A heat exchange device

Abstract

The utility model relates to heat exchanger technical field especially relates to a heat exchange device, including the casing and set up in the coiled pipe assembly of casing, the coiled pipe assembly includes a plurality of serpentine pipes that extend along the inside space of casing and form fluid passage in proper order and are connected to bend, serpentine pipe is used for the flow of first medium, the shell side flow channel is formed between serpentine pipe and casing, is used for the flow of second medium, so that first medium and second medium carry out heat exchange through serpentine pipe wall, the outer surface of serpentine pipe is provided with a plurality of fins, and the fin is periodic distribution along the axial direction of serpentine pipe, set up on the fin is the disturbance structure, and the disturbance structure is used for producing disturbance when the shell side fluid flows through the fin, to destroy the fluid boundary layer, enhances the convection heat transfer coefficient of shell side side, through the fin and disturbance structure of periodic distribution of serpentine pipe outer surface setting, destroy the shell side fluid boundary layer while increasing the heat transfer area, effectively promote the heat exchange efficiency and reduce flow resistance, has the compact structure and the advantage of energy -conserving.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a heat exchange device. Background Technology

[0002] Heat exchangers are key equipment for heat transfer between media at different temperatures. They enable indirect heat exchange between hot and cold fluids through isolation walls, thereby achieving the purpose of heating, cooling, or energy recovery. Traditional heat exchangers typically adopt a basic structure of shell and internal heat transfer pipes, forming independent tube-side and shell-side channels. The first medium flows in the tube-side channel formed by the heat exchange tubes, while the second medium flows in the shell-side channel formed inside the shell. Energy exchange is achieved between the two through the tube walls. To increase the heat exchange area, some designs use serpentine tube structures for the heat exchange tubes.

[0003] However, traditional serpentine tubes are usually smooth circular tubes. When the shell-side fluid flows through the outer surface of the serpentine tube, a stable flow boundary layer is easily formed. The presence of this boundary layer will significantly reduce the convective heat transfer efficiency on the shell side. Especially under low flow rate conditions or when the system pressure drop is limited, the boundary layer problem is more prominent, resulting in a decrease in overall heat transfer performance. Although existing technologies have attempted to improve the heat transfer effect by increasing the flow rate or adding baffles, these methods often lead to increased system energy consumption, increased flow resistance, and difficulty in achieving efficient heat transfer in a limited space.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] This invention provides a heat exchange device, thereby effectively solving the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is: a heat exchange device, comprising: a shell and a serpentine tube assembly disposed within the shell; The serpentine assembly includes a plurality of serpentine tubes extending along the internal space of the housing and sequentially bent and connected to form a fluid channel, the serpentine tubes being used to circulate a first medium; The serpentine tube and the shell form a shell-side flow channel for the flow of the second medium, so that the first medium and the second medium can exchange heat through the serpentine tube wall; The outer surface of the serpentine tube is provided with a number of fins, which are periodically distributed along the axial direction of the serpentine tube to increase the heat transfer area. The fins are provided with a disturbance structure, which is used to generate disturbance when the shell-side fluid flows through the fins, thereby disrupting the fluid boundary layer and enhancing the convective heat transfer coefficient on the shell side.

[0007] Furthermore, the fins are spiral fins spirally wound around the serpentine tube.

[0008] Furthermore, the fins are strip-shaped structures arranged at intervals along the axial direction.

[0009] Furthermore, the serpentine tube includes several parallel straight pipe sections and an arc-shaped section that connects two adjacent straight pipe sections end to end in sequence, and the straight pipe sections are arranged perpendicular to the axis of the shell, and the fins are at least disposed on the surface of the straight pipe sections.

[0010] Furthermore, the disturbance structure is a corrugated structure disposed on the surface of the fin, the corrugated structure extending radially along the serpentine tube, used to guide the shell-side fluid to generate lateral disturbance.

[0011] Furthermore, the ripple structure is a single waveform, an intermittent waveform, or a continuous waveform, one of the following.

[0012] Furthermore, the disturbance structure is a protrusion structure or a pit structure disposed on the surface of the fin, and the protrusion structure or pit structure is distributed in a regular array on the surface of the fin.

[0013] Furthermore, the disturbance structure is a louver-type slit or hole formed by stamping on the fin.

[0014] Furthermore, the fins are welded to the serpentine tube by contact welding or laser welding.

[0015] The beneficial effects of this utility model are as follows: This utility model uses periodically distributed fins and disturbance structures on the outer surface of the serpentine tube to increase the heat transfer area while destroying the shell-side fluid boundary layer, effectively improving heat transfer efficiency and reducing flow resistance, and has the advantages of compact structure and energy saving. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the heat exchange device. Figure 2 This is a schematic diagram of the structure of a spiral fin; Figure 3 A schematic diagram of a structure with spiral fins installed only on straight pipe sections; Figure 4 A schematic diagram showing that both straight and curved sections are equipped with strip-shaped fins. Figure 5 A schematic diagram of a single-waveform disturbance structure; Figure 6 A schematic diagram of the disturbance structure for an intermittent waveform; Figure 7 A schematic diagram of the disturbance structure for a continuous waveform; Figure 8 A schematic diagram of a disturbance structure with a convex point structure; Figure 9 A schematic diagram of the disturbance structure for the pit structure; Figure 10 A schematic diagram of the disturbance structure of the pore; Reference numerals: 1. Shell; 2. Coil assembly; 21. Coil; 211. Straight section; 212. Arc section; 3. Fin; 31. Helical fin; 32. Strip structure; 33. Disturbance structure; 331. Single waveform; 332. Intermittent waveform; 333. Continuous waveform; 334. Protrusion structure; 335. Dentient structure; 336. Hole / slit. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] In the description of this utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inner", and "outer" are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not 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 utility model.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] like Figures 1 to 10 As shown: A heat exchange device includes: a housing 1 and a serpentine tube assembly 2 disposed within the housing 1; The serpentine tube assembly 2 includes several serpentine tubes 21 that extend along the internal space of the housing 1 and are sequentially bent and connected to form a fluid channel. The serpentine tubes 21 are used to circulate the first medium. A shell-side flow channel is formed between the serpentine tube 21 and the shell 1 for the flow of the second medium, so that the first medium and the second medium can exchange heat through the wall of the serpentine tube 21. The outer surface of the serpentine tube 21 is provided with several fins 3, which are periodically distributed along the axial direction of the serpentine tube 21 to increase the heat transfer area. The fin 3 is provided with a disturbance structure 33, which is used to generate disturbance when the shell-side fluid flows through the fin 3, thereby disrupting the fluid boundary layer, enhancing the convective heat transfer coefficient on the shell side, and thus improving the heat transfer efficiency.

[0022] Specifically, the serpentine tube 21 forms a continuous flow channel through bending, allowing the first medium to flow fully within the tube. When the shell-side fluid flows over the surface of the fins 3, the extended structure of the fins 3 expands the heat transfer area. At the same time, the periodically distributed fins 3 cause regular changes in the fluid flow path. When the fluid comes into contact with the disturbance structure 33, the flow direction is forced to change, forming local eddies and secondary flows, effectively disrupting the originally stable laminar boundary layer. This disturbance enhances the turbulence intensity of the shell-side fluid and increases the convective heat transfer coefficient. The combined design of the fins 3 and the disturbance structure 33 enables higher heat transfer at the same flow velocity. This solution improves efficiency while avoiding increased pressure drop due to increased flow velocity. Compared with existing technologies, traditional smooth serpentine tubes 21 rely solely on the tube wall for heat transfer, and the shell-side fluid is prone to forming a laminar boundary layer. This solution expands the heat transfer area through fins 3, significantly increasing the effective heat transfer area per unit volume. The disturbance structure 33 actively induces fluid turbulence, breaking the boundary layer without relying on increasing the flow velocity or adding guide plates. It improves heat transfer efficiency while maintaining low flow resistance. Compared with simply increasing the density or height of fins 3, the periodic distribution characteristics avoid the formation of flow dead zones and ensure uniform distribution of fluid disturbance effects.

[0023] In summary, by setting fins 3 with disturbance structures 33 on the outer surface of the serpentine tube 21, the shell-side fluid generates continuous disturbance and transverse vortices when flowing over the surface of the fins 3, effectively disrupting the originally stable flow boundary layer, thereby significantly improving the convective heat transfer coefficient on the shell side. Compared with the traditional smooth serpentine tube 21 structure, this invention not only expands the heat transfer area, but also introduces an active heat transfer enhancement mechanism at the structural level, transforming the heat transfer process from area-increasing heat transfer to disturbance-increasing heat transfer. It can significantly improve the heat transfer efficiency on the shell side without significantly increasing flow resistance and system energy consumption, and improve the thermal performance under low flow velocity or pressure drop-limited conditions, thereby achieving an overall improvement in heat transfer efficiency.

[0024] One specific embodiment of fin 3 is as follows: fin 3 is a spiral fin 313 spirally wound on the serpentine tube 21, such as... Figure 2 The diagram shows a simplified representation of the spiral fin 313. The spiral fin 313 refers to a sheet-like structure that extends around the outer surface of the serpentine tube 21 in a spiral shape. Specifically, it can be achieved by continuously winding and welding metal strips. The continuous grooves formed by the spiral winding can guide the shell-side fluid to flow in a spiral direction. In particular, the spiral fin 313 changes the flow direction of the shell-side fluid through the periodic spiral groove structure, forcing the fluid to generate rotational motion when flowing along the axial direction. This rotational motion continuously destroys the thermal boundary layer formed on the surface of the fin 3, causing the fluid micro-particles to be continuously mixed and renewed, thereby enhancing the convective heat transfer process.

[0025] Another specific embodiment of fin 3 is as follows: fin 3 is a strip-shaped structure 32 arranged at intervals along the axial direction, such as... Figure 3 , 4 As shown, the fins 3 of the strip structure 32 are periodically arranged on the surface of the serpentine tube 21. The strip structure 32 refers to a metal sheet with a long strip geometry. Specifically, it can be formed by stamping metal strips with rectangular, trapezoidal or wavy cross sections and fixed to the surface of the serpentine tube 21 by welding. Specifically, the strip fins 3 are arranged parallel to each other along the axial direction of the serpentine tube 21, and a longitudinal gap is formed between adjacent fins 3. When the shell-side fluid flows through the gap of the fins 3, periodic flow separation and reattachment occur at the edge of the strip fins 3, forming local turbulence. This intermittent arrangement causes the fluid to repeatedly experience acceleration and deceleration during axial flow, and the boundary layer is continuously damaged. Compared with the continuous spiral fins 313, the strip fins 3, while maintaining the heat transfer area, guide the fluid to generate lateral flow through the gaps, increasing the tortuosity of the flow path.

[0026] As a preferred embodiment of the above, the serpentine tube 21 includes a plurality of parallel straight tube segments 211 and an arc-shaped segment 212 that connects two adjacent straight tube segments 211 end to end. The straight tube segments 211 are perpendicular to the axis of the housing 1, and fins 3 are at least disposed on the surface of the straight tube segments 211. (Refer to...) Figure 3 Only the straight pipe section 211 is provided with fins 3, which facilitates processing. The fins 3 are concentrated on the surface of the straight pipe section 211, which can expand the heat transfer area in areas with high fluid velocity and stable flow direction. At the same time, combined with the spatial relationship between the straight pipe section 211 and the shell 1, the flow distribution of the shell-side fluid is further optimized; in another embodiment, such as Figure 4 As shown, fins 3 are simultaneously disposed on the outer surfaces of both the straight pipe section 211 and the curved section 212. This structure can also provide additional heat transfer area in the fluid turning region, allowing the shell-side fluid to form stronger flow disturbances and local eddies at the bends, thereby enhancing the convective heat transfer capacity of this region. By comparison, it can be seen that the scheme of setting fins 3 only in the straight pipe section 211 has the advantages of simple structure and low manufacturing cost, while the scheme of setting fins 3 in both the straight pipe section 211 and the curved section 212 is superior in terms of overall heat transfer performance. In practical applications, different fin arrangement methods can be selected according to the flow state of the working medium and the heat transfer requirements to achieve the best balance between processing cost and heat transfer efficiency.

[0027] like Figures 5 to 7 As shown, a specific implementation of the disturbance structure 33 is as follows: The disturbance structure 33 is a corrugated structure disposed on the surface of the fin 3. The corrugated structure extends radially along the serpentine tube 21 and is used to guide the shell-side fluid to generate lateral disturbance. Specifically, the corrugated structure forms regular undulations on the surface of the fin 3. When the shell-side fluid flows through the fin 3, the undulations of the corrugations force the fluid to generate a lateral flow component, thereby forming a disturbance perpendicular to the flow direction outside the mainstream direction. The periodic distribution of the corrugations allows the fluid to be continuously guided laterally during the flow along the fin 3, and the boundary layer is repeatedly destroyed and reformed, avoiding the stable development of the laminar boundary layer. The extension direction of the corrugations is consistent with the radial direction of the serpentine tube 21, so that the fluid can cover a larger area of ​​the fin 3 surface during the lateral disturbance, thereby enhancing the contact efficiency between the fluid and the fin 3.

[0028] As a preferred embodiment of the above, the corrugated structure is a single waveform 331, an intermittent waveform 332, or a continuous waveform 333, one of which is referred to. Figure 5 The cross-section of the waveform structure is a single waveform 331; reference Figure 6 The cross-section of the waveform structure is an intermittent waveform 332; Reference Figure 7The cross-section of the waveform structure is a continuous waveform 333. Specifically, the corrugated structure creates lateral disturbances in the direction of fluid flow in the shell side through its wave-like undulations. When the fluid flows through the crests and troughs of the corrugated structure, the flow direction is forced to deflect periodically, generating a lateral secondary flow. This secondary flow can disrupt the originally stable fluid boundary layer, causing the low-speed fluid in the boundary layer to mix with the mainstream high-speed fluid, thereby enhancing the convective heat transfer intensity on the shell side. The single waveform 331 structure is suitable for low flow rate conditions, generating disturbances through a single crest and trough. The intermittent waveform 332 maintains the disturbance effect while reducing flow resistance through spaced wave segments. The continuous waveform 333 forms continuous disturbances under high flow rate conditions through a densely arranged wave sequence.

[0029] A second specific implementation of the disturbance structure 33 is as follows: the disturbance structure 33 is a protrusion structure 334 or a recess structure 335 disposed on the surface of the fin 3, and the protrusion structure 334 or the recess structure 335 is distributed in a regular array on the surface of the fin 3, such as... Figure 8 As shown, the disturbance structure 33 is a protrusion structure 334 disposed on the surface of the fin 3. This type of structure forms microscale geometric undulations on the surface of the fin 3, causing periodic disturbances to the fluid as it flows through the fin 3, thereby breaking the stable boundary layer of the shell-side fluid and increasing the flow energy and heat transfer intensity in the near-wall region; as Figure 9 As shown, the disturbance structure 33 is a recessed structure 335 disposed on the surface of the fin 3. The recessed structure 335 can be formed by stamping or etching, and its shape can be spherical, bowl-shaped, or polygonal cross-section. Spherical recesses are preferred to obtain smooth flow transition characteristics. In summary, both the convex structure 334 and the recessed structure 335 can effectively enhance the turbulence of the shell-side fluid and improve the convective heat transfer capacity of the shell side without significantly increasing the flow resistance. In comparison, the convex structure 334 has a stronger disturbance effect under medium and high flow rate conditions and is suitable for situations with high fluid Reynolds numbers. The recessed structure 335 exhibits better stability and energy saving under low flow rate or high viscosity conditions. By rationally selecting the shape and distribution parameters of the disturbance structure 33, the present invention can achieve an optimized balance between efficient heat exchange and low energy consumption operation in different application scenarios.

[0030] like Figure 10 As shown, the third specific implementation of the disturbance structure 33 is as follows: the disturbance structure 33 is a louver-type slot or perforation 336 formed by stamping on the fin 3. Specifically, when the shell-side fluid flows through the fin 3, the inclined cut of the louver-type slot will force the fluid to change its flow direction and form a transverse shear flow; while the perforation 336 structure will generate a vortex region behind the hole. Both of these flow states can continuously destroy the fluid boundary layer formed on the surface of the fin 3, keep the shell-side fluid in a turbulent state, and thus enhance the convective heat transfer efficiency.

[0031] As a preferred embodiment of the above, the fins 3 and the serpentine tube 21 are welded by contact welding or laser welding. Contact welding refers to a welding method that uses the resistance heat generated by the current passing through the metal contact surface to melt or soften the local metal, and then applies pressure to form a connection. Specifically, it can be achieved by resistance spot welding or seam welding. Laser welding is a welding technology that uses a high-power laser beam as a heat source. In laser welding, the laser beam is focused on the joint surface of the fins 3 and the serpentine tube 21, and the metal at the contact surface is rapidly melted by the high temperature to form a weld pool. As the laser beam moves, the weld pool cools and solidifies rapidly, ultimately forming a welded joint with high strength. Laser welding has a small heat-affected zone and precise thermal control, which can achieve high-quality welding. It is especially suitable for welding applications with complex shapes and high precision requirements. Both processes can achieve metallurgical bonding between the surfaces of the fins 3 and the serpentine tube 21, prevent welding gaps between the fins 3 and the serpentine tube 21, and ensure the continuity of the heat transfer path.

[0032] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A heat exchange device, characterized in that, include: Housing and snake tube assembly disposed within the housing; The serpentine assembly includes a plurality of serpentine tubes extending along the internal space of the housing and sequentially bent and connected to form a fluid channel, the serpentine tubes being used to circulate a first medium; The serpentine tube and the shell form a shell-side flow channel for the flow of the second medium, so that the first medium and the second medium can exchange heat through the serpentine tube wall; The outer surface of the serpentine tube is provided with a number of fins, which are periodically distributed along the axial direction of the serpentine tube to increase the heat transfer area. The fins are provided with a disturbance structure, which is used to generate disturbance when the shell-side fluid flows through the fins, thereby disrupting the fluid boundary layer and enhancing the convective heat transfer coefficient on the shell side.

2. The heat exchange device according to claim 1, characterized in that, The fins are spiral fins wound around the serpentine tube.

3. The heat exchange device according to claim 1, characterized in that, The fins are strip-shaped structures arranged at intervals along the axial direction.

4. The heat exchange device according to claim 1, characterized in that, The serpentine tube includes several parallel straight pipe sections and an arc-shaped section that connects two adjacent straight pipe sections end to end. The straight pipe sections are perpendicular to the axis of the shell, and the fins are at least disposed on the surface of the straight pipe sections.

5. The heat exchange device according to claim 1, characterized in that, The disturbance structure is a corrugated structure disposed on the surface of the fin, which extends radially along the serpentine tube and is used to guide the shell-side fluid to generate lateral disturbance.

6. The heat exchange device according to claim 5, characterized in that, The ripple structure can be a single waveform, an intermittent waveform, or a continuous waveform, one of the following:

7. The heat exchange device according to claim 1, characterized in that, The disturbance structure is a protrusion structure or a pit structure disposed on the surface of the fin, and the protrusion structure or pit structure is distributed in a regular array on the surface of the fin.

8. The heat exchange device according to claim 1, characterized in that, The disturbance structure is a louver-type slit or hole formed by stamping on the fin.

9. The heat exchange device according to claim 1, characterized in that, The fins are welded to the serpentine tube by contact welding or laser welding.

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