Arc-shaped flow-distributing plate vertical heat exchanger

Abstract

The application provides a circular arc flow distribution plate vertical heat exchanger, wherein a circular arc flow distribution plate is arranged in the upper head, the circular arc flow distribution plate is curved upward from the inner wall of the upper head, the highest point of the circular arc flow distribution plate is located on the center point of the cross section of the upper head, and flow distribution holes penetrating through the circular arc flow distribution plate are arranged on the circular arc flow distribution plate; the upper tube plate is a circular arc plate curved downward from the inner wall of the shell, the upper tube plate and the circular arc flow distribution plate are symmetrically arranged along the vertical center line of the upper head, and tube holes through which heat exchange tubes pass are arranged on the upper tube plate. The upward extending circular arc flow distribution plate and the downward extending upper tube plate can uniformly distribute the fluid entering the shell pass, and improve the overall heat exchange effect.

Description

Technical Field

[0001] This invention relates to a shell-and-tube heat exchanger, and more particularly to a vertical heat exchanger with an arc-shaped flow equalization plate. Background Technology

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

[0003] In practical applications, heat exchange tubes directly facing the inlet receive more fluid, while those farther from the inlet receive less. Heat exchange tubes positioned higher receive even less fluid, especially in heat exchangers with a large number of tubes. This uneven fluid distribution and the inability of fluid to enter the heat exchange tubes simultaneously affect heat exchange efficiency. Therefore, it is essential to develop a new type of shell-and-tube heat exchanger.

[0004] Traditional baffle heat exchangers still employ flow equalization methods to ensure uniform fluid distribution. For example, patent application CN204880602U uses a plate-type flow equalization device. When setting the guide plates, the distance between the flow channels near the center of the head is small, while the distance between the flow channels near the two ends of the head is large, arranged symmetrically on both sides. This guide plate arrangement can significantly improve the uniformity of air flow distribution in each flow channel of the heat exchanger. The flow equalization device in patent application CN207703067U is a conical block structure located inside the upper head, with gaps between the flow equalization device and the upper head, upper cover plate, and block graphite. The top of the flow equalization device corresponds to the inlet, and the bottom corresponds to the block graphite.

[0005] The aforementioned structures all employ a single flow equalization mode, resulting in complex structures and limited flow equalization performance, leading to poor flow equalization efficiency. To address these shortcomings, a simpler shell-and-tube heat exchanger combining a flow equalization plate and a tube sheet is developed. This design achieves more uniform fluid distribution and improves heat exchange efficiency, which is of great significance for industrial production and energy conservation and emission reduction. Summary of the Invention

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A vertical heat exchanger with an arc-shaped flow equalization plate includes a shell, an upper head, and a lower head, which are connected sequentially. A tube inlet is located at the center of the top of the upper head, and a tube outlet is located on the lower head. The heat exchange tubes are disposed within the shell and are fixedly connected to an upper tube sheet and a lower tube sheet. The upper tube sheet is positioned between the upper head and the shell, and the lower tube sheet is positioned between the lower head and the shell. Fluid enters from the tube inlet, flows through the heat exchange tubes, and interacts with the fluid inside the shell. Heat exchange occurs, and the heat flows into the lower head, exiting from the tube side outlet. An arc-shaped flow equalization plate is installed inside the upper head, curving upwards from the inner wall of the upper head. The highest point of the arc-shaped flow equalization plate is located at the center of the cross-section of the upper head. Flow equalization holes are provided on the arc-shaped flow equalization plate, running vertically through it. The upper tube sheet is an arc-shaped plate curving downwards from the inner wall of the shell. The upper tube sheet and the arc-shaped flow equalization plate are symmetrically arranged along the vertical centerline of the upper head. Tube holes are provided on the upper tube sheet through which the heat exchange tubes pass.

[0008] The arc radius of the flow equalization plate is the first arc radius, which is less than 90°, and the arc radius of the upper tube sheet is the second arc radius, which is less than 90°.

[0009] The second radian is smaller than the first radian.

[0010] The second radian is 15-30° smaller than the first radian.

[0011] The arc-shaped flow equalizer is manufactured as a single piece.

[0012] The upper tube sheet is manufactured as a single unit.

[0013] The distance between the highest point of the arc flow equalization plate and the lowest point of the upper tube sheet is 0.38-0.62 times the height of the upper head and 0.92-1.08 times the diameter of the upper head.

[0014] The second radian range is between 100-110°, and the first radian range is between 125-155°.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention employs an upwardly protruding arc-shaped flow equalization plate and a downwardly protruding arc-shaped tube sheet. Fluid entering from the tube-side inlet first undergoes flow equalization through the arc-shaped flow equalization plate. The plate allows more fluid to flow into the heat exchange tubes near the inner wall of the end cap, resulting in uniform fluid distribution. The fluid entering the upper tube sheet is then further evenly distributed through the downward protrusions of the upper tube sheet, preventing excessive fluid from entering the edge heat exchange tubes and ensuring sufficient fluid distribution in the central heat exchange tubes. Through the synergistic effect of the flow equalization plate and tube sheet, and the repeated reciprocating motion of the fluid, the distribution within the heat exchange tubes becomes more uniform. This avoids excessive fluid in the central area while ensuring sufficient fluid in the edge heat exchange tubes near the inner wall of the end cap, resulting in overall uniform heat transfer and further enhancing heat transfer. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the heat exchanger of the present invention. Detailed Implementation

[0018] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] A vertical heat exchanger with an arc-shaped flow equalization plate, such as Figure 1 As shown, the heat exchanger includes a shell 1, an upper head 2, and a lower head 3, which are connected sequentially from top to bottom. A tube-side inlet 4 is located at the middle of the top of the upper head 2, and a tube-side outlet 5 is located on the lower head 3. The heat exchange tubes 6 are disposed inside the shell 1 and are fixedly connected to an upper tube sheet 7 and a lower tube sheet 8. The upper tube sheet 7 is disposed between the upper head 2 and the shell 1, and the lower tube sheet 8 is disposed between the lower head 3 and the shell 1. The fluid enters from the tube-side inlet 4, flows through the heat exchange tubes 6, exchanges heat with the fluid inside the shell 1, and then enters the lower head 3 and flows out from the tube-side outlet 5.

[0020] As an improvement, the upper head and shell have a square cross-section. As an improvement, an arc-shaped flow equalization plate 9 is provided inside the upper head 2. This arc-shaped flow equalization plate bends upwards from both sides of the inner wall of the upper head, with its highest point located at the center of the cross-section of the upper head. The arc-shaped flow equalization plate has vertically penetrating flow equalization holes. The upper tube sheet 7 is an arc-shaped plate bending downwards from the inner wall of the shell. The upper tube sheet and the arc-shaped flow equalization plate are symmetrically arranged along the vertical centerline of the upper head. The upper tube sheet has pipe holes through which heat exchange tubes 6 pass. The lowest point of the upper tube sheet is located at the center of the shell cross-section.

[0021] As an improvement, the upper head and shell have circular cross-sections. The arc-shaped flow equalization plate is an upward-extending arc-shaped umbrella structure, formed by extending upwards from a point on the inner wall of the upper head to a point on the vertical center line of the upper head, creating a first arc, which then rotates 360° around the vertical center line of the upper head. Viewed longitudinally along the vertical center line of the upper head, the arc-shaped flow equalization plate has an arc-shaped cross-section with a first curvature. The upper tube sheet has a downward-extending arc-shaped umbrella structure, formed by extending downwards from a point on the inner wall of the shell to a point on the vertical center line of the shell, creating a second arc, which then rotates 360° around the vertical center line of the shell. Viewed longitudinally along the vertical center line of the shell, the upper tube sheet has an arc-shaped cross-section with a second curvature.

[0022] This invention employs an upwardly protruding arc-shaped flow equalization plate and a downwardly protruding arc-shaped tube sheet. Fluid entering from the tube-side inlet first undergoes flow equalization through the arc-shaped flow equalization plate. The plate allows more fluid to flow into the heat exchange tubes through the edge near the inner wall of the end cap, resulting in uniform fluid distribution. Then, the fluid entering the upper tube sheet is further evenly distributed through the downward protrusions of the upper tube sheet, preventing excessive fluid from entering the edge heat exchange tubes and ensuring sufficient fluid distribution in the central heat exchange tubes. Through the synergistic effect of the flow equalization plate and the tube sheet, the fluid distribution within the heat exchange tubes becomes more uniform, avoiding excessive fluid in the central area while ensuring sufficient fluid in the edge heat exchange tubes near the inner wall of the end cap. This results in overall uniform heat transfer, further enhancing the heat transfer effect.

[0023] As a preferred option, such as Figure 1 As shown, the arc radius of the circular flow equalization plate is the first arc radius, less than 90°, and the arc radius of the upper tube plate is the second arc radius, also less than 90°. By setting the arc radius to less than 90°, the flow direction of the fluid is slowed down, preventing the fluid from flowing rapidly and accumulating at the bottom, thus avoiding uneven distribution. Setting the arc radius allows for a more uniform fluid distribution.

[0024] The second curvature is smaller than the first curvature. The second curvature is 15-30° smaller than the first curvature. By setting the curvature of the upper uniform plate, the fluid distribution can be made more uniform. Because the upper uniform plate has a larger curvature, it is more inclined, resulting in a faster flow velocity. During operation, some fluid may quickly enter the edge and flow through the holes in the edge into the lower heat exchange tubes. Then, by setting a slightly gentler incline at the bottom, more fluid can be prevented from entering the bottom of the tube sheet. The aforementioned curvature allows for a more uniform fluid distribution.

[0025] As a preferred option, the arc-shaped flow equalizer is manufactured as a single piece. This makes the structure more robust and easier to manufacture.

[0026] As a preferred option, the upper tube sheet is manufactured as a single piece. This results in a more robust structure and facilitates manufacturing.

[0027] Preferably, the distance between the highest point of the arc flow equalization plate and the lowest point of the upper tube sheet is 0.38-0.62 times the height of the upper head and 0.92-1.08 times the diameter of the upper head.

[0028] The aforementioned size ratios were derived through extensive experimental research. If the distance is too large, it results in wasted material space; if the distance is too small, the fluid flow space becomes too limited, preventing sufficient mixing and leading to poor flow uniformity. Therefore, the above optimized results were obtained through extensive research.

[0029] Preferably, the second arc ranges from 40 to 75 degrees, and the first arc ranges from 70 to 88 degrees. These arcs are also the result of extensive experimental optimization, ensuring optimal flow distribution.

[0030] Preferably, the shell is provided with a shell-side inlet 10 and an outlet 11, with the shell-side inlet located at the lower part of the shell and the shell-side outlet located at the upper part of the shell.

[0031] Preferably, baffles 12 are provided inside the housing, with the baffles spaced apart on the left and right sides of the housing.

[0032] The fluid inside the heat exchanger flows counter-currently. As an improvement, the spacing of the baffle assemblies increases continuously from the tube inlet to the middle of the tube side along the fluid flow direction. Then, from the middle of the tube side to the tube outlet, the spacing decreases continuously. This is because, during counter-current flow, the heat exchange per unit length between the shell and tube sides is relatively uniform, resulting in the best overall heat exchange effect. However, experiments and simulations have shown that the heat exchange in the middle is significantly greater than that at the tube inlet and outlet. Therefore, by changing the baffle spacing, the heat exchange area between the tube-side and shell-side fluids within the baffles also changes. This area variation compensates for the uneven heat exchange, thereby further improving heat exchange efficiency.

[0033] As an improvement, along the flow direction of the fluid within the tube, the spacing of the baffle assembly increases progressively from the tube inlet to the middle of the tube. Then, from the middle of the tube to the tube outlet, the spacing of the baffle assembly decreases progressively. These variations in spacing make the heat transfer per unit length of the entire fluid flow more uniform, further improving heat transfer efficiency.

[0034] As an improvement, the flow equalization holes on the arc-shaped flow equalization plate 9 are arranged non-uniformly. From the center of the flow equalization plate to its edge, i.e. Figure 1From the highest point to the lowest point of the flow equalization plate, the distribution density of the flow equalization holes continuously increases. The heat exchange tube holes in the upper tube sheet are also unevenly distributed. From the edge to the center of the upper tube sheet, i.e. Figure 1 From the highest point to the lowest position of the upper tube sheet, the distribution density of the flow equalization orifices continuously increases. This increased distribution density through the flow equalization plate allows the fluid to be distributed as far towards the edges as possible, while the distribution on the upper tube sheet further concentrates the fluid in the center. Through these two repeated processes of remixing and redistribution, the fluid distribution becomes more uniform.

[0035] As an improvement, the distribution density of the flow equalization holes increases progressively from the center to the edge of the flow equalization plate. From the edge to the center of the upper tube sheet, i.e. Figure 1 From the highest point to the lowest position of the upper tube sheet, the distribution density of the flow equalization orifices continuously increases. By setting the aforementioned variations in the distribution density of the flow equalization orifices and tube holes, the distribution of the two fluids can be further made more uniform.

[0036] As an improvement, the distance from the center of the flow equalization plate to its edge, i.e. Figure 1 From the highest point to the lowest point of the flow equalization plate, the diameter of the flow equalization orifices continuously increases. From the edge of the upper tube sheet to the center, i.e. Figure 1 From the highest point to the lowest position of the upper tube sheet, the diameter of the flow equalization orifice continuously increases. This increase in the diameter of the flow equalization plate allows the fluid to be distributed as far towards the edges as possible, while the distribution on the upper tube sheet further concentrates the fluid in the center. Through these two repeated processes of remixing and redistribution, the fluid distribution becomes more uniform.

[0037] As an improvement, the diameter of the flow equalization orifice increases progressively from the center to the edge of the flow equalization plate. From the edge to the center of the upper tube sheet, i.e. Figure 1 From the highest point to the lowest position of the upper tube sheet, the diameter of the flow equalization orifice continuously increases. Through the aforementioned settings of the flow equalization orifice and the varying orifice diameter, the distribution of the two fluids can be further made more uniform.

[0038] While the present invention has been disclosed above with reference to preferred embodiments, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A circular arc flow uniforming plate vertical heat exchanger, the heat exchanger comprising a shell, an upper head and a lower head, the upper head, the shell and the lower head being connected in sequence, a tube side inlet being arranged at the middle position of the top of the upper head, a tube side outlet being arranged on the lower head, heat exchange tubes being arranged in the shell, the heat exchange tubes being fixedly connected to an upper tube plate and a lower tube plate, the upper tube plate being arranged between the upper head and the shell, the lower tube plate being arranged between the lower head and the shell, fluid entering from the tube side inlet, flowing through the heat exchange tubes, exchanging heat with the fluid in the shell, then entering the lower head and flowing out from the tube side outlet; characterized in that, The baffle is arranged in the shell, and the baffle is arranged at intervals between the left side and the right side of the shell; the fluid in the heat exchanger is countercurrent motion, along the flow direction of the fluid in the tube, from the tube inlet to the middle position of the tube, the distance between the baffles is constantly increasing; then from the middle position of the tube to the tube outlet, the distance between the baffles is constantly decreasing; the arc flow distribution plate is arranged in the upper head, the arc flow distribution plate is curved upward from the inner wall of the upper head, the highest point of the arc flow distribution plate is located on the center point of the cross section of the upper head, and the arc flow distribution plate is provided with flow distribution holes penetrating upward and downward; the upper tube plate is a circular arc plate curved downward from the inner wall of the shell, the upper tube plate and the arc flow distribution plate are symmetrically arranged along the vertical center line of the upper head, and the upper tube plate is provided with tube holes through which heat exchange tubes pass.

2. The heat exchanger of claim 1, wherein The arc radian of the arc flow distribution plate is a first radian, which is less than 90°, and the arc radian of the upper tube plate is a second radian, which is less than 90°.

3. The heat exchanger of claim 2, wherein The second radian is less than the first radian.

4. The heat exchanger of claim 3, wherein The second radian is less than the first radian by 15-30°.

5. The heat exchanger of claim 1, wherein The arc flow distribution plate is integrally manufactured.

6. The heat exchanger of claim 1, wherein The upper tube plate is integrally manufactured.

7. The heat exchanger of claim 1, wherein The distance between the highest point of the arc flow distribution 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 of claim 1, wherein The second radian ranges from 40-75°, and the first radian ranges from 70-88°.

9. The heat exchanger of claim 1, wherein The shell is provided with a shell inlet and an outlet, the shell inlet is arranged at the lower part of the shell, and the shell outlet is arranged at the upper part of the shell.

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