A coil heat exchanger

Abstract

The utility model relates to heat exchanger technology especially relates to a coil heat exchanger, including shell and the coil assembly of setting in the shell, shell both ends are equipped with shell side import and shell side export, and the lateral wall is equipped with pipe side import and pipe side export, the coil assembly includes at least one multilayer spiral coil that is formed along the shell axis continuous coiling, and the both ends of coil are communicated with pipe side import and export respectively, and the first medium is circulated, the shell side flow channel is formed between coil and shell inner wall, and the second medium is flowed, so that the first medium that flows in the coil and the second medium that flow through the shell side flow channel carry out heat exchange through the pipe wall of coil, form multilayer spiral heat exchange channel in single shell, replace traditional multiple series equipment, reduce system flow resistance and energy consumption, realize even fluid distribution and compact layout, have the advantages such as high heat exchange efficiency, compact structure.

Description

Technical Field

[0001] This utility model relates to heat exchanger technology, and more particularly to a coil heat exchanger. Background Technology

[0002] A heat exchanger is a device used to achieve heat exchange between two or more fluids. It is widely used in chemical, energy, HVAC, food and other fields. Existing BXM type heat exchangers mostly adopt the method of multiple devices connected in series and cross-flow arrangement, relying on multi-channel structure to enhance heat transfer effect.

[0003] However, connecting multiple devices in series increases the overall flow resistance of the system, leading to increased energy consumption and turbulent flow field, which can easily cause leakage and flow deviation, reducing the effective heat transfer efficiency. In addition, connecting multiple devices in series requires a large number of external headers and control pipelines, increasing the risk of leakage and installation 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 coil 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 coil heat exchanger, comprising: a shell and a coil assembly disposed within the shell; The shell has a shell-side inlet and a shell-side outlet at both ends, and the shell has a tube-side inlet and a tube-side outlet on its sidewall. The coil assembly includes at least one continuously wound coil, each coil forming a multi-layered spiral structure along the axial direction of the housing. Each of the coils is connected at both ends to the tube inlet and the tube outlet, respectively, for the flow of the first medium; A shell-side flow channel for the flow of a second medium is formed between the coil assembly and the inner wall of the housing, so that the first medium flowing through the coil and the second medium flowing through the shell-side flow channel exchange heat through the coil wall.

[0007] Furthermore, the coil assembly includes multiple coils arranged coaxially along the housing axis in several layers, the layers dividing the interior of the housing into multiple annular sections and a central circular section.

[0008] Furthermore, the layers are arranged at equal radial intervals.

[0009] Furthermore, the radial spacing between each of the aforementioned levels gradually decreases from the inside out.

[0010] Furthermore, the pitch of the coil closer to the housing axis is smaller than the pitch of the coil farther from the housing axis.

[0011] Furthermore, the spiral directions of the coils in adjacent layers are set in the same direction.

[0012] Furthermore, the spiral directions of the coils in adjacent layers are arranged in opposite directions.

[0013] Furthermore, the cross-sectional shape of the coil is circular or elliptical, at least one of the following.

[0014] The beneficial effects of this utility model are as follows: This utility model replaces the traditional multiple series-connected equipment by using a multi-layer spiral coil assembly formed by continuous winding. Each layer of spiral coil is equivalent to a single device in principle, forming an efficient heat exchange channel within a single housing, effectively reducing system flow resistance and energy consumption, while achieving uniform fluid distribution and compact layout. It has the advantages of reducing flow resistance, reducing energy consumption, improving heat exchange efficiency, and optimizing equipment compactness. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a schematic diagram of the coil assembly and shell of a coil heat exchanger. Figure 2 This is a schematic diagram of a coil heat exchanger. Figure 3 This is a schematic diagram of the first specific implementation method for arranging the various levels; Figure 4 This is a schematic diagram of a second specific implementation method for arranging the levels; Figure 5 This is a schematic diagram of a third specific implementation method for arranging the levels; Figure 6 This is a schematic diagram illustrating one specific implementation method for arranging adjacent levels. Figure 7 This is a schematic diagram of another specific implementation of the arrangement between adjacent levels.

[0017] Reference numerals: 1. Coil assembly; 11. Coil; 12. Level; 121. Annular section; 122. Circular section; 2. Shell; 21. Shell-side inlet; 22. Shell-side outlet; 23. Tube-side inlet; 24. Tube-side outlet; 01, First medium; 02, Second medium. 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 7 As shown: A coil heat exchanger includes: a housing 2 and a coil assembly 1 disposed within the housing 2; Shell side inlet 21 and shell side outlet 22 are respectively provided at both ends of shell 2, and tube side inlet 23 and tube side outlet 24 are provided on the side wall of shell 2; The coil assembly 1 includes at least one continuously wound coil 11, each coil 11 forming a multi-layered spiral structure along the axial direction of the housing 2; Each coil 11 is connected at both ends to the tube inlet 23 and the tube outlet 24 respectively, for the flow of the first medium 01; A shell-side flow channel for the flow of the second medium 02 is formed between the coil assembly 1 and the inner wall of the housing 2, so that the first medium 01 flowing through the coil 11 and the second medium 02 flowing through the shell-side flow channel can exchange heat through the wall of the coil 11.

[0022] Among them, the continuously coiled coil 11 refers to a multi-layer structure formed by spirally extending a single tube along the axial direction, such as... Figure 1 As shown, two tubes are bent into coils 11 of different diameters and then concentrically nested together. The number of coils 11 in the figure is only for illustration. More coils 11 can also be used concentrically nested according to the shell size, all of which are within the protection scope of this application. The multi-layer spiral structure refers to the formation of multiple coaxial spiral layers in the axial direction of the coil 11. The layer division can be achieved by adjusting the winding radius, thereby increasing the effective heat exchange area in a limited space.

[0023] Specifically, the first medium 01 enters the coil 11 from the tube-side inlet 23, flows along a spiral path through the multi-layer structure, and finally exits from the tube-side outlet 24. The second medium 02 enters the shell 2 from the shell-side inlet 21 and flows along the outer surface of the coil 11 within the shell-side flow channel, forming an alternating flow heat transfer mode with the first medium 01 inside the coil 11. Because the coil 11 adopts a continuous spiral structure, the flow directions and velocity gradients of the two media are mutually coordinated. Specifically, the first medium 01 inside the coil 11 has both axial and circumferential velocities as it flows along the spiral path, and its flow direction changes continuously in the axial direction of the coil; while the flow direction outside the coil 11... The second medium 02 scours the outer surface of the coil in a direction that is basically perpendicular or tangential to the axis of the coil 11, causing the two media to form multiple intersecting relative flow directions near the wall of the coil 11. Due to the spiral structure, the velocity distribution of the fluid inside and outside the coil 11 changes continuously. The fluid near the wall is continuously carried away from the wall and mixed with the mainstream area, thus maintaining a large velocity gradient and shearing effect near the wall of the coil 11. The boundary layer disturbance is enhanced. The multi-layer arrangement of the coil 11 increases the heat exchange area by a factor of two, improving the heat exchange efficiency. The single-shell structure avoids the additional flow resistance caused by multiple devices connected in series.

[0024] By integrating a multi-layer spiral coil 11 structure within a single shell 2, each coil 11 is theoretically equivalent to a heat exchanger, realizing the multi-stage heat exchange function that originally required multiple heat exchangers connected in series. The overall structure is compact and the flow channel is clear, improving the heat exchange efficiency and operational stability of the system. Since the coil assembly 1 continuously coils along the axial direction of the shell 2 to form a multi-layer spiral structure, the shell-side medium can form a spiral tangential disturbance during flow, thereby enhancing fluid turbulence and thermal boundary layer renewal, significantly improving the heat transfer coefficient, and effectively reducing dead zones and flow deviation phenomena in the shell side. Compared with traditional multi-device series systems, this utility model reduces the number of external piping and headers through single-unit design, reduces the risk of leakage, and simplifies equipment installation and commissioning.

[0025] As a preferred embodiment of the above, the coil assembly 1 includes multiple coils 11 arranged coaxially along the axis of the shell 2 in several layers 12. The layers 12 divide the interior of the shell 2 into multiple annular sections 121 and a central circular section 122. Specifically, this can be achieved by sequentially nesting spiral structures of different diameters, forming multi-stage independent heat exchange units through axial stacking. (Refer to...) Figure 2 , 3 The diagram shows that there are three coils 11, which divide the interior of the shell 2 into three annular sections 121 and a central circular space. Other numbers of coils 11 are also possible, all within the scope of protection of this application. Specifically, by forming a multi-layered annular flow channel arranged coaxially in the shell 2, the heat exchange area can be expanded, and the shell-side fluid can be radially distributed in an orderly manner, thereby achieving higher heat exchange efficiency. The central circular section 122 provides an axial mainstream channel for the fluid, while the outer multi-layered annular sections 121 form a stable circulating heat exchange path, allowing the shell-side fluid to pass through each layer of coils 11 in sequence during the flow process, gradually completing the heat transfer and achieving the purpose of staged heat exchange.

[0026] Continue to refer to Figure 3 The first specific implementation method for arranging the layers is as follows: the layers are arranged at equal radial intervals, that is, the radial distance between adjacent layers 12 is kept consistent, which enables the shell 2 to form a regular multi-layer annular flow channel structure. The radial distance between adjacent coil layers is a fixed value. Standardization reduces manufacturing costs and time.

[0027] like Figure 4 As shown, the second specific implementation of the arrangement between the layers is as follows: the radial spacing between the layers gradually decreases from the inside to the outside. Specifically, in the above scheme of equal-spacing coil 11 arrangement, the shell-side fluid, due to its tendency to seek advantages and avoid disadvantages, will preferentially pass through the outer flow channel with a larger flow cross-sectional area and lower flow resistance, resulting in a severely uneven fluid distribution, with excessive flow in the outer layer and insufficient flow in the inner layer. In this embodiment, by appropriately increasing the inner layer spacing and decreasing the outer layer spacing, the flow cross-sectional area of ​​the shell-side flow channel between each layer tends to be consistent in the radial direction, thereby improving the uniformity of the shell-side fluid distribution between each layer and avoiding the problem of flow grabbing in the outer layer and insufficient flow in the inner layer.

[0028] like Figure 5As shown, the third specific implementation of the arrangement between the layers is as follows: the pitch of the coil 11 closer to the axis of the shell 2 is smaller than the pitch of the coil 11 farther from the axis of the shell 2. That is, the inner coil 11 is more compact, and the outer coil 11 is relatively loose. In the inner region, due to the shorter fluid flow path and narrower flow channel, the density of the coil 11 and the heat transfer area can be increased by reducing the pitch, so that the central region can obtain a stronger heat exchange capacity. In contrast, the outer region has a larger space, and appropriately increasing the pitch can reduce the outer flow resistance, promote the uniform distribution of fluid and smooth discharge from the shell side, thereby avoiding excessively low local flow velocity. The resulting heat transfer efficiency degradation problem can be addressed by this spiral structure with increasing pitch, which creates a gradient heat transfer intensity distribution from the inside out. This makes the overall temperature field within the shell more uniform, reducing local overheating and stress accumulation caused by heat concentration. At the same time, the layered pitch difference can also improve the spiral motion characteristics of the fluid, making the flow path naturally radially expanded, which helps to enhance turbulence and mixing. This not only improves the heat transfer uniformity and thermal efficiency of the coil 11 heat exchanger, but also effectively reduces flow resistance and thermal stress risks, achieving comprehensive optimization of heat transfer performance and structural reliability.

[0029] like Figure 6 As shown, a specific implementation method for the arrangement between adjacent layers is as follows: the coils 11 of adjacent layers 12 are arranged with the same spiral direction, that is, the multiple coils 11 are all arranged in the same spiral direction, such as all clockwise or all counterclockwise. When arranged in this way, the shell-side medium basically moves continuously along the same swirling direction when transitioning between each layer 12, and there is no obvious reversal of the flow direction between layers. The secondary flow and eddy current interference are relatively small, thus forming a relatively stable and continuous shell-side flow channel in the axial direction. This co-directional spiral arrangement is beneficial to reducing shell-side flow resistance and pressure loss along the friction. Under the premise of ensuring a certain heat exchange effect, it is suitable for high-flow-rate operating conditions that are more sensitive to pressure drop and operating energy consumption and require stable flow.

[0030] like Figure 7 As shown, another specific implementation method for the arrangement between adjacent layers is as follows: the coils 11 of adjacent layers 12 are arranged in opposite spiral directions. For example, one layer of coil 11 is wound in a clockwise direction, while the adjacent layer is wound in a counterclockwise direction, so that the flow direction of the shell-side medium between adjacent layers is opposite. This forms a swirling countercurrent and staggered flow in the boundary area between layers, significantly enhancing local shear and fluid disturbance. This can improve the turbulence intensity and mixing effect in the shell side, and promote the continuous breaking and renewal of the temperature boundary layer and velocity boundary layer, thereby significantly improving the local and overall heat transfer coefficient. Compared with the above-mentioned co-directional spiral arrangement, the reverse spiral arrangement is more advantageous in enhancing shell-side heat transfer and improving the uniformity of temperature field and flow distribution. However, it will introduce a certain additional flow resistance, which will slightly increase the shell-side pressure loss. It is suitable for working conditions that pursue higher heat transfer performance under the condition that a moderate increase in pressure drop is allowed.

[0031] Depending on the emphasis on pressure drop control and heat transfer enhancement under different operating conditions, the spiral direction of the corresponding coil 11 in adjacent layers 12 can be selected: when the system has strict requirements on flow resistance and energy consumption, a co-directional spiral arrangement is preferred to obtain a lower shell-side pressure drop and a more stable flow state; when more emphasis is placed on improving heat transfer capacity and the uniformity of shell-side flow and temperature distribution, a reverse spiral arrangement is preferred. By enhancing turbulence and mixing, the heat transfer performance can be significantly improved within an acceptable range of pressure drop increase, thereby achieving a reasonable balance between flow resistance and enhanced heat transfer.

[0032] As a preferred embodiment of the above, the cross-sectional shape of the coil 11 is circular or elliptical, at least one of them, to improve boundary layer flow and enhance heat transfer performance. Specifically, the choice of the cross-sectional shape of the coil 11 directly affects the flow state of the second medium 02 in the shell-side flow channel. When a circular cross-section is used, the fluid is uniformly distributed along the circumference of the tube wall, the boundary layer thickness increases slowly, and the flow separation phenomenon is suppressed. When an elliptical cross-section is used, the fluid forms an accelerated flow region in the long axis direction and generates local vortices in the short axis direction. Both cross-sectional shapes can enhance the convective heat transfer between the tube wall and the fluid by changing the velocity gradient distribution.

[0033] 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 coil heat exchanger, characterized in that, include: Housing and coil assembly disposed within the housing; The shell has a shell-side inlet and a shell-side outlet at both ends, and the shell has a tube-side inlet and a tube-side outlet on its sidewall. The coil assembly includes at least one continuously wound coil, each coil forming a multi-layered spiral structure along the axial direction of the housing. Each of the coils is connected at both ends to the tube inlet and the tube outlet, respectively, for the flow of the first medium; A shell-side flow channel for the flow of a second medium is formed between the coil assembly and the inner wall of the housing, so that the first medium flowing through the coil and the second medium flowing through the shell-side flow channel exchange heat through the coil wall.

2. The coil heat exchanger according to claim 1, characterized in that, The coil assembly includes multiple coils arranged coaxially along the axis of the housing in several layers, which divide the interior of the housing into multiple annular sections and a central circular section.

3. The coil heat exchanger according to claim 2, characterized in that, Each of the aforementioned levels is arranged at equal radial intervals.

4. The coil heat exchanger according to claim 2, characterized in that, The radial spacing between each of the aforementioned levels gradually decreases from the inside out.

5. The coil heat exchanger according to claim 3 or 4, characterized in that, The pitch of the coil closer to the housing axis is smaller than the pitch of the coil farther from the housing axis.

6. The coil heat exchanger according to claim 2, characterized in that, The spiral directions of the coils in adjacent layers are the same.

7. The coil heat exchanger according to claim 2, characterized in that, The spiral directions of the coils in adjacent layers are opposite.

8. The coil heat exchanger according to claim 1, characterized in that, The cross-sectional shape of the coil is circular or elliptical, or at least one of these.

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