Polar region low-temperature valve sealing performance testing system and method based on multi-physics field coupling

Abstract

The invention provides a polar region low-temperature valve sealing performance testing system and method based on multi-physics field coupling, and belongs to the technical field of polar region environment equipment reliability testing. According to the invention, the sealing performance of the valve in a low-temperature environment is quantitatively evaluated by simulating polar extreme climate conditions and combining a multi-physical field coupling test technology. According to the invention, multiple environmental stresses such as polar region low temperature, temperature circulation, pressure fluctuation and surface icing can be accurately simulated, and a high-precision sensing technology and comprehensive data analysis are integrated, so that comprehensive and quantitative evaluation and life prediction of the sealing performance of the valve from a static boundary to dynamic degradation and from a macroscopic phenomenon to a micromechanism are realized; and an effective technical means is provided for reliability design and verification of key valves of polar equipment.

Description

Technical Field

[0001] This invention belongs to the field of reliability testing technology for polar environment equipment, and relates to a polar cryogenic valve sealing performance testing system and method based on multi-physics field coupling, and particularly to a comprehensive testing method for the dynamic sealing performance of electromagnetic valves applied in polar cryogenic environments. Background Technology

[0002] As the core actuators of fluid control systems, valves' sealing performance directly determines the system's reliability, energy efficiency, and safety. In polar environments, valves face extreme temperature gradients ranging from -70°C to 0°C, drastic temperature fluctuations with diurnal temperature variations of up to 50°C, and the combined effects of high humidity and strong ultraviolet radiation. Existing research indicates that low-temperature environments induce a glass transition in sealing materials, causing the Shore hardness of commonly used sealing materials such as nitrile rubber to surge from 70A at room temperature to 90A at -40°C, with the elastic modulus increasing by three orders of magnitude. This results in uneven stress distribution on the sealing surface. Simultaneously, the difference in the linear expansion coefficients between the metal valve body and the sealing material (e.g., the α value for stainless steel and fluororubber is 17 × 10⁻⁶) further exacerbates the problem. -6 / ℃ and 80×10 -6 At -60℃, a radial shrinkage difference of 0.15mm will occur, causing the sealing gap to exceed the design tolerance range.

[0003] Current internationally accepted standards for sealing performance testing (such as ISO 5208-2015 and API 598-2016) are all based on ambient temperature (23±2℃) conditions and mainly employ traditional testing methods such as the bubble method and pressure drop method. These methods have three main technical bottlenecks: First, they cannot simulate the phase change process of media in polar environments (e.g., the precipitation of ice crystals in water at -10℃ will change the flow field characteristics); second, they lack quantitative analysis of the microscale contact behavior of the sealing interface (existing methods have a resolution of only millimeters, while actual leakage channels may be less than 10μm); and third, they do not consider the impact of temperature cyclic loads on the fatigue life of sealing materials (typical polar equipment needs to withstand 3-5 temperature change cycles per day).

[0004] According to statistics from the Polar Research Institute of China, approximately 32% of malfunctions in my country's polar research equipment originate from valve sealing failures, with 68% of these failures caused by low-temperature environments. While some researchers have conducted studies on low-temperature sealing—for example, Harbin Institute of Technology proposed a low-temperature leak detection method based on acoustic emission technology—its detection sensitivity is significantly affected by environmental noise. The German company Festo developed a -40℃ low-temperature testing platform, but it can only perform static sealing tests and cannot simulate dynamic operating conditions. Therefore, there is an urgent need to establish a dynamic testing system encompassing the coupling of multiple physical fields, including temperature, pressure, and flow fields, to overcome the technical bottlenecks of traditional testing methods and provide a scientific basis for the independent research and development of key valve components for polar equipment.

[0005] In summary, existing valve sealing performance testing methods face three major technical bottlenecks that urgently need to be overcome: First, the temperature control range of traditional testing platforms is limited to -40℃ to 50℃, which cannot cover extreme low-temperature environments in polar regions (-70℃ to 0℃); second, the testing parameters are limited and lack the ability to simulate complex environmental factors such as temperature cycling loads (e.g., 3-5 temperature change shocks per day) and medium phase change effects (e.g., ice crystal precipitation in water at -10℃); third, the detection methods have insufficient resolution, making it difficult to capture microscale leakage (below 10μm) at the sealing interface and the evolution of material fatigue damage. Summary of the Invention

[0006] This invention aims to address the shortcomings of existing valve sealing performance testing methods in terms of low-temperature adaptability testing, and provides a reliable method for evaluating valve sealing performance under low-temperature conditions. This invention uses simulated extreme polar climate conditions combined with multi-physics coupling testing technology to quantitatively evaluate the sealing performance of valves under low-temperature environments. This invention is applicable to the sealing performance testing of solenoid valves used in special scenarios such as fluid transport systems in polar research stations, hydraulic control systems of polar icebreakers, and energy supply systems for unmanned polar equipment. It is particularly suitable for evaluating the dynamic sealing performance of solenoid valves subjected to fluid pressures from 0.1 MPa to 10 MPa within a temperature range of -70℃ to 0℃. The technical solution of this invention can solve the following problems: (1) quantitative characterization of the viscoelastic behavior of sealing materials under ultra-low temperature conditions; (2) the failure mechanism of thermomechanical coupling at the interface between the valve body and the sealing component; (3) the influence of the low-temperature medium phase change process on leakage characteristics; and (4) the construction of a predictive model for sealing performance degradation under multi-physics coupling conditions.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A polar cryogenic valve sealing performance testing system based on multiphysics coupling is disclosed. The system comprises an environmental simulation subsystem, a multi-axis loading and measurement subsystem, and a central control and data processing subsystem. Details are as follows:

[0009] The environmental simulation subsystem provides a controllable low-temperature and complex environment, including a low-temperature environment simulation chamber, a complex refrigeration unit, and a spray icing device, with the low-temperature environment simulation chamber being its core. Specifically:

[0010] Low-temperature environment simulation chamber: The interior of the chamber forms the main test chamber, which is used to house the valve under test and some load measurement components. The chamber wall adopts a composite structure of polyurethane foam insulation layer (thickness ≥100mm) and inner wall surface electric heating anti-condensation membrane. The chamber door adopts double silicone rubber sealing strips to ensure heat insulation and airtightness.

[0011] The combined refrigeration unit integrates a liquid nitrogen pre-cooling circuit with a cascade compressor refrigeration cycle into the environmental simulation chamber. This unit can reduce the temperature of the main test chamber from room temperature to -70℃ at a rate of ≤10℃ / min, and stabilize it at any temperature point within the range of -70℃ to 0℃, with a temperature uniformity of ≤±2℃.

[0012] Spray icing device: This includes an array of spray nozzles, water supply pipelines, and a cryogenic water circulation unit located inside the chamber. This device can spray cold water at a temperature not exceeding 2°C onto the surface of the valve under test and designated areas to simulate polar droplet freezing conditions.

[0013] The multi-axis loading and measurement subsystem is installed inside the main test chamber of the environmental simulation chamber and acts directly on the valve under test. It includes a valve mounting and support assembly, a hydraulic servo loading unit, and a multi-sensor fusion detection array composed of a micro-leakage detection unit, a deformation and temperature monitoring unit, and an electrical performance monitoring unit. Specifically:

[0014] Valve mounting and support assembly: Constructed of an adjustable high-strength alloy steel bracket, used to fix the valve under test (such as an electro-hydraulic remote control valve assembly) and ensure its alignment with the test pipeline.

[0015] Hydraulic servo loading unit: Composed of a high-pressure pump driven by a servo motor, an accumulator, a precision proportional pressure valve, and piping, it is connected to the inlet and outlet of the valve under test. This unit can apply static pressure or dynamic alternating pressure (waveform and frequency programmable) from 0.1 MPa to 16 MPa.

[0016] Micro-leakage detection unit: Employs a high-precision mass flow meter, directly connected in series in the leakage collection pipeline downstream of the valve, to quantitatively measure the flow rate of the leaking medium, with a detection limit of 0.1 mL / h.

[0017] Deformation and temperature monitoring unit: includes multiple contact thermometers (attached to key parts such as valve body and valve seat) and non-contact laser displacement sensors (aligned with valve stem or actuator piston rod) to monitor temperature distribution and mechanical deformation at low temperatures.

[0018] Electrical performance monitoring unit: integrates an insulation resistance tester (500V DC) and a clamp meter to monitor the insulation resistance and operating current changes of the valve drive motor at low temperatures.

[0019] The central control and data processing subsystem coordinates and controls the entire testing process and processes data. It includes an industrial control computer, a multi-channel data acquisition card, and dedicated measurement and control software. The software implements programmed temperature curve and pressure spectrum loading control, and synchronously acquires, stores, and displays all sensor data. It also includes built-in data analysis and report generation algorithms.

[0020] A method for testing the sealing performance of cryogenic valves based on multi-physics coupling, the method being implemented using the aforementioned cryogenic valve sealing performance testing system, includes the following steps:

[0021] Step 1: System preparation and initial benchmark testing, establishing performance test benchmarks and confirming system status. Specifically:

[0022] Step 1.1: Install the valve under test onto the valve mounting and support assembly, and connect its drive line to the pipeline of the hydraulic servo loading unit. Close the environmental simulation chamber door and perform a sealing check on the pipeline system at room temperature (20±5℃).

[0023] Step 1.2: Activate the hydraulic servo loading unit to apply the rated working pressure to the valve. Control the valve to complete several opening-closing cycles, while using the micro-leakage detection unit to measure and record its baseline leakage rate at room temperature and rated pressure. Use the deformation and temperature monitoring unit to record the initial dimensional data of key components to obtain the room temperature baseline leakage rate and initial dimensions.

[0024] Step 2: Static low-temperature sealing performance spectrum test, used to obtain the sealing performance matrix of the valve under different steady-state low temperature and pressure combinations. Specifically:

[0025] Step 2.1: Start the composite refrigeration unit and lower the temperature of the main test chamber to the first target low temperature point T1 (e.g., -10℃) at a rate of no more than 10℃ / min, and maintain it for at least 6 hours to make the valve temperature uniform and stable.

[0026] Step 2.2: After the temperature T1 stabilizes, multiple static pressure points (e.g., 0.5MPa, 2MPa, 5MPa, 8MPa) are sequentially applied to the valve via the hydraulic servo loading unit. For each pressure point, the valve performs one switching action and then closes to maintain the pressure. After the pressure stabilizes, the steady-state leakage rate under this operating condition is measured using the micro-leakage detection unit.

[0027] Step 2.3: Repeat the above steps, and set the temperature of the main test chamber to other target low temperature points T2, T3...Tn (e.g. -30℃, -40℃, -50℃) in sequence, and complete the leakage rate test at all corresponding pressure points to obtain the static performance matrix.

[0028] Step 3: Dynamic environmental cycling and coupled stress testing, used to evaluate the cumulative and instantaneous effects of dynamic environmental stresses such as temperature cycling and icing on sealing performance. Specifically:

[0029] Step 3.1, Dynamic Temperature-Pressure Cyclic Test. Select a critical low temperature point (e.g., -30°C). At this temperature, control the hydraulic servo loading unit to make the system pressure fluctuate sinusoidally at a low frequency (e.g., 0.05Hz) between the minimum allowable pressure (e.g., 1MPa) and the maximum allowable pressure (e.g., 4MPa), continuously performing N cycles (e.g., 50 cycles). Throughout the entire cycle, use the micro-leakage detection unit to continuously monitor and record the transient changes in the leakage rate. This step yields the result: a dynamic leakage curve.

[0030] Step 3.2, External Spray Icing Test. Stabilize the temperature of the main test chamber at another test point (e.g., -10℃). Activate the spray icing device to periodically spray water onto the outer surface of the valve until the ice layer thickness is ≥5mm. Subsequently, without using additional heating, manually break the ice and immediately operate the valve to complete the opening and closing action. Record whether the valve operates normally after the ice-breaking operation, and use the micro-leakage detection unit to measure the leakage rate after the icing-breaking process. This step yields the results: functional status and leakage rate under icing conditions.

[0031] Step 4: Data Comprehensive Analysis and Performance Evaluation. The baseline leakage rate obtained in Step 1, the static performance matrix obtained in Step 2, and the dynamic leakage curve and post-icing leakage rate obtained in Step 3 are input into the central control and data processing subsystem for comprehensive processing and decision-making of the test results. Specifically:

[0032] Step 4.1 First, analyze the static performance matrix, plot the three-dimensional response surface of leakage rate as a function of temperature and pressure, and identify the critical degradation temperature point of sealing performance (for example, find the temperature corresponding to the sharp increase in leakage rate).

[0033] Step 4.2 Next, the dynamic leakage curve is analyzed to extract the trend of leakage rate increasing with the number of cycles, fit the performance degradation curve, and quantify the fatigue effect.

[0034] Step 4.3 Finally, synthesize all the data and conduct a comparative analysis. For example, calculate the growth rate of leakage rate at each low temperature point relative to the normal temperature baseline; analyze the correlation between excessive leakage rate at the critical temperature point (e.g., -40℃) and changes in material low-temperature hardness and sealing gap.

[0035] Step 4.4, Failure Mechanism Diagnosis and Life Prediction. Based on the above analysis results, the main modes of seal failure are diagnosed. Using the performance degradation curves and the accelerated life test model, the seal life of the valve under target polar cryogenic conditions is predicted.

[0036] Step 4.5: Generate Evaluation Report. A comprehensive performance evaluation report is automatically generated, including all raw data, analytical charts (such as performance surfaces and degradation curves), failure mechanism diagnosis, life prediction, and conformity determination.

[0037] This invention overcomes the five major technical limitations of traditional testing methods, and its beneficial effects are as follows:

[0038] (1) The temperature range extends to -70℃~0℃, covering the extreme low temperature environment in the Antarctic interior;

[0039] (2) The detection sensitivity has been improved to 0.01 mL / h, which can identify nanoscale defects at the sealing interface;

[0040] (3) To realize multi-stress coupling testing of temperature cycling, pressure alternation, and medium phase change;

[0041] (4) Establish a prediction model for sealing performance degradation with a prediction accuracy of ±15%;

[0042] (5) Testing efficiency is increased by 3 times, and the full performance test cycle of a single valve is shortened to 72 hours.

[0043] In summary, this invention establishes an in-situ testing system in the laboratory to accurately simulate multiple environmental stresses such as polar low temperatures, temperature cycles, pressure fluctuations, and surface icing. By integrating high-precision sensing technology and comprehensive data analysis, it achieves a comprehensive and quantitative assessment and life prediction of valve sealing performance, from static boundaries to dynamic degradation, and from macroscopic phenomena to microscopic mechanisms. This provides an effective technical means for the reliability design and verification of key valve components in polar equipment. In other words, this invention can be directly used to guide the optimization of the sealing structure of cryogenic solenoid valves. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of a polar cryogenic valve sealing performance testing system.

[0045] Figure 2 This is a flowchart of the valve body testing process.

[0046] In the diagram, 1 is the solenoid valve under test; 2 is the high-pressure liquid chamber; 3 is the insulated pipeline; 4 is the pressure control valve; 5 is the valve body support frame; 6 is the low-temperature environment laboratory; 7 is the anti-magnetic wire; 8 is the high-definition camera; 9 is the leakage measuring instrument; 10 is the liquid storage tank; and 11 is the power supply. Detailed Implementation

[0047] The specific embodiments of the present invention will be described in detail below with reference to the technical solution and flowchart of the present invention.

[0048] The structure of a polar cryogenic valve sealing performance testing system based on multiphysics coupling in this embodiment is as follows: Figure 1 As shown, the system consists of an environmental simulation subsystem, a multi-axis loading and measurement subsystem, and a central control and data processing subsystem. The specific components in the figure are as follows: valve under test 1 (taking an electro-hydraulic remote control valve assembly as an example), high-pressure liquid chamber 2, insulated pipeline 3, pressure control valve 4, valve body support frame 5, low-temperature environment simulation chamber 6 (i.e., low-temperature environment laboratory), anti-magnetic wire 7, high-definition camera 8, leakage measuring instrument 9, liquid storage tank 10, and power supply 11.

[0049] The environmental simulation subsystem is used to provide a controllable low-temperature and complex environment, including a low-temperature environment simulation chamber, a complex refrigeration unit, and a spray icing device. Its core is... Figure 1 The cryogenic environment simulation chamber 6 shown. Specifically:

[0050] In this embodiment, the low-temperature environment simulation chamber 6 has a welded steel structure, which forms the main test chamber. Its effective dimensions are 1.8 meters long, 1.2 meters wide, and 1.2 meters high. The chamber walls are made of a 120 mm thick closed-cell polyurethane high-pressure foam insulation layer with a thermal conductivity of less than 0.022 watts per meter Kelvin. The inner wall surface is fully covered with an active anti-condensation electric heating film. The chamber door is equipped with double silicone rubber sealing strips that can withstand temperatures as low as -70 degrees Celsius.

[0051] In this embodiment, the composite refrigeration unit is integrated into the chamber using a combination of open-loop liquid nitrogen injection precooling and a two-stage cascade compressor refrigeration system. This unit can reduce the temperature of the main test chamber from room temperature to -70 degrees Celsius at a rate not exceeding 10 degrees Celsius per minute, and within the range of -70 degrees Celsius to 0 degrees Celsius, achieve a temperature control accuracy better than ±1.5 degrees Celsius and a temperature uniformity not exceeding ±2 degrees Celsius.

[0052] In this embodiment, the spray icing device includes a stainless steel atomizing nozzle array, a precision peristaltic pump, and an external low-temperature constant-temperature circulating water tank located inside the chamber. This device provides cooling water with a stable temperature of 1.0 ± 0.5 degrees Celsius and automatically sprays according to a preset program.

[0053] The multi-axis loading and measurement subsystem is installed inside the main test chamber of the environmental simulation chamber and acts directly on the valve under test. It includes a valve mounting and support assembly, a hydraulic servo loading unit, and a multi-sensor fusion detection array composed of a micro-leakage detection unit, a deformation and temperature monitoring unit, and an electrical performance monitoring unit. Specifically:

[0054] In this embodiment, the valve mounting and support assembly: namely Figure 1 The valve body support frame 5 is a rigid frame welded from 304 stainless steel square tubing and equipped with a three-dimensional adjustable mounting plate to ensure that the installation and alignment accuracy error of the valve 1 under test is less than 0.5 mm.

[0055] In this embodiment, the hydraulic servo loading unit consists of: Figure 1 The system consists of a high-pressure liquid chamber 2, a pressure control valve 4, a liquid storage tank 10, and related pipelines. Driven by a servo motor, the system has a maximum output pressure of 21 MPa and a pressure control accuracy of ±0.2% of full scale. It can achieve static pressure maintenance and dynamic pressure loading with frequencies not exceeding 0.5 Hz, such as sine waves and triangular waves.

[0056] In this embodiment, the micro-leakage detection unit: namely Figure 1 The leakage measuring instrument 9 in this embodiment uses a Coriolis mass flow meter with a range of 0 to 100 grams per hour and an accuracy of ±0.1% of the reading. It is connected in series with the insulated pipe 3 in the closed leakage medium recovery pipe downstream of the valve to be tested.

[0057] In this embodiment, the deformation and temperature monitoring unit consists of multiple T-type thermocouples arranged in the valve body and actuator housing; simultaneously, a laser triangular displacement sensor with a resolution of 0.1 micrometers is used to perform non-contact measurement by aligning it with the piston rod end face of the valve actuator.

[0058] In this embodiment, the electrical performance monitoring unit integrates a digital megohmmeter and a clamp-on current sensor, which are connected by a magnetically shielded wire (7) to monitor the insulation resistance and operating current of the drive motor online.

[0059] In this embodiment, the visual monitoring unit is: Figure 1 The high-definition camera 8 is placed near the key sealing parts of the valve body for visual observation and recording of macroscopic phenomena such as leakage and icing.

[0060] The central control and data processing subsystem adopts a distributed architecture based on industrial computers and programmable logic controllers. The host computer measurement and control software is responsible for the programmed control of all actuators and the synchronous acquisition and processing of multi-channel data.

[0061] This embodiment also provides a method for testing the sealing performance of cryogenic valves based on multiphysics coupling. The procedure of this method is as follows: Figure 2 As shown, the steps for using the aforementioned testing system are as follows:

[0062] Step 1: System preparation and initial benchmark testing, specifically:

[0063] like Figure 2 As shown at the start of the process, install the valve under test on the support frame and connect all pipes and lines. Close the hatch and check the system's airtightness at room temperature. Subsequently, apply the rated operating pressure to the valve and control it to complete several opening and closing cycles. Measure and record the room temperature baseline leakage rate using a leakage meter, and record the initial position of the piston rod using a laser displacement sensor.

[0064] Supplementary data and results analysis: In this embodiment, the leakage rate was measured to be 0.08 ml / h at room temperature, and the initial position of the piston rod was recorded as the baseline zero point. This result indicates that the valve has good sealing performance at room temperature, establishing a reliable benchmark for subsequent low-temperature performance comparisons.

[0065] Step 2: Static low-temperature sealing performance spectrum test, specifically:

[0066] The temperature of the cryogenic environment simulation chamber is controlled to gradually decrease to multiple preset low-temperature points. After stabilization at each temperature point, multiple static pressure points are sequentially applied via a hydraulic servo loading unit. For each set of temperature-pressure conditions, the valves are activated and pressure is maintained, the steady-state leakage rate is measured, and the piston rod displacement is recorded.

[0067] Supplementary Data and Results Analysis: The tests yielded a static performance matrix. For example, at -10°C and 10 MPa, the leakage rate was measured to be 0.12 ml / h, with the piston rod shrinking by 25 micrometers relative to the room temperature baseline. At -30°C and 10 MPa, the leakage rate increased to 0.20 ml / h, with the piston rod shrinking by 68 micrometers. At -40°C and 10 MPa, the leakage rate increased sharply to 0.85 ml / h, exceeding the preset allowable threshold of 0.5 ml / h, while the piston rod shrinkage reached 112 micrometers. Data analysis indicates that the sealing performance significantly degrades near -40°C, and the piston rod shrinkage quantitatively reveals the cold contraction effect of metallic materials at low temperatures, which is correlated with the leakage rate increase trend.

[0068] Step 3: Dynamic Cyclic and Icing Coupling Test. This step includes two sub-stages, such as... Figure 2 The loops and conditional statements in the process. Specifically:

[0069] Dynamic temperature-pressure cycle test: The chamber temperature was stabilized at -30 degrees Celsius. The pressure was controlled to fluctuate sinusoidally at a frequency of 0.05 Hz between 3 MPa and 9 MPa, and this was repeated 50 times. Transient changes in the leakage rate were continuously monitored throughout the process.

[0070] Supplementary data and results analysis: Dynamic leakage curves were obtained. Analysis showed that the peak leakage rate increased from 0.22 ml / h in the first cycle to 0.35 ml / h in the 50th cycle. This reveals that under constant low temperature, alternating pressure loads caused a cumulative fatigue effect on the sealing surface, resulting in a gradual degradation of performance.

[0071] External spray icing test: Stabilize the chamber temperature at -10 degrees Celsius. Activate the spray device to form an ice layer at least 5 mm thick on the outer surface of the valve components. After manually breaking the ice, operate the valves and test their function and leakage rate.

[0072] Supplementary data and results analysis: The valve operated normally after ice breaking. After ice breaking, the leakage rate was measured to be 0.15 ml / h at a pressure of 5 MPa. Compared with the static test value (0.12 ml / h) at the same temperature and pressure, the leakage rate increased, indicating that the ice-breaking process may have caused microscopic effects or temporary disturbances to the sealing interface.

[0073] Step 4: Comprehensive data analysis and performance evaluation, such as... Figure 2 As shown at the end of the process, all test data has been integrated and processed. Specifically:

[0074] Data Association and Model Building: A three-dimensional response surface of "temperature-pressure-leakage rate" was plotted based on static test data. The image clearly shows that the critical degradation temperature range of the sealing performance is -35°C to -40°C. The dynamic leakage curve data was fitted to obtain a model for the leakage rate increasing with the number of cycles N: L(N) = 0.20 + 0.003 × N ml / h, with a goodness of fit R0. 2 The correlation coefficient was 0.96. Correlation analysis showed a strong correlation between severe leakage at -40 degrees Celsius and piston rod contraction exceeding 110 micrometers.

[0075] Failure Mechanism Diagnosis and Lifespan Prediction: Based on the above analysis, the valve component is diagnosed to fail at temperatures below -35 degrees Celsius due to the mismatch between the low-temperature hardening of the sealing material and the shrinkage of the metal valve body, leading to loss of the sealing gap and subsequent sealing failure. Using the obtained dynamic degradation model, the estimated cycle life of this valve component under constant temperature conditions of -30 degrees Celsius and subjected to sinusoidal pressure fluctuations of 3 to 9 MPa, with the leakage rate increasing to a threshold of 0.5 ml / hour, is approximately 100 cycles.

[0076] Generate evaluation report: The system automatically generates a comprehensive performance evaluation report that includes all test data, analysis charts, failure mechanism diagnosis, life prediction results, and improvement suggestions.

[0077] This invention patent constructs an internationally leading polar cryogenic valve sealing performance testing system. This method integrates a three-stage refrigeration system (liquid nitrogen precooling + compressor refrigeration + semiconductor temperature control) to achieve precise control over a wide temperature range from -70℃ to 0℃ (temperature uniformity ±0.3℃). It also innovatively introduces humidity control (5%~95% RH), wind speed regulation (0~10m / s), and ultraviolet radiation simulation (wavelength 280~400nm) to construct a polar climate model coupling all environmental factors. A micro-leakage detection scheme combining an infrared spectral absorption array sensor (detection limit 0.01mL / h) and laser-induced breakdown spectroscopy (LIBS) can identify nanoscale defects at the sealing interface.

[0078] The above embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A method for testing the sealing performance of cryogenic valve components based on multiphysics coupling, characterized in that, Includes the following steps: Step 1: System preparation and initial benchmark testing, establishing performance test benchmarks and confirming system status; specifically: Step 1.1: Install the valve to be tested onto the valve mounting and support assembly, and connect its drive line to the pipeline of the hydraulic servo loading unit; close the environmental simulation chamber door and perform a sealing check on the pipeline system at room temperature. Step 1.2: Start the hydraulic servo loading unit to apply the rated working pressure to the valve; control the valve to complete several opening-closing cycles, and at the same time use the micro-leakage detection unit to measure and record the reference leakage rate at room temperature and rated pressure, and use the deformation and temperature monitoring unit to record the initial size data of key parts to obtain the room temperature reference leakage rate and initial size. Step 2: Static low temperature sealing performance spectrum test, used to obtain the sealing performance matrix of valves under different steady-state low temperature and pressure combinations; Step 3: Dynamic environmental cycling and coupled stress testing, used to evaluate the cumulative and instantaneous effects of dynamic environmental stresses such as temperature cycling and icing on sealing performance; specifically: Step 3.1, Dynamic temperature-pressure cycle test; Select a critical low temperature point; At this temperature, control the hydraulic servo loading unit to make the system pressure fluctuate at a low frequency sinusoidal between the minimum and maximum allowable pressure, and continue to perform N cycles; During the entire cycle, use the micro-leakage detection unit to continuously monitor and record the transient change data of the leakage rate to obtain the dynamic leakage curve; Step 3.2, External spray icing test; stabilize the temperature of the main test chamber at another test point; start the spray icing device and periodically spray water on the outer surface of the valve until the ice layer thickness is ≥5mm; then, without using additional heating, break the ice and immediately operate the valve to complete the opening and closing action; record whether the valve operates normally after the ice breaking operation, and use the micro-leakage detection unit to measure the leakage rate after the icing-breaking process to obtain the functional status and leakage rate of the icing condition; Step 4: Data integration and performance evaluation. The baseline leakage rate obtained in Step 1, the static performance matrix obtained in Step 2, and the dynamic leakage curve and leakage rate after freezing obtained in Step 3 are input into the central control and data processing subsystem to perform integrated processing and decision-making on the test results.

2. The method for testing the sealing performance of polar cryogenic valves based on multiphysics coupling according to claim 1, characterized in that, Step 2 specifically includes: Step 2.1: Start the composite refrigeration unit to lower the temperature of the main test chamber to the first target low temperature point T1 at a certain rate and maintain it for at least 6 hours to make the valve temperature uniform and stable. Step 2.2: After the temperature T1 stabilizes, multiple static pressure points are applied to the valve in sequence through the hydraulic servo loading unit; for each pressure point, the valve is controlled to perform a switching action once and then closes to maintain pressure. After the pressure stabilizes, the steady-state leakage rate under this working condition is measured using the micro-leakage detection unit. Step 2.3: Repeat the above steps, and set the temperature of the main test chamber to other target low temperature points T2, T3...Tn in sequence, and complete the leakage rate test at all corresponding pressure points to obtain the static performance matrix.

3. The method for testing the sealing performance of polar cryogenic valves based on multi-physics coupling according to claim 2, characterized in that, In step 2.1, the temperature of the main test chamber is reduced to the first target low temperature point T1 at a rate not exceeding 10℃ / min.

4. The method for testing the sealing performance of polar cryogenic valves based on multi-physics coupling according to claim 1, characterized in that, Step 4 specifically includes: Step 4.1: First, analyze the static performance matrix, plot the three-dimensional response surface of leakage rate as a function of temperature and pressure, and identify the critical degradation temperature point of sealing performance. Step 4.2, next, analyze the dynamic leakage curve, extract the trend of leakage rate increasing with the number of cycles, fit the performance degradation curve, and quantify the fatigue effect; Step 4.3 Finally, combine all the data and conduct a comparative analysis; Calculate the growth rate of leakage rate at each low temperature point relative to the normal temperature baseline; analyze the correlation between excessive leakage rate at the critical temperature point and changes in material low-temperature hardness and sealing gap. Step 4.4, Failure Mechanism Diagnosis and Life Prediction: Based on the analysis results, diagnose the main modes of seal failure; using the performance degradation curve and combined with the accelerated life test model, predict the seal life of the valve under the target polar low temperature conditions. Step 4.5: Generate the evaluation report.

5. A polar cryogenic valve sealing performance testing system based on multiphysics coupling, characterized in that, The polar cryogenic valve sealing performance testing system described in any one of claims 1-4 implements the polar cryogenic valve sealing performance testing method. The polar cryogenic valve sealing performance testing system comprises an environmental simulation subsystem, a multi-axis loading and measurement subsystem, and a central control and data processing subsystem; specifically as follows: The environmental simulation subsystem is used to provide controllable low temperature and composite environments, including a low temperature environment simulation chamber, a composite refrigeration unit, and a spray icing device, with the low temperature environment simulation chamber being its core. The multi-axis loading and measurement subsystem is installed inside the main test chamber of the environmental simulation chamber and acts directly on the valve under test. It includes a valve mounting and support assembly, a hydraulic servo loading unit, and a multi-sensor fusion detection array composed of a micro-leakage detection unit, a deformation and temperature monitoring unit, and an electrical performance monitoring unit. Specifically: The central control and data processing subsystem is used to coordinate and control the entire testing process and process data.

6. The polar cryogenic valve sealing performance testing system based on multiphysics coupling according to claim 5, characterized in that, Specifically, the environmental simulation subsystem includes: Low-temperature environment simulation chamber: The interior of the chamber forms the main test chamber, which is used to accommodate the valve to be tested and some load measurement components; the chamber wall adopts a composite structure of polyurethane foam insulation layer and inner wall surface electric heating anti-condensation membrane, and the chamber door adopts double silicone rubber sealing strips. The combined refrigeration unit uses a combination of liquid nitrogen precooling circuit and cascade compressor refrigeration cycle, integrated into the environmental simulation chamber; Spray icing device: including array of spray nozzles, water supply pipelines and low temperature water circulation unit located in the cabin, used to simulate polar droplet freezing conditions.

7. The polar cryogenic valve sealing performance testing system based on multiphysics coupling according to claim 5, characterized in that, In the environmental simulation subsystem: the composite refrigeration unit can reduce the temperature of the main test chamber from room temperature to -70℃ at a rate of ≤10℃ / min, and stabilize it at any temperature point within the range of -70℃ to 0℃, with a temperature uniformity of ≤±2℃; the spray icing device can spray cold water at a temperature not higher than 2℃ onto the surface of the valve under test and designated locations.

8. The polar cryogenic valve sealing performance testing system based on multiphysics coupling according to claim 5, characterized in that, Specifically, the multi-axis loading and measurement subsystem includes: Valve mounting and support assembly: Constructed of an adjustable high-strength alloy steel bracket, used to fix the valve under test (such as an electro-hydraulic remote control valve assembly) and ensure its alignment with the test pipeline; Hydraulic servo loading unit: Composed of a high-pressure pump driven by a servo motor, an accumulator, a precision proportional pressure valve, and pipelines, connected to the inlet and outlet of the valve under test; Micro-leakage detection unit: Employs a high-precision mass flow meter, directly connected in series in the leak collection pipeline downstream of the valve, for quantitative measurement of the flow rate of the leaking medium; Deformation and temperature monitoring unit: includes multiple contact point thermometers (attached to key parts such as valve body and valve seat) and non-contact laser displacement sensor, used to monitor temperature distribution and mechanical deformation at low temperatures; Electrical performance monitoring unit: integrates an insulation resistance tester and a clamp meter to monitor the insulation resistance and operating current changes of the valve drive motor at low temperatures.

9. The polar cryogenic valve sealing performance testing system based on multiphysics coupling according to claim 8, characterized in that, In the multi-axis loading and measurement subsystem: the hydraulic servo loading unit can apply static pressure or dynamic alternating pressure from 0.1 MPa to 16 MPa; the detection limit of the micro-leakage detection unit can reach 0.1 mL / h.

10. The polar cryogenic valve sealing performance testing system based on multiphysics coupling according to claim 8, characterized in that, The contact thermometer is attached to the valve body, valve seat or other key parts, and the non-contact laser displacement sensor is aligned with the valve stem or actuator piston rod.

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