An expander inlet structure for a stirling cryocooler and a stirling cryocooler

Abstract

The application provides an expander gas inlet structure for a Stirling refrigerator and the Stirling refrigerator. The expander gas inlet structure comprises a push piston, the push piston comprises a rod part and a plug part; the plug part of the push piston comprises a plurality of inclined circular hole air channels, a plurality of first slit air channels in communication with the inclined circular hole air channels are arranged at an end of the plug part away from the rod part, the plurality of first slit air channels are uniformly distributed around a central axis of the push piston and meet at the central axis of the push piston; a conical recessed surface is arranged on an end surface of the plug part away from the rod part at the meeting position of the plurality of first slit air channels; the push piston is connected with a hot end of a regenerator; a plurality of second slit air channels are arranged on a cold end of the regenerator, the plurality of second slit air channels are uniformly distributed around a central axis of the regenerator and meet at the central axis of the regenerator. The application has the advantages of simple structure, easy processing, effective enhancement of the laminar flow state of the working medium at the cold end and the hot end of the regenerator, reduction of the flow resistance and the vortex loss, and improvement of the refrigeration efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of Stirling refrigerators, and in particular to an expander air intake structure for a Stirling refrigerator and a Stirling refrigerator. Background Art

[0002] As a highly efficient and environmentally friendly refrigeration device, the Stirling refrigerator is increasingly being used in aerospace, security, gas leak detection, and other fields, along with the rapid development of infrared detector components. It is a crucial technological product in infrared detector assemblies. The Stirling refrigerator operates on the Stirling cycle, achieving cooling through the compression and expansion of gas. The regenerator, one of the most important moving components in a Stirling refrigerator, accounts for over 60% of the total energy loss, making its heat recovery efficiency crucial to cooling performance.

[0003] In Stirling refrigerators, the regenerator is typically filled with heat-exchange materials such as stainless steel mesh. The pressure waves generated by the compressor drive the working fluid to oscillate back and forth between the hot and cold ends of the regenerator, exchanging heat with the regenerator packing and generating a cooling effect. The working fluid experiences significant flow resistance as it moves through the regenerator. This is caused, on the one hand, by interaction with the regenerator mesh, and on the other hand, by eddy currents generated by the regenerator structure as the working fluid enters and exits the regenerator. These two factors affect the overall cooling performance of the refrigerator, increase power consumption, and prolong the cooling time required to reach the desired low temperature. Summary of the Invention

[0004] The present invention provides an expander air intake structure for a Stirling refrigerator and a Stirling refrigerator, which solves the problem of how to reduce the energy loss of the Stirling refrigerator and improve the refrigeration efficiency.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, an expander air intake structure for a Stirling refrigerator is provided, comprising:

[0007] a pneumatic chamber for accommodating the piston assembly and the regenerator;

[0008] The piston assembly includes a push piston and a push piston cylinder sleeve;

[0009] The push piston includes a rod portion and a plug portion;

[0010] The plug portion of the push piston comprises a plurality of inclined circular hole air passages uniformly distributed around the central axis of the push piston, the plurality of inclined circular hole air passages extend to the plug portion along the end face of the plug portion close to the rod portion and meet at a predetermined position of the central axis of the push piston; the end of the plug portion away from the rod portion is provided with a plurality of first slit air passages in communication with the inclined circular hole air passages, the plurality of first slit air passages are uniformly distributed around the central axis of the push piston and meet at the central axis of the push piston; the end face of the plug portion away from the rod portion is provided with a conical recess at the meeting position of the plurality of first slit air passages.

[0011] The push piston is fixedly connected with the hot end of the regenerator; the cold end of the regenerator is provided with a plurality of second slit air passages, the plurality of second slit air passages are uniformly distributed around the central axis of the regenerator and meet at the central axis of the regenerator.

[0012] In a first possible implementation manner of the first aspect, the push piston sleeve comprises a piston cavity for accommodating the push piston; the push piston sleeve is sleeved on the rod portion of the push piston, and the plug portion of the push piston is arranged in the piston cavity to form a piston structure; the end of the push piston away from the plug portion extends out of the piston cavity and is fixedly connected with an elastic member for providing a restoring force of the push piston; the piston cavity is provided with a first air passage for communication with the pneumatic chamber; the pneumatic chamber is provided with a second air passage for connecting a connecting pipe, and the connecting pipe is used for connecting a compressor for providing a pushing force of the push piston.

[0013] In a second possible implementation manner of the first aspect based on any of the possible implementation manners of the first aspect, the slit width, length and number of the first slit air passages and the second slit air passages are determined according to the required cooling capacity and efficiency of the refrigerating machine.

[0014] In a third possible implementation manner of the first aspect, the inclined circular hole air passages are configured as four.

[0015] In a fourth possible implementation manner of the first aspect, the hot end of the regenerator is connected with the plug portion of the push piston through adhesive.

[0016] In a fifth possible implementation manner of the first aspect based on the first possible implementation manner of the first aspect, the elastic member is configured as a spring, the push piston sleeve is connected with the spring through laser welding, and the spring is connected with the rod portion of the push piston through threads and thread glue.

[0017] In a sixth possible implementation manner of the first aspect, the pneumatic chamber comprises an openable and closable pneumatic chamber end cover.

[0018] In a second aspect, a Stirling cryocooler is provided, comprising the expander gas inlet structure for a Stirling cryocooler according to the first aspect.

[0019] In a third aspect, an infrared device is provided, comprising the Stirling cryocooler according to the second aspect.

[0020] The structure of the present application is simple and easy to process; only the regenerator and the hot end piston plug structure are changed, which does not affect the original assembly relationship and sequence of the cryocooler, can effectively enhance the laminar flow state of the working medium at the cold end of the regenerator and the inlet and outlet of the hot end piston plug, reduce the flow resistance loss and vortex loss, improve the refrigeration efficiency of the Stirling cryocooler, thereby effectively enhancing the reliability and stability of the infrared assembly. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A cross-sectional view of an expander gas inlet structure for a Stirling cryocooler provided by an embodiment of the present application;

[0022] Figure 2 A schematic view of a first slit type gas passage of a piston plug part provided by an embodiment of the present application;

[0023] Figure 3 A schematic view of an inclined circular hole gas passage of a piston plug part provided by an embodiment of the present application;

[0024] Figure 4 A schematic view of a second slit type gas passage of a regenerator cold end provided by an embodiment of the present application.

[0025] REFERENCE NUMERALS:

[0026] Piston plug part 202; inclined circular hole gas passage 203; first slit type gas passage 204; conical recess surface 205; piston cylinder sleeve 3; piston cavity 301; first gas passage 302; elastic member 4; connecting pipe 5; regenerator 6; second slit type gas passage 601; expansion cavity 7; cold head 8. DETAILED DESCRIPTION

[0027] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined purposes, the technical solutions in the embodiments of the present application are described clearly. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0028] The terms "first", "second", and the like in the description and in the claims of the present application are used for distinguishing between similar objects and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the present application are, for example, capable of practical implementation in other than the illustrated order, and / or configurations, and the like. Additionally, the terms "first", "second", and the like, are used herein, for example, to designate one element from another, without necessarily limiting those elements. For example, a first element can comprise one or more of the same type as a second element, and so on.

[0029] The description of the method flow in the specification of the present application and the steps of the flow chart in the drawings of the present application are not necessarily strictly executed in the order of the steps, and the method steps can change the order of execution. Moreover, certain steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be divided into multiple steps for execution.

[0030] The expansion machine inlet structure for a Stirling cryocooler provided by the embodiments of the present application will be described in detail below in combination with the drawings and preferred embodiments.

[0031] First, the application scenarios of the expansion machine inlet structure for a Stirling cryocooler according to the embodiments of the present application will be described in detail.

[0032] In the related art known to the inventors, the Stirling cryocooler regenerator 6 cold end structure and the displacer 2 are generally circular hole type and are processed from PEEK material or metal material. The pressure fluctuation generated by the compressor drives the working medium (working medium) to move back and forth inside the regenerator 6. In this process, the working medium will contact the filler inside the regenerator 6, thereby realizing heat transfer from one end to the other end to achieve the refrigeration effect.

[0033] Based on the technical solution that the heater cold end and the displacer 2 structure are circular hole type inlet structures in the related art, the working medium entering and exiting will generate a certain flow resistance, and at the same time will also cause vortex flow of the working medium at the cold and hot ends. When the working medium passes through the regenerator 6, especially when it interacts with the internal filler, resistance will be generated, which is called flow resistance loss. The irregular flow (vortex flow) of the working medium entering and exiting the regenerator 6 due to the structure design reason will also cause energy loss, i.e., vortex loss. In infrared applications, the above phenomenon will cause the Stirling cryocooler to have large power consumption and long cooling time, which reduces the refrigeration efficiency, and further causes the entire infrared generating assembly to have high power consumption and even cannot image.

[0034] In order to reduce the energy loss of the two forms and improve the refrigeration efficiency, the application optimizes the structure of the regenerator 6 and the cold head 8 of the Stirling refrigerator and changes the circular hole type flow channel in the related art to the slit type structure, avoids the large flow resistance loss and vortex of the working medium when entering and leaving the regenerator 6, improves the refrigeration performance and stability of the Stirling refrigerator, and further reduces the power consumption of the entire infrared assembly and improves the reliability of the infrared assembly.

[0035] Please refer to Figures 1-4 The embodiment of the application provides an expander gas inlet structure for a Stirling refrigerator. Figures 1-4 As shown in the figure, the expander gas inlet structure of the embodiment of the application comprises:

[0036] The pneumatic chamber 1 is used for accommodating the piston assembly and the regenerator 6.

[0037] The piston assembly comprises the displacement piston 2 and the displacement piston sleeve 3.

[0038] The displacement piston 2 comprises a rod part 201 and a plug part 202; the displacement piston sleeve 3 comprises a piston cavity 301 for accommodating the displacement piston 2; the displacement piston sleeve 3 is sleeved on the rod part 201 of the displacement piston 2, and the plug part 202 of the displacement piston 2 is arranged in the piston cavity 301, forming a piston structure; one end of the displacement piston 2 away from the plug part 202 extends out of the piston cavity 301 and is fixedly connected with the elastic member 4 for providing a reset force of the displacement piston 2; the piston cavity 301 is provided with a first air duct 302 for communicating with the pneumatic chamber 1; the pneumatic chamber 1 is provided with a second air duct 101 for connecting the connecting pipe 5, and the connecting pipe 5 is used for connecting with a compressor for providing a pushing force of the displacement piston 2.

[0039] The plug part 202 of the displacement piston 2 comprises a plurality of inclined circular hole air ducts 203 uniformly distributed around the central axis of the displacement piston 2, and the plurality of inclined circular hole air ducts 203 extend to the plug part 202 along the end face of the plug part 202 close to the rod part 201 and meet at a specified position of the central axis of the displacement piston 2; the end of the plug part 202 away from the rod part 201 is provided with a plurality of first slit type air ducts 204 in communication with the inclined circular hole air ducts 203, and the plurality of first slit type air ducts 204 are uniformly distributed around the central axis of the displacement piston 2 and meet at the central axis of the displacement piston 2; the end face of the plug part 202 away from the rod part 201 is provided with a conical recessed surface 205 at the meeting position of the plurality of first slit type air ducts 204.

[0040] The displacement piston 2 is fixedly connected with the hot end of the regenerator 6; the cold end of the regenerator 6 is provided with a plurality of second slit type air ducts 601, and the plurality of second slit type air ducts 601 are uniformly distributed around the central axis of the regenerator 6 and meet at the central axis of the regenerator 6.

[0041] The working principle of the application is that:

[0042] After the working gas is compressed in the compressor, it enters the expander through the connecting pipe 5. The gas passes through the second gas channel 101, the pneumatic chamber 1, the first gas channel 302 into the piston cavity 301 in turn, and then passes through the inclined circular hole gas channel 203 and the first slit gas channel 204 into the regenerator 6 to release heat to the filler of the regenerator 6. At this time, the temperature and pressure of the working gas are reduced, and then the working gas enters the expansion cavity 7 through the second slit gas channel 601 to expand and refrigerate, and the cold head 8 is used to guide out the cold. After the expansion, the gas flows back to the inside of the regenerator 6 to absorb the heat of the filler, at which time the temperature and pressure of the working gas are increased, and finally the working gas flows back to the compressor to be compressed again to complete a cycle.

[0043] In the above process, the cold end flow channel structure of the regenerator 6 and the plug flow channel structure of the hot end push piston 2 are optimized. The traditional circular hole structure is changed to the slit structure as shown in Figure 2 and Figure 4 , so that the internal working fluid enters and exits the regenerator 6 in a laminar flow manner to avoid vortex at the inlet and outlet; the structure of the present application can effectively enhance the laminar flow state of the working fluid at the inlet and outlet of the cold end of the regenerator 6 and the plug of the hot end push piston 2, improve the refrigeration efficiency of the Stirling refrigerator, and finally effectively enhance the reliability and stability of the infrared assembly.

[0044] In some possible embodiments, the slit width, length and number of the first slit gas channel 204 and the second slit gas channel 601 are determined according to the required cold capacity and efficiency of the refrigerator. For different refrigerators, different width and number of slits can be used to maximize the performance of the Stirling refrigerator.

[0045] In some possible embodiments, the inclined circular hole gas channel 203 can be configured in a combination of 4 or 6.

[0046] In some possible embodiments, the plug part 202 of the hot end of the regenerator 6 and the push piston 2 are connected by adhesive to fix the relative position of the regenerator 6 and the push piston 2. In some possible embodiments, the elastic member 4 can be configured as a spring, the push piston sleeve 3 and the spring are connected by laser welding, and the spring and the rod part 201 of the push piston 2 are connected by threads and thread glue. The effective operation of the expander is ensured by the connection between the various components.

[0047] In some possible embodiments, the pneumatic chamber 1 includes an openable and closable pneumatic chamber 1 end cover.

[0048] In summary, the present application has simple structure and is easy to process; only the regenerator and the hot end push piston plug structure are changed, which does not affect the original assembly relationship and order of the refrigerator, can effectively enhance the laminar flow state of the working medium at the cold end of the regenerator and the hot end push piston plug inlet and outlet, reduce the flow resistance loss and vortex loss, improve the refrigeration efficiency of the Stirling refrigerator, and thus effectively enhance the reliability and stability of the infrared assembly.

[0049] It should be noted that in this document, the terms "comprising", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. In addition, it should be pointed out that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but can also include performing functions in a substantially simultaneous manner or in reverse order, for example, the described method can be performed in an order different from that described, and various steps can also be added, omitted, or combined. In addition, the features described with reference to certain examples can be combined in other examples.

[0050] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above-described specific embodiments, which are only illustrative and not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope protected by the claims.

Claims

1. An expander air intake structure for a Stirling refrigerator, characterized in that: include: a pneumatic chamber for accommodating the piston assembly and the regenerator; The piston assembly includes a push piston and a push piston cylinder sleeve; The push piston includes a rod portion and a plug portion; The plugging portion of the push piston includes a plurality of inclined circular hole air passages evenly distributed around the central axis of the push piston, and the plurality of inclined circular hole air passages extend along the end surface of the plugging portion close to the rod portion into the plugging portion and intersect at a set position of the central axis of the push piston; the end of the plugging portion away from the rod portion is provided with a plurality of first slit-type air passages connected to the inclined circular hole air passages, and the plurality of first slit-type air passages are evenly distributed around the central axis of the push piston and intersect at the central axis of the push piston; the end surface of the plugging portion away from the rod portion is provided with a conical concave surface at the intersection of the plurality of first slit-type air passages; The push piston is fixedly connected to the hot end of the regenerator; the cold end of the regenerator is provided with a plurality of second slit air ducts, which are evenly distributed around the central axis of the regenerator and intersect at the central axis of the regenerator.

2. The expander air intake structure for a Stirling refrigerator according to claim 1, characterized in that: The push piston cylinder sleeve includes a piston chamber for accommodating the push piston; the push piston cylinder sleeve is sleeved on the rod portion of the push piston and the plug portion of the push piston is placed in the piston chamber to form a piston structure; one end of the push piston away from the plug portion extends to the outside of the piston chamber and is fixedly connected to an elastic member for providing a reset force for the push piston; the piston chamber is provided with a first air channel for communicating with the pneumatic chamber; the pneumatic chamber is provided with a second air channel for connecting to a connecting pipe, and the connecting pipe is used to be connected to a compressor to provide a driving force for the push piston.

3. The expander air intake structure for a Stirling refrigerator according to claim 1 or 2, characterized in that: The slit width, length and number of the first slit air duct and the second slit air duct are determined according to the required cooling capacity and efficiency of the refrigerator.

4. The expander air intake structure for a Stirling refrigerator according to claim 1, characterized in that: The number of the inclined circular hole airways is 4.

5. The expander air intake structure for a Stirling refrigerator according to claim 1, characterized in that: The hot end of the regenerator is connected to the plugging portion of the push piston by adhesive.

6. The expander air intake structure for a Stirling refrigerator according to claim 2, characterized in that: The elastic member is configured as a spring, the push piston cylinder sleeve and the spring are connected by laser welding, and the spring and the rod portion of the push piston are connected by threads and thread glue.

7. The expander air intake structure for a Stirling refrigerator according to claim 1, characterized in that: The pneumatic chamber includes an openable and closable pneumatic chamber end cover.

8. A Stirling refrigerator, characterized in that: The invention comprises an expander air intake structure for a Stirling refrigerator as described in any one of claims 1 to 7.

9. An infrared device, characterized in that: Comprising the Stirling refrigerator as claimed in claim 8.

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