阅读说明：本技术 一种采用新型压制金属丝网强化换热的回热器 (Adopt regenerator of novel suppression wire mesh intensive heat transfer ) 是由 植晓琴 李国良 曹溶菲 邱利民 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种采用新型压制金属丝网强化换热的回热器,所述的回热器在低温段区域内紧密填充有多个压制金属丝网片,所述的压制金属丝网片采用压薄的金属丝网结构,所述压制金属丝网片中每根金属丝的宽度为20～60μm,厚度为10～25μm。由于是将金属丝网压薄制成的回热填料,相同回热器长度相比于一般的金属丝网回热填料能填更多片,能够提高回热器整体的热容,从而提高低温回热器的回热效率,最终使低温制冷机制冷效率得到提高。(The invention discloses a regenerator for strengthening heat exchange by adopting a novel pressed metal wire mesh, wherein a plurality of pressed metal wire mesh sheets are tightly filled in a low-temperature section area of the regenerator, the pressed metal wire mesh sheets adopt a thinned metal wire mesh structure, the width of each metal wire in the pressed metal wire mesh sheets is 20-60 mu m, and the thickness of each metal wire in the pressed metal wire mesh sheets is 10-25 mu m. Because the metal wire mesh is thinned to form the regenerative filler, compared with the common metal wire mesh regenerative filler, the regenerative filler can be filled with more pieces in the same length of the regenerator, and the overall heat capacity of the regenerator can be improved, so that the regenerative efficiency of the low-temperature regenerator is improved, and finally, the refrigerating efficiency of the low-temperature refrigerator is improved.)

1. The heat regenerator for enhancing heat exchange by adopting the novel pressed metal wire mesh is characterized in that a plurality of pressed metal wire mesh sheets are tightly filled in a low-temperature section area of the heat regenerator, the pressed metal wire mesh sheets adopt a thinned metal wire mesh structure, the width of each metal wire in the pressed metal wire mesh sheets is 20-60 mu m, and the thickness of each metal wire in the pressed metal wire mesh sheets is 10-25 mu m.

2. The regenerator adopting the novel pressed wire mesh for heat exchange enhancement according to claim 1, wherein the pressed wire mesh is made by thinning the wire mesh by a rolling machine, and the diameter of each wire in the wire mesh is 15-45 μm.

3. The regenerator for heat exchange enhancement using a novel pressed wire mesh as claimed in claim 1, wherein the pressed wire mesh sheet is flat woven or inclined woven, and the mesh number per square inch is 250, 270, 280, 300, 325, 350, 363, 370, 400, 500, 600 or 635.

4. The regenerator for heat exchange enhancement by using the novel pressed wire mesh according to claim 1, wherein the pressed wire mesh is circular or annular, and is respectively used for circular or annular regenerators.

5. The regenerator for heat exchange enhancement by using a novel pressed metal wire mesh in accordance with claim 1, wherein the metal wires of the pressed metal wire mesh sheet are stainless steel wires, phosphor bronze wires, copper wires or surface-coated metal wires.

6. The regenerator adopting the novel pressed wire mesh for heat exchange enhancement according to claim 1, wherein the pressed wire mesh is filled in a thin-wall tube at the low temperature section of the regenerator, is tightly stacked and compacted, is firmly clamped by using a stainless steel hard wire mesh, and forms a working temperature zone of the regenerator filling material within the range of 6-50K.

Technical Field

The invention belongs to the technical field of low-temperature heat regenerators, and particularly relates to a heat regenerator for strengthening heat exchange by adopting a novel pressed metal wire mesh.

Background

The heat regenerator is a very key element in the regenerative low-temperature refrigerator, the two ends of the heat regenerator have large temperature difference, cold and hot helium air flows alternately pass through the heat regenerator from different directions to exchange heat with regenerative filler in the heat regenerator, and the regenerative filler stores cold in the process, so that the refrigeration of the refrigerator is finally realized. The cold loss of the low-temperature regenerative refrigerator represented by a Stirling refrigerator and a pulse tube refrigerator usually accounts for more than 50% of the total loss of the low-temperature regenerative refrigerator, and the regenerative loss accounts for the largest part of the losses of the low-temperature regenerative refrigerator. Theoretically, the larger the specific heat capacity of the regenerative filler is, the smaller the regenerative loss is, so that the specific heat capacity of the regenerative filler needs to be focused.

Chinese patent publication No. CN104654676A discloses a nano-coated wire mesh heat regenerator packing, which utilizes the advantage of high specific heat capacity of the nano-coating to form a nano-coating on a common stainless wire mesh to improve the heat capacity of the heat regenerator packing and finally improve the refrigeration efficiency of a cryogenic refrigerator.

Chinese patent publication No. CN101799229A discloses a regenerator structure filled with axial and radial fillers in a mixed manner, which uses conventional wire mesh material, but because the regenerator structure reduces the flow resistance loss, the refrigerating efficiency of the refrigerator is improved.

The conventional heat regenerator filler is generally a common metal wire mesh, such as a stainless steel wire mesh, a phosphor bronze wire mesh and the like, but the specific heat capacity of the two materials is rapidly reduced at low temperature, so that the efficiency of the heat regenerator at low temperature is not high, and the refrigerating efficiency of a refrigerator is influenced. The mesh number, porosity and the like of one filler material are optimized or different conventional materials are mixed and matched, so that the heat regeneration performance at low temperature can be improved to a certain extent. At deep low temperature, the silk screen packing is expected to have small silk diameter, low porosity and larger heat transfer specific surface area, and the common method is to increase the mesh number of the silk screen. However, due to the limitations of the current processing method and the strength of the wire mesh, the wire diameter of the existing product type wire mesh which can be used at low temperature is 18-45 μm, the mesh number is 300-635 meshes, and the porosity is 0.4-0.7, so that a higher mesh number cannot be realized to achieve a smaller porosity. Therefore, in order to increase the specific surface area of the mesh packing by reducing the mesh porosity, new packing structures need to be sought.

Disclosure of Invention

Aiming at the problems that the conventional stainless steel wire mesh equal-heat-regeneration filler is low in heat regeneration efficiency at low temperature and the mesh number of the wire mesh cannot be further improved, the invention provides the heat regenerator for strengthening heat exchange by adopting the novel pressed metal wire mesh, which can improve the integral specific heat capacity of the heat regenerator and reduce heat regeneration loss, thereby improving the refrigeration performance of a low-temperature refrigerator.

The heat regenerator adopts a novel pressed metal wire mesh for heat exchange enhancement, a plurality of pressed metal wire mesh sheets are tightly filled in a low-temperature section area of the heat regenerator, the pressed metal wire mesh sheets adopt a thinned metal wire mesh structure, the width of each metal wire in the pressed metal wire mesh sheets is 20-60 mu m, and the thickness of each metal wire in the pressed metal wire mesh sheets is 10-25 mu m.

According to the invention, the common metal wire mesh is thinned and made into a regular sheet shape, and is filled into the heat regenerator to serve as a regenerative filler, so that the porosity of the pressed wire mesh is smaller, the thickness is smaller, the specific surface area is larger, and more heat regenerators with the same length can be filled, therefore, the integral specific heat capacity of the heat regenerator can be improved, the regenerative loss is reduced, and the refrigerating performance of the low-temperature refrigerator is improved.

According to the invention, the pressed metal wire mesh sheet can be prepared by thinning a metal wire mesh by a rolling machine or other external force extrusion modes, and the diameter of each metal wire in the metal wire mesh is 15-45 μm.

Further, the wire mesh sheet is made by thinning the wire mesh using a spheronizer, and thus has a smaller porosity and a larger specific surface area.

Further, the pressed wire mesh sheet may be plain or twill woven, with a mesh count of 250, 270, 280, 300, 325, 350, 363, 370, 400, 500, 600, 635, or the like, per square inch.

Further, the pressed metal wire mesh sheet is circular or annular and is respectively used for a circular or annular regenerator. The diameter of the round or annular pressed metal wire mesh sheet is 8-35 mm.

Furthermore, the metal wires for pressing the metal wire mesh sheet adopt stainless steel wires, phosphor bronze wires, copper wires or metal wires with surface coatings.

Furthermore, the pressed metal wire mesh sheets are filled into the thin-wall tube of the low-temperature section of the heat regenerator, and are tightly stacked and compacted, so that the formed working temperature zone of the heat regenerator filling is in the range of 6-50K.

Compared with the prior art, the invention has the following beneficial effects:

the pressed wire mesh heat regenerator filler has the advantages of smaller porosity, larger specific surface area, thinner thickness and more filling pieces compared with the common wire mesh in the same length of the heat regenerator, so that the integral specific heat capacity of the heat regenerator filler is improved, the heat regeneration loss is reduced, and the refrigerating efficiency of a low-temperature refrigerator is improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a heat regenerator of the present invention after the heat regenerator has been assembled;

FIG. 2 is a view showing a change in microstructure before and after pressing of a wire mesh;

FIG. 3 is an electron micrograph of a pressed wire mesh sheet (500 mesh plain weave) according to an embodiment of the present invention;

fig. 4 is a graph comparing the performance of the pressed wire mesh regenerator packing of the present invention with that of a conventional stainless steel wire mesh.

In the figure: 1-regenerator tube wall, 2-hard wire mesh, 3-common wire mesh, 4-pressed wire mesh sheet.

Detailed Description

The invention will be described in further detail below with reference to the drawings and examples, which are intended to facilitate the understanding of the invention without limiting it in any way.

Referring to fig. 1, a schematic cross-sectional view of a regenerator after the pressed wire mesh regenerator packing is assembled is shown, which illustrates the assembly of the pressed wire mesh sheets in the regenerator, including regenerator tube wall 1 and hard wire mesh 2. The heat regenerator comprises a regenerator tube wall 1, wherein a common metal wire mesh 3 is filled in a region close to a hot end in the regenerator tube wall 1, a filling temperature zone is more than 50K, a pressed metal wire mesh sheet 4 is filled in a region close to a cold end (a low-temperature section region), the filling temperature zone is 6-50K, and after the heat regenerator tube is installed, the hot end and the cold end are firmly clamped through a stainless steel hard wire mesh 2.

The pressed wire mesh sheet 4 is prepared in the following manner: and rolling the traditional wire mesh with the diameter of 15-45 mu m to thin and flatten the wire mesh, wherein the width of each pressed wire is 20-60 mu m, and the thickness of each pressed wire is 10-25 mu m.

Compared with the original structure, the pressed metal wire mesh sheet 4 manufactured by the method has the characteristics of smaller porosity and larger specific surface area, and can obviously improve the heat capacity of the heat regenerator at low temperature.

A plurality of pressed metal wire mesh sheets 4 are filled into the cold end of the heat regenerator by one sheet, are tightly stacked and compacted, and are firmly clamped by a stainless steel hard wire mesh 2. The metal wire meshes are in close contact with each other, and the inner wall of the heat regenerator tube is in close contact with the metal wire meshes, and helium gas as a working medium flows in the metal wire meshes in an alternating mode and exchanges heat with the metal wire meshes, so that the heat regenerator can realize a heat regenerating function.

The mesh number of each pressed wire mesh sheet 4 is 250, 270, 280, 300, 325, 350, 363, 370, 400, 500, 600, 635 and other common mesh numbers, and the overall diameter of each pressed wire mesh sheet 4 is 8-35 mmμm. The pressed stainless steel wire mesh sheets are filled into a stainless steel heat regenerator thin-wall tube one by one, the mesh sheets are compacted as tightly as possible, gaps are not left between the sheets as far as possible, and the formed heat regenerator filler is suitable for a refrigerator with the working temperature ranging from 6K to 50K.

Fig. 2 shows a microstructure comparison of a conventional screen and a pressed screen. Fig. 3 is an electron micrograph of a pressed wire mesh sheet (500 mesh plain weave) showing the geometry of the pressed wire mesh. Compared with the common wire mesh 3, the pressed wire mesh sheet 4 has the advantages that the arched positions of the stainless steel wires on the two sides are flattened, so that the wire diameter of the wire mesh becomes large, the thickness becomes thin, and the contact between sheets can be tighter.

Because the stainless steel wire mesh is thinned to form the regenerative filler, compared with the common stainless steel wire mesh regenerative filler, the same length of the regenerator can be filled with more pieces, and the overall heat capacity of the regenerator can be improved, so that the regenerative efficiency of the low-temperature regenerator is improved, and finally the cooling efficiency of the low-temperature refrigerator is improved.

The regenerator filled with the novel pressed wire mesh can be applied to G-M refrigerators, Stirling refrigerators, pulse tube refrigerators and the like, and the working temperature range is 6-50K.

The metal wire of the metal wire mesh can be stainless steel wire, phosphor bronze wire, copper wire or metal wire with a surface coating, and in the embodiment, the metal wire mesh is adopted.

The specific manufacturing sequence of the pressed wire mesh heat regenerator filler is as follows:

1) one end of a common stainless steel wire mesh is placed between two cylinders of a rounding machine, the wire mesh slowly and completely passes through a gap between the two cylinders during operation of the machine, the whole thickness is reduced, and the thickness is changed from about 55 mu m to about 42 mu m before and after pressing by taking a common 500-mesh wire mesh as an example.

2) Punching and shearing the stainless steel wire mesh by using a mechanical die or manufacturing a circular or annular pressed stainless steel mesh sheet by using a linear cutting process;

3) and (3) carrying out ultrasonic cleaning on the prepared pressed stainless steel mesh by using acetone to remove oil stains and impurities, then carrying out ultrasonic cleaning by using alcohol, and drying the mesh in a vacuum oven after cleaning.

4) Selecting the mesh with regular and flat shape.

As shown in fig. 4, in order to compare the performance of the common 500-mesh stainless steel wire mesh with the performance of the pressed 500-mesh stainless steel wire mesh obtained through simulation, the set model is set with input sound power of 100W, the temperature of the cold end is 30K, the pulse tube and the regenerator are fixed in size, the common 500-mesh stainless steel wire mesh and the pressed 500-mesh stainless steel wire mesh are respectively filled in a section of the regenerator 15mm close to the cold end, and the maximum refrigerating capacity is obtained by optimizing the transmission tube and the inertia tube. As can be seen from the figure, the refrigerating capacity of the pressed 500-mesh stainless steel wire net is improved by 50-80% compared with that of the common 500-mesh stainless steel wire net under different frequencies.

The embodiments described above are intended to illustrate the technical solutions and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, additions and equivalents made within the scope of the principles of the present invention should be included in the scope of the present invention.