A heat exchange device

Abstract

The present invention provides a heat exchange device, which belongs to the technical field of mechanical heat exchange equipment. It solves the problem of low heat exchange efficiency of existing heat exchange devices. The heat exchange device includes a shell, a heat exchange tube arranged in the shell along the length direction of the shell, and a baffle spirally arranged in the shell along the length direction of the shell. One end of the shell has a shell-side fluid inlet and the other end has a shell-side fluid outlet. A plurality of fins are arranged on the outer wall of the heat exchange tube. The heat exchange tube is spaced around the axis of the shell. The fin is in the shape of a long strip. The side of the fin facing the shell-side fluid inlet has a guide surface for making the shell-side fluid flow away from the heat exchange tube. The baffle is spaced along the extension direction of the baffle with baffles close to the axis of the shell for the shell-side fluid to pass through. The present invention can make the shell-side fluid form a radial vortex, so that the shell-side fluid contacts the heat exchange tube more fully and the utilization rate is higher, and the heat exchange effect is better.

Description

Technical Field

[0001] The invention belongs to the technical field of heat exchange equipment and relates to a shell and tube heat exchange device. Background Art

[0002] A heat exchanger is an energy-saving device that transfers heat between two or more fluids at different temperatures. It transfers heat from a fluid with a higher temperature to a fluid with a lower temperature, so that the fluid temperature reaches the specified index of the process to meet the needs. It is also one of the main equipment for improving energy utilization and is mainly used in petroleum, chemical, HVAC and other industries.

[0003] Heat exchange devices are mainly divided into three categories: partition type, hybrid type and heat storage type. Among them, the shell and tube heat exchanger in the partition type is the most widely used heat exchange device due to its simple structure, low cost, wide fluid cross-section, easy to clean scale, and wide range of use. The shell and tube heat exchanger is mainly composed of a shell and heat exchange tubes arranged in the shell. During heat exchange, one of the cold and hot fluids flows in the tube, called the tube-side fluid, and the other flows outside the tube, called the shell-side fluid. The tube-side fluid and the shell-side fluid are heat exchanged through the heat exchange tube as a heat transfer surface. However, due to this structure, there is a problem of low heat transfer coefficient between the shell-side fluid and the tube-side fluid.

[0004] In order to solve the above problems, those skilled in the art usually adopt a structure in which fins and baffles are arranged outside the heat exchange tubes. For example, a Chinese patent application (application number: 200310105835.5) discloses a shell and tube heat exchanger, which includes a shell, a central gas channel located in the center of the shell, baffles located at both ends of the shell, an inner fin tube bundle fixed parallel to the two baffles, and a spiral baffle located between the inner fin tube bundle and the outer shell, so that the shell-side fluid passes through the baffle to improve the heat exchange efficiency with the heat exchange tubes. Although the shell-side fluid will form turbulence around the shell flow channel when passing through the baffle, which improves the heat exchange efficiency to a certain extent, since the shell-side fluid always only flows around the axis of the shell, the part of the shell-side fluid close to the heat exchange tube is always in contact with the heat exchange tube, so that its temperature is close to the temperature of the heat exchange tube, resulting in a decrease in heat exchange efficiency, and the part of the shell-side fluid away from the axis is always not in contact with the heat exchange tube, resulting in a low utilization rate of the shell-side fluid in this part, that is, the overall heat exchange efficiency of the shell-side fluid is still not high, and when the shell-side fluid flows along the baffle spirally, the flow rate of the shell-side fluid close to the axis of the shell is relatively slow, so that the inner side of the heat exchange tube cannot fully exchange heat with the shell-side fluid, resulting in the overall heat exchange efficiency is still low. The Chinese patent application (application number 201610793710.3) also discloses a spiral fin structure heat exchanger with a similar structure, but the patent still has the same problem. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the prior art and to propose a heat exchange device. The technical problem to be solved by the present invention is: how to improve the heat exchange efficiency of the heat exchange device.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A heat exchange device comprises a shell, a heat exchange tube arranged in the shell along the length direction of the shell, and a baffle plate spirally arranged in the shell along the length direction of the shell, one end of the shell has a shell-side fluid inlet and the other end has a shell-side fluid outlet, a plurality of fins are arranged on the outer wall of the heat exchange tube, and it is characterized in that the heat exchange tube is spaced around the axis of the shell, the fins are in the shape of long strips, the side of the fin facing the shell-side fluid inlet direction has a guide surface for making the shell-side fluid flow away from the heat exchange tube, and the baffle plate is spaced along the extension direction of the baffle plate with baffle openings close to the axis of the shell and for the shell-side fluid to pass through.

[0008] The shell of the heat exchange device is cylindrical, and the heat exchange tube is arranged in the shell along the axial direction of the shell and around the axis of the shell. The baffle is also spirally arranged in the shell along the length direction of the shell. Since the fins with guide surfaces are arranged on the outer wall of the heat exchange tube, when the shell-side fluid passes through the fins along the baffle spiral, the shell-side fluid after heat exchange with the fins will flow along the guide surface of the fins in the direction away from the heat dissipation tube, so that the shell-side fluid that has not exchanged heat with the fins can be supplemented to exchange heat with the fins. In addition, since the baffle is provided with a baffle port close to the axis of the shell, the shell-side fluid can flow along the baffle spiral. When flowing, part of the shell-side fluid will directly flow toward the axial direction of the shell and enter the gap between the baffles of the next layer through the baffle port, so that the shell-side fluid forms a vortex in the radial direction of the shell, thereby improving the utilization rate of each position of the shell-side fluid. Moreover, the structural design also ensures that the shell-side fluid close to the axial centerline in the shell has a larger flow rate, so that the fins of the heat dissipation pipe close to the axial side of the shell can still contact a large amount of shell-side fluid, which not only ensures the overall utilization rate of the shell-side fluid, but also makes the heat exchange of each part of the heat exchange tube more uniform, and the utilization efficiency of the fins is also higher, thereby improving the heat exchange efficiency of the heat exchange device.

[0009] Moreover, since the guide surface of the fin faces the direction of the shell-side fluid inlet, and the direction of the main flow channel of the shell-side fluid is the spiral flow channel along the baffle, the shell-side fluid has a certain angle with the guide surface of the fin when flowing toward the fin, which makes the pressure drop of the shell-side fluid smaller and the flow smoother.

[0010] In the above heat exchange device, the width of the baffle increases in the direction from the outside of the baffle to the axis of the shell. In this way, the flow guiding effect of the baffle can be ensured, and part of the shell-side fluid can flow more easily in the axial direction of the shell, and the flow effect of the shell-side fluid in the radial direction is better, so that the shell-side fluid located on the outside can be more easily contacted with the fins for heat exchange, thereby improving the heat exchange efficiency.

[0011] In the above heat exchange device, the baffle plate includes a plurality of fan-shaped baffles, and the baffles are connected end to end through the two ends of the arc edge to form a spiral shape, and the adjacent baffles are relatively inclined to form the above baffle opening between the adjacent two baffles. The baffle plate has a simple structure and is formed by welding the fan-shaped baffles, so that the baffle opening is naturally formed between the baffles, and the processing is simpler and more convenient.

[0012] In the above heat exchange device, the angle between the side edges of two adjacent baffles is 10-40°.

[0013] In the above heat exchange device, the projection of the baffle along the length direction of the shell is a sector with a central angle of 90°. In this way, the four baffles can form a complete spiral cycle. The baffles of the upper and lower layers are located on the same axis, which is convenient for the installation of the heat exchange tube.

[0014] In the above heat exchange device, the baffle is also provided with a plurality of support rods arranged along the length direction of the heat exchange tube, the baffle is provided with a mounting hole and a clearance hole, the support rod passes through the mounting hole and is fixedly connected to the baffle, and the aperture of the clearance hole is larger than the outer diameter of the heat exchange tube and is used for the heat exchange tube to pass through. The baffle is provided with a plurality of support rods to support the baffle, so that the structure of the baffle is more stable, and the aperture of the clearance hole is larger, so that the heat exchange tube provided with fins can pass through the baffle, and the fins can be prevented from interfering with the installation of the heat exchange tube.

[0015] In the above heat exchange device, the guide surface of the fin is in an inwardly concave arc, one end of the guide surface smoothly transitions with the outer wall of the heat exchange tube and the other end of the guide surface extends in a direction away from the heat exchange tube. The guide surface is in an arc shape, so that it can more smoothly change the flow direction of the shell-side fluid, so that the shell-side fluid flows in a direction away from the heat exchange tube, and the guide surface is in an arc shape, which can increase the surface area of ​​the fin and improve the heat exchange effect.

[0016] In the above heat exchange device, the thickness of the fin decreases from the end close to the heat exchange tube to the end far from the heat exchange tube. The end of the fin connected to the heat exchange tube is thicker, which is convenient for heat transfer between the fin and the heat exchange tube, while the end of the fin far from the heat exchange tube is thinner, which increases the contact area between the fin and the shell-side fluid per unit volume, thereby improving the heat exchange efficiency of the heat exchange tube. Moreover, such a design makes the area of ​​the side of the fin smaller, and the resistance of the shell-side fluid when passing through the fin along the spiral direction of the baffle is smaller, so that the pressure drop of the shell-side fluid is also smaller, avoiding excessive reduction of the flow rate of the shell-side fluid, thereby ensuring the heat exchange efficiency.

[0017] In the above heat exchange device, the side of the fin opposite to the guide surface has a back flow surface, which is also arc-shaped and has the same bending direction as the guide surface. Such a design also increases the area of ​​the back of the fin and improves the heat exchange effect of the fin.

[0018] In the above heat exchange device, the fins are spirally distributed along the outer wall of the heat exchange tube.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The present invention arranges fins with guide surfaces on the outer wall of the heat exchange tube and arranges baffles on the spirally arranged baffles, so that the shell-side fluid can generate eddy currents flowing along the radial direction of the shell while flowing along the spiral baffles, so that the shell-side fluids on the inner and outer sides can exchange heat with the heat exchange tube, and the fins on each circumferential direction of the heat exchange tube can fully contact with the shell-side fluid, the heat exchange efficiency of the heat exchange device is higher, the overall temperature of the tube-side fluid is more uniform, and the heat exchange effect is better.

[0021] 2. The baffle is formed by connecting a plurality of fan-shaped baffles, and the baffle opening is formed by tilting adjacent baffles, so that the width of the baffle opening increases from the outside to the inside, making it easier for the shell-side fluid to flow toward the axial direction of the shell, which is convenient for the formation of radial vortex. In addition, the baffle has a simple structure, is easy to process, and has a low production cost.

[0022] 3. The guide surface of the fin faces the shell-side fluid inlet direction and the fin is thick at the bottom and thin at the top, so that the fin can not only guide the shell-side fluid, but also improve the heat exchange efficiency between the heat exchange tube and the shell-side fluid, and the pressure drop of the shell-side fluid is small, ensuring the flow rate of the shell-side fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the structure of the heat pipe;

[0025] Figure 3 It is a schematic diagram of the structure of the baffle.

[0026] In the figure, 1, shell; 11, shell-side fluid inlet; 12, shell-side fluid outlet; 2, heat exchange tube; 3, fin; 31, guide surface; 32, back flow surface; 4, baffle; 41, baffle; 411, give way hole; 412, mounting hole; 42, baffle port; 5, support rod. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0028] A heat exchange device, such as Figure 1 , Figure 2 As shown, it includes a shell 1, a baffle 4 and a plurality of heat exchange tubes 2, wherein the shell 1 is cylindrical, one end of the shell 1 has a shell-side fluid inlet 11 and the other end has a shell-side fluid outlet 12, the baffle 4 is spirally arranged in the shell 1 along the length direction of the shell 1, and the heat exchange tube 2 is also arranged in the shell 1 along the length direction of the shell 1, and fins 3 are arranged circumferentially on the outer circumferential surface of the heat exchange tube 2, and the fin 3 has a guide surface 31 that keeps the shell-side fluid away from the heat dissipation tube and forms a disturbance, and the baffle 4 is provided with a plurality of baffle ports 42 for the shell-side fluid to pass through at intervals along its extension direction, so that the shell-side fluid forms a disturbance when it flows from the shell-side fluid inlet 11 to the shell-side fluid outlet, so that the shell-side fluid can exchange heat with the tube-side fluid in the heat exchange tube 2 more evenly and without dead angles.

[0029] Specifically, Figure 2 As shown, the baffle 4 includes a plurality of baffles 41 connected in sequence, and the baffles 41 are all fan-shaped. The two ends of the arc-shaped edges of the baffles 41 are fixedly connected to the adjacent baffles 41 by welding in sequence to form a spiral shape, and the adjacent baffles 41 are arranged inclined to form a baffle opening 42 between the side edges of the adjacent baffles 41. The width of the baffle opening 42 increases successively from the outer side of the baffle 4 to the axial center line of the baffle 4. The angle between the side edges of adjacent baffles 41 is 10 to 40°. In this embodiment, the angle is 30°. The heat exchange tubes 2 are spaced around the axis of the shell 1 and are passed through the baffle 4. A plurality of fins 3 are fixedly arranged on the outer wall of the heat exchange tube 2. The fins 3 are spaced along the circumference and length of the heat exchange tube. The fins 3 are in the shape of long strips. One end of the fin 3 is fixedly connected to the heat exchange tube and the other end extends outward. The two wider side surfaces of the fin 3 are the guide surface 31 and the back flow surface 32, wherein the guide surface 31 faces the shell-side fluid inlet 11 and the back flow surface 32 faces the shell-side fluid outlet 12. The guide surface 31 of the fin 3 is in the shape of an arc concave inwardly, one end of the guide surface 31 smoothly transitions with the outer wall of the heat exchange tube 2 and the other end of the guide surface 31 extends in the direction away from the heat exchange tube 2.

[0030] When the heat exchange device is working, the tube-side fluid that needs to be exchanged for heat is introduced into the heat exchange tube 2, and the shell-side fluid outside the heat exchange tube 2 is introduced into the shell 1. The tube-side fluid transfers heat to the heat exchange tube 2 by contacting with the heat exchange tube 2. When the tube-side fluid flows from the shell-side fluid inlet 11 to the shell-side fluid outlet 12, most of the shell-side fluid flows in a spiral along the baffle 4. During the flow, part of the shell-side fluid will contact the fin 3 on the outer wall of the heat exchange tube 2, so that the shell-side fluid exchanges heat with the fin 3 along the direction of the guide surface 31 while flowing away from the heat exchange tube 2. Since the baffle 4 has a baffle 42, part of the shell-side fluid along the flow channel of the baffle 4 will directly flow in the direction of the baffle 42 and directly enter the next layer of baffle 4. The gap between the shell and the heat exchange tube 2, that is, the shell-side fluid flows along the radial direction of the shell 1 toward the axial direction of the shell 1, and then complements the shell-side fluid near the heat exchange tube fin 3, so that the shell-side fluid forms a vortex in the radial direction of the shell 1, and the shell-side fluid located outside the heat exchange tube 2 and not exchanging heat with the heat exchange tube 2 flows toward the axial side of the shell 1, and then contacts the heat exchange tube 2 and exchanges heat, and the vortex in the radial direction makes the shell-side fluid on the axial side of the shell 1 also have a large flow rate, so that the heat exchange tube 2 located on the side close to the axial side of the shell 1 can also fully contact with the shell-side fluid, so that the heat exchange effect of each part of the heat exchange tube 2 in the circumferential direction is basically the same, and the temperature of each part of the tube-side fluid in the heat exchange tube 2 is closer, so that the heat exchange effect and heat exchange efficiency are greatly improved.

[0031] Further, such as Figure 3 As shown, in this embodiment, a plurality of support rods 5 are also provided on the baffle plate 4, and the support rods 5 are arranged at intervals along the length direction of the shell 1 and around the axis of the shell 1. The projection of the baffle plate 41 along the length direction of the shell 1 is in the shape of a fan with a central angle of 90°, so that the four baffle plates 41 form a spiral period of the baffle plate 41, and the baffle plate 41 is provided with two clearance holes 411 and a mounting hole 412, wherein the clearance holes 411 are located outside the mounting hole 412, and the aperture of the clearance holes 411 is larger than the outer diameter of the heat exchange tube 2, so that the heat exchange tube 2 equipped with the fin 3 can freely pass through the clearance holes 411 to avoid interference when the heat exchange tube 2 is installed, and the support rods 5 pass through the clearance holes 411 and are fixedly connected to the baffle plates 41 by welding, so that the baffle plates 41 of each spiral period are fixed on the support rods 5 and form a whole, thereby improving the structural stability of the baffle plate 4 and facilitating the installation of the baffle plate 4 into the shell 1. Of course, in actual use, the number of baffles 41 in each spiral period may also be 3 or 5, and the number of the relief holes 411 and the mounting holes 412 may also be selected according to actual needs.

[0032] Further, such as Figure 2As shown, in this embodiment, the thickness of the fin 3 decreases from the end close to the heat exchange tube 2 to the end far from the heat exchange tube 2, that is, the bottom of the fin 3 is thicker and the top is thinner, and the back flow surface 32 of the fin 3 is also arc-shaped, and the bending direction of the back flow surface 32 is the same as that of the guide surface 31, so that the area of ​​the side of the fin 3 is smaller and the area of ​​the back flow surface 32 of the fin 3 is larger. Such a structure not only ensures the heat conduction efficiency between the fin 3 and the heat exchange tube 2, but also improves the contact area and heat exchange efficiency between the fin 3 and the shell-side fluid. In addition, the side area of ​​the fin 3 is smaller, the resistance to the shell-side fluid is smaller, and the energy loss of the shell-side fluid is also smaller, thereby reducing the pressure drop of the shell-side fluid and ensuring the flow rate.

[0033] Furthermore, in this embodiment, the fins 3 are evenly spaced along the circumference of the heat exchange tube 2, and are spaced along the axis of the heat exchange tube 2. Of course, the fins 3 can also be arranged in a spiral spacing along the outer wall of the heat exchange tube 2, or can be arranged evenly spaced along the circumference of the heat exchange tube 2 and staggered along the length direction of the heat exchange tube 2, so that the fins 3 of each layer are located between two adjacent fins 3 of an adjacent layer in the projection of the length direction of the heat exchange tube 2, so that part of the shell-side fluid can pass through the gaps between the fins 3 and contact with the fins 3 of the next layer for heat exchange, further improving the utilization rate of the fins 3.

[0034] Furthermore, in this embodiment, both ends of the shell 1 are fixed with a hollow mounting plate, which is not shown in the drawings of the specification. The two ends of the heat exchange tube 2 are respectively passed through the mounting plate and fixedly connected to the mounting plate, so that the heat exchange tube 2 is fixed in the shell 1.

[0035] Furthermore, inner fins may be provided in the heat exchange tube 2 . The inner fins are conventional technology and are used to increase the heat exchange efficiency between the tube-side fluid and the heat exchange tube 2 .

[0036] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0037] Although the terms such as shell 1, shell-side fluid inlet 11, shell-side fluid outlet 12, heat exchange tube 2, fin 3, flow guide surface 31, back flow surface 32, baffle 4, baffle 41, baffle port 42, support rod 5 are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A heat exchange device, comprising a shell (1), a heat exchange tube (2) arranged in the shell (1) along the length direction of the shell (1), and a baffle (4) spirally arranged in the shell (1) along the length direction of the shell (1), one end of the shell (1) has a shell-side fluid inlet (11) and the other end has a shell-side fluid outlet (12), the outer side wall of the heat exchange tube (2) is provided with a plurality of fins (3), characterized in that: The heat exchange tubes (2) are spaced apart around the axis of the shell (1); the fins (3) are in the shape of long strips; the side of the fins (3) facing the shell-side fluid inlet (11) has a guide surface (31) for causing the shell-side fluid to flow in a direction away from the heat exchange tube (2); the baffles (4) are spaced apart along the extension direction of the baffles (4) and are close to the axis of the shell (1) and are for the shell-side fluid to pass through; the guide surfaces (31) of the fins (3) are in the shape of an arc that is concave inwards; the concave directions of the guide surfaces (31) of the plurality of fins (3) are all the same, so that the guide surfaces (31) are all facing the shell-side fluid inlet; one end of the guide surface (31) smoothly transitions to the outer wall of the heat exchange tube (2) and the other end of the guide surface (31) extends in a direction away from the heat exchange tube (2).

2. The heat exchange device according to claim 1, characterized in that: The width of the deflection port (42) increases gradually along the direction from the outer side of the deflection plate (4) to the axial center line of the shell (1).

3. The heat exchange device according to claim 2, characterized in that: The baffle plate (4) comprises a plurality of fan-shaped baffles (41), wherein the plurality of baffles (41) are connected end to end in sequence through the two ends of the arc-shaped edges to form a spiral shape, and adjacent baffles (41) are arranged to be relatively inclined so that the above-mentioned baffle opening (42) is formed between two adjacent baffles (41).

4. The heat exchange device according to claim 3, characterized in that: The included angle between the side edges of two adjacent baffles (41) is 10-40°.

5. The heat exchange device according to claim 3 or 4, characterized in that: The projection of the baffle (41) along the length direction of the shell (1) is in the shape of a sector with a central angle of 90°.

6. The heat exchange device according to claim 5, characterized in that: The baffle plate (4) is also provided with a plurality of support rods (5) arranged along the length direction of the shell (1); the baffle plate (41) is provided with a mounting hole (412) and a clearance hole (411); the support rod (5) passes through the mounting hole (412) and is fixedly connected to the baffle plate (41); the aperture of the clearance hole (411) is larger than the outer diameter of the heat exchange tube (2) and is for the heat exchange tube (2) to pass through.

7. The heat exchange device according to claim 1, characterized in that: The thickness of the fin (3) decreases gradually from an end close to the heat exchange tube (2) to an end far from the heat exchange tube (2).

8. The heat exchange device according to claim 7, characterized in that: The fin (3) has a backflow surface (32) on the side opposite to the flow guide surface (31); the backflow surface (32) is also arc-shaped and has the same bending direction as the flow guide surface (31).

9. The heat exchange device according to claim 1, 7 or 8, characterized in that: The fins (3) are distributed in a spiral along the outer wall of the heat exchange tube (2).

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