A sector baffle group shell-and-tube heat exchanger

Abstract

The application provides a sector baffle group tube-shell cooler, the baffle group comprises up-down baffles arranged in the up-down direction and left-right baffles arranged in the left-right direction, the up-down baffles and the left-right baffles are spaced apart by a certain distance; the up-down baffles comprise two sector baffles symmetrically arranged along the center line of the tube shell in the up-down direction, and the left-right baffles comprise sector baffles symmetrically arranged along the center line of the tube shell in the left-right direction; along the flow direction of the fluid in the shell side, the area ratio of the up-down baffles to the left-right baffles in the baffle group is gradually increased first, and then gradually decreased after reaching a certain position. According to the different positions, the application strengthens the heat exchange of different positions, and further achieves the purpose of strengthening the heat transfer.

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, the demand for heat exchangers in industrial production has increased in order to reduce energy consumption, and the quality requirements for heat exchangers have also become increasingly higher. In recent decades, although compact heat exchangers (plate, plate-fin, and press-welded plate heat exchangers, etc.), heat pipe heat exchangers, and direct contact heat exchangers 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 equipment still accounts for about 70% of all heat exchangers.

[0003] Shell-and-tube heat exchangers remain the mainstream type of heat exchange equipment due to their simple structure and ability to withstand high pressures. While the commonly used bow-shaped baffles are simple to manufacture, they suffer from flow dead zones, high flow resistance, and a large tube bundle support span at the notch, which can easily induce vibration damage. This has led to the emergence of many new tube bundle support solutions, including spiral baffles. Theoretically, spiral baffles are curved surfaces, making them difficult to manufacture. Currently, there are improved solutions for 1 / 4 elliptical / sector-shaped spiral baffles, where each layer of baffles consists of four 1 / 4 elliptical / sector-shaped baffles, connected end-to-end to form a shell-side spiral channel. Since shell-and-tube heat exchangers largely use the most compact tube bundles arranged in equilateral triangles, this creates significant difficulties in marking and positioning the inclined tube holes on the 1 / 4 elliptical / sector-shaped baffles, hindering the widespread application of this type of baffle.

[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. Baffles with this structure often cause the flow medium to form a short-circuit diversion phenomenon at the inner wall of the shell and the boundary of the baffle. The short-circuit diversion 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, baffles with 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] But 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 and the like. Therefore, under the new energy saving and emission reduction situation, its development is greatly limited. Therefore, in view of these shortcomings, a baffle and shell-and-tube heat exchanger with simple structure and mature technology is developed, so that the heat exchange area and heat exchange efficiency can be effectively improved, which has very important significance for industrial production and energy saving and emission reduction. SUMMARY

[0006] In order to overcome the defects and deficiencies in the prior art, the present application provides a new layout of baffle plate for shell-and-tube heat exchanger, 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-mentioned purpose, the technical scheme of the present application is as follows:

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

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

[0010] As an improvement, along the flow direction of the fluid in the shell side, the area ratio of the upper and lower baffle plates to the left and right baffle plates is gradually increased with an increasing amplitude.

[0011] As an improvement, along the flow direction of the fluid in the shell side, the area ratio of the upper and lower baffle plates to the left and right baffle plates is gradually decreased with a decreasing amplitude.

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

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

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

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

[0016] 1) The present application 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. This makes the fluid in the shell side gradually more and more close to the left and right direction, that is, the middle position of the upper and lower direction, so that the heat exchange of the heat exchange tube is strengthened at the middle position of the tube shell length direction. At the two ends of the tube shell, the heat exchange of the heat exchange tube is strengthened at the upper and lower positions. According to the different positions, the heat exchange at different positions is strengthened, the single heat exchange mode in the past is changed, the heat exchange efficiency at different positions is strengthened, the overall heat exchange is uniform, and the purpose of strengthening heat transfer is further achieved.

[0017] 2) By changing the distance between the baffles, the heat exchange area of the tube side fluid and the shell side fluid in the baffle is changed, so that the uneven heat exchange is compensated by the area change, thereby further improving the heat exchange efficiency. BRIEF DESCRIPTION OF DRAWINGS

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

[0019] Figure 2 is a top view schematic diagram of the baffle group of the present application;

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

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

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

[0023] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0024] In this paper, if not specially stated, the " / " represents division, and the "×", "*" represents multiplication.

[0025] A tube and shell heat exchanger (cooler), such as Figure 1As shown, the shell and tube heat exchanger is arranged horizontally, including a tube shell 1, heat exchange tubes 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 tubes 8 are arranged in the tube shell 1, and the heat exchange tubes are 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, with injection water in the tube side and cold water in the shell side, 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 to the area of ​​the left and right baffles in the baffle group first gradually increases, 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 position 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 the 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, preferably 0.8 times, the shell diameter.

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

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

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

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

[0036] As an improvement, the sum of the included angles of the fan-shaped baffles 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] Through the optimization design of the above parameters, the heat exchange efficiency can be optimized.

[0039] As an improvement, the shell side and the tube side are countercurrent flow, and along the flow direction of the fluid in the tube side, the distance between the baffles gradually increases from the tube inlet to the middle position of the tube. Then, the distance between the baffles gradually decreases from the middle position of the tube to the tube outlet. Because in the countercurrent process, the heat exchange per unit length of the shell side and the tube side along the flow process of the fluid is relatively uniform, the overall heat exchange effect is the best. However, it is found in experiments and simulations that the heat exchange in the middle is significantly greater than that at the inlet and outlet of the tube side. Therefore, by changing the distance between the baffles, the heat exchange area between the fluid in the tube side and the fluid in the shell side is also changed. Therefore, through the area change, the non-uniformity of the heat exchange is compensated, and the heat exchange efficiency is further improved.

[0040] As an improvement, along the flow direction of the fluid in the tube side, the increasing amplitude of the distance between the baffles gradually increases from the tube inlet to the middle position of the tube. Then, the decreasing amplitude of the distance between the baffles gradually decreases from the middle position of the tube to the tube outlet. The change of the above amplitude can make the heat exchange per unit length of the entire fluid movement more uniform, and further improve the heat exchange efficiency.

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

[0042] As an improvement, the control system comprises a temperature sensor 13, a flow controller 14 and a central controller 12, the flow controller controls the flow rate of the heat source into the heat exchanger; the temperature sensor is used to measure the outlet temperature of the cold source of the tube side, when the temperature of the cold source is lower than a first temperature, the flow controller is fully opened, when the outlet temperature of the cold source reaches the first temperature, the central controller controls the flow controller to reach a first flow rate, which is lower than the flow rate when the flow controller is fully opened, when the outlet temperature of the cold source reaches a second temperature higher than the first temperature, the central controller controls the flow controller to reach a second flow rate lower than the first flow rate, when the outlet temperature of the cold source 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 outlet temperature of the cold source 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 outlet temperature of the cold source 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 the temperature exceeding the upper limit of the predetermined data, and the first temperature is the temperature lower than the lower limit of the predetermined data. Through the above settings, the heat exchange capacity of the heat exchanger can be controlled according to the temperature, achieving the effect of saving heat source.

[0044] As an improvement, the control system can be a single-chip microcomputer, and a control panel can be provided, which can be arranged on the upper part or lower part of the heat exchanger, or on the pipeline entering the heat exchanger.

[0045] As an improvement, the top points (centers) of the upper baffle and the left baffle and the right baffle are located on the center line of the tube shell, i.e. the line composed of the center points of the cross section.

[0046] Normally, the baffles are arranged in the vertical direction. As an improvement, the upper baffle and the left baffle and the right baffle are rotated around their respective baffle center lines by a certain angle, i.e. the baffles are inclined at a certain angle to the vertical plane. The baffle center line is the line connecting the top point (center) of the sector and the midpoint of the arc of the sector. By rotating by a certain angle, the fluid can form a spiral baffle effect, improving the heat exchange coefficient.

[0047] As an improvement, the rotation angles of the upper baffle and the lower baffle arranged symmetrically are opposite, and the rotation angles of the left baffle and the right baffle arranged symmetrically are opposite. For example, from the top, the upper baffle rotates clockwise, and the lower baffle rotates counterclockwise. Or 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 rotation angle of the upper and lower baffles around the respective baffle centerlines is first increasingly smaller and then increasingly larger, and the rotation angle of the left and right baffles around the respective baffle centerlines is first increasingly larger and then increasingly smaller. Through the above arrangement, the heat exchange of the heat exchange tubes on the left and right sides of the fluid center in the shell is strengthened, and then the heat exchange of the heat exchange tubes at the upper and lower positions of the inlet and outlet of the shell at the two ends is strengthened. According to the different positions, the heat exchange of different positions is strengthened, the past single heat exchange mode is changed, the heat exchange efficiency of different positions is strengthened, the overall heat exchange is uniform, and the purpose of strengthening heat transfer is further achieved.

[0049] As an improvement, at the middle position in the length direction of the shell, 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 in the length direction of the shell, 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, at the middle position in the length direction of the shell, the rotation angle of the upper and lower baffles is 0, that is, no rotation, and remains vertically arranged. The rotation angle of the left and right baffles is 20-35°. At the two ends in the length direction of the shell, 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, no rotation, and remains vertically arranged.

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

[0052] Although the present application has been disclosed with reference to the preferred embodiments, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A shell-and-tube heat exchanger with a sector baffle assembly, comprising a shell and tube, heat exchange tubes, 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 tubes are arranged in the shell and tube, and the heat exchange tubes are 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 directions, 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 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; the certain position is the middle position of the tube shell.

2. The sector baffle group shell and tube heat exchanger 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.

3. The shell and tube heat exchanger with fan-shaped baffles 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 to a smaller and smaller extent.

4. The shell and tube heat exchanger with fan-shaped baffles according to claim 1, characterized in that: The fan-shaped angle of the baffle group is 170-190°.

5. The shell and tube heat exchanger with sector baffles according to claim 1, characterized in that: The fan-shaped angle of the baffle group is 180°.

6. The shell and tube heat exchanger with sector baffles according to claim 1, characterized in that: The area ratio of the upper and lower baffles to the left and right baffles is 0.9-1.2.

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