A plate bundle of a plate-fin heat exchanger

Abstract

This invention provides a plate bundle for a plate-fin heat exchanger, relating to the field of heat exchanger technology. It includes a top plate, sealing strips, stacked intermediate plates, and a bottom plate. The stacked intermediate plates, from top to bottom, consist of a perforated upper baffle, a pair of left and right sealing strips, a set of cylindrical turbulence-inducing columns, a perforated lower baffle, a pair of front and rear sealing strips, and another set of cylindrical turbulence-inducing columns, repeatedly stacked to form several cycles. The perforated upper baffle, the pair of left and right sealing strips, and the perforated lower baffle constitute a cold fluid channel, while the perforated lower baffle, the pair of front and rear sealing strips, and the perforated upper baffle of the next cycle constitute a hot fluid channel. The hot and cold fluid channels are stacked alternately. Under the turbulence effect of the cylindrical turbulence-inducing columns and the cross-flow effect between layers caused by the flow inside the cylinder, the working fluid achieves three-dimensional flow within the entire plate-fin heat exchanger, increasing chaotic convection and continuously disrupting and regenerating the thermal boundary layer. The turbulence-inducing columns also enhance the heat transfer area. The heat exchange efficiency of plate-fin heat exchangers can be significantly improved by the combined effects of three mechanisms: chaotic convection, boundary layer disruption, and increased heat transfer area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat exchangers, in particular to a plate bundle of a plate-fin heat exchanger. BACKGROUND

[0002] The plate-fin heat exchanger is widely used in the fields of air separation, petroleum chemical power machinery and aerospace due to its high heat transfer efficiency, compactness, lightness and strong adaptability. The plate-fin heat exchanger is usually composed of a partition plate, a fin, a sealing strip and a flow guide plate. The fin, the flow guide plate and the sealing strip are placed between two adjacent partition plates to form a sandwich, which is referred to as a flow channel. The sandwich is stacked according to different ways of fluid and is brazed into a whole to form a plate bundle. The plate bundle is the core component of the plate-fin heat exchanger.

[0003] In the plate-fin heat exchanger, cold and hot fluid media are distributed in different horizontal flow channels. Adjacent flow channels are separated by partition plates to separate different fluid media and serve as a primary heat transfer surface. The fin, as a secondary surface of the heat exchanger, expands the heat transfer surface area and disturbs the fluid flow, so that the boundary layer is constantly broken and regenerated, thereby achieving the purpose of enhancing heat transfer.

[0004] According to the related art, the inventors find that the cold and hot fluid media are distributed in relatively independent positions in the flow channels separated by the partition plates, and the same fluid media cannot be fully mixed between different stacked flow channels. When heat exchange is performed, it is difficult to avoid a large amount of heat loss. The improved plate bundle structure has a significant impact on improving the heat transfer performance of the heat exchanger. SUMMARY

[0005] The present application aims to solve the problem that the same fluid media cannot be fully mixed between different stacked flow channels in the existing plate-fin heat exchanger. A plate bundle of a plate-fin heat exchanger is provided, which comprises a top plate, a sealing strip, a plurality of stacked intermediate plates and a bottom plate.

[0006] The plurality of stacked intermediate plates are sequentially stacked from top to bottom by a plurality of cycles of an upper layer partition plate with holes, a pair of left and right sealing strips and a group of cylindrical turbulence columns, a lower layer partition plate with holes, a pair of front and rear sealing strips and another group of cylindrical turbulence columns. The upper layer partition plate with holes, the pair of left and right sealing strips and the lower layer partition plate with holes form a cold fluid channel. The lower layer partition plate with holes, the pair of front and rear sealing strips and the upper layer partition plate with holes of the next cycle form a hot fluid channel. The hot fluid channel and the cold fluid channel are alternately stacked. Heat is transferred between the cold fluid and the hot fluid through the upper layer partition plate with holes, the cylindrical turbulence columns and the lower layer partition plate with holes. The group of cylindrical turbulence columns are staggered and arranged at an angle of 45° to the flow directions of the hot fluid and the cold fluid, thereby playing a turbulence role. The hot fluid (cold fluid) can flow from one hot fluid (cold fluid) channel or can pass through the holes in the cylindrical turbulence columns to another hot fluid (or cold fluid) channel separated by a cold fluid (hot fluid) channel, thereby forming a series flow.

[0007] In the improved scheme, the cylindrical turbulence column is interference fitted with the through holes in the upper and lower layer baffles with holes.

[0008] In the improved scheme, the two adjacent groups of cylindrical turbulence columns are staggered and flow through cold fluid and hot fluid respectively.

[0009] In the improved scheme, the top first upper layer baffle with holes and the bottom last lower layer baffle with holes have only one group of holes matched with the cylindrical turbulence columns, and the upper and lower baffles at other intermediate positions have holes matched with the two adjacent groups of cylindrical turbulence columns.

[0010] The technical effects achieved by the present application are as follows:

[0011] 1. The cylindrical turbulence columns staggered between the upper and lower layer baffles with holes can increase the contact area of the fluid working medium with the wall surface of the plate-fin heat exchanger, and improve the overall heat exchange performance of the plate-fin heat exchanger.

[0012] 2. The hot fluid (cold fluid) flows through the hot fluid (cold fluid) channel under the action of the cylindrical turbulence column, forms turbulence, and at the same time passes through the holes in the cylindrical turbulence column to the other hot fluid (or cold fluid) channel separated by the cold fluid (hot fluid) channel, forming a series flow. The turbulence and series flow increase chaotic convection, intensify fluid disturbance, and make the thermal boundary layer constantly break and regenerate, so as to achieve the purpose of enhancing heat exchange.

[0013] 3. The cylindrical turbulence column is interference fitted and connected together with the through holes in the upper and lower layer baffles with holes.

[0014] 4. Compared with the traditional plate-fin heat exchanger, the turbulence and series flow caused by the cylindrical turbulence column make the increase of heat exchange efficiency much greater than the increase of pressure drop at the inlet and outlet, and the influence of the increase of pressure drop can be ignored. The plate bundle of the plate-fin heat exchanger greatly improves the heat exchange efficiency while avoiding the dramatic increase of required pump power, thereby reducing energy consumption and improving economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0016] Figure 1 It is the overall exploded view of the plate bundle of the plate-fin heat exchanger of the present application.

[0017] Figure 2 It isFigure 1 An exploded view of a middle plate of a plate bundle of a plate-fin heat exchanger;

[0018] Figure 3 For Figure 2 A structural schematic view of a hole-bearing upper partition plate of a middle plate;

[0019] Figure 4 For Figure 3 A local enlarged structural schematic view of a point I;

[0020] Figure 5 For Figure 2 A structural schematic view of a hole-bearing lower partition plate of a middle plate;

[0021] Figure 6 For Figure 5 A local enlarged structural schematic view of a point II;

[0022] Figure 7 For Figure 2 A structural schematic view of a cylindrical turbulence column of a middle plate;

[0023] Figure 8 For A structural schematic view of a plate bundle of a plate-fin heat exchanger as a whole;

[0024] Figure 9 Figure 8 For A sectional schematic view of an A-A plane;

[0025] Figure 10 Figure 9 For A local enlarged structural schematic view of a point III;

[0026] Figure 11 For

[0027] A schematic view of a position distribution of a cylindrical turbulence column in a cold fluid flow channel; Figure 12

[0028] For Figure 13 A numerical simulation temperature cloud chart of a hot fluid in a hot fluid flow channel;

[0029] Figure 14 A numerical simulation streamline chart of a hot fluid in a hot fluid flow channel.

[0030] Explanation of reference signs:

[0031] 1 - top plate, 2 - seal, 3 - middle plate, 31 - hole-bearing upper partition plate, 32 - cylindrical turbulence column, 33 - hole-bearing lower partition plate, 4 - bottom plate.

[0032] Specific implementation

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0034] The present embodiment provides a plate bundle of a plate-fin heat exchanger, referring to Figure 1 The plate bundle of the plate-fin heat exchanger comprises a top plate 1, a seal 2, an intermediate plate 3 and a bottom plate 4.

[0035] Referring to Figure 2 The intermediate plate 3 is composed of a perforated upper partition plate 31, a pair of left and right seals 2 and a group of cylindrical turbulence columns 32, a perforated lower partition plate 33, a pair of front and rear seals 2 and another group of cylindrical turbulence columns 32 in turn from top to bottom, and the perforated upper partition plate 31, the pair of left and right seals 2 and the perforated lower partition plate constitute a cold fluid channel, the perforated lower partition plate 33, the pair of front and rear seals 2 and the perforated upper partition plate 31 of the next cycle constitute a cold fluid channel, and the hot fluid channel and the cold fluid channel are alternately stacked. The cylindrical turbulence column 32 is tightly connected with the through holes of the perforated upper partition plate 31 and the perforated lower partition plate 33 in interference fit, which can enhance the structural strength of the plate-fin heat exchanger and improve the pressure resistance. The two adjacent groups of cylindrical turbulence columns 32 are staggered, and the first perforated upper partition plate at the top of the intermediate plate 3 and the last perforated lower partition plate at the bottom have only one group of holes matched with the cylindrical turbulence columns, while the perforated upper partition plates and the perforated lower partition plates at other intermediate positions have holes matched with the two adjacent groups of cylindrical turbulence columns. The seals 2 are arranged in pairs and parallel to the two sides of the cylindrical turbulence columns, and the two adjacent pairs of seals in the up-down direction are in a vertical state. The seal 2 is used for supporting between the upper and lower partition plates and closing the fluid domain, and the arrangement direction of the seal 2 is the same as the direction of the fluid inlet.

[0036] Referring to Figure 3 and Figure 4 The perforated upper partition plate 31 is a square flat plate structure with through holes, the through holes are matched with only one group of cylindrical turbulence columns 32, all the through holes have the same diameter and are distributed on the flat plate in a staggered manner, and the flat plate has an area around the periphery for placing the seal 2.

[0037] Referring to Figure 5 and Figure 6 The perforated lower partition plate 33 is a square flat plate structure with through holes, the through holes are matched with two groups of cylindrical turbulence columns 32, all the through holes have the same diameter and are distributed on the flat plate in a neat manner, and the flat plate has an area around the periphery for placing the seal 2.

[0038] Referring toFigure 7 The outer diameter of the cylindrical turbulence column 32 is the same as the inner diameter of the through hole of the upper layer baffle 31 and the lower layer baffle 33, and the cylindrical turbulence column 32 is tightly connected by interference fit. The inner diameter of the cylindrical turbulence column 32 should not be too small compared with the outer diameter, so as to avoid excessive thermal resistance of the cold fluid and the hot fluid on both sides of the wall of the cylindrical turbulence column.

[0039] Referring to Figure 8 , Figure 9 and Figure 10 , the hot fluid (cold fluid) flows through the hot fluid (cold fluid) passage under the action of the cylindrical turbulence column 32, forms turbulence, and at the same time passes through the inner hole of the cylindrical turbulence column to another hot fluid (or cold fluid) passage separated by the cold fluid (hot fluid) passage, forming a series flow. The turbulence and series flow increase chaotic convection, intensify fluid disturbance, and make the thermal boundary layer constantly break and regenerate. Thus, the cold fluid and the hot fluid can flow in the three-dimensional direction of the plate-fin heat exchanger, and the mixing and heat exchange between the fluids in different layer passages are strengthened.

[0040] Referring to Figure 11 and Figure 12 , the cold fluid flows parallel to the left and right seals 2, and the hot fluid flows parallel to the front and rear seals 2, and the cylindrical turbulence columns 32 are staggered and arranged at an angle of 45° to the flow directions of the hot fluid and the cold fluid.

[0041] Referring to Figure 13 and Figure 14 , after the hot fluid (cold fluid) flows into the hot fluid (cold fluid) passage, it will form a series flow through the inner hole of the cylindrical turbulence column 32 under the action of pressure driving. The hot fluid passage in the middle plate 3 is numerically simulated, and the middle plate 3 where two rows of cylindrical turbulence columns 32 are located is taken as the object, and periodic boundary conditions are set on both sides to reduce the number of grids and the amount of calculation. The cross section where the midpoint of the left cylindrical turbulence column is located is taken to show the fluid heat exchange condition, and it can be seen from the temperature cloud chart and the flow line chart that the hot fluid realizes mixing and heat exchange through the cylindrical turbulence column between two layers of passages, the disturbance effect of the flow field is increased, and the outlet temperature is greatly reduced compared with the inlet temperature.

[0042] In the plate bundle provided in the embodiment, the cylindrical turbulence column 32 increases the contact area between the fluid working medium and the wall of the plate-fin heat exchanger, and improves the overall heat exchange performance of the plate-fin heat exchanger. The turbulence column in the single layer passage can also disturb the fluid flow, so that the boundary layer is constantly broken and regenerated, thereby achieving the purpose of enhancing heat exchange. Compared with the traditional plate-fin heat exchanger, the turbulence and series flow caused by the cylindrical turbulence column make the increase of heat exchange efficiency much greater than the increase of pressure drop, and the influence of the increase of pressure drop can be ignored. The plate bundle of the plate-fin heat exchanger greatly improves the heat exchange efficiency while avoiding the dramatic increase of required pump power, thereby reducing energy consumption and improving economic benefits.

[0043] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference to an item in the claims to be construed as a disavowal of the item, even if the item is not recited in each claim.

[0044] Furthermore, it should be understood that although the description is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be combined appropriately to form other embodiments which can be understood by those skilled in the art.

Claims

1. A plate bundle of a plate-fin heat exchanger, comprising a top plate, a seal bar, a plurality of stacked intermediate plates, and a bottom plate; the upper portion of the stacked intermediate plates is connected to the top plate through the seal bars on both sides to form an upper passage, the lower portion of the stacked intermediate plates is connected to the bottom plate through the seal bars on both sides to form a lower passage, and the upper passage is perpendicular to the lower passage, characterized in that, The laminated intermediate plate is composed of a perforated upper partition plate, two side seals and a cylindrical turbulence column, and a perforated lower partition plate in sequence, and the laminated intermediate plate is repeatedly laminated to form a plurality of cycles; the upper and lower ends of the cylindrical turbulence column are embedded in the perforated upper partition plate and the perforated lower partition plate respectively, the perforated upper partition plate, the two side seals and the perforated lower partition plate are repeatedly cycled to form a plurality of fluid channels, the upper and lower adjacent two channels of the fluid channels are cold and hot fluid channels respectively, and the cold and hot fluid channels are perpendicular to each other and staggered, the cylindrical turbulence columns are arranged in an array, and the upper and lower adjacent cylindrical turbulence columns of the fluid channels are staggered.

2. A plate pack of a plate-fin heat exchanger according to claim 1, characterized in that The direction in which the cylindrical turbulence columns are staggered is 45° to the flow directions of the cold fluid and the hot fluid.

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