Vertical heat exchanger with arc flow equalizing plates

Abstract

The invention provides an arc flow equalizing plate vertical heat exchanger which is characterized in that an arc flow equalizing plate is arranged in an upper sealing head, the arc flow equalizing plate is bent upwards from the inner wall of the upper sealing head, the highest point of the arc flow equalizing plate is located at the center point of the cross section of the upper sealing head, and flow equalizing holes which are through up and down are formed in the arc flow equalizing plate; the upper tube plate is an arc plate which is bent downwards from the inner wall of the shell, the upper tube plate and the arc flow equalizing plate are symmetrically arranged along the vertical center line of the upper sealing head, and the upper tube plate is provided with tube holes for the heat exchange tubes to penetrate through. By arranging the arc flow equalizing plate extending upwards and the upper tube plate extending downwards, fluid entering a shell pass can be evenly distributed, and the overall heat exchange effect is improved.

Description

Technical Field

[0001] The invention relates to a shell and tube heat exchanger, in particular to a vertical heat exchanger with an arc flow equalizing plate. Background Art

[0002] Shell and tube heat exchangers are widely used in industries such as chemical, petroleum, refrigeration, nuclear energy and power. Due to the global energy crisis, in order to reduce energy consumption, the demand for heat exchangers in industrial production is increasing, and the quality requirements for heat exchangers are also getting higher and higher. In recent decades, although compact heat exchangers (plate, plate-fin, press-welded plate heat exchangers, etc.), heat pipe heat exchangers, direct contact heat exchangers, etc. have developed rapidly, shell and tube heat exchangers still dominate production and usage due to their high reliability and wide adaptability. According to relevant statistics, the use of shell and tube heat exchangers in industrial devices still accounts for about 70% of all heat exchangers.

[0003] In actual practical use, the heat exchange tube facing the inlet can be allocated more fluid, while the heat exchange tube far from the inlet can be allocated less fluid. The heat exchange tubes located higher can be allocated even less fluid, especially for heat exchangers with a large number of rows of tubes. This leads to uneven fluid distribution and the fluid cannot enter the heat exchange tubes at the same time, affecting the heat exchange efficiency. Therefore, it is very necessary to develop a new shell and tube heat exchanger.

[0004] Some flow equalization methods are still used in traditional baffle heat exchangers to make the fluid distribution uniform. For example, the heat exchanger plate-type flow equalization device is used in the publication number CN204880602U. When the guide plate is set, the distance between the flow channels near the center of the head is small, and the distance between the flow channels near the two ends of the head is large. The two sides are arranged symmetrically. The setting of the guide plate can greatly improve the uniformity of the flow distribution of air entering each flow channel of the heat exchanger. The flow equalization device in the publication number CN207703067U is a conical block structure. The flow equalization device is set inside the upper head. There is a gap between the flow equalization device and the upper head, the upper cover plate and the block graphite; the top of the flow equalization device corresponds to the feed inlet, and the bottom of the flow equalization device corresponds to the block graphite.

[0005] The above structures all adopt a single flow equalization mode, and the structure is complex, the flow equalization effect is single, resulting in poor flow equalization effect. In view of these shortcomings, a flow equalization shell and tube heat exchanger with a simple structure and a synergistic effect of a flow equalization plate and a tube sheet is developed, which makes the fluid distribution more uniform and improves the heat exchange effect, which is of great significance to industrial production and energy conservation and emission reduction. Summary of the invention

[0006] In order to achieve the above object, the technical solution of the present invention is as follows: A vertical heat exchanger with an arc flow balancing plate, the heat exchanger comprises a shell, an upper head and a lower head, the upper head, the shell and the lower head are connected in sequence, a tube side inlet is arranged at the middle position of the top of the upper head, a tube side outlet is arranged at the lower head, the heat exchange tube is arranged in the shell, the heat exchange tube is fixedly connected to the upper tube plate and the lower tube plate, the upper tube plate is arranged between the upper head and the shell, the lower tube plate is arranged between the lower head and the shell, the fluid enters from the tube side inlet, flows through the heat exchange tube, and is mixed with the fluid in the shell Heat exchange is carried out, and then enters the lower head and flows out from the tube outlet; an arc flow equalizing plate is arranged in the upper head, and the arc flow equalizing plate is bent upward from the inner wall of the upper head, and the highest point of the arc flow equalizing plate is located at the center point of the cross section of the upper head, and the arc flow equalizing plate is provided with flow equalizing holes which pass through from top to bottom; the upper tube plate is an arc plate bent downward from the inner wall of the shell, and the upper tube plate and the arc flow equalizing plate are symmetrically arranged along the vertical center line of the upper head, and the upper tube plate is provided with tube holes for the heat exchange tubes to pass through.

[0007] The arc angle of the arc flow equalizing plate is a first arc angle, which is less than 90°, and the arc angle of the upper tube plate is a second arc angle, which is less than 90°.

[0008] The second arc is smaller than the first arc.

[0009] The second arc is 15-30° smaller than the first arc.

[0010] The arc flow equalizing plate is manufactured in an integrated manner.

[0011] The upper tube plate is manufactured in one piece.

[0012] The distance between the highest point of the arc flow equalizing plate and the lowest point of the upper tube plate is 0.38-0.62 times the height of the upper head and 0.92-1.08 times the diameter of the upper head.

[0013] The second arc range is between 100-110 degrees, and the first arc range is between 125-155 degrees.

[0014] Compared with the prior art, the present invention has the following advantages: The present invention adopts an upwardly protruding arc flow equalizing plate and a downwardly protruding arc tube sheet, so that the fluid entering from the tube side inlet first passes through the arc flow equalizing plate for flow equalization, and the arc flow equalizing plate allows more fluid to flow into the heat exchange tube through the edge of the flow equalizing plate close to the inner wall of the head, so that the fluid is evenly distributed. Then the fluid entering the upper tube sheet is evenly distributed again through the downwardly protruding structure of the upper tube sheet to avoid too much fluid entering the heat exchange tube at the edge, ensuring that the middle heat exchange tube can distribute the fluid, so that through the synergistic effect of the flow equalizing plate and the tube sheet, after multiple reciprocating motions of the fluid, the fluid is distributed more evenly in the heat exchange tube, which not only avoids excessive fluid in the center part, but also ensures that there is too much fluid in the edge heat exchange tube close to the inner wall of the head, so that the fluid is evenly exchanged on the whole, and the purpose of enhancing heat transfer is further achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the heat exchanger of the present invention. DETAILED DESCRIPTION

[0016] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0017] A circular arc flow plate vertical heat exchanger, such as Figure 1 As shown, the heat exchanger includes a shell 1, an upper head 2 and a lower head 3, the upper head 2, the shell 1 and the lower head 3 are connected in sequence from top to bottom, a tube side inlet 4 is arranged at the middle position of the top of the upper head 2, and a tube side outlet 5 is arranged on the lower head 3, the heat exchange tube 6 is arranged in the shell 1, and the heat exchange tube 6 is fixedly connected to the upper tube sheet 7 and the lower tube sheet 8, the upper tube sheet 7 is arranged between the upper head 2 and the shell 1, and the lower tube sheet 8 is arranged between the lower head 3 and the shell 1, the fluid enters from the tube side inlet 4, flows through the heat exchange tube 6, exchanges heat with the fluid in the shell 1, and then enters the lower head 3 and flows out from the tube side outlet 5.

[0018] As an improvement, the upper head and the shell cross section are square structures. As an improvement, an arc flow equalizing plate 9 is arranged inside the upper head 2, and an arc flow equalizing plate 9 is arranged inside the upper head. The arc flow equalizing plate is bent upward from both sides of the inner wall of the upper head, and the highest point of the arc flow equalizing plate is located at the center point of the cross section of the upper head. The arc flow equalizing plate is provided with flow equalizing holes that pass through from top to bottom; the upper tube sheet 7 is an arc plate bent downward from the inner wall of the shell, and the upper tube sheet and the arc flow equalizing plate are symmetrically arranged along the vertical center line of the upper head, and the upper tube sheet is provided with tube holes for the heat exchange tubes to pass through. The upper tube sheet is provided with tube holes for the heat exchange tubes 6 to pass through. The lowest point of the upper tube sheet is located at the center point of the cross section of the shell.

[0019] As an improvement, the cross-section of the upper head and the shell is a circular structure, and the shape of the arc flow equalizing plate is an arc umbrella-shaped structure extending upward, that is, a first arc is formed by extending upward from a point on the inner wall of the upper head to a point on the vertical center line of the upper head, and then the first arc is rotated 360° around the vertical center line of the upper head to form a shape. Viewed along the longitudinal section of the vertical center line of the upper head, the section of the arc flow equalizing plate is an arc-shaped structure with a first curvature. The shape of the upper tube sheet is an arc-shaped umbrella-shaped structure extending downward, that is, a second arc is formed by extending downward from a point on the inner wall of the shell to a point on the vertical center line of the shell, and then the second arc is rotated 360° around the vertical center line of the shell to form a shape. Viewed along the longitudinal section of the vertical center line of the shell, the section of the upper tube sheet is an arc-shaped structure with a second curvature.

[0020] The present invention adopts an upwardly protruding arc flow equalizing plate and a downwardly protruding arc tube sheet, so that the fluid entering from the tube inlet first passes through the arc flow equalizing plate for flow equalization, and the arc flow equalizing plate allows more fluid to flow into the heat exchange tube through the edge of the flow equalizing plate close to the inner wall of the head, so that the fluid is evenly distributed. Then, the fluid entering the upper tube sheet is evenly distributed again through the downwardly protruding structure of the upper tube sheet to avoid excessive fluid from entering the heat exchange tube at the edge, ensuring that the middle heat exchange tube can distribute the fluid, so that the synergistic effect of the flow equalizing plate and the tube sheet makes the fluid distribution in the heat exchange tube more even, avoiding excessive fluid in the center part, and ensuring that there is too much fluid in the edge heat exchange tube close to the inner wall of the head, so that the fluid is evenly exchanged on the whole, and the purpose of enhancing heat transfer is further achieved.

[0021] As a preference, Figure 1 As shown, the arc of the arc flow equalizing plate is a first arc, which is less than 90°, and the arc of the upper tube plate is a second arc, which is less than 90°. By setting the arc to be less than 90°, the flow direction of the above-mentioned fluid is slow, and the fluid is prevented from flowing quickly and accumulating at the bottom, causing uneven distribution. By setting the above-mentioned arc, the fluid can be distributed more evenly.

[0022] The second curvature is smaller than the first curvature. The second curvature is 15-30° smaller than the first curvature. By setting the size of the above curvature, the fluid distribution can be made more uniform. Because the curvature of the upper uniform plate is large, it is more inclined and the flow speed is fast. During operation, part of the fluid may quickly enter the edge and enter the lower heat exchange tube through the hole in the edge. Then, by setting a slower inclination curvature at the bottom, more fluid can be prevented from entering the bottom of the tube sheet. The above curvature can make the fluid distribution more uniform.

[0023] Preferably, the arc flow equalizing plate is manufactured in an integrated manner, which can make the structure more solid and convenient to manufacture.

[0024] Preferably, the upper tube plate is manufactured in an integrated manner, which can make the structure stronger and facilitate manufacturing.

[0025] Preferably, the distance between the highest point of the arc flow equalizing plate and the lowest point of the upper tube plate is 0.38-0.62 times the height of the upper head and 0.92-1.08 times the diameter of the upper head.

[0026] The above-mentioned size ratio is obtained after a lot of experimental research. If the distance is too large, it will cause a waste of material space. If the distance is too small, the fluid flow space will be too small, and there will be no time for full mixing and flow, resulting in poor flow balancing effect. Therefore, the above-mentioned optimization results were obtained after a lot of research.

[0027] Preferably, the second arc ranges from 40 to 75 degrees, and the first arc ranges from 70 to 88 degrees. The above arcs are also optimized structures after a large number of experiments, which can achieve the best diversion effect.

[0028] Preferably, a shell-side inlet 10 and an outlet 11 are arranged on the shell, wherein the shell-side inlet is arranged at the lower part of the shell, and the shell-side outlet is arranged at the upper part of the shell.

[0029] Preferably, baffles 12 are provided in the shell, and the baffles are arranged at intervals on the left and right sides of the shell.

[0030] The fluid in the heat exchanger moves in countercurrent. As an improvement, the spacing of the baffle group increases continuously from the tube inlet to the middle of the tube along the flow direction of the fluid in the tube. Then, the spacing of the baffle group decreases continuously from the middle of the tube to the tube outlet. Because in the countercurrent process, the heat exchange of the shell and tube per unit length along the flow process of the fluid is relatively uniform, so that the overall heat exchange effect is the best. However, it was found in experiments and simulations that the heat exchange in the middle is significantly greater than the heat exchange at the tube inlet and outlet. Therefore, by changing the spacing between the baffles, the heat exchange area between the tube fluid and the shell fluid in the baffle also changes. Therefore, the uneven heat exchange is compensated by the change in area, thereby further improving the heat exchange efficiency.

[0031] As an improvement, along the flow direction of the fluid in the tube, from the tube entrance to the middle of the tube, the distance between the baffles increases. Then, from the middle of the tube to the tube exit, the distance between the baffles decreases. The above changes in the range can make the heat transfer per unit length of the entire fluid movement more uniform, further improving the heat transfer efficiency.

[0032] As an improvement, the flow balancing holes on the arc flow balancing plate 9 are arranged unevenly. From the center of the flow balancing plate to the edge of the flow balancing plate, that is, Figure 1The distribution density of the flow equalizing holes increases from the highest point of the flow equalizing plate to the lowest point of the flow equalizing plate. The heat exchange tube holes of the upper tube plate are also unevenly arranged. From the edge to the center of the upper tube plate, that is, Figure 1 The distribution density of the equalizing holes increases from the highest point to the lowest position of the middle and upper tube plates. The increase in the distribution density of the equalizing plates can make the fluid distributed to the edges as much as possible, while the distribution of the upper tube plates makes the fluid distributed in the middle as much as possible. Through the above two repeated and continuous remixing and distribution processes, the fluid distribution can be made more uniform.

[0033] As an improvement, the distribution density of the flow equalizing holes increases continuously from the center to the edge of the flow equalizing plate. Figure 1 From the highest point to the lowest position of the middle and upper tube plate, the distribution density of the flow balancing holes increases continuously. Through the above-mentioned flow balancing holes and the tube hole distribution density amplitude change setting, the two fluids can be further distributed more evenly.

[0034] As an improvement, from the center of the current balancing plate to the edge of the current balancing plate, that is, Figure 1 From the highest point of the flow plate to the lowest point of the flow plate, the diameter of the flow holes increases continuously. Figure 1 The diameter of the flow equalizing hole increases from the highest point to the lowest position of the middle and upper tube plate. By increasing the diameter of the flow equalizing plate, the fluid can be distributed to the edges as much as possible, while the distribution of the upper tube plate makes the fluid distributed in the middle as much as possible. Through the above two repeated and continuous re-mixing and distribution processes, the fluid distribution can be made more uniform.

[0035] As an improvement, the diameter of the flow equalizing hole increases continuously from the center to the edge of the flow equalizing plate. Figure 1 From the highest point to the lowest position of the middle and upper tube plate, the diameter of the flow-equalizing holes increases continuously. Through the above-mentioned flow-equalizing holes and the setting of the diameter amplitude variation of the tube hole distribution, the two fluids can be further distributed more evenly.

[0036] Although the present invention has been disclosed as above with preferred embodiments, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A vertical heat exchanger with an arc flow equalizing plate, the heat exchanger comprising a shell, an upper head and a lower head, the upper head, the shell and the lower head are connected in sequence, a tube-side inlet is arranged at the middle position of the top of the upper head, and a tube-side outlet is arranged at the lower head, the heat exchange tube is arranged in the shell, the heat exchange tube is fixedly connected to the upper tube sheet and the lower tube sheet, the upper tube sheet is arranged between the upper head and the shell, and the lower tube sheet is arranged between the lower head and the shell, the fluid enters from the tube-side inlet, flows through the heat exchange tube, exchanges heat with the fluid in the shell, and then enters the lower head and flows out from the tube-side outlet; characterized in that An arc flow equalizing plate is arranged in the upper head, and the arc flow equalizing plate is bent upward from the inner wall of the upper head. The highest point of the arc flow equalizing plate is located at the center point of the cross section of the upper head, and the arc flow equalizing plate is provided with flow equalizing holes which pass through from top to bottom; the upper tube plate is an arc plate bent downward from the inner wall of the shell, and the upper tube plate and the arc flow equalizing plate are symmetrically arranged along the vertical center line of the upper head, and the upper tube plate is provided with tube holes for the heat exchange tubes to pass through.

2. The heat exchanger according to claim 1, characterized in that The arc angle of the arc flow equalizing plate is a first arc angle, which is less than 90°, and the arc angle of the upper tube plate is a second arc angle, which is less than 90°.

3. The heat exchanger according to claim 2, characterized in that The second arc is smaller than the first arc.

4. The heat exchanger according to claim 3, characterized in that The second arc is 15-30° smaller than the first arc.

5. The heat exchanger according to claim 1, characterized in that The arc flow equalizing plate is manufactured in an integrated manner.

6. The heat exchanger according to claim 1, characterized in that The upper tube plate is manufactured in one piece.

7. The heat exchanger according to claim 1, characterized in that: The distance between the highest point of the arc flow equalizing plate and the lowest point of the upper tube plate is 0.38-0.62 times the height of the upper head and 0.92-1.08 times the diameter of the upper head.

8. The heat exchanger according to claim 1, characterized in that The second arc ranges from 40 to 75 degrees, and the first arc ranges from 70 to 88 degrees.

9. The heat exchanger according to claim 1, characterized in that: The shell is provided with a shell-side inlet and an outlet, wherein the shell-side inlet is arranged at the lower part of the shell, and the shell-side outlet is arranged at the upper part of the shell.

10. The heat exchanger according to claim 8, characterized in that Baffles are arranged in the shell, and the baffles are arranged at intervals on the left and right sides.

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