A kind of porous indent augmentation of heat transfer structure printed based on 3D
Technical field
The present invention relates to augmentation of heat transfer structure, particularly relate to a kind of porous indent augmentation of heat transfer structure printed based on 3D.
Background technology
Along with the development that modern industry is at full speed, energy resource consumption is increasing, how to save and little by little receives people with efficent use of resources and pay close attention to the most widely.
In the transmittance process of the energy, the investment of strengthening heat transfer efficiency and reduction equipment for improving whole heat transfer system is most important with operating cost.At present, the main method of augmentation of heat transfer is to improve heat transfer surface structures.
Porous concave inward structure has become prospects for commercial application augmentation of heat transfer structure widely the most.Porous concave inward structure has substantial amounts of fine pore, bigger serface, advantageously forms steam bubble core and improve bubble departure frequency, has well research and using value.
Powder sintering and machining are as the preparation method of common conventional porous structure, due to the restriction of space scale, it is difficult to prepare the structure of porous indent.Therefore, existing porous concave inward structure is affected structure by processing method and is optimized not, affects heat-transfer effect.And 3D printing technique utilizes successively stacking principle structure molding, not only machining accuracy is high, and almost can produce the structure of any shape, and therefore 3D printing technique is that the porous concave inward structure with preferable heat-transfer effect provides possibility.
Summary of the invention
For technical problem present in prior art, it is an object of the invention to: providing a kind of porous indent augmentation of heat transfer structure printed based on 3D, based on 3D printing technique, the porous indent augmentation of heat transfer structure of preparation has more preferable heat-transfer effect.
In order to achieve the above object, the present invention adopts the following technical scheme that
A kind of porous indent augmentation of heat transfer structure printed based on 3D, including metallic matrix and multiple porous element;Porous element is the most closely arranged on metallic matrix;The side of porous element is the concave inward structure to porous element sunken inside, thus between adjacent porous unit, the position of corresponding concave inward structure forms the heat transfer gap of evagination.
Preferred as one, porous element is inverted class hemisphere, class vertebral body or the class platform body structure being fixed on metallic matrix, uniform multiple holes in porous element.Described herein class hemisphere, class vertebral body, class platform body structure, refer to: owing to porous element is successively to process, when precision is less, and interlayer gradient is big, the irregular hemisphere of the shape that therefore formed, vertebral body, stage body.
Preferred as one, porous element is inverted hemisphere, vertebral body or the platform body structure being fixed on metallic matrix, uniform multiple holes in porous element.Specifically, vertebral body includes cone, triangular pyramid, rectangular pyramid etc., and stage body includes round platform, terrace with edge etc..Owing to porous element is successively to process, when precision is bigger, interlayer gradient is little, and the shape naked eyes that therefore formed are it appear that the hemisphere of rule, vertebral body, stage body.
Preferred as one, porous element is formed by metal-powder stacking;Metal-powder is spherical or irregular dendritic morphology.Preferably, particle diameter is 20~80 μm.
Preferred as one, metallic matrix is tabular, and thickness is 1~3mm;The height of porous element is 1~3mm.
Preferred as one, the material of porous element is metal, identical with the material of metallic matrix, for copper, copper alloy, nickel, nickel alloy, aluminium alloy or rustless steel.
Preferred as one, the shapes and sizes of each porous element are the most identical.
Preferred as one, the upper surface of porous element is plane, and the upper surface of all porous elements is respectively positioned on same plane.
A kind of preparation method of the porous indent augmentation of heat transfer structure printed based on 3D, comprise the steps: (1) face on the basis of metal base surface, according to required precision and the size of metal-powder, on datum level, layer overlay thickness is the uniform metal-powder of 20~80 μm;(2) 3D printer uses laser to irradiate the metal-powder sprawled, and in the region lf molding designed, forms ground floor and presses the loose structure of array linear distribution;(3) on the basis of step (2) forms ground floor loose structure, the metal-powder of layer overlay same thickness the most equably, irradiate the metal-powder of the melted second layer with laser, the metal-powder area of this layer of melt molding is larger compared with ground floor area;Later each layer melts area and all amasss larger compared with next aspect, and the thickest the most identical;The rest may be inferred, stacked in multi-layers molding, until forming all of porous element at metal base surface.
Preferred as one, the aperture of porous, shape and arrangement mode that metal-powder arrangement mode in porous element and melt molding go out are formed by software modeling, more controllably print the loose structure of needs through 3D printer;The shapes and sizes in the heat transfer gap between concave inward structure and the porous element of porous element are by software modeling control, more controllably print concave inward structure and the heat transfer gap of needs through 3D printer.
The principle of the present invention is:
This structure includes metallic matrix, with the structure arrays as porous element such as class hemisphere or conoid linearly tight arrangement on metallic matrix.Porous element structure in array is up big and down small, and the side of porous element is the structure of indent, then defines the heat transfer gap of certain evagination between porous element.The present invention uses 3D printer, metallic matrix successively melts certain thickness metal-powder, gradually stack out the array distribution structure of class hemisphere or conoid etc., this structure is the structure that existing machinery processing method can not process, the structure with fine radiating effect never considered for the porous concave inward structure in traditional heat-dissipating field.
Generally speaking, present invention have the advantage that
1.3D printing technique almost can produce the structure of any shape, and including preparing the porous concave inward structure that classical production process is not processed, and it is simple to have preparation process, the advantages such as precision is high and controlled.
2. porous indent augmentation of heat transfer structure increases specific surface area, and beneficially steam bubble aggregation growth forms steam bubble core and improves bubble departure frequency, has excellent enhanced heat transfer performance.
Accompanying drawing explanation
Fig. 1 is the axonometric chart of a kind of porous indent augmentation of heat transfer structure printed based on 3D.
Fig. 2 is the schematic diagram in the heat transfer gap showing concave inward structure and evagination.
Fig. 3 is the sectional view of porous element.
Wherein, 1 is metallic matrix, and 2 is porous element, and 3 is heat transfer gap, and 4 is hole, and 5 is hole.
Detailed description of the invention
Come that the present invention will be further described in detail below.
As it is shown in figure 1, a kind of porous indent augmentation of heat transfer structure printed based on 3D, including: metallic matrix and multiple porous element.Porous element is arranged on metallic matrix in the way of array is the most closely arranged, and forms porous concave inward structure.
Metallic matrix is tabular, and material is copper.
Porous element is inverted hemisphere, and width becomes narrow gradually from top to bottom, therefore forms concave inward structure at the position narrowed.In porous element, there is hole in uniform multiple holes between hole, and the shape in hole can be regular or irregular.The shapes and sizes of each porous element are the most identical, and upper end is plane, and material is copper.
Between adjacent porous unit, the position of corresponding concave inward structure surrounds the heat transfer gap of convex shape, thus forms the heat transfer structure of porous indent between all porous elements and metallic matrix.
The preparation method of a kind of porous indent augmentation of heat transfer structure printed based on 3D, comprises the steps:
(1) size of metallic matrix is 20 × 40mm, and thickness is 2mm.3D printer nozzle uniformly sprays the spherical copper powder that layer overlay thickness is 50 μm on metallic matrix, and copper powder size is in 25~50 μm.
(2) in the region 3D printer lf molding designed, ground floor is formed high with 50 μm, the loose structure that the rod array of diameter 3mm is linearly arranged.
(3) on the basis of ground floor loose structure, then the copper powder of layer overlay same thickness equably, repeat step (2), but the cylindric area of second layer composition loose structure is more than ground floor area;The rest may be inferred, stacked in multi-layers molding, and last layer is that 50 μm are high, the loose structure that the rod array of diameter 5mm is linearly arranged.
As in figure 2 it is shown, the part that porous element is radius 2.5mm spheroid formed, height is 2mm.
As in figure 2 it is shown, adjacent porous unit is in close contact at end face, porous element is constituted concave inward structure by its lower end arc section.
As it is shown on figure 3, copper powder is constituted specific internal loose structure with certain arrangement mode in porous element.
The shape size of porous element and the arrangement mode of copper powder are formed by software modeling all in advance.
In addition to the mode that the present embodiment is mentioned; porous element can be the structure that inverted cone, inverted triangular pyramid iso-cross-section are sequentially reduced from top to bottom; it is alternatively cross section and first reduces the structure increased afterwards; or reduce for several and to increase the composite construction of folded structures again, these variation patterns are the most within the scope of the present invention.
Above-described embodiment is the present invention preferably embodiment; but embodiments of the present invention are also not restricted to the described embodiments; the change made under other any spirit without departing from the present invention and principle, modify, substitute, combine, simplify; all should be the substitute mode of equivalence, within being included in protection scope of the present invention.