An integrated coaxial pulse tube cryocooler

Abstract

The application discloses an integrated coaxial pulse tube refrigerator and belongs to the technical field of pulse tube refrigerators, comprising a refrigerator cold finger, a driving mechanism and a piston phase modulation mechanism; the refrigerator cold finger comprises a pulse tube, a regenerator, a cold end heat exchanger and a hot end heat exchanger; the driving mechanism comprises a mounting shell, a driving cylinder body, a driving component and a driving piston body coaxial with the pulse tube, the driving piston body separates a piston cavity into a working chamber and a back pressure chamber, and the working chamber is communicated with the hot end of the regenerator through a gas inlet pipeline; the piston phase modulation mechanism comprises a phase modulation cylinder body, an elastic support component and a phase modulation piston body coaxial with the driving piston body, the phase modulation piston body separates a phase modulation cavity into an expansion chamber and a recovery chamber, the expansion chamber is communicated with the open end of the pulse tube through a phase modulation pipeline, and the recovery chamber is communicated with the back pressure chamber. The coaxial arrangement of the mechanisms is simple and compact, the loss of the connecting pipeline is small, the integration, compactness and high efficiency of the refrigerator are realized, and the application is the innovation target of the low-temperature refrigerator.

Description

Technical Field

[0001] This invention relates to the field of pulse tube refrigerator technology, and in particular to an integrated coaxial pulse tube refrigerator. Background Technology

[0002] Pulse tube refrigerators are an important branch of the field of regenerative small-scale cryogenic refrigerators. They mainly include the cold finger, main drive mechanism, and phase adjustment mechanism. The phase adjustment mechanism is used to adjust the phase relationship between the mass flow and pressure wave of the working fluid within the pulse tube refrigerator. Phase adjustment mechanisms include orifice-gas-sump type, bidirectional air-inlet type, inertial tube type, and piston type. Piston-type phase adjustment mechanisms are widely used due to their wide phase adjustment range and precise phase adjustment angle. Piston-type phase adjustment mechanisms are further divided into active piston phase adjustment and pneumatic piston phase adjustment based on the driving method. However, existing pulse tube refrigerators generally have a problem: the main drive mechanism, cold finger, and phase adjustment mechanism are often arranged independently, as seen in patents "202110392489.1" ("A Single-Piston Phase Adjustment Pulse Tube Refrigerator System and Its Vibration Reduction Method") and "202120742047.0" ("Coaxial Active Phase Adjustment Power Recovery Pulse Tube Refrigerator"). The independent arrangement of the components makes the pulse tube refrigerator complex in structure, cumbersome in installation, and results in large losses in the connecting pipelines, making it difficult for engineering applications with requirements such as compact structure and high power consumption. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned technical problems and provide an integrated coaxial pulse tube refrigerator. The various mechanisms are arranged coaxially, the whole machine is simple and compact, and the connection pipeline loss is small. The integration, compactness and high efficiency of the refrigerator are the goals of the innovation of cryogenic refrigerators, which is convenient for coupling with the cooled device.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention discloses an integrated coaxial pulse tube refrigerator, including a refrigerator cooling finger, an active drive mechanism, and a piston-type phase adjustment mechanism;

[0005] The refrigeration unit includes a pulse tube, a regenerator, a cold end heat exchanger, and a hot end heat exchanger. The inner wall of the regenerator and the outer wall of the pulse tube are coaxially arranged. The cold end heat exchanger is connected to the closed end of the pulse tube and the cold end of the regenerator for heat exchange. The hot end heat exchanger is connected to the open end of the pulse tube and the hot end of the regenerator for heat exchange.

[0006] The active drive mechanism includes a mounting housing and a drive cylinder body with a piston cavity inside. The mounting housing includes a drive mounting end and a phase-adjusting mounting end. The drive mounting end is fixedly connected to the hot end heat exchanger. The drive cylinder body is disposed inside the drive mounting end. The piston cavity is provided with a drive piston body and a drive component that drives the drive piston body to reciprocate along its axis. The axis of the drive piston body is coaxial with the axis of the pulse tube. The drive piston body divides the piston cavity into a working chamber and a back pressure chamber along its axial direction. The working chamber is connected to the hot end of the regenerator through an air inlet pipe.

[0007] The piston-type phase-adjusting mechanism includes a phase-adjusting cylinder body disposed within the phase-adjusting mounting end. The phase-adjusting cylinder body is provided with a phase-adjusting cavity. The phase-adjusting cavity is provided with a phase-adjusting piston body and an elastic support member for resetting the phase-adjusting piston body. The axis of the phase-adjusting piston body is coaxial with the axis of the driving piston body. The phase-adjusting piston body divides the phase-adjusting cavity into an expansion chamber and a recovery chamber. The expansion chamber is connected to the open end of the pulse tube through a phase-adjusting pipeline, and the recovery chamber is connected to the back pressure chamber.

[0008] Preferably, the driving component is a linear motor or a thermoacoustic motor.

[0009] Preferably, the elastic support member is a leaf spring or a helical support spring connected to the piston rod of the phase-adjusting piston body.

[0010] Preferably, a moving component for driving the phase-adjusting piston body to reciprocate along its axis is provided between the elastic support member and the phase-adjusting piston body.

[0011] Preferably, the moving component is a linear motor or a thermoacoustic motor.

[0012] Preferably, it includes a vibration damping mechanism installed at the phase-adjusting mounting end of the mounting housing.

[0013] Preferably, the vibration damping mechanism includes a balancing mass block and a connecting rod fixedly connected to the phase adjustment mounting end. The balancing mass block is connected to both sides of the connecting rod through an elastic vibration damping component, and the axis of the connecting rod is coaxial with the axis of the phase adjustment piston body.

[0014] Preferably, the vibration damping mechanism includes a vibration damping cylinder body fixedly connected to the phase adjustment mounting end. The vibration damping cylinder body is provided with a vibration damping piston body and an elastic vibration damping member supporting the vibration damping piston body. The axis of the vibration damping piston body is coaxial with the axis of the phase adjustment piston body. A motion member for driving the vibration damping piston body to reciprocate along its axis is provided between the elastic vibration damping member and the phase adjustment piston body. The motion direction of the vibration damping piston body is opposite to the combined motion direction of the phase adjustment piston body and the driving piston body.

[0015] Preferably, the elastic damping component is a leaf spring or a helical support spring.

[0016] Preferably, the moving component is a linear motor or a thermoacoustic motor.

[0017] The present invention achieves the following technical effects compared to the prior art:

[0018] 1. In this integrated coaxial pulse tube refrigerator, the pulse tube refrigerator's cooling finger, active drive mechanism, and piston-type phase adjustment mechanism are arranged coaxially. The whole machine is simple and compact, with low connection pipeline losses. The integration, compactness, and high efficiency of the refrigerator are the goals of low-temperature refrigerator innovation. It is convenient to couple with the cooled device. The phase adjustment mechanism adopts a piston-type phase adjustment mechanism, which has a wide phase adjustment range, compact structure, and precise phase adjustment angle. This is conducive to achieving high efficiency of the pulse tube refrigerator, thereby meeting the requirements of compact structure and high power consumption in engineering applications.

[0019] 2. In this integrated coaxial pulse tube refrigerator, a vibration damping mechanism has been added, which can reduce the cold finger vibration output of the pulse tube refrigerator, making this integrated coaxial pulse tube refrigerator applicable to sensitive devices such as infrared detectors.

[0020] 3. In this integrated coaxial pulse tube refrigerator, the vibration damping mechanism is also coaxially arranged with the pulse tube refrigerator's cooling finger, active drive mechanism, and piston-type phase adjustment mechanism. On the one hand, this ensures that the integrated coaxial pulse tube refrigerator has a compact structure, and on the other hand, the coaxial arrangement is conducive to vibration suppression. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the internal structure of an integrated coaxial pulse tube refrigerator (with a passive piston-type phase adjustment mechanism and a passive vibration damping mechanism);

[0023] Figure 2 This is a schematic diagram of the internal structure of an integrated coaxial pulse tube refrigerator (with an active piston phase adjustment mechanism and a passive vibration damping mechanism);

[0024] Figure 3 This is a schematic diagram of the internal structure of an integrated coaxial pulse tube refrigerator (with an active piston phase adjustment mechanism and an active damping mechanism).

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Refrigeration unit cooling index; 2. Active drive mechanism; 3. Piston-type phase adjustment mechanism; 4. Vibration damping mechanism; 5. Inlet pipe; 6. Phase adjustment pipe; 7. Mounting housing;

[0027] 101. Pulse tube; 102. Regenerator; 103. Cold end heat exchanger; 104. Hot end heat exchanger;

[0028] 201. Drive cylinder body; 202. Drive piston body; 203. Working chamber; 204. Back pressure chamber; 205. Drive component;

[0029] 301. Phase-adjusting cylinder body; 302. Phase-adjusting piston body; 303. Expansion chamber; 304. Recovery chamber; 305. Elastic support component; 306. Moving component;

[0030] 401. Balancing mass block; 402. Connecting rod; 403. Elastic damping component; 404. Damping cylinder body; 405. Damping piston body; 406. Moving component. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] This embodiment provides an integrated coaxial pulse tube refrigerator, such as Figures 1 to 3 As shown, it includes a refrigeration unit (cooling index 1), an active drive mechanism (2), and a piston-type phase adjustment mechanism (3). Wherein:

[0033] The refrigeration unit 1 includes a pulse tube 101, a regenerator 102, a cold-end heat exchanger 103, and a hot-end heat exchanger 104. The inner wall of the regenerator 102 and the outer wall of the pulse tube 101 are coaxially aligned, allowing the working fluid in the regenerator 102 to flow into the pulse tube 101. The cold-end heat exchanger 103 is fixedly connected to the closed end of the pulse tube 101 and allows for heat exchange, and is also fixedly connected to the cold end of the regenerator 102 and allows for heat exchange. The hot-end heat exchanger 104 is fixedly connected to the open end of the pulse tube 101 and allows for heat exchange, and is also fixedly connected to the hot end of the regenerator 102 and allows for heat exchange.

[0034] The active drive mechanism 2 includes a mounting housing 7 and a drive cylinder body 201. The mounting housing 7 includes a drive mounting end and a phase-adjusting mounting end, with the drive mounting end fixedly connected to the hot-end heat exchanger 104. The drive cylinder body 201 is installed inside the drive mounting end and has a piston cavity. Within the piston cavity, a drive piston body 202 and a drive component 205 are located. The axis of the drive piston body 202 is coaxial with the axis of the pulse tube 101, and a micron-level gap seal is formed between the drive piston body 202 and the piston cavity. The drive piston body 202 divides the piston cavity into a working chamber 203 and a back pressure chamber 204, with the working chamber 203 located near the hot-end heat exchanger 104. Driven by the drive component 205, the drive piston body 202 can reciprocate along its axis within the piston cavity, thereby continuously changing the spatial size of the working chamber 203 and the back pressure chamber 204. The working chamber 203 is connected to the hot end of the regenerator 102 through the air inlet pipe 5, so that the working fluid is alternately pressed into and extracted from the regenerator 102 under the reciprocating motion of the driving piston body 202, thereby realizing the alternating pressing into and extraction from the pulse tube 101.

[0035] The piston-type phase-adjusting mechanism 3 includes a phase-adjusting cylinder body 301, which is installed in the phase-adjusting mounting end of the mounting housing 7. The phase-adjusting cylinder body 301 has a phase-adjusting cavity, within which a phase-adjusting piston body 302 and an elastic support member 305 are located. The axis of the phase-adjusting piston body 302 is coaxial with the axis of the driving piston body 202, and a micron-level gap seal is formed between the phase-adjusting piston body 302 and the phase-adjusting cavity. The phase-adjusting piston body 302 divides the phase-adjusting cavity into an expansion chamber 303 and a recovery chamber 304 along its axial direction. The expansion chamber 303 is connected to the open end of the pulse tube 101 via a phase-adjusting pipe 6, and the recovery chamber 304 is connected to the back pressure chamber 204, enabling the coordinated operation of the phase-adjusting piston body 302 and the driving piston body 202. The expansion chamber 303 is located away from the back pressure chamber 204. The elastic support component 305 provides elastic restoring force to the phase-adjusting piston 302, allowing it to self-recover. Combined with the alternating entry and exit of gas through the phase-adjusting pipeline 6, the phase-adjusting piston 302 can reciprocate within the phase-adjusting cavity, thereby adjusting the phase relationship between the mass flow and pressure wave of the working fluid within the pulse tube refrigerator. This piston-type phase-adjusting mechanism 3 is a passive adjustment method.

[0036] Working principle:

[0037] Driven by the driving component 205, the piston body 202 reciprocates continuously within the piston cavity, causing the working chamber 203 to alternately compress and expand. The working fluid alternately enters and exits the regenerator 102 through the intake pipe 5. The working fluid entering the regenerator 102 then alternately enters and exits the pulse tube 101. The working fluid then alternately enters and exits the expansion chamber 303 through the phase-adjusting pipe 6. With the help of the elastic support component 305, the phase-adjusting piston body 302 reciprocates continuously within the phase-adjusting cavity, thereby adjusting the phase relationship between the mass flow of the working fluid and the pressure wave. The cold and heat are drawn out through the cold end heat exchanger 103 and the hot end heat exchanger 104, respectively.

[0038] This integrated coaxial pulse tube refrigeration unit features a coaxial arrangement of the refrigeration unit 1, the active drive mechanism 2, and the piston-type phase adjustment mechanism 3. Its simple structure and low connection pipeline losses achieve integration, compactness, and high efficiency, meeting the innovation goals of cryogenic refrigeration units and satisfying engineering applications with high requirements for compact structure and power consumption.

[0039] In this embodiment, as Figures 1 to 3 As shown, the driving component 205 is a linear motor or a thermoacoustic engine. The mover of the linear motor is fixedly connected to the piston rod of the driving piston body 202 to drive the driving piston body 202 to reciprocate along the axis. The thermoacoustic engine, also known as a thermoacoustic actuator, thermoacoustic motor, or thermoacoustic compressor, is a new type of machine that converts thermal energy into mechanical energy. It is a new type of compressor without moving mechanical parts, using sound waves to oscillate gas to drive the driving piston body 202. Of course, the driving component 205 can also adopt other driving methods, such as an electric telescopic rod, which is fixedly connected to the driving piston body 202 to reciprocate and push the driving piston body 202. The piston rod of the driving piston body 202 can have a supporting guide component to ensure the accuracy of the linear motion of the driving piston body 202. Alternatively, the supporting guide component can be omitted, and the driving characteristics of the active driving mechanism 2 can be used to provide restoring force, thereby reducing the number of support mechanisms in the whole machine and contributing to the overall weight reduction.

[0040] In this embodiment, as Figures 1 to 3 As shown, the elastic support member 305 is a leaf spring or a helical support spring, which is connected to the piston rod of the phase-adjusting piston body 302. When the phase-adjusting piston body 302 and the drive piston body 202 are installed, the piston rods of the phase-adjusting piston body 302 and the drive piston body 202 can be oriented towards each other.

[0041] To achieve active adjustment of the piston-type phase-adjusting mechanism 3, in this embodiment, as follows: Figures 1 to 3As shown, a moving member 306 is provided between the elastic support member 305 and the phase-adjusting piston body 302. The moving member 306 is used to drive the phase-adjusting piston body 302 to reciprocate along its axis, thereby making the piston-type phase-adjusting mechanism 3 an actively adjusting mechanism.

[0042] Furthermore, in this embodiment, as Figures 1 to 3 As shown, the moving component 306 is a linear motor or a thermoacoustic machine. The mover of the linear motor is fixedly connected to the piston rod of the phase-adjusting piston body 302, thereby driving the phase-adjusting piston body 302 to reciprocate along the axis. The thermoacoustic machine uses sound waves to oscillate gas, thereby driving the phase-adjusting piston body 302 to reciprocate. Of course, the moving component 306 can also adopt other driving methods, such as an electric telescopic rod, which is fixedly connected to the phase-adjusting piston body 302 to reciprocate and push the phase-adjusting piston body 302.

[0043] Because the cooling of sensitive devices such as infrared detectors, cryogenic electronic devices, and superconducting technologies is highly sensitive to the vibration of cryogenic refrigerators, significant vibration can severely affect detection performance and even damage the devices themselves. Therefore, in order to reduce the vibration of the integrated coaxial pulse tube refrigerator, in this embodiment, such as... Figures 1 to 3 As shown, this integrated coaxial pulse tube refrigerator also includes a vibration damping mechanism 4, which is installed on the phase-adjusting mounting end of the mounting housing 7. The vibration damping mechanism 4 can effectively reduce the vibration level of the integrated coaxial pulse tube refrigerator, thereby meeting the cooling requirements of sensitive devices.

[0044] In this embodiment, as Figures 1 to 3 As shown, a passive vibration damping mechanism 4 is proposed. This vibration damping mechanism 4 includes a balancing mass block 401 and a connecting rod 402. The end of the connecting rod 402 is fixedly connected to the phase-adjusting mounting end of the mounting housing 7, and the axis of the connecting rod 402 is coaxially arranged with the axis of the phase-adjusting piston body 302. This coaxial arrangement facilitates vibration suppression. The balancing mass block 401 is connected to both sides of the connecting rod 402 via elastic damping components 403. When the driving piston body 202 and the phase-adjusting piston body 302 vibrate, the balancing mass block 401 and the elastic damping components 403 constitute an elastic vibration damping device. Its vibration damping principle can be referenced from the principle of vibration elimination by elastic dampers.

[0045] In this embodiment, as Figures 1 to 3As shown, an active vibration damping mechanism 4 is proposed. This vibration damping mechanism 4 includes a damping cylinder body 404, which is fixedly connected to the phase-adjusting mounting end of the mounting housing 7. The damping cylinder body 404 contains a damping piston body 405 and an elastic damping member 403. The damping piston body 405 is connected within the damping cylinder body 404 via the elastic damping member 403, which provides elastic reset capability. The axis of the damping piston body 405 is coaxially arranged with the axis of the phase-adjusting piston body 302, which facilitates vibration suppression. A moving member 406 is provided between the elastic damping member 403 and the phase-adjusting piston body 302. The moving member 406 drives the damping piston body 405 to reciprocate along its axis. The direction of movement of the damping piston body 405 is opposite to the combined direction of movement of the phase-adjusting piston body 302 and the driving piston body 202, thereby achieving vibration damping.

[0046] In this embodiment, as Figures 1 to 3 As shown, the elastic damping component 403 is a leaf spring or a helical support spring. When the damping mechanism 4 is a passive mechanism, both ends of the balance mass block 401 are connected to the connecting rod 402 through leaf springs or helical support springs. When the damping mechanism 4 is an active mechanism, the leaf spring or helical support spring is fixedly connected to the piston rod of the damping piston body 405 and the damping cylinder body 404.

[0047] In this embodiment, as Figures 1 to 3 As shown, the moving component 406 is a linear motor or a thermoacoustic motor.

[0048] In this embodiment, as Figures 1 to 3 As shown, the internal packing of the regenerator 102 is stainless steel mesh, holmium copper particles, or erbium trinickel particles.

[0049] In this embodiment, as Figures 1 to 3 As shown, the cold-end heat exchanger 103 and the hot-end heat exchanger 104 are slotted, wire mesh, finned or tube bundle type.

[0050] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An integrated coaxial pulse tube refrigerator, characterized by, The refrigeration machine cold finger comprises a pulse tube, a regenerator, a cold end heat exchanger and a hot end heat exchanger, the inner wall of the regenerator and the outer wall of the pulse tube are coaxially arranged, the cold end heat exchanger is in heat exchange connection with the closed end of the pulse tube and the cold end of the regenerator, and the hot end heat exchanger is in heat exchange connection with the open end of the pulse tube and the hot end of the regenerator. The active driving mechanism comprises a driving cylinder body provided with a piston cavity and a mounting shell, the mounting shell comprises a driving mounting end and a phase modulation mounting end, the driving mounting end is fixedly connected with the hot end heat exchanger, the driving cylinder body is arranged in the interior of the driving mounting end, the piston cavity is provided with a driving piston body and a driving member for driving the driving piston body to reciprocate along the axis thereof, the axis of the driving piston body is coaxial with the axis of the pulse tube, the driving piston body divides the piston cavity into a working cavity and a back pressure cavity along the axial direction thereof, and the working cavity is in communication with the hot end of the regenerator through a gas inlet pipeline. The phase modulation mechanism comprises a phase modulation cylinder body arranged in the phase modulation mounting end, the phase modulation cylinder body is provided with a phase modulation cavity, the phase modulation cavity is provided with a phase modulation piston body and an elastic supporting member for resetting the phase modulation piston body, the axis of the phase modulation piston body is coaxial with the axis of the driving piston body, the phase modulation piston body divides the phase modulation cavity into an expansion cavity and a recovery cavity, the expansion cavity is in communication with the open end of the pulse tube through a phase modulation pipeline, and the recovery cavity is in communication with the back pressure cavity. The driving piston body reciprocates in the piston cavity, so that the working cavity is alternately compressed and expanded, the working medium is alternately introduced into and extracted from the regenerator through the gas inlet pipeline, the working medium introduced into the regenerator is alternately introduced into and extracted from the pulse tube, and then is alternately introduced into and extracted from the expansion cavity through the phase modulation pipeline. The driving member is a linear motor or a thermoacoustic machine.

2. The integrated coaxial pulse tube refrigerator of claim 1, wherein, The elastic supporting member is a leaf spring or a helical supporting spring connected with the piston rod of the phase modulation piston body.

3. The integrated coaxial pulse tube refrigerator of claim 1, wherein, A moving member is arranged between the elastic supporting member and the phase modulation piston body for driving the phase modulation piston body to reciprocate along the axis thereof.

4. The integrated coaxial pulse tube refrigerator of claim 3, wherein, The moving member is a linear motor or a thermoacoustic machine.

5. The integrated coaxial pulse tube refrigerator of claim 4, wherein, A damping mechanism is arranged in the phase modulation mounting end of the mounting shell.

6. The integrated coaxial pulse tube refrigerator of claim 1, wherein, The damping mechanism comprises a balance mass and a connecting rod fixedly connected with the phase modulation mounting end, the balance mass is connected on both sides of the connecting rod through elastic damping members, and the axis of the connecting rod is coaxial with the axis of the phase modulation piston body.

7. The integrated coaxial pulse tube refrigerator of claim 6, wherein, The damping mechanism comprises a damping cylinder body fixedly connected with the phase modulation mounting end, the damping cylinder body is provided with a damping piston body and an elastic damping member for supporting the damping piston body, the axis of the damping piston body is coaxial with the axis of the phase modulation piston body, a moving member is arranged between the elastic damping member and the phase modulation piston body for driving the damping piston body to reciprocate along the axis thereof, and the moving direction of the damping piston body is opposite to the comprehensive moving direction of the phase modulation piston body and the driving piston body.

8. The integrated coaxial pulse tube refrigerator of claim 6, wherein, The elastic damping member is a leaf spring or a helical supporting spring.

9. The integrated coaxial pulse tube refrigerator according to claim 7 or 8, characterized in that ​ 10. The integrated coaxial pulse tube refrigerator of claim 8, wherein, The moving member is a linear motor or a thermoacoustic machine. The moving member is a linear motor or a thermoacoustic machine.

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