Expansion joint for tubular heat exchanger

Abstract

The invention relates to the technical field of pipeline connectors, in particular to an expansion joint for a shell-and-tube heat exchanger, which comprises a shell-and-tube heat exchanger body, a connecting type flange plate is coaxially and fixedly mounted on the shell-and-tube heat exchanger body, and an annular limiting strip and an annular positioning strip are arranged on the inner wall of the connecting type flange plate along the circumferential direction; an annular embedded strip is movably installed on the inner wall of the annular positioning strip in a clamped mode, countersunk bolts are arranged on the annular embedded strip, and the annular embedded strip is fixedly installed on the annular positioning strip through the countersunk bolts. Liquid flowing in the inner expansion pipe can enter a cavity formed by the inner expansion pipe, the annular sliding strip, the second annular connecting strip and the outer expansion pipe through the pressure relief holes, and pressure generated in the flowing process of the liquid can be shared by the cavity formed by the inner expansion pipe, the annular sliding strip, the second annular connecting strip and the outer expansion pipe. The pressure generated by liquid flowing is reduced, the pressure borne by the expansion joint is effectively reduced, damage or failure of the expansion joint caused by overhigh stress is avoided, and the service life of the expansion joint is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline interfaces, in particular to an expansion joint for a shell-and-tube heat exchanger. Background Art

[0002] The working principle of the shell and tube heat exchanger is as follows: the hot fluid and the cold fluid flow through the tube bundle and outside the tube bundle of the heat exchanger respectively (or vice versa). The hot fluid transfers heat to the cold fluid through the tube wall. Specifically, when the hot fluid flows in the tube, the heat is transferred to the outside of the tube through the metal tube wall. At the same time, due to the temperature difference between the fluids, heat convection will occur, further promoting the transfer of heat. When the cold fluid flows outside the tube, it continuously absorbs heat from the tube wall, so that its own temperature rises, while the temperature of the hot fluid gradually decreases. In this way, the heat exchange between the two fluids is realized, achieving the purpose of heat exchange.

[0003] The expansion joints used in shell-and-tube heat exchangers have the following main functions: Compensation for displacement: compensate for the axial, lateral and angular displacement of the pipeline caused by temperature changes, thermal expansion and contraction of the pipeline, etc., to prevent the pipeline from being damaged due to deformation; Absorb vibration: reduce the vibration transmission in the pipeline system, reduce the impact of vibration on equipment and pipelines, and extend the life of the equipment; Reduce stress: reduce stress concentration at the pipeline connection through its own expansion and contraction, avoid cracks and other problems; Ensure pipeline safety: ensure that the pipeline can operate safely and stably under various working conditions, and reduce safety hazards such as leakage.

[0004] When the expansion joint is used on a shell-and-tube heat exchanger, since the shell-and-tube heat exchanger contains hot and cold water, the temperature difference between hot and cold in the shell-and-tube heat exchanger is greater than that of ordinary pipes. Therefore, the shell-and-tube heat exchanger needs an expansion joint with better compensation capability to alleviate the deformation of the shell-and-tube heat exchanger due to temperature changes and thermal expansion and contraction of the pipes. When traditional expansion joints are used in shell-and-tube heat exchangers, their service life is relatively low. In order to solve this problem, a new expansion joint for shell-and-tube heat exchangers is proposed. Summary of the invention

[0005] The object of the present invention is to provide an expansion joint for a shell-and-tube heat exchanger to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an expansion joint for a shell-and-tube heat exchanger, comprising a shell-and-tube heat exchanger body, a connecting flange is coaxially fixedly installed on the shell-and-tube heat exchanger body, an annular limiting strip and an annular positioning strip are circumferentially arranged on the inner wall of the connecting flange, an annular embedding strip is movably mounted on the inner wall of the annular positioning strip, a countersunk bolt is arranged on the annular embedding strip, and the annular embedding strip is fixedly installed on the annular positioning strip by the countersunk bolt, and a first annular connecting strip is arranged on the side close to the two annular embedding strips, and the first A pressure relief hole is provided on the annular connecting strip, the side walls of the first annular connecting strip and the annular positioning strip are fitted together, an inner expansion tube is arranged between the two first annular connecting strips, an annular sliding strip is movably engaged in the structure composed of the annular limiting strip and the annular positioning strip, a second annular connecting strip is arranged on the side close to each other, the circumferential inner side wall of the second annular connecting strip is fitted together with the circumferential outer side wall of the first annular connecting strip, an outer expansion tube is arranged between the two second annular connecting strips, and the outer expansion tube structure is located outside the second annular connecting strip structure.

[0007] Preferably, the pressure relief holes on the first annular connecting strip are distributed in an annular array with the central axis of the first annular connecting strip as the center of the array.

[0008] Preferably, the inner expansion tube and the outer expansion tube are coaxially arranged, and the corrugations on the outer expansion tube and the inner expansion tube have the same interval.

[0009] Preferably, the first annular connecting strip, the inner expansion tube, the second annular connecting strip and the outer expansion tube form a sealed cavity.

[0010] Preferably, the outer wall of the second annular connecting strip is fixedly connected to a driving push rod, and a guide bracket is provided on the side wall of the connecting flange close to the second annular connecting strip, and the guide bracket is movably mounted outside the driving push rod, and a U-shaped clip is fixedly installed on the driving push rod, and the U-shaped clip is movably mounted on the guide bracket, and a locking bolt supported at a corresponding position of the guide bracket is threadedly connected to the U-shaped clip, and an L-shaped shielding member is provided at the position of the pressure relief hole on the inner side wall of the second annular connecting strip.

[0011] Preferably, the guide bracket is arranged along an arc corresponding to the central axis of the second annular connecting strip, and the guide bracket is located between two adjacent mounting holes on the connecting flange.

[0012] Preferably, the annular embedding strip and the first annular connecting strip are an integrally formed structure, and the circumferential inner side walls of the annular embedding strip and the first annular connecting strip are flush.

[0013] Preferably, an internal and external threaded sleeve is movably installed on the connecting flange, and a hexagonal bolt is threadedly connected to the internal and external threaded sleeve, and the hexagonal bolt is located on both sides of the connecting flange. An adjusting screw is internally threadedly connected to the hexagonal bolt, and a positioning ring is fixedly installed on the end of the adjusting screw. The positioning ring is located in another internal and external threaded sleeve and is rotatably connected to the internal and external threaded sleeve, and a driving handle is provided on the end of the adjusting screw.

[0014] Preferably, the internal and external threaded sleeves at other positions may be connected via a telescopic rod.

[0015] Preferably, the inner side of the inner expansion tube is connected via an annular flow blocking strip, and the annular flow blocking strip is flush with the circumferential inner side wall of the annular positioning strip.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. When the bearing capacity of the expansion joint needs to be increased, the locking bolt is turned so that the locking bolt no longer applies pressure to the side wall of the guide bracket to ensure that the U-shaped buckle can move on the guide bracket. The driving push rod is pressed to drive the U-shaped buckle to move on the guide bracket. During the movement of the driving push rod, the driving push rod will drive the second annular connecting strip to move in the corresponding direction. During the movement of the second annular connecting strip, the annular sliding strip is driven by the second annular connecting strip to rotate inside the annular limiting strip and the annular positioning strip, so as to realize the rotation of the outer expansion tube on the surface of the inner expansion tube. At the same time, the rotation of the second annular connecting strip will also drive the movement of the L-shaped shielding member. The L-shaped shielding piece moves away from the pressure relief hole, so that the pressure relief hole is exposed, and the liquid flowing in the inner expansion tube will enter the cavity formed by the inner expansion tube, the annular sliding strip, the second annular connecting strip and the outer expansion tube through the pressure relief hole. The pressure generated during the flow of liquid will be shared by the cavity formed by the inner expansion tube, the annular sliding strip, the second annular connecting strip and the outer expansion tube, thereby reducing the pressure generated by the flow of liquid, effectively reducing the pressure on the expansion joint, avoiding damage or failure of the expansion joint due to excessive stress, extending its service life, providing better buffer space, allowing pressure changes to be transmitted and dissipated more smoothly, and reducing the impact on surrounding structures.

[0017] 2. Insert the ends of the internal and external threaded sleeves into the flange and the connecting flange on the shell and tube heat exchanger body, and fix them with hexagonal bolts. By selection, install the adjusting screw between the corresponding internal and external threaded sleeves, and set the telescopic rod between other internal and external threaded sleeves. The positioning ring on the end of the driving handle is driven to rotate in the internal and external threaded sleeves by rotating the driving handle. During the rotation of the adjusting screw, the adjusting screw will move in the internal and external threaded sleeves threadedly connected to the adjusting screw, thereby driving the two internal and external threaded sleeves to approach or move away from each other to adjust the distance between the two parts of the shell and tube heat exchanger body. By the mutual approach of the two internal and external threaded sleeves at this position, the other internal and external threaded sleeves are driven to approach each other. At the same time, the distance between the internal and external threaded sleeves is adjusted, thereby changing the stress of the expansion joint and extending its service life. According to specific working conditions, such as changes in temperature, pressure, flow, etc., the state of the expansion joint can be flexibly adjusted to make it better adapt to various complex working conditions.

[0018] 3. Through the double-layer structure composed of the inner expansion tube and the outer expansion tube, when the tube body of the shell-and-tube heat exchanger is subjected to axial, lateral and angular displacement of the tube due to temperature changes, thermal expansion and contraction of the tube, the structure composed of the inner expansion tube and the outer expansion tube can be deformed in double layers to adapt to the axial, lateral and angular displacement of the tube caused by temperature changes, thermal expansion and contraction of the tube, and improve the stress resistance. Compared with the single-layer expansion joint, the two-layer structure helps to improve the sealing effect, reduce the possibility of leakage, ensure the tightness of the system, withstand higher pressure, and work stably under high-pressure environment to ensure system safety.

[0019] 4. The annular baffle belt guides the flow of the liquid to prevent the liquid from directly contacting the inner wall of the inner expansion tube, affecting the flow effect of the liquid, and preventing the inner expansion tube from directly contacting the liquid. At the same time, the annular baffle belt has a certain deformation capacity to adapt to the deformation of the inner expansion tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the installation structure of the present invention.

[0021] Figure 2 It is a front view structural schematic diagram of the present invention.

[0022] Figure 3 It is a schematic diagram of the structure of the present invention from a top view.

[0023] Figure 4 It is a schematic diagram of the structure of the present invention from a side view.

[0024] Figure 5 It is a structural schematic diagram of the corresponding position of the hexagonal bolt of the present invention.

[0025] Figure 6 It is a structural schematic diagram of the corresponding position of the twisting screw rod of the present invention.

[0026] Figure 7 It is a schematic diagram of the structure at the corresponding position of the inner expansion tube of the present invention.

[0027] Figure 8 It is a schematic diagram of the cross-sectional structure of the inner expansion tube and the outer expansion tube of the present invention.

[0028] Fig. 9 It is a structural schematic diagram of the corresponding position of the driving push rod of the present invention.

[0029] Fig.10 It is a schematic diagram of the structure at the corresponding position of the connecting flange of the present invention.

[0030] Fig.11 It is a structural schematic diagram of the corresponding position of the cross section of the internal expansion tube of the present invention.

[0031] Fig.12 It is a schematic diagram of the structure of the corresponding position of the annular connecting belt of the present invention.

[0032] Fig.13 It is a schematic diagram of the structure at the corresponding position of the leakage hole of the present invention.

[0033] Fig.14 It is a schematic diagram of the structure at the corresponding position of the annular baffle belt of the present invention.

[0034] In the figure: 1. Shell and tube heat exchanger body; 2. Connecting flange; 3. Annular limit strip; 4. Annular positioning strip; 5. Annular embedding strip; 501. Countersunk bolt; 6. First annular connecting strip; 601. Pressure relief hole; 7. Inner expansion tube; 8. Annular sliding strip; 9. Second annular connecting strip; 901. L-shaped shielding piece; 10. Outer expansion tube; 11. Driving push rod; 12. Guide bracket; 13. U-shaped buckle; 14. Locking bolt; 15. Internal and external threaded sleeves; 16. Hexagonal bolt; 17. Adjusting screw; 18. Positioning ring; 19. Driving handle; 20. Telescopic rod; 21. Annular flow blocking belt. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figures 1 to 14The present invention provides a technical solution: an expansion joint for a shell-and-tube heat exchanger, comprising a shell-and-tube heat exchanger body 1, the shell-and-tube heat exchanger body 1 is the body of the shell-and-tube heat exchanger, the shell-and-tube heat exchanger body 1 is composed of two parts, the two parts are connected by a connecting flange 2 and a structure on the connecting flange 2, and the assembly of auxiliary equipment, the shell-and-tube heat exchanger body 1 mainly utilizes the principle of heat exchange between two fluids of different temperatures inside and outside the tube bundle to exchange heat, a connecting flange 2 is coaxially fixedly installed on the shell-and-tube heat exchanger body 1, the connecting flange 2 corresponds to the flange at the corresponding position on the shell-and-tube heat exchanger body 1, and the two are fixedly connected by bolts, and the inner wall of the connecting flange 2 is circumferentially provided with an annular limiting strip 3 and an annular positioning strip 4 The annular limiting strip 3 and the annular positioning strip 4 are installed on the inner wall of the circumference of the connecting flange 2. The annular limiting strip 3 is an annular strip, and the annular positioning strip 4 is an L-shaped strip in cross section. The inner wall of the annular positioning strip 4 is movably engaged with an annular embedding strip 5, and the annular embedding strip 5 is provided with a countersunk bolt 501, and the annular embedding strip 5 is fixedly installed on the annular positioning strip 4 by the countersunk bolt 501. The annular embedding strip 5 is an annular belt, and a yield groove corresponding to the shape of the annular embedding strip 5 is provided on the annular positioning strip 4. The annular embedding strip 5 is movably engaged in the groove body on the annular positioning strip 4, and the two are movably connected, and the annular positioning strip 4 is also provided with a threaded mounting hole corresponding to the countersunk bolt 501, which assists the installation of the countersunk bolt 501 on the annular positioning strip 4. , thereby ensuring the connection and fixation between the annular positioning strip 4 and the annular embedding strip 5, ensuring the fixing effect of the annular embedding strip 5 on the annular positioning strip 4, a first annular connecting strip 6 is provided on the side close to the two annular embedding strips 5, the annular embedding strip 5 and the first annular connecting strip 6 are an integrally formed structure, the annular embedding strip 5 and the first annular connecting strip 6 are integrally formed, and the manufacturing convenience of the structure composed of the annular embedding strip 5 and the first annular connecting strip 6 is improved through the integrally formed injection molding process, and the circumferential inner side walls of the annular embedding strip 5 and the first annular connecting strip 6 are flush, ensuring that the fluid will not be subject to angle resistance when passing through the position of the annular embedding strip 5 and the first annular connecting strip 6, ensuring that the liquid is properly positioned at the position of the annular embedding strip 5 and the first annular connecting strip 6 Normal flow, a pressure relief hole 601 is opened on the first annular connecting strip 6, and the pressure relief hole 601 is a groove penetrating the first annular connecting strip 6. Part of the liquid in the pressure relief hole 601 is introduced into the sealed cavity composed of the first annular connecting strip 6, the inner expansion tube 7, the second annular connecting strip 9 and the outer expansion tube 10. The first annular connecting strip 6, the inner expansion tube 7, the second annular connecting strip 9 and the outer expansion tube 10 form a sealed cavity. The liquid enters the sealed cavity composed of the first annular connecting strip 6, the inner expansion tube 7, the second annular connecting strip 9 and the outer expansion tube 10 to buffer the pressure of the liquid in the shell-and-tube heat exchanger body 1 to prevent the inner expansion tube 7 and the outer expansion tube 10 from being subjected to excessive pressure, which exceeds the maximum value of the pressure of the structure composed of the inner expansion tube 7 and the outer expansion tube 10.The buffer pressure is increased by the cooperation of the first annular connecting strip 6, the inner expansion tube 7, the second annular connecting strip 9 and the outer expansion tube 10. The pressure relief holes 601 on the first annular connecting strip 6 are distributed in an annular array with the central axis of the first annular connecting strip 6 as the array center. The position distribution of the pressure relief holes 601 is reasonable, and the liquid in the first annular connecting strip 6 and the inner expansion tube 7 is better discharged, and enters the sealed cavity formed by the first annular connecting strip 6, the inner expansion tube 7, the second annular connecting strip 9 and the outer expansion tube 10, and the liquid flows more reasonably.

[0037] The side walls of the first annular connecting strip 6 and the annular positioning strip 4 fit together to ensure that the gap between the first annular connecting strip 6 and the annular positioning strip 4 is blocked to prevent liquid from leaving through the gap between the annular positioning strip 4 and the first annular connecting strip 6, affecting the sealing effect. An inner expansion tube 7 is arranged between the two first annular connecting strips 6. The inner expansion tube 7 is an expansion structure composed of multiple arc-shaped plates. An annular sliding strip 8 is movably engaged in the structure composed of the annular limiting strip 3 and the annular positioning strip 4. The annular sliding strip 8 is movably engaged in the L-shaped space. The annular sliding strip 8 is movably engaged in the L-shaped space. The sliding of the annular sliding strip 8 in the structure composed of the annular limiting strip 3 and the annular positioning strip 4 is realized by the sliding of the annular sliding strip 8 in the structure composed of the annular limiting strip 3 and the annular positioning strip 4. The sliding of the structure composed of the annular sliding strip 8, the second annular connecting strip 9 and the outer expansion tube 10 is realized. A second annular connecting strip 9 is arranged on the side close to the two annular sliding strips 8. The second annular connecting strip 9 is an L-shaped structure, and the first annular connecting strip 6 is also an L-shaped structure. , through the cooperation of the first annular connecting strip 6 and the second annular connecting strip 9, a U-shaped structure is formed, and the first annular connecting strip 6 and the second annular connecting strip 9 form a structure used to fix the inner expansion tube 7 and the outer expansion tube 10 respectively, and the circumferential inner wall of the second annular connecting strip 9 fits with the circumferential outer wall of the first annular connecting strip 6 to ensure the sealing at the connection position of the first annular connecting strip 6 and the second annular connecting strip 9 to prevent liquid from leaking out from the connection position of the first annular connecting strip 6 and the second annular connecting strip 9. An outer expansion tube 10 is arranged between the two second annular connecting strips 9, and the outer expansion tube 10 structure is located outside the second annular connecting strip 9 structure. The outer expansion tube 10 and the second annular connecting strip 9 form two sets of expansion structures, one outside and one inside, to buffer the expansion stress. Through the design of the inner expansion tube 7 and the outer expansion tube 10, the stress is better relieved. The inner expansion tube 7 and the outer expansion tube 10 are coaxially arranged, and the corrugations on the outer expansion tube 10 and the inner expansion tube 7 are at the same interval.

[0038] The outer wall of the second annular connecting strip 9 is fixedly connected with a driving push rod 11. The position of the driving push rod 11 does not correspond to the position of the mounting hole on the connecting flange 2, giving the driving push rod 11 sufficient moving space to ensure the movement range of the driving push rod 11. A guide bracket 12 is provided on the side wall of the connecting flange 2 close to the second annular connecting strip 9. The guide bracket 12 is a U-shaped bracket, which limits the movement trajectory of the driving push rod 11 and ensures the movement range of the driving push rod 11. The guide bracket 12 is movably mounted outside the driving push rod 11. A U-shaped buckle 13 is fixedly installed on the driving push rod 11. The U-shaped buckle 13 is movably sleeved on the guide bracket 12. The shapes of the U-shaped buckle 13 and the guide bracket 12 are adapted to each other. By sliding the U-shaped buckle 13 on the guide bracket 12, the driving push rod 11 is effectively prevented from sliding. The present invention guides and positions the driving push rod 11 during its movement to ensure the movement stability of the driving push rod 11. When the driving push rod 11 moves, it drives the second annular connecting strip 9, the annular sliding strip 8 and the outer expansion tube 10 to rotate. The U-shaped buckle 13 is threadedly connected with a locking bolt 14 supported at the corresponding position of the guide bracket 12. The locking bolt 14 is threadedly moved on the guide bracket 12 so that the end of the locking bolt 14 applies pressure to the side wall of the guide bracket 12 to achieve the fixation of the driving push rod 11 and the U-shaped buckle 13 after the position adjustment. An L-shaped shielding member 901 is provided at the position of the pressure relief hole 601 corresponding to the inner wall of the second annular connecting strip 9. The position of the L-shaped shielding member 901 corresponds to the position of the pressure relief hole 601, so as to achieve the control or cancellation of the shielding of the pressure relief hole 601 by the L-shaped shielding member 901.

[0039] The guide bracket 12 is arranged along the arc corresponding to the central axis of the second annular connecting strip 9, and the guide bracket 12 is located between two adjacent mounting holes on the connecting flange 2, ensuring the guiding effect of the guide bracket 12 on the U-shaped buckle 13, limiting the moving trajectory of the driving push rod 11, and ensuring the stable movement of the driving push rod 11.

[0040] An internal and external threaded sleeve 15 is movably installed on the connecting flange 2. The internal and external threaded sleeve 15 consists of two parts: a threaded part and an unthreaded part. A hexagonal bolt 16 is threadedly installed on the equipment threaded part. Through the existence of the hexagonal bolt 16, the flange on the shell and tube heat exchanger body 1 and the connecting flange 2 are fixed together. The internal and external threaded sleeve 15 is threadedly connected with the hexagonal bolt 16. The hexagonal bolt 16 is located on both sides of the connecting flange 2. The hexagonal bolt 16 is internally threaded with an adjusting screw 17. A positioning ring 18 is fixedly installed on the end of the adjusting screw 17. A groove corresponding to the positioning ring 18 is provided on the internal and external threaded sleeve 15 to realize the rotational connection and cooperation between the adjusting screw 17 and the internal and external threaded sleeve 15. The positioning ring 18 is located in another internal and external threaded sleeve 15 and is rotationally connected to the internal and external threaded sleeve 15. A driving handle 19 is provided on the end of the adjusting screw 17. The existence of the driving handle 19 is used to assist the rotation of the adjusting screw 17.

[0041] The internal and external threaded sleeves 15 at other positions can also be connected by a telescopic rod 20. According to different positions, the telescopic rod 20 or the adjusting screw 17 can be installed. Only one adjusting screw 17 is needed to adjust all the internal and external threaded sleeves 15.

[0042] The inner side of the inner expansion tube 7 is connected by an annular flow-blocking belt 21, and the annular flow-blocking belt 21 is flush with the inner circumferential wall of the annular positioning strip 4. The existence of the annular flow-blocking belt 21 guides the flow of the liquid to prevent the liquid from directly contacting the inner wall of the inner expansion tube 7 and affecting the flow effect of the liquid. At the same time, the annular flow-blocking belt 21 has a certain deformation ability to adapt to the deformation of the inner expansion tube 7.

[0043] Working principle: The first step: insert the end of the internal and external threaded sleeve 15 into the flange and the connecting flange plate 2 on the shell and tube heat exchanger body 1, and fix it with the hexagonal bolt 16. By selection, install the adjusting screw 17 between the corresponding internal and external threaded sleeves 15, and set the telescopic rod 20 between the other internal and external threaded sleeves 15. The positioning ring 18 on the end of the driving handle 19 is driven to rotate in the internal and external threaded sleeve 15 by rotating the driving handle 19. During the rotation of the adjusting screw 17, the adjusting screw 17 will move in the internal and external threaded sleeve 15 threadedly connected to the adjusting screw 17, thereby driving the two internal and external threaded sleeves 15 to approach or move away from each other to adjust the distance between the two parts of the shell and tube heat exchanger body 1. By the mutual approach of the two internal and external threaded sleeves 15 at this position, the other internal and external threaded sleeves 15 are driven to approach each other. At the same time, the distance between the internal and external threaded sleeves 15 is adjusted to change the stress of the expansion joint.

[0044] Step 2: When the bearing capacity of the expansion joint needs to be increased, the locking bolt 14 is turned so that the locking bolt 14 no longer applies pressure to the side wall of the guide bracket 12, ensuring that the U-shaped buckle 13 can move on the guide bracket 12, and the driving push rod 11 is pressed to drive the U-shaped buckle 13 to move on the guide bracket 12. During the movement of the driving push rod 11, the driving push rod 11 will drive the second annular connecting strip 9 to move in the corresponding direction. During the movement of the second annular connecting strip 9, the annular sliding strip 8 is driven by the second annular connecting strip 9 to rotate inside the annular limiting strip 3 and the annular positioning strip 4 to achieve external expansion. The rotation of the expansion tube 10 on the surface of the inner expansion tube 7 and the rotation of the second annular connecting strip 9 will also drive the movement of the L-shaped shielding member 901, and the L-shaped shielding member 901 will leave the pressure relief hole 601, so that the pressure relief hole 601 is exposed, and the liquid flowing in the inner expansion tube 7 will enter the cavity formed by the inner expansion tube 7, the annular sliding strip 8, the second annular connecting strip 9 and the outer expansion tube 10 through the pressure relief hole 601. The pressure generated during the flow of the liquid will be shared by the cavity formed by the inner expansion tube 7, the annular sliding strip 8, the second annular connecting strip 9 and the outer expansion tube 10, thereby reducing the pressure generated by the liquid flow.

[0045] Step 3: Through the inner and outer double-layer structure composed of the inner expansion tube 7 and the outer expansion tube 10, when the tube body 1 of the shell and tube heat exchanger causes axial, lateral and angular displacement of the pipeline due to temperature changes, thermal expansion and contraction of the pipeline, the structure composed of the inner expansion tube 7 and the outer expansion tube 10 can undergo double-layer deformation to adapt to the axial, lateral and angular displacement of the pipeline caused by temperature changes, thermal expansion and contraction of the pipeline, etc., and improve the stress resistance.

[0046] Step 4: Through the existence of the annular flow-blocking belt 21, the flow of the liquid is guided to prevent the liquid from directly contacting the inner wall of the inner expansion tube 7, affecting the flow effect of the liquid, and preventing the inner expansion tube 7 from directly contacting the liquid. At the same time, the annular flow-blocking belt 21 has a certain deformation ability to adapt to the deformation of the inner expansion tube 7.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An expansion joint for a shell-and-tube heat exchanger, comprising a shell-and-tube heat exchanger body (1), a connecting flange (2) being coaxially fixedly mounted on the shell-and-tube heat exchanger body (1), characterized in that: The inner wall of the connecting flange (2) is provided with an annular limiting strip (3) and an annular positioning strip (4) along the circumferential direction; the inner wall of the annular positioning strip (4) is movably engaged with an annular embedding strip (5); the annular embedding strip (5) is provided with a countersunk bolt (501), and the annular embedding strip (5) is fixedly installed on the annular positioning strip (4) by means of the countersunk bolt (501); a first annular connecting strip (6) is provided on one side of the two annular embedding strips (5) that are close to each other; a pressure relief hole (601) is provided on the first annular connecting strip (6); and the first annular connecting strip (6) and the annular positioning strip (4) are connected to each other. ), an inner expansion tube (7) is arranged between the two first annular connecting strips (6), an annular sliding strip (8) is movably engaged in the structure composed of the annular limiting strip (3) and the annular positioning strip (4), a second annular connecting strip (9) is arranged on the side close to the two annular sliding strips (8), the circumferential inner wall of the second annular connecting strip (9) is in contact with the circumferential outer wall of the first annular connecting strip (6), an outer expansion tube (10) is arranged between the two second annular connecting strips (9), and the structure composed of the outer expansion tube (10) is located outside the structure composed of the second annular connecting strip (9).

2. An expansion joint for a shell-and-tube heat exchanger according to claim 1, characterized in that: The pressure relief holes (601) on the first annular connecting strip (6) are distributed in an annular array with the central axis of the first annular connecting strip (6) as the array center.

3. The expansion joint for a shell-and-tube heat exchanger according to claim 1, characterized in that: The inner expansion tube (7) and the outer expansion tube (10) are coaxially arranged, and the corrugations on the outer expansion tube (10) and the inner expansion tube (7) have the same interval.

4. The expansion joint for a shell-and-tube heat exchanger according to claim 1, characterized in that: The first annular connecting strip (6), the inner expansion tube (7), the second annular connecting strip (9) and the outer expansion tube (10) form a sealed cavity.

5. An expansion joint for a shell-and-tube heat exchanger according to claim 4, characterized in that: The outer wall of the second annular connecting strip (9) is fixedly connected to a driving push rod (11); a guide bracket (12) is arranged on the side wall of the connecting flange (2) close to the second annular connecting strip (9); the guide bracket (12) is movably mounted outside the driving push rod (11); a U-shaped buckle (13) is fixedly mounted on the driving push rod (11); the U-shaped buckle (13) is movably sleeved on the guide bracket (12); a locking bolt (14) supported at a corresponding position of the guide bracket (12) is threadedly connected to the U-shaped buckle (13); and an L-shaped shielding member (901) is arranged at a position of the inner side wall of the second annular connecting strip (9) corresponding to the pressure relief hole (601).

6. An expansion joint for a shell-and-tube heat exchanger according to claim 5, characterized in that: The guide bracket (12) is arranged along an arc corresponding to the central axis of the second annular connecting strip (9), and the guide bracket (12) is located between two adjacent mounting holes on the connecting flange (2).

7. An expansion joint for a shell-and-tube heat exchanger according to claim 6, characterized in that: The annular embedding strip (5) and the first annular connecting strip (6) are an integrally formed structure, and the circumferential inner side walls of the annular embedding strip (5) and the first annular connecting strip (6) are flush.

8. An expansion joint for a shell-and-tube heat exchanger according to claim 7, characterized in that: An internal and external threaded sleeve (15) is movably mounted on the connecting flange (2), and a hexagonal bolt (16) is threadedly connected to the internal and external threaded sleeve (15). The hexagonal bolt (16) is located on both sides of the connecting flange (2). An adjusting screw (17) is internally threadedly connected to the hexagonal bolt (16), and a positioning ring (18) is fixedly mounted on the end of the adjusting screw (17). The positioning ring (18) is located in another internal and external threaded sleeve (15) and is rotatably connected to the internal and external threaded sleeve (15). A driving handle (19) is provided on the end of the adjusting screw (17).

9. An expansion joint for a shell-and-tube heat exchanger according to claim 8, characterized in that: The internal and external threaded sleeves (15) at other locations may also be connected via a telescopic rod (20).

10. An expansion joint for a shell-and-tube heat exchanger according to claim 9, characterized in that: The inner side of the inner expansion tube (7) is connected via an annular flow blocking strip (21), and the annular flow blocking strip (21) is flush with the inner circumferential wall of the annular positioning strip (4).

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