Anti-freezing structure of shell-and-tube heat exchanger

Abstract

The utility model relates to the field of heat exchanger anti-freezing structure design, in particular to an anti-freezing structure of a shell-and-tube heat exchanger. Comprising a tube box, a shell, a pass partition plate, a tube bundle, an upper baffle plate and a lower baffle plate, a tube pass inlet and a tube pass outlet are respectively formed in the side part of the tube box; a shell pass inlet and a shell pass outlet are formed in two ends of the shell; blow-down pipe groups are arranged between the plurality of lower baffle plates and the inner wall of the shell; the bottom of the shell is communicated with a blow-off pipe group; the blow-down pipe group is laid on the lower baffle plate and the bottom of the inner wall of the shell; when the equipment needs to be emptied, condensed water or heat exchange fluid stored in the shell between the lower baffle plates can be isolated and communicated through the blow-down pipe group and can be discharged through the blow-down pipe group in time, and the blow-down pipe group is communicated with the blow-down pipe group through the blow-down pipe group, so that the blow-down efficiency of the equipment is improved. The tube bundle expansion displacement damage to the tube bundle and the tube plate connecting port caused by the freezing of the tube bundle at the bottom due to the too high accumulated water level is avoided.

Description

Technical Field

[0001] The utility model relates to the field of heat exchanger antifreeze structure design, in particular to a tube and shell type heat exchanger antifreeze structure. Background Art

[0002] Shell and tube heat exchangers are composed of shell, heat transfer tube bundle, tube sheet, baffle (baffle) and tube box. The shell is mostly cylindrical, with tube bundle inside, and both ends of the tube bundle are fixed on the tube sheet. Shell and tube heat exchangers are usually used in industries such as industry, pharmaceuticals, and chemicals to exchange hot and cold fluids. In winter, due to the low ambient temperature, condensed water will freeze in the shell and tube heat exchanger, causing serious damage to the equipment.

[0003] The most commonly used anti-freezing measure is to set a drain pipe or a vent pipe at the bottom of the shell to drain the condensate or heat exchange fluid remaining in the shell before it is not in operation for a long time; although there are gaps between the baffles and the tube bundles, and between the baffles and the inside of the shell, after long-term use, such gaps will be blocked by scale, resulting in the adjacent lower baffles being unable to communicate with each other, and the accumulated condensate or fluid cannot be emptied in time through the drain pipe, and the accumulated water level is higher than the bottom tube bundle. After freezing, the bottom tube bundle expands and displaces, damaging the connection between the tube bundle and the tube sheet, causing the heat exchange fluid medium to penetrate and leak. Utility Model Content

[0004] In order to solve the technical problem that the condensed water or heat exchange fluid in the shell cannot be drained and causes the bottom tube bundle to freeze, the utility model provides an antifreeze structure for a shell and tube heat exchanger.

[0005] The technical problem of the utility model is achieved through the following technical solutions: a shell and tube heat exchanger antifreeze structure, including a tube box and a shell; the tube box and the shell are fixedly connected; a partition plate is arranged in the tube box; an upper baffle and a lower baffle are arranged in sequence in the shell; a tube bundle penetrating the upper baffle and the lower baffle is arranged in the shell; the port of the tube bundle is connected to the tube box; a tube side inlet and a tube side outlet are respectively opened on the tube box, and a shell side inlet and a shell side outlet are respectively arranged at the upper and lower parts of the two ends of the shell; a vent pipe group is arranged between a plurality of the lower baffles and the inner wall of the shell; and a sewage pipe group is connected to the bottom of the shell.

[0006] By using the above technical scheme, a vent pipe group is laid at the bottom of the inner wall of the lower baffle and the shell; thereby the cavity separated by the lower baffle in the shell is connected, and further connected to the drain pipe group. When the equipment needs to be vented, the condensed water or heat exchange fluid stored in the shell between the lower baffles can be connected through the vent pipe group and discharged through the drain pipe group in time, so as to avoid the freezing of the tube bundle at the bottom due to the excessively high accumulated water level and the resulting freezing, which will cause the expansion and displacement of the tube bundle and damage the connection between the tube bundle and the tube sheet, and the mutual penetration of the heat exchange fluid medium, or damage to the tube bundle itself.

[0007] Preferably, the vent pipe group includes a vent pipe and a through slot; the vent pipe is closely connected to the bottom of the shell; the upper part of the vent pipe is embedded in the lower baffle, and a plurality of through slots are arranged at intervals on the vent pipe.

[0008] By using the above technical solution, the accumulated water between the shell outlet and the lower baffle is discharged from the shell outlet, and the heat exchange fluid in the shell can be prevented from excessively flowing along the through-grooves of the vent pipe group, affecting the flow path of the heat exchange fluid between the upper baffle and the lower baffle, thereby reducing the heat exchange efficiency.

[0009] Preferably, the sewage pipe group includes a sewage pipe and a sewage valve. The sewage pipe is installed through the outer bottom of the shell; the sewage valve is installed on the sewage pipe.

[0010] Preferably, a lower baffle is provided between the end of the vent tube group away from the shell side inlet and the shell side outlet.

[0011] Preferably, the tube side inlet is connected to the inner cavity of the tube box at the upper part of the partition plate; and the tube side outlet is connected to the inner cavity of the tube box at the lower part of the partition plate.

[0012] Preferably, the communication port of the tube side outlet connected to the tube box is lower than the bottommost discharge port of the tube bundle.

[0013] By using the above technical solution, it can be ensured that the heat exchange fluid in the tube bundle is completely emptied, preventing the fluid from freezing in the tube bundle and causing damage to the tube bundle.

[0014] Preferably, a buffer plate is further provided inside the shell between the shell-side inlet and the tube bundle.

[0015] By using the above technical solution, the setting of the buffer plate can reduce the excessive impact of the heat exchange fluid at the shell side inlet on the tube bundle below it, causing damage to the tube bundle.

[0016] In summary, the utility model has the following beneficial effects:

[0017] 1. The antifreeze structure of the shell and tube heat exchanger of the utility model is achieved by laying a vent pipe group at the bottom of the inner wall of the lower baffle and the shell; thereby the cavity separated by the lower baffle in the shell is connected, and further connected with the sewage pipe group. When the equipment needs to be vented, the condensed water or heat exchange fluid stored in the shell between the lower baffles can be connected through the vent pipe group and discharged through the sewage pipe group in time, so as to avoid the freezing of the tube bundle at the bottom due to excessively high accumulated water level and freezing, causing the tube bundle to expand and displace, damaging the connection between the tube bundle and the tube sheet, and the heat exchange fluid medium to penetrate each other, or damaging the tube bundle itself.

[0018] 2. The end of the vent tube group close to the shell outlet and the lower baffle between the shell outlet, so that the accumulated water between the shell outlet and the lower baffle here is discharged from the shell outlet, and the heat exchange fluid in the shell is prevented from excessively flowing along the through-notch of the vent tube group, affecting the flow path of the heat exchange fluid between the upper baffle and the lower baffle, thereby reducing the heat exchange efficiency.

[0019] 3. The connecting port of the tube side outlet connected to the tube box is lower than the bottom outlet of the tube bundle, which can ensure that the heat exchange fluid in the tube bundle is completely discharged to prevent the fluid from freezing in the tube bundle and causing damage to the tube bundle; the setting of the buffer plate can reduce the excessive impact of the heat exchange fluid at the shell side inlet on the tube bundle below it, causing damage to the tube bundle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a cross-sectional view of the antifreeze structure of the shell and tube heat exchanger of the utility model;

[0021] Figure 2 This is a front view of the antifreeze structure of the shell and tube heat exchanger of the utility model;

[0022] Figure 3 for Figure 1 The cross-sectional view at AA of the

[0023] Figure 4 This is a schematic diagram of the vent pipe group structure;

[0024] Figure 5 This is a schematic diagram of the connection method between the tube side inlet and the tube side outlet of Example 2.

[0025] Description of reference numerals:

[0026] 1. Pipe box; 2. Shell; 3. Partition baffle; 4. Upper baffle; 5. Lower baffle; 6. Tube bundle; 7. Tube inlet; 8. Tube outlet; 9. Shell inlet; 10. Shell outlet; 11. Vent pipe group; 111. Vent pipe; 112. Through slot; 12. Drain pipe group; 121. Drain pipe; 122. Drain valve; 13. Buffer plate. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or component needs to have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0029] As mentioned above, the utility model proposes a shell and tube heat exchanger antifreeze structure, now combined with the attached Figure 1-5 Further explanation.

[0030] Embodiment 1:

[0031] This embodiment provides a shell and tube heat exchanger antifreeze structure plate, such as Figure 1 As shown, it comprises a tube box 1 and a shell 2; the tube box 1 and the shell 2 are fixedly connected by flanges; a partition plate 3 is arranged in the tube box 1; the partition plate 3 divides the tube box 1 into two cavities that are not interconnected from top to bottom, a tube sheet is sandwiched between the tube box 1 and the shell 2, the tube sheet serves as a mounting plate for a tube bundle 6, the feed port and the discharge port of the tube bundle 6 are respectively connected through the tube sheet, so as to communicate with the two cavities of the tube box 1 divided by the partition plate 3, the tube sheet is welded to the port of the shell 2, and the tube bundle 6 adopts a U-shaped tube bundle; upper and lower cavities are arranged in sequence in the shell 2 Baffle 4 and lower baffle 5; the tube bundle 6 arranged in the shell 2 penetrates and connects the upper baffle 4 and the lower baffle 5; the upper baffle 4 fits the upper wall of the inner cavity of the shell 2; the lower baffle 5 fits the lower wall of the inner cavity of the shell 2; the port of the tube bundle 6 is connected to the pipe box 1; the pipe box 1 is respectively provided with a tube side inlet 7 and a tube side outlet 8, the tube side inlet 7 is located at the upper end of the pipe box 1; the tube side outlet 8 is located at the lower end of the pipe box 1; the tube side inlet 7 is connected to the inner cavity of the pipe box 1 at the upper part of the partition plate 3; the tube side outlet 8 is connected to the inner cavity of the pipe box 1 at the lower part of the partition plate 3. A heat exchange fluid enters the cavity of the tube box 1 above the partition plate 3 from the tube side inlet 7, flows out through the tube bundle 6, enters the cavity of the tube box 1 below the partition plate 3, and finally flows out from the tube side outlet 8; heat exchange is completed, or vice versa, enters from the tube side outlet 8 and flows out from the tube side inlet 7; the upper and lower parts of the two ends of the shell 2 are respectively provided with a shell side inlet 9 and a shell side outlet 10; another heat exchange fluid enters the shell 2 from the shell side inlet 9 at the upper end of one side of the shell 2, passes through the forced drainage of the upper baffle 4 and the lower baffle 5, and finally flows out from the shell side outlet 10 at the lower end of the other side of the shell 2; or vice versa, enters from the shell side outlet and flows out from the shell side inlet 9; heat exchange is completed.

[0032] like Figure 1 , Figure 3 and Figure 4 As shown, a vent pipe group 11 is arranged between several lower baffles 5 and the inner wall of the shell 2; the vent pipe group 11 is laid at the bottom of the inner cavity of the shell 2 to connect the adjacent chambers of the shell 2 separated by the lower baffle 5; a sewage pipe group 12 is also connected to the bottom of the shell 2, and the sewage pipe group 12 is located in the middle position of the bottom of the shell 2; the vent pipe group 11 includes a vent pipe 111 and a through slot 112; the vent pipe 111 preferably adopts an arc plate with a semicircular structure, and the arc plate is attached to the bottom of the inner cavity of the shell 2; a plurality of notches for fluid inflow, namely the through slots 112, are provided on the pipe body of the vent pipe 111; except for the lower baffle 5 closest to the shell outlet 10, the vent pipe 111 is clamped at the bottom of the lower baffle 5; welding can be used for fixed connection when necessary.

[0033] like Figure 1 As shown, the lower baffle 5 arranged between the end of the vent tube group 11 far away from the shell side inlet 9 and the shell side outlet 10 is not provided with the vent tube group 11 as much as possible; to prevent the lower baffle 5 from being connected with the cavity at the end of the shell 2 and other cavities, so that the heat exchange fluid for heat exchange flows directly from one end of the shell 2 through the vent tube group 11 to the shell side outlet 10, affecting the heat exchange efficiency.

[0034] Further, such as Figure 2 As shown, the sewage pipe group 12 includes a sewage pipe 121 and a sewage valve 122. The sewage pipe 121 is installed through the outer bottom of the shell 2; it is preferably arranged in the middle position, and the sewage valve 122 is installed on the sewage pipe 121. The sewage valve 122 controls the opening and closing of the sewage pipe 121, such as a stop valve, a ball valve, etc.

[0035] At the same time, a buffer plate 13 is also arranged inside the shell 2 between the shell inlet 9 and the tube bundle 6; the buffer plate 13 reduces the falling fluid flow rate at the shell inlet 9, avoiding long-term impact on the tube bundle 6 causing the welding point between the tube bundle 6 and the tube sheet to rupture, causing the two heat exchange fluids to leak from each other.

[0036] Example 2: Figure 5 As shown, the difference from Example 1 is that in this embodiment, the tube side inlet 7 and the tube side outlet 8 connected to the tube box 1 are arranged at the side end of the tube box 1; the communication port of the tube side outlet 8 is lower than the bottom end outlet of the tube bundle 6. When the tube side outlet 8 is located at the side end of the tube box 1 instead of the bottom end, it is ensured that the heat exchange fluid remaining in the tube box 1 flows out as much as possible to avoid backflow into the tube bundle 6, causing freezing and damage to the tube bundle;

[0037] The working principle of the utility model is: the heat exchange fluid in the shell 2 and the tube bundle 6 is emptied to avoid the residual fluid from freezing the device, based on the original sewage pipe group 12; a vent pipe group 11 is arranged between the lower baffle 5 and the inner wall of the shell 2; the vent pipe 111 of the vent pipe group 11 together with the two separated cavities blocked by the structure, the residual heat exchange fluid in the shell 2 is discharged through the vent pipe 111 and the through slot 112; finally, it converges into the cavity connected to the sewage pipe group 12 and flows out, and the residual heat exchange fluid located at the shell outlet 10 flows out from the shell outlet 10, thereby achieving the antifreeze effect.

[0038] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A shell and tube heat exchanger antifreeze structure, comprising a tube box (1) and a shell (2); the tube box (1) and the shell (2) are fixedly connected; a partition plate (3) is arranged in the tube box (1); an upper baffle (4) and a lower baffle (5) are arranged in sequence in the shell (2); a tube bundle (6) penetrating the upper baffle (4) and the lower baffle (5) is arranged in the shell (2); a port of the tube bundle (6) is connected to the tube box (1); and the characteristics are as follows: The tube box (1) is provided with a tube-side inlet (7) and a tube-side outlet (8), and the upper and lower ends of the shell (2) are provided with a shell-side inlet (9) and a shell-side outlet (10), respectively. A vent pipe group (11) is provided between the lower baffles (5) and the inner wall of the shell (2). The bottom of the shell (2) is connected to a sewage pipe group (12).

2. The antifreeze structure of a shell and tube heat exchanger according to claim 1, characterized in that: The vent pipe group (11) comprises a vent pipe (111) and a through slot (112); the vent pipe (111) is closely connected to the bottom of the shell (2); the upper part of the vent pipe (111) is engaged with the lower baffle (5), and a plurality of through slots (112) are arranged at intervals on the vent pipe (111).

3. The antifreeze structure of a shell and tube heat exchanger according to claim 2, characterized in that: The sewage pipe group (12) comprises a sewage pipe (121) and a sewage valve (122); the sewage pipe (121) is installed through the outer bottom of the shell (2); and the sewage valve (122) is installed on the sewage pipe (121).

4. The antifreeze structure of a shell and tube heat exchanger according to claim 2, characterized in that: A lower baffle (5) is provided between the end of the vent pipe group (11) away from the shell side inlet (9) and the shell side outlet (10).

5. The antifreeze structure of a shell and tube heat exchanger according to claim 1, characterized in that: The tube-side inlet (7) is connected to the inner cavity of the tube box (1) above the partition plate (3); and the tube-side outlet (8) is connected to the inner cavity of the tube box (1) below the partition plate (3).

6. The antifreeze structure of a shell and tube heat exchanger according to claim 2, characterized in that: The communication port of the tube pass outlet (8) connected to the tube box (1) is lower than the bottommost outlet of the tube bundle (6).

7. The antifreeze structure of a shell and tube heat exchanger according to claim 1, characterized in that: A buffer plate (13) is also provided inside the shell (2) between the shell-side inlet (9) and the tube bundle (6).

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