A dynamic stirling generator piston air tightness test method and computer medium

Abstract

The application discloses a kind of dynamic stirling generator piston air tightness test method and computer medium, method includes: in the connecting place of power piston and motor mobile connection frame same plate spring connecting frame and power piston, sealing ring is arranged;Plate spring connecting frame is replaced by the plate spring connecting frame with central through-hole;Loosen screw so that the power piston plate spring of stirling generator and support frame are in the state of fine adjustment;Sealed gas supply is supplied to stirling generator by through-hole;Adjust supply pressure to preset test gas pressure, drive power piston to carry out preset reciprocating motion in cylinder;Fine adjustment power piston plate spring position, when gas flow is stable, lock all screws;Adjust supply pressure to working gas pressure, when gas flow is stable and lower than preset value, record as static leakage value;Drive power piston to carry out working state reciprocating motion in cylinder, when motion is stable, record gas total flow value;Subtract static leakage value from gas total flow value, obtain net dynamic leakage rate.

Description

Technical Field

[0001] This invention relates to the field of Stirling generators, and more particularly to a method for testing the piston airtightness of a dynamic Stirling generator and a computer medium. Background Technology

[0002] The superior performance of a free-piston Stirling generator relies heavily on the long-term, complete sealing of its internal closed-loop working fluid (such as helium). As the core moving component, the piston-cylinder assembly's dynamic airtightness directly determines the generator's efficiency and lifespan. Leakage during operation will cause a drop in working fluid pressure, leading to a significant decrease in output power, reduced overall efficiency, and in severe cases, even generator failure. This "operating leakage," caused by dynamic factors under actual operating conditions, is a major failure risk that is difficult to predict through static assembly testing.

[0003] Currently, the mainstream verification method for the airtightness of Stirling pistons in the industry is still the static pressure decay method. The static pressure decay method involves filling the sealed cavity with high-pressure gas while the generator is completely stationary, and indirectly evaluating the sealing performance by monitoring the rate of pressure drop over a specified time. However, the test conditions of the static pressure decay method are fundamentally disconnected from the actual working conditions of the piston: it cannot reproduce the complex dynamic environment caused by the high-speed reciprocating motion of the piston, and cannot truly reflect the actual leakage behavior of the piston seal gap under dynamic motion. Furthermore, the static pressure decay method can only quantitatively detect leakage under static conditions, lacking the ability to continuously and quantitatively measure the leakage rate under dynamic conditions. This evaluation mode, disconnected from actual operating conditions, not only hinders the efficiency of design iteration and optimization during the R&D phase, but also significantly increases the overall life-cycle maintenance costs and the risk of unexpected failures due to the inability to implement predictive maintenance during the maintenance phase.

[0004] Therefore, a new technical solution is urgently needed to address the technical problem of how to conduct dynamic Stirling generator piston airtightness testing. Summary of the Invention

[0005] This invention provides a method and computer medium for testing the air tightness of a dynamic Stirling generator piston, thereby solving the technical problem of how to conduct air tightness testing of a dynamic Stirling generator piston.

[0006] To achieve the above objectives, the present invention provides a method for testing the piston airtightness of a dynamic Stirling generator, comprising: A sealing ring is installed at the connection between the power piston and the motor mover connecting frame and the leaf spring connecting frame and the power piston; the leaf spring connecting frame is replaced with a leaf spring connecting frame with a through hole in the center; the screws are loosened to put the power piston leaf spring and the support frame of the Stirling generator in a fine-adjustable state; air is supplied to the Stirling generator seal through the through hole; Adjust the gas supply pressure to the preset test gas pressure, and drive the power piston to perform a preset reciprocating motion in the cylinder; fine-tune the position of the power piston plate spring, and tighten all screws when the gas flow is stable; adjust the gas supply pressure to the Stirling generator working gas pressure, and record the static leakage value when the gas flow is stable and lower than the preset value; drive the power piston to perform a working reciprocating motion in the cylinder, and record the total gas flow value when the motion is stable; subtract the static leakage value from the total gas flow value to obtain the net dynamic leakage rate.

[0007] Preferably, the driving piston performs a preset reciprocating motion within the cylinder, including: An external programmable power supply is used to apply a first AC excitation to the linear motor actuator to drive the power piston to perform a preset reciprocating motion in the cylinder; the first AC excitation includes frequency and amplitude parameters within a preset range; wherein the frequency range is 15Hz to 30Hz and the amplitude range is 5V to 15V.

[0008] Preferably, the static leakage value is defined as when the gas flow rate is stable and lower than a preset value, including: When the gas flow rate is stable, determine whether the gas flow rate is lower than the preset value; Stable gas flow rate is defined as: gas flow rate fluctuation within 30 seconds of continuous monitoring is less than or equal to ±5%; If the gas flow rate is not lower than the preset value at this time, it indicates that there is an abnormal external leak. Check the Stirling generator and eliminate the abnormal external leak. Then check again whether the gas flow rate is lower than the preset value. If the gas flow rate is lower than the preset value at this time, it indicates that there is no abnormal external leakage point of the Stirling generator. The gas flow rate at this time is recorded as the static leakage value of the Stirling generator.

[0009] Preferably, the reciprocating motion of the driving piston within the cylinder during operation includes: A second AC excitation is applied to the linear motor actuator by an external programmable power supply to drive the power piston to perform a preset reciprocating motion in the cylinder; the second AC excitation includes the frequency and amplitude parameters of the Stirling generator when it is in a preset working state, wherein the frequency ranges from 35Hz to 50Hz and the amplitude ranges from 20V to 35V.

[0010] Preferably, when the gas flow rate is stable, tightening all screws includes: When tightening all screws, ensure that the sealing rings achieve a seal and that the position of the power piston plate spring no longer moves.

[0011] Preferred options also include: When installing a sealing ring at the connection between the power piston and the motor mover connecting frame and the leaf spring connecting frame and the power piston, replace the power piston and motor mover connecting frame with O-ring grooves at both the upper and lower connection points, and place the sealing ring in the O-ring groove.

[0012] Preferably, supplying gas to the Stirling generator seal through the through-hole includes: An external gas supply system is used to supply sealed gas to the Stirling generator through a through-hole; the external gas supply system includes an air pump, a flow meter, and a pressure regulator; the air pump is used for filling the generator; the flow meter is used to monitor the gas flow rate; and the pressure regulator is used to adjust the filling gas pressure.

[0013] The present invention also provides a computer medium having computer program instructions stored thereon, which can be executed by a processor to implement the method of the present invention.

[0014] The present invention has the following beneficial effects: This invention presents a dynamic Stirling generator piston airtightness testing method that replicates the actual operating dynamics of the piston through controllable reciprocating motion. Adjustable electrical parameters simulate the generator's full operating conditions, overcoming the core defect of traditional static testing methods that distort operating conditions. This method accurately reflects the piston's dynamic leakage behavior. A constant-pressure gas supply path is constructed using a leaf spring connecting frame with through holes, allowing for real-time continuous gas flow measurement. The net dynamic leakage rate is accurately obtained by subtracting static leakage values, overcoming the inherent limitation of traditional static pressure decay methods in achieving continuous and accurate measurement of leakage rates under dynamic operating conditions. This enables precise quantitative evaluation of piston clearance sealing performance. This method can quickly assess the impact of different designs on dynamic sealing performance during the R&D phase, shortening the design iteration cycle. The output quantitative data can also support seal life prediction, enabling predictive maintenance and effectively reducing the overall machine's lifespan maintenance costs and failure risks.

[0015] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the method flow of a preferred embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a leaf spring connecting frame with a central through hole according to a preferred embodiment of the present invention.

[0018] Figure 3 This is a cross-sectional view of a leaf spring connecting frame with a central through hole according to a preferred embodiment of the present invention.

[0019] Figure 4 This is a top view of the power piston and motor mover connection bracket with O-shaped grooves according to a preferred embodiment of the present invention.

[0020] Figure 5 This is a cross-sectional view of the power piston and motor mover connection frame with O-shaped grooves according to a preferred embodiment of the present invention.

[0021] Figure 6 This is a simplified schematic diagram of a Stirling generator in the test state according to a preferred embodiment of the present invention.

[0022] In the attached diagram: 1. Cylinder; 2. Power piston; 3. Linear motor stator; 4. Linear motor mover; 5. Second replacement part; 6. First replacement part; 7. Power piston leaf spring; 8. Support frame; 9. Through hole; 10. O-ring groove. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0024] See Figure 1 In a preferred embodiment of the present invention, a method for testing the airtightness of a dynamic Stirling generator piston is provided, comprising: S1. Install a sealing ring at the connection between the power piston and the motor mover connecting frame and the leaf spring connecting frame and the power piston; replace the leaf spring connecting frame with a leaf spring connecting frame with a through hole in the center; loosen the screws to put the power piston leaf spring and the support frame of the Stirling generator in a fine-adjustable state; supply air to the Stirling generator seal through the through hole.

[0025] In a preferred embodiment of the present invention, when a sealing ring is provided at the connection between the power piston and the motor mover connecting frame and the plate spring connecting frame and the power piston, the power piston and motor mover connecting frame can be replaced with a power piston and motor mover connecting frame with O-ring grooves at both the upper and lower connection points, and the sealing ring is provided in the O-ring groove.

[0026] In a preferred embodiment of the present invention, the leaf spring connecting bracket with a central through hole is shown below. Figures 2 to 3 The main body of the connecting frame is a ring-shaped structure. Except for the through hole 9 in the center, it is consistent with the structure of a traditional leaf spring connecting frame and can be manufactured with reference to the specific Stirling generator to be tested. The connecting frame has a through hole 9 in the center, which is a through threaded hole, serving as an air passage interface.

[0027] In a preferred embodiment of the present invention, the power piston and motor mover connection frame, both with O-shaped grooves 10 at the upper and lower joints, are shown in the figure. Figures 4 to 5 Except for the O-rings 10 at both the upper and lower connections, the structure is consistent with the traditional power piston and motor mover connection frame, and can be manufactured with reference to the specific Stirling generator to be tested. The O-rings 10 are used to ensure the sealing reliability of the connection interface under high-pressure testing environment, so as to further prevent internal gas leakage.

[0028] In a preferred embodiment of the present invention, supplying gas to the Stirling generator seal through a through-hole includes: An external gas supply system supplies sealed gas to the Stirling generator through through-hole 9; the external gas supply system includes an air pump, a flow meter, and a pressure regulator; the air pump is used for air filling; the flow meter is used to monitor the gas flow rate; and the pressure regulator is used to adjust the air filling pressure.

[0029] In a preferred embodiment of the present invention, a schematic diagram of the Stirling generator in the test state is shown below. Figure 6 The original components of the Stirling generator include a cylinder 1, a power piston 2, a linear motor stator 3, a linear motor mover 4, a power piston leaf spring 7, and a support frame 8; the support frame 8 is used to fix the Stirling generator; the first replacement part 6 is a leaf spring connecting frame with a central through hole 9 in this embodiment; the second replacement part 5 is a power piston and motor mover connecting frame with O-ring grooves 10 at both the upper and lower connection points in this embodiment; the through hole 9 is used to connect to an external air supply system.

[0030] In a preferred embodiment of the present invention, the Stirling generator is mounted on the test platform via a support frame 8, and the axis of the test platform is strictly aligned with the axis of motion of the power piston.

[0031] S2. Adjust the air supply pressure to the preset test air pressure, and drive the power piston to perform a preset reciprocating motion in the cylinder; fine-tune the position of the power piston plate spring, and tighten all screws when the gas flow is stable.

[0032] In a preferred embodiment of the present invention, the preset test pressure range is 0.2 MPa to 0.3 MPa.

[0033] In a preferred embodiment of the present invention, driving the power piston to perform a preset reciprocating motion within the cylinder includes: An external programmable power supply is used to apply a first AC excitation to the linear motor actuator to drive the power piston to perform a preset reciprocating motion in the cylinder; the first AC excitation includes frequency and amplitude parameters within a preset range; wherein the frequency range is 15Hz to 30Hz and the amplitude range is 5V to 15V.

[0034] In a preferred embodiment of the present invention, tightening all screws when the gas flow rate is stable includes: When tightening all screws, ensure that the sealing rings achieve a seal and that the position of the power piston plate spring no longer moves.

[0035] S3. Adjust the gas supply pressure to the working gas pressure of the Stirling generator. When the gas flow rate is stable and lower than the preset value, record it as the static leakage value. Drive the power piston to perform reciprocating motion in the cylinder. When the motion is stable, record the total gas flow rate. Subtract the static leakage value from the total gas flow rate to obtain the net dynamic leakage rate.

[0036] In a preferred embodiment of the present invention, the static leakage value is defined as when the gas flow rate is stable and lower than a preset value, including: When the gas flow rate is stable, determine whether the gas flow rate is lower than the preset value; Stable gas flow rate includes: gas flow rate fluctuations of less than or equal to ±5% within 30 seconds of continuous monitoring.

[0037] If the gas flow rate is not lower than the preset value at this time, it indicates that there is an abnormal external leak. Check the Stirling generator and eliminate the abnormal external leak. Then check again whether the gas flow rate is lower than the preset value.

[0038] If the gas flow rate is lower than the preset value at this time, it indicates that there is no abnormal external leakage point of the Stirling generator. The gas flow rate at this time is recorded as the static leakage value of the Stirling generator.

[0039] In a preferred embodiment of the present invention, driving the power piston to reciprocate within the cylinder in a working state includes: A second AC excitation is applied to the linear motor actuator by an external programmable power supply to drive the power piston to perform a preset reciprocating motion in the cylinder; the second AC excitation includes the frequency and amplitude parameters of the Stirling generator when it is in a preset working state, wherein the frequency ranges from 35Hz to 50Hz and the amplitude ranges from 20V to 35V.

[0040] In a preferred embodiment of the present invention, by adjusting the electrical parameters of the programmable power supply, different load and speed conditions can be simulated, thereby enabling testing under different conditions.

[0041] This invention presents a dynamic Stirling generator piston airtightness testing method that replicates the actual operating dynamics of the piston through controllable reciprocating motion. Adjustable electrical parameters simulate the generator's full operating conditions, overcoming the core defect of traditional static testing methods that distort operating conditions. This method accurately reflects the piston's dynamic leakage behavior. A constant-pressure gas supply path is constructed using a leaf spring connecting frame with through holes, allowing for real-time continuous gas flow measurement. The net dynamic leakage rate is accurately obtained by subtracting static leakage values, overcoming the inherent limitation of traditional static pressure decay methods in achieving continuous and accurate measurement of leakage rates under dynamic operating conditions. This enables precise quantitative evaluation of piston clearance sealing performance. This method can quickly assess the impact of different designs on dynamic sealing performance during the R&D phase, shortening the design iteration cycle. The output quantitative data can also support seal life prediction, enabling predictive maintenance and effectively reducing the overall machine's lifespan maintenance costs and failure risks.

[0042] In a preferred embodiment of the present invention, a computer medium is also provided, on which computer program instructions are stored, which can be executed by a processor to implement the method of the present invention.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the airtightness of a piston in a dynamic Stirling generator, characterized in that, include: A sealing ring is installed at the connection between the power piston and the motor mover connecting frame and the leaf spring connecting frame and the power piston; the leaf spring connecting frame is replaced with a leaf spring connecting frame with a through hole in the center; the screws are loosened to put the power piston leaf spring and the support frame of the Stirling generator in a fine-adjustable state; air is supplied to the Stirling generator through the through hole; Adjust the air supply pressure to the preset test air pressure, and drive the power piston to perform a preset reciprocating motion in the cylinder; Fine-tune the position of the power piston plate spring, and tighten all screws when the gas flow is stable; adjust the gas supply pressure to the working gas pressure of the Stirling generator, and record the static leakage value when the gas flow is stable and lower than the preset value; drive the power piston to perform working reciprocating motion in the cylinder, and record the total gas flow value when the motion is stable; subtract the static leakage value from the total gas flow value to obtain the net dynamic leakage rate.

2. The method for testing the piston airtightness of a dynamic Stirling generator according to claim 1, characterized in that, The driving piston performs a preset reciprocating motion within the cylinder, including: An external programmable power supply is used to apply a first AC excitation to the linear motor actuator to drive the power piston to perform a preset reciprocating motion in the cylinder; the first AC excitation includes frequency and amplitude parameters within a preset range; wherein the frequency range is 15Hz to 30Hz and the amplitude range is 5V to 15V.

3. The method for testing the piston airtightness of a dynamic Stirling generator according to claim 2, characterized in that, When the gas flow rate is stable and lower than a preset value, it is recorded as a static leakage value, including: When the gas flow rate is stable, determine whether the gas flow rate is lower than the preset value; The gas flow rate stability includes: within 30 seconds of continuous monitoring, the gas flow rate fluctuation is less than or equal to ±5%; If the gas flow rate is not lower than the preset value at this time, it indicates that there is an abnormal external leak. Check the Stirling generator and eliminate the abnormal external leak. Then check again whether the gas flow rate is lower than the preset value. If the gas flow rate is lower than the preset value at this time, it indicates that there is no abnormal external leakage point of the Stirling generator. The gas flow rate at this time is recorded as the static leakage value of the Stirling generator.

4. The method for testing the piston airtightness of a dynamic Stirling generator according to claim 3, characterized in that, The reciprocating motion of the driving piston within the cylinder includes: A second AC excitation is applied to the linear motor actuator by an external programmable power supply to drive the power piston to perform a preset reciprocating motion in the cylinder; the second AC excitation includes the frequency and amplitude parameters of the Stirling generator when it is in a preset working state, wherein the frequency ranges from 35Hz to 50Hz and the amplitude ranges from 20V to 35V.

5. The method for testing the piston air tightness of a dynamic Stirling generator according to claim 4, characterized in that, Tighten all screws, including: when the gas flow rate is stable. When all screws are tightened, ensure that the sealing ring achieves a seal and that the position of the power piston plate spring no longer moves.

6. The method for testing the piston airtightness of a dynamic Stirling generator according to claim 5, characterized in that, Also includes: When a sealing ring is installed at the connection between the power piston and the motor mover connecting frame and the plate spring connecting frame and the power piston, the power piston and motor mover connecting frame is replaced with a power piston and motor mover connecting frame with O-ring grooves at both the upper and lower connection points, and the sealing ring is placed in the O-ring groove.

7. The method for testing the piston airtightness of a dynamic Stirling generator according to claim 6, characterized in that, Supplying gas to the Stirling generator seal through the through-hole includes: An external gas supply system supplies sealed gas to the Stirling generator through the through-hole; the external gas supply system includes an air pump, a flow meter, and a pressure regulator; the air pump is used for air filling; the flow meter is used for monitoring the gas flow rate; and the pressure regulator is used for adjusting the air filling pressure.

8. A computer medium, characterized in that, It stores computer program instructions that can be executed by a processor to implement the method as described in any one of claims 1 to 7.

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