Annular shell-and-tube heat exchanger with fins distributed in rhombus in flow channel

Abstract

The invention belongs to the technical field of design of annular shell-and-tube heat exchangers, and particularly relates to an annular shell-and-tube heat exchanger with fins distributed in a rhombus shape in a flow channel, fin-shaped bionic fins are designed to be distributed in the annular flow channel in a staggered mode in a rhombus shape, and when fluid flows, the fluid will firstly pass through the first fin-shaped bionic fin arranged in the center to be disturbed and then pass through the second fin-shaped bionic fin arranged in the center to be disturbed; according to the annular shell-and-tube heat exchanger, fluid flows through the first fin-shaped bionic fins, then diffusely flows through the two second fin-shaped bionic fins, and contractively flows through the two third fin-shaped bionic fins, so that the fluid can further fully flow, the short circuit phenomenon is reduced, the streaming is enhanced, and the effective heat exchange area is increased; the heat exchange effect can be improved by more than 15%, and the heat exchange capacity is greatly improved.

Description

Technical Field

[0001] The present application belongs to the technical field of annular shell and tube heat exchanger design, and specifically relates to an annular shell and tube heat exchanger with rhombus-shaped fins distributed in a flow channel. Background Art

[0002] Shell and tube heat exchanger is one type of partition heat exchanger. It has simple structure, convenient manufacturing, installation, cleaning and maintenance, low price, high reliability and wide adaptability. It is widely used in chemical, petroleum, refrigeration, nuclear energy and power industries, especially suitable for cooling and condensing high-pressure fluids.

[0003] Intensifying heat transfer by adding fins has been widely used in heat exchangers. Adding fins to the flow channel of annular shell and tube heat exchangers helps to increase the heat transfer area and enhance the disturbance of the flow field. However, directly adding fins to the flow channel of annular shell and tube heat exchangers often results in a situation where the pressure drop increases sharply and the heat dissipation improvement effect is minimal, and the enhanced heat transfer effect is not good.

[0004] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0005] The purpose of the present application is to provide an annular shell and tube heat exchanger with rhombus-shaped fins distributed in the flow channel, so as to overcome or alleviate at least one aspect of the known technical defects.

[0006] The technical solution of this application is:

[0007] An annular shell and tube heat exchanger with rhombus-shaped fins distributed in a flow channel, comprising a shell and an internal flow channel;

[0008] The outer shell comprises an inner wall and an outer wall;

[0009] An internal flow channel is formed between the inner wall and the outer wall, and a fluid inlet and a fluid outlet are provided on the outer wall;

[0010] A plurality of split rings are arranged in the internal flow channel to divide the internal flow channel into a plurality of annular flow channels in the axial direction;

[0011] The annular flow channels at both ends are connected to the fluid inlet and the fluid outlet;

[0012] A connecting port is provided on the middle split ring, and two adjacent annular flow channels are connected through the connecting port;

[0013] A plurality of fish-fin-shaped bionic fin groups are arranged in the annular flow channel along the circumferential direction;

[0014] The fish fin-shaped bionic fin group includes a first fish fin-shaped bionic fin, two second fish fin-shaped bionic fins, and two third fish fin-shaped bionic fins arranged in sequence, wherein:

[0015] A first fish-fin-shaped bionic fin is arranged on the center line of the annular flow channel and is parallel to the annular flow channel;

[0016] The two second fish-fin-shaped bionic fins are symmetrically distributed along the center line of the annular flow channel and are inclined to the center line of the annular flow channel. The farther the second fish-fin-shaped bionic fins are from the first fish-fin-shaped bionic fin, the farther the distance between the two second fish-fin-shaped bionic fins is.

[0017] The two third fish fin-like bionic fins are symmetrically distributed along the center line of the annular flow channel and inclined to the center line of the annular flow channel. The farther away from the second fish fin-like bionic fins, the closer the two third fish fin-like bionic fins are, forming a diamond structure between the two second fish fin-like bionic fins.

[0018] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with rhombus-shaped fins distributed in the flow channel, the fish-fin-shaped bionic fin group is arranged on the inner wall and extends from the inner wall to the outer wall;

[0019] The first fish fin-shaped bionic fin, the second fish fin-shaped bionic fin, and the third fish fin-shaped bionic fin have the same height;

[0020] The thickness of the first fish fin-shaped bionic fin is 2.5-3.5 times the thickness of the second fish fin-shaped bionic fin and the third fish fin-shaped bionic fin.

[0021] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with diamond-shaped fins distributed in the flow channel, in the fish-fin-shaped bionic fin group, the thickness of the first fish-fin-shaped bionic fin is 3 times the thickness of the second fish-fin-shaped bionic fin and the third fish-fin-shaped bionic fin.

[0022] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with rhombus-shaped fin distribution in the flow channel, in the fish-fin-shaped bionic fin group, the first fish-fin-shaped bionic fin, the second fish-fin-shaped bionic fin and the third fish-fin-shaped bionic fin are arranged alternately at intervals of 2.5° to 3.5° in the circumferential direction;

[0023] The thickness of the first fish-fin-shaped bionic fin is 1.5 to 1.8 mm;

[0024] The thickness of the two second fish fin-shaped bionic fins and the third fish fin-shaped bionic fins is 0.7 to 0.9 mm.

[0025] The maximum interval between the two second fish fin-shaped bionic fins and the third fish fin-shaped bionic fins is 5 mm to 6 mm, and the angle is 25 to 35 degrees.

[0026] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with rhombus-shaped fins distributed in the flow channel, the fish-fin-shaped bionic fin group includes:

[0027] sinA = ab*ln(H / S);

[0028] B = A*cosθ;

[0029] in,

[0030] A is the circumferential span angle of a fin;

[0031] a and b are calculation parameters;

[0032] H is the height of the top protrusions of the first fish fin-shaped bionic fin, the second fish fin-shaped bionic fin, and the third fish fin-shaped bionic fin;

[0033] S is the effective distance between the two second fish fin-shaped bionic fins and between the two third fish fin-shaped bionic fins;

[0034] B is the circumferential span angle of the second fish fin-shaped bionic fin and the third fish fin-shaped bionic fin;

[0035] θ is the angle between the two second fish fin-shaped bionic fins and the angle between the two third fish fin-shaped bionic fins.

[0036] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with rhombus-shaped fins distributed in the flow channel, the fish-fin-shaped bionic fin group includes:

[0037] S = (S1-S2) / 2;

[0038] in,

[0039] S1 is the maximum distance between the two second fish fin-shaped bionic fins and between the two third fish fin-shaped bionic fins;

[0040] S2 is the minimum distance between the two second fish fin-shaped bionic fins and between the two third fish fin-shaped bionic fins.

[0041] According to at least one embodiment of the present application, in the aforementioned annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel, a=0.1884;

[0042] b=0.138.

[0043] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with diamond-shaped fins distributed in the flow channel, H is 3.2 mm to 3.4 mm.

[0044] According to at least one embodiment of the present application, in the above-mentioned annular shell and tube heat exchanger with diamond-shaped fins distributed in the flow channel, S is 5 mm to 6 mm.

[0045] According to at least one embodiment of the present application, in the aforementioned annular shell and tube heat exchanger with diamond-shaped fins in the flow channel, the connecting openings on adjacent split rings are distributed at 180°.

[0046] This application has at least the following beneficial technical effects:

[0047] Provided is an annular shell and tube heat exchanger with rhombus-shaped fins in a flow channel, wherein fish-fin-shaped bionic fins are designed to be arranged alternately in a rhombus shape in the annular flow channel, and when the fluid flows, it will first pass through a first fish-fin-shaped bionic fin turbulence arranged in the center, and then pass through two second fish-fin-shaped bionic fins for diffusion flow, and then pass through two third fish-fin-shaped bionic fins for contraction flow, thereby enabling the fluid to flow further fully, reducing short-circuiting, enhancing bypass flow, and increasing the effective heat exchange area, and relative to an annular shell and tube heat exchanger with non-rhombus-shaped fin distribution, the heat exchange effect can be improved by more than 15%, and the heat exchange capacity is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of an annular shell and tube heat exchanger with rhombus-shaped fins distributed in the flow channel provided in an embodiment of the present application;

[0049] Figure 2 It is a display diagram of the internal flow channel design provided in the embodiment of the present application;

[0050] Figure 3 is a schematic diagram of a fish fin-shaped bionic fin provided in an internal flow channel provided in an embodiment of the present application;

[0051] in:

[0052] 1- shell; 2- internal flow channel;

[0053] 1-1-inner wall; 1-2-outer wall;

[0054] 2-1-dividing ring; 2-2-annular flow channel; 2-3-fluid inlet; 2-4-fluid outlet; 2-5-left flow channel; 2-6-right flow channel; 2-7-connecting port; 2-8-fish fin-shaped bionic fin group;

[0055] 2-8-1-the first fish fin-shaped bionic fin; 2-8-2-the second fish fin-shaped bionic fin; 2-8-3-the third fish fin-shaped bionic fin.

[0056] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0057] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0058] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0059] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0060] An annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel, such as Figure 1 As shown, it includes a shell 1 and an internal flow channel 2.

[0061] The housing 1 includes an inner wall 1 - 1 and an outer wall 1 - 2 .

[0062] The inner wall 1-1 is a circular structure, and the outer wall 1-2 is a polygonal structure, preferably a polygon with more than eight sides, and optionally, the center of the circle is the center of the polygon; or the outer wall 1-2 is a circle, and the inner wall 1-1 circle and the outer wall 1-2 circle have the same center.

[0063] An internal flow channel 2 is formed between the inner wall 1 - 1 and the outer wall 1 - 2 , and a fluid inlet 2 - 3 and a fluid outlet 2 - 4 communicating with the internal flow channel 2 are provided on the outer wall 1 - 2 .

[0064] like Figure 2 As shown, a plurality of split rings 2-1 are arranged in the internal flow channel 2, thereby dividing the internal flow channel 2 into a plurality of annular flow channels 2-2 in the axial direction.

[0065] The annular flow channels 2-2 located at both ends are connected to the fluid inlet 2-3 and the fluid outlet 2-4.

[0066] A connecting port 2-7 is provided on the middle split ring 2-1, and two adjacent annular flow channels 2-2 form a series structure through the connecting port 2-7. Adjacent connecting ports 2-7 are distributed at 180 degrees.

[0067] From the perspective of fluid flow, the annular flow channel 2-2 can be divided into a U-shaped structure in which a left flow channel 2-5 and a right flow channel 2-6 are connected in parallel.

[0068] A plurality of fish-fin-shaped bionic fin groups 2-8 are arranged in the annular flow channel 2-2 along the fluid flow direction.

[0069] The fish fin-shaped bionic fin group 2-8 includes a first fish fin-shaped bionic fin 2-8-1, two second fish fin-shaped bionic fins 2-8-2, and two third fish fin-shaped bionic fins 2-8-3 arranged in sequence, wherein a first fish fin-shaped bionic fin 2-8-1 is arranged on the center line of the annular flow channel 2-2 and is parallel to the annular flow channel 2-2; the two second fish fin-shaped bionic fins 2-8-2 are symmetrically distributed along the center line of the annular flow channel 2-2 and are inclined to the center line of the annular flow channel 2-2 The farther from the first fish fin-shaped bionic fin 2-8-1, the farther the distance between the two second fish fin-shaped bionic fins 2-8-2; the two third fish fin-shaped bionic fins 2-8-3 are symmetrically distributed along the center line of the annular flow channel 2-2 and inclined to the center line of the annular flow channel 2-2, the farther from the second fish fin-shaped bionic fin 2-8-2, the closer the distance between the two third fish fin-shaped bionic fins 2-8-3, forming a diamond structure with the two second fish fin-shaped bionic fins 2-8-2.

[0070] In the annular shell and tube heat exchanger with diamond-shaped fins in the flow channel disclosed in the above embodiment, the U-shaped parallel flow channel and the fish-fin-shaped bionic fin are integrated. Compared with the traditional spiral and S-shaped series flow channels, the U-shaped parallel flow channel can reduce the pressure drop and have better temperature uniformity performance. The fish-fin-shaped bionic fins are designed to be staggered in the annular flow channel 2-2, which can enhance the bypass flow, increase the effective heat exchange area, and improve the convective heat transfer coefficient.

[0071] In the annular shell and tube heat exchanger with diamond-shaped fins in the flow channel disclosed in the above-mentioned embodiment, the fish-fin-shaped bionic fins are designed to be arranged in a diamond shape in an alternating manner in the annular flow channel 2-2. When the fluid flows, it will first pass through the first fish-fin-shaped bionic fin 2-8-1 arranged in the center for turbulence, then pass through the two second fish-fin-shaped bionic fins 2-8-2 for diffusion flow, and then pass through the two third fish-fin-shaped bionic fins 2-8-3 for contraction flow. In this way, the fluid can flow more fully, reduce short-circuiting, enhance bypass flow, and increase the effective heat exchange area. Compared with the annular shell and tube heat exchanger with non-diamond-shaped fins distribution, the heat exchange effect can be improved by more than 15%, and the heat exchange capacity is greatly improved.

[0072] In the fish fin-shaped bionic fin group 2-8, the second fish fin-shaped bionic fin 2-8-2 and the third fish fin-shaped bionic fin 2-8-3 are distributed in a diamond shape, which can make the fluid flowing in the center of the flow channel diffuse and contract, and the fluid flowing at the edge contract and diffuse, and then mix together and impact each other, further improving the heat exchange effect.

[0073] The first fish fin-shaped bionic fin 2-8-1, the second fish fin-shaped bionic fin 2-8-2 and the third fish fin-shaped bionic fin 2-8-3 in the fish fin-shaped bionic fin group 2-8 have the same structure, including a first curved wall and a second curved wall connected to each other, wherein the length of the first curved wall is greater than the length of the second curved wall, and the bending radius of the first curved wall is less than the bending radius of the second curved wall. The first curved wall is located upstream of the fluid flow, and the second curved wall is located downstream of the fluid flow. The bending radius and length of the second curved wall arranged downstream are smaller than the first curved wall, and the fluid will first contact the first curved wall when flowing in the annular flow channel 2-2. Because the slope of the first curved wall is relatively gentle and the contact surface with the fluid is large, the fluid can fully contact the bionic fin for heat exchange under relatively small resistance. The second curved wall increases the heat exchange area, and the heat exchange area of ​​the second curved wall of the same length increases, because the flow resistance at the downstream is basically not increased, so by setting the size of the first curved wall and the second curved wall and the change of the bending radius, the heat exchange area can be increased while maintaining the same resistance, the heat exchange effect is improved, and the distribution area of ​​the fin is saved, saving costs.

[0074] A fish-fin-shaped bionic fin group 2-8 is arranged in the annular flow channel 2-2. When viewed along the axial direction, the fish-scale-shaped bionic fin protrusions in adjacent annular flow channels 2-2 are in opposite directions. Through this design, the fluid can continue to be subjected to the same turbulence effect when flowing in the annular flow channel 2-2, thereby reducing the increment of flow resistance.

[0075] The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel disclosed in the above embodiment is arranged in the up-down direction, and a preferred embodiment is as follows: Figure 2 As shown, the fluid inlet 2-3 and the fluid outlet 2-4 are arranged at the top of the housing 1. Such an arrangement allows the fluid to flow in the flow channel by gravity and allows the fluid to fully contact the wall surface.

[0076] The connecting port 2-7 on the split ring 2-1 is arranged at the upper part or the lower part of the internal flow channel 2. By being arranged at the upper part or the lower part, the fluid can flow from the top end to the bottom end, or from the bottom end to the top end, so that the fluid can flow in the flow channel by gravity and make the fluid fully contact with the wall surface; or flow by anti-gravity, so that the fluid can fully exchange heat in the flow.

[0077] The fish fin-shaped bionic fin group 2-8 is arranged on the inner wall 1-1, and extends from the inner wall 1-1 to the outer wall 1-2. The height of the first fish fin-shaped bionic fin 2-8-1 is the same as that of the second fish fin-shaped bionic fin 2-8-2 and the third fish fin-shaped bionic fin 2-8-3. The thickness of the first fish fin-shaped bionic fin 2-8-1 is 2.5-3.5 times, preferably 3 times, of the thickness of the second fish fin-shaped bionic fin 2-8-2 and the third fish fin-shaped bionic fin 2-8-3. During the heat dissipation process, the thicker first fish fin-shaped bionic fin 2-8-1 can fully conduct heat, and the thinner second fish fin-shaped bionic fin 2-8-2 and the third fish fin-shaped bionic fin 2-8-3 can reserve sufficient channels for the fluid while ensuring heat conduction, so as not to cause excessive resistance. The thickness of the first fish-fin-shaped bionic fin 2-8-1 and the thickness ratio of the second fish-fin-shaped bionic fin 2-8-2 and the third fish-fin-shaped bionic fin 2-8-3 are also the best relationship obtained through experiments and numerical simulations, achieving the best heat exchange effect while ensuring resistance.

[0078] Optionally, when the fluid in the annular flow channel 2-2 flows from the upper part to the lower part, the angle between the second fish fin-shaped bionic fin 2-8-2 and the angle between the third fish fin-shaped bionic fin 2-8-3 and the axis of the inner wall 1-1 is increasingly larger, that is, the angle between the second fish fin-shaped bionic fin 2-8-2 and the center line of the flow channel is increasingly larger, and the angle between the third fish fin-shaped bionic fin 2-8-3 and the center line of the flow channel is increasingly larger. Because with the acceleration of gravity, the flow rate will increase. By setting it in this way, the degree of disturbance in the downstream process becomes increasingly larger, and the flow rate can also maintain a relatively uniform speed, and the heat absorption process is also increased, which can further improve the heat exchange effect.

[0079] Optionally, when the fluid in the annular flow channel 2-2 flows from the upper part to the lower part, the angle between the second fish fin-shaped bionic fin 2-8-2 and the angle between the third fish fin-shaped bionic fin 2-8-3 and the axis of the inner wall 1-1 is increasingly increasing, that is, the angle between the second fish fin-shaped bionic fin 2-8-2 and the center line of the flow channel is increasingly increasing, and the angle between the third fish fin-shaped bionic fin 2-8-3 and the center line of the flow channel is increasingly increasing. Because with the acceleration of gravity, the flow rate will increase. By setting it in this way, the heat exchange effect can be further improved. The above is the effect obtained through a large number of experiments and numerical simulations.

[0080] Optionally, the distribution density of the fins in the annular flow channel 2-2 where the fluid flows from the upper part to the lower part is greater than the distribution density of the annular flow channel 2-2 where the fluid flows from the lower part to the upper part. That is, when the inlet of the annular flow channel 2-2 is located at the top of the upper part, the inlet of the adjacent annular flow channel 2-2 is located at the bottom of the lower part, and the distribution density of the fins where the inlet of the annular flow channel 2-2 is located at the upper part is greater than that where the inlet is located at the lower part. Because when the upper part flows downward, the flow resistance is small due to the action of gravity, and when it flows from the bottom to the top, the flow resistance is large, so by setting the fin density, uniform flow is achieved through the change of flow resistance, balanced pressure, and thus heat exchange is promoted.

[0081] The annular shell-and-tube heat exchanger with rhombus-shaped fins in the flow channel disclosed in the above embodiment can be used as a radiator, wherein the inner ring formed by the inner wall 1-1 is a heat source, and the heat source dissipates heat outward through the internal flow channel 2. The cold fluid in the internal flow channel 2 is air or water. The outer wall 1-2 can be provided with an observation hole, such as Figure 1 As shown, it is used to observe the internal fluid flow conditions.

[0082] Existing motor cooling systems are mainly divided into air cooling and water cooling systems. Air cooling systems do not require too complicated auxiliary facilities, but cannot meet the heat dissipation requirements of high power density motors. Liquid cooling systems mostly rely on liquids with physical parameters superior to gases, such as water, oil, etc., and can produce very good cooling effects with the help of auxiliary settings. Traditional liquid cooling methods usually set evaporators or flow channels outside the casing, and the coolant is far away from the heat source, which has poor heat dissipation effects for the rotor and stator. Another way is to insert cooling pipes on the stator, such as inserting cooling pipes into the stator slots and stator yokes. Although this cooling method shortens the distance to the heat source, the cooling pipes in the slots take up a lot of space and are not suitable for motors with multi-slot stators. The structure is complex and the assembly is difficult. Another way is for the coolant to directly contact the heat source inside the motor. Although this cooling method has a better effect, it has high requirements for sealing, many cooling device components, complex cooling structure, high cost, and the cooling medium can only be oil.

[0083] The annular shell and tube heat exchanger with diamond-shaped fins in the flow channel disclosed in the above embodiment is applied to the heat dissipation of the motor. The motor is set in the inner ring formed by the inner wall 1-1. The inner wall 1-1 and the stator are directly bonded by heat-conducting material, and the heat emitted by the stator can be conducted by the inner wall 1-1 to the wall surface of the internal flow channel 2 and the fish fin-shaped bionic fins. At the same time, the fluid flows in from the inlet at the top of the shell 1, and then splits under the action of gravity, flows downward through the right flow channel 2-6 and the left flow channel 2-5 respectively, and then intersects at the bottom, and enters the next annular flow channel 2-2 through the bottom connecting port 2-7 channel. Under the action of pressure, the fluid splits upward again and intersects at the top, and enters the next annular flow channel 2-2 through the top connecting port 2-7 channel again. The flow is repeated in this way, and finally flows out at the outlet of the shell 1. During the flow process, the working medium performs convection heat exchange with the bottom of the flow channel and the fish fin-shaped bionic fins distributed in the flow channel, and takes away the heat of the heat-generating components such as the stator bonded to the inner wall 1-1.

[0084] Optionally, the width of each annular flow channel 2-2 is 12mm to 13mm, and the height is 5mm to 6mm, and the ratio of the two is required to be between 2 and 3, so as to ensure that the fluid has sufficient contact area with the flow channel near the inner wall 1-1. The thickness of the split ring 2-1 is 3.5mm to 4.5mm, and each split ring 2-1 is provided with a connecting port 2-7, and the circumferential span of each connecting port 2-7 is 29° to 31°, so that the flow velocity of the fluid in the parallel flow channels changes little when it intersects and re-divides, so as to meet the optimal requirements of flow resistance and heat exchange.

[0085] like Figure 3 As shown, the fish fin-shaped bionic fins distributed in each annular flow channel 2-2 are arranged in a staggered manner with an interval of 2.5° to 3.5° along the circumferential direction. The first fish fin-shaped bionic fin 2-8-1 is located in the center of the flow channel, and its thickness is 1.5 to 1.8 mm. The second fish fin-shaped bionic fin 2-8-2 and the third fish fin-shaped bionic fin 2-8-3 are symmetrically distributed in a rhombus shape on both sides of the middle plane of the flow channel. In the axial direction, the two second fish fin-shaped bionic fins 2 -8-2, the maximum interval between the two third fish-fin-shaped bionic fins 2-8-3 is 5mm~6mm, the angle is 25~35°, the thickness is 0.7~0.9mm, the circumferential span of the first fish-fin-shaped bionic fin 2-8-1 is 14.5°~15.5°, and the height of the top protrusion of each fin is 3.2mm~3.4mm; the first curved wall curvature radius of each fin is 14mm~17mm, and the corresponding arc length is 9mm~11mm, and the second curved wall curvature radius is 26mm~29mm, and the corresponding arc length is 4mm~6mm. The above-mentioned optimal dimensions are the preferred dimensions obtained through a large number of numerical simulations and experimental studies, which can meet the flow resistance (600-700pa) and achieve the best heat exchange requirements.

[0086] It is found in experiments and numerical simulations that the protrusion height H at the top of the fin, the fin pitch, and the circumferential span of the fins cannot be too large or too small, otherwise the heat transfer effect will be poor or the resistance will be too high. Based on a large number of numerical simulations and experiments, the following optimizations are carried out to ensure the best heat transfer effect under a small increase in flow resistance:

[0087] As Figure 3 , assuming that the protrusion height at the top of the fin is H, the maximum axial pitch between the second fish-fin-shaped bionic fins 2-8-2 and between the third fish-fin-shaped bionic fins 2-8-3 is S1, the minimum axial pitch is S2, and S=(S1 - S2) / 2 / 2; the circumferential span angle of the first fish-fin-shaped bionic fin 2-8-1 is A, and the following requirements are met: sinA = a - b*ln(H / S), where a and b are parameters, satisfying 0.1880 < a < 0.1890, 0.135 < b < 01.40, A is 14.5° to 15.5°, H is 3.2 mm to 3.4 mm, and S is 5 mm to 6 mm. The included angle between the second fish-fin-shaped bionic fins 2-8-2 and between the third fish-fin-shaped bionic fins 2-8-3 is θ, and the circumferential span of the second fish-fin-shaped bionic fins 2-8-2 and the third fish-fin-shaped bionic fins 2-8-3 is B = A*cosθ.

[0088] Optionally, the included angle between the second fish-fin-shaped bionic fins 2-8-2 and between the third fish-fin-shaped bionic fins 2-8-3 is 25 to 35°.

[0089] Optionally, a = 0.1884 and b = 0.138.

[0090] As Figure 2 As shown, the fluid working medium flows in from the fluid inlet 2-3 at the top of the outer shell 1, and then is divided under the action of gravity, flowing downward through the left flow channel 2-5 and the right flow channel 2-6 respectively and then converging at the bottom, entering the next annular flow channel 2-2 through the bottom communication port 2-7 channel. Under the action of pressure, the fluid is divided upward again and converges at the top, and then enters the next annular flow channel 2-2 through the top communication port 2-7 channel again, repeating the flow in this way, and finally flowing out from the fluid outlet 2-4 at the top of the outer shell 1. During the flow process, the working medium exchanges convective heat with the bottom of the flow channel and the fish-fin-shaped bionic fins distributed in the flow channel, taking away the heat of the stator and other heat-generating components in contact with the inner wall 1-1.

[0091] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. An annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel, characterized in that: It comprises a shell (1) and an internal flow channel (2); The outer shell (1) comprises an inner wall (1-1) and an outer wall (1-2); An internal flow channel (2) is formed between the inner wall (1-1) and the outer wall (1-2), and the outer wall (1-2) is provided with a fluid inlet (2-3) and a fluid outlet (2-4); A plurality of split rings (2-1) are arranged in the internal flow channel (2) to divide the internal flow channel (2) into a plurality of annular flow channels (2-2) in the axial direction; The annular flow channels (2-2) at both ends are connected to the fluid inlet (2-3) and the fluid outlet (2-4); A communication port (2-7) is provided on the middle split ring (2-1), and two adjacent annular flow channels (2-2) are connected via the communication port (2-7); A plurality of fish-fin-shaped bionic fin groups (2-8) are arranged in the annular flow channel (2-2) along the circumferential direction; The fish fin-shaped bionic fin group (2-8) comprises a first fish fin-shaped bionic fin (2-8-1), two second fish fin-shaped bionic fins (2-8-2), and two third fish fin-shaped bionic fins (2-8-3) which are arranged in sequence, wherein: A first fish-fin-shaped bionic fin (2-8-1) is arranged on the center line of the annular flow channel (2-2) and is parallel to the annular flow channel (2-2); The two second fish-fin-shaped bionic fins (2-8-2) are symmetrically distributed along the center line of the annular flow channel (2-2) and are inclined to the center line of the annular flow channel (2-2). The farther the second fish-fin-shaped bionic fins (2-8-2) are from the first fish-fin-shaped bionic fin (2-8-1), the farther the distance between the two second fish-fin-shaped bionic fins (2-8-2) is. The two third fish-fin-shaped bionic fins (2-8-3) are symmetrically distributed along the center line of the annular flow channel (2-2) and are inclined to the center line of the annular flow channel (2-2); the farther away from the second fish-fin-shaped bionic fins (2-8-2), the closer the distance between the two third fish-fin-shaped bionic fins (2-8-3) is, forming a diamond structure with the two second fish-fin-shaped bionic fins (2-8-2).

2. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 1, characterized in that: The fish-fin-shaped bionic fin group (2-8) is arranged on the inner wall (1-1) and extends from the inner wall (1-1) toward the outer wall (1-2); The first fish fin-shaped bionic fin (2-8-1), the second fish fin-shaped bionic fin (2-8-2), and the third fish fin-shaped bionic fin (2-8-3) have the same height; The thickness of the first fish-fin-shaped bionic fin (2-8-1) is 2.5-3.5 times the thickness of the second fish-fin-shaped bionic fin (2-8-2) and the third fish-fin-shaped bionic fin (2-8-3).

3. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 2, characterized in that: In the fish fin-shaped bionic fin group (2-8), the thickness of the first fish fin-shaped bionic fin (2-8-1) is three times the thickness of the second fish fin-shaped bionic fin (2-8-2) and the third fish fin-shaped bionic fin (2-8-3).

4. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 3, characterized in that: In the fish fin-shaped bionic fin group (2-8), the first fish fin-shaped bionic fin (2-8-1), the second fish fin-shaped bionic fin (2-8-2) and the third fish fin-shaped bionic fin (2-8-3) are arranged alternately at intervals of 2.5° to 3.5° in the circumferential direction; The first fish-fin-shaped bionic fin (2-8-1) has a thickness of 1.5 to 1.8 mm; The thickness of the two second fish fin-shaped bionic fins (2-8-2) and the third fish fin-shaped bionic fin (2-8-3) is 0.7 to 0.9 mm. The maximum interval between the two second fish-fin-shaped bionic fins (2-8-2) and the third fish-fin-shaped bionic fin (2-8-3) is 5 mm to 6 mm, and the included angle is 25 to 35 degrees.

5. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 4, characterized in that: The fish fin-shaped bionic fin set (2-8) includes: sinA = ab*ln(H / S); B = A*cosθ; in, A is the circumferential span angle of a fin (2-8-1); a and b are calculation parameters; H is the height of the top protrusions of the first fish fin-shaped bionic fin (2-8-1), the second fish fin-shaped bionic fin (2-8-2), and the third fish fin-shaped bionic fin (2-8-3); S is the effective distance between the two second fish fin-shaped bionic fins (2-8-2) and between the two third fish fin-shaped bionic fins (2-8-3); B is the circumferential span angle of the second fish fin-shaped bionic fin (2-8-2) and the third fish fin-shaped bionic fin (2-8-3); θ is the angle between the two second fish-fin-shaped bionic fins (2-8-2) and the angle between the two third fish-fin-shaped bionic fins (2-8-3).

6. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 5, characterized in that: The fish fin-shaped bionic fin set (2-8) includes: S = (S1 + S2) / 2; in, S1 is the maximum distance between the two second fish fin-shaped bionic fins (2-8-2) and between the two third fish fin-shaped bionic fins (2-8-3); S2 is the minimum distance between the two second fish-fin-shaped bionic fins (2-8-2) and between the two third fish-fin-shaped bionic fins (2-8-3).

7. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 6, characterized in that: a＝0.1884； b＝0.138。 8. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 7, characterized in that: H is 3.2mm~3.4mm.

9. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 8, characterized in that: S is 5mm~6mm.

10. The annular shell and tube heat exchanger with rhombus-shaped fins in the flow channel according to claim 9, characterized in that: The communication openings (2-7) on adjacent segmentation rings (2-1) are distributed at 180°.

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