A spiral flow guide tube heat exchanger

Abstract

This utility model discloses a spiral flow-guided coiled tube heat exchanger, relating to the field of coiled tube heat exchangers. The spiral flow-guided coiled tube heat exchanger includes a heat exchange component and a flow-guided component. The heat exchange component includes a longitudinally penetrating shell and a central cylinder located inside the shell. Multiple layers of heat exchange tubes are arranged around the outer periphery of the central cylinder, and the multiple layers of heat exchange tubes are arranged at intervals along the radial direction of the shell. The flow-guided component includes a flow-guided band, which is spirally arranged around the central cylinder. A flow-guided band is provided between two adjacent layers of heat exchange tubes and between the innermost heat exchange tube and the central cylinder. By setting multiple flow-guided bands, this application transforms the shell-side fluid from the traditional axial flow to spiral turbulence, significantly improving the convective heat transfer coefficient, enhancing the overall heat transfer performance, and guiding the shell-side fluid to form a self-cleaning flow field, reducing dead zones and lowering the risk of scale, impurities, and other deposits accumulating on the tube walls and inside the shell.

Description

Technical Field

[0001] This utility model relates to the field of wound tube heat exchangers, specifically to a spiral flow wound tube heat exchanger. Background Technology

[0002] The coiled tube heat exchanger is a highly efficient and compact heat exchange device widely used in petrochemical, liquefied natural gas (LNG), and air separation plants. Its core structure consists of a helically wound bundle of heat exchange tubes. A special spatial arrangement achieves high heat exchange efficiency and a compact volume. The heat exchange tubes are spirally wound around a central cylinder. One fluid flows inside the tubes, while another flows on the shell side, exchanging heat through the tube walls. A counter-current arrangement (two fluids flowing in opposite directions) is typically used to maximize the temperature difference for heat transfer and improve efficiency.

[0003] However, in most heat exchangers, the shell-side fluid flows in a straight line along the axial direction (parallel to the heat exchange tubes), forming a laminar boundary layer, which leads to a decrease in the heat transfer coefficient. Furthermore, because there is fluid flow in the shell side for a long time, low-velocity zones or dead zones are easily formed in the tube bundle gaps or shell edges, resulting in local heat transfer deterioration. Over time, this can easily lead to fouling accumulation, affecting the heat conduction effect. Utility Model Content

[0004] This application provides a spiral flow-guided tube heat exchanger, which can solve the technical problem in the prior art where the shell side of the existing heat exchanger has axial flow, which not only has limited heat exchange effect, but also causes local heat exchange deterioration and even fouling accumulation.

[0005] This application provides a spiral flow guide tube heat exchanger, including:

[0006] A heat exchange assembly includes a longitudinally penetrating shell and a central cylinder located inside the shell. Multiple layers of heat exchange tubes are arranged around the outer periphery of the central cylinder, and the multiple layers of heat exchange tubes are arranged at radial intervals along the shell.

[0007] A flow guiding assembly includes a flow guiding strip, which is spirally arranged around the central cylinder, and a flow guiding strip is provided between two adjacent layers of heat exchange tubes and between the innermost heat exchange tube and the central cylinder.

[0008] In one embodiment, the top of the shell is gathered to form a tube inlet, and a first flow-dividing baffle is provided below the tube inlet. The inlet ends of the multiple heat exchange tubes pass through the first flow-dividing baffle and are connected to the tube inlet.

[0009] In one embodiment, the bottom of the shell converges to form a tube-side outlet, and a second flow-diverting baffle is provided above the tube-side outlet. The outflow ends of the multiple heat exchange tubes pass through the second flow-diverting baffle and are connected to the tube-side outlet.

[0010] In one embodiment, the shell side outlet communicating with the inner cavity of the shell is provided laterally on the pipe wall near the first diversion baffle, and the horizontal height of the shell side outlet is lower than the horizontal height of the first diversion baffle. The shell side inlet communicating with the inner cavity of the shell is provided laterally on the pipe wall near the second diversion baffle, and the horizontal height of the shell side inlet is higher than the horizontal height of the second diversion baffle.

[0011] In one embodiment, the top of the central cylinder is connected to the first diversion baffle, and the bottom of the central cylinder is connected to the second diversion baffle.

[0012] In one embodiment, a first perforated plate is provided below the first diversion baffle, the top of the central cylinder passes through the first perforated plate and is connected to the first diversion baffle, and the first perforated plate is located below the shell outlet.

[0013] In one embodiment, a second perforated plate is provided above the second diversion baffle, the bottom of the central cylinder passes through the second perforated plate and is connected to the second diversion baffle, and the second perforated plate is located above the shell inlet.

[0014] In one embodiment, a space for accommodating the flow guiding component is formed between the first perforated plate and the second perforated plate.

[0015] In one embodiment, a multi-layer spacing assembly is provided between the first hollow plate and the second hollow plate, and a spacing assembly is provided on the inner side of each heat exchange tube facing the central cylinder.

[0016] In one embodiment, the spacing component includes multiple spacing strips, with the two ends of each spacing strip fixedly connected to a first hollow plate and a second hollow plate, and the multiple spacing strips in the same group are equidistantly arranged around the outer circumference of the central cylinder.

[0017] The beneficial effects of the technical solutions provided in this application include:

[0018] 1. By changing the flow direction of the shell-side fluid through the spirally wound guide band, the shell-side fluid changes from the traditional axial flow to spiral turbulence, which significantly improves the convective heat transfer coefficient and enhances the overall heat transfer performance. The multi-layer heat exchange tubes, together with the guide band, form multi-stage turbulence, increase fluid disturbance, reduce the thermal boundary layer thickness, and avoid local heat transfer deterioration.

[0019] 2. The guide belt guides the shell-side fluid to form a self-cleaning flow field, reducing dead zones and the risk of dirt and impurities accumulating on the pipe wall and in the shell. The scouring effect of the spiral flow can delay scaling, reduce cleaning frequency, and improve the long-term stability of the equipment.

[0020] 3. The guide strip forms multi-point support and constraint through spiral winding, which effectively suppresses tube bundle vibration caused by fluid pulsation or start-up and shutdown conditions, and avoids fatigue fracture at the connection between heat exchange tube and tube sheet. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a spiral flow guide tube heat exchanger provided in an embodiment of this application;

[0023] Figure 2 A schematic diagram of the shell structure in a spiral flow guide tube heat exchanger provided in this application embodiment;

[0024] Figure 3 This is a top view of a spiral flow guide tube heat exchanger provided in an embodiment of this application.

[0025] In the diagram: 1. Shell; 2. Central cylinder; 3. Heat exchange tube; 4. Flow guide strip; 5. Tube side inlet; 6. First flow divider baffle; 7. Tube side outlet; 8. Second flow divider baffle; 9. Shell side outlet; 10. Shell side inlet; 11. First perforated plate; 12. Second perforated plate; 13. Spacing bar. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0027] This application provides a spiral flow-guided tube heat exchanger, which can solve the technical problem in the prior art where the shell side of the existing heat exchanger has axial flow, which not only has limited heat exchange effect, but also causes local heat exchange deterioration and even fouling accumulation.

[0028] The spiral flow-guided tube heat exchanger of this application includes a heat exchange component and a flow-guided component. The heat exchange component forms a shell side and a tube side for independent flow of two fluids for heat exchange. The flow-guided component is formed in the shell side to redirect and guide the shell-side fluid. This not only extends the flow path of the shell-side fluid, making it flow in a spiral form, thereby improving the shell-side heat transfer coefficient, but also, due to the change in the flow state of the shell-side fluid, the shell-side fluid cuts and brushes the tube wall laterally or obliquely, increasing the degree of turbulence in the shell-side fluid and delaying the time of fouling.

[0029] Figure 1 This application provides a schematic diagram of a spiral flow guide tube heat exchanger structure, as shown in the embodiment of the present application. Figure 1 As shown, the heat exchange assembly in this application includes a longitudinally penetrating shell 1 and a central cylinder 2 located inside the shell 1. The shell 1 is a cylindrical tube with standardized flange connection ports at both axial ends. The wall thickness of the cylinder is determined by strength calculation based on the medium parameters. The central cylinder 2 is arranged coaxially with the shell 1, and the diameter of the central cylinder 2 forms a specific annular gap ratio with the shell 1. Multiple layers of heat exchange tubes 3 are arranged around the outer periphery of the central cylinder 2. The heat exchange tubes 3 are arranged radially in at least three layers of spirally wound heat exchange tubes 3 with the central cylinder 2 as the axis. The innermost heat exchange tube 3 is also spaced a certain distance from the central cylinder 2, and the interlayer spacing of the multiple layers of heat exchange tubes 3 is consistent. The heat exchange tubes 3 are made of a high thermal conductivity material. In one possible embodiment, the spiral winding angle of the heat exchange tubes 3 is 5°-30°, taking into account both flow resistance and heat exchange efficiency. The shell-side fluid flows along the annular space between the shell 1 and the central cylinder 2, while the tube-side fluid flows inside the heat exchange tubes 3.

[0030] The flow guiding assembly includes a flow guiding strip 4, which is spirally arranged around the central cylinder 2 with the central cylinder 2 as the axis. A flow guiding strip 4 is provided between two adjacent heat exchange tubes 3 and between the innermost heat exchange tube 3 and the central cylinder 2. The flow guiding strip 4 is a spiral plate with a certain width that is smaller than the interlayer spacing between the center lines of the two heat exchange tubes 3. The flow guiding plate 4 has a semi-circular hole that is adapted to the heat exchange tube 3 on the side wall of the heat exchange tube 3. Taking a three-layer heat exchange tube as an example, there are three flow guiding strips 4. One flow guiding strip 4 is located between the innermost heat exchange tube 3 and the central cylinder 2, the second flow guiding strip 4 is located between the innermost heat exchange tube 3 and the middle heat exchange tube 3, the third flow guiding strip 4 is located between the middle heat exchange tube 3 and the outermost heat exchange tube 3, and so on. The flow guiding strip 4 can be directly snapped between two heat exchange tubes 3, or it can be welded or fixed to the heat exchange tube 3 using snap-fit ​​parts. This application does not impose any restrictions.

[0031] In one possible implementation, the spiral winding angle of the guide strip 4 is consistent with that of the heat exchange tube 3, and the guide strip 4 strictly follows the spiral winding trajectory of the heat exchange tube 3, with both maintaining a completely consistent spiral angle. In another implementation of this application, the spiral winding angle of each guide strip 4 is different, which can break the periodic rotation law of the fluid, induce a more complex turbulent structure, reduce the thickness of the laminar boundary layer, and improve the overall heat transfer coefficient. For example, the inner guide strip 4 uses a small angle (such as 10°-15°) to reduce the pressure drop in the inlet section, and the outer guide strip 4 increases the angle (such as 20°-30°) to enhance the end heat transfer, thereby achieving a gradual distribution of flow resistance and avoiding sudden changes in local pressure drop.

[0032] Furthermore, Figure 2 This application provides a schematic diagram of the shell 1 structure in a spiral flow guide tube heat exchanger, as shown in the embodiment. Figure 2 As shown, the top of the shell 1 converges to form a tube-side inlet 5. Below the tube-side inlet 5, there is a first flow-dividing baffle 6. The inlet ends of multiple heat exchange tubes 3 pass through the first flow-dividing baffle 6 and connect to the tube-side inlet 5. The tube-side inlet 5 is provided with a flange connection port for connecting to the external tube-side fluid outlet end. The first flow-dividing baffle 6 is a closed circular plate structure. Its outer circumference is connected to the inner wall of the top of the shell 1. The first flow-dividing baffle 6 divides the space at the top of the shell 1 into a tube-side inlet chamber with a top opening. The top end of the heat exchange tube 3 detaches from the outer circumference of the central cylinder 2 and extends upward to pass through the first flow-dividing baffle 6 and enter the tube-side inlet chamber. The fluid flowing in through the tube-side inlet 5 directly enters the multiple heat exchange tubes 3.

[0033] Furthermore, the bottom of the shell 1 converges to form the tube outlet 7. A second diversion baffle 8 is provided above the tube outlet 7. The outlet ends of multiple heat exchange tubes 3 pass through the second diversion baffle 8 and connect to the tube outlet 7. It can be understood that the shell 1 is arranged in a mirror symmetrical manner. The tube outlet 7 and the tube inlet 5 have the same function, which is to connect to the external tube outlet end. The second diversion baffle 8 and the first diversion baffle 6 have the same function, which is to divide the tube outlet chamber. The bottom end of the heat exchange tube 3 detaches from the outer periphery of the central cylinder 2 and extends downward to pass through the second diversion baffle 8 and enter the tube outlet chamber.

[0034] Furthermore, a shell-side outlet 9 is laterally provided on the pipe wall near the first diversion baffle 6, communicating with the inner cavity of the shell 1. A shell-side inlet 10 is laterally provided on the pipe wall near the second diversion baffle 8, communicating with the inner cavity of the shell 1. The pipe-side fluid and the shell-side fluid flow in opposite directions. Taking the above structure as an example, the pipe-side fluid flows from top to bottom, while the shell-side fluid flows from bottom to top. The outlet 9 is located at the top of the shell 1, and the inlet 10 is located at the bottom of the shell 1. The pipe-side inlet and outlet are located above the first diversion baffle 6 and below the second diversion baffle 8. The space between the first diversion baffle 6 and the second diversion baffle 8 is the shell side. Therefore, the horizontal height of the shell-side outlet 9 is lower than the horizontal height of the first diversion baffle 6, and the horizontal height of the shell-side inlet 10 is higher than the horizontal height of the second diversion baffle 8, so as to separate the pipe side and the shell side.

[0035] Furthermore, the top of the central cylinder 2 is connected to the first diversion baffle 6, and the bottom of the central cylinder 2 is connected to the second diversion baffle 8. The two ends of the central cylinder 2 are respectively connected to the center positions of the first diversion baffle 6 and the second diversion baffle 8. There are multiple heat exchange tubes 3. The inlet ends of the multiple heat exchange tubes 3 pass through the first diversion baffle 6 around the outer circumference of the top of the central cylinder 2, and the outlet ends of the multiple heat exchange tubes 3 pass through the second diversion baffle 8 around the outer circumference of the bottom of the central cylinder 2.

[0036] In one possible implementation, to facilitate the cleaning and maintenance of the overall structure, the first diversion baffle 6, the second diversion baffle 8, and the central cylinder 2 are all detachably connected. That is, the outer circumference of the first diversion baffle 6 and the second diversion baffle 8 are both provided with external threads, and the inner walls of the top and bottom of the housing 1 at opposite positions are provided with corresponding internal threads. Furthermore, the top of the first diversion baffle 6 and the second diversion baffle 8 are provided with internal hexagonal grooves to facilitate the rotation of the first diversion baffle 6 and the second diversion baffle 8.

[0037] Furthermore, the first diversion baffle 6 has a first threaded groove at its center bottom, and the center cylinder 2 has a matching protruding first external threaded block at its top. The second diversion baffle 8 has a second threaded groove at its center top, and the center cylinder 2 has a matching protruding second external threaded block at its bottom, so as to achieve a detachable connection between the three.

[0038] It should be noted that the position of the second threaded groove on the second diversion baffle 8 coincides with the position of the aforementioned internal hexagonal groove. Therefore, the depth of the second threaded groove is less than the thickness of the second diversion baffle 8. The internal hexagonal groove is located at the bottom of the second threaded groove but does not penetrate the second diversion baffle 8. Furthermore, when the entire internal plate of the housing 1 is detachable, the components at the top and bottom ends of the housing 1 are also detachable to facilitate the insertion of the internal plate of the housing 1.

[0039] Meanwhile, the flow direction of the tube-side fluid and the shell-side fluid is not necessarily the above-mentioned direction. The tube-side fluid can also flow from bottom to top, in which case the top of the shell 1 is the tube-side outlet 7 and the bottom of the shell 1 is the tube-side inlet 5. If the shell-side fluid flows from top to bottom, then the top is the shell-side inlet 10 and the bottom is the shell-side outlet 9. The specific flow direction depends on the actual needs, and this application does not impose any specific flow direction restrictions.

[0040] Furthermore, a first perforated plate 11 is provided below the first diversion baffle 6, and a second perforated plate 12 is provided above the second diversion baffle 8. The first perforated plate 11 and the second perforated plate 12 can be fixedly installed or threaded to the inner wall of the shell 1. Further details are omitted here. The first perforated plate 11 is located below the shell-side outlet 9, and the second perforated plate 12 is located above the shell-side inlet 10. The space between the first perforated plate 11 and the second perforated plate 12 is used to install the heat exchange tube 3 and the flow guide 4. The shell-side fluid flowing in from the shell-side inlet 10 contacts the flow guide 4 through the second perforated plate 12 and changes its flow direction under the guidance of the flow guide 4.

[0041] Furthermore, multiple spacing components are provided between the first hollow plate 11 and the second hollow plate 12, and each heat exchange tube 3 has a corresponding spacing component on its inner side facing the central cylinder 2. The spacing components are used to maintain the distance between adjacent heat exchange tubes 3 and provide a fulcrum for the heat exchange tubes 3. Specifically, the spacing components include multiple spacing strips 13, with both ends of the spacing strips 13 fixedly connected to the first hollow plate 11 and the second hollow plate 12, and the multiple spacing strips 13 in the same group are equidistantly arranged around the outer circumference of the central cylinder 2. Figure 3 A top view of a spiral flow guide tube heat exchanger provided in an embodiment of this application, as shown below. Figure 3 As shown, in the same group of structures, the guide strip 4 is closest to the central cylinder 2, followed by the corresponding spacer strip 13, and finally the heat exchange tube 3. Each heat exchange tube 3 corresponds to at least four spacer strips 13, and the four spacer strips 13 are equally distributed on the outer circumference of the central cylinder 2.

[0042] In one possible implementation, taking four spacer bars 13 as an example, four engaging grooves are provided on the side of the guide tube facing the spacer bars 13 to facilitate the insertion of the four spacer bars 13, and a semi-circular hole adapted to the heat exchange tube 3 is provided on the other side to support the corresponding heat exchange tube 3 or the central cylinder 2.

[0043] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0044] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A spiral flow-guided tube heat exchanger, characterized in that, include: The heat exchange assembly includes a longitudinally penetrating shell (1) and a central cylinder (2) located inside the shell (1). The central cylinder (2) is surrounded by multiple layers of heat exchange tubes (3), and the multiple layers of heat exchange tubes (3) are arranged radially at intervals along the shell (1). The flow guiding component includes a flow guiding strip (4), which is spirally arranged around the central cylinder (2), and a flow guiding strip (4) is provided between two adjacent heat exchange tubes (3) and between the innermost heat exchange tube (3) and the central cylinder (2).

2. The spiral flow guide tube heat exchanger as described in claim 1, characterized in that: The top of the shell (1) is gathered to form a tube inlet (5), and a first flow divider (6) is provided below the tube inlet (5). The inlet ends of multiple heat exchange tubes (3) pass through the first flow divider (6) and are connected to the tube inlet (5).

3. The spiral flow guide tube heat exchanger as described in claim 2, characterized in that: The bottom of the shell (1) is gathered to form a tube outlet (7), and a second flow divider (8) is provided above the tube outlet (7). The outflow ends of multiple heat exchange tubes (3) pass through the second flow divider (8) and are connected to the tube outlet (7).

4. The spiral flow guide tube heat exchanger as described in claim 3, characterized in that: The shell (1) has a shell-side outlet (9) that communicates with the inner cavity of the shell (1) on the pipe wall near the first diversion baffle (6) and the horizontal height of the shell-side outlet (9) is lower than the horizontal height of the first diversion baffle (6). The shell (1) has a shell-side inlet (10) that communicates with the inner cavity of the shell (1) on the pipe wall near the second diversion baffle (8) and the horizontal height of the shell-side inlet (10) is higher than the horizontal height of the second diversion baffle (8).

5. A spiral flow guide tube heat exchanger as described in claim 4, characterized in that: The top of the central cylinder (2) is connected to the first diversion baffle (6), and the bottom of the central cylinder (2) is connected to the second diversion baffle (8).

6. A spiral flow guide tube heat exchanger as described in claim 5, characterized in that: A first hollow plate (11) is provided below the first diversion baffle (6), the top of the central cylinder (2) passes through the first hollow plate (11) and is connected to the first diversion baffle (6), and the first hollow plate (11) is located below the shell side outlet (9).

7. A spiral flow guide tube heat exchanger as described in claim 6, characterized in that: A second hollow plate (12) is provided above the second diversion baffle (8). The bottom of the central cylinder (2) passes through the second hollow plate (12) and is connected to the second diversion baffle (8). The second hollow plate (12) is located above the shell inlet (10).

8. A spiral flow guide tube heat exchanger as described in claim 7, characterized in that: A space for accommodating the flow guide component is formed between the first hollow plate (11) and the second hollow plate (12).

9. A spiral flow guide tube heat exchanger as described in claim 7, characterized in that: A multi-layer spacing assembly is provided between the first hollow plate (11) and the second hollow plate (12), and a spacing assembly is provided on the inner side of each heat exchange tube (3) facing the central cylinder (2).

10. A spiral flow guide tube heat exchanger as described in claim 9, characterized in that: The distance-fixing component includes multiple distance-fixing strips (13), with the two ends of the distance-fixing strips (13) being fixedly connected to the first hollow plate (11) and the second hollow plate (12) respectively, and the multiple distance-fixing strips (13) in the same group are equidistantly arranged around the outer circumference of the central cylinder (2).

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