A combined heat exchanger

Abstract

The utility model relates to heat exchanger technical field especially relates to a combined heat exchanger, including shell and setting in the shell's coiled pipe bundle component and coil pipe component, coiled pipe bundle component is located the center area of shell, including at least one continuous bending's coiled pipe, coil pipe component is located between the shell inner wall and the periphery of coiled pipe bundle component, including at least one continuous coiling formation's coil pipe constitutes, and along shell axis direction forms multilayer spiral structure, and the both ends of coiled pipe bundle component and coil pipe component are communicated with the pipe -side import and export respectively, to supply first medium circulation, and the shell -side flow channel is formed between the both and shell inner wall, is used for second medium flow, makes two kinds of medium heat exchange through the pipe wall, and every coiled pipe or coil pipe is equivalent to a separate heat exchange unit, and this integrated structure can realize multistage heat exchange in single equipment, reduces equipment quantity and simplifies system layout, reduces cost, and promotes heat exchange efficiency.

Description

Technical Field

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

[0002] Heat exchangers, as a general-purpose process equipment for transferring heat between two or more fluids, are widely used in many industrial fields such as petroleum, chemical, power, and metallurgy. Their core performance indicators are heat exchange efficiency, operational reliability, and maintenance economy. Among the many types of heat exchange equipment, shell-and-tube heat exchangers have become the mainstream choice in industrial applications due to their advantages such as robust structure, strong adaptability, and high pressure resistance. The BXM type heat exchanger, as a typical shell-and-tube heat exchanger, met basic industrial needs during a specific historical period.

[0003] However, existing BXM heat exchangers, due to the use of multiple units in series, result in high system flow resistance, increased energy consumption, severe medium flow deviation, reduced heat exchange efficiency, and an increased number of headers and external piping between equipment, which can easily lead to leaks.

[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 combined heat exchanger, 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 combined heat exchanger, comprising: a shell, and a serpentine tube bundle assembly and a coil assembly disposed within the shell; The shell is provided with a shell-side inlet and a shell-side outlet at both ends, and the sidewall is provided with a tube-side inlet and a tube-side outlet. The serpentine tube bundle assembly is disposed in the internal central region of the housing and includes at least one tube continuously bent into a serpentine shape. The coil assembly is coiled between the outer periphery of the serpentine tube bundle assembly and the inner wall of the housing, including at least one continuously coiled coil, and forming a multi-layered spiral structure along the axial direction of the housing. The two ends of the serpentine tube bundle assembly and the coil assembly are respectively connected to the tube inlet and the tube outlet to allow the first medium to flow. The serpentine tube assembly, the coil assembly, and the inner wall of the housing form a shell-side flow channel for the flow of the second medium, so that the first medium flowing through the serpentine tube and the coil exchanges heat with the second medium flowing through the shell-side flow channel through the tube walls of the serpentine tube and the coil.

[0007] Furthermore, the serpentine tube bundle assembly includes multiple parallel serpentine tubes, which are arranged in multiple layers in parallel on a plane projection perpendicular to the axis of the housing. The coil assembly includes multiple layers of coaxially wound coils, which divide the housing and the serpentine tube bundle assembly into multiple annular sections.

[0008] Furthermore, the serpentine tubes arranged in multiple parallel layers have equal widths.

[0009] Furthermore, the projection width of the serpentine tubes arranged in multiple layers on a plane perpendicular to the axis of the shell gradually decreases from the innermost layer to the outermost layer.

[0010] Furthermore, the diameter of the serpentine tube gradually increases from the serpentine tube with a larger projected distribution width to the serpentine tube with a smaller projected distribution width.

[0011] Furthermore, the bending density of the serpentine tube gradually increases from the serpentine tube with a larger projected distribution width to the serpentine tube with a smaller projected distribution width.

[0012] Furthermore, the pitch of the coil closer to the serpentine assembly is smaller than the pitch of the coil farther from the serpentine assembly.

[0013] Furthermore, the diameter of the coil closer to the serpentine assembly is larger than the diameter of the coil farther from the serpentine assembly.

[0014] Furthermore, the pitch of the coil along the axial direction of the shell is gradually distributed, and the pitch in the shell-side inlet region is smaller than the pitch in the shell-side outlet region.

[0015] Furthermore, the outer wall of the coil is provided with fins, which are either spirally wound metal strips or sheet-like fins extending radially from the tube wall.

[0016] The beneficial effects of this utility model are as follows: Each serpentine tube or coil in this utility model is equivalent to an original independent heat exchange device. Through this integrated design, a multi-stage heat exchange process can be realized in a single device, which greatly reduces the number of devices and piping, thereby simplifying the system layout, reducing installation costs and reducing potential leakage points, and achieving synergistic improvement in medium flow path optimization and heat exchange efficiency. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the structure of a combined heat exchanger; Figure 2 This is a schematic diagram of a first specific embodiment of a serpentine tube arrangement; Figure 3 This is a schematic diagram of a second specific embodiment of the serpentine tube arrangement; Figure 4 This is a schematic diagram of a third specific implementation of a serpentine tube arrangement; Figure 5 This is a schematic diagram of a first specific implementation of the coil arrangement; Figure 6 This is a schematic diagram of a second specific implementation of the coil arrangement; Figure 7 This is a schematic diagram of a third specific implementation of the coil arrangement.

[0019] Reference numerals: 1. Shell; 11. Shell-side inlet; 12. Shell-side outlet; 13. Tube-side inlet; 14. Tube-side outlet; 2. Serpentine tube bundle assembly; 21. Serpentine tube; 3. Coil assembly; 31. Coil; 01, First medium; 02, Second medium. Detailed Implementation

[0020] 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.

[0021] 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.

[0022] 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.

[0023] like Figures 1 to 7 As shown: A combined heat exchanger includes: a shell 1, and a serpentine tube bundle assembly 2 and a coil assembly 3 disposed within the shell 1; The shell 1 has a shell-side inlet 11 and a shell-side outlet 12 at both ends, and a tube-side inlet 13 and a tube-side outlet 14 on the side wall; The serpentine tube bundle assembly 2 is disposed in the internal central region of the housing 1, and includes at least one serpentine tube 21 continuously bent into shape; The coil assembly 3 is coiled between the outer periphery of the serpentine tube bundle assembly 2 and the inner wall of the housing 1, including at least one continuously coiled coil 31, and forming a multi-layered spiral structure along the axial direction of the housing 1. The two ends of the serpentine tube bundle assembly 2 and the coil assembly 3 are connected to the tube inlet 13 and the tube outlet 14 respectively, so as to allow the first medium 01 to flow. The serpentine tube bundle assembly 2, the coil assembly 3 and the inner wall of the shell 1 form a shell-side flow channel for the flow of the second medium 02, so that the first medium 01 flowing through the serpentine tube 21 and the coil 31 and the second medium 02 flowing through the shell-side flow channel exchange heat through the tube walls of the serpentine tube 21 and the coil 31.

[0024] By integrating the serpentine tube bundle assembly 2 and the coil assembly 3 into a composite structure, a two-stage heat exchange system is formed within a single shell 1. The shell 1 is configured with shell-side inlet and outlet and side-wall tube-side inlet and outlet at both ends, achieving independent flow channels and cross-heat exchange for the two media. The serpentine tube bundle assembly 2 is placed in the central region of the shell 1, utilizing its continuous bending structure to form a high-density heat exchange surface. Simultaneously, the coil assembly 3 employs a multi-layered spiral structure surrounding the serpentine tube bundle assembly 2, expanding the heat exchange area and creating a radial gradient flow field. The parallel connection of the serpentine tube bundle assembly 2 and the coil assembly 3 with the tube-side inlet and outlet allows the first medium 01 to be split between two different flow channel configurations, enhancing the turbulence effect. Specifically, the serpentine tube 21 is formed by sequentially bending multiple straight and bent sections, while the coil 31 is continuously coiled into a spiral structure along the axial direction. Both flow channels have significant curvature and directional changes. Under the same total flow rate, the first... After medium 01 enters the serpentine tube 21 and coil 31 respectively, the cross-sectional area of ​​the branch is relatively small, the local flow velocity is increased, and the secondary flow and vortex structure are formed by centrifugal force at the bend. This causes the fluid near the tube wall to be continuously carried away from the boundary layer and mixed with the mainstream region, thereby increasing the effective Reynolds number and the intensity of fluid disturbance. On the other hand, the continuous secondary flow and shearing effect induced by the serpentine and helical bending geometry promote the repeated breaking and renewal of the temperature boundary layer and velocity boundary layer, which significantly enhances the turbulence degree and convective heat transfer capacity of the first medium 01. The shell-side flow channel is formed in the three-dimensional space between the serpentine tube bundle assembly 2, the coil assembly 3 and the shell wall, which promotes the second medium 02 to generate a composite flow of helical propulsion and radial penetration. This integrated structural design not only eliminates the need for multiple devices to be connected in series, but also achieves the optimization of the medium flow path and the synergistic improvement of heat transfer efficiency through the spatial coupling of the dual-form heat transfer surface.

[0025] Each serpentine tube 21 or coil 31 is theoretically equivalent to an original independent heat exchange device. Through this integrated design, multi-stage heat exchange processes can be achieved within a single device, significantly reducing the number of devices and piping, thereby simplifying system layout, reducing installation costs, and reducing potential leak points.

[0026] By employing a structure that combines a central serpentine tube bundle assembly 2 and an outer coil assembly 3 inside the housing 1, the problem of the coil 31 being unable to be smoothly coiled due to the limited space in the center of the housing is solved.

[0027] Specifically, such as Figure 1As shown, the serpentine tube 21 assembly and the coil assembly 3 are simplified for illustration. There are two serpentine tubes 21 and two coils 31, which are formed by continuously bending two tubes. Then, the serpentine tubes 21 after being bent on both sides are assembled in a staggered and intersecting manner to increase the assembly rigidity between the serpentine tubes 21. Of course, the two serpentine tubes 21 can also not intersect, that is, the two serpentine tubes 21 in one plane are assembled with a certain distance between them, or only one tube is continuously bent into a wider serpentine tube 21, etc. Of course, other numbers of serpentine tubes 21 or coils 31 can also be used, all of which are within the protection scope of this application.

[0028] As a preferred embodiment of the above, the serpentine tube bundle assembly 2 includes a plurality of parallel serpentine tubes 21, which are arranged in multiple layers in parallel on a plane projection perpendicular to the axis of the housing 1. The coil assembly 3 includes a coaxially wound multi-layered coil 31, which divides the housing 1 and the serpentine tube bundle assembly 2 into multiple annular sections. Specifically, as shown... Figure 2 As shown, five layers of serpentine tubes 21 are arranged side by side, and two layers of coils 31 are also shown. The specific number of layers of serpentine tubes 21 and coils 31 can be set according to the size and requirements of the shell 1. By setting multiple parallel serpentine tubes 21 inside the shell 1 and forming multiple layers of side by side, the serpentine tube bundle assembly 2 forms a layered and partitioned arrangement in the radial direction, making the flow path of the first medium 01 in each serpentine tube 21 more uniform, thereby realizing multi-channel parallel heat exchange and improving the heat transfer efficiency and fluid distribution balance on the tube side. At the same time, the coil assembly 3 adopts a multi-layer coaxial winding arrangement, arranged in layers along the axial direction of the shell 1, forming multiple annular intervals on the outer periphery of the serpentine tube bundle assembly 2, so that the second medium 02 is in a layered flow state in the shell side. The coaxial layered structure not only effectively increases the heat exchange area, but also makes the shell side fluid form a composite flow in the radial and axial directions, improving the fluid disturbance intensity and local heat transfer coefficient.

[0029] Continue to refer to Figure 2 The first specific implementation of the serpentine tube 21 arrangement is as follows: the serpentine tubes 21 arranged in multiple parallel layers have equal distribution widths. The equal width distribution structure helps to standardize the processing and assembly, so that the serpentine tube bundle assembly 2 can be manufactured in a modular manner, which simplifies the manufacturing and assembly process.

[0030] A second specific implementation of the serpentine tube arrangement 21 is as follows: the serpentine tubes 21 arranged in multiple layers, with their projection width on a plane perpendicular to the axis of the shell 1, gradually decreases from the innermost layer to the outermost layer, such as... Figure 3 As shown, the middle serpentine tube 21 has the longest width, while the serpentine tubes 21 on both sides gradually shorten, realizing a gradually shrinking arrangement of the serpentine tubes 21. This achieves a high-density tube bundle layout within the limited space of the shell 1, increasing the heat exchange area and improving the heat transfer efficiency.

[0031] like Figure 4 As shown, the third specific implementation of the serpentine tube 21 arrangement is as follows: the diameter of the serpentine tube 21 with a larger projected distribution width gradually increases from the serpentine tube 21 with a smaller projected distribution width. Specifically, since the space occupied by the outer serpentine tube 21 is relatively compact, its arrangement width may lead to a reduction in the cross-sectional area of ​​the flow channel inside the tube, an increase in flow velocity, and an increase in pressure drop. By appropriately increasing the diameter of the outer serpentine tube 21, the reduction in the flow cross-sectional area can be effectively compensated, so that the fluid flow velocity in each layer of serpentine tube 21 remains relatively balanced, reducing the difference in local flow resistance, thereby improving the overall flow distribution. This not only helps to reduce the pressure drop along the pipe, but also prevents the formation of high flow velocity and energy consumption concentration areas in the outer channel.

[0032] The fourth specific implementation of the serpentine tube arrangement 21 is as follows: the bending density gradually increases from the serpentine tube 21 with a larger projected distribution width to the serpentine tube 21 with a smaller projected distribution width. Specifically, the outer serpentine tube 21 has more bending sections within the same length range, which can effectively extend the fluid flow path when the outer space is relatively compact, increase the degree of turbulence and the frequency of fluid disturbance in the tube, thereby improving the convective heat transfer coefficient. In addition, the increase in bending density also increases the heat transfer area per unit length of the outer serpentine tube 21, making up for the insufficient heat transfer area caused by the reduction in the width of the outer layer arrangement. Through the gradual design of the bending density of the inner and outer layers, the entire serpentine tube bundle assembly 2 forms a gradually enhanced heat transfer structure in the radial direction, so that the fluid heat transfer capacity of different levels matches the space utilization rate.

[0033] like Figure 5 As shown, the first specific implementation of the coil 31 arrangement is as follows: the pitch of the coil 31 closer to the serpentine tube 21 assembly is smaller than the pitch of the coil 31 farther away from the serpentine tube 21 assembly, so that the coil 31 is arranged in a spiral pattern with the inner coil being tighter and the outer coil being looser in the radial direction. This makes the length of the inner and outer coils 31 basically consistent. Since the radius of the outer coil 31 is larger, its circumferential length per turn increases. By appropriately increasing the pitch, the extension length of the inner and outer coils 31 in the axial direction can be compensated, thereby maintaining the overall flow path length balance. This makes the residence time of the first medium 01 in each layer of coil 31 approximately consistent, improving the heat transfer uniformity and avoiding the problems of local overheating or insufficient heat exchange.

[0034] like Figure 6As shown, the second specific implementation of the coil 31 arrangement is as follows: the diameter of the coil 31 closer to the serpentine tube 21 assembly is larger than the diameter of the coil 31 farther away from the serpentine tube 21 assembly. Specifically, the inner coil 31 has a smaller spiral radius and its winding length is shorter than that of the outer coil 31. In order to compensate for the shortcomings of the inner coil 31 in length and heat exchange area, by appropriately increasing the diameter of the inner coil 31, its flow cross-sectional area and tube wall heat exchange area can be increased within a limited length range, thereby improving its heat exchange capacity per unit length and thus achieving a balanced match with the outer coil 31 in heat transfer performance. In addition, increasing the diameter of the inner coil 31 can also reduce its flow resistance and prevent the problem of excessive fluid velocity or pressure drop in the inner region. At the same time, the increased diameter can improve mechanical strength and vibration resistance, making the overall structure of the coil 31 more stable and reliable. It can achieve a comprehensive effect of fluid velocity balance, consistent heat exchange capacity and enhanced structural strength within the limited space of the shell 1.

[0035] like Figure 7 As shown, the third specific implementation of the coil 31 arrangement is as follows: the pitch of the coil 31 along the axial direction of the shell 1 is gradually distributed. The pitch of the shell-side inlet 11 region is smaller than the pitch of the shell-side outlet 12 region. Specifically, when the second medium 02 enters from the shell-side inlet 11, its temperature is lower and the temperature difference with the first medium 01 in the tube is larger. In order to make full use of the initial temperature difference for efficient heat exchange, a smaller pitch is adopted in the inlet region, making the coil 31 more densely distributed and the local flow channel narrower, thereby increasing the fluid disturbance and turbulence, and improving the initial heat transfer coefficient. As the fluid gradually heats up along the axial direction and the temperature difference decreases, the pitch of the outlet region increases and the flow channel gradually widens, which can reduce the flow resistance, balance the pressure drop and maintain a moderate flow velocity distribution, so that the second medium 02 maintains a high heat transfer efficiency throughout the entire flow path.

[0036] As a preferred embodiment of the above, the outer wall of the coil 31 is provided with fins (not shown). The fins are either spirally wound metal strips or sheet-like fins extending radially from the tube wall. Specifically, by providing fins on the outer wall of the coil 31, the heat transfer contact area between the coil 31 and the shell-side fluid is increased, thereby improving the heat transfer efficiency on the shell side. The fins can be spirally wound metal strip structures or sheet-like fins extending radially along the tube wall. Both forms can create additional disturbances when the fluid flows through the outer surface of the coil 31, causing the fluid boundary layer to continuously break and regenerate, thereby enhancing the convective heat transfer effect.

[0037] 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 combined heat exchanger, characterized in that, Includes: a housing, and a serpentine tube bundle assembly and a coil assembly disposed within the housing; The shell is provided with a shell-side inlet and a shell-side outlet at both ends, and the sidewall is provided with a tube-side inlet and a tube-side outlet. The serpentine tube bundle assembly is disposed in the internal central region of the housing and includes at least one tube continuously bent into a serpentine shape. The coil assembly is coiled between the outer periphery of the serpentine tube bundle assembly and the inner wall of the housing, including at least one continuously coiled coil, and forming a multi-layered spiral structure along the axial direction of the housing. The two ends of the serpentine tube bundle assembly and the coil assembly are respectively connected to the tube inlet and the tube outlet to allow the first medium to flow. The serpentine tube assembly, the coil assembly, and the inner wall of the housing form a shell-side flow channel for the flow of the second medium, so that the first medium flowing through the serpentine tube and the coil exchanges heat with the second medium flowing through the shell-side flow channel through the tube walls of the serpentine tube and the coil.

2. The combined heat exchanger according to claim 1, characterized in that, The serpentine tube bundle assembly includes multiple parallel serpentine tubes, which are arranged in multiple layers in parallel on a plane projection perpendicular to the axis of the shell. The coil assembly includes multiple layers of coaxially wound coils, which divide the housing and the serpentine tube bundle assembly into multiple annular sections.

3. The combined heat exchanger according to claim 2, characterized in that, The serpentine tubes arranged in multiple parallel layers have equal widths.

4. The combined heat exchanger according to claim 2, characterized in that, The projection width of the serpentine tubes arranged in multiple layers on a plane perpendicular to the axis of the shell gradually decreases from the innermost layer to the outermost layer.

5. The combined heat exchanger according to claim 4, characterized in that, The diameter of the serpentine tube gradually increases from the serpentine tube with a larger projected distribution width to the serpentine tube with a smaller projected distribution width.

6. The combined heat exchanger according to claim 4 or 5, characterized in that, The bending density of the serpentine tube gradually increases from the serpentine tube with a larger projected distribution width to the serpentine tube with a smaller projected distribution width.

7. The combined heat exchanger according to claim 1, characterized in that, The pitch of the coil closer to the serpentine assembly is smaller than the pitch of the coil farther from the serpentine assembly.

8. The combined heat exchanger according to claim 1, characterized in that, The diameter of the coil closer to the serpentine assembly is larger than the diameter of the coil farther away from the serpentine assembly.

9. The combined heat exchanger according to claim 1, characterized in that, The pitch of the coil along the axis of the shell is gradually distributed, and the pitch in the shell-side inlet region is smaller than the pitch in the shell-side outlet region.

10. The combined heat exchanger according to claim 1, characterized in that, The outer wall of the coil is provided with fins, which are either spirally wound metal strips or sheet-like fins extending radially from the tube wall.

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