Damping measuring device and method for expansion machine

Abstract

The embodiment of the invention relates to the field of expansion machines, and discloses an expansion machine damping measuring device and method, and the device comprises a starting module which is used for applying an acting force to a moving end of a moving mechanism of an expansion machine, and the direction of the acting force is the moving direction of the moving end when the expansion machine works normally; when the moving end moves to a limit position, the acting force applied to the moving end is removed, so that the moving end reciprocates along the moving direction under the action of the elastic component; the measuring module is used for generating a displacement curve of the moving end in the reciprocating motion process of the moving end; and the calculation module is used for calculating the damping of the expansion machine according to the amplitude of the adjacent wave crests in the displacement curve. And the damping of the expansion machine can be accurately measured.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of expanders, and particularly to an expander damping measurement device and method. Background Art

[0002] Compared with the traditional integral rotary refrigerator, the split Stirling refrigerator has the advantages of long service life and low vibration. The split Stirling refrigerator includes a compressor and a pneumatically driven expander. The compressor and the pneumatically driven expander are connected by a flexible transmission pipeline. And the key factor to solve the frequency matching problem between the compressor and the expander is the damping of the expander. Therefore, how to measure the damping of the expander is an urgent problem to be solved in the process of frequency matching between the compressor and the expander. Summary of the Invention

[0003] The purpose of the present invention is to provide at least one expander damping measurement device, which can at least solve the technical problem of how to measure the damping of the expander, and can at least achieve the technical effect of accurately measuring the damping of the expander.

[0004] To solve the above technical problem, at least one embodiment of the present application provides an expander damping measurement device. The expander includes a motion mechanism, and the motion mechanism includes a moving part and an elastic part. The elastic part is used to reset the position of the moving end of the moving part. The expander damping measurement device includes:

[0005] A starting module, configured to apply a force to the moving end, and the direction of the force is the moving direction of the moving end when the expander is working normally; and when the moving end moves to the limit position, the force applied to the moving end is removed, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic part;

[0006] A measuring module, configured to generate a displacement curve of the moving end during the reciprocating motion;

[0007] A calculating module, configured to calculate the damping of the expander according to the amplitudes of adjacent wave peaks in the displacement curve.

[0008] In some optional embodiments, the starting module includes:

[0009] A coil bobbin, the interior of which is hollow, and the coil bobbin is fixedly connected to the housing of the expander;

[0010] An extension rod, which is located inside the coil bobbin, and one end of the extension rod is connected to the moving end;

[0011] A first coil, wound around the extension rod;

[0012] A second coil, wound around the coil bobbin;

[0013] A first power supply unit, configured to supply direct current to the first coil and the second coil, so that the interaction between the magnetic field generated by the first coil and the magnetic field generated by the second coil forms the acting force. When the moving end moves to the limit position, the supply of direct current to the first coil and the second coil is stopped, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic member.

[0014] In some alternative embodiments, the measurement module includes:

[0015] A primary coil, wound around the coil bobbin;

[0016] A secondary coil, including a first secondary coil and a second secondary coil. The first secondary coil and the second secondary coil are respectively located on both sides of the primary coil, and are both wound around the coil bobbin, and the distance between the first secondary coil and the primary coil is equal to the distance between the second secondary coil and the primary coil;

[0017] A magnetic core, fixedly arranged on the extension rod;

[0018] A second power supply unit, configured to supply direct current to the primary coil when the moving component moves to the limit position;

[0019] A measurement unit, configured to measure the potential difference between the first secondary coil and the second secondary coil during the reciprocating motion of the moving component, and use the curve of the potential difference versus time as the displacement curve.

[0020] In some alternative embodiments, the measurement module includes:

[0021] A laser displacement sensor, configured to collect the displacement of the extension rod;

[0022] A generation unit, configured to generate the displacement curve according to the collected displacement of the extension rod.

[0023] In some alternative embodiments, when calculating the damping of the expander according to the amplitudes of adjacent wave peaks in the displacement curve, the following calculation formula is used:

[0024]

[0025] Wherein, δ = lnA 1 −lnA 2 ;

[0026] Wherein, c is the damping of the expander; ξ is the damping ratio of the vibration system, and the vibration system includes the motion mechanism, the extension rod, the magnetic core, and the first coil; m is the mass of the vibration system; k is the stiffness of the vibration system; δ is the logarithmic decrement, and A 1 and A 2 are respectively the amplitudes of adjacent wave peaks in the displacement curve.

[0027] In some alternative embodiments, the expander damping measuring device further includes:

[0028] a temperature regulation module for regulating the ambient temperature of the hot end of the expander.

[0029] In some alternative embodiments, the temperature regulation module includes:

[0030] an annular cavity sleeved on the hot end of the expander, and an inlet and an outlet are provided on the annular cavity;

[0031] a flow regulating valve for regulating the flow rate of the coolant input into the annular cavity to regulate the ambient temperature of the hot end of the expander.

[0032] In some alternative embodiments, the annular cavity is bonded to the hot end of the expander through a heat-conducting adhesive.

[0033] In some alternative embodiments, the material of the annular cavity is made of oxygen-free copper.

[0034] At least one embodiment of the present application further provides an expander damping measurement method, which is applied to the expander damping test device as described above. The expander includes a motion mechanism, and the motion mechanism includes a moving part and an elastic part. The elastic part is used to reset the position of the moving end of the moving part. The expander damping measurement method includes:

[0035] Apply a force to the moving end, and the direction of the force is the moving direction of the moving end when the expander is working normally; and when the moving end moves to the limit position, remove the force applied to the moving end so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic part;

[0036] Generate a displacement curve of the moving end during the reciprocating motion;

[0037] Calculate the damping of the expander according to the amplitudes of adjacent wave peaks in the displacement curve.

[0038] At least one embodiment of the present application further provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the above-mentioned expander damping measurement method.

[0039] At least one embodiment of the present application further provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the above-mentioned expander damping measurement method is implemented.

[0040] The expander damping measurement device and method provided by the embodiment of the present application apply a force to the moving end of the moving part of the expander through a starting module, and the direction of the force is the moving direction of the moving end when the expander is working normally; and when the moving end moves to the limit position, the force applied to the moving end is removed, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic member; during the reciprocating motion of the moving end, a displacement curve of the moving end during the reciprocating motion is generated by a measuring module; finally, a damping calculation module calculates the damping of the expander according to the amplitudes of adjacent wave peaks in the displacement curve. Thus, the damping of the expander can be accurately measured. Description of the Drawings

[0041] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplary illustrations do not constitute a limitation on the embodiments.

[0042] Figure 1 is a structural block diagram of an expander damping measurement device;

[0043] Figure 2 is a structural schematic diagram of an expander damping measurement device;

[0044] Figure 3 is a schematic diagram of the measured displacement curve;

[0045] Figure 4 is another structural schematic diagram of an expander damping measurement device;

[0046] Figure 5 is a flowchart of an expander damping measurement method;

[0047] Figure 6 is another flowchart of an expander damping measurement method. Detailed Embodiments

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will elaborate on each embodiment of this application in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in each embodiment of this application, many technical details are presented to help readers better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can still be implemented. The division of the following embodiments is for convenience of description and should not constitute any limitation to the specific implementation of this application. The various embodiments can be combined and cross-referenced with each other on the premise of not being contradictory.

[0049] To facilitate the understanding of the embodiments of this application, the relevant content about the expander will be introduced here first.

[0050] Compared with traditional integral rotary refrigerators, the split Stirling refrigerator has the advantages of long life and low vibration. The split Stirling refrigerator includes a compressor and a pneumatically driven expander. The compressor and the pneumatically driven expander are connected by a flexible transmission pipeline. And the key factor in solving the frequency matching problem between the compressor and the expander is the damping of the expander. Therefore, how to measure the damping of the expander is an urgent problem to be solved in the process of frequency matching between the compressor and the expander.

[0051] To solve the above technical problem of how to measure the damping of the expander, the present invention proposes an expander damping measurement device. The following will specifically describe the implementation details of the expander damping measurement device in this embodiment. The following content is only the implementation details provided for convenience of understanding and is not necessary for implementing this solution.

[0052] Embodiment 1:

[0053] This embodiment provides an expander damping measurement device for measuring the damping of an expander. The expander includes a motion mechanism, and the motion mechanism includes a moving part and an elastic part. The elastic part is used to reset the position of the moving end of the moving part. The moving part includes the part that participates in the work of the expander to expand and depressurize by using compressed gas.

[0054] As Figure 1 shown, the expander damping measurement device includes a starting module 111, a measuring module 112, and a calculating module 113.

[0055] The starting module 111 is used to apply a force to the moving end, and the direction of the force is the moving direction of the moving end when the expander is working normally; and when the moving end moves to the limit position, the force applied to the moving end is removed, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic part.

[0056] Specifically, the starting module 111 moves the moving end of the expander to any one of the extreme positions on both sides of the moving direction to prepare for the reciprocating motion of the moving end.

[0057] The measuring module 112 is used to generate the displacement curve of the moving end during the reciprocating motion of the moving end.

[0058] Specifically, during the reciprocating motion of the moving end, the vibration of the moving end decays with time, and the displacement curve refers to the curve of the vibration of the moving end decaying with time during the reciprocating motion of the moving end.

[0059] The calculating module 113 is used to calculate the damping of the expander according to the amplitudes of adjacent wave peaks in the displacement curve.

[0060] Specifically, the reasoning process of the calculation formula for the damping of the expander is as follows:

[0061] The amplitudes of adjacent wave peaks in the displacement curve are A 1 、A 2 , and the time between the adjacent wave peaks is T. Then where ω n is the natural frequency of the vibration system, and the vibration system includes all components participating in the reciprocating motion.

[0062] Let δ be the logarithmic decrement.

[0063] It can be obtained that ξ is the damping ratio of the vibration system.

[0064] Since c is the damping of the expander, it can be obtained that

[0065] In summary, the calculation formula for the damping of the expander is:

[0066] where δ = lnA 1 -lnA 2 ;

[0067] In the formula, c is the damping of the expander; ξ is the damping ratio of the vibration system, and the vibration system refers to the components participating in the reciprocating motion; m is the mass of the vibration system; k is the stiffness of the vibration system; δ is the logarithmic decrement, and A 1 、A 2 are the amplitudes of adjacent wave peaks in the displacement curve respectively.

[0068] The expander damping measurement device provided in this embodiment applies a force to the moving end of the moving part of the expander through the starting module 111, and the direction of the force is the moving direction of the moving end when the expander is operating normally; and when the moving end moves to the limit position, the force applied to the moving end is removed, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic component; during the reciprocating motion of the moving end, the displacement curve of the moving end during the reciprocating motion is generated by the measurement module 112; finally, the damping of the expander is calculated by the calculation module 113 according to the amplitudes of adjacent wave peaks in the displacement curve. Thus, the damping of the expander can be accurately measured.

[0069] Embodiment 2:

[0070] This embodiment is a detailed description of the starting module of the above-mentioned expander damping measurement device. The expander includes a motion mechanism, and the motion mechanism includes a moving part and an elastic component, and the elastic component is used to reset the position of the moving end of the moving part. The moving part includes the components that participate in the expander's work of expanding and reducing pressure by using compressed gas. For example, in a piston expander, as Figure 2 shown, the expander includes a regenerator 1, a cold finger housing 2, an expansion piston 3, an expansion piston rod 16, an expander base 4, an air pipe 5, and a spring 6. Among them, the moving part includes the regenerator 1, the expansion piston 3, and the expansion piston rod 16. One end of the expansion piston rod 16 that is not connected to the expansion piston 3 is the moving end of the moving part. The elastic component refers to the spring 6.

[0071] As Figure 2 shown, the starting module includes a coil bobbin (not shown), an extension rod 15, a first coil 11, a second coil 12, and a first power supply unit (not shown).

[0072] The coil bobbin has a hollow interior, and the coil bobbin is fixedly connected to the housing of the expander, aiming to keep the coil bobbin in a state of relative rest with the expander; alternatively, a support frame can be provided separately to fix the position of the coil bobbin.

[0073] The extension rod 15 is located inside the coil bobbin, and one end of the extension rod 15 is connected to the moving end.

[0074] The first coil 11 is wound around the extension rod 15. To prevent the first coil 11 from falling off, the first coil 11 is also adhered to the extension rod 15.

[0075] The second coil 12 is wound around the coil bobbin. To prevent the second coil 12 from falling off, the second coil 12 and the coil bobbin can also be adhesively fixed, or a wire groove suitable for the size of the second coil 12 can be provided on the coil bobbin.

[0076] It should be noted that the number of turns, current direction, and current magnitude of the first coil 11 and the second coil 12 are not limited. As long as the first coil 11 and the second coil 12 are energized, the interaction between the magnetic field generated by the first coil 11 and the magnetic field generated by the second coil 12 can push the extension rod 15 so that the moving end moves in any direction along the moving direction.

[0077] The first power supply unit is used to provide direct current to the first coil 11 and the second coil 12, so that the interaction between the magnetic field generated by the first coil 11 and the magnetic field generated by the second coil 12 forms the acting force. When the moving end moves to the limit position, the supply of direct current to the first coil 11 and the second coil 12 is stopped, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic member.

[0078] Specifically, as shown in Figure 2 , a wiring plug 13 can be provided to supply direct current to the first coil 11 and the second coil 12.

[0079] During the measurement of the expander damping:

[0080] The starting module is fixedly installed with the expander to be measured, and the first coil 11 and the second coil 12 are connected to the wiring plug 13.

[0081] The first power supply unit is started to supply direct current to the first coil 11 and the second coil 12, so that the interaction between the magnetic field generated by the first coil 11 and the magnetic field generated by the second coil 12 forms the acting force. The acting force pushes the extension rod 15, so that the moving end fixedly connected to the extension rod 15 moves in any direction along the moving direction.

[0082] When the moving end moves to the limit position, the starting unit is stopped to stop supplying direct current to the first coil 11 and the second coil 12, so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic member. During this reciprocating motion, the extension rod 15 fixedly connected to the moving end and the first coil 11 wound around the extension rod 15 also move with the movement of the moving end.

[0083] Embodiment 3:

[0084] This embodiment provides a detailed description of the measurement module of the above-mentioned expander damping measurement device. Refer to Figure 2 , the measurement module includes a coil bobbin (not shown), an extension rod 15, a primary coil 8, a secondary coil, a magnetic core 10, a second power supply unit (not shown), and a measurement unit (not shown).

[0085] The coil bobbin has a hollow interior and is fixedly connected to the housing of the expander, aiming to keep the coil bobbin in a state of relative rest with respect to the expander; alternatively, a support frame can be provided separately to fix the position of the coil bobbin.

[0086] The extension rod 15 is located inside the coil bobbin, and one end of the extension rod 15 is connected to the moving end.

[0087] The primary coil 8 is wound around the coil bobbin.

[0088] The secondary coil includes a first secondary coil 7 and a second secondary coil 9. The first secondary coil 7 and the second secondary coil 9 are respectively located on both sides of the primary coil 8, are both wound around the coil bobbin, and the distance between the first secondary coil 7 and the primary coil 8 is equal to the distance between the second secondary coil 9 and the primary coil 8.

[0089] Among them, in order to prevent the primary coil 8, the first secondary coil 7, and the second secondary coil 9 from falling off, the primary coil 8, the first secondary coil 7, and the second secondary coil 9 can also be fixedly bonded to the coil bobbin with an adhesive, or wire grooves suitable for the sizes of the primary coil 8, the first secondary coil 7, and the second secondary coil 9 can be provided on the coil bobbin respectively.

[0090] The magnetic core 10 is fixedly provided on the extension rod 15. Preferably, the magnetic core 10 is bonded to the extension rod 15 with an adhesive, and the magnetic core 10 is made of pure iron for electrical engineering.

[0091] The second power supply unit is used to supply direct current to the primary coil 8 when the moving part moves to the limit position. Specifically, as Figure 3 shown, a wiring plug 13 is provided to supply direct current to the primary coil 8.

[0092] The measurement unit is used to measure the potential difference between the first secondary coil 7 and the second secondary coil 9 during the reciprocating movement of the moving part, and take the curve of the potential difference versus time as the displacement curve.

[0093] During the process of measuring the expander damping:

[0094] When the moving end moves to the extreme position, that is, when the starting module stops, the second power supply unit is started to supply direct current to the primary coil 8. The magnetic field generated by electromagnetic induction forms a closed loop through the magnetic core 10, the first secondary coil 7, and the second secondary coil 9. At this time, the second power supply unit is stopped. During the reciprocating movement of the moving end, the moving end drives the magnetic core 10 on the extension rod 15 to reciprocate. The reciprocating magnetic core 10 will induce different electromotive forces in the first secondary coil 7 and the second secondary coil 9. The difference between the electromotive forces of the first secondary coil 7 and the second secondary coil 9 can reflect the position of the moving end, that is, the curve of the difference between the electromotive forces of the first secondary coil 7 and the second secondary coil 9 with time is used as the displacement curve. The displacement curve is as Figure 3 shown.

[0095] Embodiment 4:

[0096] This embodiment is a detailed description of the measurement module of the expander damping measurement device described in Embodiment 1 or Embodiment 2. On the basis of Embodiment 1 or Embodiment 2, the measurement module includes a laser displacement sensor and a generating unit.

[0097] The laser displacement sensor is used to collect the displacement of the extension rod 15 or the moving end. Specifically, if the viewing angle of the movement trajectory of the extension rod 15 or the moving end is blocked, a windowing operation can be performed on the blocking object to expose the viewing angle for the laser displacement sensor to measure.

[0098] The generating unit is used to generate the displacement curve according to the collected displacement of the extension rod 15 or the moving end.

[0099] Embodiment 5:

[0100] This embodiment is a detailed description of the above-mentioned expander damping measurement device. On the basis of any of the above embodiments, the measurement module further includes a temperature adjustment module. The temperature adjustment module is used to adjust the ambient temperature of the hot end of the expander.

[0101] In some embodiments, as Figure 4 shown, the temperature adjustment module includes an annular cavity 14 and a flow regulating valve.

[0102] The annular cavity 14 is sleeved on the hot end of the expander, and the annular cavity 14 is provided with an inlet and an outlet. The hot end of the expander can be understood as the side where the expansion piston 3 and / or the regenerator 1 of the expander are located.

[0103] The flow regulating valve is used to regulate the flow rate of the coolant input into the annular cavity 14 to regulate the ambient temperature at the hot end of the expander. The coolant can be a liquid coolant or a gas coolant, without limitation. For example, the coolant can be liquid nitrogen.

[0104] Specifically, by regulating the flow rate of the coolant entering the annular cavity 14, the ambient temperature at the hot end of the expander is regulated, thereby regulating the temperature of the gas inside the hot end of the expander.

[0105] To reduce the thermal resistance, the annular cavity 14 and the hot end of the expander are bonded together with a thermally conductive adhesive. The annular cavity 14 is made of a material with better thermal conductivity, such as oxygen-free copper.

[0106] In the preparation stage of measuring the damping of the expander, the annular cavity 14 is sleeved on the hot end of the expander.

[0107] During the process of measuring the damping of the expander, liquid nitrogen is input into the annular cavity 14 through the opening of the annular cavity 14, where it evaporates and gasifies, thereby cooling the ambient temperature at the hot end of the expander, and further cooling the temperature of the gas inside the hot end of the expander. The gasified nitrogen is discharged from the outlet of the annular cavity 14. In this process, by adjusting the opening degree of the flow regulating valve, the flow rate of the liquid nitrogen entering the annular cavity 14 is controlled, thereby controlling the ambient temperature at the hot end of the expander, and further controlling the temperature of the gas inside the hot end of the expander. Thus, the damping of the expander at different temperatures can be tested. Since the temperature of the Stirling refrigerator operates near 77K, by using the temperature adjustment module to regulate the ambient temperature at the hot end of the expander to regulate the temperature of the gas inside the hot end of the expander, the damping of the expander at a low temperature near 77K at its hot end can be measured, which is meaningful in actual work.

[0108] Embodiment Six:

[0109] This embodiment provides an expander damping test method applied to the above-mentioned expander damping test device. The expander includes a motion mechanism, and the motion mechanism includes a moving component and an elastic component. The elastic component is used to reset the position of the moving end of the moving component. The moving component includes components that participate in the expander's work of expanding and reducing pressure using compressed gas. For example, in a piston expander, such as Figure 2 or Figure 4As shown, the expander includes a regenerator 1, a cold finger housing 2, an expansion piston 3, an expansion piston rod 16, an expander base 4, an air pipe 5, and a spring 6. Among them, the moving components include the regenerator 1, the expansion piston 3, and the expansion piston rod 16. One end of the expansion piston rod 16 that is not connected to the expansion piston 3 is the moving end of the moving components. The elastic component refers to the spring 6.

[0110] As Figure 5 shown, the method for measuring the damping of the expander includes:

[0111] Step S100: Apply a force to the moving end, and the direction of the force is the moving direction of the moving end when the expander is operating normally; and when the moving end moves to the limit position, remove the force applied to the moving end so that the moving end makes a reciprocating motion along the moving direction under the action of the elastic component.

[0112] Step S200: Generate a displacement curve of the moving end during the reciprocating motion of the moving end.

[0113] Step S300: Calculate the damping of the expander according to the amplitudes of adjacent wave peaks in the displacement curve.

[0114] In order to measure the damping of the expander at different temperatures, as Figure 6 shown, the method for measuring the damping of the expander further includes, before step S100: Step S400: Adjust the ambient temperature of the hot end of the expander.

[0115] It is worth mentioning that for the specific execution processes of the steps involved in this embodiment, reference can be made to the functions implemented by the structural devices specifically included in each of the foregoing functional modules, and details are not elaborated herein.

[0116] Embodiment Seven:

[0117] Another embodiment of the present application relates to an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for measuring the damping of the expander in the above embodiments.

[0118] Among them, the memory and the processor are connected in a bus manner. The bus can include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors and memories together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, etc., which are well known in the art, so they will not be further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a component or multiple components, such as multiple receivers and transmitters, and provides a unit for communicating with various other devices on the transmission medium. The data processed by the processor is transmitted on the wireless medium through the antenna. Further, the antenna also receives data and transmits the data to the processor.

[0119] The processor is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interface, voltage regulation, power management, and other control functions. The memory can be used to store the data used by the processor when executing operations.

[0120] Embodiment Eight:

[0121] Another embodiment of the present application relates to a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above method embodiments are implemented.

[0122] That is, those skilled in the art can understand that all or part of the steps in implementing the above method embodiments can be completed by a program instructing relevant hardware. The program is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM for short), random access memories (RAM for short), magnetic disks, or optical discs that can store program codes.

[0123] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present application, and in practical applications, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. An expander damping measuring device, characterized in that: The expander includes a motion mechanism, the motion mechanism includes a motion component and an elastic component, the elastic component is used to reset the position of the motion end of the motion component, and the expander damping measurement device includes: a start module, configured to apply a force to the moving end, the direction of the force being the moving direction of the moving end when the expander is working normally; and when the moving end moves to the limit position, removing the force applied to the moving end, so that the moving end reciprocates along the moving direction under the action of the elastic component; A measuring module, used for generating a displacement curve of the moving end during the reciprocating motion of the moving end; A calculation module is used to calculate the damping of the expander according to the amplitude of adjacent peaks in the displacement curve.

2. The expander damping measuring device according to claim 1, characterized in that: The startup module includes: A coil skeleton, wherein the interior of the coil skeleton is hollow and the coil skeleton is fixedly connected to the shell of the expander; An extension rod, the extension rod is located inside the coil skeleton, and one end of the extension rod is connected to the moving end; A first coil, wound on the extension rod; A second coil, wound on the coil frame; The first power supply unit is used to provide direct current to the first coil and the second coil so that the interaction between the magnetic field generated by the first coil and the magnetic field generated by the second coil forms the force, and when the moving end moves to the extreme position, the direct current is stopped from being provided to the first coil and the second coil so that the moving end reciprocates along the moving direction under the action of the elastic component.

3. The expander damping measuring device according to claim 2, characterized in that: The measuring module comprises: A primary coil is wound on the coil frame; The secondary coil comprises a first secondary coil and a second secondary coil, wherein the first secondary coil and the second secondary coil are respectively located on both sides of the primary coil and are both wound on the coil frame, and the spacing between the first secondary coil and the primary coil is equal to the spacing between the second secondary coil and the primary coil; A magnetic core, fixed on the extension rod; a second power supply unit, used for providing direct current to the primary coil when the moving component moves to an extreme position; The measuring unit is used to measure the potential difference between the first secondary coil and the second secondary coil when the moving part is performing reciprocating motion, and use the curve of the potential difference and time as the displacement curve.

4. The expander damping measuring device according to claim 2, characterized in that: The measuring module comprises: A laser displacement sensor, used for collecting the displacement of the extension rod; A generating unit is used to generate the displacement curve according to the collected displacement of the extension rod.

5. The expander damping measuring device according to claim 3, characterized in that: The damping of the expander is calculated according to the amplitude of adjacent peaks in the displacement curve, and the calculation formula used is as follows: in, δ=lnA1-lnA2; Wherein, c is the damping of the expander; ξ is the damping ratio of the vibration system, and the vibration system includes the motion mechanism, the extension rod, the magnetic core and the first coil; m is the mass of the vibration system; k is the stiffness of the vibration system; δ is the logarithmic attenuation rate, and A1 and A2 are the amplitudes of adjacent peaks in the displacement curve, respectively.

6. The expander damping measuring device according to any one of claims 1 to 5, characterized in that: The expander damping measuring device further comprises: The temperature regulating module is used to regulate the ambient temperature of the hot end of the expander.

7. The expander damping measuring device according to claim 6, characterized in that: The temperature regulating module comprises: An annular cavity, wherein the annular cavity is sleeved on the hot end of the expander, and an inlet and an outlet are provided on the annular cavity; The flow regulating valve is used to regulate the flow of the coolant input into the annular cavity so as to regulate the ambient temperature of the hot end of the expander.

8. The expander damping measuring device according to claim 7, characterized in that: The annular cavity is bonded to the hot end of the expander by heat-conducting adhesive.

9. The expander damping measuring device according to claim 7, characterized in that: The annular cavity is made of oxygen-free copper.

10. A method for measuring expander damping, characterized in that: Applied to the expander damping test device according to any one of claims 1 to 9, the expander includes a motion mechanism, the motion mechanism includes a motion component and an elastic component, the elastic component is used to reset the position of the motion end of the motion component, and the expander damping measurement method includes: Applying a force to the moving end, the direction of the force being the moving direction of the moving end when the expander is working normally; and when the moving end moves to the limit position, removing the force applied to the moving end, so that the moving end reciprocates along the moving direction under the action of the elastic component; generating a displacement curve of the moving end during the reciprocating motion of the moving end; The damping of the expander is calculated according to the amplitudes of adjacent peaks in the displacement curve.

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