Asymmetric ceramic loop traveling wave thermoacoustic refrigerating system

Abstract

The invention discloses an asymmetric ceramic loop traveling wave thermo-acoustic refrigerating system which comprises four thermo-acoustic nuclear elements and four thermal buffer pipes, the four thermo-acoustic nuclear elements and the four thermal buffer pipes are alternately connected to form an annular loop, and the annular loop is filled with working medium gas. Wherein one or three thermo-acoustic core elements serve as thermo-acoustic engines and are used for absorbing heat energy and converting the heat energy into sound wave energy, the rest thermo-acoustic core elements serve as thermo-acoustic refrigerating machines and are used for absorbing the sound wave energy to refrigerate, heat regenerators are arranged in the thermo-acoustic core elements, and filler bodies in the heat regenerators are high-mesh ultra-thin-wall ceramic bodies. The thermoacoustic conversion efficiency is high, the refrigeration effect is good, when only one thermoacoustic engine is arranged, the refrigeration efficiency is higher, and when three thermoacoustic engines are arranged, lower temperature can be output.

Description

Technical Field

[0001] The invention belongs to the technical field of refrigeration, and in particular relates to an asymmetric ceramic loop traveling wave thermoacoustic refrigeration system. Background Art

[0002] For the loop traveling wave thermoacoustic refrigeration system, theoretical research has found that the heat work generated by the thermoacoustic engine is much greater than the acoustic work consumed by the thermoacoustic refrigerator. GWSwift once proposed that the higher the matching degree between the acoustic work generated by the heat engine and the acoustic work consumed by the refrigerator in the heat-driven thermoacoustic refrigeration system, the more helpful it is to improve the efficiency of the whole machine. At present, the main way to improve the efficiency of the whole machine is to introduce a resonance tube to adjust the phase between the output port of the thermoacoustic engine and the input port of the thermoacoustic refrigerator, but this increases the loss of acoustic work. Achieving a match between the two by consuming acoustic work will lead to an improvement in the efficiency of the whole machine. Restricted; There is currently a document number CN108180673B "A loop heat-driven thermoacoustic refrigeration system" which discloses a thermoacoustic engine driving two thermoacoustic refrigerators for matching, but the two thermoacoustic refrigerators are difficult to completely consume the sound waves generated by their thermoacoustic engine. In addition, the existing regenerators mostly use metal wire mesh fillers, and the gas flow path formed by the regenerator formed by randomly stacking multiple metal wire meshes is irregular, resulting in a large flow resistance and a low thermoacoustic conversion efficiency. Due to technical limitations, high-mesh metal wire meshes are difficult to produce and costly. Summary of the invention

[0003] In order to solve the above technical problems, the object of the present invention is to provide an asymmetric ceramic loop traveling wave thermoacoustic refrigeration system with simple structure, high overall efficiency, high cooling capacity and low cost.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: an asymmetric ceramic loop traveling wave thermoacoustic refrigeration system, comprising four thermoacoustic core elements and four thermal buffer tubes, wherein the four thermoacoustic core elements and the four thermal buffer tubes are alternately connected to form a ring loop, wherein the ring loop is filled with a working fluid gas, wherein one or three of the thermoacoustic core elements serve as a thermoacoustic engine, which is used to absorb thermal energy and convert it into acoustic wave energy, and the remaining thermoacoustic core elements serve as a thermoacoustic refrigerator, which is used to absorb acoustic wave energy for cooling, wherein the thermoacoustic core element has a regenerator, and the filler body in the regenerator is a ceramic body with a high mesh count and an ultra-thin wall.

[0005] The beneficial effect of the above technical solution is that: by setting four thermoacoustic core elements to form a ring loop, one thermoacoustic core element is used as a thermoacoustic engine, and the remaining three are used as thermoacoustic refrigerators, that is, the thermoacoustic engine drives three thermoacoustic refrigerators to cool together. At this time, the three thermoacoustic refrigerators can more fully consume the sound waves generated by the thermoacoustic engine for external cooling, and the thermoacoustic conversion efficiency is high, and the overall efficiency is high. It also has three thermoacoustic core elements as thermoacoustic engines, and the remaining one is used as a thermoacoustic refrigerator. At this time, the three thermoacoustic engines drive one thermoacoustic refrigerator to operate. The thermoacoustic refrigerator can output a lower temperature; in addition, the regenerator adopts a ceramic body with straight through holes evenly distributed as the filler of the regenerator, so that the holes on the filler body are distributed regularly, orderly and straight, which can reduce the flow resistance of the working gas, thereby facilitating the passage of gas micro-clusters and sound waves therebetween. In addition, by increasing the distribution density of the straight through holes on the filler body and achieving ultra-thin walls at the same time, the radial thermal conductivity of the filler body can be improved to overcome the defect of poor radial thermal conductivity of existing ceramic fillers, thereby making the thermoacoustic core element have a higher operating efficiency.

[0006] The filler body in the above technical solution meets at least one of the following conditions: A: The mesh number of the filler body is 10000-60000 mesh; B: The wall thickness of the filler body is 0.01-0.12 mm; C: The material of the filler body includes at least one of alumina, zirconia, cordierite, mullite and silicon carbide; D: The cross-section of the through hole is circular, elliptical, triangular or polygonal; E: The diameter of the filler body is 2-1000 mm; F: The length of the filler body is 2-900 mm; G: The filler body is a monomer or a spliced ​​body.

[0007] The beneficial effect of the above technical solution is that by setting the mesh number of the filler body to 10000-60000 and the wall thickness to 0.01-0.12mm, the distribution density of the straight holes in the filler body can be significantly improved, thereby overcoming the defect of poor thermal conductivity of the filler body made of ceramic material, and the diameter and length of the filler body can be specifically determined according to parameters such as the oscillation frequency and pressure of the working gas.

[0008] The thermoacoustic core element in the above technical solution also includes two heat exchangers, the heat regenerator is sandwiched between the two heat exchangers, and the two heat exchangers are respectively a hot end heat exchanger and a cold end heat exchanger.

[0009] The beneficial effect of the above technical solution is that the two heat exchangers form a temperature difference at both ends of the regenerator, so that the regenerator converts thermal energy into sound wave energy to transfer energy in the ring loop.

[0010] The heat exchanger in the above technical solution includes a pancake-shaped heat exchanger, a serpentine heat exchange channel is arranged in the heat exchanger, and the heat exchanger is densely covered with air holes that pass through both ends of the heat exchanger and are staggered with the heat exchange channel. The air holes are flat holes, and the air holes on the heat exchanger are parallel to each other.

[0011] The beneficial effects of the above technical solution are: its structure is simple and the heat exchange efficiency is low, especially the air holes can also allow the working fluid gas to flow smoothly.

[0012] The thermoacoustic core element in the above technical solution further comprises two trumpet-shaped docking ports, the thick ends of the two docking ports are close to each other and are respectively docked at ends of the two heat exchangers that are away from each other.

[0013] The beneficial effect of the above technical solution is that the thermal buffer tube and the thermoacoustic core element can be connected through the docking interface, especially when the diameter of the thermal buffer tube is smaller than the cross-sectional area of ​​the thermoacoustic core element, the docking interface is used for transitional connection.

[0014] The working gas in the above technical solution meets at least one of the following conditions: A: The working gas is at least one of nitrogen, argon, hydrogen, helium, carbon dioxide and air; B: The pressure of the working gas in the annular loop is 1-150 MPa.

[0015] The beneficial effects of the above technical solution are: it is environmentally friendly and the pressure of the working gas can be set according to the needs of the optimal operating state of the equipment.

[0016] The heat source temperature of the thermoacoustic engine described in the above technical solution is 300-1000K.

[0017] The beneficial effect of the above technical solution is that the thermoacoustic engine can fully utilize various low-grade heat for refrigeration and has good environmental protection.

[0018] The ratio of the cross-sectional area of ​​the thermoacoustic core element to the cross-sectional area of ​​the thermal buffer tube in the above technical solution is 1-25.

[0019] The beneficial effect of the above technical solution is that the ratio of the cross-sectional area of ​​the thermoacoustic core element to the cross-sectional area of ​​the thermal buffer tube can be adjusted as needed, so that the entire loop traveling wave thermoacoustic refrigeration system is in a better operating state.

[0020] The heat buffer tube in the above technical solution comprises a stainless steel tube and a protective sleeve sleeved outside the stainless steel tube.

[0021] The beneficial effect of the above technical solution is that it can avoid heat loss caused by the reciprocating working gas near the hot end heat exchanger exchanging heat with the room temperature environment through the heat buffer tube.

[0022] The regenerator in the above technical solution further comprises a shell tube, and the filler body is filled in the shell tube.

[0023] The beneficial effect of the above technical solution is that the shell tube is used as a filling carrier of the filler body, and the shell tube can be a stainless steel tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to Example 1 of the present invention; Figure 2 This is a schematic diagram of the asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to Example 6 of the present invention; Figure 3 is a schematic structural diagram of a heat exchanger according to an embodiment of the present invention; Figure 4 Schematic diagram of the structure of the thermoacoustic core element in an embodiment of the present invention; Figure 5 is a schematic diagram of an end face of the thermoacoustic core element described in an embodiment of the present invention; Figure 6 4 is a cross-sectional view of the thermal buffer tube according to an embodiment of the present invention.

[0025] In the figure: 1, thermoacoustic nuclear element; 1a, thermoacoustic engine; 1b, thermoacoustic refrigerator; 11, regenerator; 111, filler body; 112, shell and tube; 12, heat exchanger; 12a, hot end heat exchanger; 12b, cold end heat exchanger; 121, heat exchange body; 122, heat exchange channel; 123, air vent; 13, docking port; 2, thermal buffer tube; 21, stainless steel tube; 22, insulation sleeve. DETAILED DESCRIPTION

[0026] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0027] like Figure 1 and Figure 2As shown, this embodiment provides an asymmetric ceramic loop traveling wave thermoacoustic refrigeration system, including four thermoacoustic core elements 1 and four thermal buffer tubes 2, the four thermoacoustic core elements 1 and the four thermal buffer tubes 2 are alternately connected to form a ring loop, the ring loop is filled with a working fluid gas, one or three of the thermoacoustic core elements 1 are used as a thermoacoustic engine 1a, which is used to absorb thermal energy and convert it into sound wave energy, and the remaining thermoacoustic core elements 1 are used as a thermoacoustic refrigerator 1b, which is used to absorb sound wave energy for cooling, the thermoacoustic core element 1 has a regenerator 11, and the filler body 111 in the regenerator 11 is a high-mesh ultra-thin-wall ceramic body, by arranging four thermoacoustic core elements to form a ring loop, and one thermoacoustic core element is used as a thermoacoustic engine, and the remaining three are used as thermoacoustic refrigerators, that is, the thermoacoustic engine drives the three thermoacoustic refrigerators to cool together, at this time the three thermoacoustic The refrigerator can more fully consume the sound waves generated by the thermoacoustic engine for external cooling. It has high thermoacoustic conversion efficiency and high overall efficiency. It also has three thermoacoustic core elements as thermoacoustic engines, and the remaining one as a thermoacoustic refrigerator. At this time, the three thermoacoustic engines drive one thermoacoustic refrigerator to operate, and the thermoacoustic refrigerator can output a lower temperature. In addition, the regenerator uses a ceramic body with straight through holes evenly distributed as the filler of the regenerator, so that the holes on the filler body are distributed regularly, orderly and straight, which can reduce the flow resistance of the working gas, thereby facilitating the passage of gas micro-clusters and sound waves therebetween. In addition, by increasing the distribution density of the straight through holes on the filler body and achieving ultra-thin walling at the same time, the thermal conductivity of the filler body in the radial direction can be improved to overcome the defect of poor thermal conductivity of existing ceramic fillers in the radial direction, thereby making the thermoacoustic core element have a higher operating efficiency.

[0028] In the present embodiment, the distribution density of the through holes on the filler body 112 is increased and ultra-thin walls are achieved at the same time, which can improve the thermal conductivity of the filler body 112 in the radial direction, while the poor thermal conductivity of the ceramic body itself in the axial direction is beneficial to maintaining the temperature difference at both ends of the regenerator (maintaining a large temperature difference at both ends of the regenerator is a necessary condition for thermoacoustic conversion, and the larger the temperature difference, the more significant the thermoacoustic conversion effect). Specifically, the poor thermal conductivity of the filler body in the axial direction is beneficial to reducing its axial heat conduction, thereby maintaining the temperature difference at both ends, while the good thermal conductivity of the filler body in the radial direction can enable efficient heat exchange between the filler body and the working gas, which is beneficial to the thermoacoustic conversion efficiency of the thermoacoustic core element as a whole.

[0029] The filler body 111 in the above technical solution meets at least one of the following conditions: A: The mesh number of the filler body 111 is 10000-60000 mesh (specifically, it can be any value among 10000 mesh, 15000 mesh, 20000 mesh, 25000 mesh, 30000 mesh, 35000 mesh, 40000 mesh, 45000 mesh, 50000 mesh, 55000 mesh and 60000 mesh, or a range corresponding to any two values); B: The wall thickness of the filler body 111 is 0.01-0.12 mm (it can be any value among 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm and 0.12 mm, or a range corresponding to any two values); C: The material of the filler body 111 includes at least one of alumina, zirconia, cordierite, mullite and silicon carbide; D: The cross-section of the through hole is circular, elliptical, triangular or polygonal (preferably, the cross-section of the through hole is square or rectangular); E: the diameter of the filler body 111 is 2-1000 mm (specifically, any value of 2 mm, 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 750 mm, 800 mm, 850 mm, 900 mm, 950 mm and 1000 mm, or a range corresponding to any two values ​​thereof); F: The length of the filler body 111 is 2-900 mm (specifically, any value of 2 mm, 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, 750 mm, 800 mm, 850 mm and 900 mm or a range corresponding to any two values ​​thereof may be ignored); G: The filler body 111 is a single body or a spliced ​​body. By setting the mesh number of the filler body to 10000-60000 and the wall thickness to 0.01-0.12 mm, the distribution density of the straight holes in the filler body can be significantly improved, thereby overcoming the defect of poor radial thermal conductivity of the ceramic filler body. The diameter and length of the filler body can be determined according to parameters such as the oscillation frequency and pressure of the working gas.

[0030] The thermoacoustic core element 1 in the above technical solution also includes two heat exchangers 12, and the regenerator 11 is sandwiched between the two heat exchangers 12. The two heat exchangers 12 are respectively a hot end heat exchanger 12a and a cold end heat exchanger 12b. In this way, the two heat exchangers form a temperature difference at both ends of the regenerator, so that the regenerator converts thermal energy into sound wave energy to transfer energy in a ring loop.

[0031] like Figure 3 As shown, the heat exchanger 12 in the above technical solution includes a pancake-shaped heat exchange body 121, a serpentine heat exchange channel 122 is arranged in the heat exchange body 121, and the heat exchange body 121 is densely covered with air holes 123 that penetrate through both ends of the heat exchange body 121 and are staggered with the heat exchange channel 122. The air holes 123 are flat holes, and the air holes 123 on the heat exchange body 121 are parallel to each other, the structure is simple, and the heat exchange efficiency is low, especially the air holes can also allow the working gas to flow smoothly.

[0032] The thermoacoustic core element 1 in the above technical solution also includes two trumpet-shaped docking ports 13, the thick ends of the two docking ports 13 are close to each other, and are respectively docked at the ends of the two heat exchangers 12 that are away from each other, so that the docking of the thermal buffer tube and the thermoacoustic core element can be satisfied through the docking ports, especially when the diameter of the thermal buffer tube is smaller than the cross-sectional area of ​​the thermoacoustic core element, the docking port is used for transitional docking. A smooth thermal insulation coating can be coated on the outer wall of the docking port in this embodiment, which can be a thermal insulation ceramic coating.

[0033] The working gas in the above technical solution meets at least one of the following conditions: A: The working gas is at least one of nitrogen, argon, hydrogen, helium, carbon dioxide and air; B: The pressure of the working gas in the annular loop is 1-150MPa (it can be any value among 1MPa, 10MPa, 20MPa, 30MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 110MPa, 120MPa, 130MPa, 140MPa and 150MPa, or the corresponding range between any two values), which has good environmental protection performance and the pressure of the working gas can be set according to the needs of the optimal operating state of the equipment.

[0034] The heat source temperature of the thermoacoustic engine 1a described in the above technical solution is 300-1000K (it can be any value among 300K, 400K, 500K, 600K, 700K, 800K, 900K and 1000K or the corresponding range between any two values). The thermoacoustic engine can make full use of various low-grade heat for cooling, and its environmental protection is good.

[0035] In the above technical solution, the ratio of the cross-sectional area of ​​the thermoacoustic core element 1 to the cross-sectional area of ​​the thermal buffer tube 2 is 1-25. In this way, the ratio of the cross-sectional area of ​​the thermoacoustic core element to the cross-sectional area of ​​the thermal buffer tube can be adjusted as needed to ensure that the entire loop traveling wave thermoacoustic refrigeration system is in a better operating state.

[0036] like Figure 6 As shown, the thermal buffer tube 2 in the above technical solution includes a stainless steel tube 21 and a protective sleeve 22 sleeved outside the stainless steel tube 21, so that the reciprocating working gas near the hot end heat exchanger can be prevented from exchanging heat with the room temperature environment through the thermal buffer tube and causing heat loss (the cross-sectional area of ​​the thermoacoustic core element is larger than the cross-sectional area of ​​the thermal buffer tube, which helps to improve the thermoacoustic refrigeration conversion efficiency. A smooth variable-diameter interface is provided at the cross-section of the pipeline to guide the flow, so that the fluid flow is more uniform in the radial direction, so that the edge of the thermoacoustic core element is fully utilized, and the working gas is prevented from eddying and causing the flow loss of the sound wave).

[0037] like Figure 4 and Figure 5 As shown, the regenerator 11 in the above technical solution further includes a shell tube 112, and the filler body 111 is filled in the shell tube 112, so that the shell tube serves as a filling carrier of the filler body, and the shell tube can be a stainless steel tube.

[0038] For a thermoacoustic engine, its hot-end heat exchanger is used to absorb external heat, and its cold-end heat exchanger can circulate tap water to maintain room temperature; for a thermoacoustic refrigerator, its hot-end heat exchanger can circulate tap water to maintain room temperature, and its cold-end heat exchanger can output cold air to the outside.

[0039] Example 1: Figure 1 As shown, this embodiment is a thermoacoustic refrigeration system, which has a thermoacoustic engine and three thermoacoustic refrigerators. The filler of the regenerator corresponding to the thermoacoustic core element in this embodiment is a ceramic filler, the mesh number of the ceramic filler is 10000 mesh, and the wall thickness is 0.05mm. The parameters of the filler body in this embodiment are a diameter of 150mm and a length of 40mm. The pressure of the working gas (helium) in the entire loop traveling wave thermoacoustic refrigeration system is 2.7MPa, and the heat source of the hot end heat exchanger corresponding to the thermoacoustic engine comes from 450K hot oil.

[0040] Embodiments 2 to 5 are all based on embodiment 1, except that the mesh sizes of the filler body 111 are different.

[0041] Comparative Example 1 is also referred to Example 1, except that the mesh number of the filler body is 750 mesh (low mesh number).

[0042] Comparative Example 2 is also based on Example 1, except that the filler body uses wire mesh filler.

[0043] The parameters and performance indicators of specific examples 1 to 5 and comparative examples 1 and 2 are shown in Table 1: Table 1: Parameters and performance indicators of Examples 1 to 5 and Comparative Examples 1 and 2 Serial number Mesh Through porosity / volume porosity Wall thickness / wire diameter (mm) Cooling power(W) Coefficient of Performance COP Example 1 10000 0.58 0.05 5820.1 0.85 Example 2 12100 0.55 0.05 6109.8 1.18 Example 3 20000 0.44 0.05 6187.2 1.20 Example 4 40000 0.28 0.05 6250.1 1.21 Example 5 60000 0.18 0.05 6294.4 1.25 Comparative Example 1 750 0.81 0.05 1001.2 0.23 Comparative Example 2 14400 0.74 0.07 5723.1 0.81 Note: For the filler body 111 made of ceramic material, the through porosity and wall thickness are used for calculation, while for the filler body 111 made of wire mesh material, the volume porosity and wire diameter are used for calculation; 14400 mesh in Comparative Example 2 refers to the number of mesh holes of the metal wire mesh on an inch area, which is converted to 120 meshes on a length of one inch.

[0044] In addition, from the perspective of cost, the cost of a packing body in a single regenerator in Example 1 is less than half of the cost of a single packing body in Comparative Example 1.

[0045] The refrigeration efficiency coefficient COP of Example 2 reaches 1.18, which is about 0.95 higher than that of Comparative Example 1, and the refrigeration power is about 5 times higher. As the ceramic mesh number increases, the thermoacoustic refrigeration efficiency and refrigeration efficiency coefficient also increase significantly, indicating that the increase in the ceramic mesh number improves the thermal conductivity of the ceramic filler along the radial direction, quickly transfers heat, helps to achieve efficient heat exchange, improves the power density of the thermoacoustic refrigeration system, and significantly improves the refrigeration power of the thermoacoustic refrigeration system. The refrigeration efficiency coefficient COP of Example 2 is about 0.37 higher than that of Comparative Example 2. Therefore, for the regenerator, the use of high-mesh ultra-thin-walled ceramic bodies as filler bodies can overcome the defects of large working gas flow resistance, low thermoacoustic conversion efficiency and high cost in the traditional use of metal wire mesh as filler bodies.

[0046] Example 6: Figure 2 As shown, this embodiment is a thermoacoustic refrigeration system, which has three thermoacoustic engines and one thermoacoustic refrigerator. The filler of the regenerator corresponding to the thermoacoustic core element in this embodiment is a ceramic filler, the mesh number of the ceramic filler is 10000 mesh, and the wall thickness is 0.05mm. The parameters of the filler body in this embodiment are a diameter of 150mm and a length of 40mm. The pressure of the working gas (helium) in the entire loop traveling wave thermoacoustic refrigeration system is 2.7MPa, and the heat source of the hot end heat exchanger corresponding to the thermoacoustic engine comes from 630K hot oil.

[0047] Examples 7 to 10 are all based on Example 6, except that the mesh sizes of the filler body 111 are different.

[0048] Comparative Example 3 is also based on Example 1, except that the mesh number of the filler is 750 mesh (low mesh number).

[0049] Comparative Example 4 is also based on Example 1, except that the filler body uses wire mesh filler.

[0050] The parameters and performance indicators of specific examples 7 to 10 and comparative examples 3 and 4 are shown in Table 2: Table 2: Parameters and performance indicators of Examples 1 to 5 and Comparative Examples 1 and 2 The refrigeration efficiency coefficient COP of Example 8 is 0.12, and the refrigeration power is 6200.13. Compared with Comparative Example 4, the refrigeration efficiency coefficient COP is increased by about 0.06, and the refrigeration power is increased by 1027.55W. The refrigeration power and efficiency coefficient of the thermoacoustic refrigeration system increase with the increase of the mesh number of the filler body. Under the condition of unchanged wall thickness, the increase of the mesh number of the ceramic body can improve the thermal conductivity of the ceramic filler in the radial direction, quickly transfer heat, and help to achieve efficient heat exchange, thereby improving the power density of the thermoacoustic refrigeration system and significantly improving the refrigeration power of the thermoacoustic refrigeration system. This further verifies that the performance of the high-mesh ultra-thin-wall ceramic body as a filler body is better than that of the traditional metal wire mesh filler.

[0051] The thermoacoustic core elements in the above-mentioned embodiments and comparative examples are respectively located at four pure traveling wave positions in the typical sound field distribution.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An asymmetric ceramic loop traveling wave thermoacoustic refrigeration system, characterized in that: The invention comprises four thermoacoustic core elements (1) and four thermal buffer tubes (2), wherein the four thermoacoustic core elements (1) and the four thermal buffer tubes (2) are alternately connected to form a ring loop, wherein the ring loop is filled with a working fluid gas, wherein one or three of the thermoacoustic core elements (1) serve as a thermoacoustic engine (1a) for absorbing heat energy and converting it into sound wave energy, and the remaining thermoacoustic core elements (1) serve as a thermoacoustic refrigerator (1b) for absorbing sound wave energy for cooling, wherein the thermoacoustic core element (1) has a regenerator (11), and the filler body (111) in the regenerator (11) is a ceramic body uniformly distributed with straight through holes and having a high mesh number and an ultra-thin wall.

2. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The filler body (111) meets at least one of the following conditions: A: The mesh number of the filler body (111) is 10000-60000 mesh; B: The wall thickness of the filler body (111) is 0.01-0.12 mm; C: The material of the filler body (111) includes at least one of alumina, zirconia, cordierite, mullite and silicon carbide; D: The cross-section of the through hole is circular, elliptical, triangular or polygonal; E: the diameter of the filler body (111) is 2-1000 mm; F: The length of the filler body (111) is 2-900 mm; G: The filler body (111) is a single body or a spliced ​​body.

3. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The thermoacoustic core element (1) further comprises two heat exchangers (12), the heat regenerator (11) being sandwiched between the two heat exchangers (12), and the two heat exchangers (12) are respectively a hot end heat exchanger (12a) and a cold end heat exchanger (12b).

4. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 3, characterized in that: The heat exchanger (12) comprises a pancake-shaped heat exchange body (121), a serpentine heat exchange channel (122) is arranged in the heat exchange body (121), and the heat exchange body (121) is densely covered with air holes (123) that penetrate through both ends of the heat exchange body (121) and are staggered with the heat exchange channel (122), the air holes (123) are flat holes, and the air holes (123) on the heat exchange body (121) are parallel to each other.

5. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 3, characterized in that: The thermoacoustic core element (1) further comprises two trumpet-shaped docking ports (13), the thick ends of the two docking ports (13) being close to each other and respectively docked at ends of the two heat exchangers (12) that are away from each other.

6. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The working gas meets at least one of the following conditions: A: The working gas is at least one of nitrogen, argon, hydrogen, helium, carbon dioxide and air; B: The pressure of the working gas in the annular loop is 1-150 MPa.

7. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The heat source temperature of the thermoacoustic engine (1a) is 300-1000K.

8. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the thermoacoustic core element (1) to the cross-sectional area of ​​the thermal buffer tube (2) is 1-25.

9. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The heat buffer tube (2) comprises a stainless steel tube (21) and a protective sleeve (22) sleeved outside the stainless steel tube (21).

10. The asymmetric ceramic loop traveling wave thermoacoustic refrigeration system according to claim 1, characterized in that: The regenerator (11) further comprises a shell tube (112), and the filler body (111) is filled in the shell tube (112).

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