Sleeve type heat regenerator structure of pulse tube refrigerator and cold accumulation filler replacement method of sleeve type heat regenerator structure

Abstract

The invention relates to the technical field of pulse tube refrigerators, and particularly provides a sleeve type heat regenerator structure of a pulse tube refrigerator and a cold accumulation filler replacement method of the sleeve type heat regenerator structure. Wherein the sleeve type heat regenerator structure comprises a first-stage heat regenerator pipe wall, a second-stage heat regenerator pipe wall, a first-stage cold end copper block, a first-stage heat exchanger and a first sleeve structure, and a first mounting cavity penetrating in the axis direction is formed in the first-stage heat regenerator pipe wall; a second mounting cavity is formed in the pipe wall of the second-stage heat regenerator in the axial direction in a penetrating manner; the first-stage cold end copper block is connected with the outer side walls of the adjacent ends of the first-stage heat regenerator pipe wall and the second-stage heat regenerator pipe wall, and a communicating channel communicating with the first mounting cavity and the second mounting cavity is formed in the first-stage cold end copper block. The primary heat exchanger is detachably arranged in the communicating channel; the first sleeve structure is assembled in the first mounting cavity in an interference mode, and a first containing cavity is formed in the first sleeve structure and used for containing the first-stage cold storage filler. The cold accumulation packing of the heat regenerator of the pulse tube refrigerator can be quickly disassembled, assembled and replaced.

Description

Technical Field

[0001] The invention relates to the technical field of pulse tube refrigerators, and in particular to a sleeve-type heat regenerator structure of a pulse tube refrigerator and a method for replacing a cold storage filler thereof. Background Art

[0002] Pulse tube refrigerators have many advantages such as low vibration, high reliability and long life because the cold head has no moving parts. They are gradually replacing GM refrigerators and becoming the most widely used small low-temperature refrigerators. In order to obtain lower refrigeration temperatures, pulse tube refrigerators usually require a multi-stage structure. Currently, commercial liquid helium temperature zone pulse tube refrigerators use a two-stage gas-coupled structure and are widely used in quantum computing, condensed matter physics research and other fields.

[0003] As a key core component of the pulse tube refrigerator, the regenerator not only plays the role of storing cold and recovering heat, but is also an important place for the working gas to convert work into heat. Its quality directly determines the refrigeration performance and service life of the pulse tube refrigerator. In the prior art, after the refrigerator is welded as a whole, the secondary regenerator and the primary regenerator must be filled in turn, and the cold storage filler is directly filled in the wall of the regenerator tube. The secondary regenerator cold storage filler is mainly metal particles of different particle sizes such as Lead, Er3Ni and HoCu2, and the primary regenerator cold storage filler is mainly stainless steel wire mesh and copper mesh of different mesh sizes. After the refrigerator is assembled, it is usually integrated into a low-temperature scientific instrument or a dilution refrigerator to achieve more complex system functions.

[0004] After long-term operation of the refrigerator, the granular cold storage filler is constantly washed by the high and low pressure of the working gas, which is very likely to face the risk of breaking and easily cause the heat regenerator to be blocked. The wire mesh cold storage filler is also susceptible to various contaminations brought by the working gas, thereby reducing the heat recovery efficiency. Or if there are quality problems with the cold storage filler itself, these factors will significantly deteriorate the refrigeration performance of the refrigerator.

[0005] In the prior art, problems with the refrigerator regenerator will directly affect the performance of the refrigerator, and even worse, will directly affect the life of the refrigerator, requiring the entire cold storage filler to be removed and replaced. Most users pay more attention to the refrigeration performance of the second stage during the use of the refrigerator. Usually, the granular cold storage filler in the secondary regenerator is more prone to problems. At this time, it is necessary to first remove the wire mesh cold storage filler in the primary regenerator, then remove the granular cold storage filler in the secondary regenerator, and finally refill the secondary regenerator and the primary regenerator in turn. For low-temperature scientific instruments and dilution refrigerator systems, if there is a problem with the cold storage filler in the regenerator, the entire pulse tube refrigerator needs to be removed from the system first, which often takes a lot of time and effort. Summary of the invention

[0006] The present invention provides a sleeve-type heat regenerator structure of a pulse tube refrigerator and a method for replacing cold storage filler thereof, so as to solve the problem in the prior art that when the cold storage filler needs to be replaced, the refrigerator in the entire system must be dismantled first, and the first-stage heat regenerator and then the cold storage filler in the second-stage heat regenerator must be dismantled in sequence, and this process is complicated and time-consuming, which increases maintenance costs and downtime, and the cold storage filler of the refrigerator regenerator can be quickly disassembled and replaced.

[0007] The present invention provides a shell-and-tube regenerator structure of a pulse tube refrigerator, comprising: A first-stage heat regenerator tube wall, wherein a first installation cavity penetrating along the axial direction is formed in the first-stage heat regenerator tube wall; A secondary heat regenerator tube wall, the secondary heat regenerator tube wall is coaxial with the primary heat regenerator tube wall and spaced apart from each other, and a second installation cavity is provided in the secondary heat regenerator tube wall along the axial direction; A primary cold-end copper block, the primary cold-end copper block is respectively connected to the outer side walls of the primary regenerator tube wall and the secondary regenerator tube wall at adjacent ends, and a connecting passage connecting the first installation cavity and the second installation cavity is provided in the primary cold-end copper block; a primary heat exchanger, the primary heat exchanger being detachably disposed in the communication channel; A first sleeve structure is interference-fitted in the first installation cavity. A first accommodating cavity is formed in the first sleeve structure, and the accommodating cavity is used to place a first-level cold storage filler.

[0008] According to a shell-and-tube regenerator structure of a pulse tube refrigerator provided by the present invention, the first shell-and-tube structure includes a first shell and a room temperature end heat exchanger, a first opening is provided at one end of the first shell away from the secondary regenerator, the first opening is communicated with the first accommodating cavity, and the room temperature end heat exchanger is sealed at the first opening.

[0009] According to a sleeve-type heat regenerator structure of a pulse tube refrigerator provided by the present invention, a first connecting hole is provided on the outer wall of the first sleeve near one end of the first opening, and a second connecting hole is provided on the room temperature end heat exchanger corresponding to the position of the first connecting hole. A fastener passes through the first connecting hole and the second connecting hole to connect and fix the first sleeve to the room temperature end heat exchanger.

[0010] According to a sleeve-type heat regenerator structure of a pulse tube refrigerator provided by the present invention, a threaded hole is provided on the side of the room temperature end heat exchanger away from the first sleeve, and the threaded hole is used to cooperate with bolts to remove the first sleeve structure from the first installation cavity.

[0011] According to a sleeve-type heat regenerator structure of a pulse tube refrigerator provided by the present invention, a cold-end vent hole is provided at the end of the first sleeve close to one end of the first-stage heat exchanger, a hot-end vent hole is provided on the room-temperature end heat exchanger, and both the cold-end vent hole and the hot-end vent hole are connected to the first accommodating cavity.

[0012] According to a sleeve-type heat regenerator structure of a pulse tube refrigerator provided by the present invention, an annular sealing groove is provided on the outer wall of the first sleeve, and the sleeve-type heat regenerator structure of the pulse tube refrigerator includes a sealing member, which is arranged in the sealing groove and abuts between the inner wall surface of the first mounting cavity and the outer side surface of the first sleeve structure.

[0013] According to a sleeve-type regenerator structure of a pulse tube refrigerator provided by the present invention, the first-stage regenerator tube wall, the first-stage cold-end copper block and the second-stage regenerator tube wall are integrally connected and arranged.

[0014] According to a shell-and-tube regenerator structure of a pulse tube refrigerator provided by the present invention, the shell-and-tube regenerator structure of the pulse tube refrigerator also includes a second shell-and-tube structure, the second shell-and-tube structure is interference-fitted in the second installation cavity, the second shell-and-tube structure has a second accommodating cavity and a second opening connected to the second accommodating cavity, the second accommodating cavity is used to place a secondary cold storage filler, and the primary heat exchanger is sealed at the second opening.

[0015] The present invention further provides a method for replacing a cold storage filler of a shell-and-tube regenerator structure of a pulse tube refrigerator according to any one of claims 1 to 8, wherein the method for replacing a cold storage filler comprises the following steps: Use bolts to pull the entire first sleeve structure out of the first installation cavity through the threaded holes; The primary heat exchanger is taken out, and it is determined whether there is a second sleeve structure in the second installation cavity (410); if so, the second sleeve structure is taken out, and then the second storage filler (800) is replaced in the second accommodation cavity of the second sleeve structure; if not, the second storage filler (800) in the second installation cavity (410) is directly dumped out of the refrigerator; After the secondary cold storage filler in the second installation cavity is replaced, install the primary heat exchanger back into the communication channel; The first sleeve structure after replacing the first-level cold storage filler is interference-fitted into the first installation cavity.

[0016] According to a method for replacing a cold storage filler provided by the present invention, after taking out the first sleeve structure, the screw is disassembled, the room temperature end heat exchanger is removed, and the primary cold storage filler in the first accommodating chamber is replaced; The sleeve-type regenerator structure of the pulse tube refrigerator provided by the present invention and the method for replacing the cold storage filler thereof, by adding a first sleeve structure in the tube wall of the first-stage regenerator, when it is necessary to replace the second-stage cold storage filler, the operator only needs to pull out the first sleeve structure from the first installation cavity of the tube wall of the first-stage regenerator, and then take out the first-stage heat exchanger, and then directly pour out the granular cold storage material in the second installation cavity from the refrigerator. This process does not require the removal of the entire refrigerator or the removal of the cold storage fillers of multiple regenerators in sequence, which greatly simplifies the replacement process and realizes the rapid disassembly and replacement of the cold storage filler of the pulse tube refrigerator regenerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a shell-and-tube heat regenerator structure of a pulse tube refrigerator provided by the present invention.

[0019] Figure 2 It is a top view of another embodiment of the shell-and-tube regenerator structure of the pulse tube refrigerator provided by the present invention.

[0020] Reference numerals: 10. The shell and tube regenerator structure of pulse tube refrigerator; 100. primary regenerator tube wall; 110. first installation cavity; 200, primary cold end copper block; 210, connecting channel; 300, primary heat exchanger; 400, secondary regenerator tube wall; 410, second installation cavity; 500, first sleeve structure; 510, first sleeve; 511, first accommodating cavity; 512, first opening; 513, first connecting hole; 514, cold end vent hole; 515, sealing groove; 520, room temperature end heat exchanger; 521, second connecting hole; 522, threaded hole; 523, hot end vent hole; 600, fasteners; 700, primary cold storage filler; 800, secondary cold storage filler; 900, room temperature end stainless steel flange. DETAILED DESCRIPTION

[0021] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0024] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0026] Combine the following Figure 1 to Figure 2 The sleeve-type heat regenerator structure of the pulse tube refrigerator and the method for replacing the cold storage filler thereof provided in the embodiment of the present invention are described in detail through specific embodiments and application scenarios.

[0027] In the embodiment of the present invention, Figure 1 to Figure 2 As shown, the sleeve-type regenerator structure 10 of the pulse tube refrigerator includes a primary regenerator tube wall 100, a secondary regenerator tube wall 400, a primary cold end copper block 200, a primary heat exchanger 300 and a first sleeve structure 500. A first installation cavity 110 is formed in the primary regenerator tube wall 100 and penetrates along the axial direction; the secondary regenerator tube wall 400 is coaxial with the primary regenerator tube wall 100 and is spaced apart from each other, and a second installation cavity 410 is formed in the secondary regenerator tube wall 400 and penetrates along the axial direction; the primary regenerator tube wall 100 is provided with a first installation cavity 410; the primary regenerator tube wall 100 is provided with a second installation cavity 410 ... first installation cavity 410; the primary regenerator tube wall 100 is provided with a first installation cavity 410; the primary regenerator tube wall 100 is provided with a first installation cavity 410; the primary regenerator tube wall 100 is provided with a first installation cavity 410; the primary regenerator tube wall 100 is provided with a first installation cavity 410; the primary regenerator tube wall 100 is provided with a first installation The end copper block 200 is respectively connected to the outer side walls of the adjacent ends of the first-stage heat exchanger tube wall 100 and the second-stage heat exchanger tube wall 400; a connecting channel 210 connecting the first installation cavity 110 and the second installation cavity 410 is provided in the first-stage cold end copper block 200; the first-stage heat exchanger 300 is detachably arranged in the connecting channel 210; the first sleeve structure 500 is interference fitted in the first installation cavity 110, and a first accommodating cavity 511 is formed in the first sleeve structure 500, and the accommodating cavity is used to place the first-stage cold storage filler 700.

[0028] The primary regenerator tube wall 100 is the basic part of the shell-and-tube regenerator structure, which provides a closed space, namely the first installation cavity 110, for installing and fixing the first shell-and-tube structure 500. This installation cavity runs through the entire primary regenerator tube wall 100 along the axial direction, ensuring that the working fluid gas can flow smoothly therein and perform heat exchange with the cold storage filler.

[0029] The secondary regenerator tube wall 400 is coaxial with the primary regenerator tube wall 100 and spaced apart from each other, forming an independent heat exchange area. A second installation cavity 410 also penetrates the secondary regenerator tube wall 400 along the axial direction. The second installation cavity 410 is used to accommodate the secondary cold storage filler 800 or as a secondary heat exchange channel.

[0030] The primary cold end copper block 200 is respectively connected to the outer side walls of the adjacent ends of the primary regenerator tube wall 100 and the secondary regenerator tube wall 400. This connection method not only enhances the overall stability of the refrigerator structure, but also realizes the gas volume distribution of the working medium gas between the two-stage regenerators through the connecting channel 210 in the primary cold end copper block 200 and the primary heat exchanger 300.

[0031] The primary heat exchanger 300 is designed to be detachably disposed in the communication channel 210. The primary heat exchanger 300 is mainly used to further cool the working gas and improve the refrigeration efficiency, and at the same time, it plays a role in allocating the working gas volume of the two-stage regenerator.

[0032] The first sleeve structure 500 is interference-fitted into the first installation cavity 110 of the primary regenerator tube wall 100 to ensure good sealing and thermal isolation. A first accommodating cavity 511 is formed in the sleeve structure for placing the primary cold storage filler 700. The cold storage filler is effectively encapsulated in the sleeve, which facilitates subsequent disassembly, assembly and replacement operations.

[0033] It should be noted that in the present application, the primary cold storage filler 700 is a stainless steel wire mesh and a copper mesh of different mesh sizes, and the secondary cold storage filler 800 is metal particles such as Lead, Er3Ni and HoCu2 of different particle sizes.

[0034] The present application adds a first sleeve structure 500 in the first-stage regenerator tube wall 100. When the first-stage cold storage filler 700 needs to be replaced, the operator only needs to pull out the first sleeve structure 500 from the first installation cavity 110 of the first-stage regenerator tube wall 100, and then take out the first-stage heat exchanger 300, and then directly pour out the granular cold storage material in the second installation cavity 410 from the refrigerator. This process does not require the removal of the entire refrigerator or the removal of the cold storage fillers of multiple regenerators in sequence, which greatly simplifies the replacement process and realizes the rapid disassembly and replacement of the cold storage filler of the pulse tube refrigerator regenerator.

[0035] In one embodiment, the first sleeve 510 is made of non-metallic materials, which can significantly reduce heat leakage between the working gas, the cold storage filler and the regenerator tube wall, thereby improving the heat exchange efficiency. Specifically, the non-metallic materials include polytetrafluoroethylene, epoxy resin, glass fiber reinforced plastics, etc.

[0036] Reference Figure 1 According to a pulse tube refrigerator shell and tube regenerator structure 10 provided by the present invention, the first shell and tube structure 500 includes a first shell and tube 510 and a room temperature end heat exchanger 520. The first shell and tube 510 is provided with a first opening 512 at one end away from the secondary heat exchanger. The first opening 512 is connected to the first accommodating cavity 511, and the room temperature end heat exchanger 520 is blocked at the first opening 512.

[0037] It is understood that the first sleeve 510 provides a closed accommodation space for the first-stage cold storage filler 700 and serves as a channel for gas flow. The first sleeve 510 is located in the first installation cavity 110, and its design allows the cold storage filler to be installed or replaced as a whole. A first opening 512 is provided at one end thereof, and this opening is connected to the first accommodation cavity 511, so that the cold storage filler can be placed or removed.

[0038] The first opening 512 provides an entrance to the first accommodating chamber 511 so that the cold storage filler can be easily installed or replaced. The first opening 512 is located at an end of the first sleeve 510 away from the secondary regenerator and communicates with the first accommodating chamber 511 .

[0039] The room temperature end heat exchanger 520 plays a dual role of blocking and heat exchange in the first sleeve structure 500. The room temperature end heat exchanger 520 is blocked at the first opening 512, which can not only block the primary cold storage material in the first accommodating cavity 511, but also, as a part of heat exchange, better transfer the heat from the low temperature end to the environment. While ensuring the integrity of the thermodynamic cycle of the pulse tube refrigerator, it also provides convenience for the replacement of cold storage fillers.

[0040] Reference Figure 1 and Figure 2 According to a pulse tube refrigerator shell and tube regenerator structure 10 provided by the present invention, a first connection hole 513 is provided on the outer wall of the first shell and tube 510 near the first opening 512, and a second connection hole 521 is provided at the room temperature end heat exchanger corresponding to the position of the first connection hole 513, and a fastener 600 passes through the first connection hole 513 and the second connection hole 521 to connect and fix the first shell and tube 510 to the room temperature end heat exchanger.

[0041] It is understandable that the first connection hole 513 is located on the outer side wall of the first sleeve 510 near the first opening 512, and provides a mechanical connection point for fixing the first sleeve 510 and the room temperature end heat exchanger 520 together. The design of the first connection hole 513 allows the fastener 600 (such as a bolt, a screw or a screw, etc.) to pass through, thereby achieving the mechanical connection between the first sleeve 510 and the room temperature end heat exchanger 520. It ensures that during the operation of the refrigerator, the sleeve structure can remain stable and will not be displaced due to vibration or other external forces.

[0042] The second connection hole 521 is located on the room temperature end heat exchanger 520, corresponding to the first connection hole 513 of the first sleeve 510, and is also a hole for mechanical connection. The existence of the second connection hole 521 allows the fastener 600 to pass through the room temperature end heat exchanger 520 and the first sleeve 510 to complete the fixed connection between the two. The corresponding design ensures the accuracy and reliability of the connection.

[0043] Of course, in other embodiments, multiple first connection holes may be provided along the circumferential direction of the first sleeve 510 near one end of the first opening 512, and the corresponding room temperature end heat exchanger may be provided with multiple second connection holes 521, which is not specifically limited here.

[0044] The fastener 600 (such as a bolt, a screw, etc.) is used to pass through the first connection hole 513 and the second connection hole 521 to tightly connect and fix the first sleeve 510 to the room temperature end heat exchanger 520. The use of the fastener 600 provides the necessary clamping force to ensure that the connection between the first sleeve 510 and the room temperature end heat exchanger 520 is firm and will not leak or loosen due to temperature changes or vibrations during the refrigeration process.

[0045] Reference Figure 1 and Figure 2 According to a pulse tube refrigerator shell and tube regenerator structure 10 provided by the present invention, a threaded hole 522 is provided on the side of the room temperature end heat exchanger away from the first sleeve 510, and the threaded hole 522 is used to cooperate with the bolt to remove the first sleeve structure 500 from the first installation cavity 110.

[0046] It is understandable that the threaded hole 522 is located on the side of the room temperature end heat exchanger away from the first sleeve 510, and it provides a mechanical operation interface for removing the first sleeve structure 500 from the first installation cavity 110 when maintaining or replacing the cold storage filler. The threaded hole 522 is provided with a thread inside, which can cooperate with the thread of the bolt to form a reliable locking mechanism.

[0047] When the cold storage filler needs to be replaced, the operator can screw the bolt into the threaded hole 522, and through the axial force generated by rotating the bolt, the first sleeve structure 500 can be smoothly pulled out from the first installation cavity 110. This can avoid damage or deformation that may be caused by directly applying force to the sleeve structure.

[0048] Reference Figure 1 According to a pulse tube refrigerator shell and tube regenerator structure 10 provided by the present invention, a first shell and tube 510 is provided with a cold end vent hole 514 at the end close to one end of the primary heat exchanger 300, and a hot end vent hole 523 is provided on the room temperature end heat exchanger, and both the cold end vent hole 514 and the hot end vent hole 523 are connected to the first accommodating cavity 511.

[0049] It is understandable that the cold end vent hole 514 is located at the end of the first sleeve 510 close to one end of the primary heat exchanger 300 to allow gas to flow into or out of the first sleeve 510 from the primary heat exchanger 300 during the refrigeration cycle.

[0050] The cold end vent hole 514 ensures that the refrigerator gas can flow between the primary heat exchanger 300 and the first sleeve 510 to achieve effective heat exchange.

[0051] The cold end vent hole 514 is in communication with the first accommodating chamber 511 , so that gas can flow in the cold storage filler, thereby utilizing the heat capacity of the filler to store and release heat.

[0052] The hot-end vent hole 523 is located on the room-temperature-end heat exchanger, and allows gas to flow into or out of the room-temperature-end heat exchanger 520 from the first casing 510 during the refrigeration cycle.

[0053] The hot-end vent hole 523 ensures that the refrigerator gas can flow between the first sleeve 510 and the room-temperature-end heat exchanger 520 .

[0054] The hot end vent hole 523 is in communication with the first accommodating chamber 511, so that the gas can form a continuous flow path in the entire regenerator, thereby improving the heat exchange efficiency.

[0055] Reference Figure 1 According to a pulse tube refrigerator shell and tube regenerator structure 10 provided by the present invention, an annular sealing groove 515 is opened on the outer wall of the first sleeve 510, and the pulse tube refrigerator shell and tube regenerator structure 10 includes a sealing member, which is arranged in the sealing groove 515 and abuts between the inner wall surface of the first installation cavity 110 and the outer side surface of the first sleeve structure 500.

[0056] It is understandable that the annular sealing groove 515 is formed on the outer wall of the first sleeve 510 to provide a mounting position for the sealing member to ensure the sealing between the first sleeve 510 and the first mounting cavity 110 .

[0057] The sealing member is disposed around the sealing groove 515 and abuts between the inner wall surface of the first installation cavity 110 and the outer side surface of the first sleeve structure 500. The sealing member is usually made of elastic material, such as rubber or silicone, and has good elasticity and sealing performance.

[0058] The main function of the seal is to prevent the working gas from leaking from the gap between the first sleeve 510 and the first installation cavity 110. During the operation of the pulse tube refrigerator, the working gas at the cold end and the hot end is prevented from directly exchanging heat and losing cooling capacity.

[0059] In some embodiments, the primary regenerator tube wall 100, the primary cold end copper block 200 and the secondary regenerator tube wall 400 are integrally connected.

[0060] It can be understood that the integral connection means that the primary regenerator tube wall 100, the primary cold end copper block 200 and the secondary regenerator tube wall 400 are integrally connected together by welding process to form a relatively stable integral structure, thereby improving the mechanical strength, heat conduction efficiency and air tightness of the pulse tube refrigerator structure.

[0061] In some embodiments, the shell-and-tube regenerator structure 10 of the pulse tube refrigerator also includes a second shell-and-tube structure, which is interference-fitted in the second installation cavity 410. The second shell-and-tube structure has a second accommodating cavity and a second opening connected to the second accommodating cavity. The second accommodating cavity is used to place the secondary cold storage filler 800, and the primary heat exchanger 300 is sealed at the second opening.

[0062] It is understandable that, similar to the design of the first sleeve structure 500, the second sleeve structure makes it easier to replace the secondary cold storage filler 800. By means of interference fit, it is ensured to be firmly installed in the second installation cavity 410, and is easy to quickly disassemble and reinstall, simplifying the maintenance process.

[0063] The second sleeve structure is made of non-metallic materials, which effectively reduces the heat leakage between the working gas, cold storage filler and the regenerator tube wall, and improves the heat exchange efficiency. A sealing groove 515 can be set on the second sleeve structure to ensure that the working gas at the cold and hot ends will not cross each other, avoiding problems such as unstable temperature control and heat leakage.

[0064] The second accommodating chamber provides a safe and stable storage space for the secondary cold storage filler 800 (such as metal particles of different particle sizes). When the secondary cold storage filler 800 needs to be replaced or cleaned, the filler therein can be directly dumped or replaced by simply pulling out the second sleeve structure, which greatly simplifies the operation steps.

[0065] The second opening is directly connected to the second accommodating cavity, so that the filling and replacement of the secondary cold storage filler 800 is more convenient without complicated disassembly and assembly steps.

[0066] The primary heat exchanger 300 acts as a plugging component to ensure the sealing of the cold storage filler inside the second sleeve structure and maintain the pressure balance and temperature control of the system. The primary heat exchanger 300 not only plays a plugging role, but is also an important heat exchange component, and can effectively achieve the reasonable distribution of the first and second stage working fluid gas volume of the refrigerator to ensure the effective use of cold capacity.

[0067] In summary, this embodiment introduces a second sleeve structure and interference fits it in the second installation cavity 410, so that in a low-temperature scientific instrument and a dilution refrigerator system, the cold storage fillers in the first-stage regenerator and the second-stage regenerator can be quickly removed and replaced without removing the entire pulse tube refrigerator.

[0068] The present invention also provides a method for replacing the cold storage filler of the shell-and-tube regenerator structure 10 of the pulse tube refrigerator as described above, and the cold storage filler replacement method comprises the following steps: Use bolts to pull the entire first sleeve structure 500 out of the first installation cavity 110 through the threaded holes 522; After taking out the first sleeve structure 500, disassemble the screw, remove the room temperature end heat exchanger 520, and replace the primary cold storage filler 700 in the first accommodating cavity 511; Take out the primary heat exchanger 300 and replace the secondary cold storage filler 800 in the second installation cavity 410; After the secondary cold storage filler 800 in the second installation cavity 410 is replaced, the primary heat exchanger 300 is installed back into the communication channel 210; The first sleeve structure 500 after replacing the first-level cold storage filler 700 is interference-fitted into the first installation cavity 110 .

[0069] When replacing the cold storage filler in the second installation cavity 410, it is determined whether there is a second sleeve structure. If yes, then after taking out the second sleeve structure, replace the second cold storage filler 800 in the second accommodation cavity of the second sleeve structure; If not, the secondary cold storage filler 800 in the second installation cavity 410 is directly poured out from the refrigerator.

[0070] The room temperature end stainless steel flange 900, the primary regenerator tube wall 100, the primary cold end copper block 200, the secondary regenerator tube wall 400 and the secondary cold end copper block (not shown in the figure) are integrally welded together.

[0071] Specifically, the first sleeve structure is pulled out from the first-stage heat regenerator tube wall 100 by using a bolt through the threaded hole 522, and then the first-stage heat exchanger 300 is taken out, and the granular cold storage material in the second-stage heat regenerator can be directly poured out from the refrigerator. After taking out the sleeve structure, the screw is disassembled, and the room temperature end heat exchanger 520 is taken down, and the first-stage cold storage filler 700 in the first accommodating chamber 511 can be replaced. If the second-stage heat regenerator uses a second sleeve structure, the second sleeve structure is pulled out from the second-stage heat regenerator tube wall 400 using the same method as the first sleeve structure is removed, so as to replace the second-stage cold storage filler 800 in the second accommodating chamber, and it is no longer necessary to remove the refrigerator for pouring, which can avoid the refrigerator from being repeatedly disassembled and assembled from more complex low-temperature scientific instruments and dilution refrigerator systems. The installation process is the reverse process of the disassembly process.

[0072] 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pipe-in-tube regenerator structure of a pulse tube refrigerator, characterized in that: include: A first-stage heat regenerator tube wall, wherein a first installation cavity penetrating along the axial direction is formed in the first-stage heat regenerator tube wall; A secondary heat regenerator tube wall, wherein the secondary heat regenerator tube wall is coaxial with the primary heat regenerator tube wall and spaced apart from each other, and a second installation cavity is provided in the secondary heat regenerator tube wall along the axial direction; A primary cold-end copper block, the primary cold-end copper block is respectively connected to the outer side walls of the primary regenerator tube wall and the secondary regenerator tube wall at adjacent ends, and a connecting passage connecting the first installation cavity and the second installation cavity is provided in the primary cold-end copper block; a primary heat exchanger, the primary heat exchanger being detachably disposed in the communication channel; A first sleeve structure is interference-fitted in the first installation cavity. A first accommodating cavity is formed in the first sleeve structure, and the accommodating cavity is used to place a first-level cold storage filler.

2. The shell-and-tube regenerator structure of the pulse tube refrigerator according to claim 1, characterized in that: The first sleeve structure includes a first sleeve and a room temperature end heat exchanger. The first sleeve is provided with a first opening at one end away from the secondary heat regenerator. The first opening is communicated with the first accommodating cavity. The room temperature end heat exchanger is sealed at the first opening.

3. The shell-and-tube regenerator structure of the pulse tube refrigerator according to claim 2, characterized in that: A first connecting hole is provided on the outer wall of the first sleeve near one end of the first opening, and a second connecting hole is provided on the room temperature end heat exchanger corresponding to the position of the first connecting hole. A fastener passes through the first connecting hole and the second connecting hole to connect and fix the first sleeve to the room temperature end heat exchanger.

4. The shell-and-tube regenerator structure of the pulse tube refrigerator according to claim 2, characterized in that: A threaded hole is provided on a side of the room temperature end heat exchanger facing away from the first sleeve, and the threaded hole is used to cooperate with bolts to remove the first sleeve structure from the first installation cavity.

5. The shell-and-tube regenerator structure of the pulse tube refrigerator according to claim 2, characterized in that: A cold end vent hole is formed at the end of the first sleeve close to one end of the primary heat exchanger, and a hot end vent hole is formed on the room temperature end heat exchanger. Both the cold end vent hole and the hot end vent hole are connected to the first accommodating cavity.

6. The shell-and-tube regenerator structure of the pulse tube refrigerator according to claim 5, characterized in that: An annular sealing groove is provided on the outer wall of the first sleeve, and the sleeve-type heat regenerator structure of the pulse tube refrigerator includes a sealing member, which is arranged in the sealing groove and abuts between the inner wall surface of the first installation cavity and the outer side surface of the first sleeve structure.

7. The shell-and-tube regenerator structure of a pulse tube refrigerator according to any one of claims 1 to 6, characterized in that: The first-stage heat regenerator tube wall, the first-stage cold end copper block and the second-stage heat regenerator tube wall are integrally connected.

8. The shell-and-tube regenerator structure of a pulse tube refrigerator according to any one of claims 1 to 6, characterized in that: The shell-and-tube regenerator structure of the pulse tube refrigerator also includes a second shell-and-tube structure, which is interference-fitted in the second installation cavity. The second shell-and-tube structure has a second accommodating cavity and a second opening connected to the second accommodating cavity. The second accommodating cavity is used to place a secondary cold storage filler, and the primary heat exchanger is sealed at the second opening.

9. A method for replacing the cold storage filler of the shell-and-tube regenerator structure of a pulse tube refrigerator according to any one of claims 1 to 8, characterized in that: The cold storage filler replacement method comprises the following steps: Use bolts to pull the entire first sleeve structure out of the first installation cavity through the threaded holes; Take out the primary heat exchanger and determine whether there is a second sleeve structure in the second installation cavity. If so, take out the second sleeve structure and then replace the secondary cold storage filler in the second accommodation cavity of the second sleeve structure; if not, directly pour out the secondary cold storage filler in the second installation cavity from the refrigerator; After the secondary cold storage filler in the second installation cavity is replaced, install the primary heat exchanger back into the communication channel; The first sleeve structure is interference fitted into the first installation cavity.

10. The method for replacing the cold storage filler according to claim 9, characterized in that: After taking out the first sleeve structure, disassemble the screw, remove the room temperature end heat exchanger, and replace the primary cold storage filler in the first accommodating cavity.

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