Large space air tightness detection system and method based on dynamic wind pressure

Abstract

This invention discloses a sealing performance testing system and method based on dynamic wind pressure, belonging to the field of sealing performance testing technology. The method constructs a controlled dynamic air pressure field within the volume to be tested using an adjustable dynamic air source, and utilizes a flow guiding structure and porous laminar flow elements for pressure stabilization and turbulence reduction. A distributed sensing array and dual sampling mode are used to synchronously collect effective pressure difference and environmental physical quantities in real time. Finally, based on fluid dynamics equations, combined with real-time density compensation and fluid viscosity property calibration, the equivalent leakage area is accurately calculated. The system also integrates a dynamic physical intervention and automatic scene parameter adaptation module. This invention effectively overcomes the impact of airflow turbulence and environmental temperature and humidity interference, significantly improves detection accuracy, and achieves high-efficiency, automated detection matching in multiple industrial scenarios.

Description

Technical Field

[0001] This invention relates to the field of sealing performance testing, and particularly to a large-space sealing performance testing system and method based on dynamic wind pressure. Background Technology

[0002] In industrial production, construction engineering, automotive manufacturing, and electronic equipment, the sealing performance of enclosed containers or spaces is a key indicator for evaluating their quality and safety. However, existing sealing testing methods and systems have several significant drawbacks: First, traditional methods such as the static pressure drop method typically require extremely long pressure stabilization and inflation times, resulting in extremely low testing efficiency when dealing with large-volume or complex-structured seals. Second, during dynamic inflation, existing equipment struggles to control airflow patterns, easily generating fluid turbulence and instantaneous airflow impacts, leading to drastic fluctuations in the pressure data collected by sensors and making it difficult to extract true pressure difference characteristics. Third, existing testing models often rely on idealized assumptions, severely neglecting the nonlinear effects of changes in ambient temperature gradients, background pressure fluctuations, and fluid kinematic viscosity with temperature during the testing process, resulting in significant systematic errors in the calculated leakage amount. Finally, current testing systems are mostly customized equipment for single, specific operating conditions, lacking the ability to adapt parameters to different industrial scenarios and various volume scales, exhibiting extremely poor versatility and failing to meet the flexible and intelligent production testing needs of modern industry. Summary of the Invention

[0003] To address the aforementioned problems in the existing technology, the present invention aims to provide a sealing performance testing method based on dynamic wind pressure, comprising the following steps: Step S1: Obtain the basic characteristic parameters of the sealed volume to be tested, establish fluid communication between the adjustable power air source unit and the interior of the sealed volume to be tested through the airtight connection component, and perform system initialization.

[0004] Step S2: Drive the adjustable power air source unit according to the preset power excitation control strategy to construct a dynamic air pressure field with a controlled pressure gradient or steady-state pressure distribution in the sealed volume to be tested.

[0005] Step S3: Real-time synchronous acquisition of pressure difference data, fluid state data, and environmental physical quantity compensation data inside and outside the sealed volume under test through a distributed sensing array.

[0006] Step S4: Based on the principle of fluid mass conservation and fluid dynamics equations, establish a mathematical model that reflects the mapping relationship between the pressure difference data and fluid flow characteristics, and modify the model by combining the environmental physical quantity compensation data, and calculate the equivalent leakage area of ​​the sealed volume to be measured.

[0007] Furthermore, in step S2, the adjustable power source unit is driven according to a preset power excitation control strategy, including any one or a combination of the following control methods: stepped pressurization control, which controls the power source unit to increase the output power step by step according to a preset power gradient, and maintains a preset stable duration at each power step to obtain multiple sets of pressure difference data under steady state; smooth start control: controlling the output rate of the power source unit according to a preset exponential rise curve to smooth out the instantaneous fluid impact on the small volume of the sealed volume to be tested.

[0008] Furthermore, the steps in step S3 for collecting and processing data include: A dual sampling mode is adopted: first, background environmental feature data is collected when the power air source unit is stationary, and then raw sensing data is collected when the power air source unit is running. The effective dynamic sensing data is extracted by subtracting the background environmental feature data from the raw sensing data, thereby eliminating the influence of environmental background noise on detection accuracy.

[0009] Furthermore, the environmental physical quantity compensation in step S3 includes temperature compensation and humidity correction, and its characteristic steps include: By utilizing temperature sensing units distributed within the sealed volume under test, and in conjunction with closed-loop control logic, the fluctuation range of the temperature gradient within the sealed volume under test is maintained below a preset threshold; a real-time fluid density compensation parameter is introduced during the environmental data acquisition process. The parameters The calculation satisfies the following formula: ,in, Standard atmospheric pressure For fluid molar mass, The gas constant is The initial ambient temperature, This represents the measured temperature increment.

[0010] Furthermore, the mathematical model described in step S4 calculates the equivalent leakage area of ​​the sealed volume to be tested based on the following formula. ,in, This refers to the real-time volumetric flow rate of the power air source unit. This refers to the effective dynamic pressure difference data inside and outside the sealed volume to be tested. The velocity coefficient is determined by the coupling of the geometry factor and the surface roughness factor. The real-time fluid density is the result of correction using the environmental physical quantity compensation data.

[0011] Furthermore, during the execution of step S4, the mathematical model is calibrated by physical property coupling using the fluid viscosity parameters acquired in real time: establishing a mapping relationship between fluid temperature and kinematic viscosity, and performing nonlinear compensation on the calculation results of the equivalent leakage area based on the mapping relationship.

[0012] Furthermore, in the process of constructing the dynamic pressure field in step S2, the flow field morphology is reshaped through fluid pressure stabilization and turbulence reduction. After the fluid is guided through a flow guide structure with a preset cross-sectional area change rate for initial pressure stabilization, the fluid in the sealed volume to be tested is smoothed using a porous laminar flow generating element.

[0013] A sealing performance testing system based on dynamic wind pressure includes a fluid pressure stabilization and diversion module and a dynamic physical intervention module. The fluid pressure stabilization and flow guiding module includes a flow guiding structure with a preset cross-sectional area change rate and a porous laminar flow generating element. It is configured to guide the fluid to flow through the flow guiding structure for initial pressure stabilization during the construction of a dynamic pressure field, and then use the porous laminar flow generating element to smooth the fluid in the sealed volume to be tested.

[0014] The dynamic physical intervention module is configured to use waveform driving technology and spiral physical gain structure to coordinately intervene in the operating state during the driving of the power air source unit, so as to suppress vibration noise during operation and to provide directional gain to the fluid flow velocity in the sealed volume to be tested.

[0015] Furthermore, it also includes a spatial perception and filtering module: The spatial sensing and filtering module includes a sensing array and a processing unit that is communicatively connected to the sensing array.

[0016] The sensing array includes multiple high-sensitivity differential pressure sensing units, which are arranged in a spatial array at preset symmetrical positions within the sealed volume to be measured; the processing unit is configured to perform spatial averaging on the data collected by the sensing array using a multi-point weighting algorithm.

[0017] Furthermore, it also includes a scene parameter automatic adaptation module: The automatic scene parameter adaptation module has a pre-built and stored feature database containing various industrial scenes and volume sizes within its storage unit.

[0018] The logic execution unit of the automatic scene parameter adaptation module is configured to automatically extract the power output range, stabilization time threshold, geometric shape factor and surface roughness factor corresponding to the scene from the feature database before the detection starts, based on the externally input scene command, and automatically load the corresponding detection protocol into the system.

[0019] Compared with existing technologies, the beneficial effects of this invention are as follows: By employing an adjustable power air source unit in conjunction with a stepped pressurization and smooth start-up control strategy, combined with a flow guide structure with a preset cross-sectional area change rate and a porous laminar flow generating element, this invention effectively suppresses the instantaneous impact of fluids and achieves the reshaping and turbulence reduction of the flow field morphology, providing an extremely stable dynamic air pressure field for high-precision detection; at the same time, it introduces a dual sampling mode to extract effective dynamic sensing data, and uses a distributed sensing array in conjunction with a multi-point weighted algorithm for spatial averaging, completely eliminating the interference of environmental background noise and local air pressure distortion on detection accuracy from both physical intervention and underlying algorithm dimensions.

[0020] This invention constructs an accurate calculation model for the equivalent leakage area based on the principle of fluid mass conservation. In the solution process, it innovatively introduces real-time fluid density compensation and nonlinear property coupling calibration based on the mapping relationship between fluid temperature and kinematic viscosity, fundamentally overcoming the calculation errors caused by temperature and humidity fluctuations in complex environments. In addition, the system's integrated scene parameter automatic adaptation module can automatically retrieve the corresponding power output range and detection protocol according to externally input scene commands, realizing fully automated and highly adaptive matching for sealing tests of cross-industry, multi-volume-scale equipment. Attached Figure Description

[0021] Figure 1 This is an exemplary flowchart of the detection method of the present invention.

[0022] Figure 2 This is a schematic diagram of the system module structure of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] like Figure 1 As shown, this embodiment provides a sealing performance testing method based on dynamic wind pressure, including the following steps: Step S1: Obtain the basic characteristic parameters of the sealed volume to be tested. Establish fluid communication between the adjustable power air source unit and the interior of the sealed volume to be tested through an airtight connection component, and perform system initialization. In one embodiment, the basic characteristic parameters of the sealed volume to be tested include its theoretical volume, theoretical surface area, and design pressure limit. The adjustable power air source unit uses a high-flow, low-pulsation vortex pump or a multi-stage centrifugal fan, and is equipped with a high-frequency proportional valve. The airtight connection component achieves rapid docking with the explosion-proof valve interface or reserved test hole of the battery pack shell through an automated cylinder-driven silicone sealing joint. System initialization includes performing zero-point calibration of the air circuit to ensure that the initial pressure state is consistent with the ambient atmospheric pressure.

[0025] Step S2: Drive the adjustable power air source unit according to the preset power excitation control strategy to construct a dynamic air pressure field with controlled pressure gradient or steady-state pressure distribution in the sealed volume to be tested.

[0026] In step S2, the adjustable power air source unit is driven according to a preset power excitation control strategy, including any one or a combination of the following control methods: stepped pressurization control, which controls the power air source unit to increase the output power step by step according to a preset power gradient, and maintains a preset stable duration at each power step to obtain multiple sets of steady-state pressure difference data; smooth start control: controlling the output rate of the power air source unit according to a preset exponential rise curve to smooth out the instantaneous fluid impact on the small volume of the sealed volume to be tested.

[0027] In the process of constructing a dynamic pressure field in step S2, the flow field morphology is reshaped through fluid pressure stabilization and turbulence reduction. After the fluid is guided through a flow guide structure with a preset cross-sectional area change rate for initial pressure stabilization, the fluid in the sealed volume to be tested is smoothed using a porous laminar flow generating element.

[0028] Step S3 involves real-time synchronous acquisition of pressure difference data, fluid state data, and environmental physical quantity compensation data inside and outside the sealed volume under test using a distributed sensing array. For example, the low-frequency infrasound generated by the operation of a large stamping machine in a factory can cause minute vibrations on the surface of the volume under test. These environmental vibrations are converted into pressure pulsations of the same frequency within the closed cavity. By subtracting the samples from the samples, this common-mode interference signal can be filtered out. Step S4: Based on the principle of fluid mass conservation and fluid dynamics equations, establish a mathematical model that reflects the mapping relationship between pressure difference data and fluid flow characteristics, and modify the model by combining environmental physical quantity compensation data to calculate the equivalent leakage area of ​​the sealed volume to be measured.

[0029] The steps in step S3 for collecting and processing data include: A dual sampling mode is adopted: first, background environmental feature data is collected when the power air source unit is stationary, and then raw sensing data is collected when the power air source unit is running. The effective dynamic sensing data is extracted by subtracting the background environmental feature data from the raw sensing data, thus eliminating the impact of environmental background noise on detection accuracy.

[0030] The environmental physical quantity compensation in step S3 includes temperature compensation and humidity correction, and its characteristic steps include: By utilizing temperature sensing units distributed within the sealed volume under test, and in conjunction with closed-loop control logic, the fluctuation range of the temperature gradient within the sealed volume under test is maintained below a preset threshold. In one embodiment, the closed-loop control logic controls the semiconductor cooling / heating element at the front end of the power air source to ensure that the temperature of the injected gas remains consistent with the temperature of the shell of the object under test, thereby suppressing the thermal expansion and contraction effect caused by Charles's Law from the source and introducing real-time fluid density compensation parameters during the environmental data acquisition process. ,parameter The calculation satisfies the following formula: ,in, Standard atmospheric pressure For fluid molar mass, The gas constant is The initial ambient temperature, This represents the measured temperature increase. Since the core of leakage assessment is mass flow rate rather than volumetric flow rate, and during pressurization, the gas undergoes compression, generating heat and causing a temperature increase. Temperature increase This will cause the gas to expand and its density to decrease. Reduce. Calculate dynamic density in real time. It can accurately convert the volumetric leakage rate into the mass leakage rate under standard conditions, eliminating the quantization error caused by temperature distortion.

[0031] In step S4, the mathematical model calculates the equivalent leakage area of ​​the sealed volume to be tested based on the following formula. ,in, This refers to the real-time volumetric flow rate of the power air source unit. This refers to the effective dynamic pressure difference data inside and outside the sealed volume to be tested. The velocity coefficient is determined by the coupling of the geometry factor and the surface roughness factor. This is the real-time fluid density after correction using environmental physical quantity compensation data.

[0032] Assuming the leak hole is a tiny nozzle, when the sealed volume reaches a steady-state pressure, the flow rate continuously supplied by the air source... This is exactly equal to the flow rate escaping from the leak. According to the law of conservation of energy, the pressure difference potential energy is converted into kinetic energy, and the theoretical flow velocity... The actual leakage orifice is not an ideal streamlined nozzle; its geometry (such as crack aspect ratio) and orifice wall roughness will cause local head loss. Therefore, a comprehensive velocity coefficient k is introduced for correction. Finally, through actual measurement... and The equivalent area characterizing the severity of the leak is obtained by inverse solving. Compared to traditional leak rate units, equivalent leak area... It does not change with the test pressure, making it a more accurate and absolute indicator of the inherent physical defects of a product.

[0033] During step S4, the mathematical model is calibrated by physical property coupling using the fluid viscosity parameters acquired in real time. This involves establishing a mapping relationship between fluid temperature and kinematic viscosity, and performing nonlinear compensation on the calculation results of the equivalent leakage area based on the mapping relationship.

[0034] like Figure 2 As shown, this embodiment also provides a sealing performance testing system based on dynamic wind pressure, including a fluid pressure stabilization and diversion module and a dynamic physical intervention module: The fluid pressure stabilization and flow guiding module includes a flow guiding structure with a preset cross-sectional area change rate and a porous laminar flow generating element. It is configured to guide the fluid to flow through the flow guiding structure for initial pressure stabilization during the construction of a dynamic air pressure field, and then use the porous laminar flow generating element to smooth the fluid in the sealed volume to be tested.

[0035] The dynamic physics intervention module is configured to collaboratively intervene in the operating state of the driving power air source unit using waveform driving technology and a spiral physical gain structure to suppress vibration noise during operation and to provide directional gain to the fluid flow velocity within the sealed volume under test. In one embodiment, waveform driving technology refers to the motor driver outputting a PWM chopping signal of a specific frequency to avoid the mechanical resonance point of the fan; the spiral physical gain structure is similar to the stator guide vanes of an aircraft engine, converting rotating vortices into axial straight airflow and improving wind pressure conversion efficiency.

[0036] This embodiment also includes a spatial perception and filtering module: The spatial sensing and filtering module includes a sensing array and a processing unit that is communicatively connected to the sensing array.

[0037] The sensing array comprises multiple high-sensitivity differential pressure sensing units, which are spatially arrayed at predetermined symmetrical positions within the sealed volume to be tested. The processing unit is configured to perform spatial averaging on the data collected by the sensing array using a multi-point weighted algorithm. Because the pressure gradient distribution inside the large-volume cavity is uneven during dynamic inflation, a sensor at a single location cannot represent the overall pressure. The multi-point weighted averaging algorithm assigns lower weights to probes closer to the air inlet and higher weights to probes in distant dead zones, thereby quickly fitting the global average static pressure value of the cavity.

[0038] This embodiment also includes a scene parameter automatic adaptation module: The scene parameter automatic adaptation module has a feature database pre-built and stored in its storage unit, which includes various industrial scenes and volume sizes.

[0039] The logic execution unit of the scene parameter automatic adaptation module is configured to automatically extract the power output range, stabilization time threshold, geometric shape factor and surface roughness factor corresponding to the scene from the feature database before the detection starts, based on the externally input scene command, and automatically load the corresponding detection protocol into the system.

Claims

1. A method for detecting tightness based on dynamic wind pressure, characterized in that, Includes the following steps: Step S1: Obtain the basic characteristic parameters of the sealed volume to be tested, establish fluid communication between the adjustable power air source unit and the interior of the sealed volume to be tested through the airtight connection component, and perform system initialization; Step S2: Drive the adjustable power air source unit according to the preset power excitation control strategy to construct a dynamic air pressure field with a controlled pressure gradient or steady-state pressure distribution in the sealed volume to be tested. Step S3: Real-time synchronous acquisition of pressure difference data, fluid state data, and environmental physical quantity compensation data inside and outside the sealed volume under test through a distributed sensing array; Step S4: Based on the principle of fluid mass conservation and fluid dynamics equations, establish a mathematical model that reflects the mapping relationship between the pressure difference data and fluid flow characteristics, and modify the model by combining the environmental physical quantity compensation data, and calculate the equivalent leakage area of ​​the sealed volume to be measured.

2. The dynamic wind pressure based leak detection method of claim 1, wherein: In step S2, the adjustable power air source unit is driven according to a preset power excitation control strategy, including any one or a combination of the following control methods: stepped pressurization control, which controls the power air source unit to increase the output power step by step according to a preset power gradient, and maintains a preset stable duration at each power step to obtain multiple sets of steady-state pressure difference data; smooth start control: controlling the output rate of the power air source unit according to a preset exponential rise curve to smooth out the instantaneous fluid impact on the small volume of the sealed volume to be tested.

3. The dynamic wind pressure based leak detection method of claim 1, wherein: The steps in step S3 for collecting and processing data include: A dual sampling mode is adopted: first, background environmental feature data is collected when the power air source unit is stationary, and then raw sensing data is collected when the power air source unit is running. The effective dynamic sensing data is extracted by subtracting the background environmental feature data from the raw sensing data, thereby eliminating the influence of environmental background noise on detection accuracy.

4. The sealing performance testing method based on dynamic wind pressure according to claim 1, characterized in that: The environmental physical quantity compensation in step S3 includes temperature compensation and humidity correction, and its characteristic steps include: By utilizing temperature sensing units distributed within the sealed volume under test, and in conjunction with closed-loop control logic, the fluctuation range of the temperature gradient within the sealed volume under test is maintained below a preset threshold; a real-time fluid density compensation parameter is introduced during the environmental data acquisition process. The parameters The calculation satisfies the following formula: ,in, Standard atmospheric pressure For fluid molar mass, The gas constant is... The initial ambient temperature, This represents the measured temperature increment.

5. The sealing performance testing method based on dynamic wind pressure according to claim 1, characterized in that: The mathematical model described in step S4 calculates the equivalent leakage area of ​​the sealed volume to be tested based on the following formula. ,in, This refers to the real-time volumetric flow rate of the power air source unit. This refers to the effective dynamic pressure difference data inside and outside the sealed volume to be tested. The velocity coefficient is determined by the coupling of the geometry factor and the surface roughness factor. The real-time fluid density is the result of correction using the environmental physical quantity compensation data.

6. The sealing performance testing method based on dynamic wind pressure according to claim 1, characterized in that: During step S4, the mathematical model is calibrated by physical property coupling using the fluid viscosity parameters acquired in real time. This involves establishing a mapping relationship between fluid temperature and kinematic viscosity, and performing nonlinear compensation on the calculation results of the equivalent leakage area based on the mapping relationship.

7. The sealing performance testing method based on dynamic wind pressure according to claim 1, characterized in that: In the process of constructing a dynamic pressure field in step S2, the flow field morphology is reshaped through fluid pressure stabilization and turbulence reduction. After the fluid is guided through a flow guide structure with a preset cross-sectional area change rate for initial pressure stabilization, the fluid in the sealed volume to be tested is smoothed using a porous laminar flow generating element.

8. A sealing performance testing system based on dynamic wind pressure, characterized in that, Includes a fluid pressure stabilization and flow guiding module and a dynamic physical intervention module: The fluid pressure stabilization and flow guiding module includes a flow guiding structure with a preset cross-sectional area change rate and a porous laminar flow generating element. It is configured to guide the fluid to flow through the flow guiding structure for initial pressure stabilization during the construction of a dynamic pressure field, and then use the porous laminar flow generating element to smooth the fluid in the sealed volume to be tested. The dynamic physical intervention module is configured to use waveform driving technology and spiral physical gain structure to coordinately intervene in the operating state during the driving of the power air source unit, so as to suppress vibration noise during operation and to provide directional gain to the fluid flow velocity in the sealed volume to be tested.

9. A sealing performance testing system based on dynamic wind pressure according to claim 7, characterized in that, It also includes a spatial perception and filtering module: The spatial sensing and filtering module includes a sensing array and a processing unit that is communicatively connected to the sensing array. The sensing array includes multiple high-sensitivity differential pressure sensing units, which are arranged in a spatial array at preset symmetrical positions within the sealed volume to be measured; the processing unit is configured to perform spatial averaging on the data collected by the sensing array using a multi-point weighting algorithm.

10. A sealing performance testing system based on dynamic wind pressure according to claim 7, characterized in that, It also includes a scene parameter automatic adaptation module: The scene parameter automatic adaptation module has a feature database pre-built and stored in its storage unit, which includes various industrial scenes and volume sizes. The logic execution unit of the automatic scene parameter adaptation module is configured to automatically extract the power output range, stabilization time threshold, geometric shape factor and surface roughness factor corresponding to the scene from the feature database before the detection starts, based on the externally input scene command, and automatically load the corresponding detection protocol into the system.

Images