Shell-and-tube heat exchanger and refrigeration equipment
By using a serpentine heat exchanger tube bundle structure and radial limiting support design, the problems of low heat transfer efficiency and thermal stress in shell-and-tube heat exchangers under conditions of large flow rate and temperature difference are solved, achieving efficient heat transfer and simple structural design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-03-31
AI Technical Summary
Existing shell-and-tube heat exchangers have low heat transfer efficiency when the flow rates of the two materials differ significantly, and are prone to generating thermal stress, making it difficult to meet usage requirements.
The system employs a serpentine heat exchange tube bundle structure, where the fluid with a larger flow rate flows on the outside and the fluid with a smaller flow rate flows on the inside. The serpentine flow channel is formed by the bends in the tubes and is supported radially to avoid axial fixation, thereby reducing fluid stagnation layers and thermal stress.
It improves heat transfer efficiency, reduces fluid temperature gradient and thermal stress, simplifies structural design, and reduces material consumption and manufacturing costs.
Smart Images
Figure CN121761664A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of air conditioning and refrigeration technology, specifically, it relates to a shell-and-tube heat exchanger and refrigeration equipment. Background Technology
[0002] A typical shell-and-tube heat exchanger is a tubular heat exchanger with two fixed tube sheets, or one fixed tube sheet and one movable tube sheet. Generally, typical shell-and-tube heat exchangers can be divided into multi-shell-pass or multi-tube-pass types. Increasing the number of shell or tube passes increases the fluid velocity, thereby improving the heat transfer efficiency. Although typical shell-and-tube heat exchangers are also suitable for heat transfer between two materials with significantly different flow rates, their structure is more dispersed, their volume is larger, and they consume more material.
[0003] In many processes, shell-and-tube heat exchangers are used for heat exchange between two materials. When the flow rates of the two materials differ significantly, even if the material with the lower flow rate flows through the tubes and the number of tubes is increased, it is difficult to increase its velocity. This results in a very low flow velocity, causing the material to flow in a stagnant state. Consequently, the heat transfer film coefficient of the material is very low, leading to low heat transfer efficiency of the heat exchanger and preventing it from performing its normal heat transfer performance. Furthermore, when there is a large temperature difference between the two materials, significant thermal stress will be generated in the tube and shell sides, making it difficult for ordinary shell-and-tube or double-tube heat exchangers to meet the application requirements. Summary of the Invention
[0004] In view of the problem that the heat exchanger has low heat transfer efficiency when the flow rate difference between two materials is large during heat exchange, this application provides a shell-and-tube heat exchanger and a refrigeration device to improve the heat exchange efficiency when the flow rate difference between two materials is large.
[0005] In a first aspect, this application provides a shell-and-tube heat exchanger, including a first tube box, a second tube box and a cylinder. The first tube box and the second tube box are respectively sealed and fixed at both ends of the cylinder to form a heat exchange space. A heat exchange tube bundle is provided in the heat exchange space. The first tube box is provided with a first tube opening, the second tube box is provided with a second tube opening, and the cylinder is provided with a first tube bundle opening and a second tube bundle opening. The heat exchange tube bundle includes a plurality of parallel heat exchange tubes and a bend connecting the beginning and end of the plurality of heat exchange tubes. One end of the heat exchange tube is connected to the opening of the first tube bundle, and the other end is connected to the opening of the second tube bundle. The cylinder body is provided with several heat exchange tube supports along the axial direction to limit the radial movement of the heat exchange tubes, and a fixed-distance tube is fixedly connected between adjacent heat exchange tube supports.
[0006] In one possible embodiment, the first port and the second port are radially opposite to each other on the first pipe box and the second pipe box, respectively.
[0007] In one possible embodiment, the heat exchange tube support includes a support ring fixed to the inner wall of the cylinder. The support ring has a plurality of first support rods distributed parallel to a first direction and a plurality of second support rods distributed parallel to a second direction. A diamond-shaped through hole is formed between the plurality of first support rods and the plurality of second support rods to allow the heat exchange tube to pass through and to restrict the radial movement of the heat exchange tube.
[0008] In one possible embodiment, the first direction is perpendicular to the second direction.
[0009] In one possible embodiment, the two end faces of the cylinder are respectively provided with a first tube sheet and a second tube sheet, the heat exchange tube support is a circular plate that matches the inner wall of the cylinder, and the first tube sheet, the second tube sheet and the heat exchange tube support are provided with a plurality of through holes that limit the radial movement of the heat exchange tube.
[0010] In one possible embodiment, the first tube sheet, the second tube sheet, and the heat exchange tube support are all provided with vent holes and / or liquid passage holes.
[0011] In one possible embodiment, when the shell-and-tube heat exchanger is placed horizontally, the first tube sheet, the second tube sheet, and the heat exchange tube support are all provided with radially opposite vent holes and liquid passage holes, wherein the vent holes are located directly above and the liquid passage holes are located directly below.
[0012] In one possible embodiment, at least one tie rod is also included, with one end of each tie rod fixed to the first tube sheet or the second tube sheet, and the other end passing through a tie rod hole on the spacer tube and the heat exchange tube support for fixation.
[0013] In one possible embodiment, the connection point between the heat exchange tube and the bend is located within the maintenance space enclosed by the two end faces of the cylinder and the first tube box and the second tube box, respectively.
[0014] Secondly, this application also provides a refrigeration device, including the shell-and-tube heat exchanger described in any embodiment of the first aspect.
[0015] This application provides a shell-and-tube heat exchanger and a refrigeration device. The shell-and-tube heat exchanger includes a first tube box, a second tube box, and a cylinder. The first tube box and the second tube box are respectively sealed and fixed at both ends of the cylinder to form a heat exchange space. A heat exchange tube bundle is provided in the heat exchange space. The heat exchange tube bundle includes a plurality of parallel heat exchange tubes and a bend connecting the beginning and end of the plurality of heat exchange tubes. A plurality of heat exchange tube supports are provided in the axial direction of the cylinder to limit the radial movement of the heat exchange tubes. A spacer tube is fixedly connected between adjacent heat exchange tube supports. Therefore, the heat exchange tubes and the bend tubes form an internal serpentine tube.
[0016] Because the heat exchange tube bundle in this application forms a serpentine tube, when a larger flow rate fluid flows from outside the heat exchange tube bundle while a smaller flow rate fluid flows from inside, the fluid inside the serpentine tube experiences a sudden change in flow direction when encountering bends. This redistribution of the fluid across the cross-section helps reduce the stagnant layer, thereby reducing the temperature gradient across the cross-section and increasing heat transfer efficiency. In contrast, for shell-and-tube heat exchangers, when the fluid inside the tubes veers back through the tube boxes at both ends, the sudden expansion and contraction of the flow channels increases flow resistance. Furthermore, if there is a phase change in the fluid inside the tubes, gas and liquid phase separation occurs at the tube box due to velocity changes in multiple tube passes (whether straight or U-shaped), significantly altering the flow state within the tube passes. This results in uneven velocity and phase distribution within the heat exchange tubes, leading to a decrease in heat transfer efficiency. In contrast, the fluid velocity inside the heat exchange tubes of this application is essentially uniform, and the phase distribution is homogeneous, resulting in significantly lower flow resistance and improved heat transfer efficiency.
[0017] Furthermore, when the fluid inside the coil exchanges heat with the fluid outside the coil through the coil wall, the flow rate outside the coil is larger, resulting in a smaller temperature difference between its inlet and outlet, while the flow rate inside the coil is smaller, resulting in a larger temperature difference between its inlet and outlet. This temperature difference causes the coil to shift axially in the heat exchange tube. Since the heat exchange tube is only limited to radial movement and not fixed in the axial direction, each heat exchange tube can move axially under the influence of the temperature difference without generating additional stress. This design can adapt to situations where the temperature difference between the two fluids is large. Moreover, since there is no additional stress, this design does not require complex stress calculations, making the design simpler. Attached Figure Description
[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0019] Figure 1 A schematic diagram of a shell-and-tube heat exchanger provided in an embodiment of this application; Figure 2 This is a schematic diagram of the cross-sectional structure of the heat exchanger tube bundle; Figure 3 for Figure 1 A three-dimensional structural schematic diagram of the heat exchanger tube support in the embodiment shown; Figure 4 A front view schematic diagram of the structure supporting the heat exchange tubes; Figure 5 This is a schematic diagram of the assembly structure between the heat exchanger tube and the heat exchanger tube support. Figure 6 This is a schematic diagram of the structure of a shell-and-tube heat exchanger provided in another embodiment of this application; Figure 7 for Figure 6A schematic diagram of the heat exchanger tube support structure in the embodiment shown.
[0020] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments.
[0021] Explanation of reference numerals in the attached figures: 10-First pipe box, 11-First pipe opening, 20-Second pipe box, 21-Second pipe opening; 30-Cylinder body, 31-First tube bundle inlet, 32-Second tube bundle inlet, 33-First tube sheet, 34-Second tube sheet; 40-Heat exchange tube bundle, 41-Heat exchange tube, 42-Bend tube, 43-Heat exchange tube support, 431-Support ring, 432-First support rod, 433-Second support rod, 434-Rhomboid through hole, 435-Through hole, 436-Vent hole, 437-Liquid passage hole, 44-Spacing tube, 45-Tie rod, 46-Locking nut. Detailed Implementation
[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0023] In the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" do not necessarily imply that they are different.
[0024] It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner. In the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more.
[0025] It should be noted that "at the time of..." in the embodiments of this application can be either at the instant when a certain situation occurs, or for a period of time after the occurrence of a certain situation. The embodiments of this application do not make specific limitations on this.
[0026] In many processes, shell-and-tube heat exchangers are used for heat exchange between two materials. When the flow rates of the two materials differ significantly, even if the material with the lower flow rate flows through the tubes and the number of tubes is increased, it is difficult to increase its velocity. This results in a very low flow velocity, causing the material to stagnate and its heat transfer coefficient to be very low. Consequently, the heat exchanger's heat transfer efficiency is low, and it cannot perform its normal heat transfer performance. Furthermore, when there is a large temperature difference between the two materials, significant thermal stress will be generated in the tube and shell sides, making it difficult for ordinary shell-and-tube or double-tube heat exchangers to meet the requirements.
[0027] In order to solve the above-mentioned problems in the prior art, this application provides a shell-and-tube heat exchanger and a refrigeration device. The heat exchanger contains a heat exchange tube bundle that forms a serpentine structure by means of several parallel heat exchange tubes and a bend connecting the beginning and end of several heat exchange tubes. At the same time, several heat exchange tube supports are provided in the axial direction of the heat exchange tubes to limit the radial movement of the heat exchange tubes, while the axial direction of the heat exchange tubes is not fixed. In this scenario, when a larger flow rate fluid flows from outside the heat exchange tube bundle, while a smaller flow rate fluid flows from inside, the fluid inside the coil experiences a sudden change in flow direction when encountering bends. This redistribution of the fluid across the cross-section helps reduce the stagnant layer, thereby decreasing the temperature gradient across the cross-section and increasing heat transfer efficiency. Furthermore, when the fluid inside the coil exchanges heat with the fluid outside the coil through the tube wall, the larger flow rate outside results in a smaller temperature difference between its inlet and outlet, while the smaller flow rate inside the coil results in a larger temperature difference. This temperature difference causes the coil to shift axially. Since the heat exchange tubes are only limited to radial movement and not fixed axially, each heat exchange tube can move axially under the influence of the temperature difference without generating additional stress. This allows the coil to adapt to situations with a large temperature difference between the two fluids.
[0028] Figure 1 This is a schematic diagram of a shell-and-tube heat exchanger provided in one embodiment of this application. Figure 1 As shown, this embodiment provides a horizontally arranged shell-and-tube heat exchanger, including a first tube box 10, a second tube box 20 and a cylinder 30. The first tube box 10 and the second tube box 20 are respectively sealed and fixed at both ends of the cylinder 30, thereby forming a heat exchange space. The heat exchange space is provided with a heat exchange tube bundle 40 for exchanging heat between the inside and outside.
[0029] Specifically, the two ends of the cylinder 30 are bolted to the first pipe box 10 and the second pipe box 20 through flanges, and sealed with gaskets.
[0030] The first pipe box 10 is provided with a first pipe opening 11, and the second pipe box 20 is provided with a second pipe opening 21. Preferably, the first pipe opening 11 and the second pipe opening 21 are radially opposite to each other on the first pipe box 10 and the second pipe box 20, respectively. In a specific embodiment, the first pipe opening 11 is located directly above the first pipe box 10, and the second pipe opening 21 is located directly below the second pipe box 20.
[0031] The cylinder 30 is provided with a first tube bundle port 31 and a second tube bundle port 32. In a specific embodiment, the first tube bundle port 31 is located at the lower left of the cylinder 30, and the second tube bundle port 32 is located at the upper right of the cylinder 30.
[0032] The heat exchange tube bundle 40 includes a plurality of parallel heat exchange tubes 41 and a bend 42 connecting the beginning and end of the plurality of heat exchange tubes 41. One end of each heat exchange tube 41 is connected to the inlet 31 of the first tube bundle, and the other end is connected to the inlet 32 of the second tube bundle. Therefore, the plurality of heat exchange tubes 41 and the bend 42 connecting the beginning and end of the heat exchange tubes 41 form a serpentine structure in the heat exchange tube bundle 40.
[0033] Figure 2 This is a schematic diagram of the cross-sectional structure of the heat exchanger tube bundle. (Example:) Figure 2 As shown, several parallel heat exchange tubes 41 constitute a multi-layer serpentine tube structure. Seven layers of serpentine tubes are shown, and the flow direction is as follows: after entering from the second port 21, the flow first passes through the inlet of the first layer of serpentine tubes, then flows out from the outlet of the first layer to the inlet of the second layer, then flows out from the outlet of the second layer to the outlet of the third layer, and so on, finally flowing out from the outlet of the seventh layer to the first port 11. It should be noted that for the cylinder 30, the closer to the middle layer of the serpentine tubes, the more heat exchange tubes 41 are required to connect end to end. If the cylinder 30 becomes a pipe structure with a square cross-section, then each layer can use the same number of heat exchange tubes 41 forming a serpentine tube structure.
[0034] The cylinder 30 has several heat exchange tube supports 43 along its axial direction to limit the radial movement of the heat exchange tubes 41, and spacer tubes 44 are fixedly connected between adjacent heat exchange tube supports 43. The heat exchange tube supports 43 can not only prevent the heat exchange tubes 41 from moving radially, but also bear the weight of the heat exchange tubes 41.
[0035] Figure 3 for Figure 1 The schematic diagram of the three-dimensional structure of the heat exchanger tube support in the embodiment shown is as follows. Figure 4 This is a front view schematic diagram of the heat exchanger tube support structure. (See attached diagram.) Figure 3 and Figure 4 As shown, the heat exchange tube support 43 provided in this embodiment adopts the following structure: The heat exchange tube support 43 includes a support ring 431 fixed to the inner wall of the cylinder 30. The support ring 431 is provided with a plurality of first support rods 432 distributed in parallel along a first direction and a plurality of second support rods 433 distributed in parallel along a second direction. A diamond-shaped through hole 434 is formed between the plurality of first support rods 432 and the plurality of second support rods 433 to allow the heat exchange tube 41 to pass through and to restrict the radial movement of the heat exchange tube 41.
[0036] Preferably, a plurality of first support rods 432 are distributed in parallel at a distance a, and a plurality of second support rods 433 are also distributed in parallel at a distance a, forming a fixed included angle α between the first direction and the second direction. Therefore, from the cross-section of the cylinder 30, the gap between the plurality of first support rods 432 and the plurality of second support rods 433 forms a rhomboid through hole 434 of the same size with one of its angles being α.
[0037] Preferably, in this embodiment, the heat exchange tube supports 43 are distributed in four groups at equal intervals. After the adjacent heat exchange tube supports 43 are fixed by the spacer tubes 44, it can be ensured that the heat exchange tube supports 43 as a whole will not move relative to each other.
[0038] Figure 5 This is a schematic diagram of the assembly structure between the heat exchanger tubes and their supports. Figure 5 As shown, the four sides of the rhomboid through-hole 434 are exactly tangent to the outer circle of the heat exchange tube 41, thereby restricting the radial movement of the heat exchange tube 41. The gap occupied by the heat exchange tube 41 outside the flow section of the rhomboid through-hole 434 forms a channel for the flow of the same medium with the first pipe opening 11 to the second pipe opening 21.
[0039] More preferably, the first direction and the second direction are perpendicular to each other, that is, the included angle α is fixed at 90 degrees, and the rhomboid through hole 434 is a square through hole.
[0040] Continue reading Figure 1 In this embodiment, the connection between the heat exchange tube 41 and the bend 42 is fixed by welding. The weld is located within the maintenance space enclosed by the two end faces of the cylinder 30 and the first tube box 10 and the second tube box 20, respectively. That is, the weld is located outside the two end faces of the cylinder 30. In this way, when a leak occurs at the weld, the first tube box 10 or the second tube box 20 can be removed first, and the weld can be repaired or the bend 42 replaced directly. If a leak occurs in the heat exchange tube 41, the first tube box 10 or the second tube box 20 can also be removed first. After cutting off the bends 42 at the corresponding ends of the heat exchange tube 41, the heat exchange tube 41 can be pulled out for replacement. Then, the bends 42 and the replaced heat exchange tube 41 can be re-welded and fixed.
[0041] Preferably, the distance between the weld position of the left bend 42 and the left end face of the cylinder 30 and the distance between the weld position of the right bend 42 and the right end face of the cylinder 30 are not less than 50mm, which can increase the maintenance space at the weld position.
[0042] The following is a detailed description. Figure 1 The working principle of the shell-and-tube heat exchanger embodiment shown is as follows: In this embodiment, the shell-and-tube heat exchanger is limited to horizontal installation. The fluid with a large flow rate flows through the cavity outside the heat exchange tube bundle 40. That is, the fluid with a large flow rate either enters from the first port 11 and flows out from the second port 21, or enters from the second port 21 and flows out from the first port 11.
[0043] When the fluid is gaseous, it enters through the upper first port 11, flows through the first tube box 10, the cylinder 30, and the second tube box 20, and exits through the second port 21. When the fluid is liquid, it enters through the lower second port 21, flows through the second tube box 20, the cylinder 30, and the first tube box 10, and exits through the first port 11. During the flow, the fluid is in full contact with the tube wall of the heat exchange tube bundle 40, and the heat exchange tube support 43 disturbs the fluid as it flows through the heat exchange tube bundle 40, thereby increasing the heat transfer efficiency.
[0044] The fluid with a smaller flow rate flows through the serpentine cavity inside the heat exchange tube bundle 40. The fluid enters from the first tube bundle port 31 or the second tube bundle port 32. During the flow process in the serpentine cavity, the flow direction of the fluid with a smaller flow rate will suddenly change when it encounters the bend 42. The fluid is redistributed on the cross-section, which helps to reduce the stagnant layer of the fluid, reduces the temperature gradient of the fluid on the cross-section, and increases the heat transfer rate.
[0045] Because the fluid flow rate outside the heat exchange tube bundle 40 is relatively large, the temperature difference between its inlet and outlet is relatively small, while the fluid flow rate inside the heat exchange tube bundle 40 is relatively small, and the temperature difference between its inlet and outlet is relatively large. Therefore, the heat exchange tube 41 will be displaced along its axial direction due to the large temperature difference. Since the heat exchange tube 41 is only limited to radial movement and is not fixed in the axial direction, each heat exchange tube 41 can move along its axial direction without generating additional stress due to the large temperature difference.
[0046] Figure 6 This is a schematic diagram of a shell-and-tube heat exchanger provided in another embodiment of this application. Figure 6 As shown, this embodiment provides a shell-and-tube heat exchanger, including a first tube box 10, a second tube box 20 and a cylinder 30. The first tube box 10 and the second tube box 20 are respectively sealed and fixed at both ends of the cylinder 30, thereby forming a heat exchange space. The heat exchange space is provided with a heat exchange tube bundle 40 for exchanging heat between the inside and outside.
[0047] Specifically, the two ends of the cylinder 30 are bolted to the first pipe box 10 and the second pipe box 20 through flanges, and sealed with gaskets.
[0048] The first pipe box 10 is provided with a first pipe opening 11, and the second pipe box 20 is provided with a second pipe opening 21. Preferably, the first pipe opening 11 and the second pipe opening 21 are radially opposite to each other on the first pipe box 10 and the second pipe box 20, respectively. In a specific embodiment, the first pipe opening 11 is located directly above the first pipe box 10, and the second pipe opening 21 is located directly below the second pipe box 20.
[0049] The cylinder 30 is provided with a first tube bundle port 31 and a second tube bundle port 32. In a specific embodiment, the first tube bundle port 31 is located at the lower left of the cylinder 30, and the second tube bundle port 32 is located at the upper right of the cylinder 30.
[0050] The heat exchange tube bundle 40 includes a plurality of parallel heat exchange tubes 41 and a bend 42 connecting the beginning and end of the plurality of heat exchange tubes 41. One end of each heat exchange tube 41 is connected to the inlet 31 of the first tube bundle, and the other end is connected to the inlet 32 of the second tube bundle. Therefore, the plurality of heat exchange tubes 41 and the bend 42 connecting the beginning and end of the heat exchange tubes 41 form a serpentine structure in the heat exchange tube bundle 40.
[0051] For the specific structure of the heat exchanger tube bundle 40, please refer to Figure 2 The corresponding descriptions will not be repeated here.
[0052] The cylinder 30 has several heat exchange tube supports 43 along its axial direction to limit the radial movement of the heat exchange tubes 41, and spacer tubes 44 are fixedly connected between adjacent heat exchange tube supports 43. The heat exchange tube supports 43 can not only prevent the heat exchange tubes 41 from moving radially, but also bear the weight of the heat exchange tubes 41.
[0053] Figure 7 for Figure 6 A schematic diagram of the heat exchanger tube support 43 in the illustrated embodiment. Figure 7 As shown, this embodiment is similar to Figure 1 The difference of the shell-and-tube heat exchanger shown is that: the two ends of the shell 30 are respectively provided with a first tube sheet 33 and a second tube sheet 34, the heat exchange tube support 43 is a circular plate that matches the inner wall of the shell 30, and the first tube sheet 33, the second tube sheet 34 and the heat exchange tube support 43 are provided with a number of through holes 435 that limit the radial movement of the heat exchange tube 41.
[0054] In the above embodiments, the heat exchange tube support 43 is no longer used. Figure 3 and Figure 4 Instead of the structure shown, it adopts Figure 7 The heat exchange tube support 43 structure shown means that the heat exchange tube 41 in this embodiment must not only pass through the through hole 435 on the circular plate, but also through the through hole 435 on the first tube plate 33 and the second tube plate 34 at both ends of the cylinder 30.
[0055] Since the through holes 435 on the first tube sheet 33, the second tube sheet 34 and the heat exchange tube support 43 need to limit the radial movement of the heat exchange tube 41, the size of the through holes 435 needs to match the size of the heat exchange tube 41. At this time, the large flow of fluid entering from the first port 11 or the second port 21 can no longer pass through the gap at the diamond-shaped through hole 434 and flow out from the other end.
[0056] Therefore, based on the above problems, this application requires that vent holes 436 and / or liquid passage holes 437 be provided on the first tube sheet 33, the second tube sheet 34 and the heat exchange tube support 43.
[0057] When the shell-and-tube heat exchanger is placed horizontally, the first tube sheet 33, the second tube sheet 34, and the heat exchange tube support 43 are all provided with radially opposite vent holes 436 and liquid passage holes 437. The vent holes 436 are preferably located directly above the first tube sheet 33, the second tube sheet 34, and the heat exchange tube support 43, while the liquid passage holes 437 are preferably located directly below the first tube sheet 33, the second tube sheet 34, and the heat exchange tube support 43. This allows gas to flow through the vent holes 436 directly above when gas enters from the first port 11, and allows gas to flow through the liquid passage holes 437 directly below when liquid enters from the second port 21.
[0058] Since the first tube sheet 33 and the second tube sheet 34 provide support, only two sets of heat exchange tube supports 43 (i.e., circular plates) are required in this embodiment. To ensure that the relative positions of the two sets of heat exchange tube supports 43 with the first tube sheet 33 and the second tube sheet 34 do not change, a tie rod 45 is provided at the upper and lower ends of the cylinder 30 in this embodiment. One end of each tie rod 45 is fixed to the first tube sheet 33 or the second tube sheet 34 (in this embodiment, both the upper and lower tie rods 45 are fixed to the first tube sheet 33 on the left side), and the other end passes through the spacer tube 44 between the first tube sheet 33 and the first heat exchange tube support 43, the tie rod 45 hole on the first heat exchange tube support 43, the spacer tube 44 between the first heat exchange tube support 43 and the second heat exchange tube support 43, and the tie rod 45 hole on the second heat exchange tube support 43 before being fixed. For example, the tie rod 45 can be fixed by locking the tie rod 45 through the tie rod 45 hole on the second heat exchange tube support 43.
[0059] Continue reading Figure 6In this embodiment, the connection between the heat exchange tube 41 and the bend 42 is fixed by welding. The weld is located within the maintenance space enclosed by the first tube sheet 33 and the first tube box 10, and the second tube sheet 34 and the second tube box 20, respectively. That is, the weld is located outside the two end faces of the cylinder 30. In this way, when a leak occurs at the weld, the first tube box 10 or the second tube box 20 can be removed first, and the weld can be repaired or the bend 42 replaced directly. If a leak occurs in the heat exchange tube 41, the first tube box 10 or the second tube box 20 can also be removed first. After cutting off the bends 42 at the corresponding ends of the heat exchange tube 41, the heat exchange tube 41 can be pulled out for replacement. Then, the bends 42 and the replaced heat exchange tube 41 can be re-welded and fixed.
[0060] Preferably, the distance between the weld position of the left bend 42 and the first tube sheet 33 and the distance between the weld position of the right bend 42 and the second tube sheet 34 are not less than 50mm. This not only increases the maintenance space at the weld position, but also provides the axial movement distance of the heat exchange tube 41 due to the temperature difference.
[0061] The following is a detailed description. Figure 6 The working principle of the shell-and-tube heat exchanger embodiment shown is as follows: In this embodiment, the shell-and-tube heat exchanger can be installed horizontally or vertically. The fluid with a large flow rate flows through the cavity outside the heat exchange tube bundle 40. That is, the fluid with a large flow rate either enters from the first port 11 and flows out from the second port 21, or enters from the second port 21 and flows out from the first port 11.
[0062] When installed horizontally, the gaseous fluid enters from the upper first port 11, flows through the first tube box 10, the vent 436, and the second tube box 20, and exits from the second port 21; the liquid fluid enters from the lower second port 21, flows through the second tube box 20, the liquid passage 437, and the first tube box 10, and exits from the first port 11. During the flow, the fluid makes full contact with the tube wall of the heat exchange tube bundle 40, and the heat exchange tube support 43 disturbs the fluid as it flows through the heat exchange tube bundle 40, thereby increasing the heat transfer efficiency.
[0063] When installed vertically, the flow direction of the high-flow-rate fluid outside the heat exchange tube 41 is set in the manner of gas entering from the top and exiting from the bottom, and liquid entering from the bottom and exiting from the top.
[0064] The fluid with a smaller flow rate flows through the serpentine cavity inside the heat exchange tube bundle 40. The fluid enters from the first tube bundle port 31 or the second tube bundle port 32. During the flow process in the serpentine cavity, the flow direction of the fluid with a smaller flow rate will suddenly change when it encounters the bend 42. The fluid is redistributed on the cross-section, which helps to reduce the stagnant layer of the fluid, reduces the temperature gradient of the fluid on the cross-section, and increases the heat transfer rate.
[0065] Because the fluid flow rate outside the heat exchange tube bundle 40 is relatively large, the temperature difference between its inlet and outlet is relatively small, while the fluid flow rate inside the heat exchange tube bundle 40 is relatively small, and the temperature difference between its inlet and outlet is relatively large. Therefore, the heat exchange tube 41 will be displaced along its axial direction due to the large temperature difference. Since the heat exchange tube 41 is only limited to radial movement and is not fixed in the axial direction, each heat exchange tube 41 can move along its axial direction without generating additional stress due to the large temperature difference.
[0066] The shell-and-tube heat exchanger using any of the above embodiments is suitable for heat transfer applications where the flow rates of the two fluids differ significantly. Secondly, compared to ordinary shell-and-tube heat exchangers, the heat exchange tubes 41 are arranged more compactly, resulting in higher space utilization, a smaller heat exchanger volume, and less material consumption. Furthermore, when the temperature difference between the two fluids is large, it can also avoid large thermal stress between the heat exchange tubes 41 and the shell 30, making it suitable for applications with large temperature differences between the two fluids. Since the shell-and-tube heat exchanger of this application does not have additional stress caused by temperature differences, complex tube sheet stress calculations are not required, simplifying the structural design. In a second aspect, this application also provides a refrigeration device, including the shell-and-tube heat exchanger described in any of the foregoing embodiments. The refrigeration device using this heat exchanger can provide a solution for heat transfer of fluids with large flow rate or temperature differences, and its structural design is simpler, reducing manufacturing costs.
[0067] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A shell-and-tube heat exchanger, comprising a first tube box (10), a second tube box (20), and a shell (30), wherein the first tube box (10) and the second tube box (20) are respectively sealed and fixed at both ends of the shell (30) to form a heat exchange space, wherein a heat exchange tube bundle (40) is provided in the heat exchange space, wherein the first tube box (10) is provided with a first tube opening (11), the second tube box (20) is provided with a second tube opening (21), and the shell (30) is provided with a first tube bundle opening (31) and a second tube bundle opening (32), characterized in that: The heat exchange tube bundle (40) includes a plurality of parallel heat exchange tubes (41) and a bend (42) connecting the beginning and end of the plurality of heat exchange tubes (41). One end of the heat exchange tube (41) is connected to the first tube bundle port (31), and the other end is connected to the second tube bundle port (32). The cylinder (30) is provided with a plurality of heat exchange tube supports (43) in the axial direction that limit the radial movement of the heat exchange tubes (41), and a fixed distance tube (44) is fixedly connected between adjacent heat exchange tube supports (43).
2. The shell-and-tube heat exchanger according to claim 1, characterized in that, The first port (11) and the second port (21) are radially opposite to each other on the first pipe box (10) and the second pipe box (20), respectively.
3. The shell-and-tube heat exchanger according to claim 1 or 2, characterized in that, The heat exchange tube support (43) includes a support ring (431) fixed to the inner wall of the cylinder (30). The support ring (431) is provided with a plurality of first support rods (432) distributed in parallel along a first direction and a plurality of second support rods (433) distributed in parallel along a second direction. A diamond-shaped through hole (434) is formed between the plurality of first support rods (432) and the plurality of second support rods (433) for the heat exchange tube (41) to pass through and for restricting the radial movement of the heat exchange tube (41).
4. The shell-and-tube heat exchanger according to claim 3, characterized in that, The first direction and the second direction are perpendicular to each other.
5. The shell-and-tube heat exchanger according to claim 2, characterized in that, The cylinder (30) has a first tube sheet (33) and a second tube sheet (34) on both ends. The heat exchange tube support (43) is a circular plate that matches the inner wall of the cylinder (30). The first tube sheet (33), the second tube sheet (34) and the heat exchange tube support (43) are provided with a plurality of through holes (435) that limit the radial movement of the heat exchange tube (41).
6. The shell-and-tube heat exchanger according to claim 5, characterized in that, Ventilation holes (436) and / or liquid passage holes (437) are provided on the first tube sheet (33), the second tube sheet (34) and the heat exchange tube support (43).
7. The shell-and-tube heat exchanger according to claim 6, characterized in that, When the shell-and-tube heat exchanger is placed horizontally, the first tube sheet (33), the second tube sheet (34), and the heat exchange tube support (43) are all provided with radially opposite vent holes (436) and liquid passage holes (437), wherein the vent holes (436) are located directly above and the liquid passage holes (437) are located directly below.
8. The shell-and-tube heat exchanger according to any one of claims 5 to 7, characterized in that, It also includes at least one tie rod (45), one end of each tie rod (45) is fixed on the first tube sheet (33) or the second tube sheet (34), and the other end is fixed by passing through the tie rod (45) hole on the spacer tube (44) and the heat exchange tube support (43).
9. The shell-and-tube heat exchanger according to claim 1, characterized in that, The connection point between the heat exchange tube (41) and the bend (42) is located within the maintenance space enclosed by the two end faces of the cylinder (30), the first tube box (10), and the second tube box (20).
10. A refrigeration device, characterized in that, Includes the shell-and-tube heat exchanger as described in any one of claims 1-9.