Slip-type sub-rigid structure expansion joint

Abstract

The application discloses a kind of live knot type sub-rigid structure expansion joint, for being connected between relatively spaced inlet pressure pipe and outlet pressure pipe, live knot type sub-rigid structure expansion joint includes: relatively spaced inlet wave shell disc and outlet wave shell disc between inlet pressure pipe and outlet pressure pipe, wave shell body being disposed between inlet wave shell disc and outlet wave shell disc along the axis direction, and rigid ring being sleeved on wave shell body outside and being connected with inlet wave shell disc, pressure pipe and outlet wave shell disc, pressure pipe respectively at both ends.Slot is equipped with wave core body outside wave shell body.Inlet wave shell disc is detachably fixed with inlet pressure pipe by first fastener, and outlet wave shell disc is detachably fixed with outlet pressure pipe by second fastener.Both ends of wave shell body are welded and fixed with inlet wave shell disc and outlet wave shell disc respectively, and constitute a kind of live knot type sub-rigid structure expansion joint, so that expansion element, sealing element, live knot element are all in the protection of rigid ring elastic strain field, with long service life, maintenance-free, safe and reliable operation.

Description

Technical Field

[0001] The invention relates to the field of expansion joint devices for connecting penstocks of hydropower stations, and in particular to a slipknot-type expansion joint with a sub-rigid structure.

[0002] The pressure steel pipes used in hydropower stations will expand and contract along the pipe axis when the temperature changes, generating large and destructive temperature stresses in the pipe wall. In order to avoid this phenomenon, expansion joints are set on the pressure steel pipes so that the steel pipes can expand and contract freely along the axial direction or have slight angular displacements at the same time when the temperature changes. Background Art

[0003] The traditional expansion joint is a sliding sleeve type, and its structure is as follows Figure 1 As shown in the figure, a circular sleeve is welded to one side of two adjacent pipe sections, into which the other pipe section extends. The annular gap between the sleeve and the steel pipe is filled with sealing filler, which is then compressed by a bolted compression ring to achieve the purpose of water sealing. Unstoppable leakage and frequent maintenance are the characteristics of sleeve expansion joints, especially large-diameter, high-water-pressure expansion joints.

[0004] An existing bellows shell sealed expansion joint device is as follows Figure 2 As shown, it includes an inlet pressure short tube 11, an outlet pressure short tube 12, an inlet wave core ring 13, an outlet wave core ring 14, a wave shell 50, a rigid ring 60 and a wave core body 70, wherein the inlet wave core ring 13 is welded to the inlet pressure short tube 11, the outlet wave core ring 14 is welded to the outlet pressure short tube 12, the two ends of the wave shell 50 are respectively connected to the inlet wave core ring 13 and the outlet wave core ring 14 by welding, the two ends of the rigid ring 60 are respectively sealed and connected to the outer wall surface of the inlet pressure short tube 11 and the outlet pressure short tube 12 and are provided with at least one free end, and the wave core body 70 is divided into blocks and installed between the inward wave cavity of the wave shell 50 and the rigid ring 60.

[0005] This expansion joint features a semi-rigid structure with flexible expansion and contraction, equivalent strength to that of a pressure steel pipe, and is completely sealed and watertight. The fully enclosed welded connection between the corrugated shell and the pressure stub makes disassembly and replacement of the corrugated shell difficult. However, the replacement of the corrugated shell, a vulnerable component, is essential. Summary of the Invention

[0006] The present invention provides a slipknot-type sub-rigid structure expansion joint to solve the problem of replacing the corrugated shell body, a vulnerable part, with a new one in the existing expansion joint device, and makes some related improvements.

[0007] The technical solution adopted in the present invention is as follows:

[0008] A slipknot-type sub-rigid structure expansion joint is used in a hydropower station and is used to connect between an inlet pressure pipe and an outlet pressure pipe that are relatively spaced apart. The slipknot-type sub-rigid structure expansion joint includes: an inlet corrugated shell disk and an outlet corrugated shell disk that are relatively spaced apart between the inlet pressure pipe and the outlet pressure pipe, a corrugated shell body that is axially arranged between the inlet corrugated shell disk and the outlet corrugated shell disk, a rigid ring that is sleeved outside the corrugated shell body and the corrugated shell disk and has its two ends respectively sleeved and connected to the inlet pressure pipe and the outlet pressure pipe, and a corrugated core body filled between the rigid ring and the corrugated shell body; the inlet corrugated shell disk is detachably fixed to the inlet pressure pipe by a first fastener, and the outlet corrugated shell disk is detachably fixed to the outlet pressure pipe by a second fastener; and the two ends of the corrugated shell body are respectively welded and fixed to the inlet corrugated shell disk and the outlet corrugated shell disk.

[0009] Furthermore, the inlet corrugated shell disk and the outlet corrugated shell disk are both annular; the inner diameter of the inlet corrugated shell disk is not less than the inner diameter of the inlet pressure pipe, and the outer diameter of the inlet corrugated shell disk is not greater than the outer diameter of the inlet pressure pipe; the inner diameter of the outlet corrugated shell disk is equal to the inner diameter of the outlet pressure pipe, and the outer diameter of the outlet corrugated shell disk is not greater than the outer diameter of the outlet pressure pipe.

[0010] Furthermore, the material of both the inlet corrugated shell disc and the outlet corrugated shell disc is the same as the material of the corrugated shell body.

[0011] Furthermore, the number of the first fasteners and the second fasteners are both multiple; the multiple first fasteners are evenly spaced along the circumference of the inlet corrugated shell disk, and the connecting end of each first fastener is perpendicularly passed through the inlet corrugated shell disk from the outer end surface of the inlet corrugated shell disk and then extends into the inlet pressure pipe; the multiple second fasteners are evenly spaced along the circumference of the outlet corrugated shell disk, and the connecting end of each second fastener is perpendicularly passed through the outlet corrugated shell disk from the outer end surface of the outlet corrugated shell disk and then extends into the outlet pressure pipe.

[0012] Furthermore, the first fastener and the second fastener are both flange screws, and the first fastener is located below the connection position between the corrugated shell and the inlet corrugated shell disk, and the second fastener is located below the connection position between the corrugated shell and the outlet corrugated shell disk.

[0013] Furthermore, the slipknot-type sub-rigid structure expansion joint also includes a first seal and a second seal; the first seal is arranged between the inlet corrugated shell disc and the inlet pressure pipe to seal the gap between the two; the second seal is arranged between the outlet corrugated shell disc and the outlet pressure pipe to seal the gap between the two.

[0014] Furthermore, the first seal and the second seal are both sealing rings, and the number of sealing rings is one; an inward-concave annular groove is provided on the water outlet side end face of the inlet pressure pipe, and a sealing ring is provided in the annular groove; an inward-concave annular groove is provided on the water inlet side end face of the outlet pressure pipe, and a sealing ring is provided in the annular groove.

[0015] Furthermore, the slipknot-type sub-rigid structure expansion joint also includes an anti-wear ring for reducing the wear of the medium on the corrugated shell; the anti-wear ring is located in the inlet corrugated shell disk, and the water inlet end of the anti-wear ring is detachably fixed to the inlet corrugated shell disk by a third fastener, and the water outlet end of the anti-wear ring extends toward the outlet corrugated shell disk.

[0016] Furthermore, the third fastener is a connecting screw, and there are multiple connecting screws, which are evenly spaced along the circumference of the anti-wear ring; the connecting end of each connecting screw passes vertically through the inner ring surface of the anti-wear ring and then extends into the inlet corrugated shell disk.

[0017] Furthermore, the slip-knot type sub-rigid structure expansion joint also includes an inlet end pressure plate, an outlet end pressure plate, a third seal and a fourth seal; the rigid ring is spaced apart and sleeved outside the wave shell, and the two ends of the rigid ring extend to the spaced apart sleeves outside the inlet pressure pipe and the outlet pressure pipe respectively; the inlet end pressure plate is spaced apart and sleeved outside the inlet pressure pipe, and is fixed to the first end face of the rigid ring, and the outlet end pressure plate is spaced apart and sleeved outside the outlet pressure pipe, and is fixed to the second end face of the rigid ring; the third seal is sealedly sleeved on the outer circle of the inlet pressure pipe, and is located between the inlet end pressure plate and the rigid ring, so as to seal the gap between the inlet pressure pipe and the rigid ring; the fourth seal is sealedly sleeved on the outer circle of the outlet pressure pipe, and is located between the outlet end pressure plate and the rigid ring, so as to seal the gap between the outlet pressure pipe and the rigid ring.

[0018] The present invention has the following beneficial effects:

[0019] In the slipknot-type sub-rigid body structure expansion joint structure of the present invention, the two ends of the corrugated shell are respectively welded and fixed to the inlet corrugated shell plate and the outlet corrugated shell plate to form a corrugated shell assembly, and the inlet corrugated shell plate is detachably fixed to the inlet pressure pipe by a first fastener, and the outlet corrugated shell plate is detachably fixed to the outlet pressure pipe by a second fastener, thereby making it a detachable slipknot structure of the corrugated shell assembly, meeting the normal replacement needs of wearing parts.

[0020] like Figure 1 As shown in the figure, the slipknot sub-rigid structure expansion joint consists of a corrugated shell assembly consisting of a corrugated shell and a corrugated shell disk. Under the action of the water pressure of the pressure steel pipe, the corrugated shell assembly generates elastic strain and transmits force to the rigid ring and the pressure pipe through the corrugated core to form a sub-rigid structure, thereby reliably ensuring the structural strength of the corrugated shell and the corrugated shell disk.

[0021] The slipknot structure of this slipknot expansion joint can be welded with the same steel for the corrugated shell and the corrugated shell plate, which greatly improves the corrosion resistance and service life of the structure compared with the dissimilar steel welds of the original structure.

[0022] The slipknot sub-rigid expansion joint of the present invention provides the feasibility of normal operation of the wearing part wave shell by replacing the old one with a new one due to the structure of the slipknot corrugated shell assembly, and provides functional guarantee, process guarantee, quality guarantee and life guarantee of the sub-rigid structure expansion joint.

[0023] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 It is a traditional sliding sleeve expansion joint;

[0026] Figure 2 The utility model is an expansion joint device for sealing an existing corrugated shell.

[0027] Figure 3 It is a schematic diagram of the main structure of a slipknot-type sub-rigid structure expansion joint according to a preferred embodiment of the present invention.

[0028] Legend

[0029] 11. Inlet pressure short pipe; 12. Outlet pressure short pipe; 13. Inlet corrugated core ring; 14. Outlet corrugated core ring; 20. Inlet pressure pipe; 30. Outlet pressure pipe; 40. Inlet corrugated shell disk; 50. Corrugated shell body; 60. Rigid ring; 70. Corrugated core body; 80. Outlet corrugated shell disk; 90. First fastener; 110. Second fastener; 120. First seal; 130. Second seal; 140. Anti-wear ring; 150. Third fastener; 160. Inlet end pressure plate; 170. Outlet end pressure plate; 180. Third seal; 190. Fourth seal. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0031] Reference Figure 3A preferred embodiment of the present invention provides a slipknot-type, sub-rigid expansion joint for use in hydropower stations, connected between an inlet pressure pipe 20 and an outlet pressure pipe 30 spaced relatively apart. The slipknot-type, sub-rigid expansion joint comprises: an inlet corrugated shell disc 40 and an outlet corrugated shell disc 80 spaced relatively apart between the inlet pressure pipe 20 and the outlet pressure pipe 30; a corrugated shell 50 axially disposed between the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80; a rigid ring 60 sleeved over the corrugated shell 50 and the corrugated shell disc 40, with both ends respectively connected to the inlet pressure pipe 20 and the outlet pressure pipe 30; and a corrugated core 70 filling the space between the rigid ring 60 and the corrugated shell 50. The inlet corrugated shell disc 40 is removably secured to the inlet pressure pipe 20 by a first fastener 90, and the outlet corrugated shell disc 80 is removably secured to the outlet pressure pipe 30 by a second fastener 110. The ends of the corrugated shell 50 are respectively welded to the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80.

[0032] In the slipknot sub-rigid body structure expansion joint structure of the present invention, the two ends of the corrugated shell 50 are respectively welded and fixed to the inlet corrugated shell plate 40 and the outlet corrugated shell plate 80 to form a corrugated shell assembly, and the inlet corrugated shell plate 40 is detachably fixed to the inlet pressure pipe 20 by the first fastener 90, and the outlet corrugated shell plate 80 is detachably fixed to the outlet pressure pipe 30 by the second fastener 110, thereby forming a detachable slipknot structure of the corrugated shell assembly, meeting the normal replacement needs of wearing parts. Figure 1 As shown, the slipknot-type sub-rigid structure expansion joint is composed of a corrugated shell assembly consisting of a corrugated shell 50 and a corrugated shell disk. Under the action of the water pressure of the pressure steel pipe, the corrugated shell assembly generates elastic strain and transmits force to the rigid ring 60 and the pressure pipe through the corrugated core 70 to form a sub-rigid structure, thereby reliably ensuring the structural strength of the corrugated shell 50 and the corrugated shell disk. The slipknot structure of this slipknot-type expansion joint can be welded with the same steel of the corrugated shell 50 and the corrugated shell disk, which greatly improves the corrosion resistance and service life of the structure compared to the dissimilar steel welds of the original structure. The slipknot-type sub-rigid body expansion joint of the present invention, due to the structure of the slipknot-type corrugated shell assembly, provides the feasibility of normal operation of the corrugated shell replacement of the wearing part, and provides functional guarantee, process guarantee, quality guarantee and service life guarantee for the sub-rigid body structure expansion joint.

[0033] Compared with the existing expansion joint structure in which the connecting flange is connected to the outside of the pressure steel pipe, and since the outer diameter of the pressure steel pipe is larger, generally greater than 8.2m, which leads to a larger inner diameter of the connecting flange, the overall size of the connecting flange is too large, and the processing and manufacturing are difficult. In addition, the larger inner diameter of the connecting flange leads to a reduction in its overall rigidity, which in turn affects the safety and reliability of the work. In the slipknot-type sub-rigid body structure expansion joint structure of the present invention, the two ends of the corrugated shell 50 are respectively welded and fixed to the inlet corrugated shell plate 40 and the outlet corrugated shell plate 80, and the inlet corrugated shell plate 40 is detachably fixed to the inlet pressure pipe 20 by a first fastener 90, and the outlet corrugated shell plate 80 is detachably fixed to the outlet pressure pipe 30 by a second fastener 110, thereby The inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 become part of the sub-rigid structure, so that the slipknot sub-rigid structure expansion joint of the present invention can be disassembled and repaired as a whole. The disassembly and repair operation is simple, and only the first fastener 90 and the second fastener 110 need to be removed. The maintenance operation is simple and easy to repair and modify. On the other hand, the inlet corrugated shell disc 40 and the inlet pressure pipe 20 are detachably fixed by the first fastener 90, and the outlet corrugated shell disc 80 and the outlet pressure pipe 30 are detachably fixed by the second fastener 110. Compared with the welding fixation between the two, the connection strength between the two is high, the connection stability is good, and the corrosion resistance is strong, thereby improving the service life of the device and making it safe and reliable during operation. ; The flange is set inside the rigid ring 60, breaking the existing conventional connection flange being set outside the pressure steel pipe. When the corrugated shell 50 is subjected to complex forces, its axial force is transmitted to the inlet pressure pipe 20 and the outlet pressure pipe 30 respectively through the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 at both ends. The inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 play a simple sealing connection and axial force transmission role. Compared with the external connection flange, the force it is subjected to is smaller, and when the flange is set inside the rigid ring 60, the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 are smaller in size. Therefore, when the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 are set inside, not only is the processing simpler, but the structure is also strong. The strength and working stability are higher, and the thickness setting can be increased, which can also improve the corrosion resistance of the connection, and ultimately extend the service life of the entire expansion joint structure, enhance the quality and working reliability. In addition, the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 are located in the rigid ring 60, and are sealed and protected by the rigid ring 60 to prevent the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 themselves, and the connection with the inlet pressure pipe 20 and the outlet pressure pipe 30 from being damaged due to external factors; the slipknot type sub-rigid structure expansion joint of the present invention provides material guarantee, process guarantee, quality guarantee and life guarantee for the use of the corrugated shell assembly. It is suitable for use in new equipment, and is more suitable for the transformation of old equipment, and is convenient for providing assembly spare parts.

[0034] Optionally, the slipknot-type sub-rigid structure expansion joint of the present invention can be used to connect the water diversion steel pipe sections of a hydropower station and the water diversion steel pipe sections with the inlet end of the water wheel volute, and can be used to connect the inlet end of the expansion joint with different pipe diameters and different liquid media such as oil and water with the pressure steel pipe of a hydropower station.

[0035] Optionally, the corrugated shell 50 may be a bellows, and the number of corrugated sections of the corrugated shell 50 may be one or more, depending on actual usage. In this optional solution, the ends of the corrugated shell 50 are welded to the side walls of the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 respectively by special-shaped steel. Due to the large thickness of the side walls of the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 and the large sealing contact area with the inlet pressure pipe 20 and the outlet pressure pipe 30, the sealing performance of the slipknot sub-rigid structure expansion joint is guaranteed while the corrosion resistance of the slipknot sub-rigid structure expansion joint is minimally affected.

[0036] Alternatively, as Figure 3 As shown, both the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 are annular. The inner diameter of the inlet corrugated shell disc 40 is not less than the inner diameter of the inlet pressure pipe 20 to prevent the inlet corrugated shell disc 40 from affecting the flow of the medium. The outer diameter of the inlet corrugated shell disc 40 is not greater than the outer diameter of the inlet pressure pipe 20 to avoid interference with the rigid ring 60 and to avoid affecting the sealing connection between the rigid ring 60 and the inlet pressure pipe 20 and the outlet pressure pipe 30. The inner diameter of the outlet corrugated shell disc 80 is equal to the inner diameter of the outlet pressure pipe 30, so that the medium flows smoothly and turbulently at the connection between the outlet corrugated shell disc 80 and the outlet pressure pipe 30. The outer diameter of the outlet corrugated shell disc 80 is not greater than the outer diameter of the outlet pressure pipe 30 to avoid interference with the rigid ring 60 and to avoid affecting the sealing connection between the rigid ring 60 and the inlet pressure pipe 20 and the outlet pressure pipe 30.

[0037] Preferably, if Figure 3 As shown, the material of both the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 is the same as that of the corrugated shell 50. The thin and soft corrugated shell 50 and the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 at its two ends are all made of the same material. Due to the consistency of the materials, the corrosion resistance and service life of the joints at both ends of the corrugated shell 50 are guaranteed. At the same time, it avoids the two ends of the thin and soft surface corrugated shell 50 being directly welded to the inlet pressure pipe 20 and outlet pressure pipe 30 of different materials, preventing damage to the corrugated shell 50 during welding, improving the corrosion resistance and structural performance of the corrugated shell 50, and thus improving the service life of the hydropower station's slipknot-type sub-rigid structure expansion joint. In this preferred embodiment, the inlet corrugated shell disc 40, the outlet corrugated shell disc 80 and the corrugated shell 50 are all made of stainless steel, and the inlet pressure pipe 20 and the outlet pressure pipe 30 are made of the same material, both high-strength steel.

[0038] Alternatively, as Figure 3As shown, the first sealing member 90 and the second sealing member 110 are both sealing rings, and there is only one sealing ring. A concave, annular groove is provided on the outlet-side end surface of the inlet pressure pipe 20, and a sealing ring is positioned within the groove. The outlet-side end surface of the outlet pressure pipe 30 also includes a concave, annular groove, and a sealing ring is positioned within the groove. In other embodiments, there are multiple first fasteners 90 and second fasteners 110. The multiple first fasteners 90 are evenly spaced along the circumference of the inlet corrugated shell 40, with the connecting end of each first fastener 90 extending perpendicularly through the outer end surface of the inlet corrugated shell 40 and into the inlet pressure pipe 20. The multiple second fasteners 110 are evenly spaced along the circumference of the outlet corrugated shell 80, with the connecting end of each second fastener 110 extending perpendicularly through the outer end surface of the outlet corrugated shell 80 and into the outlet pressure pipe 30. Since there are multiple first fasteners 90, the multiple first fasteners 90 are evenly spaced along the circumference of the inlet corrugated shell disk 40, so that the connection between the inlet corrugated shell disk 40 and the inlet pressure pipe 20 is stable, the connection is safe and reliable, and the inlet corrugated shell disk 40 is evenly stressed and in good stress condition, thereby improving the service life of the inlet corrugated shell disk 40; similarly, since there are multiple second fasteners 110, the multiple second fasteners 110 are evenly spaced along the circumference of the outlet corrugated shell disk 80, so that the connection between the outlet corrugated shell disk 80 and the outlet pressure pipe 30 is stable, the connection is safe and reliable, and the outlet corrugated shell disk 80 is evenly stressed and in good stress condition, thereby improving the service life of the outlet corrugated shell disk 80.

[0039] In this option, if Figure 3 As shown, the first fastener 90 and the second fastener 110 are both flange screws, and the first fastener 90 is located below the connection position between the corrugated shell 50 and the inlet corrugated shell plate 40, and the second fastener 110 is located below the connection position between the corrugated shell 50 and the outlet corrugated shell plate 80. Since the first fastener 90 is located below the connection position between the corrugated shell 50 and the inlet corrugated shell plate 40, and the second fastener 110 is located below the connection position between the corrugated shell 50 and the outlet corrugated shell plate 80, it is convenient to weld the two ends of the corrugated shell 50 to the inlet corrugated shell plate 40 and the outlet corrugated shell plate 80, and it is also convenient to install and remove the flange screws.

[0040] Preferably, if Figure 3As shown, the slipknot sub-rigid structure expansion joint also includes a first seal 120 and a second seal 130. The first seal 120 is arranged between the inlet corrugated shell disc 40 and the inlet pressure pipe 20 to seal the gap therebetween. The second seal 130 is arranged between the outlet corrugated shell disc 80 and the outlet pressure pipe 30 to seal the gap therebetween. In the structure of the present invention, the two ends of the corrugated shell 50 are respectively welded to the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 to form a first layer of rigid seal, the first seal 120 is arranged between the inlet corrugated shell disc 40 and the inlet pressure pipe 20, and the second seal 130 is arranged between the outlet corrugated shell disc 80 and the outlet pressure pipe 30 to form a second layer of flexible seal, and the two ends of the rigid ring 60 are respectively sealed to the inlet pressure pipe 20 and the outlet pressure pipe 30 to form a third layer of flexible seal. Through this three-layer sealing structure, the slipknot sub-rigid structure expansion joint and the inlet pressure pipe 20 and the outlet pressure pipe 30 have good sealing performance and are not prone to leakage.

[0041] In this preferred embodiment, if Figure 3 As shown, the first seal 120 and the second seal 130 are both sealing rings, and there are multiple sealing rings. The outlet-side end surface of the inlet pressure pipe 20 is provided with multiple concave, annular grooves, which are arranged concentrically and radially in sequence, and each of which contains a sealing ring. The inlet-side end surface of the outlet pressure pipe 30 is provided with multiple concave, annular grooves, which are arranged concentrically and radially in sequence, and each of which contains a sealing ring. Multiple sealing rings are arranged between the inlet corrugated shell disc 40 and the inlet pressure pipe 20, and multiple sealing rings are arranged between the outlet corrugated shell disc 80 and the outlet pressure pipe 30. While enhancing the second layer of flexible sealing effect, it can also effectively reduce the rigid collision between the inlet corrugated shell disc 40 and the inlet pressure pipe 20, and between the outlet corrugated shell disc 80 and the outlet pressure pipe 30, thereby extending the service life of the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80, and improving the stress state of the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80, so that they work stably, have a long service life, and have a good force transmission effect.

[0042] In this option, if Figure 3As shown, the inlet corrugated shell disc 40 is sealedly connected to the end face of the outlet end of the inlet pressure pipe 20 through the first fastener 90 and the first seal 120, and the outlet corrugated shell disc 80 is sealedly connected to the end face of the inlet end of the outlet pressure pipe 30 through the second fastener 110 and the second seal 130, so that the inlet corrugated shell disc 40 and the inlet pressure pipe 20 form a full ring structure, and the outlet corrugated shell disc 80 and the outlet pressure pipe 30 form a full ring structure, so that the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 support the two ends of the corrugated shell body 50, and can transmit the hydraulic force of the end of the corrugated shell body 50 to the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 at the two ends of the corrugated shell body 50, which are received by the full ring structure with sufficient strength, thereby preventing the corrugated shell body 50 from further stretching and elongating, protecting the end of the corrugated shell body 50, and avoiding damage to the end of the corrugated shell body 50.

[0043] Alternatively, as Figure 3 As shown, the slipknot-type sub-rigid structure expansion joint also includes an anti-wear ring 140 for reducing the wear of the medium on the corrugated shell 50. The anti-wear ring 140 is located inside the inlet corrugated shell disc 40, and the water inlet end of the anti-wear ring 140 is detachably fixed to the inlet corrugated shell disc 40 via a third fastener 150, and the water outlet end of the anti-wear ring 140 extends toward the outlet corrugated shell disc 80. By providing the anti-wear ring 140, the wear of the medium on the inner wall surface of the corrugated shell 50 can be effectively reduced, thereby extending the service life of the corrugated shell 50; the gap between the water outlet end of the anti-wear ring 140 and the outlet corrugated shell disc 80 is used to meet the displacement requirements of the rigid ring 60 in the axial direction; and the gap between the anti-wear ring 140 and the corrugated shell 50 is used to meet the space required for the corrugated section of the corrugated shell 50 to deform in the radial direction when the corrugated shell 50 is compressed.

[0044] In this option, if Figure 3 As shown, the third fastener 150 is a connecting screw. There are multiple connecting screws, evenly spaced along the circumference of the anti-wear ring 140. The connecting end of each connecting screw extends perpendicularly through the inner surface of the anti-wear ring 140 and into the inlet corrugated shell plate 40. The multiple connecting screws and their evenly spaced arrangement along the circumference of the anti-wear ring 140 ensure a stable, secure, and reliable connection between the anti-wear ring 140 and the inlet corrugated shell plate 40. This also ensures that the anti-wear ring 140 is evenly stressed and in good condition, thereby extending the service life of the connection between the anti-wear ring 140 and the inlet corrugated shell plate 40.

[0045] Alternatively, as Figure 3As shown, the slipknot-type sub-rigid structure expansion joint also includes an inlet end pressure plate 160, an outlet end pressure plate 170, a third sealing member 180, and a fourth sealing member 190. The rigid ring 60 is sleeved outside the wave shell 50 at intervals, and the two ends of the rigid ring 60 extend to be sleeved outside the inlet pressure pipe 20 and the outlet pressure pipe 30 at intervals. The inlet end pressure plate 160 is sleeved outside the inlet pressure pipe 20 at intervals and fixed to the first end face of the rigid ring 60, and the outlet end pressure plate 170 is sleeved outside the outlet pressure pipe 30 and fixed to the second end face of the rigid ring 60. The third sealing member 180 is sealingly sleeved on the outer circle of the inlet pressure pipe 20 and is located between the inlet end pressure plate 160 and the rigid ring 60 to seal the gap between the inlet pressure pipe 20 and the rigid ring 60. The fourth seal 190 is sealingly sleeved on the outer circle of the outlet pressure tube 30 and is located between the outlet end pressure plate 170 and the rigid ring 60 to seal the gap between the outlet pressure tube 30 and the rigid ring 60. In this optional solution, the inlet end of the rigid ring 60 forms a movable connection relative to the inlet pressure tube 20 through the inlet end pressure plate 160 and the third seal 180, and the outlet end of the rigid ring 60 also forms a movable connection relative to the outlet pressure tube 30 through the outlet end pressure plate 170 and the fourth seal 190, so that the deformation of the wave shell 50 can be carried out at either end, and the deformation direction of the wave shell 50 is not restricted, thereby facilitating the good transmission of complex forces on the wave shell 50. In this optional solution, the inlet end pressure plate 160 and the outlet end pressure plate 170 can be welded to the two ends of the rigid ring 60, or can be connected to the two ends of the rigid ring 60 by means of connection methods such as clamping and bolting. The third seal 180 and the fourth seal 190 are both sealing rings.

[0046] In this optional solution, the ends of the two ends of the rigid ring 60 are in contact with the outer wall surfaces of the inlet pressure pipe 20 and the outlet pressure pipe 30 respectively, and a certain fitting gap is left, that is, there is a certain radial fitting gap between the inner wall surface of the rigid ring 60 and the outer wall surfaces of the inlet pressure pipe 20 and the outlet pressure pipe 30. While ensuring that the two ends of the rigid ring 60 can slide in the axial direction, the outward wave top of the wave shell 50 is in contact with or tends to contact the inner wall surface of the rigid ring 60, so that when the wave shell 50 is subjected to radial pressure and bulges outward, the rigid ring 60 plays a rigid supporting role for the corrugated shell body 50; since an axial expansion gap is provided between the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80, a corrugated shell body 50 is axially provided in the axial expansion gap, and both ends of the corrugated shell body 50 are sealedly connected to the inlet corrugated shell disc 40 and the outlet corrugated shell disc 80 respectively, and the corrugated shell body 50 provided in the axial expansion gap has axial retractability under the action of external force, while ensuring the sealing of the slipknot-type sub-rigid structure expansion joint, it can meet the axial expansion and contraction of the metal pipe caused by temperature, and effectively eliminate the axial stress of the pipe.

[0047] Alternatively, as Figure 3As shown, the slipknot-type sub-rigid structure expansion joint of the present invention also includes a wave core 70, which is disposed between the inward wave cavity of the wave shell 50 and the rigid ring 60. The wave core 70 can be disposed within the inward wave cavity of the wave shell 50, with the outer wall of the wave core 70 abutting against the inner wall of the rigid ring 60. The inner wall of the wave core 70 is disposed toward the surface of the wave shell 50 and an elastic gap is left between the inner wall of the inward wave cavity. By providing the elastic gap, elastic deformation space is ensured in the inward wave cavity when the telescopic tube is subjected to axial and / or radial forces. It can be understood that the elastic gap is a deformation gap that satisfies the elastic deformation range of the inward wave cavity, that is, the inward wave cavity produces elastic deformation in the elastic gap without destroying the structure of the inward wave cavity. Specifically, by setting a wave core 70 that plays a radial supporting role for the wave shell 50, when the inward wave cavity is subjected to large radial pressure, the top of the inner wall of the inward wave cavity contacts the surface of the wave core 70, and the wave core 70 plays a rigid supporting role for the inward wave cavity. The radial force is transmitted and received by the wave core 70 with sufficient strength to prevent the inward wave cavity from further deformation. Since the inward wave cavity can only produce radial deformation at the elastic gap, the elastic deformation of the inward wave cavity is within an acceptable range, preventing the wave shell 50 from being damaged, thereby ensuring the stability and reliability of the equipment operation. It can be understood that by setting up the rigid ring 60 and the wave core 70 to jointly provide rigid support for the wave shell 50, the stability of the wave shell 50 when subjected to radial pressure is greatly improved, and the thickness of the wave shell 50 can be reduced, thereby improving the impact of stress on the wave shell 50.

[0048] The hydropower station pressure steel pipe sub-rigid structure expansion joint of the present invention is formed by sealing the corrugated shell 50 and the inlet corrugated shell disk 40 and the outlet corrugated shell disk 80 to form a first elastic sealing layer, and the rigid ring 60 and the inlet pressure pipe 20 and the outlet pressure pipe 30 are sealed to form a second elastic sealing layer, so that the corrugated shell 50 is protected by double-layer sealing, and will not cause mutual sealing interference and activity obstruction, thereby forming a double stable sealing combination structure; the two ends of the corrugated shell 50 are respectively sealed and connected to the inlet corrugated shell disk 40 and the outlet corrugated shell disk 80 by welding, and the corrugated shell 50 is sealed and connected to the inlet corrugated shell disk 40 and the corrugated shell 50 is sealed and connected to .... There is an elastic gap between the outlet wave shell disc 80, so that when the wave shell 50 is subjected to complex forces and produces bending deformation, the force is transmitted to the inlet wave shell disc 40 and the outlet wave shell disc 80 through the two ends of the wave shell 50, thereby forming slope protection for the two ends of the wave shell 50; the wave core body 70 is installed in blocks between the inward wave cavity of the wave shell 50 and the rigid ring 60, and there is an elastic gap between the wave shell 50 and the inlet wave shell disc 40, as well as between the wave shell 50 and the outlet wave shell disc 80, so that when the wave shell 50 is subjected to complex forces and produces bending deformation, the force is transmitted to the inlet wave shell disc 40 and the outlet wave shell disc 80 through the two ends of the wave shell 50, respectively. 0 maintains a relative elastic gap between the inner wall surface of the inward wave cavity, so that when the wave shell 50 is subjected to complex forces and produces bending deformation, the force is transmitted to the rigid ring 60 through the wave core 70, forming a protection for the middle slope of the wave shell 50, and the radial medium pressure received by the wave shell 50 can be transmitted to the rigid ring 60 to prevent the wave shell 50 from being damaged. The sub-rigid structure expansion joint of the hydropower station pressure steel pipe has good flexibility, large bearing capacity, zero leakage and long service life; and, since the sub-rigid structure expansion joint of the hydropower station pressure steel pipe mainly includes the wave shell 50, the wave core 70 and the rigid ring 60, the wave shell 50, the wave core 70 and the rigid ring 60 are combined to form The flexible and high-strength tubular sealed telescopic pressure-bearing structure, the water pressure borne by the corrugated shell 50 in the tube is safely and reliably transmitted to the rigid ring 60 through the corrugated core 70, and the wall thickness of the rigid ring 60 is designed in accordance with the design specifications of the pressure steel pipe. Therefore, the hydropower station pressure steel pipe sub-rigid structure expansion joint 100 has the ability to withstand the design pressure value of the same PD value as the established pressure steel pipe. The fully sealed metal corrugated shell structure of the hydropower station pressure steel pipe sub-rigid structure expansion joint 100 not only has good expansion and contraction ability, but also achieves a fully sealed and dripping sealing effect, which completely solves the leakage problem of the transmission expansion joint.

[0049] In this optional solution, the block-shaped wave core 70 is a vibration-absorbing and wear-resistant body, and the wave core 70 is composed of a rigid material covered with a vibration-absorbing and wear-resistant material. It can be understood that the first end of the wave core 70 is against the inner wall surface of the rigid ring 60, and the second end of the wave core 70 is arranged toward the surface of the wave shell 50 and leaves an elastic gap with the surface of the inward wave cavity. Specifically, the vibration-absorbing and wear-resistant material can be a polymer rubber pad, a polymer plastic pad, a corrugated structure buffer pad, an elastic pad, or other buffer pads that can undergo slight deformation or a polymer wear-resistant material; by causing the wear-resistant parts made of the vibration-absorbing and wear-resistant material to undergo compression deformation and transfer to the rigid parts made of the rigid material when the wave core 70 is compressed, sudden force changes on the wave shell 50 are prevented, damage to the wave shell 50 is prevented, and the service life of the wave shell 50 is increased. Furthermore, the cross-section of the wave core 70 is in the shape of an inverted trapezoid, a circle, an ellipse, or a semicircle.

[0050] Preferably, the cross-sectional shape of the wave core 70 matches the cross-sectional shape of the elastic deformation gap of the inward wave cavity, so that the inward wave cavity can generate multiple force support points, and maintain the structural integrity of the inward wave cavity when the inward wave cavity is deformed by force.

[0051] Preferably, the wave cores 70 are multiple, and the wave cores 70 are divided and arranged along the circumference of the rigid ring 60 to fill the inward wave cavity of the wave shell 50. Specifically, the wave cores 70 are evenly spaced or evenly arranged closely along the circumference of the rigid ring 60. It is understood that the number of wave cores 70 can be four, six, or other numbers.

[0052] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A slipknot type sub-rigid structure expansion joint, characterized in that: It is used for connecting the water diversion steel pipe sections of a hydropower station and the water diversion steel pipe sections with the inlet end of a water wheel volute, or for connecting the inlet end of an expansion joint with different pipe diameters and different liquid media such as oil and water with the pressure steel pipe of a hydropower station, and is used for connecting between an inlet pressure pipe (20) and an outlet pressure pipe (30) that are relatively spaced apart. The slipknot sub-rigid structure expansion joint comprises: An inlet corrugated shell disk (40) and an outlet corrugated shell disk (80) arranged relatively spaced apart between the inlet pressure pipe (20) and the outlet pressure pipe (30), a corrugated shell body (50) arranged axially between the inlet corrugated shell disk (40) and the outlet corrugated shell disk (80), a rigid ring (60) sleeved outside the corrugated shell body (50), the inlet corrugated shell disk (40) and the outlet corrugated shell disk (80) and having both ends respectively sleevedly connected to the inlet pressure pipe (20) and the outlet pressure pipe (30), and a corrugated core body (70) filled between the rigid ring (60) and the corrugated shell body (50); The inlet corrugated shell disc (40) is detachably fixed to the inlet pressure pipe (20) via a first fastener (90), and the outlet corrugated shell disc (80) is detachably fixed to the outlet pressure pipe (30) via a second fastener (110); The two ends of the corrugated shell (50) are respectively welded and fixed to the inlet corrugated shell plate (40) and the outlet corrugated shell plate (80); The outer diameter of the penstock is greater than 8.2m; The inlet corrugated shell disc (40) and the outlet corrugated shell disc (80) are both annular; the inner diameter of the inlet corrugated shell disc (40) is not less than the inner diameter of the inlet pressure pipe (20) to avoid the inlet corrugated shell disc (40) affecting the flow of the medium, and the outer diameter of the inlet corrugated shell disc (40) is not greater than the outer diameter of the inlet pressure pipe (20) to avoid interference with the rigid ring (60) and avoid causing damage to the sealing connection between the rigid ring (60) and the inlet pressure pipe (20) and the outlet pressure pipe (30). The inner diameter of the outlet corrugated shell disk (80) is equal to the inner diameter of the outlet pressure pipe (30), so that the medium flows smoothly at the connection between the outlet corrugated shell disk (80) and the outlet pressure pipe (30) without generating turbulence, and the outer diameter of the outlet corrugated shell disk (80) is not greater than the outer diameter of the outlet pressure pipe (30), so as to avoid interference with the rigid ring (60) and avoid affecting the sealing connection between the rigid ring (60) and the inlet pressure pipe (20) and the outlet pressure pipe (30); The material of both the inlet corrugated shell disc (40) and the outlet corrugated shell disc (80) is the same as the material of the corrugated shell (50); The slipknot-type sub-rigid structure expansion joint further includes a first sealing member (120) and a second sealing member (130); the first sealing member (120) is arranged between the inlet corrugated shell disc (40) and the inlet pressure pipe (20) to seal the gap therebetween; the second sealing member (130) is arranged between the outlet corrugated shell disc (80) and the outlet pressure pipe (30) to seal the gap therebetween; The slipknot-type sub-rigid structure expansion joint further comprises an inlet end pressure plate (160), an outlet end pressure plate (170), a third sealing member (180) and a fourth sealing member (190); the rigid body ring (60) is sleeved outside the wave shell (50) at intervals, and both ends of the rigid body ring (60) are respectively extended to be sleeved outside the inlet pressure pipe (20) and the outlet pressure pipe (30); the inlet end pressure plate (160) is sleeved outside the inlet pressure pipe (20) at intervals and fixed to the first end face of the rigid body ring (60); the outlet end pressure plate (170) is sleeved on the outlet pressure pipe ( The third sealing member (180) is sealingly sleeved on the outer circle of the inlet pressure pipe (20) and is located between the inlet end pressure plate (160) and the rigid ring (60) to seal the gap between the inlet pressure pipe (20) and the rigid ring (60); the fourth sealing member (190) is sealingly sleeved on the outer circle of the outlet pressure pipe (30) and is located between the outlet end pressure plate (170) and the rigid ring (60) to seal the gap between the outlet pressure pipe (30) and the rigid ring (60).

2. The slipknot sub-rigid structure expansion joint according to claim 1, characterized in that: The first fastener (90) and the second fastener (110) are both in multiple pieces; A plurality of first fasteners (90) are evenly spaced along the circumference of the inlet corrugated shell disk (40), and a connection end of each first fastener (90) is perpendicularly passed through the inlet corrugated shell disk (40) from the outer end surface of the inlet corrugated shell disk (40) and then extends into the inlet pressure pipe (20); A plurality of second fasteners (110) are evenly spaced along the circumference of the outlet corrugated shell disc (80), and a connection end of each second fastener (110) passes through the outlet corrugated shell disc (80) perpendicularly from the outer end surface of the outlet corrugated shell disc (80) and then extends into the outlet pressure pipe (30).

3. The slipknot sub-rigid structure expansion joint according to claim 2, characterized in that: The first fastener (90) and the second fastener (110) are both flange screws, and the first fastener (90) is located below the connection position between the corrugated shell (50) and the inlet corrugated shell disk (40), and the second fastener (110) is located below the connection position between the corrugated shell (50) and the outlet corrugated shell disk (80).

4. The slipknot sub-rigid structure expansion joint according to claim 1, characterized in that: The first sealing member (120) and the second sealing member (130) are both sealing rings, and the number of the sealing rings is one; An annular groove with an inward concave shape and an annular shape is provided on the water outlet side end surface of the inlet pressure pipe (20), and the sealing ring is provided in the annular groove; an annular groove with an inward concave shape and an annular shape is provided on the water inlet side end surface of the outlet pressure pipe (30), and the sealing ring is provided in the annular groove.

5. The slipknot sub-rigid structure expansion joint according to claim 1, characterized in that: The slipknot-type sub-rigid structure expansion joint further includes an anti-wear ring (140) for reducing wear of the wave shell (50) by the medium; The anti-wear ring (140) is located inside the inlet corrugated shell disc (40), and the water inlet end of the anti-wear ring (140) is detachably fixed to the inlet corrugated shell disc (40) via a third fastener (150), and the water outlet end of the anti-wear ring (140) extends toward the outlet corrugated shell disc (80).

6. The slipknot sub-rigid structure expansion joint according to claim 5, characterized in that: The third fastener (150) is a connecting screw, and there are a plurality of the connecting screws, which are evenly spaced along the circumference of the anti-wear ring (140); The connecting end of each connecting screw is perpendicularly passed through the anti-wear ring (140) from the inner ring surface of the anti-wear ring (140) and then extends into the inlet corrugated shell disk (40).

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