Cold wall type U-shaped tubular heat exchanger

Abstract

The utility model relates to the technical field of heat exchange, in particular to a cold wall type U-shaped tubular heat exchanger which comprises a tube bundle assembly, a tube pass assembly, a tube pass heat insulation assembly, a shell pass assembly and a shell pass drainage assembly, the shell pass assembly comprises a shell pass cylinder, and the shell pass cylinder is connected to a tube plate and used for being enclosed with the tube plate to form a closed shell pass cavity; the shell pass drainage assembly is positioned in the shell pass cavity and comprises a drainage barrel fixed on the shell pass barrel; a drainage interval is arranged between the end face of one side of the opening of the drainage barrel and the outer surface of the first side of the tube plate, wherein the low-temperature shell pass medium cooled through the U-shaped heat exchange tube flows out of the inner space to a shell pass cavity between the outer circumferential wall of the drainage barrel and the inner circumferential wall of the shell pass barrel through the drainage interval. According to the structure, the whole cold wall type effect of the shell side is achieved, the design temperature of the shell side pressure-bearing shell is greatly reduced, then the grade and the thickness of the shell material are reduced, and the cost is reduced; and the accident rate at the joint of the shell pass cylinder and the tube plate is reduced, and the maintenance cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of heat exchange, and more specifically, to a cold-wall U-tube heat exchanger. Background Art

[0002] Heat exchangers (also known as heat exchangers) play an important role in industrial sectors such as petroleum, chemical industry, light industry, food, and atomic energy. According to their structures, they can be divided into fixed tube sheet heat exchangers, U-tube heat exchangers, floating head heat exchangers, packed column heat exchangers, and kettle reboilers. Among them, the tube bundle of the U-tube heat exchanger can float freely without considering thermal stress due to temperature differences and can be used in large temperature difference scenarios. Moreover, it only uses one tube sheet, has fewer flanges, fewer leakage points, and a simple structure. At the same time, the tube bundle can be removed for cleaning, and it is the only heat exchanger suitable for high-temperature, high-pressure, and high-temperature difference scenarios.

[0003] Currently, most U-tube heat exchangers adopt the traditional inlet and outlet pipe arrangement methods (i.e., upper inlet and lower outlet or lower inlet and upper outlet). Due to the high-temperature and high-pressure characteristics of the application scenarios in chemical plants, the traditional structure corresponding to this pipe arrangement method will result in the need to use high-temperature-resistant and high-strength steel for the shell of the shell side during material selection, resulting in high costs. At the same time, there are large thermal stresses due to temperature differences between the upper and lower parts of the tube sheet in this traditional structure, and there are often problems such as easy leakage of the medium, difficult disassembly and maintenance, and high accident rates at the connection between the high-temperature area of the shell side and the tube sheet. Summary of the Utility Model

[0004] The purpose of this application is to provide a cold-wall U-tube heat exchanger, aiming to solve the technical problems in the prior art that due to the unreasonable structure setting of the U-tube heat exchanger, the cost of the shell of the shell side is high and the accident rate at the connection with the tube sheet is high.

[0005] To achieve this purpose, the technical solution adopted in this application is:

[0006] A cold-wall U-tube heat exchanger is provided, comprising: a tube bundle assembly including a tube sheet and U-shaped heat exchange tubes, the tube sheet having opposite first and second sides, the U-shaped heat exchange tubes being disposed on the first side of the tube sheet and passing through the tube sheet to have a heat exchange tube inlet and a heat exchange tube outlet located on the second side of the tube sheet; a tube side assembly including a tube side shell, the tube side shell being connected to the second side of the tube sheet and adapted to enclose with the tube sheet to form a sealed tube side cavity, a tube side inlet and a tube side outlet being formed on the tube side shell, the tube side inlet and the heat exchange tube inlet of the U-shaped heat exchange tubes being respectively communicated with the tube side cavity; a tube side heat insulation assembly located in the tube side cavity and including a heat insulation box body connected to the second side of the tube sheet, the interior of the heat insulation box body having a sealed heat insulation cavity, the heat exchange tube outlet of the U-shaped heat exchange tubes being communicated with the heat insulation cavity; a first interface being formed on the heat insulation box body, the tube side outlet being communicated with the heat insulation cavity through the first interface; a shell side assembly including a shell side shell, the shell side shell being connected to the first side of the tube sheet and adapted to enclose with the tube sheet to form a sealed shell side cavity; a shell side inlet and a shell side outlet being respectively formed on the side of the shell side shell away from the tube sheet, the shell side outlet being communicated with the shell side cavity; a shell side flow guiding assembly located in the shell side cavity and including a flow guiding shell fixed on the shell side shell, the flow guiding shell having an internal space with one side open, the U-shaped heat exchange tubes being received in the internal space through the open side; a second interface being formed on the side of the flow guiding shell away from its open side, the shell side inlet being communicated with the internal space through the second interface; a flow guiding gap is provided between the end face of the open side of the flow guiding shell and the outer surface of the first side of the tube sheet for the low-temperature shell side medium cooled by the U-shaped heat exchange tubes to flow out from the internal space to the shell side cavity between the outer peripheral wall of the flow guiding shell and the inner peripheral wall of the shell side shell.

[0007] In one or more embodiments, the tube sheet, the tube side shell, the heat insulation box body, the shell side shell and the flow guiding shell all have a circular cross-sectional shape, and the tube sheet, the tube side shell, the heat insulation box body, the shell side shell and the flow guiding shell are coaxially arranged.

[0008] In one or more embodiments, the flow guiding shell includes a large-end shell, a small-end shell, a conical shell connected between the large-end shell and the small-end shell, and a cover connected to the end of the small-end shell away from the conical shell, the large-end shell, the small-end shell, the conical shell and the cover being coaxially arranged, the open side being located on the side of the large-end shell away from the conical shell, and the second interface being provided on the small-end shell.

[0009] In one or more embodiments, a fixing assembly for fixing the drainage cylinder to the shell-side cylinder is provided between the outer circumferential wall of the large-end cylinder and the inner circumferential wall of the shell-side cylinder.

[0010] In one or more embodiments, the fixing assembly includes a supporting portion provided on the inner peripheral wall of the shell-side cylinder and an abutting portion provided on the outer peripheral wall of the large-end cylinder, and the abutting portion abuts against the top of the supporting portion.

[0011] In one or more embodiments, the number of the supporting parts and the number of the abutting parts are both two, the two supporting parts correspond one to one with the two abutting parts respectively, and the two abutting parts are located in the same horizontal plane and are respectively located on both sides of the outer peripheral wall of the large end cylinder.

[0012] In one or more embodiments, the supporting portion and the abutting portion are both arranged to extend along the axial direction of the drainage cylinder.

[0013] In one or more embodiments, the support portion and the abutment portion both have a rectangular cross-sectional shape.

[0014] In one or more embodiments, the shell-side drainage assembly further includes a distribution plate disposed in the internal space, wherein the distribution plate is fixedly connected to the inner circumferential wall of the large-end cylinder and is located between the outer end of the U-shaped heat exchange tube and the second interface.

[0015] In one or more embodiments, the insulation box body includes a small-end cylinder section provided with the first interface, a large-end cylinder section connected to the second side of the tube sheet, a cone section connected between the small-end cylinder section and the large-end cylinder section, and a cover plate connected to the end of the small-end cylinder section away from the cone section, and the small-end cylinder section, the large-end cylinder section, the cone section and the cover plate are coaxially arranged; the tube-side insulation component also includes an insertion component, the insertion component includes a fixed plate and an insertion tube arranged on the fixed plate, the fixed plate is connected to the circumferential inner wall of the large-end cylinder section and is used to divide the interior of the insulation box body into the insulation cavity and the cold wall cavity which are not connected to each other, and the cold wall cavity is enclosed by the fixed plate, the circumferential side wall of the large-end cylinder section and the tube sheet; the insertion tube is inserted into the U-shaped heat exchange tube from the heat exchange tube outlet and is used to transport the high-temperature tube-side medium flowing out of the heat exchange tube outlet to the insulation cavity.

[0016] In one or more embodiments, a flow hole connecting the tube side cavity with the cold wall cavity is provided on the side wall of the large end cylinder section.

[0017] In one or more embodiments, a heat insulation layer is provided between the insertion tube and the U-shaped heat exchange tube.

[0018] In one or more embodiments, the number of the U-shaped heat exchange tubes is multiple, the heat exchange tube outlets of the U-shaped heat exchange tubes are uniformly arranged in the central circular area on the second side surface of the tube sheet, and the heat exchange tube inlets of the U-shaped heat exchange tubes are uniformly arranged in the peripheral annular area outside the central circular area; the diameter of the inner tube wall of the large end cylinder section is larger than the diameter of the central circular area, and the diameter of the outer tube wall of the large end cylinder section is smaller than the small circle diameter of the peripheral annular area.

[0019] In one or more embodiments, a flexible connector is provided between the tube side outlet and the first interface and / or between the shell side inlet and the second interface.

[0020] The beneficial effects of the cold wall type U-tube heat exchanger provided by the present application are as follows: Compared with the prior art, a cold wall type U-tube heat exchanger proposed by the present application includes a tube bundle assembly, a tube side assembly, a tube side heat insulation assembly, a shell side assembly, and a shell side drainage assembly. Among them, by reasonably arranging the positions and connection relationships of the above components, especially by setting a drainage interval between the open end surface on one side of the drainage cylinder and the first side outer surface of the tube sheet, the hot medium at the shell side inlet can flow back into the shell side cavity between the outer peripheral wall of the drainage cylinder and the inner peripheral wall of the shell side cylinder before reaching the tube sheet after being cooled by the U-shaped heat exchange tubes. Since the shell side outlet is communicated with the shell side cavity, the low-temperature shell side medium finally cooled by the U-shaped heat exchange tubes can be discharged from the shell side outlet; this structure realizes the cold wall type effect of the whole shell side, enables the cold wall type U-tube heat exchanger to be applicable to high-temperature, high-pressure, and high-temperature difference occasions, and due to the setting of the cold wall type shell side, the design temperature of the shell side pressure-bearing shell can be greatly reduced, thereby reducing the grade and thickness of the shell material and saving the cost investment of the whole equipment; at the same time, by setting the drainage cylinder, the low-temperature shell side medium cooled by the U-shaped heat exchange tubes is guided to the space between the outer peripheral wall of the drainage cylinder and the inner peripheral wall of the shell side cylinder, so that the circumferential outer position where the tube sheet is connected to the shell side cylinder is in a lower temperature state, avoiding large thermal stress caused by the temperature difference between the upper and lower parts, solving the problems of easy leakage of the medium, difficult disassembly and maintenance, and high accident rate at the connection between the shell side cylinder and the tube sheet, reducing the maintenance cost, with uniform stress on the tube sheet, the heat exchanger can operate safely and stably, and is easy to be enlarged.

[0021] Other advantages of the present application and the technical effects of the preferred embodiments will be further described in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 is a schematic cross-sectional view of a cold-wall U-tube heat exchanger provided by an embodiment of the present application;

[0024] Figure 2 is a schematic cross-sectional view of a tube-side component provided by an embodiment of the present application;

[0025] Figure 3 is a schematic cross-sectional view of a shell-side component provided by an embodiment of the present application;

[0026] Figure 4 is a schematic cross-sectional view of a tube bundle component provided by an embodiment of the present application;

[0027] Figure 5 is a left view schematic diagram of a tube bundle component provided by an embodiment of the present application;

[0028] Figure 6 is a schematic cross-sectional view of a tube-side heat insulation component provided by an embodiment of the present application;

[0029] Figure 7 is a structural schematic diagram of a shell-side drainage component provided by an embodiment of the present application;

[0030] Figure 8 is a structural schematic diagram of a shell-side cylinder, a drainage cylinder, a heat insulation box, and a U-shaped heat exchange tube provided by an embodiment of the present application.

[0031] Among them, the reference numerals in the figure are as follows:

[0032] 1: tube-side component 11: tube-side cylinder 12: tube-side flange

[0033] 13: tube-side flat cover 14: tube-side inlet 15: tube-side outlet

[0034] 2: shell-side component 21: shell-side cylinder 22: shell-side flange

[0035] 23: shell-side flat cover 24: shell-side inlet 25: shell-side outlet

[0036] 26: support part

[0037] 3: tube bundle component 31: tube sheet 32: U-shaped heat exchange tube

[0038] 33: baffle plate 34: tie rod 35: spacer tube

[0039] 311: Peripheral annular region 312: Central circular region 321: Heat exchange tube inlet

[0040] 322: Heat exchange tube outlet

[0041] 4: Tube side heat insulation assembly 41: Cover plate 42: Small end flange

[0042] 43: Small end cylinder section 44: First interface 45: Taper section

[0043] 46: Large end flange 47: Insertion assembly 48: Inner cylinder flange

[0044] 49: Large end cylinder section 471: Fixed plate 472: Insertion tube

[0045] 491: Flow hole (upper) 492: Flow hole (lower)

[0046] 5: Shell side drainage assembly 51: Large end cylinder 52: Tapered shell

[0047] 53: Small end cylinder 54: Cover 55: Second interface

[0048] 56: Distribution plate 57: Contact portion H: Drainage interval

[0049] 6: Flexible connection member

[0050] 7: Fastener Detailed implementation manners

[0051] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as a limitation to the present application.

[0052] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0053] It should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0054] In this application, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] In addition, in the description of this application, the meaning of "a plurality of" is two or more, unless otherwise clearly and specifically defined.

[0056] A cold-wall U-tube heat exchanger provided in this application includes a tube bundle assembly 3, a tube side assembly 1, a tube side heat insulation assembly 4, a shell side assembly 2, and a shell side flow guiding assembly 5. Among them, the tube bundle assembly 3 includes a tube sheet 31 and U-shaped heat exchange tubes 32. The tube sheet 31 has opposite first and second sides. The U-shaped heat exchange tubes 32 are arranged on the first side of the tube sheet 31 and penetrate through the tube sheet 31 to have a heat exchange tube inlet 321 and a heat exchange tube outlet 322 located on the second side of the tube sheet 31. For details, reference can be made to Figure 1 and Figure 4 , An optional implementation is that the heat exchange tube inlet 321 and the heat exchange tube outlet 322 are located on the outer surface of the second side of the tube sheet 31, or the heat exchange tubes protrude from the outer surface of the second side of the tube sheet 31 after penetrating through the tube sheet 31. The specific protruding positions of the heat exchange tube inlet 321 and the heat exchange tube outlet 322 can be set according to actual situations. For example, after protruding, the heat exchange tube inlet 321 can be located in the subsequent tube side cavity, and the heat exchange tube outlet 322 after protruding can be located in the subsequent heat insulation cavity, cold wall cavity, or fixing plate 471. The specific positions are not limited here. In one or more embodiments, the tube bundle assembly 3 may further include baffle plates 33, tie rods 34, spacer tubes 35, etc. The baffle plates 33 can be multiple parallel partitions arranged around the U-shaped heat exchange tubes 32 to extend the flow path length of the shell side medium, increase the flow velocity between tubes, increase the degree of turbulence, and achieve the purpose of improving the heat transfer effect of the heat exchanger; the tie rods 34 can be used to support and fix the U-shaped heat exchange tubes 32 to prevent them from displacing or deforming; the spacer rods can be used to fix the baffle plates 33 and maintain the relative distance of the baffle plates 33 to ensure the heat exchange efficiency of the heat exchanger. The specific arrangement positions and connection conditions of the baffle plates 33, tie rods 34, and spacer tubes 35 can be referred to Figure 1 and Figure 4 .

[0057] The tube-side assembly 1 may include a tube-side barrel 11, which is connected to the second side of the tube sheet 31 and is used to enclose the tube sheet 31 to form a closed tube-side cavity. A tube-side inlet 14 and a tube-side outlet 15 are formed on the tube-side barrel 11. The tube-side inlet 14 and the heat exchange tube inlet 321 of the U-shaped heat exchange tube 32 are respectively connected to the tube-side cavity. In this way, the low-temperature tube-side medium can flow into the tube-side cavity through the tube-side inlet 14, and then enter the U-shaped heat exchange tube 32 through the heat exchange tube inlet 321 of the U-shaped heat exchange tube 32 for heat exchange. In one or more embodiments, the tube-side assembly 1 may also include a tube-side flange 12, a tube-side flat cover 13, a fastener 7 for connecting the tube-side flange 12 and the tube-side flat cover 13, etc. Figure 2 As shown, the pipe side flange 12 and the pipe side flat cover 13 can be enclosed together with the pipe side cylinder 11 and the tube sheet 31 to form the closed pipe side cavity. Of course, elastic sealing components can be added between the components as needed. The structure is simple and reliable, and can ensure that the pipe side cavity has good sealing performance.

[0058] The above-mentioned tube-side insulation component 4 is arranged in the tube-side cavity and may include an insulation box connected to the second side of the tube sheet 31. The insulation box has a closed insulation cavity inside. The heat exchange tube outlet 322 of the U-shaped heat exchange tube 32 is connected to the insulation cavity. The specific connection method can be achieved by arranging the heat exchange tube outlet 322 in the insulation cavity, or by connecting the two through other pipelines or components; a first interface 44 is formed on the insulation box, and the tube-side outlet 15 is connected to the insulation cavity through the first interface 44. In this way, the low-temperature tube-side medium is converted into a high-temperature tube-side medium after heat exchange through the U-shaped heat exchange tube 32. The high-temperature tube-side medium can flow into the insulation cavity through the heat exchange tube outlet 322 of the U-shaped heat exchange tube 32, and then be discharged through the first interface 44 and the tube-side outlet 15 in turn.

[0059] The shell side assembly 2 may include a shell side cylinder 21, which is connected to a first side of the tube sheet 31 and is used to enclose the tube sheet 31 to form a closed shell side cavity; the shell side cylinder 21 is formed with a shell side inlet 24 and a shell side outlet 25 on the side away from the tube sheet 31, and the shell side outlet 25 is connected to the shell side cavity, so that the high temperature shell side medium flows in through the shell side inlet 24, and after heat exchange with the U-shaped heat exchange tube 32, it can be converted into a low temperature shell side medium and flow into the shell side cavity, and can be discharged from the cavity through the shell side outlet 25; the shell side inlet 24 and the shell side outlet 25 are arranged on the side of the shell side cylinder 21 away from the tube sheet 31, which can be specifically referred to. Figure 1As can be seen from the figure, the tube sheet 31 is located on the left side of the shell-side cylinder 21, and the shell-side inlet 24 and the shell-side outlet 25 are both located on the right side of the shell-side cylinder 21. With this arrangement, on the one hand, the shell-side inlet 24 and the shell-side outlet 25 can be set on the same side to increase the flow path of the medium inside the shell-side cylinder 21, which is more conducive to heat exchange; on the other hand, the low-temperature shell-side medium after heat exchange can be returned to the same side for discharge to properly cool and protect the high-temperature components on the same side, thereby achieving a cold wall effect at the local high-temperature position and preventing the high-temperature components from leaking the medium, being difficult to disassemble and overhaul, and having a high accident rate. In one or more embodiments, the shell-side assembly 2 may also include a shell-side flange 22, a shell-side flat cover 23, a fastener 7 for connecting the shell-side flange 22 and the shell-side flat cover 23, etc., such as Figure 3 As shown, the shell side flange 22 and the shell side flat cover 23 can be enclosed together with the shell side cylinder 21 and the tube sheet 31 to form the closed shell side cavity. Of course, elastic sealing components can be added between the components as needed. The structure is simple and reliable, and can ensure that the shell side cavity has good sealing performance.

[0060] The shell-side drainage assembly 5 is located in the shell-side cavity and may include a drainage cylinder fixed on the shell-side cylinder 21. The drainage cylinder has an internal space with one side open, that is, one side of the internal space is provided with an opening, and the U-shaped heat exchange tube 32 can be accommodated in the internal space through the opening; the drainage cylinder is formed with a second interface 55 on the side away from the opening, and the shell-side inlet 24 is connected to the internal space through the second interface 55; a drainage interval H is provided between the end surface of the opening of the drainage cylinder and the first side outer surface of the tube sheet 31, such as Figure 1 As shown, the drainage interval H allows the low-temperature shell-side medium cooled by the U-shaped heat exchange tube 32 to flow out from the internal space to the shell-side cavity between the outer circumferential wall of the drainage cylinder and the inner circumferential wall of the shell-side cylinder 21. It can be understood that there only needs to be a gap between the outer circumferential wall of the drainage cylinder and the inner circumferential wall of the shell-side cylinder 21; further, the drainage cylinder can be coaxially arranged with the shell-side cylinder 21. At this time, the shell-side cavity between the outer circumferential wall of the drainage cylinder and the inner circumferential wall of the shell-side cylinder 21 has an annular cavity cross-section. In this way, the entire inner circumferential wall of the shell-side cylinder 21 is in contact with the low-temperature shell-side medium, and the cooling wall effect is better.

[0061] like Figure 1As shown, the high-temperature shell-side medium flows into the internal space through the shell-side inlet 24 and exchanges heat with the U-shaped heat exchange tubes 32 to be converted into a low-temperature shell-side medium. By setting the diversion interval H, the low-temperature shell-side medium can return and flow into the shell-side cavity between the outer peripheral wall of the diversion cylinder and the inner peripheral wall of the shell-side cylinder before reaching the tube sheet 31. Since the shell-side outlet 25 is connected to the shell-side cavity, the low-temperature shell-side medium cooled by the U-shaped heat exchange tubes 32 can finally be discharged from the shell-side outlet 25; this structure realizes the cold-wall effect between the outer peripheral wall of the diversion cylinder and the inner peripheral wall of the shell-side cylinder 21, enabling this cold-wall U-shaped tube heat exchanger to be applicable to high-temperature, high-pressure, and high-temperature difference occasions. Moreover, due to the setting of the cold-wall shell side, the design temperature of the shell-side pressure-bearing shell can be greatly reduced, thereby reducing the grade and thickness of the shell material and ultimately reducing the cost of the entire equipment; at the same time, by setting the diversion cylinder, the low-temperature shell-side medium cooled by the U-shaped heat exchange tubes 32 is guided to the space between the outer peripheral wall of the diversion cylinder and the inner peripheral wall of the shell-side cylinder 21, making the circumferential outer position where the tube sheet 31 is connected to the shell-side cylinder 21 in a lower temperature state, avoiding a large thermal stress difference between its upper and lower parts, solving the problems such as easy leakage of the medium, difficult disassembly and maintenance, and high accident rate at the connection between the shell-side cylinder 21 and the tube sheet 31, reducing the maintenance cost, with the tube sheet 31 being evenly stressed, the heat exchanger can operate safely and stably, and is easy to be scaled up.

[0062] As Figure 1 shown, the specific length dimension of the above-mentioned diversion interval H can be set according to the actual situation. In one or more embodiments of the present application, the medium flow area at the diversion interval H can be set to be larger than the notch area of the baffle 33 or the cross-sectional area of the shell-side inlet 24. In this way, the structure is simple and reasonable, fully ensuring the smoothness of the medium flow and improving the heat exchange efficiency of the shell-side medium.

[0063] In one or more embodiments of the present application, please refer to Figure 5 and Figure 8 , the tube sheet 31, the tube-side cylinder 11, the heat insulation box, the shell-side cylinder 21, and the diversion cylinder all have a circular cross-sectional shape, and the tube sheet 31, the tube-side cylinder 11, the heat insulation box, the shell-side cylinder 21, and the diversion cylinder are coaxially arranged. This structure is reasonable and stable, easy to process and assemble, and convenient for scaling up and mass production.

[0064] In one or more embodiments of the present application, please refer to Figure 1 and Figure 7The drainage cylinder includes a large end cylinder 51, a small end cylinder 53, a cone shell 52 connected between the large end cylinder 51 and the small end cylinder 53, and a cover 54 connected to the end of the small end cylinder 53 away from the cone shell 52. The large end cylinder 51, the small end cylinder 53, the cone shell 52 and the cover 54 are coaxially arranged, and the opening is located on the side of the large end cylinder 51 away from the cone shell 52. The second interface 55 is provided on the small end cylinder 53; by providing the large end cylinder 51, sufficient internal The internal space is used to accommodate the U-shaped heat exchange tube 32, which has a good heat exchange effect and a high shell cavity utilization rate; by arranging the small-end cylinder 53, the shell-side medium can have a higher flow velocity and turbulence when entering the internal space, which is conducive to heat exchange; by arranging the conical shell 52, the large-end cylinder 51 and the small-end cylinder 53 can be better transitioned and connected, and the large-end cylinder 51, the small-end cylinder 53, the conical shell 52 and the cover 54 are coaxially arranged, and the overall structure is easy to process and manufacture, and is convenient for large-scale production.

[0065] In one or more embodiments of the present application, a fixing assembly for fixing the drainage cylinder to the shell-side cylinder 21 is provided between the outer circumferential wall of the large-end cylinder 51 and the inner circumferential wall of the shell-side cylinder 21. The fixing assembly is used not only to support the shell-side drainage assembly 5, but also to support the U-shaped heat exchange tube 32 inside the drainage cylinder. Part of the weight of the entire U-shaped heat exchange tube 32 needs to be borne by the tube sheet 31, and the other part depends on the shell-side drainage assembly 5. It should be noted that the fixing assembly only needs to have sufficient strength to ensure that the drainage cylinder can be stably fixed on the shell-side cylinder 21, and the U-shaped heat exchange tube 32 can be stably arranged inside the drainage cylinder. The specific structure includes but is not limited to a screw structure, a clamping structure, a lap structure, a magnetic adsorption structure, etc.

[0066] As a specific implementation of the above-mentioned fixing component, please refer to Figure 7 and Figure 8 , the fixing assembly may include a support portion 26 provided on the inner peripheral wall of the shell-side cylinder 21 and an abutment portion 57 provided on the outer peripheral wall of the large-end cylinder 51, and the abutment portion 57 may abut against the upper portion of the support portion 26, that is, the support portion 26 may provide stable support for the abutment portion 57. In this embodiment, the large-end cylinder 51 may slide into the interior of the shell-side cylinder 21 and after obtaining the above-mentioned drainage interval H, the abutment portion 57 may always abut against the upper portion of the support portion 26. During the installation process, the support portion 26 not only supports the abutment portion 57, but also provides a guiding and limiting function for the coaxial arrangement of the drainage cylinder and the shell-side cylinder 21. In this way, the drainage cylinder can be reliably fixed in the shell-side cavity, ensuring the position stability of the drainage cylinder, thereby ensuring the position stability of the tube bundle assembly 3, and having good heat exchange stability. It should be noted that as long as the support portion 26 and the abutment portion 57 have sufficient support strength to ensure that the drainage cylinder can be stably fixed on the shell-side cylinder 21, the specific structure, size, number and abutment form are not limited.

[0067] In one or more embodiments of the present application, please refer to Figure 8 , the number of the supporting parts 26 and the abutting parts 57 is two. The two supporting parts 26 and the two abutting parts 57 correspond to each other one by one. The two abutting parts 57 can be located on the same horizontal plane and are respectively located on both sides of the outer peripheral wall of the large-end cylinder 51. This structure is simple and easy to process, and at the same time, it is convenient for the assembly and coaxial arrangement of the drainage cylinder and the shell-side cylinder 21. Figure 8 The positions of the shell-side cylinder 21, the large-end cylinder 51, the heat insulation box body, and the U-shaped heat exchange tubes 32 of the cold-wall type heat exchanger are shown. The large-end cylinder 51 of the drainage cylinder passes through the outer ends of the U-shaped heat exchange tubes 32 (i.e., Figure 4 the right tail ends of the U-shaped heat exchange tubes 32 in ), and is fixed on the supporting parts 26 in the shell-side cylinder 21 by means of the abutting parts 57 outside the large-end cylinder 51, so that the large-end cylinder 51 and the shell-side cylinder 21 are coaxially arranged; after the relative positional relationship between the drainage cylinder and the shell-side cylinder 21 is determined, axial limitation of the large-end cylinder 51 can be further carried out between the large-end cylinder 51 and the shell-side cylinder 21 through connection structures such as welding or bolt connection. Of course, other forms of axial limitation methods can also be used, and specific limitations are not made here.

[0068] In one or more embodiments of the present application, please refer to Figure 3 and Figure 7 , the supporting parts 26 and the abutting parts 57 can both be arranged to extend along the axial direction of the drainage cylinder. In this way, on the one hand, the structural strength of the supporting parts 26 and the abutting parts 57 can be improved, so that the drainage cylinder can be stably installed in the shell-side cylinder 21; on the other hand, the guiding and limiting capabilities of the supporting parts 26 can be improved, which is helpful for the assembly and coaxial arrangement of the drainage cylinder and the shell-side cylinder 21, and the structure is simple and easy to process.

[0069] In one or more embodiments of the present application, please refer to Figure 8 , the supporting parts 26 and the abutting parts 57 both have a rectangular cross-sectional shape. This structure is easy to process, and by setting the cross-sectional shapes of the supporting parts 26 and the abutting parts 57 to be rectangular, the upper surface of the supporting part 26 and the lower surface of the abutting part 57 can be in closer contact and fit, improving the guiding and supporting capabilities of the supporting part 26.

[0070] In one or more embodiments of the present application, please refer to Figure 1 and Figure 7The shell-side drainage assembly 5 also includes a distribution plate 56 disposed in the internal space, which is fixedly connected to the inner peripheral wall of the large-end cylinder 51 and is located between the outer end of the U-shaped heat exchange tube 32 and the second interface 55. The distribution plate 56 can be used to guide the flow direction of the medium at the shell-side inlet 24. Further, the distribution plate 56 can guide the medium at the shell-side inlet 24 to the outer peripheral wall of the drainage cylinder, and then cooperate with the baffle 33 to increase the turbulence degree and flow path of the medium, thereby improving the heat exchange efficiency.

[0071] In one or more embodiments of this application, please refer to Figure 1 and Figure 6 The heat-insulating box body may include a small-end barrel section 43 provided with a first interface 44, a large-end barrel section 49 connected to the second side of the tube sheet 31, a cone section 45 connected between the small-end barrel section 43 and the large-end barrel section 49, and a cover plate 41 connected to the end of the small-end barrel section 43 away from the cone section 45. The small-end barrel section 43, the large-end barrel section 49, the cone section 45 and the cover plate 41 may be coaxially arranged; the tube-side heat-insulating assembly 4 may also include an insertion assembly 47, which includes a fixing plate 471 and an insertion tube 472 provided on the fixing plate 471. The fixing plate 471 is connected to the circumferential inner wall of the large-end barrel section 49 and is used to separate the interior of the heat-insulating box body into a heat-insulating cavity and a cold wall cavity that are not connected to each other, such as Figure 1 As shown, the cold wall cavity can be enclosed by the fixed plate 471, the circumferential side wall of the large end cylinder section 49 (which can be understood as at least part) and the tube sheet 31; at the same time, the insert tube 472 can be inserted into the U-shaped heat exchange tube 32 through the heat exchange tube outlet 322 and is used to transport the high-temperature tube side medium flowing out of the heat exchange tube outlet 322 to the heat insulation cavity. Specifically, the insertion depth of the insert tube 472 is not specifically limited and can be set according to actual conditions. The setting of the insert tube 472 can play a role in heat insulation and protection of the high-temperature section of the U-shaped heat exchange tube. In one or more embodiments, as Figure 6As shown, the tube-side heat insulation box assembly further includes a small-end flange 42, a large-end flange 46, and an inner cylinder flange 48 to facilitate the connection between each cylinder section. By providing the large-end cylinder section 49, a sufficient cold-wall cavity can be obtained for cooling the high-temperature section of the U-shaped heat exchange tube. The cold-wall effect of the high-temperature section of the U-shaped heat exchange tube is good, and the utilization rate of the tube-side cavity is high. By providing the small-end cylinder section 43, the discharge rate of the tube-side medium can be increased, and the heat exchange efficiency can be improved. By providing the tapered section 45, the large-end cylinder section 49 and the small-end cylinder section 43 can be better transitioned and connected. The large-end cylinder section 49, the small-end cylinder section 43, the tapered section 45, and the cover plate 41 are coaxially arranged, and the overall structure is easy to machine and manufacture, facilitating large-scale production. At the same time, since the high-temperature medium in the tube side is drained to the tube-side outlet 15 through the tube-side heat insulation assembly 4 and then flows out, the low-temperature medium at the tube-side inlet 14 fills the entire tube-side cylinder 11. This structure realizes the cold-wall effect of the entire tube side, can greatly reduce the design temperature of the tube-side cylinder 11, and then reduce the grade and thickness of the tube-side cylinder 11, saving the cost investment of the entire equipment.

[0072] In one or more embodiments of the present application, please refer to Figure 1 and Figure 6 , and a communication hole is provided on the side wall of the large-end cylinder section 49 to connect the tube-side cavity and the cold-wall cavity. Optionally, as Figure 6 shown, a plurality of communication holes 491 can be opened in the upper part of the large-end cylinder section 49 of the tube-side heat insulation box assembly, and a plurality of communication holes 492 can also be opened in the lower part. The specific shape and size of the communication holes 491 and 492 are not limited herein. By providing the communication holes 491 and 492, the low-temperature tube-side medium in the tube-side cavity can flow into the cold-wall cavity to cool the part of the inserted tube 472 in the cold-wall cavity. By using the low-temperature medium in the peripheral tube side to cool the high-temperature inserted tube 472, the inserted tube 472 can achieve the cold-wall effect.

[0073] In one or more embodiments of the present application, an insulation layer can be provided between the inserted tube 472 and the U-shaped heat exchange tube 32, that is, the outer diameter of the inserted tube 472 can be slightly smaller than the diameter of the heat exchange tube outlet 322 of the U-shaped heat exchange tube 32, and a gap can be provided between the two. The above insulation layer can be provided at the gap to enable both the U-shaped heat exchange tube 32 and the tube sheet 31 at the high-temperature position to achieve the cold-wall effect.

[0074] In one or more embodiments of the present application, please refer to Figure 5 and Figure 8 , the number of U-shaped heat exchange tubes 32 is multiple, and the heat exchange tube outlets 322 of each U-shaped heat exchange tube 32 are uniformly arranged in the central circular area 312 (i.e., Figure 5 the central circular shaded part in Figure 5within the circular shaded part); the diameter of the inner cylindrical wall of the large-end cylinder section 49 is larger than the diameter of the central circular area 312, and the diameter of the outer cylindrical wall of the large-end cylinder section 49 is smaller than the diameter of the small circle of the outer peripheral annular area 311. In a specific embodiment, the large-end cylinder section 49 can be welded outside the central circular area 312 and inside the outer peripheral annular area 311. The cold medium at the tube-side inlet 14 can pass through the tube inlet 321 of the U-shaped heat exchange tube 32 in the outer peripheral annular area 311 on the tube sheet 31, and after being heated by heat exchange with the shell-side hot medium, it is discharged from the tube outlet 322 of the U-shaped heat exchange tube 32 in the central circular area 312 of the tube sheet 31. Specifically, multiple U-shaped heat exchange tubes 32 can be concentrically arranged. The tube inlet 321 of the U-shaped heat exchange tube 32 is arranged in the outer peripheral annular area 311 of the tube sheet 31 to construct a low-temperature medium inlet area outside the tube sheet 31, and the tube outlet 322 of the U-shaped heat exchange tube 32 is arranged in the central circular area 312 of the tube sheet 31 to construct a high-temperature medium outlet area in the middle of the tube sheet 31. This structure enables the joints of the tube sheet 31 with the tube-side cylinder 11 and the shell-side cylinder 21 to achieve the cold-wall effect.

[0075] From Figure 1 It can be seen that as a further optimization, a flexible connector 6 is provided between the tube-side outlet 15 and the first interface 44 and / or between the shell-side inlet 24 and the second interface 55. The flexible connector 6 can be used to adjust the expansion difference and manufacturing and installation errors of the tube-side outlet 15, the first interface 44, the shell-side inlet 24, or the second interface 55, thereby reducing the stress values of each component, facilitating the installation and connection between components, and improving the service life of each component.

[0076] As a summary, reference can be made to Figure 1 In the above-mentioned embodiment, the working principle of the cold-wall U-shaped tube heat exchanger applicable to high temperature, high pressure, and large temperature difference can be as follows:

[0077] Shell side: The hot medium (high-temperature shell-side medium) at the shell-side inlet 24, through the setting of the shell-side flow guiding assembly 5, first undergoes redistribution through the distribution plate 56, and then is cooled by the U-shaped heat exchange tube 32. It turns back through the shell-side cavity formed by the large-end cylinder 51 of the shell-side flow guiding assembly 5 and the shell-side cylinder 21 before reaching the tube sheet 31, and finally is discharged from the shell-side outlet 25, enabling the shell side to achieve the cold-wall effect. In this way, the design temperature of the shell-side cylinder 21 is greatly reduced, thereby reducing the grade and thickness of the shell material and saving the cost investment of the entire equipment.

[0078] Tube Pass: The cold medium (low-temperature tube pass medium) at the tube pass inlet 14 passes through the tube inlet 321 of the U-shaped heat exchange tube 32 in the peripheral annular area 311 of the tube sheet 31. After being heated by heat exchange with the hot medium in the shell pass, it is discharged from the tube outlet 322 of the U-shaped heat exchange tube 32 in the central circular area 312 of the tube sheet 31. Since the high-temperature medium in the tube pass is drained to the tube pass outlet 15 through the tube pass heat insulation component 4 and then flows out, the low-temperature medium at the tube pass inlet 14 fills the entire tube pass cylinder 11. This structure realizes the cold-wall effect of the entire tube pass, can greatly reduce the design temperature of the tube pass cylinder 11, and then reduce the grade and thickness of the tube pass cylinder 11, saving the cost investment of the entire equipment.

[0079] Tube Sheet: The tube inlet 321 of the U-shaped heat exchange tube 32 is arranged in the peripheral annular area 311 of the tube sheet 31 to construct a low-temperature medium inlet area around the tube sheet 31. By setting up a tube pass heat insulation box, the tube outlet 322 of the U-shaped heat exchange tube 32 is arranged in the central circular area 312 of the tube sheet 31 to construct a high-temperature medium outlet area in the middle of the tube sheet 31. This structure enables the joints between the tube sheet 31 and the tube pass cylinder 11 and the shell pass cylinder 21 to achieve the cold-wall effect. Moreover, the low-temperature medium at the tube pass inlet 14 fills the entire tube pass cylinder 11, making the circumferential outer peripheral position where the tube sheet 31 is connected to the tube pass cylinder 11 in a lower temperature state, avoiding the thermal stress caused by the temperature difference between the upper and lower parts of the tube sheet 31, and solving the problems of easy leakage of the medium at the joint between the tube pass cylinder 11 and the tube sheet 31 and difficult disassembly and maintenance.

[0080] Insertion Tube: By setting up the insertion tube 472 and the heat insulation layer between the insertion tube 472 and the U-shaped heat exchange tube 32, the connection between the high-temperature section of the U-shaped heat exchange tube 32 and the tube sheet 31 is in a lower temperature state, that is, achieving the cold-wall effect, which can effectively avoid problems such as leakage of the pipe joint at the connection between the U-shaped heat exchange tube 32 and the tube sheet 31. At the same time, by opening a plurality of circulation holes 491 in the upper part of the large end cylinder section 49 of the tube pass heat insulation box assembly and a plurality of circulation holes 492 in the lower part, the low-temperature tube pass medium in the tube pass cavity can flow into the cold-wall cavity to cool the part of the insertion tube 472 in the cold-wall cavity. By using the low-temperature medium in the peripheral tube pass to cool the high-temperature insertion tube 472, the insertion tube 472 achieves the cold-wall effect. In this way, the grade and thickness of the material of the insertion tube 472 can be reduced, saving the cost investment of the entire equipment.

[0081] The cold-wall U-tube heat exchanger in each of the above embodiments can achieve the cold-wall effect for the tube side, shell side, tube sheet, and inserted tubes. It has a simple structure and good stress distribution, and can reduce the cost of the heat exchanger by lowering the grade of materials used and the wall thickness. The positions where the tube sheet is connected to the shell-side cylinder, the positions where the tube sheet is connected to the tube-side cylinder, the high-temperature section of the U-shaped heat exchange tubes, and the outer walls of the inserted tubes are all in a relatively low-temperature state, avoiding large temperature difference thermal stresses at different positions of the tube sheet, reducing the loss rate of the tube sheet, ensuring the stability of the connection between the tube sheet and the shell-side and tube-side cylinders, solving problems such as easy leakage of the medium, difficult disassembly and maintenance, and high accident rates at the connections between the shell-side and tube-side cylinders and between the U-shaped heat exchange tubes and the tube sheet, and reducing the maintenance cost. Moreover, the tube sheet is uniformly stressed, the heat exchanger can operate safely and stably, and is easy to be scaled up. The structure operates stably and is easy to be scaled up, suitable for devices such as synthetic ammonia, waste heat boilers, and methanation, with a wide application range and good market prospects.

[0082] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, rather than limiting the embodiments of the present application. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A cold-wall U-tube heat exchanger, characterized in that, include: A tube bundle assembly, comprising a tube sheet and a U-shaped heat exchange tube, wherein the tube sheet has a first side and a second side opposite to each other, the U-shaped heat exchange tube is arranged on the first side of the tube sheet and penetrates the tube sheet to have a heat exchange tube inlet and a heat exchange tube outlet located on the second side of the tube sheet; A tube-side assembly, comprising a tube-side cylinder, the tube-side cylinder being connected to the second side of the tube sheet and used to enclose the tube sheet to form a closed tube-side cavity, a tube-side inlet and a tube-side outlet being formed on the tube-side cylinder, the tube-side inlet and the heat exchange tube inlet of the U-shaped heat exchange tube being respectively connected to the tube-side cavity; A tube-side heat insulation assembly is located in the tube-side cavity and includes a heat insulation box connected to the second side of the tube sheet, wherein the heat insulation box has a closed heat insulation cavity inside, and the heat exchange tube outlet of the U-shaped heat exchange tube is connected to the heat insulation cavity; a first interface is formed on the heat insulation box, and the tube-side outlet is connected to the heat insulation cavity through the first interface; A shell-side assembly, comprising a shell-side barrel, the shell-side barrel being connected to a first side of the tube sheet and used to enclose the tube sheet to form a closed shell-side cavity; the shell-side barrel is respectively formed with a shell-side inlet and a shell-side outlet on a side away from the tube sheet, and the shell-side outlet is communicated with the shell-side cavity; A shell-side drainage assembly is located in the shell-side cavity and includes a drainage cylinder fixed on the shell-side cylinder, the drainage cylinder has an internal space with one side open, and the U-shaped heat exchange tube is accommodated in the internal space via the opening; the drainage cylinder is formed with a second interface on the side away from its opening, and the shell-side inlet is connected with the internal space via the second interface; a drainage gap is provided between the end surface of one side of the opening of the drainage cylinder and the first side outer surface of the tube sheet for the low-temperature shell-side medium cooled by the U-shaped heat exchange tube to flow out from the internal space to the shell-side cavity between the outer peripheral wall of the drainage cylinder and the inner peripheral wall of the shell-side cylinder.

2. The cold-wall U-tube heat exchanger according to claim 1, wherein, The tube sheet, the tube-side cylinder, the thermal insulation box, the shell-side cylinder and the drainage cylinder all have a circular cross-sectional shape, and the tube sheet, the tube-side cylinder, the thermal insulation box, the shell-side cylinder and the drainage cylinder are coaxially arranged.

3. The cold-wall U-tube heat exchanger according to claim 2, characterized in that, The drainage cylinder includes a large end cylinder, a small end cylinder, a conical shell connected between the large end cylinder and the small end cylinder, and a cover connected to the end of the small end cylinder facing away from the conical shell. The large end cylinder, the small end cylinder, the conical shell and the cover are coaxially arranged, the opening is located on the side of the large end cylinder facing away from the conical shell, and the second interface is provided on the small end cylinder.

4. The cold-wall U-tube heat exchanger according to claim 3, wherein, A fixing assembly for fixing the drainage cylinder on the shell-side cylinder is provided between the outer circumferential wall of the large-end cylinder and the inner circumferential wall of the shell-side cylinder.

5. The cold-wall U-tube heat exchanger according to claim 4, characterized in that, The fixing assembly comprises a supporting portion arranged on the inner peripheral wall of the shell-side cylinder and an abutting portion arranged on the outer peripheral wall of the large-end cylinder, wherein the abutting portion abuts against the upper portion of the supporting portion.

6. The cold-wall U-tube heat exchanger according to claim 5, wherein, The number of the supporting parts and the number of the abutting parts are both two, the two supporting parts correspond to the two abutting parts respectively, the two abutting parts are located in the same horizontal plane and are respectively located on both sides of the outer peripheral wall of the large end cylinder; and / or, The supporting portion and the abutting portion are both arranged to extend along the axial direction of the drainage cylinder; and / or, The support portion and the abutment portion each have a rectangular cross-sectional shape.

7. The cold-wall U-tube heat exchanger according to claim 3, wherein The shell-side drainage assembly also includes a distribution plate arranged in the internal space. The distribution plate is fixedly connected to the inner peripheral wall of the large-end cylinder and is located between the outer end of the U-shaped heat exchange tube and the second interface.

8. The cold-wall U-tube heat exchanger according to any one of claims 2-7, characterized in that The thermal insulation box body includes a small-end cylinder section provided with the first interface, a large-end cylinder section connected to the second side of the tube sheet, a cone section connected between the small-end cylinder section and the large-end cylinder section, and a cover plate connected to the end of the small-end cylinder section away from the cone section, the small-end cylinder section, the large-end cylinder section, the cone section and the cover plate are coaxially arranged; the tube-side insulation component also includes an insertion component, the insertion component includes a fixed plate and an insertion tube arranged on the fixed plate, the fixed plate is connected to the circumferential inner wall of the large-end cylinder section and is used to divide the interior of the thermal insulation box body into the thermal insulation cavity and the cold wall cavity which are not connected to each other, the cold wall cavity is enclosed by the fixed plate, the circumferential side wall of the large-end cylinder section and the tube sheet; the insertion tube is inserted into the U-shaped heat exchange tube from the heat exchange tube outlet and is used to transport the high-temperature tube-side medium flowing out of the heat exchange tube outlet to the thermal insulation cavity.

9. The cold-wall U-tube heat exchanger according to claim 8, wherein, A flow hole is provided on the side wall of the large end cylinder section for connecting the tube side cavity with the cold wall cavity; and / or, A heat insulation layer is provided between the insertion tube and the U-shaped heat exchange tube; and / or, There are multiple U-shaped heat exchange tubes, and the heat exchange tube outlet of each U-shaped heat exchange tube is arranged in the central circular area of the second side surface of the tube plate, and the heat exchange tube inlet of each U-shaped heat exchange tube is arranged in the outer annular area of the central circular area; the diameter size of the inner cylinder wall of the large end cylinder section is larger than the diameter size of the central circular area, and the diameter size of the outer cylinder wall of the large end cylinder section is smaller than the small circle diameter size of the outer annular area.

10. The cold-wall U-tube heat exchanger according to any one of claims 1-7 and 9, characterized in that, A flexible connector is provided between the tube side outlet and the first interface and / or between the shell side inlet and the second interface.

Images