Flow distribution structure and heat exchanger

Abstract

The invention relates to the technical field of heat exchanger design. The invention discloses a flow distribution structure and a heat exchanger, the flow distribution structure is arranged on a shell of the heat exchanger, the flow distribution structure comprises a shell, the shell is sleeved with the shell, and the shell and the shell are connected to form a containing cavity; the flow dividing holes are formed in the shell, the flow dividing holes communicate with the containing cavity and an inner cavity of the shell, and the multiple flow dividing holes are evenly distributed in the circumferential direction of the axis of the shell; the communication hole is formed in the shell, and the communication hole is communicated with the containing cavity and an external pipeline; and the fins are arranged on the outer shell and the shell body, and the fins are located in the containing cavity. The shell and the shell are connected to form the containing cavity, and the flow distribution uniformity of the flow dividing holes is enhanced through the arrangement of the flow dividing holes, the communicating holes and the fins, so that the uniformity of the flow of an inlet and an outlet of the heat exchanger in the circumferential direction is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchanger design, and in particular to a flow distribution structure and a heat exchanger. Background Art

[0002] Shell and tube heat exchangers have simple structures, good economic efficiency, wide flow cross-sections, are easy to clean, and can be used under high temperature and high pressure. They account for about 70% of industrial heat exchangers and are the most widely used type of heat exchanger. Therefore, improving the comprehensive performance of shell and tube heat exchangers is of great significance to improving energy utilization efficiency, saving energy and reducing emissions.

[0003] In common shell-and-tube heat exchangers, the fluid on the tube side passes through the tube sheets on both ends and goes straight in and out, while the fluid on the shell side enters and exits from the side. Usually, at the inlet and outlet of the shell side fluid, there is a sudden expansion and contraction structure when the inlet and outlet external pipes are connected to the heat exchanger shell. As a result, the high-speed fluid at the inlet will directly impact the tube bundle, causing strong flow-induced vibration and increasing fatigue damage. In addition, the inlet jet will cause a dead zone of flow, causing a relatively uneven flow field distribution at the shell inlet, resulting in uneven heating of the heat exchange tubes. This not only reduces the safety of the heat exchanger, but also is not conducive to heat transfer, hindering the process of compacting the heat exchanger.

[0004] Therefore, it is necessary to design a flow-balancing structure to prevent the high-speed fluid at the inlet from directly impacting the tube bundle, to promote uniform circumferential distribution of the fluid at the shell inlet and outlet, to reduce heat transfer dead zones and fluid-induced vibrations, and to maximize the use of the heat transfer surface of the shell inlet and outlet tube bundles. Summary of the invention

[0005] In view of this, the present invention provides a flow distribution structure and a heat exchanger.

[0006] Specifically, the following technical solutions are included:

[0007] In a first aspect, a flow distribution structure is provided, which is arranged on a shell of a heat exchanger, and the flow distribution structure comprises:

[0008] An outer shell, wherein the outer shell is sleeved on the shell, and the outer shell and the shell are connected to form a receiving chamber;

[0009] A flow diversion hole, wherein the flow diversion hole is arranged on the shell, the flow diversion hole communicates with the accommodating chamber and the inner cavity of the shell, and a plurality of the flow diversion holes are evenly arranged circumferentially around the axis of the shell;

[0010] A connecting hole, the connecting hole is arranged on the housing, and the connecting hole connects the accommodating chamber and the external pipeline;

[0011] The ribs are arranged on the outer shell and the housing, and the ribs are located in the accommodating chamber.

[0012] Preferably, the ratio of the sum of the diameters of the plurality of diverter holes to the circumferential length of the outer wall of the shell is within a first numerical range.

[0013] Preferably, the number of the diversion holes is greater than or equal to 8, and the number of the diversion holes is a positive multiple of the preset number of holes.

[0014] Preferably, the vertical distance between the plane where the axis of the diversion hole is located and the center of the connecting hole is within a second numerical range.

[0015] Preferably, the cross section of the rib is circular or polygonal;

[0016] The ribs extend along an axial extension direction of the housing.

[0017] Preferably, the ribs include a first rib and a second rib, the first rib is arranged on the shell, and the second rib is arranged on the shell;

[0018] The first rib and the second rib are respectively arranged on the perpendicular bisector of the line connecting the centers of two adjacent diversion holes;

[0019] The first ribs and the second ribs are alternately arranged along the circumferential direction of the shell.

[0020] Preferably, the length of the first rib extending radially along the shell is a first height;

[0021] The length of the second fin extending in the radial direction of the shell is a second height;

[0022] The ratio of the first height to the second height is within a third numerical range, and the sum of the first height and the second height is within a fourth numerical range.

[0023] Preferably, at least two first ribs are provided, and the at least two first ribs are symmetrically arranged with the plane where the connecting hole axis and the shell axis are located as a symmetry plane;

[0024] At least two second ribs are provided, and the at least two second ribs are symmetrically arranged with the plane where the connecting hole axis and the shell axis are located as a symmetry plane.

[0025] Preferably, the ratio of the diameter of the outer shell to the diameter of the shell is within a fifth numerical range.

[0026] In a second aspect, a heat exchanger is provided, on which a flow distribution structure as described in the first aspect is provided.

[0027] The beneficial effects of the technical solution provided by the present invention include at least:

[0028] The present invention forms a containing chamber by connecting the outer shell and the shell, and enhances the flow distribution uniformity of each diversion hole by arranging the diversion hole, the connecting hole and the fin, thereby enhancing the uniformity of the inlet and outlet flow of the heat exchanger along the circumferential direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is a schematic diagram of the heat exchanger structure according to one embodiment of the present invention;

[0031] Figure 2 A schematic diagram of a flow distribution structure according to an embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of the AA cross-sectional structure of a flow distribution structure according to an embodiment of the present invention;

[0033] Figure 4 The figure is a flow distribution comparison diagram of an embodiment of the present invention.

[0034] The reference numerals in the figures represent respectively:

[0035] 1-connecting hole; 2-diverter hole; 3-housing; 4-first rib; 5-second rib; 6-inlet flow distribution structure; 7-outlet flow distribution structure; 8-housing.

[0036] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Before further describing the embodiments of the present invention in detail, the directional nouns involved in the embodiments of the present invention, such as "upper part", "lower part", "side part", etc., are Figure 1The directions shown in the figure are for reference only and do not limit the protection scope of the present invention.

[0039] To make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0040] In view of the above problems, the present invention provides a flow distribution structure, including a connecting hole 1, a shell 3, ribs and a diversion hole 2. Figure 1 As shown, the flow distribution structure is arranged on the shell 8 of the heat exchanger, the shell 3 is sleeved on the shell 8, and the shell 3 and the shell 8 are connected to form a accommodating chamber. In this embodiment, the accommodating chamber is an annular chamber. The diverter hole 2 is arranged on the shell 8, and the diverter hole 2 connects the accommodating chamber and the inner cavity of the shell 8. A plurality of the diverter holes 2 are evenly arranged circumferentially around the axis of the shell 8. The connecting hole 1 is arranged on the shell 3, and the connecting hole 1 connects the accommodating chamber and the external pipeline. The ribs are arranged on the shell 3 and the shell 8, and the ribs are located in the accommodating chamber. The accommodating chamber can adjust the resistance performance between each diverter hole 2 and the connecting hole 1, enhance the uniformity of the flow distribution of each diverter hole 2, and thus enhance the uniformity of the inlet and outlet flow of the heat exchanger along the circumferential direction.

[0041] Specifically, Figure 1 As shown, the shell side of the heat exchanger is a one-end-in and one-end-out structure, and two flow distribution structures are set on the outer shell 3 to balance the inlet flow and outlet flow of the shell side respectively; in another embodiment, the shell side is a middle-in and two-end-out structure, and three flow distribution structures are set on the outer shell 3 to balance the inlet flow and outlet flow respectively.

[0042] Embodiment 1

[0043] like Figure 2 and Figure 3 As shown, a flow distribution structure is provided with one connecting hole 1, and the axis of the connecting hole is perpendicular to the axis of the shell 8. The connecting hole 1 is located on the outer wall of the shell 3, the diversion holes 2 are evenly distributed on the inner wall of the shell 8, and the ribs are staggered on the inner wall of the shell 3 and the outer wall of the shell 8.

[0044] Preferably, in this embodiment, the preset number of holes is 4, the number n of the diverter holes 2 is a positive multiple of 4, and n≥8; the diverter holes 2 are evenly distributed along the circumference of the axis of the shell 8 and distributed in the four quadrants of the accommodating chamber.

[0045] Preferably, the first numerical range is greater than or equal to 0.7 and less than or equal to 0.8. The sum of the diameters of the plurality of diverter holes 2 is n·D2, the circumferential length of the outer wall of the housing 8 is π·Di, and the ratio of the sum of the diameters D2 of the plurality of diverter holes 2 to the circumferential length of the outer wall satisfies: 0.7≤n·D2 / (π·Di)≤0.8.

[0046] Preferably, the vertical distance between the plane where the axis of the diversion hole 2 is located and the center of the connecting hole 1 is e, and the second numerical range is: (D1+D2) / 2≤e≤2(D1+D2).

[0047] Preferably, the accommodating chamber is symmetrically arranged with the plane defined by the axis of the connecting hole 1 and the axis of the housing 8 as a symmetry plane.

[0048] Preferably, ribs are arranged on the outer wall of the shell 8 and the inner wall of the housing 3, respectively, the ribs extend along the extension direction of the axis of the shell 8, the length direction of the ribs is consistent with the extension direction of the axis of the shell 8, and the length of the ribs is equal to the extension length of the accommodating chamber along the axis of the shell 8. When the width of the ribs is unchanged, the cross-section of the ribs can be circular or polygonal, and the multiple deformation can be various shapes such as rectangular, trapezoidal, triangular, etc.

[0049] Preferably, the ribs include first ribs 4 and second ribs 5 , the first ribs 4 are arranged on the inner wall of the outer shell 3 , and the second ribs 5 are arranged on the outer wall of the shell 8 .

[0050] The first fin 4 and the second fin 5 are respectively arranged on the perpendicular bisector of the line connecting the centers of two adjacent diversion holes 2. Figure 3 As shown, two adjacent flow dividing holes 2 corresponding to the first rib 4 are different from two adjacent flow dividing holes 2 corresponding to the second rib 5 .

[0051] The first ribs 4 and the second ribs 5 are arranged alternately along the circumferential direction of the housing 8 .

[0052] Preferably, the length of the first rib 4 extending radially along the shell 8 is a first height Ho;

[0053] The length of the second fin 5 extending radially along the shell 8 is a second height Hi;

[0054] The ratio of the first height Ho to the second height Hi is within a third numerical range, and the third numerical range is: 1≤Ho / Hi≤2.

[0055] The sum of the first height Ho and the second height Hi is within a fourth numerical range, and the fourth numerical range is: 0.15(Do-Di)≤Hi+Ho≤0.25(Do-Di).

[0056] like Figure 3As shown, at least two first ribs 4 are provided, and at least two first ribs 4 are symmetrically arranged with the plane where the axis of the connecting hole 1 and the axis of the shell 8 are located as a symmetry plane. At least two second ribs 5 are provided, and at least two second ribs 5 are symmetrically arranged with the plane where the axis of the connecting hole 1 and the axis of the shell 8 are located as a symmetry plane.

[0057] Preferably, the ratio of the diameter Do of the outer shell 3 to the diameter Di of the housing 8 is within a fifth numerical range, and the fifth numerical range is: 0.2Di≤(Do-Di)≤0.6Di.

[0058] In the present application, the distance between the axes of the flow dividing hole 2 and the connecting hole 1 is relatively far, thereby preventing the direct scouring of the shell side structure by the inlet high-speed fluid.

[0059] The total area of ​​the diverter holes 2 of the present application is much larger than the area of ​​the connecting hole 1, so the flow velocity of the diverter holes 2 directly connected to the shell side is greatly lower than that of the connecting hole 1, thereby reducing flow-induced vibration and flow abrasion.

[0060] The flow diversion holes 2 of the present application are evenly distributed along the circumference of the shell 8, and the fins adjust the flow resistance. The flow distribution of each flow diversion hole 2 is relatively uniform, so the flow dead zone in the shell inlet and outlet areas is reduced, and the heat transfer of the heat transfer tube is more uniform, so that the required inlet and outlet section length of the shell can be reduced, thereby making the heat exchanger more compact.

[0061] In the present application, the first ribs 4 and the second ribs 5 are arranged in a staggered manner, so that the flow path in the accommodating chamber is wavy, which is convenient for adjusting the resistance characteristics of each hole, and the height of the first ribs 4 and the second ribs 5 is relatively low, which can realize efficient regulation of the flow of each diversion hole 2 under low flow resistance conditions.

[0062] The shell 3 and the internal fins of the present application have a simple structure, are easy to manufacture, and have a small increased volume and good and wide adaptability.

[0063] Embodiment 2

[0064] This embodiment provides a specific embodiment of a flow distribution structure, such as Figure 2 and Figure 3 As shown. Figure 1The heat exchanger shown has a shell 8 with a diameter of 1000mm, and the specific dimensions of the flow distribution structure are as follows: the shell 8 diameter Di is 1000mm, the outer shell 3 diameter Do is 1500mm, the diameter D1 of the connecting hole 1 on the outer shell 3 is 350mm, and there are 16 diverter holes 2 evenly distributed on the shell 8, and the diameter D2 of the diverter hole 2 is 150mm. The vertical distance e between the plane where the axis of the diverter hole 2 is located and the center of the connecting hole 1 is 300mm. There are eight ribs in total, four first ribs 4 are arranged, and the four first ribs 4 are symmetrically arranged with the plane where the axis of the connecting hole 1 and the axis of the shell 8 are located as the symmetry plane, and four second ribs 5 are arranged, and the four second ribs 5 are symmetrically arranged with the plane where the axis of the connecting hole 1 and the axis of the shell 8 are located as the symmetry plane, and the arrangement positions are as shown in the figure. Figure 3 As shown. The first rib 4 and the second rib 5 are staggered along the circumference of the shell 8, the angle α between two adjacent first ribs 4 is 45°, the angle β between two adjacent second ribs 5 is 45°, and the angle γ between the second rib 5 and the first rib 4 is 22.5°. The first height Ho of the first rib 4 is 57 mm, and the second height Hi of the second rib 5 is 42 mm. When the flow distribution structure is applied to the inlet of the heat exchanger, the fluid in the external pipeline flows from the connecting hole 1 into the accommodating chamber between the shell 3 and the shell 8. Under the guidance of the shell 3 and the shell 8, the fluid flows in the accommodating chamber and enters the shell 8 through each diversion hole 2. The commercial software FLUENT is used to numerically analyze the flow distribution performance of the above-mentioned flow distribution structure with or without ribs, and the results are as shown Figure 4 As shown. Figure 4 As shown, the common annular cavity is not provided with ribs, the ribbed annular cavity is provided with ribs, and the number of the diverter holes 2 is different. Figure 4 It can be seen that the deviation between the flow rate of each diverter hole 2 in the ordinary ring cavity and the flow rate average can reach 80%, while the deviation between the flow rate of each diverter hole 2 in the ribbed ring cavity and the flow rate average is only about 20%. It can be seen that due to the regulation of the ribs, the uniformity of the flow distribution of each diverter hole 2 is greatly improved.

[0065] The schematic diagram of the installation of the flow distribution structure of the present application on the heat exchanger is as follows: Figure 1 The inlet fluid flows into the heat exchanger shell 8 from the inlet flow distribution structure 6, and then flows out from the outlet flow distribution structure 7. It can be seen that the flow distribution structure is relatively small compared to the heat exchanger, so it does not increase the occupied space.

[0066] The flow distribution structure of the present application regulates the resistance performance between each diverter hole 2 and the connecting hole 1, strengthens the flow distribution uniformity of each diverter hole 2, and thus enhances the uniformity of the inlet and outlet flow of the heat exchanger along the circumferential direction. The present invention can reduce the flow dead zone and jet scouring caused by uneven inlet and outlet flow, and help to enhance the compactness and safety of the heat exchanger. In addition, the structure is simple, economical, and has practical value.

[0067] In the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0068] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be considered exemplary only.

[0069] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flow distribution structure, characterized in that: Arranged on the shell of the heat exchanger, the flow distribution structure includes: An outer shell, wherein the outer shell is sleeved on the shell, and the outer shell and the shell are connected to form a receiving chamber; A flow diversion hole, wherein the flow diversion hole is arranged on the shell, the flow diversion hole communicates with the accommodating chamber and the inner cavity of the shell, and a plurality of the flow diversion holes are evenly arranged circumferentially around the axis of the shell; A connecting hole, the connecting hole is arranged on the housing, and the connecting hole connects the accommodating chamber and the external pipeline; A rib is provided on the outer shell and the housing, and the rib is located in the accommodating chamber.

2. A flow distribution structure according to claim 1, characterized in that: The ratio of the sum of the diameters of the plurality of diverter holes to the circumferential length of the outer wall of the shell is within a first value range.

3. A flow distribution structure according to claim 1, characterized in that: The number of the diversion holes is greater than or equal to 8, and the number of the diversion holes is a positive multiple of the preset number of holes.

4. A flow distribution structure according to claim 1, characterized in that: A vertical distance between a plane where the axis of the diversion hole is located and the center of the connecting hole is within a second numerical range.

5. A flow distribution structure according to claim 1, characterized in that: The cross section of the rib is circular or polygonal; The ribs extend along an axial extension direction of the housing.

6. A flow distribution structure according to claim 1, characterized in that: The ribs include a first rib and a second rib, the first rib is arranged on the shell, and the second rib is arranged on the shell; The first rib and the second rib are respectively arranged on the perpendicular bisector of the line connecting the centers of two adjacent diversion holes; The first ribs and the second ribs are alternately arranged along the circumferential direction of the shell.

7. A flow distribution structure according to claim 6, characterized in that: The length of the first rib extending in the radial direction of the shell is a first height; The length of the second fin extending in the radial direction of the shell is a second height; The ratio of the first height to the second height is within a third numerical range, and the sum of the first height and the second height is within a fourth numerical range.

8. A flow distribution structure according to claim 6, characterized in that: At least two first ribs are provided, and the at least two first ribs are symmetrically arranged with the plane where the connecting hole axis and the shell axis are located as a symmetry plane; At least two second ribs are provided, and the at least two second ribs are symmetrically arranged with the plane where the connecting hole axis and the shell axis are located as a symmetry plane.

9. A flow distribution structure according to claim 1, characterized in that: A ratio of a diameter of the outer shell to a diameter of the housing is within a fifth range of values.

10. A heat exchanger, characterized in that: A flow distribution structure as described in claims 1 to 9 is arranged thereon.

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