Free piston Stirling device

Abstract

The present application relates to the field of heat exchange technology, and in particular to a free piston Stirling device. It aims to solve the problem that the free piston Stirling device has low heat exchange efficiency and poor economy in small temperature difference refrigeration or pump heat occasions. It comprises a shell with a working chamber, and a second resonance component, a first heat exchange component and a first resonance component are sequentially arranged in the working chamber at intervals, and a second heat exchange component is arranged at the opening of the shell to block the working chamber, thereby making the overall structure flat. Such an arrangement can not only simplify the internal structure and connection relationship of the free piston Stirling device, reduce the power density, and thus reduce the heat exchange temperature difference, improve the heat exchange efficiency, thereby improving the economy of the free piston Stirling device in small temperature difference refrigeration or pump heat occasions, but also reduce the difficulty and cost of processing and manufacturing the free piston Stirling device, and further improve the economy of the free piston Stirling device in small temperature difference refrigeration or pump heat occasions.

Description

Technical Field

[0001] The present application relates to the field of heat exchange technology, and in particular to a free piston Stirling device. Background Art

[0002] The free piston Stirling device used as a refrigerator has been widely used in large temperature difference heat exchange occasions with compactness and high reliability requirements.

[0003] In the related technology, almost all free piston Stirling devices are designed in a relatively complex and compact form, and are filled with a working gas at a higher pressure to obtain a higher power density. The higher power density can make the heat exchange energy flow density of the free piston Stirling device larger during internal and external heat exchange, thereby forming a larger heat exchange temperature difference.

[0004] However, the above-mentioned free piston Stirling device has a low heat exchange efficiency and is less economical to use in small temperature difference refrigeration or pump heat applications. Summary of the Invention

[0005] The present application provides a free piston Stirling device, which aims to solve the problem that the free piston Stirling device has low heat exchange efficiency and poor economy when used in small temperature difference refrigeration or pump heat occasions.

[0006] To achieve the above objectives, the present application provides a free-piston Stirling device, comprising a housing, a first heat exchange element, and a second heat exchange element. The housing has a working chamber filled with a working medium. The first heat exchange element is disposed in the working chamber, and the second heat exchange element is disposed at an opening of the housing and blocks the working chamber.

[0007] A first resonant component and a second resonant component connected to the shell are provided in the working chamber, the first resonant component is located on a side of the first heat exchanger away from the second heat exchanger, and the second resonant component is located between the first heat exchanger and the second heat exchanger;

[0008] A first cavity is formed between the first resonant component and the second resonant component, the first heat exchange element is located in the first cavity, and a second cavity is formed between the second resonant component and the second heat exchange element;

[0009] The second resonant component is provided with a channel connecting the first cavity and the second cavity, the shell is provided with a mounting hole connecting the working cavity and the outside of the shell, and at least part of the first heat exchange element extends to the outside of the shell through the mounting hole.

[0010] The free piston Stirling device provided in the present application includes a housing having a working chamber, wherein a second resonant assembly, a first heat exchanger, and a first resonant assembly are sequentially arranged in the working chamber at intervals, and a second heat exchanger is arranged at an opening of the housing to block the working chamber, wherein the working chamber is filled with a working medium, and a channel for the working medium is provided on the second resonant assembly, thereby making the overall structure flat. This arrangement not only simplifies the internal structure and connection relationship of the free piston Stirling device, reduces power density, thereby reducing the heat exchange temperature difference, and improving heat exchange efficiency, thereby improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat applications, but also reduces the difficulty and cost of manufacturing the free piston Stirling device, further improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat applications.

[0011] In the above-mentioned free piston Stirling device, optionally, the first heat exchange member is a tubular member, the first heat exchange member located in the working chamber is provided with a first heat exchange fin, and the first heat exchange member located outside the working chamber is provided with a second heat exchange fin;

[0012] In the above-mentioned free piston Stirling device, optionally, the second heat exchange member is a plate-shaped member;

[0013] A second heat exchange element is provided with a plurality of third heat exchange fins spaced apart on a side away from the first heat exchange element, and a side of the second heat exchange element close to the first heat exchange element is a flat surface;

[0014] Alternatively, a surface of the second heat exchange element away from the first heat exchange element is provided with a plurality of third heat exchange fins distributed at intervals, and a surface of the second heat exchange element close to the first heat exchange element is provided with a plurality of third heat exchange fins distributed at intervals;

[0015] Alternatively, a surface of the second heat exchange element away from the first heat exchange element is a plane, and a surface of the second heat exchange element close to the first heat exchange element is provided with a plurality of third heat exchange fins distributed at intervals;

[0016] Alternatively, a surface of the second heat exchange element away from the first heat exchange element is a plane, and a surface of the second heat exchange element close to the first heat exchange element is a plane.

[0017] In the above-mentioned free piston Stirling device, optionally, the first resonant component includes a drive component, a first elastic member and a piston, the first end of the drive component is connected to the inner wall surface of the shell, the second end of the drive component is connected to the piston, the first elastic member is connected between the drive component and the piston, and the drive component is used to drive the piston to move back and forth between the first heat exchange component and the drive component.

[0018] In the above-mentioned free piston Stirling device, optionally, the drive assembly includes an electromagnetic driver, a stator assembly, and an electromagnetic driver, the electromagnetic driver is connected to the housing, the stator assembly is disposed inside the electromagnetic driver, and the electromagnetic driver is located outside the electromagnetic driver and connected to the piston;

[0019] The stator assembly includes silicon steel sheets and coils, and the coils are arranged on the silicon steel sheets.

[0020] In the above-mentioned free piston Stirling device, optionally, the second resonant component includes a regenerator, a second elastic member and an ejector, the ejector is connected to the inner wall surface of the shell through the second elastic member, and the regenerator is connected to the ejector.

[0021] In the above-mentioned free piston Stirling device, optionally, the regenerator is a columnar member, and the ratio of the axial length of the regenerator to the radial length of the regenerator is not greater than 0.5.

[0022] In the above-mentioned free piston Stirling device, optionally, the regenerator, the first heat exchange element and the second heat exchange element are arranged in parallel along the axis direction of the regenerator;

[0023] And / or, the central axis of the regenerator coincides with the central axis of the second heat exchange element.

[0024] In the above-mentioned free piston Stirling device, optionally, the pressure range of the working medium in the working chamber is 0.08-0.2 MPa.

[0025] In the above-mentioned free piston Stirling device, optionally, the working medium in the working chamber includes one or more of air, helium, hydrogen and nitrogen.

[0026] The structure of the present application and its other application objectives and beneficial effects will be more clearly understood through the description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 Schematic diagram of the structure of the free piston Stirling device provided in Example 1 of this application Figure 1 ;

[0029] Figure 2 Schematic diagram of the structure of the free piston Stirling device provided in Example 1 of this application Figure 2 ;

[0030] Figure 3 A schematic structural diagram of a regenerator of a free piston Stirling device provided in Example 1 of the present application;

[0031] Figure 4 A schematic structural diagram of a first heat exchange element of a free piston Stirling device provided in Example 1 of the present application;

[0032] Figure 5 A schematic structural diagram of the second heat exchange element of the free piston Stirling device provided in Example 1 of the present application;

[0033] Figure 6 This is a schematic structural diagram of the free piston Stirling device provided in Example 2 of the present application.

[0034] Description of reference numerals:

[0035] 10-housing; 11-first housing;

[0036] 12-second shell; 20-first heat exchange element;

[0037] 21-first heat exchange fin; 22-second heat exchange fin;

[0038] 30-second heat exchange element; 31-third heat exchange fin;

[0039] 40-first resonant component; 41-first elastic member;

[0040] 42-piston; 43-electromagnetic driver;

[0041] 44-stator assembly; 45-electromagnetic drive component;

[0042] 50-second resonant component; 51-regenerator;

[0043] 52-second elastic member; 53-ejector;

[0044] 54-center rod; 60-first cavity;

[0045] 70-Second cavity. DETAILED DESCRIPTION

[0046] The free piston Stirling device has been invented and applied to refrigerators for decades. Almost all free piston Stirling devices are designed in a relatively complex and compact form and are filled with high-pressure working gas to obtain a higher power density. Power density refers to the amount of cooling that can be generated by a unit volume of working gas. A higher power density will make the heat exchange energy flow density of the free piston Stirling device larger when performing internal and external heat exchange. The heat exchange energy flow density refers to the amount of heat that can be generated per unit heat exchange area, thereby forming a larger heat exchange temperature difference. Therefore, the above-mentioned free piston Stirling device is only used in large temperature difference refrigeration or pump heat occasions. Among them, pump heat refers to the transfer (pumping) of heat from a low-temperature medium to a high-temperature medium. At the same time, it is difficult to use the above-mentioned free piston Stirling device in small temperature difference refrigeration or pump heat occasions such as refrigerators and air conditioners. However, the free piston Stirling device has a complex structural design and requires compact installation. This, on the one hand, results in a large heat exchange temperature difference, resulting in low cooling efficiency of the entire device, reducing the economical use of the free piston Stirling device in small temperature difference refrigeration or pump heat applications. On the other hand, it increases the difficulty and cost of manufacturing, further reducing the economical use of the free piston Stirling device in small temperature difference refrigeration or pump heat applications. In addition, the high-pressure working gas filled in the free piston Stirling device increases the sealing and pressure resistance requirements of the free piston Stirling device, narrowing the range of materials and processing technologies for the free piston Stirling device, further reducing the economical use of the free piston Stirling device in small temperature difference refrigeration or pump heat applications.

[0047] Based on the above technical problems, the present application provides a free piston Stirling device, comprising a shell having a working chamber, wherein a second resonant component, a first heat exchange component and a first resonant component are sequentially arranged in the working chamber at intervals, and a second heat exchange component is arranged at the opening of the shell to block the working chamber, wherein the working chamber is filled with a working medium, and a channel for the working medium to pass through is provided on the second resonant component, thereby making the overall structure flat. Such an arrangement can not only simplify the internal structure and connection relationship of the free piston Stirling device, reduce power density, and thus reduce the heat exchange temperature difference, improve heat exchange efficiency, thereby improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat occasions, but also reduce the difficulty and cost of manufacturing the free piston Stirling device, further improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat occasions.

[0048] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0049] Example 1

[0050] Figure 1 Schematic diagram of the structure of the free piston Stirling device provided in Example 1 of this application Figure 1 . Figure 2 Schematic diagram of the structure of the free piston Stirling device provided in Example 1 of this application Figure 2 . Figure 3 This is a schematic structural diagram of the regenerator of the free piston Stirling device provided in Example 1 of the present application. Figure 4 This is a schematic structural diagram of the first heat exchange component of the free piston Stirling device provided in Example 1 of the present application. Figure 5 This is a schematic structural diagram of the second heat exchange component of the free piston Stirling device provided in Example 1 of the present application.

[0051] Reference Figures 1 to 5 As shown, the free piston Stirling device provided in the first embodiment of the present application includes a shell 10, a first heat exchanger 20 and a second heat exchanger 30. The shell 10 has a working chamber filled with a working medium. The first heat exchanger 20 is arranged in the working chamber, and the second heat exchanger 30 is arranged at the opening and blocks the working chamber. The working chamber is provided with a first resonant component 40 and a second resonant component 50 connected to the shell 10. The first resonant component 40 is located on a side of the first heat exchanger 20 away from the second heat exchanger 30, and the second resonant component 50 is located on a side of the first heat exchanger 20 away from the second heat exchanger 30. A first cavity 60 is formed between the first heat exchanger 20 and the second heat exchanger 30 and the first resonant component 40 and the second resonant component 50. The first heat exchanger 20 is located in the first cavity 60, and a second cavity 70 is formed between the second resonant component 50 and the second heat exchanger 30. The second resonant component 50 is provided with a channel connecting the first cavity 60 and the second cavity 70. The shell 10 is provided with a mounting hole connecting the working chamber and the outside of the shell 10. At least part of the first heat exchanger 20 extends to the outside of the shell 10 through the mounting hole.

[0052] The free piston Stirling device provided in the present application includes a housing 10 having a working chamber. A second resonant assembly 50, a first heat exchanger 20, and a first resonant assembly 40 are sequentially arranged in the working chamber at intervals, and a second heat exchanger 30 is arranged at the opening of the housing 10 to block the working chamber. The working chamber is filled with a working medium, and the second resonant assembly 50 is provided with a channel for the working medium to pass through, thereby making the overall structure flat. This arrangement not only simplifies the internal structure and connection relationship of the free piston Stirling device, reduces power density, thereby reducing the heat exchange temperature difference, and improving heat exchange efficiency, thereby improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat applications, but also reduces the difficulty and cost of manufacturing the free piston Stirling device, further improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat applications.

[0053] As a feasible embodiment, the first heat exchange element 20 is a tubular element. The first heat exchange element 20 located in the working chamber is provided with first heat exchange fins 21, and the first heat exchange element 20 located outside the working chamber is provided with second heat exchange fins 22.

[0054] It should be noted that the above-mentioned arrangement can improve the heat exchange efficiency of the first heat exchange element 20. The first heat exchange element 20 can be configured as a tubular heat exchanger, which is used to remove heat generated in the first cavity 60 at any time, so that the working medium is always at a lower temperature. By providing the first heat exchange fins 21 on the first heat exchange element 20 located in the working cavity, the heat exchange area of the working medium in the first cavity 60 can be increased, the heat exchange rate of the working medium in the first cavity 60 can be accelerated, and the heat of the working medium in the first cavity 60 can be transferred to the first heat exchange element 20 through contact heat exchange. By providing the second heat exchange fins 22 on the first heat exchange element 20 located outside the working cavity, the heat exchange area between the first heat exchange element 20 and the external gas can be increased, the heat release rate of the first heat exchange element 20 can be accelerated, and the heat of the first heat exchange element 20 can be transferred to the outside through contact heat exchange. For example, the first heat exchange element 20 can be a heat pipe heat exchanger that removes heat through gas, or a tube-fin heat exchanger that removes heat through fluid.

[0055] As a feasible implementation, the second heat exchange element 30 is a plate-shaped element.

[0056] It should be noted that configuring the second heat exchange element 30 as a plate-shaped element helps improve the heat exchange efficiency of the second heat exchange element 30. For example, the second heat exchange element 30 can be a plate-shaped radiator. The material of the second heat exchange element 30 can be aluminum or copper, or other materials with high thermal conductivity, to ensure that the second heat exchange element 30 has good thermal conductivity. The side of the second heat exchange element 30 closest to the first heat exchange element 20 serves as the second cavity 70, while the side of the second heat exchange element 30 farther from the first heat exchange element 20 serves as the heat source.

[0057] In a possible implementation, a surface of the second heat exchange element 30 away from the first heat exchange element 20 is provided with a plurality of spaced third heat exchange fins 31 , and a surface of the second heat exchange element 30 close to the first heat exchange element 20 is flat.

[0058] It should be noted that by providing a plurality of spaced third heat exchange fins 31 on the side of the second heat exchange element 30 away from the first heat exchange element 20, the heat exchange area between the second heat exchange element 30 and the heat source can be increased, and the plurality of third heat exchange fins 31 can be evenly spaced, thereby improving the heat exchange efficiency of the second heat exchange element 30. By providing a flat surface on the side of the second heat exchange element 30 that is closer to the first heat exchange element 20, not only is the installation difficulty between the second heat exchange element 30 and the housing 10 reduced, but the sealing performance between the second heat exchange element 30 and the housing 10 is also improved.

[0059] In another possible implementation, a side of the second heat exchange element 30 away from the first heat exchange element 20 is provided with multiple spaced third heat exchange fins 31 , and a side of the second heat exchange element 30 close to the first heat exchange element 20 is provided with multiple spaced third heat exchange fins 31 .

[0060] It should be noted that by arranging third heat exchange fins 31 on both the side of the second heat exchange element 30 away from the first heat exchange element 20 and the side close to the first heat exchange element 20, the heat exchange area between the second heat exchange element 30 and the heat source can be increased, and the heat exchange area between the second heat exchange element 30 and the working medium in the second cavity 70 can also be increased.

[0061] In another possible implementation, a surface of the second heat exchange element 30 away from the first heat exchange element 20 is a plane, and a surface of the second heat exchange element 30 close to the first heat exchange element 20 is provided with a plurality of third heat exchange fins 31 distributed at intervals.

[0062] It should be noted that by configuring the surface of the second heat exchange element 30 facing away from the first heat exchange element 20 as a flat surface, the second heat exchange element 30 has a smooth outer surface, thereby preventing dust accumulation. By providing a plurality of spaced third heat exchange fins 31 on the surface of the second heat exchange element 30 facing the first heat exchange element 20, the heat exchange area between the second heat exchange element 30 and the working medium in the second cavity 70 can be increased.

[0063] In another possible implementation, a surface of the second heat exchange element 30 away from the first heat exchange element 20 is a plane, and a surface of the second heat exchange element 30 close to the first heat exchange element 20 is a plane.

[0064] It should be noted that by configuring the surface of the second heat exchanger 30 facing away from the first heat exchanger 20 as a flat surface, the second heat exchanger 30 has a smooth outer surface, thereby preventing dust accumulation. By configuring the surface of the second heat exchanger 30 facing the first heat exchanger 20 as a flat surface, not only is the installation of the second heat exchanger 30 and the housing 10 simplified, but the sealing performance between the second heat exchanger 30 and the housing 10 is also improved.

[0065] As a feasible embodiment, the first resonance component 40 includes a drive component, a first elastic member 41 and a piston 42. The first end of the drive component is connected to the inner wall surface of the shell 10, the second end of the drive component is connected to the piston 42, the first elastic member 41 is connected between the drive component and the piston 42, and the drive component is used to drive the piston 42 to move back and forth between the first heat exchange component 20 and the drive component.

[0066] It should be noted that the elastic force of the first elastic member 41 and the mass of the piston 42 constitute a first resonant system. The driving assembly drives the piston 42 to move back and forth between the first heat exchange member 20 and the driving assembly, alternately compressing and expanding the working medium in the first cavity 60, thereby forming a highly efficient pressure wave generation process. Figure 2 As shown, the first end of the drive assembly can be the bottom surface of the drive assembly, and the inner wall surface of the housing 10 can be the bottom wall of the housing 10. The second end of the drive assembly can be the side surface of the drive assembly in the horizontal direction. When the side surface of the drive assembly is connected to the piston 42, the stability of the movement of the piston 42 can be improved.

[0067] Among them, one end of the first elastic member 41 is fixedly connected to the drive assembly, and the other end is fixedly connected to the piston 42. Two first elastic members 41 can be provided, and the two first elastic members 41 are symmetrically arranged between the drive assembly and the piston 42 relative to the central axis of the shell 10. Exemplarily, the first elastic member 41 can be one of a steel winding spring, a leaf spring, a magnetic spring and a gas spring. The drive assembly can be detachably connected to the shell 10. Exemplarily, the drive assembly and the shell 10 can be connected by screws, and can also be connected by a clamping structure. Among them, the clamping structure can include a clamping head provided on one of the drive assembly and the shell 10, and a clamping slot provided on the other of the drive assembly and the shell 10, and the clamping head is clamped in the clamping slot.

[0068] As a feasible embodiment, the drive assembly includes an electromagnetic driver 43, a stator assembly 44 and an electromagnetic driver 45. The electromagnetic driver 43 is connected to the shell 10, the stator assembly 44 is arranged inside the electromagnetic driver 43, and the electromagnetic driver 45 is located outside the electromagnetic driver 43 and connected to the piston 42. The stator assembly 44 includes a silicon steel sheet and a coil, and the coil is arranged on the silicon steel sheet.

[0069] It should be noted that the electromagnetic driver 43 drives the electromagnetic driver 45 to reciprocate vertically, driving the piston 42 to reciprocate between the first heat exchanger 20 and the driver assembly, thereby causing the first resonant assembly 40 to resonate, thereby forming a pressure wave within the first cavity 60. In one possible implementation, the stator assembly 44 is disposed within the electromagnetic driver 43, and the electromagnetic driver 45 is disposed outside the electromagnetic driver 43 and is detachably connected to the piston 42. The electromagnetic driver 45 and the piston 42 move synchronously.

[0070] The electromagnetic driver 43 can transmit power to the electromagnetic driver 45 in a non-contact manner, such as by generating an electromagnetic force through an electromagnetic field. Alternatively, the electromagnetic driver 43 can transmit power to the electromagnetic driver 45 through contact. For example, a connecting component can be provided between the electromagnetic driver 43 and the electromagnetic driver 45. For example, the connecting component can be an electric cylinder, and power transmission is achieved by extending and retracting the output end of the electric cylinder. The electromagnetic driver 43 can be any form of electromagnetic linear mechanism. For example, the electromagnetic driver 43 can be a reciprocating drive device comprising a permanent magnet linear oscillating motor, a reluctance linear motor, or a rotary motor with a crankshaft device attached.

[0071] As a feasible embodiment, the second resonant assembly 50 includes a regenerator 51, a second elastic member 52, and an ejector 53. The ejector 53 is connected to the inner wall of the housing 10 via the second elastic member 52, and the regenerator 51 is connected to the ejector 53. The regenerator 51 is filled with a porous material and has numerous densely distributed channels for the passage of the working medium.

[0072] It should be noted that the elastic force of the second elastic member 52 and the mass of the ejector 53 form a second resonant system. The second resonant assembly 50 resonates under the pressure waves of the first resonant assembly 40, thereby alternatingly compressing and expanding the working medium within the second cavity 70. The heat source outside the second heat exchanger 30 exchanges heat through the second heat exchanger 30, reducing the heat source's heat and increasing the heat of the working medium within the second cavity 70. In one possible implementation, the second elastic member 52 can be a steel coil spring, a leaf spring, a magnetic spring, or a gas spring.

[0073] When the second resonant component 50 resonates with the first resonant component 40, there is a certain phase difference between them, that is, there is a motion hysteresis phenomenon. This phase difference is used to ensure the normal operation of the Stirling cycle. The middle portion of the ejector 53 has a mounting hole, and the regenerator 51 is disposed within the mounting hole. The upper and lower end surfaces of the regenerator 51 are respectively flush with the upper and lower end surfaces of the ejector 53. The regenerator 51 and the ejector 53 constitute the ejector assembly. For example, the regenerator 51 and the ejector 53 can be connected by interference fit, clip connection, adhesive connection, etc.

[0074] In one possible implementation, the end face area of the ejector assembly close to the second heat exchanger 30 is not equal to the end face area of the ejector assembly away from the second heat exchanger 30. This arrangement can form forces of different sizes at both ends of the ejector assembly, thereby generating a force difference, and utilizing this force difference to achieve the desired motion phase (phase difference). Such an area relationship can make the stiffness of the second elastic member 52 connected to the ejector 53 smaller, which is beneficial to reducing system vibration. In another possible implementation, the end face area of the ejector assembly away from the second heat exchanger 30 is equal to the end face area of the ejector assembly close to the second heat exchanger 30, and the stiffness coefficient of the second elastic member 52 needs to be adjusted to meet the desired motion phase (phase difference). The regenerator 51 can be made of a porous material and is used to transfer the heat of the working medium in the second cavity 70 from one side (the second cavity 70) of the regenerator 51 to the other side (the second cavity 70).

[0075] It should also be noted that a stepped surface is provided on one side of the shell 10 near the second heat exchange element 30, and the second elastic member 52 is connected to the stepped surface and is arranged parallel to the central axis of the shell 10. This arrangement can reduce the adverse effects of the vibration of the second resonant component 50 on the shell 10, for example, reducing the vibration level of the shell 10. The shell 10 can be a one-piece shell 10 or a split shell 10. The split shell 10 can include a first shell 11 and a second shell 12, and the first shell 11 and the second shell 12 are detachably connected. For example, the first shell 11 and the second shell 12 can be connected by a bolt assembly or by a clamp assembly.

[0076] As a feasible implementation, the regenerator 51 is a columnar member, and the ratio of the axial length of the regenerator 51 to the radial length of the regenerator 51 is not greater than 0.5.

[0077] It should be noted that, referring to Figure 3As shown, the axial length of the regenerator 51 is represented by H1, and the radial length of the regenerator 51 is represented by D1. In one possible implementation, the regenerator 51 can be configured as a cylinder, and the ratio between the axial length and radial length of the regenerator 51 is set to be less than or equal to 0.5. In this case, the radial length of the regenerator 51 is equal to the cylinder diameter. This configuration shortens the axial heat transfer path of the regenerator 51, reduces heat loss, and thereby transfers more heat from the second cavity 70 to the first cavity 60. It also helps to reduce the ratio of the axial to radial dimensions of the free piston Stirling device, achieving a flatter structure, simplifying the structure within the free piston Stirling device, reducing the design and manufacturing difficulty of the free piston Stirling device, and improving economic performance. The ratio between the axial length and radial length of the regenerator 51 can be 0.1, 0.2, 0.3, 0.4, or 0.5, or any value less than or equal to 0.5. In actual use, the ratio between the axial length and radial length of the regenerator 51 can be selected as needed, and this embodiment is not limited here. In another possible implementation, the regenerator 51 can be configured as a regular polygonal prism, such as a regular hexagonal prism or a cube. The ratio of the axial length to the radial length of the regenerator 51 is less than or equal to 0.5. In this case, the radial length of the regenerator 51 is the vertical distance between two opposite sides of the regular polygonal prism. In actual use, the user can select the shape of the regenerator 51 as needed, and this embodiment is not limited thereto.

[0078] In a possible implementation, the first heat exchange element 20 is a tubular element or a plurality of tubular elements arranged in parallel, and the ratio of the axial length of the second heat exchange fins 22 to the axial length of the first heat exchange element 20 is not greater than 0.5.

[0079] It should be noted that, referring to Figure 2 and Figure 4As shown, the axial direction of the first heat exchanger 20 can be regarded as the radial direction of the shell 10, the axial length of the first heat exchanger 20 is represented by D2, and the axial length of the second heat exchange fin 22 is represented by H2. In one possible implementation, the first heat exchanger 20 can be set as a round tube or a square tube, and the ratio of the axial length of the second heat exchange fin 22 to the axial length of the first heat exchanger 20 is less than or equal to 0.5. Such an arrangement is conducive to reducing the ratio of the axial size to the radial size of the free piston Stirling device, achieving structural flatness, simplifying the structure within the free piston Stirling device, and thus reducing the design and processing difficulty of the free piston Stirling device, thereby improving economic performance. In another possible implementation, the first heat exchanger 20 can be set as a plurality of parallel round tubes or square tubes, and the ratio of the axial length of the second heat exchange fin 22 to the axial length of the first heat exchanger 20 is less than or equal to 0.5. Such an arrangement is also conducive to achieving structural flatness of the free piston Stirling device, simplifying the structure within the free piston Stirling device, thereby reducing the design and processing difficulty of the free piston Stirling device, and improving economic performance. Among them, the ratio of the axial length of the second heat exchange fin 22 to the axial length of the first heat exchange element 20 can be 0.1, 0.2, 0.3, 0.4 or 0.5, or any value less than or equal to 0.5. In actual use, the ratio of the axial length of the second heat exchange fin 22 to the axial length of the first heat exchange element 20 can be selected as needed, and this embodiment is not limited here.

[0080] In a possible implementation, the second heat exchange element 30 is a circular plate, and the ratio of the axial length of the second heat exchange element 30 to the diameter of the second heat exchange element 30 is not greater than 0.5.

[0081] It should be noted that, referring to Figure 5As shown, the axial length of the second heat exchanger 30 is represented by H3, and the diameter of the second heat exchanger 30 is represented by D3. In one possible implementation, the second heat exchanger 30 can be set as a circular plate, and the ratio of the axial length to the diameter of the second heat exchanger 30 is less than or equal to 0.5. This setting can shorten the heat movement path in the second heat exchanger 30, reduce heat loss, and speed up the transfer of heat from the heat source to the second cavity 70, thereby improving heat exchange efficiency. It is also beneficial to reduce the ratio of the axial size to the radial size of the free piston Stirling device, achieve structural flatness, simplify the structure within the free piston Stirling device, and thus reduce the design and processing difficulty of the free piston Stirling device and improve economic performance. Among them, the ratio of the axial length to the diameter of the second heat exchanger 30 can be 0.1, 0.2, 0.3, 0.4 or 0.5, and can also be any value less than or equal to 0.5. In actual use, the ratio of the axial length to the diameter of the second heat exchanger 30 can be selected as needed, and this embodiment is not limited here. In another possible implementation, the second heat exchange member 30 can be configured as a polygonal plate, such as a rectangular plate. In this case, the ratio of the axial length to the side length of the second heat exchange member 30 is less than or equal to 0.5. In actual use, the user can select the shape of the second heat exchange member 30 as needed, and this embodiment does not limit this.

[0082] As a feasible implementation, the regenerator 51 , the first heat exchange element 20 and the second heat exchange element 30 are arranged in parallel along the axial direction of the regenerator 51 .

[0083] It should be noted that arranging the regenerator 51, the first heat exchanger 20, and the second heat exchanger 30 in parallel along the axis of the regenerator 51 helps reduce the difficulty of installing the regenerator 51, the first heat exchanger 20, and the second heat exchanger 30. It also helps reduce the ratio of the axial dimension to the radial dimension of the free piston Stirling device, achieves a flatter structure, and improves economic performance. At the same time, this arrangement also allows the heat obtained from the heat source by the second heat exchanger 30 to flow along the central axis of the housing 10 over the shortest distance through the second heat exchanger 30, the second cavity 70, the regenerator 51, and the first heat exchanger 20 to achieve heat exchange, thereby achieving an optimal flow path and minimizing heat flow losses.

[0084] In a possible implementation, the central axis of the regenerator 51 coincides with the central axis of the second heat exchange element 30 .

[0085] It should be noted that by arranging the central axis of the heat regenerator 51 to coincide with the central axis of the second heat exchanger 30, the heat regenerator 51, the first heat exchanger 20 and the second heat exchanger 30 can be arranged opposite each other along the central axis direction of the shell 10, which can accelerate the speed of heat transfer along the central axis direction of the shell 10 and further improve the heat exchange efficiency.

[0086] As a feasible implementation, the pressure range of the working medium in the working chamber is 0.08-0.2 MPa.

[0087] It should be noted that by setting the pressure range of the working medium to 0.08-0.2MPa, that is, the working medium in the working chamber is not pressurized (atmospheric pressure) or is filled with low pressure. Such a setting can greatly reduce the sealing requirements and pressure resistance requirements of the free piston Stirling device, thereby greatly improving the range of selection of materials and processing technology of the free piston Stirling device, and further greatly improving the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat occasions. When the pressure of the working medium in the working chamber is greater than 0.2MPa, the sealing requirements and pressure resistance requirements will increase, the range of selection of materials and processing technology will be narrowed, and the economic efficiency of the free piston Stirling device in small temperature difference refrigeration or pump heat occasions will be reduced. Among them, the pressure range can be 0.08MPa, 0.1MPa, 0.12MPa, 0.15MPa, 0.18MPa or 0.2MPa, and can also be any value between 0.08-0.2MPa. In actual use, the user can select the pressure of the working medium according to needs, and this embodiment is not limited here.

[0088] As a feasible implementation, the working medium in the working chamber includes one or more of air, helium, hydrogen and nitrogen.

[0089] It should be noted that the working medium can be air, which is widely available, easily accessible, and pollution-free. The working medium can also be one of helium, hydrogen, and nitrogen. The working medium can also be a combination of air, helium, hydrogen, and nitrogen.

[0090] A refrigeration process that can be implemented in the free piston Stirling device provided in Example 1 of the present application is as follows:

[0091] Before the start of the cycle: define the first cavity 60 as the compression cavity, and the second cavity 70 as the expansion cavity. The working medium in the compression cavity and the expansion cavity are connected through the regenerator 51. Assuming that the device has good isothermal heat transfer capability, it can ensure that the working medium temperatures in the compression cavity and the expansion cavity remain constant (isothermal). Under steady-state working conditions, the regenerator 51 has established a stable temperature gradient from high temperature (expansion cavity) to low temperature (compression cavity). Define the end point of the stroke of the piston 42 and the ejector 53 close to the second heat exchanger 30 as the near end point, and the end point of the stroke away from the second heat exchanger 30 as the far end point. Define the initial position (the position at the beginning of the cycle) as the piston 42 at the far end point and the ejector 53 at the near end point.

[0092] After the cycle begins: the piston 42 moves from the far dead center to the equilibrium position, the displacer 53 remains stationary at the near dead center, the working medium pressure increases, the working medium in the compression chamber isothermally compressed and releases heat, and the heat is transferred to the outside through the first heat exchanger 20. When the working medium in the expansion chamber reaches the rated pressure, the piston continues to move from the equilibrium position to the near dead center, the displacer 53 begins to move toward the equilibrium position, and the working medium enters the expansion chamber through the regenerator 51. The regenerator 51 has good heat storage and heat transfer capabilities, and the temperature at each point along the way from the compression chamber to the expansion chamber remains stable. When the working medium passes through the regenerator 51, each point along the way releases heat at an isochoric rate. After the piston 42 reaches the near dead center, it remains stationary, and the displacer 53 continues to move toward the far dead center. The working medium in the expansion chamber expands and absorbs heat. During this process, the working medium in the expansion chamber isothermally absorbs heat from the second heat exchanger 30. When the displacer 53 reaches the far end point, it remains stationary there. The piston moves from the near end point toward the equilibrium position. The working medium in the expansion chamber further expands isothermally and absorbs heat isothermally from the second heat exchange element 30. Then, the displacer 53 moves from the far end point toward the equilibrium position, and the piston 42 continues to move from the equilibrium position toward the far end point. The displacer 53 and the piston 42 reach the equilibrium position and the far end point at the same time, respectively. During this process, the working medium that enters the expansion chamber from the expansion chamber returns to the compression chamber from the expansion chamber through the regenerator 51, while releasing heat at various points along the way in the regenerator 51. Then, the piston 42 remains stationary at the far end point, and the displacer 53 continues to move to the near end point. The remaining working medium in the expansion chamber continues to return to the compression chamber from the expansion chamber through the regenerator 51. The above process constitutes a complete cycle.

[0093] It should be noted that the above-mentioned refrigeration process is an operation process when the phase difference between the piston 42 and the displacer 53 is 180 degrees. It can be understood that the above-mentioned refrigeration process is a classic embodiment given for the convenience of describing the principle. The phase difference between the piston 42 and the displacer 53 can also be 120 degrees, 150 degrees, or other values. In actual use, the user can select the phase difference between the piston 42 and the displacer 53 as needed, and the embodiment of the present application is not limited. It should also be noted that in actual use, the piston 42 and the displacer 53 continue to move without any dwell time, and the phase difference between the two is preferably about 120 degrees.

[0094] Example 2

[0095] Figure 6 This is a schematic structural diagram of the free piston Stirling device provided in Example 2 of the present application.

[0096] Reference Figure 6 As shown, based on the first embodiment of the present application, the second embodiment of the present application provides a free piston Stirling device. Compared with the first embodiment of the present application, the difference between the second embodiment of the present application and the first embodiment of the present application is that the structure of the second resonant component 50 is different.

[0097] In the second embodiment of the present application, the second resonant component 50 includes a heat regenerator 51, a second elastic member 52 and a center rod 54. The outer peripheral surface of the heat regenerator 51 abuts against the inner wall surface of the shell 10. A mounting hole is opened in the middle of the heat regenerator 51. One end of the center rod 54 is set in the mounting hole, and the other end of the center rod 54 is connected to the inner bottom wall surface of the shell 10 through the second elastic member 52.

[0098] It should be noted that such an arrangement can simplify the structure of the second resonant component 50 and reduce the difficulty of installing the second resonant component 50 and the housing 10 .

[0099] As a feasible implementation, the top surface of the central rod 54 is flush with the top surface of the regenerator 51 .

[0100] It should be noted that such a setting can increase the connection area between the center rod 54 and the heat regenerator 51, improve the connection strength between the center rod 54 and the heat regenerator 51, and can also make the center rod 54 and the heat regenerator 51 have the same spacing with the bottom surface of the second heat exchanger 30 during the synchronous lifting process, which is beneficial to reducing the axial size of the whole machine and achieving flattening.

[0101] Compared with the first embodiment of the present application, the second embodiment of the present application also differs from the first embodiment in that the structures of the piston 42 , the electromagnetic driver 43 and the stator assembly 44 are different.

[0102] In the second embodiment of the present application, a mounting hole is opened in the middle of the piston 42 , and the center rod 54 passes through the mounting hole of the piston 42 and has a gap with the inner wall surface of the piston 42 .

[0103] As a feasible implementation, the axis of the regenerator 51 , the axis of the center rod 54 and the axis of the piston 42 coincide with each other.

[0104] It should be noted that such a setting is conducive to the heat obtained by the second heat exchanger 30 from the heat source flowing along the central axis direction of the shell 10, through the second heat exchanger 30, the second cavity 70, the heat regenerator 51, and the first heat exchanger 20 in sequence through the shortest distance to achieve heat exchange, thereby obtaining the best flow path and the minimum heat flow loss.

[0105] In one possible implementation, a plurality of electromagnetic drivers 43 and stator assemblies 44 are provided, and are evenly spaced along the circumferential direction of the housing 10. This arrangement facilitates the installation of the center rod 54. In another possible implementation, both the electromagnetic driver 43 and the stator assembly 44 are annular members, and the electromagnetic driver 43 and the stator assembly 44 are coaxially arranged. This arrangement facilitates the installation of the center rod 54.

[0106] Compared with the first embodiment of the present application, the second embodiment of the present application also differs from the first embodiment of the present application in that the structure of the first heat exchange element 20 is different.

[0107] In the second embodiment of the present application, one or more pairs of first heat exchange elements 20 are provided, and each pair of first heat exchange elements 20 are coaxially arranged and located on opposite sides of the central rod 54. The multiple pairs of first heat exchange elements 20 are arranged in parallel and installed at the same level.

[0108] It should be noted that such a configuration can prevent the center rod 54 from contacting the first heat exchange element 20 during movement and causing wear, thereby increasing the service life of the entire machine.

[0109] The other technical features of the second embodiment of the present application are the same as those of the first embodiment of the present application and can achieve the same technical effects, so they will not be described in detail here.

[0110] In the description of the embodiments of the present application, it should be understood that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. The orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In the description of this application, the meaning of "multiple" is two or more, unless otherwise precisely and specifically specified.

[0111] The terms "first," "second," "third," "fourth," and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products, or apparatus.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application 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 or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A free piston Stirling device, characterized in that: The heat exchanger comprises a shell, a first heat exchange element and a second heat exchange element, wherein the shell has a working chamber filled with a working medium, the first heat exchange element is arranged in the working chamber, and the second heat exchange element is arranged at an opening of the shell and blocks the working chamber; A first resonant component and a second resonant component connected to the shell are provided in the working chamber, the first resonant component is located on a side of the first heat exchange element away from the second heat exchange element, and the second resonant component is located between the first heat exchange element and the second heat exchange element; A first cavity is formed between the first resonant component and the second resonant component, the first heat exchange element is located in the first cavity, and a second cavity is formed between the second resonant component and the second heat exchange element; The second resonant component is provided with a channel connecting the first cavity and the second cavity, and the shell is provided with a mounting hole connecting the working cavity and the outside of the shell, and at least part of the first heat exchange member extends to the outside of the shell through the mounting hole.

2. The free piston Stirling device according to claim 1, characterized in that The first heat exchange member is a tubular member. The first heat exchange member located in the working chamber is provided with first heat exchange fins, and the first heat exchange member located outside the working chamber is provided with second heat exchange fins.

3. The free piston Stirling device according to claim 1, wherein: The second heat exchange element is a plate-shaped element; The second heat exchange element is provided with a plurality of third heat exchange fins distributed at intervals on a side away from the first heat exchange element, and the side of the second heat exchange element close to the first heat exchange element is a plane; Alternatively, a plurality of third heat exchange fins distributed at intervals are provided on a side of the second heat exchange element away from the first heat exchange element, and a plurality of third heat exchange fins distributed at intervals are provided on a side of the second heat exchange element close to the first heat exchange element; Alternatively, a surface of the second heat exchange element away from the first heat exchange element is a plane, and a surface of the second heat exchange element close to the first heat exchange element is provided with a plurality of third heat exchange fins distributed at intervals; Alternatively, a surface of the second heat exchange element away from the first heat exchange element is a plane, and a surface of the second heat exchange element close to the first heat exchange element is a plane.

4. The free piston Stirling device according to claim 1, wherein: The first resonant component includes a driving component, a first elastic member and a piston. The first end of the driving component is connected to the inner wall surface of the shell, the second end of the driving component is connected to the piston, the first elastic member is connected between the driving component and the piston, and the driving component is used to drive the piston to reciprocate between the first heat exchange component and the driving component.

5. The free piston Stirling device according to claim 4, characterized in that The driving assembly includes an electromagnetic driver, a stator assembly and an electromagnetic driver, wherein the electromagnetic driver is connected to the housing, the stator assembly is arranged inside the electromagnetic driver, and the electromagnetic driver is located outside the electromagnetic driver and connected to the piston; The stator assembly includes silicon steel sheets and coils, and the coils are arranged on the silicon steel sheets.

6. The free piston Stirling device according to claim 1, wherein: The second resonance component includes a regenerator, a second elastic member, and an ejector. The ejector is connected to the inner wall surface of the shell through the second elastic member, and the regenerator is connected to the ejector.

7. The free piston Stirling device according to claim 6, characterized in that The regenerator is a columnar member, and the ratio of the axial length of the regenerator to the radial length of the regenerator is not greater than 0.

5.

8. The free piston Stirling device according to claim 6, wherein: Along the axial direction of the regenerator, the regenerator, the first heat exchange element and the second heat exchange element are arranged in parallel; And / or, the central axis of the heat regenerator coincides with the central axis of the second heat exchange element.

9. The free piston Stirling device according to any one of claims 1 to 8, characterized in that The pressure range of the working medium in the working chamber is 0.08-0.2 MPa.

10. The free piston Stirling device according to any one of claims 1 to 8, characterized in that The working medium in the working chamber includes one or more of air, helium, hydrogen and nitrogen.

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