Supporting structure of winding-out section of lateral tube plate

Abstract

A supporting structure of a winding-out section of a lateral tube plate comprises a shell pass cylinder body, a shell pass cylinder body, a shell pass cylinder body and a shell pass cylinder body, the central cylinder is arranged in the shell pass cylinder along the axial direction; the multiple heat exchange tubes are arranged in the shell pass barrel in the axial direction and spirally wound around the periphery of the center barrel from inside to outside to form a multi-layer spiral tube, each layer of spiral tube is provided with a spiral section and a winding-out section in the axial direction, the spiral section and the winding-out section are connected, and the winding-out section is bent and extends towards the lateral tube plate from the end of the spiral section and then is supported on the lateral tube plate; the first connecting piece is composed of a plurality of first connecting sleeves, all the first connecting sleeves are arranged on the peripheries of the winding-out sections of all the layers of spiral pipes in a sleeving mode respectively, the outer wall faces of the first connecting sleeves adjacent to each other inside and outside are connected so that the first connecting piece can be integrally in a strip shape, and the outer wall face of the first connecting sleeve located on the innermost side is connected with the center cylinder. Compared with the prior art, the risk of flow-induced vibration can be reduced.

Description

A support structure for a lateral tube sheet bypass section Technical Field

[0001] This utility model belongs to the field of heat exchanger technology, specifically relating to a support structure for a side tube sheet winding section. Background Technology

[0002] Spiral coil heat exchangers, with their advantages of compact structure, large heat transfer area per unit volume, and self-compensation for thermal expansion of heat exchange tubes, have been widely used in fields such as low-temperature methanol washing, low-temperature air separation, aromatics, and propane dehydrogenation. They also offer advantages such as easy scaling up, reduced equipment quantity, lower energy consumption, and significant energy-saving effects.

[0003] On the shell side of a wound tube heat exchanger, the heat exchange tubes are typically arranged in a multi-layered, staggered winding pattern, with numerous positioning elements distributed between the layers. These positioning elements alter the flow state of the shell-side fluid, leading to a more complex flow field. Under continuous fluid impact, this can easily induce flow-induced vibrations.

[0004] The main factors inducing flow-induced vibrations include:

[0005] Fluid elastic instability: Fluid elastic instability is an important theory in fluid mechanics that describes the vibration phenomenon of tube arrays under crossflow. Its core parameter is the ratio of critical flow velocity to crossflow velocity.

[0006] Karman vortex shedding frequency: the ratio of Karman vortex frequency to the natural frequency of the heat exchange tube;

[0007] Turbulent buffeting: The ratio of the buffeting frequency to the natural frequency of the heat exchange tube; the velocity components in the turbulent fluid in the shell side of the heat exchanger periodically transfer energy to the tube wall. When the frequency of these turbulent components is close to or equal to the natural frequency of the heat exchange tube, the tube wall absorbs energy and resonates, thus causing vibration. This phenomenon is called turbulent buffeting. Summary of the Invention

[0008] The technical problem to be solved by this utility model is to provide a support structure for the lateral tube sheet bypass section in order to reduce the risk of flow-induced vibration, in light of the current state of the technology.

[0009] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: a support structure for a lateral tube sheet bypass section, comprising:

[0010] The shell-side cylindrical body has lateral tube sheets on its side peripheral walls;

[0011] The central cylinder is disposed axially within the shell-side cylinder;

[0012] Multiple heat exchange tubes are arranged axially in the shell-side cylinder and spirally wound around the outer circumference of the central cylinder from the inside to the outside to form a multi-layer spiral tube. Along the axial direction, each layer of spiral tube has a connected spiral section and a winding section. The winding section bends and extends from the end of the spiral section toward the lateral tube sheet and is supported on the lateral tube sheet.

[0013] Its characteristic is that it also includes:

[0014] The first connector is composed of multiple first connecting sleeves, each first connecting sleeve being sleeved on the outer periphery of the winding section of each layer of spiral tube, and the outer wall surfaces of adjacent inner and outer first connecting sleeves are connected so that the first connector as a whole is strip-shaped, and the outer wall surface of the innermost first connecting sleeve is connected to the central cylinder.

[0015] By constraining the outgoing section to the central cylinder with the first connector, the unsupported span of the heat exchange tubes can be reduced, effectively increasing the natural frequency of the heat exchange tubes and thus fundamentally reducing the risk of flow-induced vibration. Furthermore, the design of the first connector, composed of multiple first connecting sleeves, enables precise control of the unsupported span of the outgoing section of the heat exchange tubes.

[0016] Preferably, the mating points of the outer walls of adjacent first connecting sleeves are flat surfaces that fit together. This allows the mating points of the outer walls of adjacent first connecting sleeves to be connected by welding. Furthermore, the design of the flat surfaces prevents excessive spacing between adjacent heat exchange tubes due to the installation of the connecting sleeves.

[0017] Preferably, the two first flat surfaces are partially fitted together and partially offset along their own axial direction.

[0018] Preferably, it also includes a bracket disposed on the outer wall surface of the central cylinder and connected to the outer wall surface of the innermost first connecting sleeve.

[0019] In the above-mentioned schemes, preferably, the connector further includes a second connector composed of a plurality of second connecting sleeves, each second connecting sleeve being respectively sleeved on the outer periphery of the winding section of each layer of spiral tube, and the outer wall surfaces of adjacent inner and outer second connecting sleeves being connected so that the second connector is strip-shaped as a whole, and the second connector and the first connector are arranged at an angle.

[0020] Preferably, the included angle is an acute angle.

[0021] The setting of the included angle has the following effects:

[0022] 1) Impact on the stiffness of heat exchanger tube supports:

[0023] The effects of a large included angle:

[0024] If the angle between the first and second connectors is large (close to perpendicular), their support directions are more complementary, forming a more uniform constraint network. This can significantly improve the overall support stiffness of the heat exchange tubes, reduce flexural deformation in unsupported spans, and thus suppress the risk of displacement caused by fluid impact or vibration.

[0025] The effect of a smaller included angle:

[0026] If the included angle is small, it may lead to insufficient local support stiffness, especially in multi-layer wound tube structures, where support blind spots are likely to occur, increasing the possibility of fatigue damage to the heat exchange tubes due to vibration or thermal expansion.

[0027] 2) Compensation capability for thermal expansion displacement:

[0028] Advantages of a large angle:

[0029] The large included-angle design allows the clamps to provide elastic restraint in different dimensions (horizontal and vertical directions). When the heat exchange tubes expand thermally, the elastic deformation of the connecting sleeve can absorb multi-directional displacement, avoiding stress concentration caused by rigid fixing.

[0030] Limitations of small angles:

[0031] If the included angle is too small, the constraint directions of the first and second connecting parts will tend to be the same, which may restrict the free expansion of the heat exchange tube in a specific direction, resulting in the inability to effectively release thermal stress and increasing the risk of damage to the heat exchange tube.

[0032] 3) Suppression effect of flow-induced vibration:

[0033] Relationship between included angle and natural frequency:

[0034] The included angle directly affects the natural frequency of the heat exchange tube. A large included angle design, through multi-point distributed support, shortens the unsupported span, significantly increases the natural frequency of the heat exchange tube, and keeps it away from the main excitation frequency of flow-induced vibration (such as the Karman vortex street frequency or turbulent chattering frequency), thereby avoiding resonance.

[0035] Dispersion of vibrational energy:

[0036] A well-designed angle can guide the fluid impact energy to disperse in the horizontal and vertical directions, reducing the amplitude of local vibrations.

[0037] 4) Structural adaptability and installation / maintenance:

[0038] Matching the included angle with complex structures:

[0039] In wound tube heat exchangers with multiple layers of spiral tubes, the winding directions of different spiral tube layers may differ. By adjusting the included angle, the arrangement characteristics of each spiral tube layer can be adapted to ensure uniform transmission of support force and avoid localized stress concentration caused by structural mismatch.

[0040] The purpose of choosing an appropriate angle:

[0041] Balancing stiffness and flexibility: While ensuring sufficient support stiffness, a certain elastic deformation capacity is retained through the angle design, achieving dual optimization of thermal expansion displacement and vibration suppression.

[0042] Optimize vibration suppression and heat transfer efficiency:

[0043] To avoid wear or leakage of heat exchange tubes due to vibration, and to maintain uniformity of the flow field through stable support, thereby improving the overall heat transfer efficiency.

[0044] Preferably, the first connector is relatively close to the helical segment, and the second connector is relatively far away from the helical segment.

[0045] Furthermore, the outgoing section has a first section extending radially inward from the lateral tube sheet along the shell-side cylinder, and a second section extending backward from the inner end of the first section toward the helical section, the end of the second section being connected to the end of the helical section;

[0046] The first connector is configured corresponding to the first segment, and the second connector is configured corresponding to the second segment.

[0047] Preferably, the mating point of the outer wall surfaces of adjacent second connecting sleeves is a second flat surface that fits together, with the two second flat surfaces partially fitting together and partially offset along their own axial direction.

[0048] Compared with the prior art, the advantages of this utility model are as follows: by connecting the outgoing sections of adjacent spiral tubes through the first connector, the whole is constrained together with the central cylinder, which can reduce the unsupported span of the heat exchange tubes, effectively increase the natural frequency of the heat exchange tubes, and thus fundamentally reduce the risk of flow-induced vibration. Moreover, the design of the first connector composed of multiple first connecting sleeves can achieve precise control of the unsupported span of the outgoing sections of the heat exchange tubes. Attached Figure Description

[0049] Figure 1 is a structural schematic diagram of the wound tube heater according to an embodiment of the present invention;

[0050] Figure 2 is an enlarged view of part A in Figure 1;

[0051] Figure 3 is a structural schematic diagram of the second connecting sleeve according to an embodiment of the present utility model;

[0052] Figure 4 is a partial structural cross-sectional view of each of the second connecting sleeves in use according to an embodiment of the present invention;

[0053] Figure 5 is a cross-sectional view of the second connecting sleeve according to an embodiment of the present utility model;

[0054] Figure 6 is a schematic diagram of the structure of the first connecting sleeve according to an embodiment of the present invention;

[0055] Figure 7 is a partial structural cross-sectional view of each of the first connecting sleeves in use according to an embodiment of the present invention;

[0056] Figure 8 is a cross-sectional view of the first connecting sleeve according to an embodiment of the present utility model;

[0057] Figure 9 is a partial structural schematic diagram of the central cylinder and support in an embodiment of this utility model;

[0058] Figure 10 is a schematic diagram of the structure along the BB direction in Figure 9;

[0059] Figure 11 is an enlarged view of a partial structure in Figure 1;

[0060] Figure 12 is a top view of Figure 11;

[0061] Figure 13 is an enlarged view of another partial structure in Figure 1;

[0062] Figure 14 is a schematic diagram of the distribution plate according to an embodiment of the present utility model;

[0063] Figure 15 is an enlarged view of another partial structure in Figure 1;

[0064] Figure 16 is a side view of Figure 15;

[0065] Figure 17 is a schematic diagram of the CC-direction structure in Figure 1; Detailed Implementation

[0066] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0067] As shown in Figures 1-17, this is a preferred embodiment of a support structure for a side tube sheet winding section according to the present invention. This support structure is used in a wound tube heat exchanger. This embodiment is described in conjunction with the structure of a wound tube heat exchanger, as follows:

[0068] The wound tube heat exchanger includes a shell-side cylinder 1, heat exchange tubes 2, distribution plate 3, shell-side connecting pipe 4, crossbeam 5, hanger rod 6, central cylinder 7, and connecting parts.

[0069] The shell-side cylinder 1 is vertically arranged, with an upper lateral tube sheet 11 and a lower lateral tube sheet 12 arranged vertically on its side wall, both located on the left side of the shell-side cylinder 1. The shell-side cylinder 1 has a shell-side outlet 13 at the top and a shell-side inlet 14 at the bottom. The aforementioned shell-side connecting pipe 4 is arc-shaped, with its upper port facing upwards and connecting to the shell-side inlet 14, and its lower port facing left, for the shell-side medium to enter.

[0070] The aforementioned distribution plate 3 is circular and horizontally positioned in the lower space of the shell-side cylinder 1, above the shell-side inlet 14 and below the lower side tube sheet 12, dividing the internal space of the shell-side cylinder 1 into upper and lower parts: an upper space 1a with the aforementioned shell-side outlet 13 and a lower space 1b with the aforementioned shell-side inlet 14. The distribution plate 3 has a first part 31 with a plurality of evenly distributed through holes 30 connecting the upper space 1a and the lower space 1b, and a second part 32 without through holes 30. The first part 31 is located on the left side of the distribution plate 3, and the first part 31 and the second part 32 are arranged circumferentially along the distribution plate 3, with the first part 31 occupying a larger proportion of the distribution plate 3 than the second part 32. The diameter and number of the aforementioned through holes 30 are designed according to actual operating conditions to achieve uniform fluid distribution. See Figure 14 for details. Meanwhile, in order to support the distribution plate 3, as shown in Figures 1, 11, and 12, multiple supporting ribs 33 are provided on the lower side of the distribution plate 3. Each supporting rib 33 is arranged at equal intervals along the circumference, and the upper end of each supporting rib 33 supports the distribution plate 3, while the lower end is supported on the bottom of the shell-side cylinder 1 and the periphery of the shell-side inlet 14.

[0071] The aforementioned central cylinder 7 is vertically arranged in the upper space 1a, and the lower end of the central cylinder 7 is supported in the center of the distribution plate 3. The upper end of the central cylinder 7 is supported on the side wall of the shell-side cylinder 1 by a number of circumferentially spaced and radially extended crossbeams 5. Specifically, the inner end of each crossbeam 5 is connected to the side wall of the central cylinder 7, and the outer end of each crossbeam 5 is supported on the flange of the side wall of the shell-side cylinder 1.

[0072] Multiple heat exchange tubes 2 are vertically arranged in the upper space 1a and spirally wound around the outer periphery of the central cylinder 7 from the inside out to form a multi-layer spiral tube 20. Each layer of spiral tube 20 has a spiral section 21 in the middle and winding sections on the upper and lower sides. The ends of the upper winding section 22 and the lower winding section 23 are bent and supported on their respective upper lateral tube sheet 11 and lower lateral tube sheet 12, respectively. The projection of the lower winding section 23 of each spiral tube 20 in the vertical direction falls within the second part 32 of the distribution plate 3. At the same time, in this embodiment, each winding section has a first section 2a extending radially inward from the lateral tube sheet it is located along the shell side cylinder 1, and a second section 2b extending toward the spiral section 21 from the inner end of the first section 2a. The end of the second section 2b is connected to the end of the spiral section 21.

[0073] As shown in Figure 1, there are two sets of connectors, used to connect the upper winding section 22 to the central cylinder 7 and the lower winding section 23 to the central cylinder 7, respectively. Each set of connectors includes a first connector 81 composed of multiple first connecting sleeves 810. Each first connecting sleeve 810 is sleeved on the outer periphery of the winding section on the corresponding side of each layer of spiral tube 20, and the outer walls of adjacent inner and outer first connecting sleeves 810 are connected by welding, making the first connector 81 as a whole strip. The outer wall of the innermost first connecting sleeve 810 is connected to the central cylinder 7 through a bracket 83. The bracket 83 is located on the outer wall of the central cylinder 7 and is connected to the outer wall of the innermost first connecting sleeve 810 by welding. Each set of connectors also includes a second connector 82 composed of multiple second connecting sleeves 820. Each second connecting sleeve 820 is respectively fitted onto the outer periphery of the winding section on the side where the first connecting sleeve 810 is located in each layer of spiral tube 20. The outer walls of adjacent inner and outer second connecting sleeves 820 are connected by welding, making the second connector 82 as a whole strip. The second connector 82 and the first connector 81 are arranged at an acute angle. In this embodiment, the first connector 81 corresponds to the second segment 2b of the winding section, and the second connector 82 corresponds to the first segment 2a of the winding section. The mating point of the outer walls of adjacent first connecting sleeves 810 is a first flat surface that fits together; the two first flat surfaces are partially fitted together and partially offset along their own axial direction. The mating point of the outer walls of adjacent second connecting sleeves 820 is a second flat surface that fits together; the two second flat surfaces are partially fitted together and partially offset along their own axial direction. Please refer to Figures 4 and 7 for details.

[0074] Multiple vertically arranged hanger rods 6 are provided. The upper end of each hanger rod 6 is attached to its corresponding crossbeam 5 and can move along the length of the crossbeam 5 under the action of external force. The lower end of each hanger rod 6 is connected to the spiral section 21, so that the spiral section 21 is suspended below the crossbeam 5 by the hanger rod 6. In this embodiment, as in the prior art, a spacer strip is provided between the inner and outer spiral sections, and the lower end of the hanger rod 6 can be connected to the spacer strip. Please refer to Figures 1, 15, and 16 for details.

[0075] The heat exchanger in this embodiment has the following technical advantages:

[0076] 1) Uniform fluid distribution, avoiding flow deviation and dead zones: The through holes on the first part of the distribution plate can guide the shell-side medium into the shell side and then evenly distribute it to each layer of spiral tubes, ensuring that the shell-side medium and the heat exchange tubes are in full contact, reducing the decrease in heat exchange efficiency caused by uneven local flow.

[0077] 2) Suppressing Flow-Induced Vibration and Fluid Elastic Instability: Adjusting the size and density of the openings on the distribution plate according to actual operating conditions can effectively reduce the crossflow velocity of the shell-side fluid, preventing it from approaching the critical velocity, thereby suppressing flow instability caused by excessively high velocity. Furthermore, the positional relationship between the lower outflow section and the distribution plate reduces the impact of the shell-side medium on the heat exchange tubes, especially the direct impact on the lower outflow section. This guides the high-speed shell-side medium to a low-resistance region, reducing turbulent chattering and Karman vortex shedding frequencies, and preventing resonance with the natural frequency of the heat exchange tubes.

[0078] 3) Reduce the risk of thermal stress and fatigue damage: The perforated arrangement of the distribution plate can guide the stratified mixing of hot and cold media in the tube side and shell side, reduce the local temperature gradient, and reduce thermal stress.

[0079] 4) Improved heat exchange efficiency and energy saving effect: The perforated arrangement on the distribution plate can reduce the flow resistance of the shell-side medium in the shell side, reduce pressure drop loss, achieve smooth flow velocity transition, and reduce energy consumption; and the uniformly distributed flow field maximizes the contact area between the shell-side medium and the heat exchange tube, enhancing the overall heat transfer efficiency.

[0080] 5) Extended equipment lifespan and reliability: This invention reduces the cumulative effect of flow-induced vibration and thermal stress from the source. The distribution plate design prevents the shell-side medium from directly impacting the heat exchange tube bundle, reducing the risk of material fatigue caused by vibration. At the same time, the distribution plate design also improves the heat exchanger's adaptability to extreme operating conditions (such as sudden flow changes), avoiding local overload through dynamic flow field adjustment, and extending the equipment's service life.

[0081] The heat exchanger in this embodiment can be used in an air separation unit, where the shell-side inlet is used to supply waste nitrogen, and the heating steam flows through the tube side.

[0082] In the specification and claims of this utility model, terms indicating direction, such as "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for illustrative purposes and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0083] The term "vertical" is also used in the specification and claims of this utility model, meaning basically along the up and down direction, and is not limited to just the vertical direction, but can also be slightly deviated from the vertical direction.

[0084] The term "radial" is also used in the specification and claims of this utility model, meaning basically along the inside and outside direction, and is not limited to the radial direction that passes through the center of the circle, but can also be slightly deviated from the radial direction.

Claims

1. A support structure for a lateral tube sheet winding section, comprising: a shell-side cylinder (1) having a lateral tube sheet on its sidewall; a central cylinder (7) axially disposed within the shell-side cylinder (1); and multiple heat exchange tubes (2) axially disposed within the shell-side cylinder (1), spirally wound from the inside out around the central cylinder (7) to form a multi-layered spiral tube (20), wherein each layer of spiral tube (20) has a connected spiral section (21) and a winding section, the winding section extending from the end of the spiral section (21) toward the lateral tube sheet and supported on the lateral tube sheet; characterized in that It also includes: a first connector (81) composed of multiple first connecting sleeves (810), each first connecting sleeve (810) being sleeved on the outer periphery of the winding section of each layer of spiral tube (20), and the outer wall surfaces of adjacent first connecting sleeves (810) being connected so that the first connector (81) is strip-shaped as a whole, and the outer wall surface of the innermost first connecting sleeve (810) is connected to the central cylinder (7).

2. The support structure according to claim 1, characterized in that: The mating point of the outer wall surfaces of adjacent first connecting sleeves (810) is a first flat surface that fits together.

3. The support structure according to claim 2, characterized in that: The two first flat surfaces are partially aligned and partially offset along their own axes.

4. The support structure according to claim 1, characterized in that: It also includes a bracket (83) disposed on the outer wall of the central cylinder (7) and connected to the outer wall of the innermost first connecting sleeve (810).

5. The support structure according to any one of claims 1 to 4, characterized in that: It also includes a second connector (82) composed of multiple second connecting sleeves (820), each second connecting sleeve (820) being sleeved on the outer periphery of the winding section of each layer of spiral tube (20), and the outer wall surfaces of adjacent inner and outer second connecting sleeves (820) being connected so that the second connector (82) is strip-shaped as a whole, and the second connector (82) and the first connector (81) are arranged at an angle.

6. The support structure according to claim 5, characterized in that: The included angle is an acute angle.

7. The support structure according to claim 5, characterized in that: The first connector (81) is relatively close to the helical segment (21), and the second connector (82) is relatively far away from the helical segment (21).

8. The support structure according to claim 7, characterized in that: The winding section has a first section (2a) extending radially inward from the lateral tube sheet along the shell-side cylinder (1), and a second section (2b) extending backward from the inner end of the first section (2a) toward the helical section (21), the end of the second section (2b) being connected to the end of the helical section (21); the first connector (81) is provided corresponding to the first section (2a), and the second connector (82) is provided corresponding to the second section (2b).

9. The support structure according to claim 5, characterized in that: The mating point of the outer wall surfaces of adjacent second connecting sleeves (820) is a second flat surface that fits together. The two second flat surfaces are partially fitted together and partially offset along their own axial direction.

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