CN116702344A - Design method of honeycomb-like heat exchange core capable of realizing fractal flow and heat exchanger - Google Patents
Design method of honeycomb-like heat exchange core capable of realizing fractal flow and heat exchanger Download PDFInfo
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D9/04—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being formed by spirally-wound plates or laminae
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
- F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
- F28F3/04—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element
- F28F3/048—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of ribs integral with the element or local variations in thickness of the element, e.g. grooves, microchannels
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Abstract
A design method of a honeycomb-like heat exchange core capable of realizing fractal flow and a heat exchanger thereof comprise the following steps: s1, determining a basic heat exchange unit of a heat exchange core, S2, constructing a cutting plane control equation of a basic chamber unit, S3, forming a heat exchange core plate assembly and a basic baffle plate, S4, performing lamination assembly on the heat exchange core plate assembly and the basic baffle plate, S5, adding sealing strips, flow guiding strips and the like to obtain the heat exchange core to be tested, S6, judging whether the structural index of the heat exchange core to be tested meets the preset requirement, S7, adding a heat exchange test structure, performing performance index test on a heat exchange core model to be tested after the heat exchange core is added, S8, calculating to obtain a performance index, and judging whether the performance index reaches the preset value. The invention discloses a heat exchange core design method which is based on the deformation and splicing of a honeycomb basic structure, has high compactness, good pressure resistance and high heat exchange power, can realize fractal flow and can also perform efficient heat exchange at high temperature and high pressure.
Description
Technical Field
The invention relates to the technical field of heat exchangers, in particular to a honeycomb-like heat exchange core design method capable of realizing fractal flow and a heat exchanger.
Background
In the face of the demands of the aerospace and industrial equipment fields on high-efficiency heat exchange equipment, the design mode of a microstructure heat exchanger core body with high compactness and high heat exchange power is urgently required. For large heat flux heat exchangers, the solutions currently existing are as follows:
(1) Heat exchange design based on traditional heat exchanger: the plate-fin heat exchanger has wide application in traditional industrial heat dissipation, but is limited by a processing technology, and has limited adaptability to ultra-high temperature and ultra-low temperature environments required during heat exchange with high heat flux density; the spiral tube type heat exchanger is a heat exchange device which utilizes the spiral pipeline to increase the heat transfer effect between fluids, has the advantages of simple structure, easy manufacture, strong adaptability and the like, but has the defects of large weight, easy generation of flow-induced vibration and the like, so that the problems of reducing the weight, reducing the fluid resistance and improving the heat exchange balance of the traditional heat exchange structure still need to be further solved.
(2) Micro-channel heat exchange structure: the micro-channel heat exchange structure is a heat exchange device which increases the heat exchange area and strengthens the heat transfer process by utilizing the micro-sized channels. The most common micro-sweep tube bundle type micro-channel heat exchanger has a structure which can be divided into staggered rows and parallel rows, wherein a cooling medium flows in a tube, and a heating medium flows out of the tube for primary heat exchange. However, when the material is applied to the fields of aerospace and the like, the following problems can be caused due to the limitation of structural characteristics: (1) the volume of the heat exchanger is larger, the residence time of the cold medium is shorter, and the sufficient flow cannot be realized; (2) under the working condition of ultralow temperature or ultrahigh temperature, if the heat exchange capacity is required to be improved, the length of the micro tube bundle needs to be increased, and the problem of flow-induced vibration caused by the long tube bundle also affects the heat exchange process; (3) too many bundles of micro-fine tubes make heat exchange equipment difficult to install. Therefore, further improvements in design are also required for this type of structure.
Disclosure of Invention
The invention aims to provide the honeycomb-like heat exchange core design method and the heat exchanger, which can make up part of defects of the micro-tube heat exchange structure, are beneficial to improving the heat exchange efficiency of the micro-tube heat exchange structure, optimize the structural compactness of the heat exchange core, and enable fluid in a runner inside the heat exchange core to realize fractal flow.
The invention solves the problems in the prior art by adopting the technical scheme that: a design method of a honeycomb-like heat exchange core capable of realizing fractal flow comprises the following steps:
s1, determining a basic heat exchange unit of a heat exchange core body: taking the regular hexagonal prism cavity as the basic heat exchange unit;
s2, constructing a cutting plane control equation of a basic chamber unit with a honeycomb-like three-dimensional structure, and performing parameter adjustment:
s201, establishing a three-dimensional rectangular coordinate system, namely taking a central point of the lower bottom surface of the basic heat exchange unit as an origin, and establishing the three-dimensional rectangular coordinate system; setting the origin coordinate as (0, 0), wherein the three-dimensional rectangular coordinate system is a right-hand rectangular coordinate system;
s202, constructing an outer contour control equation of the basic chamber unit:
step 1, respectively selecting a point on the same height of three non-adjacent side edges of a basic heat exchange unit as a first side edge equal-height point, wherein the distance between the first side edge equal-height point and the lower bottom surface of the basic heat exchange unit is the same; selecting a central point of the lower bottom surface of the basic heat exchange unit, and constructing three different planes by using any two first side edge equal-height points of the four selected points and the central point of the lower bottom surface of the basic heat exchange unit, wherein the three different planes are used as lower cutting planes of the basic heat exchange unit;
The three control equations for the lower cutting plane are as follows:
wherein X, Y and Z are coordinate values of any point in the right-hand rectangular coordinate system in an X axis, a Y axis and a Z axis, l is the side length of a regular hexagon of the lower bottom surface of the basic heat exchange unit, and h is the vertical height from the equal-height point of the first side edge to the central point of the lower bottom surface; the cutting inclination angle of the lower cutting plane is
Step 2, cutting the basic heat exchange unit by utilizing three lower Fang Qiege planes to obtain a basic heat exchange unit with a lower convex wall surface;
step 3, respectively selecting a point on the side edges of the first side edge contour points as second side edge contour points; the distance between the second side edge contour point and the lower bottom surface of the basic heat exchange unit is the same; selecting a central point of the upper bottom surface of the basic heat exchange unit, and constructing three different planes by using any two second side edge equal-height points of the four selected points and the central point of the upper bottom surface of the basic heat exchange unit, wherein the three different planes are used as upper cutting planes of the basic heat exchange unit; the distance between the equal-height point of the second side edge and the lower bottom surface of the basic heat exchange unit is h' =kh, and k is a given coefficient; the coordinates of the central point of the upper bottom surface of the basic heat exchange unit are (0, (k+1) h);
The three control equations for the upper cutting plane are as follows:
cutting inclination angles of three upper cutting planes
Step 4, cutting the basic heat exchange unit with the lower convex wall surface by utilizing three upper Fang Qiege planes to obtain the outer contour of the basic chamber unit with the honeycomb-like three-dimensional structure, wherein the basic chamber unit is provided with the upper convex wall surface and the lower convex wall surface at the same time;
step 5, constructing a plane equation of six sides in the outer contour of the basic chamber unit as follows:
step 6, selecting two opposite side surfaces from six side surfaces of the outer contour of the basic chamber unit to be provided with diffusion through holes as diffusion side wall surfaces; the other two adjacent four side surfaces are provided with a shunt through hole which is used as a shunt side wall surface; obtaining a basic chamber unit;
s3, splicing and cutting the basic chamber units to form a heat exchange core plate assembly and a basic baffle plate:
s301, forming a heat exchange assembly: the heat exchange assembly comprises a first single-layer heat exchange plate and a second single-layer heat exchange plate, and the first single-layer heat exchange plate is spliced at first: splicing the plurality of basic chamber units determined in the step S2 together in a honeycomb arrangement mode along the X-axis direction and the Y-axis direction of the right-hand rectangular coordinate system to form a planar plate structure; during splicing, the diffusion side wall surfaces and the diversion side wall surfaces among the basic chamber units are respectively spliced correspondingly, and the diffusion side wall surfaces among the basic chamber units are spliced in the X-axis direction parallel to the right-hand rectangular coordinate system, so that the diffusion side wall surfaces are parallel to the inflow direction of the cold medium from the X-axis; the split side wall surface of the basic chamber unit forms an included angle of 60 degrees or 120 degrees with the X axis of the right-hand rectangular coordinate system, so that the split side wall surface faces or faces away from the inflow direction of the cold medium from the X axis;
And then splicing the second single-layer heat exchange plates: rotating the basic chamber unit determined in the step S2 clockwise or anticlockwise in the right-hand rectangular coordinate system by 60 degrees by taking the connecting line of the upper vertex and the lower vertex of the basic chamber unit as an axis, and obtaining a second single-layer heat exchange plate according to the splicing mode of the first single-layer heat exchange plate; the flow channels formed by the split flow through holes in the first single-layer heat exchange plate and the second single-layer heat exchange plate are used as main flow split flow channels, and the flow channels formed by the diffusion through holes in the first single-layer heat exchange plate and the second single-layer heat exchange plate are used as diffusion channels;
the second single-layer heat exchange plate is arranged below the first single-layer heat exchange plate in parallel to obtain a heat exchange assembly;
s302, cutting the obtained heat exchange assembly to obtain a heat exchange core plate assembly: cutting two sides of the heat exchange assembly to form a trapezoid tapered heat exchange core plate assembly, wherein a trapezoid short side of the heat exchange core plate assembly is used as an inflow end, and a trapezoid long side is used as an outflow end; an air inlet reserved channel and an air outlet reserved channel are respectively arranged on the trapezoid short side and the trapezoid long side of the heat exchange core plate assembly and are used for connecting an air inlet header and an air outlet header; the air inlet reserved channel is communicated with a shunt through hole at the trapezoid short side of the first single-layer heat exchange plate and the second single-layer heat exchange plate; likewise, the air outlet reserved channel is communicated with the split flow through holes at the trapezoid long sides of the first single-layer heat exchange plate and the second single-layer heat exchange plate, so that the cold medium flowing in the air inlet header pipe can be rapidly diffused in the heat exchange core plate assembly and fractal flows into a plurality of branches;
S303, forming a basic baffle plate: cutting the first single-layer heat exchange plate from the center along a cutting line parallel to the X axis of the right-hand rectangular coordinate system to form a pair of mutually symmetrical basic baffle plates;
s4, stacking and assembling the heat exchange core plate assembly and the basic baffle plate: arranging the heat exchange core plate assemblies in the step S3 in parallel up and down to form an internal heat exchange core body; the basic baffle plates are respectively arranged on the upper side surface and the lower side surface of the internal heat exchange core body in parallel, so that heat medium baffle channels are formed between the basic baffle plates and the adjacent heat exchange core plate assemblies and between the adjacent heat exchange core plate assemblies;
s5, respectively and sequentially installing sealing strips and guide strips on the short sides and the long sides of the heat exchange core plate assembly and the basic baffle plate, wherein the positions avoid the air inlet reserved channels and the air outlet channels; then an air outlet header and an air inlet header are additionally arranged, and the air outlet header is used for communicating the basic baffle plate with the air outlet reserved channels of each heat exchange core plate assembly which are arranged in parallel from top to bottom; the air inlet header communicates the basic baffle plates with air inlet reserved channels of all heat exchange core plate assemblies which are arranged in parallel from top to bottom to obtain a heat exchange core body to be tested;
s6, judging whether the structural index of the heat exchange core to be tested meets the preset requirement, if so, manufacturing a heat exchange core model to be tested according to the heat exchange core to be tested obtained in the step S5, and if not, returning to the step S2 to adjust parameters gamma, gamma ', k in the control equations of the lower cutting plane and the upper cutting plane, wherein gamma is used for controlling the inclination of the lower convex wall surface in the basic chamber unit, and gamma' is used for controlling the inclination of the upper convex wall surface in the basic chamber unit; until the structural index reaches the preset requirement of the structural index; the structural indexes comprise the structural compactness and the component density of the heat exchange core body;
S7, adding a heat exchange test structure outside the heat exchange core model to be tested, and measuring fluid state parameters of the heat exchange core model to be tested:
s701, manufacturing a heat exchange test structure: the heat exchange test structure comprises an inlet cavity section, a stabilizing section, a tapering section and an outlet cavity section, wherein the inlet cavity section and the outlet cavity section are cuboid cavities with two open ends, the stabilizing section comprises two parallel partition boards which are vertically fixed at the two ends of the upper open end of the inlet cavity section, the tapering section comprises two inclined partition boards which are fixed at the two sides of a heat exchange core model to be tested, and the distance between the inclined partition boards is gradually reduced from an air inlet header to an air outlet header;
s702, additionally installing a heat exchange test structure outside a heat exchange core model to be tested: firstly, fixing an inclined baffle plate on the outer side wall of a heat exchange core model to be tested, fixing a parallel baffle plate as a stabilizing section on the end part of the inclined baffle plate at the end part of an air inlet collector, and fixedly connecting the stabilizing section with an inlet cavity section; then the outlet cavity section is fixed at the end part of the inclined partition plate of the outlet header section; finally, cover plates are additionally arranged at the upper and lower open ends of the area surrounded by the outlet cavity section, the taper section, the stabilizing section and the inlet cavity section, and the cover plates are respectively provided with an outflow communication hole and an inflow communication hole which are communicated with the outlet header and the inlet header; the heat exchange test structure is installed;
S703, performance index test is carried out: the performance index testing method comprises the following steps: the inlet cavity section, the outlet cavity section, the outflow communication hole and the inflow communication hole are connected with a fluid sensor; introducing a cooling medium into the inflow communication hole, then introducing a heating medium into the inlet cavity section, enabling the heating medium to enter a heat exchange core model to be tested in the tapered section after passing through the stabilizing section, enabling the heating medium to flow out of the outlet cavity section after fully exchanging heat, obtaining fluid state parameters of the flow process of the heat exchange core model to be tested through the fluid sensor, and obtaining heat exchange power and pressure drop performance indexes through conversion of the fluid state parameters, wherein the fluid state parameters comprise flow field parameters and temperature field parameters;
s8, calculating the fluid state parameters in the step S7 to obtain performance indexes, judging whether the performance indexes reach preset values, and if the performance indexes meet the requirements, obtaining a final heat exchange core body, and ending the design; if not, returning to the step S2 to adjust the gamma, gamma', k of the parameters in the control equations of the lower cutting plane and the upper cutting plane until the fluid state parameters reach preset values; the performance index comprises flow resistance and heat exchange power.
In step S202, the distance between the contour point of the first side edge and the bottom surface of the basic heat exchange unit is less than 1/4 of the height of the side edge.
In step S202, the distance between the second side edge contour point and the upper bottom surface of the basic heat exchange unit is less than 1/4 of the height of the side edge, and the distance between the second side edge contour point and the upper bottom surface of the basic heat exchange unit is the same as the distance between the first side edge contour point and the lower bottom surface of the basic heat exchange unit.
k>3。
In step S3, the total length of the main flow diversion channels in the first single-layer heat exchange plate and the second single-layer heat exchange plate is greater than the length of the diffusion channel.
In step S202, the diffusion through holes and the shunt through holes are both elliptical, and the area of the diffusion through holes is larger than that of the shunt through holes.
The heat exchange core plate assembly is arranged in the direction from the inflow end to the outflow end, and the oval area of the flow dividing through holes is reduced along with the increase of the number of diffusion channel columns.
The heat exchange core plate component and the basic baffle plates are arranged in parallel at equal intervals; the longitudinal spacing distances between the second single-layer heat exchange plate and the first single-layer heat exchange plate, between the adjacent heat exchange core plate assemblies and between the basic baffle plate and the adjacent heat exchange core plate assemblies are all 0.4-2mm.
The fluid sensor includes a speed sensor, a temperature sensor, and a pressure sensor.
A heat exchanger whose heat exchange core is determined by the method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to any one of claims 1 to 9.
The invention has the beneficial effects that: the invention discloses a heat exchanger core design method which is based on the deformation and splicing of a honeycomb basic structure, has high compactness, good pressure resistance and high heat exchange power, can realize fractal flow and can normally perform high-efficiency heat exchange at high temperature and high pressure.
The heat exchanger obtained by the design method has at least the following remarkable advantages:
1. the heat exchange core structure designed by the invention has larger surface area to volume ratio, and the compactness of the obtained heat exchanger is 2500m 2 /m 3 The volume of the heat exchanger required by the same heat exchange capacity can be greatly reduced left and right.
2. The heat exchange core plate assemblies in the heat exchanger core body are symmetrically spliced by the two basic baffle plates, the main processing basic units are the same, the requirements on the arrangement positions of the inlet and the outlet are small, the arrangement of the inlet header and the outlet header at any position can be realized, and the heat exchange applicability is good.
3. The cold medium in the heat exchange core body structure designed by the invention undergoes a series of fractal flow when flowing in the heat exchange unit, and exchanges heat with the external incoming flow heat medium with baffling more fully, so that the heat exchange coefficient is greatly improved compared with the traditional structure.
4. The external heat exchange test section of the heat exchange core structure designed by the invention can be assembled through the transparent acrylic material, and is beneficial to simplifying the heat exchange test mode.
5. According to the invention, the core body is fixed through the air inlet and outlet header and the external test end plate, the connection interface is increased, the vibration caused by the heat exchange core body flow caused by external high-speed incoming air can be reduced, and a better vibration-resistant effect is obtained.
Drawings
FIG. 1 is a schematic diagram of the design flow of the present invention.
Fig. 2 is a diagram of a basic chamber unit generation process in the present invention.
FIG. 3 is a schematic diagram of design parameters of the shunt via in the present invention.
Fig. 4 is a schematic view of the internal splicing mode of the heat exchange core plate assembly in the invention.
Fig. 5 is a schematic view of the heat exchange core plate assembly of the present invention.
FIG. 6 is a schematic view of the basic baffle structure of the present invention.
FIG. 7 is a schematic diagram of a heat exchange core model to be tested in the present invention.
FIG. 8 is an assembly schematic diagram of a heat exchange core model to be tested and a heat exchange test structure according to the present invention.
Fig. 9 is an external view of the present invention after the heat exchange test structure is added.
In the figure: 1-cover plate, 2-outflow communication hole, 3-parallel partition plate, 4-inlet cavity section, 5-outlet cavity section, 6-basic heat exchange unit, 7-inflow communication hole, 8-oblique partition plate, 9-heat exchange core model to be tested, 901-first single-layer heat exchange plate, 902-second single-layer heat exchange plate, 9 a-basic baffle plate, 9 b-heat exchange core plate assembly, 10-inlet header, 10 a-inlet reserved channel, 11-outlet header, 11 a-outlet reserved channel, 12-diversion strip, 13-heat medium baffle channel, 14-sealing strip, 15-basic chamber unit, 15 a-diffusion through hole, 15 b-diversion through hole and upper convex wall surface of 15 c-basic chamber unit; 15 d-lower convex wall of the basic chamber unit, 16-diffusion channel, 17-main flow diversion channel.
Detailed Description
The invention is described below with reference to the drawings and the detailed description:
fig. 1 is a design flow chart of a heat exchange core design method based on a honeycomb three-dimensional structure. A heat exchange core design method based on a honeycomb three-dimensional structure comprises the following steps:
s1, determining a basic heat exchange unit 6 of a heat exchange core body: the regular hexagonal prism cavity is used as a basic heat exchange unit 6;
s2, constructing a cutting plane control equation of the basic chamber unit 15 with the honeycomb-like three-dimensional structure, and performing parameter adjustment:
s201, establishing a three-dimensional rectangular coordinate system, namely taking the center point of the lower bottom surface of the basic heat exchange unit 6 as an origin, and establishing the three-dimensional rectangular coordinate system; setting the origin coordinate as (0, 0), wherein the three-dimensional rectangular coordinate system is a right-hand rectangular coordinate system;
s202, constructing an outer boundary control equation of the basic chamber unit 15:
step 1: as shown in fig. 2: one point is selected as a first side edge contour point on the same height of three non-adjacent side edges of the basic heat exchange unit 6, and preferably, the distance between each first side edge contour point and the lower bottom surface of the basic heat exchange unit 6 is smaller than 1/4 of the height of the side edge. Selecting a central point of the lower bottom surface of the basic heat exchange unit 6, and constructing three different planes by using any two first side edge contour points of the four selected points (three first side edge contour points and the central point of the lower bottom surface of the basic heat exchange unit 6) and the central point of the lower bottom surface of the basic heat exchange unit 6 (namely, points marked as x in fig. 2) as lower cutting planes of the basic heat exchange unit 6;
Wherein, three control equations of the lower cutting plane are constructed as follows:
wherein X, Y and Z are coordinate values of any point in a right-hand rectangular coordinate system in an X axis, a Y axis and a Z axis, l is the side length of a regular hexagon of the lower bottom surface of the basic heat exchange unit 6, and h is the vertical height from the equal-height point of the first side edge to the central point of the lower bottom surface of the basic heat exchange unit 6; the cutting inclination angle of the lower cutting plane is
Step 2: cutting the basic heat exchange unit 6 with three lower cutting planes results in a basic heat exchange unit with a lower convex wall 15d similar to the convex bottom surface of the honeycomb chamber.
Step 3: and a point is respectively selected on the side edges of the first side edge contour points of the basic heat exchange unit 6 as second side edge contour points, preferably, the distance between each second side edge contour point and the upper bottom surface of the basic heat exchange unit 6 is smaller than 1/4 of the height of the side edge, and the distance between each second side edge contour point and the upper bottom surface of the basic heat exchange unit 6 is the same as the distance between each first side edge contour point and the lower bottom surface of the basic heat exchange unit 6. The center point of the bottom surface on the basic heat exchange unit 6 is selected, and three different planes are constructed by using any two second side edge equal-height points of the four selected points and the center (i.e. the point marked as O in fig. 2) point of the bottom surface on the basic heat exchange unit 6, and are used as upper cutting planes of the basic heat exchange unit 6.
Wherein the distance between the second side edge contour point and the lower bottom surface of the basic heat exchange unit 6 is h' =kh, k is a given coefficient, preferably k >3, k is used to control the vertical height of the basic chamber unit. Namely, in the right-hand rectangular coordinate system, the Z-axis coordinates of the equal-height points of the 3 second side edges can be converted into kh, and then the coordinates of the central point of the upper bottom surface of the basic heat exchange unit 6 are (0, (k+1) h);
the three control equations for the upper cutting plane are thus obtained as follows:
wherein X, Y and Z are coordinate values of any point in a right-hand rectangular coordinate system in an X axis, a Y axis and a Z axis, l is the side length of a regular hexagon of the lower bottom surface of the basic heat exchange unit 6, and h is the vertical height from the equal-height point of the first side edge to the central point of the lower bottom surface of the basic heat exchange unit 6; cutting inclination angle of 3 upper cutting planesGamma' mainly controls the inclination of the upper convex wall surface 15c of the top of the future basic chamber unit 15. k is a given coefficient, preferably k>3。
Step 4: cutting the basic heat exchange unit 6 with the lower convex wall surface by using three upper cutting planes to obtain the outer contour of the basic chamber unit 15 with the honeycomb-like three-dimensional structure, which is provided with the upper convex wall surface 15c and the lower convex wall surface 15d at the same time;
step 5, constructing the plane equation of six sides in the outer contour of the basic chamber unit 15 as follows:
Wherein X, Y and Z are coordinate values of any point in a right-hand rectangular coordinate system in an X axis, a Y axis and a Z axis, l is the side length of a regular hexagon of the lower bottom surface of the basic heat exchange unit 6, and h is the vertical height from the equal-height point of the first side edge to the central point of the lower bottom surface of the basic heat exchange unit 6; k is a given coefficient, preferably k >3.
In step 6, two opposite sides of the six sides of the outer contour of the basic chamber unit 15 are selected to be provided with oval diffusion through holes 15a, as shown in fig. 2, in the right-hand rectangular coordinate system established in step S202, the diffusion through holes 15a are provided on two opposite sides of the basic chamber unit 15 in the Y-axis direction, and the four sides adjacent to each other are provided with oval shunt through holes 15b, preferably, the area of the diffusion through holes 15a is larger than the area of the shunt through holes 15 b.
The diversion through holes 15b mainly serve to realize fractal flow and retention of the cold medium in the main flow direction of the in-out flow, and the diffusion through holes 15a serve to realize rapid diffusion of the cold medium in the direction perpendicular to the main flow direction of the in-out flow.
S3, splicing and cutting the basic chamber unit 15 to form a heat exchange core plate assembly 9b and a basic baffle plate 9a: the splicing mode of the heat exchange core plate assembly 9b mainly refers to a regular hexagonal prism back-to-back structure of the honeybee nest, so that the light-weight and high-strength heat exchange structure design is realized.
S301, forming a heat exchange assembly: as shown in fig. 4: the heat exchange assembly comprises a first single-layer heat exchange plate 901 and a second single-layer heat exchange plate 902, wherein the first single-layer heat exchange plate 901 comprises the following components as shown in fig. 5: the plurality of basic chamber units 15 are spliced together in a honeycomb arrangement along the X-axis direction and the Y-axis direction of the right-hand rectangular coordinate system to form a planar plate-like structure. During splicing, the diffusion side wall surfaces of the basic chamber units 15 and the distribution side wall surfaces of the basic chamber units 15 are respectively spliced correspondingly, namely, the diffusion side wall surfaces of the basic chamber units 15 and the diffusion side wall surfaces of the basic chamber units 15 are spliced mutually, and the diffusion side wall surfaces of the basic chamber units 15 are spliced in the direction parallel to the X axis of the right-hand rectangular coordinate system established in the step S201, so that the spliced diffusion side wall surfaces are parallel to the inflow direction of the cold medium from the X axis, and the distribution side wall surfaces of the basic chamber units 15 form an included angle of 60 degrees or 120 degrees with the X axis of the right-hand rectangular coordinate system established in the step S201, so that the distribution side wall surfaces face or face away from the inflow direction of the cold medium from the X axis;
in the right-handed rectangular coordinate system established in the corresponding step S202, after the preset cooling medium flows into each basic chamber unit 15 along the X-axis direction through the split flow holes 15b of the basic chamber units 15, the cooling medium is formed into a fast-diffusing diffusion flow along the Y-axis direction by each diffusion through hole 15a, and the split flow holes 15b enable the cooling medium to form a fractal flow with a longer residence time along the X-axis. The main flow split passage 17 is formed in the first single-layer heat exchange plate 901 due to the mutual communication between the split through holes 15b in the respective basic chamber units 15, and similarly, the diffusion passage 16 is formed in the first single-layer heat exchange plate 901 due to the mutual communication between the diffusion through holes 15a in the respective basic chamber units 15;
The second single-layer heat exchange plate 902 is spliced in the following manner: after the basic chamber unit 15 determined in the step S2 rotates by 60 ° clockwise or counterclockwise in the right-hand rectangular coordinate system established in the step 201 with the connection line between the upper and lower vertexes thereof as an axis (i.e., the basic chamber unit 15 rotates by 60 ° clockwise or counterclockwise around the Z axis in fig. 2), the splicing manner of the first single-layer heat exchange plate 901 is as follows: the rotated basic chamber unit 15 is spliced together in a honeycomb arrangement along the X-axis direction and the Y-axis direction of the right-hand rectangular coordinate system to be a planar plate-like structure. Similarly, during the splicing, the diffusion sidewall surfaces and the split sidewall surfaces between the basic chamber units 15 are respectively spliced correspondingly, and the diffusion sidewall surfaces between the basic chamber units 15 are spliced in the X-axis direction parallel to the right-hand rectangular coordinate system established in the step S201, so that the spliced diffusion sidewall surfaces are parallel to the inflow direction of the cold medium from the X-axis, and the split sidewall surfaces of the basic chamber units 15 form an included angle of 60 ° or 120 ° with the X-axis of the right-hand rectangular coordinate system established in the step S201, so that the split sidewall surfaces face or face away from the inflow direction of the cold medium from the X-axis.
The second single-layer heat exchange plate 902 is placed in parallel under the first single-layer heat exchange plate 901 to obtain the heat exchange core plate assembly 9b. It is preferable that the total length of the main flow distribution channels 17 in the first single-layer heat exchange plate 901 and the second single-layer heat exchange plate 902 is greater than the length of the diffusion channels 16.
S302, cutting the heat exchange assembly obtained in the step S301 to obtain a heat exchange core plate assembly 9b: cutting two sides of the heat exchange assembly (namely cutting the first single-layer heat exchange plate 901 and the second single-layer heat exchange plate 902 in the same manner) to form a trapezoid tapered heat exchange core plate assembly 9b, wherein the trapezoid short sides of the first single-layer heat exchange plate 901 and the second single-layer heat exchange plate 902 after cutting are used as inflow ends, and the trapezoid long sides are used as outflow ends; an air inlet reserved channel 10a and an air outlet reserved channel 11a are respectively arranged on the trapezoid short side and the trapezoid long side of the first single-layer heat exchange plate 901 and the trapezoid long side of the second single-layer heat exchange plate 902 and are used for connecting the air inlet header 10 and the air outlet header 11; the air intake reservation passage 10a communicates with the shunt through holes 15b at the trapezoidal short sides of the first single-layer heat exchange plate 901 and the second single-layer heat exchange plate 902. Likewise, the air outlet reserved channels 11a are communicated with the split through holes 15b at the trapezoid long sides of the first single-layer heat exchange plate 901 and the second single-layer heat exchange plate 902, so that the cold medium flowing in at the air inlet header 10 is rapidly diffused in the heat exchange core plate assembly 9b and fractal flows into multiple branches;
preferably, as shown in fig. 3-4: in the splicing process of the first single-layer heat exchange plate 901 and the second single-layer heat exchange plate 902, the oval aperture of the diffusion through hole 15a of each basic chamber unit 15 is kept consistent in size, and the oval aperture of the distribution through hole 15b of each basic chamber unit 15 is subjected to nonlinear change design, so that the cold medium in the spliced first single-layer heat exchange plate 901 and second single-layer heat exchange plate 902 can flow in a tree-shaped fractal form along the main flow distribution channel 17 in the main flow direction of the cold medium, and can be rapidly diffused along the diffusion channel 16 in the flow direction perpendicular to the main flow direction; preferably, the elliptical apertures of the diffusion through holes 15a and the flow dividing through holes 15b of each column in the main flow dividing passage 17 are varied according to the following parameters:
According to the known technology, a two-dimensional rectangular coordinate system is established according to the following method: as shown in fig. 3: the geometric center of the side wall of the basic chamber unit 15 is taken as an origin, the major axis of the ellipse is taken as an X 'axis, the straight line where the minor axis is positioned is taken as a Y' axis, a two-dimensional coordinate system is established, and X ', Y' are any point coordinates in the coordinate system, so that the general formula of the elliptical through hole is as follows:
a n a long half-axis length (in millimeters) of an ellipse, b n Is elliptical in short half-axis length (in millimeters). Wherein, the liquid crystal display device comprises a liquid crystal display device,
where n is the total number of columns of diffusion channels 16 from the inflow end to the outflow end of the heat exchange core plate assembly 9 b.
For the diversion channel, n is equal to or less than 1 and equal to or less than 16 and is an integer, namely, the size of the plurality of elliptical diversion through holes 15b on the diffusion channel 16 becomes smaller in a nonlinear way with the increase of the number of columns in the direction from the inflow end to the outflow end. For the diffusion through holes 15a for forming the diffusion channels 16, holes as large as possible in area are used, i.e., n=1, a 1 ＝0.8(mm)，b 1 ＝0.3(mm)。
Formation of the internal fractal flow features within the heat exchange core plate assembly 9 b: the cold medium near the air inlet reserved channel 10a in the heat exchange core plate assembly 9b can be rapidly diffused and tree-shaped fractal flow is formed into a plurality of branch flows, after the cold medium is filled between the inflow end plates, the cold medium can relatively uniformly flow into the vicinity of the outlet end in the plate, secondary fractal flow is realized near the air outlet reserved channel 11a, and finally, all branch flows are rapidly collected and summarized and flow out near the air outlet header 11.
S303, formation of basic baffle 9 a: cutting the first single-layer heat exchange plate 901 from the center along the cutting line parallel to the X-axis of the right-hand rectangular coordinate system to form a pair of mutually symmetrical basic baffles 9a, and fig. 6 is a schematic structural view of one basic baffle 9 a;
s4, stacking and assembling the heat exchange core plate assembly 9b and the basic baffle plate 9 a: the heat exchange core plate assemblies 9b in the step S3 are arranged up and down in parallel to form an inner heat exchange core body, and the basic baffle plates 9a are respectively arranged on the upper side surface and the lower side surface of the inner heat exchange core body in parallel. In each group of heat exchange core plate assemblies 9b, the corresponding basic chamber units 15 of the first single layer heat exchange plate 901 and the second single layer heat exchange plate 902 are separated by 60 degrees in position and have a certain distance, and the positions of the first single layer heat exchange plate 901 and the second single layer heat exchange plate 902 in the heat exchange core plate assemblies 9b are designed so that the vertical distances between the first single layer heat exchange plate 901 and the second single layer heat exchange plate 902 are equal everywhere and the vertical distances do not generate structural interference.
It may thus be preferable to arrange the heat exchanger core assemblies 9b equidistantly and parallel to the basic baffle 9a, with the longitudinal spacing distances between the first single-layer heat exchanger plates 901 and the second single-layer heat exchanger plates 902 in the heat exchanger core assemblies 9b, between adjacent heat exchanger core assemblies 9b, between the basic baffle 9a and its adjacent first single-layer heat exchanger plates 901 being set to be equal distances in the range of 0.4-2mm, so that heat medium baffle passages 13 of equal thickness are formed between the basic baffle 9a and the adjacent first single-layer heat exchanger plates 901, between the adjacent heat exchanger core assemblies 9b (as shown in fig. 4).
S5, as shown in fig. 5-6: the heat exchange core plate assembly 9b and the short sides and the long sides of the basic baffle plate 9a are respectively and sequentially provided with a sealing strip 14 with a rectangular section and a guide strip 12 with an isosceles triangle shape at positions avoiding the air inlet reserved channel 10a and the air outlet channel, and the main purpose of installing the guide strip 12 is to reduce the high Wen Lailiu flow resistance of the heat exchange core body model 9 to be tested from the inlet cavity section 4 provided with the heat exchange test structure when the performance index test is carried out later; then, an air outlet header 11 and an air inlet header 10 are additionally arranged, the air inlet header 10 and the air outlet header 11 are fixed with sealing strips 14, wherein the air outlet header 11 is used for communicating the basic baffle plate 9a and the air outlet reserved channels 11a of each heat exchange core plate assembly 9b which are arranged in parallel from top to bottom; the air inlet header 10 is used for communicating the basic baffle plate 9a and the air inlet reserved channels 10a of each heat exchange core plate assembly 9b which are arranged in parallel from top to bottom, and cold medium can circulate to the air outlet header 11 end in the inner cavity of each heat exchange core plate assembly 9b through the air inlet header 10 and the air inlet reserved channels 10a in sequence, so that a heat exchange core body to be tested is obtained as shown in fig. 7;
s6, judging whether structural indexes of the heat exchange core to be tested meet preset requirements, and if so, manufacturing a heat exchange core model 9 to be tested according to the heat exchange core to be tested obtained in the step S5; if not, returning to the step S2 to adjust parameters gamma, gamma ', k in the control equations of the lower cutting plane and the upper cutting plane, wherein gamma is used for controlling the inclination of the lower convex wall surface in the basic chamber unit, and gamma' is used for controlling the inclination of the upper convex wall surface in the basic chamber unit; the structural indexes comprise the structural compactness and the component density of the heat exchange core body; wherein the structure is The compactness and the component density of the heat exchange core are calculated through measuring and calculating the space occupation volume, the solid domain heat exchange surface area and other parameters of the heat exchange core to be tested; the heat exchange compactness is generally required to be more than 1500m 2 /m 3 The density of the heat exchange core body is generally required to be more than 1.5g/cm 3 。
S7, adding a heat exchange test structure outside the heat exchange core model 9 to be tested, measuring parameters of a flow field and a temperature field of the heat exchange core model 9 to be tested after the heat exchange core model 9 to be tested is added, and further converting to obtain heat exchange power and pressure drop performance indexes:
s701, manufacturing a heat exchange test structure: as shown in fig. 8: the heat exchange test structure comprises an inlet cavity section 4, a stabilizing section, a tapering section, an outlet cavity section 5 and a cover plate 1, wherein the inlet cavity section 4 and the outlet cavity section 5 are cuboid cavities with two open ends, the stabilizing section comprises two parallel baffle plates 3 which are vertically fixed at the two ends of the upper open end of the inlet cavity section 4, the tapering section comprises two inclined baffle plates 8 which are fixed at the two sides of a heat exchange core model 9 to be tested, and the distance between the inclined baffle plates 8 is gradually reduced from an air inlet header 10 to an air outlet header 11; according to the heat exchange test structure, the transparent sub-force gram plate is processed in the processing modes of laser cutting, milling and the like to finish manufacturing of the heat exchange test structure. The heat exchange test structure is simple in structure, low in processing cost and capable of achieving visual observation in the performance test process through transparent sub-force gram plate processing.
S702, as in fig. 9: and a heat exchange test structure is additionally arranged outside the heat exchange core model 9 to be tested: firstly, fixing an inclined baffle plate 8 on the outer side wall of a heat exchange core model 9 to be tested, fixing a parallel baffle plate 3 as a stabilizing section on the end part of the inclined baffle plate 8 at the end of an air inlet header 10, and fixedly connecting the stabilizing section with an inlet cavity section 4; then the outlet cavity section 5 is fixed at the end part of the inclined partition plate 8 of the outlet header 11 section; finally, cover plates 1 are additionally arranged at the upper and lower open ends of the area surrounded by the outlet cavity section 5, the taper section, the stabilizing section and the inlet cavity section 4, and the cover plates 1 are respectively provided with an outflow communication hole 2 and an inflow communication hole 7 which are communicated with an outlet header 11 and an inlet header 10; the heat exchange test structure is installed, and the state of fig. 9 is formed from the appearance;
s703, performance index test is carried out: the performance index testing method comprises the following steps: the method comprises the steps that a temperature sensor, a pressure sensor and a speed sensor are connected to an inlet cavity section 4, an outlet cavity section 5, an outflow communication hole 2 and an inflow communication hole 7 in a cover plate 1 in the diagram 9, a cooling medium is connected to the inflow communication hole 7, then a heating medium is connected to the inlet cavity section 4, the heating medium enters a heat exchange core model 9 to be tested in a tapered section after passing through a stabilizing section, after sufficient heat exchange, the heating medium flows out of the outlet cavity section 5, and fluid state parameters such as temperature, pressure and speed in the flowing process of the heat exchange core model 9 to be tested are obtained through the fluid sensors;
S8, calculating performance indexes through the fluid state parameters in the step S7, wherein the performance indexes comprise flow resistance and heat exchange power calculation, and the performance indexes comprise the following steps: the primary heat exchange power calculation formula is obtained by taking the temperature value of a single side of a heat medium or a cold medium in the heat exchange core model 9 to be tested as a reference, and is as follows:
φ＝mc p (T in -T out )
wherein phi is heat exchange power, m represents single-side fluid mass flow, c p Representing the constant pressure specific heat capacity of the side fluid, T representing the side fluid temperature measured experimentally, in representing the fluid inlet end and out representing the fluid outlet end.
The flow resistance (flow resistance) is defined by the total pressure loss coefficient of the heat medium, and is obtained by the following formula:
wherein sigma represents the total pressure loss coefficient of the fluid, p represents the inlet and outlet pressure of the heat medium obtained by test measurement, and subscript a represents the heat medium.
Judging whether the performance index reaches a preset value, namely the total pressure loss coefficient required by the flow resistance is generally smaller than 0.4, and the heat exchange power is generally required to reach 60kW/kg; if the requirements are met, a final heat exchange core body is obtained, and the design is finished; if not, returning to the step S2 to adjust the parameters gamma, gamma', k in the control equations of the lower cutting plane and the upper cutting plane until the fluid state parameters reach preset values;
the heat exchange core of the heat exchanger is designed by adopting the heat exchange core design method.
The heat exchanger and the external test section thereof designed by the invention are subjected to numerical calculation, compared with the existing micro-tube heat exchanger, and the heat exchanger can obtain the heat exchange effect which is better compared with the prior art when the Mach number of the inlet of the side of the heat medium is 1.1Ma under the condition that the heat exchanger occupies the same total space, the total pressure of the outlet, the total temperature of the inlet, the type of cold and hot medium and other heat exchange working conditions, and the heat exchange power of the heat exchanger can be improved by more than 20 percent, wherein the heat exchange coefficient of the side pressure of the heat medium is improved by about 0.15.
The above is a further detailed description of the invention in connection with specific preferred embodiments, and it is not to be construed as limiting the practice of the invention to these descriptions. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (10)
1. The design method of the honeycomb-like heat exchange core capable of realizing fractal flow is characterized by comprising the following steps of:
s1, determining a basic heat exchange unit of a heat exchange core body: taking the regular hexagonal prism cavity as the basic heat exchange unit;
S2, constructing a cutting plane control equation of a basic chamber unit with a honeycomb-like three-dimensional structure, and performing parameter adjustment:
s201, establishing a three-dimensional rectangular coordinate system, namely taking a central point of the lower bottom surface of the basic heat exchange unit as an origin, and establishing the three-dimensional rectangular coordinate system; setting the origin coordinate as (0, 0), wherein the three-dimensional rectangular coordinate system is a right-hand rectangular coordinate system;
s202, constructing an outer contour control equation of the basic chamber unit:
step 1, respectively selecting a point on the same height of three non-adjacent side edges of a basic heat exchange unit as a first side edge equal-height point, wherein the distance between the first side edge equal-height point and the lower bottom surface of the basic heat exchange unit is the same; selecting a central point of the lower bottom surface of the basic heat exchange unit, and constructing three different planes by using any two first side edge equal-height points of the four selected points and the central point of the lower bottom surface of the basic heat exchange unit, wherein the three different planes are used as lower cutting planes of the basic heat exchange unit;
the three control equations for the lower cutting plane are as follows:
wherein X, Y and Z are coordinate values of any point in the right-hand rectangular coordinate system in an X axis, a Y axis and a Z axis, l is the side length of a regular hexagon of the lower bottom surface of the basic heat exchange unit, and h is the vertical height from the equal-height point of the first side edge to the central point of the lower bottom surface; the cutting inclination angle of the lower cutting plane is
Step 2, cutting the basic heat exchange unit by utilizing three lower Fang Qiege planes to obtain a basic heat exchange unit with a lower convex wall surface;
step 3, respectively selecting a point on the side edges of the first side edge contour points as second side edge contour points; the distance between the second side edge contour point and the lower bottom surface of the basic heat exchange unit is the same; selecting a central point of the upper bottom surface of the basic heat exchange unit, and constructing three different planes by using any two second side edge equal-height points of the four selected points and the central point of the upper bottom surface of the basic heat exchange unit, wherein the three different planes are used as upper cutting planes of the basic heat exchange unit; the distance between the equal-height point of the second side edge and the lower bottom surface of the basic heat exchange unit is h' =kh, and k is a given coefficient; the coordinates of the central point of the upper bottom surface of the basic heat exchange unit are (0, (k+1) h);
the three control equations for the upper cutting plane are as follows:
cutting inclination angles of three upper cutting planes
Step 4, cutting the basic heat exchange unit with the lower convex wall surface by utilizing three upper Fang Qiege planes to obtain the outer contour of the basic chamber unit with the honeycomb-like three-dimensional structure, wherein the basic chamber unit is provided with the upper convex wall surface and the lower convex wall surface at the same time;
Step 5, constructing a plane equation of six sides in the outer contour of the basic chamber unit as follows:
step 6, selecting two opposite side surfaces from six side surfaces of the outer contour of the basic chamber unit to be provided with diffusion through holes as diffusion side wall surfaces; the other two adjacent four side surfaces are provided with a shunt through hole which is used as a shunt side wall surface; obtaining a basic chamber unit;
s3, splicing and cutting the basic chamber units to form a heat exchange core plate assembly and a basic baffle plate:
s301, forming a heat exchange assembly: the heat exchange assembly comprises a first single-layer heat exchange plate and a second single-layer heat exchange plate; first, splicing a first single-layer heat exchange plate: splicing the plurality of basic chamber units determined in the step S2 together in a honeycomb arrangement mode along the X-axis direction and the Y-axis direction of the right-hand rectangular coordinate system to form a planar plate structure; during splicing, the diffusion side wall surfaces and the diversion side wall surfaces among the basic chamber units are respectively spliced correspondingly, and the diffusion side wall surfaces among the basic chamber units are spliced in the X-axis direction parallel to the right-hand rectangular coordinate system, so that the diffusion side wall surfaces are parallel to the inflow direction of the cold medium from the X-axis; the split side wall surface of the basic chamber unit forms an included angle of 60 degrees or 120 degrees with the X axis of the right-hand rectangular coordinate system, so that the split side wall surface faces or faces away from the inflow direction of the cold medium from the X axis;
And then splicing the second single-layer heat exchange plates: rotating the basic chamber unit determined in the step S2 clockwise or anticlockwise in the right-hand rectangular coordinate system by 60 degrees by taking the connecting line of the upper vertex and the lower vertex of the basic chamber unit as an axis, and obtaining a second single-layer heat exchange plate according to the splicing mode of the first single-layer heat exchange plate; the flow channels formed by the split flow through holes in the first single-layer heat exchange plate and the second single-layer heat exchange plate are used as main flow split flow channels, and the flow channels formed by the diffusion through holes in the first single-layer heat exchange plate and the second single-layer heat exchange plate are used as diffusion channels;
the second single-layer heat exchange plate is arranged below the first single-layer heat exchange plate in parallel to obtain a heat exchange assembly;
s302, cutting the heat exchange assembly obtained in the step S301 to obtain a heat exchange core plate assembly: cutting two sides of the heat exchange assembly to form a trapezoid tapered heat exchange core plate assembly, wherein a trapezoid short side of the heat exchange core plate assembly is used as an inflow end, and a trapezoid long side is used as an outflow end; an air inlet reserved channel and an air outlet reserved channel are respectively arranged on the trapezoid short side and the trapezoid long side of the heat exchange core plate assembly and are used for connecting an air inlet header and an air outlet header; the air inlet reserved channel is communicated with a shunt through hole at the trapezoid short side of the first single-layer heat exchange plate and the second single-layer heat exchange plate; likewise, the air outlet reserved channel is communicated with the split flow through holes at the trapezoid long sides of the first single-layer heat exchange plate and the second single-layer heat exchange plate, so that the cold medium flowing in the air inlet header pipe can be rapidly diffused in the heat exchange core plate assembly and fractal flows into a plurality of branches;
S303, forming a basic baffle plate: cutting the first single-layer heat exchange plate from the center along a cutting line parallel to the X axis of the right-hand rectangular coordinate system to form a pair of mutually symmetrical basic baffle plates;
s4, stacking and assembling the heat exchange core plate assembly and the basic baffle plate: arranging the heat exchange core plate assemblies in the step S3 in parallel up and down to form an internal heat exchange core body; the basic baffle plates are respectively arranged on the upper side surface and the lower side surface of the internal heat exchange core body in parallel, so that heat medium baffle channels are formed between the basic baffle plates and the adjacent heat exchange core plate assemblies and between the adjacent heat exchange core plate assemblies;
s5, respectively and sequentially installing sealing strips and guide strips on the short sides and the long sides of the heat exchange core plate assembly and the basic baffle plate, wherein the positions avoid the air inlet reserved channels and the air outlet channels; then an air outlet header and an air inlet header are additionally arranged, and the air outlet header is used for communicating the basic baffle plate with the air outlet reserved channels of each heat exchange core plate assembly which are arranged in parallel from top to bottom; the air inlet header communicates the basic baffle plates with air inlet reserved channels of all heat exchange core plate assemblies which are arranged in parallel from top to bottom to obtain a heat exchange core body to be tested;
s6, judging whether the structural index of the heat exchange core to be tested meets the preset requirement, if so, manufacturing a heat exchange core model to be tested according to the heat exchange core to be tested obtained in the step S5, and if not, returning to the step S2 to adjust parameters gamma, gamma ', k in the control equations of the lower cutting plane and the upper cutting plane, wherein gamma is used for controlling the inclination of the lower convex wall surface in the basic chamber unit, and gamma' is used for controlling the inclination of the upper convex wall surface in the basic chamber unit; until the structural index reaches the preset requirement of the structural index; the structural indexes comprise the structural compactness and the component density of the heat exchange core body;
S7, adding a heat exchange test structure outside the heat exchange core model to be tested, and measuring fluid state parameters of the heat exchange core model to be tested:
s701, manufacturing a heat exchange test structure: the heat exchange test structure comprises an inlet cavity section, a stabilizing section, a tapering section and an outlet cavity section, wherein the inlet cavity section and the outlet cavity section are cuboid cavities with two open ends, the stabilizing section comprises two parallel partition boards which are vertically fixed at the two ends of the upper open end of the inlet cavity section, the tapering section comprises two inclined partition boards which are fixed at the two sides of a heat exchange core model to be tested, and the distance between the inclined partition boards is gradually reduced from an air inlet header to an air outlet header;
s702, additionally installing a heat exchange test structure outside a heat exchange core model to be tested: firstly, fixing an inclined baffle plate on the outer side wall of a heat exchange core model to be tested, fixing a parallel baffle plate as a stabilizing section on the end part of the inclined baffle plate at the end part of an air inlet collector, and fixedly connecting the stabilizing section with an inlet cavity section; then the outlet cavity section is fixed at the end part of the inclined partition plate of the outlet header section; finally, cover plates are additionally arranged at the upper and lower open ends of the area surrounded by the outlet cavity section, the taper section, the stabilizing section and the inlet cavity section, and the cover plates are respectively provided with an outflow communication hole and an inflow communication hole which are communicated with the outlet header and the inlet header; the heat exchange test structure is installed;
S703, performance index test is carried out: the performance index testing method comprises the following steps: the inlet cavity section, the outlet cavity section, the outflow communication hole and the inflow communication hole are connected with a fluid sensor; introducing a cooling medium into the inflow communication hole, then introducing a heating medium into the inlet cavity section, enabling the heating medium to enter a heat exchange core model to be tested in the tapered section after passing through the stabilizing section, enabling the heating medium to flow out of the outlet cavity section after fully exchanging heat, obtaining fluid state parameters of the flow process of the heat exchange core model to be tested through the fluid sensor, and obtaining heat exchange power and pressure drop performance indexes through conversion of the fluid state parameters, wherein the fluid state parameters comprise flow field parameters and temperature field parameters;
s8, calculating the fluid state parameters in the step S7 to obtain performance indexes, judging whether the performance indexes reach preset values, and if the performance indexes meet the requirements, obtaining a final heat exchange core body, and ending the design; if not, returning to the step S2 to adjust the gamma, gamma', k of the parameters in the control equations of the lower cutting plane and the upper cutting plane until the fluid state parameters reach preset values; the performance index comprises flow resistance and heat exchange power.
2. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein in step S202, the distance between the first side edge contour point and the bottom surface of the basic heat exchange unit is less than 1/4 of the height of the side edge.
3. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein in step S202, the distance between the second side edge contour point and the bottom surface of the basic heat exchange unit is smaller than 1/4 of the height of the side edge, and the distance between the second side edge contour point and the bottom surface of the basic heat exchange unit is the same as the distance between the first side edge contour point and the bottom surface of the basic heat exchange unit.
4. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein k >3.
5. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein in step S3, the total length of the main flow diversion channels in the first single-layer heat exchange plate and the second single-layer heat exchange plate is greater than the length of the diffusion channels.
6. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein in the step S202, the diffusion through holes and the shunt through holes are both elliptical, and the area of the diffusion through holes is larger than that of the shunt through holes.
7. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 6, wherein the elliptical area of the flow dividing through holes is reduced with the increase of the number of diffusion channels from the inflow end to the outflow end of the heat exchange core plate assembly.
8. The method for designing the honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein the heat exchange core plate assembly and the basic baffle plates are arranged in parallel at equal intervals; the longitudinal spacing distances between the second single-layer heat exchange plate and the first single-layer heat exchange plate, between the adjacent heat exchange core plate assemblies and between the basic baffle plate and the adjacent heat exchange core plate assemblies are all 0.4-2mm.
9. The method for designing a honeycomb-like heat exchange core capable of realizing fractal flow according to claim 1, wherein the fluid sensor comprises a speed sensor, a temperature sensor and a pressure sensor.
10. A heat exchanger, characterized in that the heat exchange core of the heat exchanger is determined by adopting the honeycomb-like heat exchange core design method capable of realizing fractal flow according to any one of claims 1-9.
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| CN117249503A (en) * | 2023-10-10 | 2023-12-19 | 南京御风环境技术有限公司 | Energy-saving dehumidifier with multi-stage heating of regenerated wind |
-
2023
- 2023-04-20 CN CN202310424276.1A patent/CN116702344A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117249503A (en) * | 2023-10-10 | 2023-12-19 | 南京御风环境技术有限公司 | Energy-saving dehumidifier with multi-stage heating of regenerated wind |
| CN117249503B (en) * | 2023-10-10 | 2024-02-09 | 南京御风环境技术有限公司 | Energy-saving dehumidifier with multi-stage heating of regenerated wind |
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