A high-efficiency interphase spiral pipe compact heat exchanger easy to maintain

Abstract

The present application relates to reactor main heat exchanger technical field, especially to a kind of high-efficiency phase interval spiral pipe compact heat exchanger of easy maintenance.The high-efficiency phase interval spiral pipe compact heat exchanger of easy maintenance of the present application includes tube shell, heat exchange tube group, import header and export header, the heat exchange tube group includes heat exchange tube, the rising section and the falling section of the heat exchange tube are folded after whole and are spirally wound in the tube shell, and the two ends of the heat exchange tube are worn out the tube shell, and respectively with the import header and export header can be detachably connected.The advantage: heat exchange tube bundle assembly is easy to disassemble, easy to maintain, and at the same time, the rising section and the falling section of heat exchange tube are arranged in the phase interval mode of parallel flow common spiral winding, and the heat exchange efficiency is higher.

Description

Technical Field

[0001] This invention relates to the field of reactor main heat exchanger technology, and in particular to an easy-to-maintain, high-efficiency interphase spiral tube compact heat exchanger. Background Technology

[0002] The reactor main heat exchanger is a crucial device that transfers heat from the primary coolant to the secondary coolant, generating the high-parameter medium required for secondary power generation. Currently, reactor steam generators commonly use various structural forms, which can be broadly categorized into: straight-tube, coaxial, U-tube, and spiral tube types.

[0003] Straight-tube heat exchangers are mostly used in the main heat exchangers of loop-type sodium-cooled reactors, and are less commonly used in other reactors. A straight-tube heat exchanger consists of vertically arranged heat exchange tubes, with both ends welded to a tube sheet. These heat exchangers have a simple structure and are easy to manufacture and assemble. However, because the tube side and shell side are constrained together, they have weak resistance to thermal deformation and require specialized structures to overcome thermal stress.

[0004] Shell-and-tube heat exchangers are rarely used in reactors, but have been used in limited quantities in early sodium-cooled reactor steam generators and marine pressurized water reactor steam generators. A shell-and-tube heat exchanger is an improvement on a straight-tube heat exchanger, consisting of concentric nested tubes added along the length of a straight tube. Fluid flows in an annular region between the inner heat exchange tubes and the beam-and-tube heat exchanger, resulting in better heat transfer performance than straight-tube heat exchangers. However, the shell-and-tube structure is relatively complex to manufacture.

[0005] U-tube main heat exchangers are most widely used in large, loop-type pressurized water reactor nuclear power plants, such as the US AP series reactors and China's Hualong One reactor, whose steam generators all adopt this structure. U-tube main heat exchangers are characterized by their simple structure, mature manufacturing process, and strong axial thermal deformation resistance of the tube bundles. However, the tube bundle arrangement of the U-shaped heat exchanger tubes is not compact, and the fluids in both the tube side and shell side flow almost axially along the heat exchanger tubes, resulting in low fluid disturbance and relatively low heat transfer performance.

[0006] Helical tube heat exchangers, due to their high heat exchange efficiency and compact structure, are widely used in integrated pool reactors or high-temperature gas-cooled reactors. Helical tube heat exchangers feature a compact tube bundle coil arrangement, large free expansion space for the wound tubes, and enhanced heat transfer through secondary helical flow. However, the fluid inlet and outlet of traditional helical tube heat exchangers are located at the top and bottom of the heat exchanger, respectively, making them unsuitable for pool reactor structures. In pool reactors, helical tube heat exchangers typically have a central downcomer arranged in layers in the center of the helical coil bundle, and this central downcomer area is usually designated as a heat exchange dead zone. Therefore, the larger the thermal power and size of the pool-type helical tube heat exchanger, the larger the central heat exchange dead zone, resulting in greater wastage of space in critical areas of the reactor pressure vessel.

[0007] Currently, in the design of integrated small modular reactors, the size of the reactor pressure vessel is becoming increasingly smaller, placing increasingly stringent requirements on the structural dimensions of the reactor's main heat exchanger. Therefore, there is an urgent need to design a heat exchanger structure with strong heat transfer performance and a high effective heat transfer area ratio. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an easy-to-maintain, high-efficiency interphase spiral tube compact heat exchanger, which effectively overcomes the defects of the prior art.

[0009] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0010] A high-efficiency, easily maintainable, interphase spiral tube compact heat exchanger includes a shell, a heat exchange tube assembly, an inlet header, and an outlet header. The heat exchange tube assembly includes heat exchange tubes, the rising and falling sections of which are folded in half and spirally wound around the shell. The two ends of the heat exchange tubes extend out of the shell and are detachably connected to the inlet header and the outlet header, respectively.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the aforementioned heat exchange tube assembly includes at least two of the aforementioned heat exchange tubes.

[0013] Furthermore, the aforementioned inlet header and outlet header are located at the same end of the aforementioned shell and tube, and the two ends of the aforementioned heat exchange tubes respectively extend from one end of the aforementioned shell and tube.

[0014] Furthermore, the aforementioned inlet header includes multiple arc-shaped inlet pipe sections, and the joints corresponding to the descending sections of the aforementioned heat exchange tubes are connected and communicated with any one or more of the aforementioned inlet pipe sections.

[0015] Furthermore, the aforementioned outlet manifold includes multiple arc-shaped outlet pipe sections, and the joints corresponding to the rising sections of the aforementioned heat exchange tubes are connected and communicated with any one or more of the aforementioned outlet pipe sections.

[0016] Furthermore, the aforementioned heat exchange tube assembly is provided in multiple groups, and is distributed at intervals from the inside out.

[0017] Furthermore, a support partition is provided between two adjacent sets of the above-mentioned heat exchange tube groups, and the end of the support partition is connected to an installation plate sleeved on the outside of the above-mentioned central column.

[0018] Furthermore, it also includes an elastic support assembly, which is installed on the periphery of the multiple sets of heat exchange tubes and elastically supported on the inner wall of the tube shell.

[0019] Furthermore, the aforementioned elastic support assembly includes a tube bundle casing and an elastic compensation ring. The tube bundle casing is fitted around the periphery of the multiple sets of the aforementioned heat exchange tube assemblies, and the compensation ring is assembled on the outside of the tube bundle casing and contacts the inner wall of the tube shell.

[0020] Furthermore, the longitudinal section of the aforementioned compensation ring is an outwardly convex arc shape, the upper end of the aforementioned compensation ring is connected and fixed to the outer surface of the aforementioned tube bundle casing, and the outwardly convex portion of the aforementioned compensation ring contacts the inner wall of the aforementioned tube casing.

[0021] The beneficial effects of this invention are: the rising and falling sections of the heat exchange tube are arranged in a parallel spiral winding phase, resulting in higher heat exchange efficiency. Attached Figure Description

[0022] Figure 1 This is a structural cross-sectional view of the easily maintainable, high-efficiency interphase spiral tube compact heat exchanger of the present invention.

[0023] Figure 2 This is a top view of the end face structure of the easily maintainable, high-efficiency interphase spiral tube compact heat exchanger of the present invention.

[0024] Figure 3 This is a diagram showing the arrangement of heat exchange tubes in the easily maintainable, high-efficiency interphase spiral tube compact heat exchanger of the present invention.

[0025] The attached diagram lists the components represented by each number as follows:

[0026] 1. Tube shell; 2. Heat exchanger tube assembly; 3. Inlet header; 4. Outlet header; 11. Central column; 21. Heat exchanger tube; 22. Support baffle; 23. Mounting plate; 24. Flexible support assembly; 31. Inlet tube section; 41. Outlet tube section; 241. Tube bundle casing; 242. Compensating ring; 2421. Fixed ring; 2422. Movable ring. Detailed Implementation

[0027] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0028] Example: Figure 1 As shown, the easy-to-maintain, high-efficiency interphase spiral tube compact heat exchanger of this embodiment includes a shell 1, a heat exchange tube assembly 2, an inlet header 3, and an outlet header 4. The heat exchange tube assembly 2 includes heat exchange tubes 21. The rising and falling sections of the heat exchange tubes 21 are folded in half and spirally wound around the shell 1. Both ends of the heat exchange tubes 21 extend out of the shell 1 and are detachably connected to the inlet header 3 and the outlet header 4, respectively.

[0029] Generally, the other end of the shell 1 is open, and a central column 11 extending along its long axis is provided in the central region of one end inside the shell 1, and the heat exchange tube 21 is spirally coiled around the periphery of the central column 11.

[0030] In this embodiment, the heat exchange tube 21 adopts a folded-down section and a parallel flow method, and is spirally coiled around the periphery of the central column 11 (e.g., Figure 3 As shown in the figure, it improves upon the shortcomings of the traditional straight tube layout in the descending section of the heat exchanger, eliminating the need for a separate central downcomer. This simplifies the manufacturing process of the pool-type spiral tube heat exchanger, reduces the diameter of the central column of the spiral tube heat exchanger bundle and the heat exchange dead zone space, and increases the effective heat exchange ratio area of ​​the spiral wound tube region of the heat exchanger, resulting in a significant improvement in heat exchange efficiency.

[0031] In a preferred embodiment, the inlet manifold 3 and the outlet manifold 4 are located at the same end of the shell 1, and the two ends of the heat exchange tube 21 extend out from one end of the shell 1, respectively.

[0032] In the above implementation scheme, the entire heat exchange tube assembly is installed inside the tube shell 1 using a plug-in method. It is detachably connected to the inlet header 3 and the outlet header 4 at the same end of the tube shell 1, making the entire heat exchange tube bundle assembly easier to disassemble and assemble. Only the joints connecting the heat exchange tube 21 to the inlet header 3 and the outlet header 4 need to be removed, and the heat exchange tube assembly can be taken out from the other open end of the tube shell 1, which is very easy to maintain.

[0033] It should be noted that in this embodiment, the arrangement of the rising and falling sections of the heat exchange tube 21 in parallel flow after being folded is a "phase-to-phase" structure. The falling section of the heat exchange tube 21 refers to the section for water inlet, and the rising section refers to the section for water outlet.

[0034] In this embodiment, spiral grooves, horizontal grooves and other heat exchange enhancement structures are provided on the surface of the heat exchange tube 21, and the heat exchange tube 21 can be embedded in the matching groove.

[0035] In this embodiment, the heat exchange tube group 2 includes at least two heat exchange tubes 21.

[0036] As a preferred implementation method, such as Figure 2 As shown, the aforementioned inlet manifold 3 includes multiple arc-shaped inlet pipe sections 31, and the joints corresponding to the descending sections of the multiple aforementioned heat exchange tubes 21 are connected and communicated with any one or more of the aforementioned inlet pipe sections 31.

[0037] In the above implementation scheme, the combined structure of multiple inlet pipe sections 31 replaces the traditional inlet header of the heat exchanger, eliminating the need for large-size tube-side fluid distribution headers and pipes composed of traditional end caps, cylindrical sections, etc. A ring pipe is used as the inlet header, which is connected to the inlet end (downward section joint) of the phase-to-phase heat exchange tubes 21 respectively. According to the multi-section pipe design of the inlet header 3, the heat exchange tubes 21 can be designed as multiple heat exchange units. Each heat exchange unit is connected to one or more inlet pipe sections 31 respectively. Different media or the same media can be introduced into each inlet pipe section 31, forming a structure in which multiple different media participate in heat exchange at the same time.

[0038] In this embodiment, the multi-section inlet pipe segment 31 is provided in three sections. The heat exchange tube bundle assembly is provided with three layers (groups) of heat exchange tube groups 2, and the inlet end of the heat exchange tube 21 in each group of heat exchange tube groups 2 is respectively connected to an inlet pipe segment 31. Alternatively, the inlet ends of the heat exchange tube 21 in any two or three groups of heat exchange tube groups 2 can be respectively connected to an inlet pipe segment 31. When a heat exchange tube 21 is damaged, the heat exchange tube can be cut off or blocked directly from the annular inlet pipe segment 31, making the heat exchanger maintenance convenient.

[0039] Based on the above implementation plan, such as Figure 2 As shown, the outlet manifold 4 includes multiple arc-shaped outlet pipe sections 41 (in this embodiment, the number of outlet pipe sections 41 is the same as the number of inlet pipe sections 31), and the joints corresponding to the rising sections of multiple heat exchange tubes 21 are connected and communicated with any one or more of the outlet pipe sections 41.

[0040] In the above implementation scheme, the combined structure of multiple outlet pipe sections 41 replaces the traditional outlet header of the heat exchanger, eliminating the need for large-size tube-side fluid distribution headers and pipes composed of traditional end caps, cylinder sections, etc. The connection and distribution between the outlet end (rising section joint) of the heat exchange tube 21 and the outlet pipe section 41 can refer to the connection and distribution method between the inlet pipe section 31 and the inlet end (falling section joint) of the heat exchange tube 21. When a heat exchange tube 21 is damaged, the heat exchange tube can be cut off or plugged directly from the annular outlet pipe section 41. At the same time, the heat exchange tube can also be cut off or plugged from the inlet pipe section 41, making heat exchanger maintenance very convenient.

[0041] It is particularly important to emphasize that the ease of maintenance of this embodiment is also reflected in the design of the heat exchange tube assembly 2. The heat exchange tube assembly 2 is composed of multiple heat exchange tubes 21 spirally wound together. If the inlet or outlet interface of one of the heat exchange tubes 21 is faulty, it is only necessary to seal the joint of that heat exchange tube 21 or perform other maintenance operations, without affecting the normal use of other heat exchange tubes 21.

[0042] In a preferred embodiment, the heat exchange tube group 2 is provided in multiple groups and is distributed at intervals from the inside to the outside, and the multiple heat exchange tube groups constitute a heat exchange tube bundle assembly.

[0043] In the above implementation scheme, the multi-layer arrangement of multiple heat exchange tube groups 2 inside and outside results in higher heat exchange efficiency and a more compact arrangement between structures, which can effectively reduce the overall size of the heat exchanger.

[0044] In a preferred embodiment, a support partition 22 is provided between two adjacent heat exchange tube groups 2, and an installation plate 23 sleeved on the outside of the central column 11 is connected to the end of the support partition 22.

[0045] In the above implementation scheme, the multi-layer heat exchange tube bundles 2 are separated by support partitions 22 to prevent the heat exchange tube bundles 2 from being squeezed and damaged by each other. At the same time, the support partitions 22 are connected to the mounting plate 23 to form a whole, which makes it very easy to disassemble and repair the entire heat exchange tube bundle assembly.

[0046] In a preferred embodiment, the system further includes an elastic support component 24, which is installed around the periphery of the plurality of heat exchange tube groups 2 and elastically supported on the inner wall of the tube shell 1.

[0047] In the above implementation scheme, the elastic support component 24 serves to separate the heat exchange tube bundle 2 from the inner wall of the tube shell 1. At the same time, it also forms an elastic sliding support between the heat exchange tube bundle assembly and the tube shell 1. When the heat exchange tube bundle 2 expands due to heat, the elastic support component 24 is squeezed and deformed to prevent the heat exchange tube 21 from being deformed by heat and causing damage to the tube shell 1.

[0048] In a preferred embodiment, the elastic support assembly 24 includes a tube bundle sleeve 241 and an elastic compensation ring 242. The tube bundle sleeve 241 is fitted around the periphery of the multiple sets of heat exchange tubes 2, and the compensation ring 242 is assembled on the outside of the tube bundle sleeve 241 and contacts the inner wall of the tube shell 1.

[0049] In the above implementation scheme, the tube bundle shroud 241 can constrain the heat exchange tube bundle assembly, so that the structure can maintain a stable and compact arrangement. At the same time, the compensation ring 242 can be elastically connected to the inner wall of the tube shell 1. It deforms under pressure to prevent the heat exchange tube 21 from deforming due to heat and causing damage to the tube shell 1.

[0050] In this embodiment, the elastic compensation ring 5 is spirally wound around the periphery of the tube bundle shroud 241, so that the fluid outside the heat exchange tube bundle assembly presents a spiral flow, which enhances the disturbance of the fluid in the heat exchange tube bundle assembly.

[0051] More preferably, the longitudinal section of the compensation ring 242 is an outwardly convex arc shape, the upper end of the compensation ring 242 is connected and fixed to the outer surface of the tube bundle shroud 241, and the outwardly convex part of the compensation ring 242 is in contact with the inner wall of the tube shell 1.

[0052] In the above scheme, the raised arc shape can undergo effective deformation when subjected to compressive force, thus providing good protection for the shell 1.

[0053] More specifically, the upper end of the compensation ring 242 is connected to a fixed ring 2421 that is connected to the outer surface of the tube bundle shroud 241, and the lower end of the compensation ring 242 is connected to a movable ring 2422 that can move up and down along the outer surface of the tube bundle shroud 241.

[0054] In the above implementation scheme, the upper end of the compensation ring 242 is fixed and the lower end can slide freely. When subjected to compressive force, its convex arc-shaped part is squeezed, and its lower end can move downward along the surface of the tube bundle sleeve 241 or the inner surface of the tube shell 1 to relieve pressure. The overall design is relatively reasonable, and the arrangement structure between the tube shell 1 and the tube bundle sleeve 241 is reasonable and compact, occupying a small space volume.

[0055] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-efficiency, easily maintainable, interphase spiral tube compact heat exchanger, characterized in that: The device includes a shell (1), a heat exchange tube assembly (2), an inlet header (3), and an outlet header (4). The heat exchange tube assembly (2) includes heat exchange tubes (21). The rising and falling sections of the heat exchange tubes (21) are folded in half and spirally coiled in the shell (1). The two ends of the heat exchange tubes (21) protrude from the shell (1) and are detachably connected to the inlet header (3) and the outlet header (4), respectively. The heat exchange tube assembly (2) includes at least two heat exchange tubes (21). The inlet header (3) includes multiple arc-shaped inlet pipe sections (31). The joints corresponding to the falling sections of the multiple heat exchange tubes (21) are connected to and communicate with any one or more of the inlet pipe sections (31). The outlet header (4) includes multiple arc-shaped outlet pipe sections (41). The joints corresponding to the rising sections of the multiple heat exchange tubes (21) are connected to and communicate with any one or more of the outlet pipe sections (41).

2. The easily maintainable, high-efficiency interphase spiral tube compact heat exchanger according to claim 1, characterized in that: The inlet manifold (3) and outlet manifold (4) are located at the same end of the shell (1), and the two ends of the heat exchange tube (21) extend out from one end of the shell (1).

3. A high-efficiency, easily maintainable, interphase spiral tube compact heat exchanger according to claim 1 or 2, characterized in that: The heat exchange tube group (2) is provided in multiple groups and is distributed at intervals from the inside to the outside.

4. The easily maintainable, high-efficiency interphase spiral tube compact heat exchanger according to claim 3, characterized in that: A support partition (22) is provided between two adjacent heat exchange tube groups (2). A central column (11) extending along its long axis is provided in the central area of ​​one end of the tube shell (1). An installation plate (23) sleeved on the outside of the central column (11) is connected to the end of the support partition (22).

5. The easily maintainable, high-efficiency interphase spiral tube compact heat exchanger according to claim 3, characterized in that: It also includes an elastic support assembly (24), which is installed on the periphery of the multiple heat exchange tube groups (2) and elastically supported on the inner wall of the tube shell (1).

6. The easily maintainable, high-efficiency interphase spiral tube compact heat exchanger according to claim 5, characterized in that: The elastic support assembly (24) includes a tube bundle sleeve (241) and an elastic compensation ring (242). The tube bundle sleeve (241) is fitted around the periphery of the multiple sets of heat exchange tubes (2). The compensation ring (242) is assembled outside the tube bundle sleeve (241) and contacts the inner wall of the tube shell (1).

7. A high-efficiency, easily maintainable, interphase spiral tube compact heat exchanger according to claim 6, characterized in that: The longitudinal section of the compensation ring (242) is an outwardly convex arc shape. The upper end of the compensation ring (242) is connected and fixed to the outer surface of the tube bundle sleeve (241). The outwardly convex part of the compensation ring (242) is in contact with the inner wall of the tube shell (1).

Images