Multi-stage Stirling hybrid refrigerator with phase-adjusted coupling between low-temperature ejector and room-temperature ejector

Abstract

The present invention provides a multi-stage Stirling type hybrid structure refrigerator with coupled phase adjustment of a low-temperature displacer and a room-temperature displacer, belonging to the technical field of low-temperature refrigerators, including a refrigerator cold finger, a linear compressor, a room-temperature displacer assembly and a low-temperature displacer assembly. The refrigerator cold finger is a three-stage structure, and the low-temperature displacer assembly is located at the secondary or primary cold end, serving as a phase adjustment mechanism for the low-temperature stage, improving the phase adjustment capability in the deep low-temperature zone, and effectively adjusting the phase distribution in the low-temperature stage regenerator. The high-temperature stage adopts the room-temperature displacer assembly for phase adjustment, adjusting the phase distribution in the high-temperature stage regenerator while recovering the high-temperature stage expansion acoustic work. The present invention not only maintains the advantage of having no moving parts at the deep low-temperature end in contact with the load, but also avoids the reliability problem caused by the excessive length of the multi-stage displacer, forming a hybrid structure refrigerator that can operate efficiently in the deep low-temperature zone.

Description

Technical Field

[0001] The invention belongs to the technical field of low-temperature refrigerators, and specifically discloses a multi-stage Stirling type hybrid structure refrigerator with a low-temperature discharger and a room-temperature discharger coupled and phase-adjusted. Background Art

[0002] Cryogenic refrigeration technology is an important support condition for temperature benchmark measurement, condensed matter physics, quantum computing, astronomical observation, MRI nuclear magnetic resonance, etc. Stirling refrigeration technology and pulse tube refrigeration technology are the current mainstream technologies and are also research hotspots in the field of cryogenic refrigeration.

[0003] Stirling refrigerators are driven by oil-free linear compressors, which have high potential efficiency and high power density. The single-stage refrigeration technology in the temperature range above 40K is mature and has been widely used. However, the multi-stage architecture operating in the deep low temperature range will increase the length of the ejector, making it difficult to ensure the coaxiality between the ejector and the cylinder, resulting in reduced life and reliability. At present, multi-stage Stirling refrigerators cannot reach the temperature range below 10K.

[0004] Compared with the Stirling refrigerator, the Stirling pulse tube refrigerator has no moving parts at the low temperature end, which brings advantages such as low vibration, high reliability and long life; however, the expansion of the cold end dissipates sound and power, and has the defect of low intrinsic efficiency; in addition, traditional phase adjustment mechanisms such as inertial tube gas reservoir and two-way air intake have limited phase adjustment range in the deep low temperature zone, and the sound field distribution is poor, which limits the further improvement of efficiency. At present, the refrigeration efficiency of the multi-stage Stirling pulse tube refrigerator in the liquid helium temperature zone is less than 1%. Summary of the invention

[0005] The present invention provides a multi-stage Stirling type hybrid structure refrigerator with a low temperature displacer and a room temperature displacer coupled and phase-adjusted, which realizes efficient and reliable liquid helium temperature zone refrigeration and avoids the technical problem of wear caused by excessive length of the multi-stage displacer.

[0006] The multi-stage Stirling type hybrid structure refrigerator in which the low temperature discharger and the room temperature discharger are coupled and phase-adjusted includes two structures.

[0007] The first structure includes a refrigerator cold finger, a linear compressor, a room temperature displacer assembly and a low temperature displacer assembly; the refrigerator cold finger is a three-stage structure, including a main room temperature heat exchanger, a primary heat regenerator, a primary cold end heat exchanger, a primary pulse tube, a secondary heat regenerator, a secondary cold end heat exchanger, a secondary pulse tube, a tertiary heat regenerator, a tertiary cold end heat exchanger and a tertiary pulse tube; the linear compressor includes a compressor housing and a compression piston disposed in the compressor housing, and the cavity between the compressor housing and the compression piston is a room temperature compression cavity; the room temperature displacer assembly includes a room temperature cylinder wall, a room temperature piston and a room temperature supporting leaf spring; the low temperature displacer assembly includes a low temperature cylinder wall, a low The room temperature piston and the low temperature support leaf spring; the room temperature compression chamber is connected to the main room temperature heat exchanger; the main room temperature heat exchanger, the first-stage heat regenerator and the first-stage cold end heat exchanger are connected in sequence, the first-stage cold end heat exchanger is connected to the first-stage pulse tube and the second-stage heat regenerator respectively, the second-stage heat regenerator is connected to the second-stage cold end heat exchanger, the second-stage cold end heat exchanger is connected to the channel of the low temperature cylinder wall and the second-stage pulse tube respectively, the channel of the low temperature cylinder wall is connected to the third-stage heat regenerator, the third-stage heat regenerator, the third-stage cold end heat exchanger and the third-stage pulse tube are connected in sequence; the outer side of the room temperature support leaf spring is fixedly connected to the inner wall of the room temperature cylinder wall, and the inner side is fixedly supported by the room temperature piston; the room temperature piston is a stepped structure, and the end faces on both sides are They are respectively a secondary expansion piston end and a room temperature compression piston end. The annular surface between the end faces on both sides is a primary expansion piston end. The primary expansion piston end is connected to the primary pulse tube structure through the channel of the room temperature cylinder wall. The cavity between the primary expansion piston end and the primary pulse tube is the primary expansion cavity. The secondary expansion piston end is connected to the secondary pulse tube through the channel of the room temperature cylinder wall. The cavity between the secondary expansion piston end and the secondary pulse tube is the secondary expansion cavity. The room temperature compression piston end is connected to the room temperature compression cavity. The outer side of the low temperature support leaf spring is fixedly connected to the inner wall of the low temperature cylinder wall, and the inner side fixedly supports the low temperature piston. The end faces on both sides of the low temperature piston are respectively a third expansion piston end and a fourth expansion piston end. The piston end and the low-temperature compression piston end, the three-stage expansion piston end is located in the three-stage pulse tube, and the cavity between the low-temperature compression piston end, the low-temperature cylinder wall and the secondary cold-end heat exchanger is the low-temperature compression cavity; the low-temperature discharger assembly relies on the low-temperature supporting leaf spring stiffness, the low-temperature piston dynamic mass, the mechanical damping and the pressure difference on both sides of the three-stage regenerator to adjust the sound field distribution in the three-stage regenerator; the room temperature discharger assembly relies on the room temperature supporting leaf spring stiffness, the room temperature piston dynamic mass, the mechanical damping, the area difference between the first-stage expansion piston end and the second-stage expansion piston end and the pressure difference on both sides of the first-stage regenerator and the second-stage regenerator to adjust the sound field distribution in the first-stage regenerator and the second-stage regenerator, and at the same time recover the expansion sound work.

[0008] In the first structure, the cold finger of the refrigerator is a fully coaxial structure; the first-stage pulse tube is an annular structure, located between the first-stage regenerator and the second-stage pulse tube.

[0009] In the first structure, gap seals are used between the low-temperature piston and the low-temperature cylinder wall, and between the room-temperature piston and the room-temperature cylinder wall.

[0010] The second structure includes a refrigerator cold finger, a linear compressor, a room temperature ejector assembly and a low temperature ejector assembly; the refrigerator cold finger is a three-stage structure, including a main room temperature heat exchanger, a primary heat regenerator, a primary cold end heat exchanger, a primary pulse tube, a secondary heat regenerator, a secondary cold end heat exchanger, a secondary pulse tube, a tertiary heat regenerator, a tertiary cold end heat exchanger and a tertiary pulse tube; the linear compressor includes a compressor housing and a compression piston disposed in the compressor housing, and the cavity between the compressor housing and the compression piston is a room temperature compression cavity; the room temperature ejector assembly includes a room temperature cylinder wall, a room temperature piston and a room temperature supporting leaf spring; the low temperature ejector assembly includes a low temperature cylinder wall, a low The room temperature piston and the low temperature support leaf spring; the room temperature compression chamber is connected to the main room temperature heat exchanger; the main room temperature heat exchanger, the first-stage heat exchanger and the first-stage cold end heat exchanger are connected in sequence, the first-stage cold end heat exchanger is respectively connected to the channel of the low temperature cylinder wall and the first-stage pulse tube, the channel of the low temperature cylinder wall is connected to the second-stage heat exchanger, the second-stage heat exchanger is connected to the second-stage cold end heat exchanger, the second-stage cold end heat exchanger is respectively connected to the second-stage pulse tube and the third-stage heat exchanger, the third-stage heat exchanger, the third-stage cold end heat exchanger and the third-stage pulse tube are connected in sequence; the outer side of the room temperature support leaf spring is fixedly connected to the inner wall of the room temperature cylinder wall, and the inner side is fixedly supported to the room temperature piston; the end faces on both sides of the room temperature piston are respectively the first The expansion piston end and the room temperature compression piston end, the first-stage expansion piston end is connected to the first-stage pulse tube through the channel of the room temperature cylinder wall, the cavity between the first-stage expansion piston end and the first-stage pulse tube is the first-stage expansion cavity, and the room temperature compression piston end is connected to the room temperature compression cavity; the outer side of the low-temperature support leaf spring is fixedly connected to the inner wall of the low-temperature cylinder wall, and the inner side is fixed to support the low-temperature piston; the low-temperature piston is a stepped structure, and the end faces on both sides are respectively the third-stage expansion piston end and the low-temperature compression piston end, and the annular surface between the end faces on both sides is the second-stage expansion piston end, the third-stage expansion piston end is located in the third-stage pulse tube, and the second-stage expansion piston end and the second-stage pulse tube are connected through the channel of the low-temperature cylinder wall. The cavity between the secondary expansion piston end and the secondary pulse tube is the secondary expansion cavity, and the cavity between the low-temperature compression piston end, the low-temperature cylinder wall and the primary cold-end heat exchanger is the low-temperature compression cavity; the low-temperature discharger assembly relies on the low-temperature supporting leaf spring stiffness, the low-temperature piston dynamic mass, the mechanical damping, the area difference between the secondary expansion piston end and the tertiary expansion piston end, and the pressure difference on both sides of the secondary regenerator and the tertiary regenerator to adjust the sound field distribution in the secondary regenerator and the tertiary regenerator; the room temperature discharger assembly relies on the room temperature supporting leaf spring stiffness, the room temperature piston dynamic mass, and the pressure difference on both sides of the mechanical damping primary regenerator to adjust the sound field distribution in the primary regenerator and recover the expansion sound work at the same time.

[0011] In the second structure, the cold finger of the refrigerator is a fully coaxial structure; the secondary pulse tube is a ring structure, located between the secondary regenerator and the tertiary pulse tube.

[0012] In the second structure, gap seals are used between the low-temperature piston and the low-temperature cylinder wall, and between the room-temperature piston and the room-temperature cylinder wall.

[0013] The multi-stage Stirling type hybrid structure refrigerator with low temperature ejector and room temperature ejector coupled and phase-adjusted provided by the present invention has the following advantages compared with the prior art:

[0014] The high-temperature stage adopts room-temperature displacer components for phase adjustment and acoustic power recovery, and the low-temperature stage adopts low-temperature displacer components for phase adjustment. Compared with the traditional phase adjustment mechanism, it has stronger phase adjustment ability and provides suitable acoustic field conditions for the regenerator. Compared with the multi-stage integrated displacer in the multi-stage Stirling refrigerator, the independent displacer between stages makes the phase adjustment more flexible and adapts to the needs of load changes. In addition, the phase adjustment displacer of the low-temperature stage is only located at the hot end of the low-temperature stage, which can further reduce the pulse tube loss of the low-temperature stage and improve the refrigeration efficiency. At the same time, it maintains the advantage of no moving parts at the deep low-temperature end in contact with the load, and avoids the reliability problems caused by the excessive length of the displacer in the multi-stage Stirling refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A cross-sectional view of the structure of Embodiment 1 of the present invention

[0017] Figure 2 A cross-sectional view of a low temperature ejector assembly in Example 1 of the present invention

[0018] Figure 3 A cross-sectional view of the structure of Embodiment 2 of the present invention

[0019] Figure 4 It is a cross-sectional view of the low-temperature ejector assembly in Example 2 of the present invention.

[0020] In the figure: 1. main room temperature heat exchanger; 2. primary heat regenerator; 3. primary cold end heat exchanger; 4. secondary heat regenerator; 5. secondary cold end heat exchanger; 6. tertiary heat regenerator; 7. tertiary cold end heat exchanger; 8. tertiary pulse tube; 9. low temperature discharger assembly; 10. secondary pulse tube; 11. primary pulse tube; 12. compression piston; 13. room temperature cylinder wall; 14. room temperature piston; 15. room temperature support leaf spring; 16. secondary expansion piston end; 17. primary expansion piston end; 18. room temperature compression piston end; 19. low temperature piston; 20. low temperature cylinder wall; 21. low temperature support leaf spring; 22. tertiary expansion piston end; 23. low temperature compression piston end; 24. compressor housing. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1

[0023] The present embodiment provides a multi-stage Stirling type hybrid structure refrigerator with a low-temperature displacer and a room-temperature displacer coupled and phase-adjusted, including a refrigerator cold finger, a linear compressor, a room-temperature displacer assembly and a low-temperature displacer assembly 9; the refrigerator cold finger is a three-stage structure, including a main room-temperature heat exchanger 1, a primary heat exchanger 2, a primary cold-end heat exchanger 3, a primary pulse tube 11, a secondary heat exchanger 4, a secondary cold-end heat exchanger 5, a secondary pulse tube 10, a tertiary heat exchanger 6, a tertiary cold-end heat exchanger 7 and a tertiary pulse tube 8; the linear compressor includes a compressor housing 24 and a compression piston 12 disposed in the compressor housing 24, and the compressor housing 24 and the compression piston 1 2 is a room temperature compression chamber; the room temperature ejector assembly includes a room temperature cylinder wall 13, a room temperature piston 14 and a room temperature support leaf spring 15; the low temperature ejector assembly 9 includes a low temperature cylinder wall 20, a low temperature piston 19 and a low temperature support leaf spring 21; the room temperature compression chamber is connected to the main room temperature heat exchanger 1; the main room temperature heat exchanger 1, the primary heat exchanger 2 and the primary cold end heat exchanger 3 are connected in sequence, the primary cold end heat exchanger 3 is connected to the primary pulse tube 11 and the secondary heat exchanger 4 respectively, the secondary heat exchanger 4 is connected to the secondary cold end heat exchanger 5, the secondary cold end heat exchanger 5 is connected to the channel of the low temperature cylinder wall 20 and the secondary pulse tube 10 respectively, the low temperature cylinder wall The channel of 20 is connected with the third-stage heat exchanger 6, and the third-stage heat exchanger 6, the third-stage cold end heat exchanger 7, and the third-stage pulse tube 8 are connected in sequence; the outer side of the room temperature support leaf spring 15 is fixedly connected with the inner wall of the room temperature cylinder wall 13, and the inner side is fixedly supported by the room temperature piston 14; the room temperature piston 14 is a stepped structure, and the end faces on both sides are respectively the secondary expansion piston end 16 and the room temperature compression piston end 18, and the annular surface between the end faces on both sides is the primary expansion piston end 17, and the primary expansion piston end 17 is connected with the primary pulse tube 11 through the channel of the room temperature cylinder wall 13, and the cavity between the primary expansion piston end 17 and the primary pulse tube 11 is the primary expansion cavity, and the secondary The expansion piston end 16 is connected to the secondary pulse tube 10 through the channel of the room temperature cylinder wall 13, the cavity between the secondary expansion piston end 16 and the secondary pulse tube 10 is the secondary expansion cavity, and the room temperature compression piston end 18 is connected to the room temperature compression cavity; the outer side of the low temperature support leaf spring 21 is fixedly connected to the inner wall of the low temperature cylinder wall 20, and the inner side fixedly supports the low temperature piston 19; the end faces of the two sides of the low temperature piston 19 are respectively the tertiary expansion piston end 22 and the low temperature compression piston end 23, the tertiary expansion piston end 22 is located in the tertiary pulse tube 8, and the cavity between the low temperature compression piston end 23, the low temperature cylinder wall 20 and the secondary cold end heat exchanger 5 is the low temperature compression cavity.

[0024] In the above-mentioned multi-stage Stirling type hybrid structure refrigerator, the cold fingers of the refrigerator are of a fully coaxial structure; the primary pulse tube 11 is of an annular structure and is located between the primary regenerator 2 and the secondary pulse tube 10.

[0025] In the above-mentioned multi-stage Stirling type hybrid structure refrigerator, gap sealing is adopted between the low-temperature piston 19 and the low-temperature cylinder wall 20, and between the room-temperature piston 14 and the room-temperature cylinder wall 13.

[0026] Working principle: The compression piston 12 of the linear compressor reciprocates, and the working medium helium forms periodic pressure fluctuations in the system. The working medium passes through the room temperature compression chamber, the main room temperature heat exchanger 1, the first stage regenerator 2, and the first stage cold end heat exchanger 3, and the temperature gradually decreases. A split occurs at the first stage cold end heat exchanger 3, and a part enters the first stage expansion chamber formed by the first stage pulse tube 11, channel I and the first stage expansion piston end 17 of the room temperature ejector assembly, and the rest enters the second stage regenerator 4 and the second stage cold end heat exchanger 5. The temperature decreases again, and a split occurs again at the second stage cold end heat exchanger 5, and a part enters the second stage pulse tube 10, channel II and the second stage expansion piston end 16 of the room temperature ejector assembly. The rest enters the third stage regenerator 6 and the third stage cold end heat exchanger 7, and the temperature drops to a deep low temperature, and then enters between the third stage pulse tube 8 and the third stage expansion piston end 22 of the low temperature ejector assembly 9. The working fluid helium flows in an alternating manner in the system, and the room temperature ejector assembly and the low temperature ejector assembly 9 serve as phase adjustment mechanisms to adjust the phase difference between the pressure wave and the mass flow in the system.

[0027] The low temperature displacer assembly 9 adjusts the sound field distribution in the three-stage regenerator 6 by relying on the stiffness of the low temperature support leaf spring 21, the dynamic mass of the low temperature piston 19, the mechanical damping, and the pressure difference on both sides of the three-stage regenerator 6. The room temperature displacer assembly adjusts the phase distribution in the first-stage regenerator 2 and the second-stage regenerator 4 by relying on the stiffness of the room temperature support leaf spring 15, the dynamic mass of the room temperature piston 14, the mechanical damping, the area difference between the first-stage expansion piston end 17 and the second-stage expansion piston end 16, and the pressure difference on both sides of the first-stage regenerator 2 and the second-stage regenerator 4, and at the same time recovers the expansion acoustic work at the ends of the first-stage pulse tube 11 and the second-stage pulse tube 10 to the compression chamber. The whole system realizes high efficiency and long life operation in the deep low temperature zone.

[0028] Example 2

[0029] This embodiment provides a multi-stage Stirling hybrid structure refrigerator with a low-temperature ejector and a room-temperature ejector coupled and phase-adjusted. The difference from Embodiment 1 is that the low-temperature piston 19 is a stepped structure, the low-temperature ejector assembly 9 is used to adjust the phase distribution in the secondary regenerator 4 and the tertiary regenerator 6, and the room-temperature ejector assembly only adjusts the phase distribution in the primary regenerator 2.

[0030] The multi-stage Stirling type hybrid structure refrigerator comprises a refrigerator cold finger, a linear compressor, a room temperature discharger assembly and a low temperature discharger assembly 9; the refrigerator cold finger is a three-stage structure, comprising a main room temperature heat exchanger 1, a primary heat exchanger 2, a primary cold end heat exchanger 3, a primary pulse tube 11, a secondary heat exchanger 4, a secondary cold end heat exchanger 5, a secondary pulse tube 10, a tertiary heat exchanger 6, a tertiary cold end heat exchanger 7 and a tertiary pulse tube 8; the linear compressor comprises a compressor housing 24 and a compression piston 12 disposed in the compressor housing 24, and the cavity between the compressor housing 24 and the compression piston 12 is a room temperature compression cavity; the room temperature discharge The low-temperature discharger assembly includes a room-temperature cylinder wall 13, a room-temperature piston 14 and a room-temperature supporting leaf spring 15; the low-temperature discharger assembly 9 includes a low-temperature cylinder wall 20, a low-temperature piston 19 and a low-temperature supporting leaf spring 21; the room-temperature compression chamber is connected to the main room-temperature heat exchanger 1; the main room-temperature heat exchanger 1, the first-stage heat exchanger 2 and the first-stage cold-end heat exchanger 3 are connected in sequence, the first-stage cold-end heat exchanger 3 is respectively connected to the channel of the low-temperature cylinder wall 20 and the first-stage pulse tube 11, the channel of the low-temperature cylinder wall 20 is connected to the second-stage heat exchanger 4, the second-stage heat exchanger 4 is connected to the second-stage cold-end heat exchanger 5, the second-stage cold-end heat exchanger 5 is respectively connected to the second-stage pulse tube 10 and the third-stage heat exchanger 6 is connected, the three-stage regenerator 6, the three-stage cold end heat exchanger 7, and the three-stage pulse tube 8 are connected in sequence; the outer side of the room temperature support leaf spring 15 is fixedly connected to the inner wall of the room temperature cylinder wall 13, and the inner side is fixedly supported by the room temperature piston 14; the end faces of the room temperature piston 14 on both sides are the first-stage expansion piston end 17 and the room temperature compression piston end 18 respectively, the first-stage expansion piston end 17 is connected to the first-stage pulse tube 11 through the channel of the room temperature cylinder wall 13, the cavity between the first-stage expansion piston end 17 and the first-stage pulse tube 11 is the first-stage expansion cavity, and the room temperature compression piston end 18 is connected to the room temperature compression cavity; the outer side of the low temperature support leaf spring 21 is connected to the low temperature cylinder wall 2 0 is fixedly connected to the inner wall of the cryogenic cylinder wall 20, and the inner side is fixedly supported by the cryogenic piston 19; the cryogenic piston 19 is a stepped structure, and the end faces on both sides are respectively the third-stage expansion piston end 22 and the cryogenic compression piston end 23, and the annular surface located between the end faces on both sides is the second-stage expansion piston end 16, the third-stage expansion piston end 22 is located in the third-stage pulse tube 8, the second-stage expansion piston end 16 is connected with the second-stage pulse tube 10 through the channel of the cryogenic cylinder wall 20, the cavity between the second-stage expansion piston end 16 and the second-stage pulse tube 10 is the second-stage expansion cavity, and the cavity between the cryogenic compression piston end 23, the cryogenic cylinder wall 20 and the first-stage cold end heat exchanger 3 is the cryogenic compression cavity.

[0031] In the above-mentioned multi-stage Stirling type hybrid structure refrigerator, the cold fingers of the refrigerator are of a fully coaxial structure; the secondary pulse tube 10 is of an annular structure, and is located between the secondary regenerator 4 and the tertiary pulse tube 11 .

[0032] In the above-mentioned multi-stage Stirling type hybrid structure refrigerator, gap sealing is adopted between the low-temperature piston 19 and the low-temperature cylinder wall 20, and between the room-temperature piston 14 and the room-temperature cylinder wall 13.

[0033] Working principle: The compression piston 12 of the linear compressor reciprocates, and the working medium helium forms periodic pressure fluctuations in the system. The working medium passes through the room temperature compression chamber, the main room temperature heat exchanger 1, the first stage regenerator 2, and the first stage cold end heat exchanger 3, and the temperature gradually decreases. A diversion occurs at the first stage cold end heat exchanger 3, and a part of it enters the first stage expansion chamber formed by the first stage pulse tube 11, channel I and the first stage expansion piston end 17 of the room temperature ejector assembly, and the rest enters the second stage regenerator 4 and the second stage cold end heat exchanger 5, and the temperature decreases again. A part of it enters the second stage expansion chamber formed by the second stage pulse tube 10 and the second stage expansion piston end 16 of the low temperature ejector assembly 9, and the rest enters the third stage regenerator 6 and the third stage cold end heat exchanger 7, and the temperature drops to a deep low temperature, and then enters between the third stage pulse tube 8 and the third stage expansion piston end 22 of the low temperature ejector assembly 9. The working fluid helium flows in an alternating manner in the system, and the room temperature ejector assembly and the low temperature ejector assembly 9 serve as phase adjustment mechanisms to adjust the phase difference between the pressure wave and the mass flow in the system.

[0034] The low temperature displacer assembly 9 adjusts the phase distribution in the secondary regenerator 4 and the tertiary regenerator 6 by relying on the stiffness of the low temperature support leaf spring 21, the dynamic mass of the low temperature piston 19, the mechanical damping, the area difference between the secondary expansion piston end 16 and the tertiary expansion piston end 22, and the pressure difference between the secondary regenerator 4 and the tertiary regenerator 6. The room temperature displacer assembly adjusts the phase distribution in the primary regenerator 2 by relying on the stiffness of the room temperature support leaf spring 15, the dynamic mass of the room temperature piston 15, the mechanical damping, and the pressure difference between the primary regenerator 2, and recovers the expansion acoustic work at the end of the primary pulse tube 11 to the compression chamber. The whole system realizes high efficiency and long life operation in the deep low temperature zone.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-stage Stirling type hybrid structure refrigerator with low temperature ejector and room temperature ejector coupled and phase-adjusted, characterized in that: It includes a refrigerator cold finger, a linear compressor, a room temperature ejector assembly and a low temperature ejector assembly (9); The cold finger of the refrigerator is a three-stage structure, comprising a main room temperature heat exchanger (1), a first-stage heat regenerator (2), a first-stage cold end heat exchanger (3), a first-stage pulse tube (11), a second-stage heat regenerator (4), a second-stage cold end heat exchanger (5), a second-stage pulse tube (10), a third-stage heat regenerator (6), a third-stage cold end heat exchanger (7) and a third-stage pulse tube (8); The linear compressor comprises a compressor housing (24) and a compression piston (12) disposed in the compressor housing (24); the cavity between the compressor housing (24) and the compression piston (12) is a room temperature compression cavity; The room temperature ejector assembly comprises a room temperature cylinder wall (13), a room temperature piston (14) and a room temperature supporting leaf spring (15); The low-temperature ejector assembly (9) comprises a low-temperature cylinder wall (20), a low-temperature piston (19) and a low-temperature supporting leaf spring (21); The room temperature compression chamber is in communication with the main room temperature heat exchanger (1); The main room temperature heat exchanger (1), the first-stage heat regenerator (2) and the first-stage cold end heat exchanger (3) are connected in sequence; the first-stage cold end heat exchanger (3) is connected to the first-stage pulse tube (11) and the second-stage heat regenerator (4) respectively; the second-stage heat regenerator (4) is connected to the second-stage cold end heat exchanger (5); the second-stage cold end heat exchanger (5) is connected to the channel of the low-temperature cylinder wall (20) and the second-stage pulse tube (10) respectively; the channel of the low-temperature cylinder wall (20) is connected to the third-stage heat regenerator (6); the third-stage heat regenerator (6), the third-stage cold end heat exchanger (7) and the third-stage pulse tube (8) are connected in sequence; The outer side of the room temperature supporting leaf spring (15) is fixedly connected to the inner wall of the room temperature cylinder wall (13), and the inner side fixedly supports the room temperature piston (14); The room temperature piston (14) is a stepped structure, and the end faces on both sides are respectively a secondary expansion piston end (16) and a room temperature compression piston end (18), and the annular surface between the end faces on both sides is a primary expansion piston end (17), the primary expansion piston end (17) is connected to the primary pulse tube (11) through a channel of the room temperature cylinder wall (13), the cavity between the primary expansion piston end (17) and the primary pulse tube (11) is a primary expansion cavity, the secondary expansion piston end (16) is connected to the secondary pulse tube (10) through a channel of the room temperature cylinder wall (13), the cavity between the secondary expansion piston end (16) and the secondary pulse tube (10) is a secondary expansion cavity, and the room temperature compression piston end (18) is connected to the room temperature compression cavity; The outer side of the low-temperature support leaf spring (21) is fixedly connected to the inner wall of the low-temperature cylinder wall (20), and the inner side fixedly supports the low-temperature piston (19); The end surfaces on both sides of the low-temperature piston (19) are respectively a third-stage expansion piston end (22) and a low-temperature compression piston end (23); the third-stage expansion piston end (22) is located in the third-stage pulse tube (8); and the cavity between the low-temperature compression piston end (23), the low-temperature cylinder wall (20) and the second-stage cold end heat exchanger (5) is a low-temperature compression cavity; The low-temperature ejector assembly (9) adjusts the sound field distribution in the three-stage regenerator (6) by relying on the stiffness of the low-temperature support leaf spring (21), the dynamic mass of the low-temperature piston (19), mechanical damping, and the pressure difference on both sides of the three-stage regenerator (6); The room temperature ejector assembly adjusts the sound field distribution inside the primary regenerator (2) and the secondary regenerator (4) by relying on the stiffness of the room temperature supporting leaf spring (15), the dynamic mass of the room temperature piston (14), the mechanical damping, the area difference between the primary expansion piston end (17) and the secondary expansion piston end (16), and the pressure difference between the primary regenerator (2) and the secondary regenerator (4), and recovers the expansion sound work at the same time.

2. The multi-stage Stirling hybrid structure refrigerator with low-temperature ejector and room-temperature ejector coupled and phase-adjusted according to claim 1, characterized in that: The cold finger of the refrigerator is a fully coaxial structure; The primary pulse tube (11) is an annular structure and is located between the primary regenerator (2) and the secondary pulse tube (10).

3. The multi-stage Stirling hybrid structure refrigerator with low-temperature ejector and room-temperature ejector coupled and phase-adjusted according to claim 1 or 2, characterized in that: Gap sealing is adopted between the low-temperature piston (19) and the low-temperature cylinder wall (20), and between the room-temperature piston (14) and the room-temperature cylinder wall (13).

4. A multi-stage Stirling type hybrid structure refrigerator with a low temperature ejector and a room temperature ejector coupled and phase-adjusted, characterized in that: It includes a refrigerator cold finger, a linear compressor, a room temperature ejector assembly and a low temperature ejector assembly (9); The cold finger of the refrigerator is a three-stage structure, comprising a main room temperature heat exchanger (1), a first-stage heat regenerator (2), a first-stage cold end heat exchanger (3), a first-stage pulse tube (11), a second-stage heat regenerator (4), a second-stage cold end heat exchanger (5), a second-stage pulse tube (10), a third-stage heat regenerator (6), a third-stage cold end heat exchanger (7) and a third-stage pulse tube (8); The linear compressor comprises a compressor housing (24) and a compression piston (12) disposed in the compressor housing (24); the cavity between the compressor housing (24) and the compression piston (12) is a room temperature compression cavity; The room temperature ejector assembly comprises a room temperature cylinder wall (13), a room temperature piston (14) and a room temperature supporting leaf spring (15); The low-temperature ejector assembly (9) comprises a low-temperature cylinder wall (20), a low-temperature piston (19) and a low-temperature supporting leaf spring (21); The room temperature compression chamber is in communication with the main room temperature heat exchanger (1); The main room temperature heat exchanger (1), the first-stage heat regenerator (2) and the first-stage cold end heat exchanger (3) are connected in sequence; the first-stage cold end heat exchanger (3) is respectively connected to the channel of the low-temperature cylinder wall (20) and the first-stage pulse tube (11); the channel of the low-temperature cylinder wall (20) is connected to the second-stage heat regenerator (4); the second-stage heat regenerator (4) is connected to the second-stage cold end heat exchanger (5); the second-stage cold end heat exchanger (5) is respectively connected to the second-stage pulse tube (10) and the third-stage heat regenerator (6); the third-stage heat regenerator (6), the third-stage cold end heat exchanger (7) and the third-stage pulse tube (8) are connected in sequence; The outer side of the room temperature supporting leaf spring (15) is fixedly connected to the inner wall of the room temperature cylinder wall (13), and the inner side fixedly supports the room temperature piston (14); The end surfaces on both sides of the room temperature piston (14) are respectively a primary expansion piston end (17) and a room temperature compression piston end (18); the primary expansion piston end (17) is connected to the primary pulse tube (11) through a channel of the room temperature cylinder wall (13); the cavity between the primary expansion piston end (17) and the primary pulse tube (11) is a primary expansion cavity; and the room temperature compression piston end (18) is connected to the room temperature compression cavity; The outer side of the low-temperature support leaf spring (21) is fixedly connected to the inner wall of the low-temperature cylinder wall (20), and the inner side fixedly supports the low-temperature piston (19); The low-temperature piston (19) is a stepped structure, and the end faces on both sides are respectively a third-stage expansion piston end (22) and a low-temperature compression piston end (23); the annular surface located between the end faces on both sides is a second-stage expansion piston end (16); the third-stage expansion piston end (22) is located in the third-stage pulse tube (8); the second-stage expansion piston end (16) is connected to the second-stage pulse tube (10) through a channel of the low-temperature cylinder wall (20); the cavity between the second-stage expansion piston end (16) and the second-stage pulse tube (10) is a second-stage expansion cavity; and the cavity between the low-temperature compression piston end (23), the low-temperature cylinder wall (20) and the first-stage cold end heat exchanger (3) is a low-temperature compression cavity; The low-temperature ejector assembly (9) adjusts the sound field distribution in the secondary heat regenerator (4) and the tertiary heat regenerator (6) by relying on the stiffness of the low-temperature support leaf spring (21), the dynamic mass of the low-temperature piston (19), the mechanical damping, the area difference between the secondary expansion piston end (16) and the tertiary expansion piston end (22), and the pressure difference between the two sides of the secondary heat regenerator (4) and the tertiary heat regenerator (6); The room temperature ejector assembly adjusts the sound field distribution in the primary regenerator (2) by relying on the stiffness of the room temperature supporting leaf spring (15), the dynamic mass of the room temperature piston (14), mechanical damping and the pressure difference on both sides of the primary regenerator (2), while recovering the expansion sound work.

5. The multi-stage Stirling hybrid structure refrigerator with low-temperature ejector and room-temperature ejector coupled and phase-adjusted according to claim 4, characterized in that: The cold finger of the refrigerator is a fully coaxial structure; The secondary pulse tube (10) is an annular structure and is located between the secondary regenerator (4) and the tertiary pulse tube (8).

6. The multi-stage Stirling hybrid structure refrigerator with low-temperature ejector and room-temperature ejector coupled and phase-adjusted according to claim 4 or 5, characterized in that: Gap sealing is adopted between the low-temperature piston (19) and the low-temperature cylinder wall (20), and between the room-temperature piston (14) and the room-temperature cylinder wall (13).

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