Main water supply Venturi tube

Abstract

The utility model provides a main water supply Venturi tube, which belongs to the technical field of pipelines, and comprises an upstream straight tube section, an integrated forge piece tube body, at least one expansion section and a downstream straight tube section, the integrated forge piece tube body is provided with a contraction section and a throat part along the axial direction, the downstream straight tube section is coaxially sleeved outside the expansion section, and the expansion section is sleeved outside the downstream straight tube section. One end of the integrated forge piece pipe body is welded with the upstream straight pipe section, and the other end of the integrated forge piece pipe body is respectively welded with the expansion section and the downstream straight pipe section; according to the utility model, the contraction section and the throat part are designed into an integrated forge piece structure and then are respectively welded with the upstream straight pipe section, the downstream straight pipe section and the expansion section, so that the integral structure of the venturi tube is simplified, and meanwhile, the venturi tube has higher integral structural strength, so that the use safety of the venturi tube is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pipelines, in particular to a main water supply Venturi tube. Background Art

[0002] The Venturi tube is a differential pressure throttling device that meets the requirements of GB / T 2624-2006 standard. The main feedwater Venturi tube is installed on the main feedwater pipeline of the nuclear power plant. The fluid flows through the Venturi tube, and the flow beam forms a local contraction at the throat of the Venturi tube, thereby increasing the flow velocity and reducing the static pressure. Thus, a static pressure difference is generated between the upstream side and the throat of the Venturi tube. According to the differential pressure and fluid characteristics, the fluid flow in the pipeline can be measured. This measurement method is based on the law of conservation of energy and the flow continuity equation.

[0003] The inventors have found that most of the existing main water supply Venturi tube structures adopt a sleeve type (outer tube + Venturi inner tube) structure. The Venturi inner tube is made of steel plate rolled and welded, and the throat is made of a stainless steel hose to draw pressure. During long-term use, it is found that the total length of the inner tube of the Venturi tube with this structure is usually about 2 meters, the upstream end is welded and fixed to the outer sleeve, and the downstream end is freely in contact with the outer sleeve. The middle is suspended without effective support, and the structural strength is low. Long-term use under high flow conditions will cause the inner tube to deform due to vibration. When the residual deformation exceeds the standard shape and size of the Venturi tube, measurement deviation will occur, and there will be safety hazards. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings and deficiencies of the prior art and to provide a main water supply venturi tube.

[0005] The technical solution adopted by the utility model is as follows: a main water supply Venturi tube, including an upstream straight pipe section, an integrated forged pipe body, at least one expansion section and a downstream straight pipe section, the integrated forged pipe body is axially provided with a contraction section and a throat, the downstream straight pipe section is coaxially sleeved outside the expansion section, and a cavity is formed between the two, one end of the integrated forged pipe body is welded to the upstream straight pipe section, and the other end is respectively welded to the expansion section and the downstream straight pipe section.

[0006] Preferably, the length of the contraction section is shorter than the length of the expansion section.

[0007] Preferably, there are at least two expansion sections, each of which is welded into one body, and one end of which is welded to the integrated forging pipe body, and the other end is in free contact with the downstream straight pipe section. A reinforcement ring is arranged between each expansion section and the downstream straight pipe section, and the inner ring of the reinforcement ring is welded to the outer wall of the corresponding expansion section.

[0008] Preferably, a plurality of through holes communicating with the cavity are circumferentially arranged on the expansion section, and each of the through holes is located on the same cross section.

[0009] Preferably, a build-up welding groove is provided at the connection position between the contraction section and the throat, and hard alloy is build-up welded in the build-up welding groove.

[0010] Preferably, a first pressure-equalizing ring is provided on the outer wall of the integrated forging tube body corresponding to the throat, and the first pressure-equalizing ring is provided with a first exhaust port, a first sewage outlet and at least one first pressure port.

[0011] Preferably, a visual device is provided on the integrated forging tube body at a position corresponding to the contraction section, and the visual device includes a visible through hole connected to the inner cavity of the contraction section, a plug core, a fixed flange and a flange cover, the fixed flange is welded to the integrated forging tube body, the plug core is detachably arranged relative to the visible through hole, one end of the flange cover is rotatably arranged on the fixed flange through a positioning pin, and the other end is connected to the fixed flange through bolts.

[0012] Preferably, a second pressure-equalizing ring is provided on the upstream straight pipe section, and a second air exhaust port, a second sewage outlet, and a second pressure-taking port corresponding to the first pressure-taking port are provided on the second pressure-equalizing ring.

[0013] Preferably, a third pressure-equalizing ring is provided on the downstream straight pipe section, a third exhaust port and a third sewage outlet are provided on the third pressure-equalizing ring, and both the third exhaust port and the third sewage outlet are communicated with the cavity.

[0014] Preferably, each exhaust port is located at the top of the corresponding pressure equalizing ring, and each sewage port is located at the bottom of the corresponding pressure equalizing ring. There are two first pressure ports and two second pressure ports, and they are symmetrically arranged on the left and right sides of the connecting line between the corresponding exhaust port and the sewage port.

[0015] The beneficial effects of the utility model are as follows: in the utility model, the contraction section and the throat are designed as an integrated forging structure, which is then welded to the upstream and downstream straight pipe sections and the expansion section respectively, which simplifies the overall structure of the Venturi tube and has a higher overall structural strength, thereby improving its safety in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model 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 utility model. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the utility model.

[0017] Figure 1 It is a schematic diagram of the utility model;

[0018] Figure 2 for Figure 1Sectional view at point A;

[0019] Figure 3 for Figure 1 Sectional view at B in the middle;

[0020] Figure 4 for Figure 1 Enlarged view of point C in the middle;

[0021] Figure 5 It is a schematic diagram of the visual device in the utility model;

[0022] Figure 6 for Figure 1 The enlarged view of point D in the middle;

[0023] Figure 7 It is a schematic diagram of the reinforcing ring in the utility model. DETAILED DESCRIPTION

[0024] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0025] In the description of the present application, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise specified, "plurality" means two or more.

[0026] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] In the description of this application, it should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0028] Embodiment 1:

[0029] like Figures 1 to 7 As shown, a main water supply venturi tube includes an upstream straight pipe section 1, an integrated forged pipe body 2, at least one expansion section 3 and a downstream straight pipe section 4, wherein the integrated forged pipe body 2 is axially provided with a contraction section 21 and a throat 22, and the downstream straight pipe section 4 is coaxially sleeved outside the expansion section 3, and a cavity 5 is formed between the two, and one end of the integrated forged pipe body 2 is welded to the upstream straight pipe section 1, and the other end is respectively welded to the expansion section 3 and the downstream straight pipe section 4. Specifically, as shown in FIG. Figure 1 As shown, a first welding convex ring and a second welding convex ring are coaxially arranged at one end of the integrated forging pipe body 2 close to the downstream straight pipe section 4, wherein the downstream straight pipe section 4 is welded to the first welding convex ring, and the expansion section 3 is welded to the second welding convex ring.

[0030] Compared with the traditional Venturi tube, which adopts the structure of an outer sleeve with an inner tube of the Venturi tube, it is easy for the inner tube to deform due to vibration when used under long-term high-flow conditions. When the residual deformation exceeds the standard shape and size of the Venturi tube, measurement deviation will occur, and there will be safety hazards. Therefore, through the above-mentioned setting, the contraction section 21 and the throat 22 are designed as an integrated forging structure, and then welded to the upstream and downstream straight pipe sections and the expansion section 3 respectively, which simplifies the overall structure of the Venturi tube and has a higher overall structural strength, thereby improving its safety in use.

[0031] Secondly, since the Venturi tube flow measurement device generally has a pressure tapping port on the upstream straight pipe section 1 and a corresponding pressure tapping port on the throat, the pressure tapping port on the upstream straight pipe section 1 is generally 1 / 2D away from the maximum cross-section of the contraction section, where D is the inner diameter of the upstream straight pipe section 1. If the contraction section is connected to the outer casing by welding, the pressure tapping distance 1 / 2D will be difficult to guarantee, thereby affecting the measurement accuracy.

[0032] Furthermore, the length of the contraction section 21 is smaller than the length of the expansion section 3 . In this embodiment, the length of the expansion section 3 is at least twice the length of the contraction section 21 .

[0033] Through this arrangement, the contraction section 21 is prevented from being too long, and the overall length of the integrated forging tube body 2 is reduced, thereby reducing its weight and manufacturing cost, while reducing pressure loss; wherein, the longer expansion section 3 allows the fluid to have sufficient length to restore pressure and reduce turbulence and flow separation caused by changes in flow velocity.

[0034] Furthermore, there are at least two expansion sections 3, each of which is welded into one body, and one end of which is welded to the integrated forging pipe body 2, and the other end is in free contact with the downstream straight pipe section 4. A reinforcement ring 6 is provided between each expansion section 3 and the downstream straight pipe section 4. The inner ring of the reinforcement ring 6 is welded to the outer wall of the corresponding expansion section 3, and is processed and inserted into the downstream straight pipe section 4 in cooperation with the downstream straight pipe section 4, effectively enhancing the structural strength of the expansion section 3 and the downstream straight pipe section 4. In this embodiment, the wall thickness of the expansion section 3 is increased to 12 mm.

[0035] Through the above arrangement, four supporting and fixing points can be formed for the internal flow channel composed of the contraction section 21, the throat 22 and the expansion section 3, namely the welding point with the throat 22, the two reinforcement rings 6 and the free contact point between the end of the expansion section 3 and the downstream straight pipe section 4, thereby ensuring that the Venturi tube has a higher overall structural strength.

[0036] Furthermore, a plurality of through holes 7 connected to the cavity 5 are circumferentially arranged on the expansion section 3 , and each of the through holes 7 is located on the same cross section. In this embodiment, four through holes 7 are circumferentially arranged on the expansion section 3 and are located between the two reinforcement rings 6 .

[0037] like Figure 7 As shown, the reinforcement ring 6 is evenly provided with four arc-shaped recesses 61 along the circumferential direction. During assembly, the arc-shaped recesses 61 are aligned with the bottom of the downstream straight pipe section 4 .

[0038] Through the above arrangement, the pressure and flow pulsation generated when the fluid passes through the expansion section 3 can be reduced.

[0039] Furthermore, when the fluid flows through the throat, the inner tube gradually contracts, and the flow velocity and impact force are the largest at the transition between the contraction section 21 and the throat 22. This is also the most susceptible to wear in the entire Venturi tube. After a period of use, the Venturi tube will cause severe wear and tear at this point and may even be worn through, posing a serious safety hazard.

[0040] Therefore, a build-up welding groove 8 is provided at the connection position between the contraction section 21 and the throat portion 22 , and hard alloy is build-up welded in the build-up welding groove 8 .

[0041] In this embodiment, if Figure 4As shown, the length L1 of the surfacing groove 8 located in the contraction section 21 is not less than 50mm, the length L2 of the surfacing groove 8 located in the throat 22 is not less than 30mm, the depth H of the surfacing groove 8 is not less than 4mm, and the surfacing depth is generally required to be not less than 4mm after fine processing, and the hardness of the surfacing cemented carbide is not less than 35HRC. Among them, due to the large difference between the hardness of the surfacing layer and the hardness of the parent material, in order to ensure the quality of the surfacing, the parent material forging needs to be subjected to stress relief heat treatment during production, and stress relief heat treatment is also required after surfacing.

[0042] Through the above arrangement, the hardness and wear resistance of the surfacing carbide layer are greatly increased compared with the base material, which avoids the possibility of severe wear or even wear-through of the connection between the contraction section 21 and the throat 22, and greatly increases the service life of the Venturi tube.

[0043] Furthermore, since the design life of the main water supply venturi tube is 40 or 60 years, it will work under high temperature, high pressure, high flow rate and large flow rate for a long time. As the service life increases, the venturi tube will wear out. At the same time, the carbon steel venturi tube is prone to produce oxide film during commissioning and overhaul. When the thickness of the oxide film in key parts such as the throat reaches a certain amount, it will have a great impact on the measurement accuracy of the venturi tube.

[0044] Therefore, a visual device 13 is provided on the integrated forging tube body 2 at a position corresponding to the contraction section 21, and the visual device 13 includes a visible through hole 131 connected to the inner cavity of the contraction section 21, a plug core 132, a fixed flange 133 and a flange cover 134, the fixed flange 133 is welded to the integrated forging tube body 2, and a channel coaxial with and connected to the visible through hole 131 is provided on the fixed flange 133, the plug core 132 is detachably arranged relative to the visible through hole 131, for example, the plug core 132 is inserted into the channel and the visible through hole 131, one end of the flange cover 134 is rotatably arranged on the fixed flange 133 by a positioning pin 135, and the other end is connected to the fixed flange 133 by a bolt 136, and a plurality of bolts 136 can be arranged circumferentially.

[0045] Through the above arrangement, the plug core 132 can be disassembled and withdrawn when necessary, and the wear condition of the inside of the venturi tube, especially the transition between the contraction section 21 and the throat 22, and the degree of oxide film accumulation can be checked with the help of optical fiber, probe and other equipment. When the measurement deviation of the venturi tube occurs or the deviation exceeds the working criteria, the inside of the venturi tube can be inspected. If it is confirmed that it is caused by the wear of the venturi tube, the venturi tube can be repaired or even replaced; if it is caused by the accumulation of oxide film, it can be cleaned with commercial cleaning agents or fine friction materials that are harmless to the equipment.

[0046] Secondly, the positioning pins prevent displacement when reinstalling after disassembly, so as not to affect the measurement.

[0047] Furthermore, since the pressure-inducing and exhaust devices on the conventional Venturi tube are connected by stainless steel hoses, internal leakage may occur during long-term use, thus affecting the measurement accuracy.

[0048] Therefore, a first pressure-equalizing ring 9 is provided on the outer wall of the throat 22 of the integrated forging tube body 2, and a first exhaust port 10, a first sewage outlet 11 and at least one first pressure port 12 are provided on the first pressure-equalizing ring 9. In the present embodiment, two first pressure ports 12 are provided, and the first sewage outlet 11 is symmetrically arranged on the left and right.

[0049] Through the above arrangement, a rigid pressure-taking and exhaust equalizing ring structure is adopted, which is safer and more reliable, and can avoid hidden dangers of internal leakage and service life problems caused by deformation of the pressure-leading hose, thereby extending the service life of the Venturi tube and simplifying the product structure.

[0050] At the same time, due to pipeline maintenance, possible debris in the medium, rust on the equipment body, etc., after a certain period of use, debris will accumulate inside the pressure equalizing ring of the Venturi tube. If it is not cleaned for a long time, it may interfere with or even block the pressure pipe, making on-site cleaning more cumbersome.

[0051] Therefore, a second pressure equalizing ring 14 is provided on the upstream straight pipe section 1 , and a second exhaust port 15 , a second sewage outlet 16 , and a second pressure taking port 17 corresponding to the first pressure taking port 12 are provided on the second pressure equalizing ring 14 .

[0052] The downstream straight pipe section 4 is provided with a third pressure equalizing ring 18 , and the third pressure equalizing ring 18 is provided with a third exhaust port 19 and a third sewage outlet 20 , and both the third exhaust port 19 and the third sewage outlet 20 are communicated with the cavity 5 .

[0053] Each exhaust port is located at the top of the corresponding pressure equalizing ring, and each sewage port is located at the bottom of the corresponding pressure equalizing ring. There are two first pressure ports 12 and two second pressure ports 17, and they are respectively arranged symmetrically with respect to the connecting line of the corresponding exhaust port and the sewage port. In this embodiment, one of the two first pressure ports 12 and the two second pressure ports 17 is arranged 65° to the left relative to the lowest point of the corresponding pipeline, and the other is arranged 65° to the right relative to the lowest point of the corresponding pipeline.

[0054] Through the above arrangement, a sewage outlet is provided at the bottom of each pressure equalizing ring of the Venturi tube, and an exhaust outlet is provided at the top, so as to facilitate regular cleaning of debris. When cleaning, the valve at the pressure taking port is closed, and the valves at the exhaust port and the sewage outlet are opened, and high-pressure water or high-pressure air is flushed in from the exhaust port to discharge the debris from the sewage outlet.

[0055] In addition, the inner surface of the Venturi tube is finely processed as a whole to ensure the processing accuracy and surface roughness of each section of the Venturi tube, especially to ensure its overall coaxiality, so that the measurement accuracy of the Venturi tube is greatly improved.

[0056] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.

Claims

1. A main water supply venturi tube, characterized in that: The invention comprises an upstream straight pipe section (1), an integrated forged pipe body (2), at least one expansion section (3) and a downstream straight pipe section (4); the integrated forged pipe body (2) is provided with a contraction section (21) and a throat section (22) along the axial direction; the downstream straight pipe section (4) is coaxially sleeved outside the expansion section (3), and a cavity (5) is formed between the two; one end of the integrated forged pipe body (2) is welded to the upstream straight pipe section (1), and the other end is respectively welded to the expansion section (3) and the downstream straight pipe section (4).

2. A main water supply venturi tube according to claim 1, characterized in that: The length of the contraction section (21) is smaller than the length of the expansion section (3).

3. A main water supply venturi tube according to claim 1, characterized in that: There are at least two expansion sections (3), each of which is welded into one piece, and one end of which is welded to the integrated forged pipe body (2), and the other end of which is in free contact with the downstream straight pipe section (4). A reinforcement ring (6) is provided between each expansion section (3) and the downstream straight pipe section (4), and the inner ring of the reinforcement ring (6) is welded to the outer wall of the corresponding expansion section (3).

4. A main water supply venturi tube according to claim 1, characterized in that: The expansion section (3) is circumferentially provided with a plurality of through holes (7) connected to the cavity (5), and each of the through holes (7) is located on the same cross section.

5. A main water supply venturi tube according to claim 1, characterized in that: A build-up welding groove (8) is provided at the connection position between the contraction section (21) and the throat (22), and hard alloy is build-up welded in the build-up welding groove (8).

6. A main water supply venturi tube according to claim 1, characterized in that: A first pressure equalizing ring (9) is provided on the outer wall of the integrated forging tube body (2) corresponding to the throat (22), and the first pressure equalizing ring (9) is provided with a first exhaust port (10), a first sewage outlet (11) and at least one first pressure taking port (12).

7. A main water supply venturi tube according to claim 1, characterized in that: A visual device (13) is provided on the integrated forged pipe body (2) at a position corresponding to the contraction section (21), the visual device (13) comprising a visual through hole (131) communicating with the inner cavity of the contraction section (21), a plug core (132), a fixed flange (133) and a flange cover (134), the fixed flange (133) being welded to the integrated forged pipe body (2), the plug core (132) being detachably arranged relative to the visual through hole (131), one end of the flange cover (134) being rotatably arranged on the fixed flange (133) by means of a positioning pin, and the other end being connected to the fixed flange (133) by means of a bolt.

8. A main water supply venturi tube according to claim 6, characterized in that: The upstream straight pipe section (1) is provided with a second pressure equalizing ring (14), and the second pressure equalizing ring (14) is provided with a second exhaust port (15), a second sewage outlet (16), and a second pressure taking port (17) arranged corresponding to the first pressure taking port (12).

9. A main water supply venturi tube according to claim 8, characterized in that: The downstream straight pipe section (4) is provided with a third pressure equalizing ring (18), and the third pressure equalizing ring (18) is provided with a third exhaust port (19) and a third sewage outlet (20), and the third exhaust port (19) and the third sewage outlet (20) are both connected to the cavity (5).

10. A main water supply venturi tube according to claim 9, characterized in that: Each exhaust port is located at the top of the corresponding pressure equalizing ring, and each sewage outlet is located at the bottom of the corresponding pressure equalizing ring. There are two first pressure ports (12) and two second pressure ports (17), and they are symmetrically arranged on the left and right sides of the connecting line between the corresponding exhaust ports and sewage outlets.

Images