Shell-and-tube heat exchanger with fan-shaped baffle plate group

Abstract

The invention provides a fan-shaped baffle plate group shell-and-tube cooler which is characterized in that a baffle plate group comprises upper and lower baffle plates arranged in the vertical direction and left and right baffle plates arranged in the left and right direction, and the upper and lower baffle plates and the left and right baffle plates are spaced by a certain distance; the upper and lower baffle plates comprise two fan-shaped baffle plates which are symmetrically arranged up and down along the central line of the tube shell, and the left and right baffle plates comprise fan-shaped baffle plates which are symmetrically arranged left and right along the central line of the tube shell; in the flowing direction of fluid in the shell pass, the proportion of the area of the upper baffle plate and the area of the lower baffle plate in the baffle plate set to the area of the left baffle plate and the area of the right baffle plate in the baffle plate set is gradually increased firstly and then gradually decreased after reaching a certain position. According to different positions, heat exchange at different positions is strengthened, and the purpose of strengthening heat transfer is further achieved.

Description

Technical Field

[0001] The invention relates to a shell and tube heat exchanger, in particular to a shell and tube cooler with a fan-shaped baffle group. 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] Shell and tube heat exchangers are still the mainstream type of heat exchange equipment due to their simple structure and high pressure resistance. Although the commonly used bow-shaped baffles are simple to manufacture, they have flow dead zones, large flow resistance, and large spans of tube bundle support at the notch, which easily induce vibration damage. Therefore, many new tube bundle support schemes have been spawned, and spiral baffles are one of them. Theoretically, spiral baffles are curved surfaces and difficult to make. At present, there are improved schemes for 1 / 4 elliptical / sector-shaped spiral baffles. Each layer of baffles is composed of 4 pieces of 1 / 4 elliptical / sector-shaped baffles, which are connected head to tail to form a shell-side spiral channel. Since shell and tube heat exchangers use a large number of tube bundles arranged in the most compact equilateral triangle, this makes it difficult to mark and position the inclined tube holes on the 1 / 4 elliptical / sector-shaped baffles, affecting the popularization and application of this type of baffles.

[0004] The traditional shell channel is composed of fan-shaped baffles. Each fan-shaped baffle is at a certain angle to the axis of the shell. They are arranged in sequence from the front to the back of the shell. A "Z"-shaped space is formed between the fan-shaped baffles in two adjacent quadrants, and there is a certain gap (2 to 3 mm) between the baffles and the shell. The baffles of this structure often cause the flowing medium to form a short-circuit shunt phenomenon between the inner wall of the shell and the baffle boundary. The short-circuit shunt reduces the flow rate of the spiral channel medium and weakens the heat exchange. It also causes the shell-side fluid to locally scour the baffles, causing the metal baffles to rust for a long time and affecting the water quality. In addition, the baffles of this structure will cause the shell-side fluid to generate vortices at local locations, seriously affecting the heat exchange effect of the heat exchanger.

[0005] However, the traditional baffle heat exchanger also has some shortcomings, such as large flow resistance, a large number of flow dead zones, low heat transfer efficiency, etc. Therefore, under the new energy conservation and emission reduction situation, its development is greatly restricted. Therefore, in view of these shortcomings, a baffle and shell and tube heat exchanger with simple structure and mature technology is developed to effectively improve its heat exchange area and heat exchange efficiency, which is of great significance to industrial production and energy conservation and emission reduction. Summary of the invention

[0006] In order to overcome the defects and shortcomings in the prior art, the present invention provides a shell and tube heat exchanger with a new layout of baffles, which can improve the convective heat transfer coefficient of the shell side of the heat exchanger, thereby effectively improving the heat transfer efficiency.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] A shell and tube cooler with a fan-shaped baffle group, the shell and tube heat exchanger comprises a tube shell, a heat exchange tube, a shell-side inlet pipe and a shell-side outlet pipe; the shell-side inlet pipe and the shell-side outlet pipe are respectively located at two ends of the heat exchanger; the heat exchange tube is arranged in the tube shell, and the heat exchange tube is fixedly connected to the tube sheet; it is characterized in that a plurality of fan-shaped baffle groups are arranged in the tube shell, the baffle group comprises upper and lower baffles arranged in the up and down direction and left and right baffles arranged in the left and right direction, and the upper and lower baffles and the left and right baffles are spaced a certain distance apart; the upper and lower baffles comprise two fan-shaped baffles symmetrically arranged up and down along the center line of the tube shell, and the left and right baffles comprise fan-shaped baffles symmetrically arranged left and right along the center line of the tube shell; along the flow direction of the fluid in the shell, the area ratio of the upper and lower baffles in the baffle group to the area ratio of the left and right baffles gradually increases first, and then gradually decreases after reaching a certain position.

[0009] As an improvement, the certain position is a middle position of the tube shell.

[0010] As an improvement, along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles gradually increases.

[0011] As an improvement, along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles gradually decreases to a smaller and smaller extent.

[0012] As an improvement, the fan-shaped angle of the baffle group is 170-190°.

[0013] As an improvement, the fan-shaped angle of the baffle group is 170-190°.

[0014] As an improvement, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles is 0.9-1.2.

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

[0016] 1) The present invention changes the area ratio of the upper and lower baffles to the left and right baffles in the baffle group along the flow direction of the fluid, so that the fluid in the shell gradually moves more and more toward the left and right directions, that is, the middle position of the upper and lower directions, so that the heat exchange tubes at the left and right positions strengthen the heat exchange when they reach the middle position in the length direction of the shell, and the heat exchange tubes at the upper and lower positions strengthen the heat exchange when they meet the two ends of the shell. According to different positions, the heat exchange at different positions is strengthened, which changes the single heat exchange mode in the past, strengthens the heat exchange efficiency at different positions, makes the heat exchange uniform on the whole, and further achieves the purpose of strengthening heat transfer.

[0017] 2) By changing the spacing between the baffles, the heat exchange area between the tube-side fluid and the shell-side fluid in the baffles also changes. Therefore, the uneven heat exchange amount is compensated by the change in area, thereby further improving the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the heat exchange tube structure of the shell and tube heat exchanger of the baffle group provided in the present invention.

[0019] Figure 2 is a schematic top view of the baffle assembly of the present invention;

[0020] Figure 3 It is a schematic diagram of the upper and lower baffles of the present invention;

[0021] Figure 4 It is a schematic diagram of the left and right baffles of the present invention;

[0022] Figure 5 It is a schematic diagram of the control structure of the present invention. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0024] In this article, unless otherwise specified, “ / ” represents division, and “×” and “*” represent multiplication.

[0025] A shell and tube heat exchanger (cooler), such as Figure 1As shown, the shell and tube heat exchanger is arranged horizontally, including a tube shell 1, a heat exchange tube 8, a shell-side inlet pipe 2 and a shell-side outlet pipe 3; the shell-side inlet pipe 2 and the shell-side outlet pipe 3 are respectively located on the left side of the upper end and the right side of the lower end of the tube shell 1; the heat exchange tube 8 is arranged in the tube shell 1, and the heat exchange tube is fixedly connected to the left tube sheet and the right tube sheet; the front end of the left tube sheet is connected to the left header 4, and the rear end of the right tube sheet is connected to the right header 5; the tube-side outlet pipe 10 is arranged on the left header 4; the tube-side inlet pipe 9 is arranged on the right header 5; the shell-side inlet pipe 2 and the shell-side outlet pipe 3 are both arranged on the tube shell 1; the gas enters from the shell-side inlet pipe 2, exchanges heat through the heat exchange tubes, and exits from the shell-side outlet pipe 3.

[0026] As an improvement, the heat exchanger is an injection water cooling device, the tube side contains injection water, the shell side contains cold water, and the injection water is cooled by the cold water.

[0027] like Figure 2 As shown, a plurality of fan-shaped baffle groups 6 are arranged in the tube shell, and the fan-shaped baffle group includes upper and lower baffles 61 arranged in the vertical direction and left and right baffles 62 arranged in the left and right direction, and the upper and lower baffles 61 and the left and right baffles 62 are spaced a certain distance apart; the upper and lower baffles include two fan-shaped baffles 61 symmetrically arranged up and down along the center line of the tube shell, and the left and right baffles include fan-shaped baffles 62 symmetrically arranged left and right along the center line of the tube shell; along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles in the baffle group to the area of ​​the left and right baffles gradually increases at first, and then gradually decreases after reaching a certain position.

[0028] During the research process, it was found that the heat exchange of the baffles of the traditional heat exchanger was uneven in the cross section in the flow direction, with good heat exchange effect on the left and right sides of the inlet and outlet, and good heat exchange effect in the middle upper and lower positions. In the present invention, along the flow direction of the fluid, the area ratio of the upper and lower baffles in the baffle group to the area ratio of the left and right baffles first gradually increases, and then gradually decreases, so that the fluid in the shell gradually moves closer to the left and right sides in the middle, so that the heat exchange tubes on the left and right sides of the shell at the center of the fluid strengthen the heat exchange, and then the heat exchange tubes at the upper and lower positions of the shell inlet and outlet at the front and rear ends strengthen the heat exchange. According to different positions, the heat exchange at different positions is strengthened, which changes the previous single heat exchange mode, strengthens the heat exchange efficiency at different positions, makes the heat exchange uniform on the whole, and further achieves the purpose of strengthening heat transfer.

[0029] The above-mentioned area is the area projected onto the cross section of the shell, or the area projected onto the vertical plane.

[0030] Preferably, at the center of the fluid flow direction in the shell, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles reaches a maximum.

[0031] As an improvement, the distance between the upper and lower baffles 61 and the left and right baffles 62 is 0.6-0.9 times the diameter of the tube shell, preferably 0.8 times.

[0032] As an improvement, the certain position is a middle position of the tube shell.

[0033] As an improvement, along the flow direction of the fluid in the shell side, the area ratio of the upper and lower baffles to the left and right baffles is gradually increased. Through the above-mentioned change in amplitude, the overall heat exchange can be further uniform, further achieving the purpose of enhancing heat transfer.

[0034] As an improvement, along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles gradually decreases. Through the above-mentioned change in amplitude, the overall heat exchange can be further uniform, further achieving the purpose of enhancing heat transfer.

[0035] As an improvement, the sum of the fan-shaped angles of the baffle group is 170-190°. Figure 2 The sum of the angles of the four fan-shaped baffles is 170-190°.

[0036] As an improvement, the sum of the fan-shaped angles of the baffle group is 180°.

[0037] As an improvement, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles is 0.9-1.2.

[0038] By optimizing the above parameters, the heat exchange efficiency can be optimized.

[0039] As an improvement, the shell side and the tube side flow in countercurrent, and along the flow direction of the fluid in the tube side, the spacing of the baffle group increases continuously from the tube side inlet to the middle of the tube side. Then from the middle of the tube side to the tube side outlet, the spacing of the baffle group decreases continuously. Because in the countercurrent process, the heat exchange of the shell side and the tube side 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 side inlet and outlet. Therefore, by changing the spacing between the baffles, the heat exchange area between the tube side fluid and the shell side 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.

[0040] 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.

[0041] As an improvement, the heat exchanger further comprises a control system, which controls the flow rate of the heat source entering the shell side of the heat exchanger according to the outlet temperature of the tube side.

[0042] As an improvement, the control system includes: a temperature sensor 13, a flow controller 14 and a central controller 12, the flow controller controls the flow rate of the heat source entering the heat exchanger; the temperature sensor is used to measure the outlet temperature of the cold source of the tube side, when the cold source temperature is lower than the first temperature, the flow controller is fully opened, when the cold source outlet temperature reaches the first temperature, the central controller controls the flow controller to reach a first flow rate, the first flow rate is lower than the fully opened flow rate, when the cold source outlet temperature reaches a second temperature higher than the first temperature, the central controller controls the flow rate to reach a second flow rate lower than the first flow rate controller, when the cold source outlet temperature reaches a third temperature higher than the second temperature, the central controller controls the flow controller to reach a third flow rate lower than the second flow rate, when the cold source outlet temperature reaches a fourth temperature higher than the third temperature, the central controller controls the flow controller to reach a fourth flow rate lower than the third flow rate; when the cold source outlet temperature reaches a fifth temperature higher than the fourth temperature, the central controller closes the flow controller to prevent water from entering the heat exchanger.

[0043] The fifth temperature is a temperature exceeding the upper limit of the preset data, and the first temperature is a temperature below the lower limit of the preset data. Through the above settings, the heat exchange amount of the heat exchanger can be controlled according to the temperature, thereby achieving the effect of saving heat source.

[0044] As an improvement, the control system may be a single chip microcomputer, and a control panel may be provided. The control panel may be provided at the upper part or the lower part of the heat exchanger, or may be provided on the pipe entering the heat exchanger.

[0045] As an improvement, the vertices (centers of circles) of the upper and lower baffles and the left and right baffles are located on the center line of the tube shell, that is, the line formed by the center points of the cross section.

[0046] Under normal circumstances, the baffles are arranged in a vertical direction. As an improvement, the upper and lower baffles and the left and right baffles are rotated around their respective baffle center lines at a certain angle, that is, the baffles are tilted at a certain angle to the vertical plane. The baffle center line is the line connecting the vertex (center of the circle) of the fan and the midpoint of the arc of the fan. By rotating at a certain angle, the fluid can form a spiral baffle effect, thereby improving the heat transfer coefficient.

[0047] As an improvement, the rotation angles of the symmetrically arranged upper baffle and lower baffle are opposite, and the rotation angles of the symmetrically arranged left baffle and right baffle are opposite. For example, when viewed from above, the upper baffle rotates clockwise, and the lower baffle rotates counterclockwise. Or when viewed from the horizontal direction, the left baffle rotates clockwise, and the right baffle rotates counterclockwise.

[0048] As an improvement, along the flow direction of the fluid, the angles at which the upper and lower baffles rotate around their respective baffle center lines first become smaller and smaller, and then become larger and larger, and the angles at which the left and right baffles rotate around their respective baffle center lines first become larger and larger, and then become smaller and smaller. Through the above arrangement, the heat exchange tubes on the left and right sides of the shell where the center of the fluid is located strengthen the heat exchange, and then the heat exchange tubes at the upper and lower positions of the shell inlet and outlet at the front and rear ends strengthen the heat exchange. According to different positions, the heat exchange at different positions is strengthened, which changes the single heat exchange mode in the past, strengthens the heat exchange efficiency at different positions, makes the heat exchange uniform on the whole, and further achieves the purpose of strengthening heat transfer.

[0049] As an improvement, in the middle of the tube shell length direction, the rotation angle of the upper and lower baffles is the smallest, and the rotation angle of the left and right baffles is the largest. At the two ends of the tube shell length direction, the rotation angle of the upper and lower baffles is the largest, and the rotation angle of the left and right baffles is the smallest.

[0050] As an improvement, in the middle position of the tube shell in the length direction, the rotation angle of the upper and lower baffles is 0, that is, they do not rotate and remain vertically set. The rotation angle of the left and right baffles is 20-35°. At both ends of the tube shell in the length direction, the rotation angle of the upper and lower baffles is 20-35°, and the rotation angle of the left and right baffles is 0, that is, they do not rotate and remain vertically set.

[0051] Through the above arrangement, the heat exchange amount can be optimized and the heat exchange coefficient can be further improved.

[0052] 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 fan-shaped baffle group shell and tube cooler, the shell and tube heat exchanger comprises a tube shell, a heat exchange tube, a shell side inlet pipe and a shell side outlet pipe; the shell side inlet pipe and the shell side outlet pipe are respectively located at both ends of the heat exchanger; the heat exchange tube is arranged in the tube shell, and the heat exchange tube is fixedly connected to the tube sheet; characterized in that: A plurality of fan-shaped baffle groups are arranged in the tube shell, and the baffle group includes upper and lower baffles arranged in the vertical direction and left and right baffles arranged in the left and right direction, and the upper and lower baffles and the left and right baffles are spaced a certain distance apart; the upper and lower baffles include two fan-shaped baffles symmetrically arranged up and down along the center line of the tube shell, and the left and right baffles include fan-shaped baffles symmetrically arranged left and right along the center line of the tube shell; along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles in the baffle group to the area of ​​the left and right baffles gradually increases at first, and then gradually decreases after reaching a certain position.

2. The fan-shaped baffle group shell and tube cooler according to claim 1, characterized in that: The certain position is a middle position of the tube shell.

3. The fan-shaped baffle group shell and tube cooler according to claim 1, characterized in that: Along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles gradually increases.

4. The fan-shaped baffle group shell and tube cooler according to claim 1, characterized in that: Along the flow direction of the fluid in the shell side, the ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles gradually decreases.

5. The fan-shaped baffle group shell and tube cooler according to claim 1, characterized in that: The fan-shaped angle of the baffle group is 170-190°.

6. The fan-shaped baffle group shell and tube cooler according to claim 1, characterized in that: The fan-shaped angle of the baffle group is 180°.

7. The fan-shaped baffle group shell and tube cooler according to claim 1, characterized in that: The ratio of the area of ​​the upper and lower baffles to the area of ​​the left and right baffles is 0.9-1.2.

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