inability to perform volume non-destructive testing; compared with the flange connection structure, there is no concern about sealing surface leakage, and the geometric dimensions are compact, the processing technology is simple, and the manufacturing and installation costs are low; this solves the technical problems of existing annular cavity pressure differential flowmeters, which usually have complex processing technology and assembly procedures, large space occupation, long production cycle, high production cost, and high safety risks.

[0127] 2. Compared with the welding type of two-section clamping throttling piece, the lack of circumferential butt weld avoids the safety risks of pipe burst and leakage caused by insufficient weld cross-sectional area, inability to penetrate the weld root, prominent stress concentration in the weld joint, and inability to perform radiographic and ultrasonic testing on the weld joint.

[0128] 3. Compared with the flange clamping throttle form, it avoids the potential risk of leakage between the flange and the throttle sealing surface, has a compact structure, simple installation, and low manufacturing and installation costs.

[0129] 4. The opening on the inner sleeve 3 serves as a communication channel between the main fluid channel and the annular cavity, which can make the fluid in the annular cavity flow, avoid the accumulation of condensed liquid, and make the measurement data more reliable.

[0130] 5. The throttling part positioning structure and the pressure-bearing pipe body are manufactured separately to solve the difficulty of internal processing of the pressure-bearing pipe body of small-sized flow meters. The positioning structure adopts a petal form to solve the possibility of installation.

[0131] 6. By setting the male stop and the female stop, when the throttling member 2 is subjected to the impact of the flow direction of the fluid medium, the positioning structure 9 can form a support for the throttling member 2 through the cooperation and limitation of the male stop and the female stop, so as to reduce the force on the fixed connection between the throttling member 2 and the positioning structure 9, and form protection for the fixed connection between the throttling member 2 and the positioning structure 9.

[0132] 7. By providing a raised portion so that the raised portion abuts against one side of the annular member facing the output side of the fluid medium, when the annular member (i.e., the positioning structure 9) and the throttling member 2 jointly bear the impact of the flow direction of the fluid medium, the raised portion can support the annular member, thereby reducing the force on the fixed connection between the annular member and the pressure-bearing pipe body 1, and protecting the fixed connection between the annular member and the pressure-bearing pipe body 1.

[0133] 8. The upstream inner sleeve 3 mounted on the positioning structure 9 can be pressed against the throttle element 2, and the male and female stoppers on the throttle element 2 and the positioning structure 9 can be press-fitted. This method does not require welding the throttle element 2 to the positioning structure 9 and is suitable for applications where the internal space of the pressure pipe body 1 is not suitable for welding operations.

[0134] 9. By setting the positioning structure 9 as an annular protrusion integrally formed on the inner hole of the pressure-bearing pipe body 1, the positioning structure 9 can be processed together during the inner hole processing of the pressure-bearing pipe body 1. There is no need to set the positioning structure 9 as an additional assembly component, which reduces the processing steps of fixing the positioning structure 9 in the pressure-bearing pipe body 1 and saves assembly time.

[0135] The above are only specific application examples of the present invention and do not constitute any limitation to the protection scope of the present invention. Any technical solutions formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the present invention.

Claims

1. An annular cavity pressure differential flowmeter, characterized in that: The pressure-bearing pipe comprises a pressure-bearing pipe body, a throttle member, and two inner sleeves sleeved in the pressure-bearing pipe body. The pressure-bearing pipe body is used to convey a fluid medium. The pressure-bearing pipe body is integrally formed. A first annular groove, a positioning structure, and a second annular groove are sequentially formed on the inner hole of the pressure-bearing pipe body along the conveying direction of the fluid medium. The first annular groove and the second annular groove are both formed along the circumference of the pressure-bearing tube body. The positioning structure is annular and coaxial with the pressure-bearing tube body. The diameter of the inner hole of the positioning structure is no larger than the diameter of the inner hole of the pressure-bearing tube body. The throttle member is assembled in the positioning structure and fixedly connected to the positioning structure. The outer circumferential surface of the throttle member cooperates with the inner circumferential surface of the positioning structure. The two inner sleeves are both fixedly connected to the pressure-bearing pipe body, and the outer circumferential surfaces of the inner sleeves are matched with the inner holes of the pressure-bearing pipe body. The two inner sleeves are respectively arranged on both sides of the positioning structure, and are used to respectively cover the notches of the first annular groove and the second annular groove; so as to form a first annular cavity between the first annular groove and the inner sleeve on the same side, and a second annular cavity between the second annular groove and the inner sleeve on the same side; the inner sleeves are both provided with flow channels; the two flow channels are respectively used to connect the first annular cavity with the inner cavity of the inner sleeve on the same side, and to connect the second annular cavity with the inner cavity of the inner sleeve on the same side; The pressure-bearing pipe body is provided with two through holes, one of which is used to connect the first annular cavity with the upstream pressure measuring device, and the other through hole is used to connect the second annular cavity with the downstream pressure measuring device; One end of the inner sleeve away from the positioning structure is welded to the inner hole of the pressure-bearing pipe body; A male stop is provided on the side of the inner hole of the positioning structure close to the output side of the fluid medium of the pressure-bearing tube body, and a female stop is provided on the outer peripheral surface of the throttling member close to the output side of the fluid medium of the pressure-bearing tube body to match the male stop.

2. The annular cavity pressure differential flowmeter according to claim 1, characterized in that: The positioning structure is an annular protrusion integrally formed on the inner hole of the pressure-bearing pipe body.

3. The annular cavity pressure differential flowmeter according to claim 1, characterized in that: An annular groove is provided on the inner hole of the pressure-bearing pipe body along the circumferential direction. The positioning structure is an annular component fixedly connected to the annular groove. The outer circumferential surface of the annular component cooperates with the bottom of the annular groove. The annular component is used to separate the annular groove into the first annular groove and the second annular groove.

4. The annular cavity pressure differential flowmeter according to claim 3, characterized in that: At least one protrusion is provided on the bottom of the annular groove, and the protrusion is used to abut against a side of the annular component facing the output side of the fluid medium.

5. The annular cavity pressure differential flowmeter according to claim 4, characterized in that: The number of the protrusion is one, the protrusion is annular, and extends along the circumference of the annular groove.

6. The annular cavity pressure differential flowmeter according to claim 4, characterized in that: The annular cavity pressure differential flowmeter also includes a plurality of clamping strips, each of which is arranged at the bottom of the first annular groove, and each of which is evenly distributed along the circumference of the first annular groove. One end of each of the clamping strips is abutted against the side of the first annular groove away from the positioning structure, and the other end is abutted against the positioning structure.

7. The annular cavity pressure differential flowmeter according to any one of claims 3 to 6, characterized in that: The annular component includes at least three identical arc-shaped parts, and the arc-shaped parts are sequentially connected end to end along the circumference of the pressure-bearing pipe body to form a circular ring.

8. The annular cavity pressure differential flowmeter according to claim 1, characterized in that: The inner diameter of the positioning structure is larger than the inner diameter of the inner sleeve; the inner sleeve for covering the first annular groove is pressed against the throttling member at one end toward the positioning structure to ensure a tight fit between the female stop and the male stop.

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