Heat exchange tube nest and fuming sulfuric acid cooler

Abstract

The embodiment of the utility model provides a heat exchange tube nest and a fuming sulfuric acid cooler, and belongs to the technical field of heat exchange equipment. The heat exchange tube nest is used in the heat exchanger, the heat exchanger comprises a shell pass used for circulating liquid to be subjected to heat exchange, and a tube pass used for circulating a heat exchange medium is formed in the heat exchange tube nest. The heat exchange tube nest comprises a tube body and a plurality of heat exchange tubes, wherein a plurality of concave areas are arranged along the peripheral wall of the tube body; the multiple baffle plates are arranged on the peripheral wall of the pipe body and arranged at intervals in the axial direction of the pipe body, and each baffle plate can change the flow direction of liquid to be subjected to heat exchange. According to the heat exchange tube nest, the concave areas and the baffle plates are additionally arranged on the peripheral wall of the tube body, so that the heat exchange efficiency of the heat exchange tube nest is enhanced, and the outlet temperature of fuming sulfuric acid can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat exchange equipment, and in particular relates to a heat exchange tube and a fuming sulfuric acid cooler. Background Art

[0002] The acid cooler of sulfuric acid plant generally adopts shell-and-tube heat exchanger, and the heat exchange tube is the key component of the shell-and-tube heat exchanger, which determines the efficiency of the heat exchanger. The heat exchange tube of the traditional acid cooler is ordinary stainless steel tube, which has low heat exchange efficiency. The temperature of oleum discharged from the heat exchanger outlet is too high. The temperature of oleum entering the absorption tower is too high, which will lead to problems such as decreased absorption effect, increased acid mist, and corrosion of equipment. Utility Model Content

[0003] In view of the above problems in the prior art, the purpose of the embodiment of the utility model is to provide a heat exchange tube and a fuming sulfuric acid cooler. The heat exchange tube increases the heat exchange efficiency of the heat exchange tube by adding a recessed area and a baffle on the outer peripheral wall of the tube body, thereby reducing the outlet temperature of the fuming sulfuric acid.

[0004] The technical solution adopted in the embodiment of the utility model is:

[0005] A heat exchange tube is used in a heat exchanger, wherein the heat exchanger comprises a shell side for circulating a liquid to be exchanged, and the interior of the heat exchange tube forms a tube side for circulating a heat exchange medium; the heat exchange tube comprises:

[0006] The tube body has a plurality of recessed areas along the outer peripheral wall;

[0007] A plurality of baffles are respectively arranged on the outer peripheral wall of the tube body and are spaced apart along the axial direction of the tube body. Each of the baffles can change the flow direction of the liquid to be heat exchanged.

[0008] Furthermore, the tube body is a straight tube.

[0009] Furthermore, the shape of the recessed area is elliptical.

[0010] Further, the depth of the recessed area is 0.2cm-0.4cm;

[0011] The length of the major axis of the depressed area is 3 cm to 5 cm;

[0012] The length of the short axis of the depressed area is 1 cm-2 cm.

[0013] Furthermore, the height of the baffle along the radial direction of the tube body is 1 cm-5 cm.

[0014] Furthermore, the plurality of recessed areas are divided into M groups along the axial direction of the tube body, and the recessed areas of each group are arranged at intervals around the axis of the tube body;

[0015] The plurality of baffles are divided into N groups along the axial direction of the tube body, and the baffles of each group are arranged at intervals around the axis of the tube body, wherein M and N are both positive integers.

[0016] Furthermore, M groups of recessed areas and N groups of baffles are alternately arranged in the axial direction of the tube body.

[0017] Furthermore, the baffle is placed on the outer peripheral wall of the tube in a spiral shape.

[0018] Furthermore, along the axial direction of the tube body, the rotation directions of two adjacent groups of baffles are opposite. A fuming sulfuric acid cooler comprises a heat exchange tube array as described in any one of the above embodiments.

[0019] Compared with the prior art, the beneficial effects of the embodiments of the present invention are:

[0020] The heat exchange tubes of this embodiment are provided with a plurality of recessed areas and a plurality of baffles on the tube body. The recessed areas on the peripheral wall not only enable the liquid to be heat exchanged to generate vortices, so as to improve the convection heat transfer coefficient on the outer surface of the heat exchange tubes. At the same time, due to the recessed areas on the peripheral wall, a plurality of convex hulls appear on the inner wall of the tube body, so that the flow cross section of the heat exchange medium changes periodically, and then the flow velocity of the heat exchange medium also changes periodically. This oscillating flow strengthens the convective heat transfer of the tube body and significantly improves the heat exchange efficiency. In addition, a plurality of baffles can continuously change the flow direction of the liquid to be heat exchanged, further increase the degree of turbulence, and further improve the heat exchange efficiency of the heat exchange tubes. The heat exchange tubes improve the heat exchange efficiency and can reduce the outlet temperature of oleum acid.

[0021] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to restrict the present invention.

[0022] The overview of various implementations or examples of the technology described in this utility model is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the embodiments of the utility model. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts.

[0024] Figure 1This is a front view of the heat exchange tubes of the embodiment of the utility model;

[0025] Figure 2 This is a cross-sectional view of the heat exchange tubes of the embodiment of the utility model.

[0026] In the figure: 1, tube body; 2, recessed area; 3, baffle. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings of the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] In order to keep the following description of the embodiments of the present invention clear and concise, the present invention omits detailed descriptions of known functions and known components.

[0030] The embodiment of the utility model provides a heat exchange tube, which is a plurality of heat exchange tubes, which are respectively arranged in a heat exchanger. The heat exchanger includes a shell side for circulating the liquid to be exchanged, and the interior of the heat exchange tube forms a tube side, and the heat exchange medium circulates in the heat exchange tube.

[0031] It should be noted that the area between the outer peripheral wall of the heat exchange tubes in the heat exchanger and the inner wall of the shell of the entire heat exchanger is the shell side, so that the liquid to be exchanged flowing in the shell side can contact the outer peripheral wall of the heat exchange tubes, and then exchange heat with the heat exchange medium flowing in the heat exchange tubes.

[0032] like Figure 1 and Figure 2 As shown, the heat exchange tube array of this embodiment includes a tube body 1 and a plurality of recessed areas 2 and a plurality of baffles 3 arranged on the outer peripheral wall of the tube body 1 .

[0033] The recessed area 2 on the outer wall of the tube body 1 can cause the liquid to be heat exchanged to generate a vortex in the recessed area 2, and the heat exchange liquid flowing out of the recessed area 2 can be violently mixed with the mainstream, thereby improving the convective heat transfer coefficient of the outer surface of the heat exchange tube.

[0034] At the same time, the concave area 2 on the outer peripheral wall of the tube body 1 can form a convex hull correspondingly on the inner peripheral wall of the tube body 1, thereby reducing the flow cross section of the heat exchange medium at the convex hull in the tube body 1, thereby increasing the flow speed of the heat exchange medium at the convex hull in the tube body 1. On the contrary, in the area where the convex hull is not provided on the inner peripheral wall of the tube body 1, the flow speed of the heat exchange medium will be reduced.

[0035] The periodic convex hulls on the inner circumference of the heat exchange tubes will cause the flow cross section of the heat exchange medium to change periodically, thereby causing the flow velocity of the heat exchange medium to change periodically. This oscillating flow strengthens the convective heat exchange of the tube body 1 and significantly improves the heat exchange efficiency.

[0036] Furthermore, a plurality of baffles 3 are arranged at intervals along the axial direction of the tube body 1, so as to continuously change the flow direction of the liquid to be heat exchanged, further increase the degree of turbulence, and further improve the heat exchange efficiency of the heat exchange tubes.

[0037] The tube body 1 of the heat exchange tube in this embodiment is provided with a plurality of recessed areas 2 and a plurality of baffles 3, which enhances the heat exchange efficiency of the heat exchange tube.

[0038] like Figure 1 As shown, in some embodiments, the concave areas 2 on the tube body 1 are all elliptical, and the long axis direction of each concave area 2 is consistent with the axial direction of the tube body 1. The tube body 1 is a straight tube.

[0039] Usually, in a heat exchanger, the extension direction of the heat exchange tubes is consistent with the flow direction of the liquid to be heat exchanged in the shell side. For some heat exchangers, when the liquid to be heat exchanged flowing in the shell side is oleum, boundary layer separation will occur when the oleum flows through the front edge of the depression area 2, and the upper shear layer will form an unsteady vortex and fall off periodically; when the oleum hits the rear edge of the depression area 2, it will flow upward and mix violently with the mainstream; when the oleum flows through the bottom of the depression area 2, a secondary flow can be generated at the bottom of the depression area 2 to generate a vortex. The above changes in flow state all increase the surface flow heat transfer coefficient between the exothermic nicotinic acid and the outer surface of the heat exchange tubes.

[0040] It should be explained that the front edge of the recessed area 2 of this embodiment can be understood as the end where the liquid to be heat exchanged flows into the recessed area 2, and the rear edge of the recessed area 2 can be understood as the end where the liquid to be heat exchanged flows out of the recessed area 2.

[0041] Preferably, the outer diameter of the tube body 1 of the heat exchange tube in this embodiment is Φ2 cm, the tube wall thickness is 0.15 cm, and the length is 1000 cm.

[0042] Furthermore, the depth of the recessed area 2 on the tube body 1 is 0.2 cm-0.4 cm, preferably 0.3 cm.

[0043] The length of the long axis of the recessed area 2 is 3 cm-5 cm, preferably 4 cm. The length of the short axis of the recessed area 2 is 1 cm-2 cm, preferably 1.5 cm. The height of the baffle 3 along the radial direction of the tube body 1 is 1 cm-5 cm, preferably 3 cm.

[0044] like Figure 1 As shown, in some embodiments, the plurality of recessed areas 2 on the tube body 1 are divided into a plurality of groups along the axial direction of the tube body 1 .

[0045] In each group of recessed areas 2, four recessed areas 2 may be arranged along a circumference of the tube body 1. Two adjacent groups of recessed areas 2 are alternately arranged along the axial direction of the tube body 1.

[0046] Likewise, if Figure 1 As shown, the multiple baffles 3 are also divided into multiple groups along the axial direction of the tube body 1. In each group of baffles 3, four baffles 3 can be arranged around the tube body 1. Two adjacent groups of baffles 3 can also be alternately arranged along the axial direction of the tube body 1.

[0047] Furthermore, in this embodiment, multiple groups of recessed areas 2 and multiple groups of baffles 3 are alternately arranged on the outer peripheral wall of the tube body 1. That is, a group of baffles 3 is arranged between two adjacent groups of recessed areas 2, and when the heat exchange liquid flows out of the previous group of recessed areas 2, it will change its flow direction after passing through the baffles 3 between them, and then just flow into the next group of recessed areas 2.

[0048] In some embodiments, the baffles 3 are spirally disposed on the outer peripheral wall of the tube body 1. When the liquid to be heat exchanged impacts the surface of the baffles 3, the liquid to be heat exchanged will change its flow direction.

[0049] In some embodiments, along the axial direction of the tube body 1, the rotation directions of two adjacent groups of baffles 3 are opposite.

[0050] For example, one of the two adjacent groups of baffles 3 has a left-handed rotation direction, and the other group of baffles 3 has a right-handed rotation direction. When the heat exchange liquid impacts the first group of baffles 3 and changes direction, it can impact the second group of baffles 3. In this way, the heat exchange liquid can flow in a zigzag form along the axial direction of the tube body 1 under the action of multiple groups of baffles 3, thereby increasing the contact time with the outer peripheral surface of the tube body 1.

[0051] The present embodiment also provides a oleum acid cooler, which adopts a shell-and-tube heat exchanger, which includes a heat exchange tube as described in any one of the above embodiments, and there are multiple heat exchange tubes, which are arranged at intervals in the oleum acid cooler. Both ends of the heat exchange tubes can be fixed in the oleum acid cooler by a fixing plate or other methods. The structure belongs to the prior art and will not be described in detail.

[0052] Furthermore, in the oleum acid cooler of this embodiment, the heat exchange medium flowing in the heat exchange tubes is cooling water, and the liquid to be heat exchanged flowing in the shell side is oleum, and the oleum acid cooler reduces the outlet temperature of oleum.

[0053] The following is an example in which the number of heat exchange tubes in the oleum cooler is 15, the inlet flow rate of oleum entering the shell side of the cooler is 326t / h, the temperature is 80℃, and the flow rate of cooling water entering the tube side of the cooler is 417t / h, the temperature is 32℃.

[0054] Example 1

[0055] The depth of the concave area 2 on the heat exchange tube in the oleum acid cooler is 0.3 cm, the major axis length of the concave area 2 is 4 cm, the minor axis length of the concave area 2 is 1.5 cm, the height of the baffle 3 is 3 cm, and in the axial direction of the heat exchange tube, the rotation direction of one of the two adjacent groups of baffles 3 is left-handed, and the rotation direction of the other group of baffles 3 is right-handed, and the helical angle of the baffle 3 is 45 degrees. After cooling in the oleum acid cooler, the outlet temperature of the oleum is 45°C.

[0056] Example 2

[0057] Compared with Example 1, the depth of the depressed area 2 on the heat exchange tubes in the oleum acid cooler is 0.2 cm. After cooling in the oleum acid cooler, the outlet temperature of the oleum is 51°C.

[0058] Example 3

[0059] Compared with Example 1, the depth of the depressed area 2 on the heat exchange tubes in the oleum acid cooler is 0.4 cm. After being cooled in the oleum acid cooler, the outlet temperature of the oleum is 50°C.

[0060] Example 4

[0061] Compared with Example 1, the major axis length of the depressed area 2 on the heat exchange tubes in the oleum acid cooler is 3 cm. After being cooled in the oleum acid cooler, the outlet temperature of the oleum is 52°C.

[0062] Example 5

[0063] Compared with Example 1, the major axis length of the depressed area 2 on the heat exchange tubes in the oleum acid cooler is 5 cm. After being cooled in the oleum acid cooler, the outlet temperature of the oleum is 51°C.

[0064] Example 6

[0065] Compared with Example 1, the minor axis length of the depressed area 2 on the heat exchange tubes in the oleum acid cooler is 1 cm. After cooling in the oleum acid cooler, the outlet temperature of the oleum is 53°C.

[0066] Example 7

[0067] Compared with Example 1, the minor axis length of the depressed area 2 on the heat exchange tubes in the oleum acid cooler is 2 cm. After being cooled in the oleum acid cooler, the outlet temperature of the oleum is 52°C.

[0068] Example 8

[0069] Compared with Example 1, the height of the baffles 3 on the heat exchange tubes in the oleum acid cooler is 1 cm. After cooling in the oleum acid cooler, the outlet temperature of the oleum is 54°C.

[0070] Example 9

[0071] Compared with Example 1, the height of the baffles 3 on the heat exchange tubes in the oleum acid cooler is 5 cm. After cooling in the oleum acid cooler, the outlet temperature of the oleum is 52°C.

[0072] Specifically, the experimental data of the above embodiments 1 to 9 are shown in the following table:

[0073]

[0074] Preferably, the depth of the recessed area 2 on the heat exchange tube in the oleum acid cooler of this embodiment is preferably 0.3 cm, the major axis length of the recessed area 2 is preferably 4 cm, and the minor axis length of the recessed area 2 is preferably 1.5 cm. The height of the baffle 3 is preferably 3 cm.

[0075] In the axial direction of the heat exchange tubes, one of the two adjacent groups of baffles 3 has a left-handed rotation direction, and the other group of baffles 3 has a right-handed rotation direction. When the inlet temperature of the cooling water is 32°C, the flow rate is 417t / h, the inlet temperature of the oleum is 80°C, and the inlet flow rate is 326t / h, the outlet temperature of the oleum is less than or equal to 45°C.

[0076] The above description is intended to be illustrative rather than restrictive, and those skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure. Moreover, the above examples (or one or more of them) may be used in combination with each other, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations.

Claims

1. A heat exchange tube, used in a heat exchanger, wherein the heat exchanger comprises a shell side for circulating a liquid to be exchanged, and the interior of the heat exchange tube forms a tube side for circulating a heat exchange medium; characterized in that: The heat exchange tubes include: The tube body has a plurality of recessed areas on its outer peripheral wall; A plurality of baffles are respectively arranged on the outer peripheral wall of the tube body and are spaced apart along the axial direction of the tube body. Each of the baffles can change the flow direction of the liquid to be heat exchanged.

2. A heat exchange tube according to claim 1, characterized in that: The tube body is a straight tube.

3. A heat exchange tube according to claim 1, characterized in that: The shape of the recessed area is elliptical.

4. A heat exchange tube as claimed in claim 3, characterized in that: The depth of the depressed area is 0.2 cm to 0.4 cm; The length of the major axis of the depressed area is 3 cm to 5 cm; The length of the short axis of the depressed area is 1 cm-2 cm.

5. A heat exchange tube as claimed in claim 4, characterized in that: The height of the baffle along the radial direction of the tube body is 1 cm-5 cm.

6. The heat exchange tube according to claim 1, characterized in that: The plurality of recessed areas are divided into M groups along the axial direction of the tube body, and the recessed areas in each group are arranged at intervals around the axis of the tube body; The multiple baffles are divided into N groups along the axial direction of the tube body, and the baffles in each group are arranged at intervals around the axis of the tube body; wherein M and N are both positive integers.

7. A heat exchange tube as claimed in claim 6, characterized in that: The M groups of recessed areas and the N groups of baffles are alternately arranged in the axial direction of the tube body.

8. A heat exchange tube according to claim 7, characterized in that: The baffle is spirally arranged on the outer peripheral wall of the tube body.

9. A heat exchange tube as claimed in claim 8, characterized in that: Along the axial direction of the tube body, the rotation directions of two adjacent groups of baffles are opposite.

10. A fuming sulfuric acid cooler, characterized in that: A heat exchange tube comprising any one of claims 1 to 9.

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