Device and method for testing heat and mass coupling transportation characteristics of porous plate

Abstract

The invention provides a device and a method for testing heat and mass coupling transportation characteristics of a porous plate. The device comprises a profile frame, a laser generator, a laser head, a variable layout fixing frame, a precision balance, a laser power meter, a sample clamping platform, a liquid level keeping device, a thermal infrared imager, a computer, a power supply and a water cooling module. The method is implemented on the basis of the device, temperature distribution data and mass change data of a porous plate to-be-tested piece are collected, and heat and mass transport characteristic parameters of the to-be-tested piece are calculated on the basis of a preset thermodynamics and mass transfer theory theoretical model. According to the device and the method, synchronous in-situ measurement of the thermal mass flow multi-physical field of the porous plate can be realized, the test precision and the data repeatability are guaranteed, the adaptability to the size of a to-be-tested piece of the porous plate is high, and the operation automation degree is high. The device and the method provided by the invention are mainly applied to thermal control design of spacecrafts, and adapt to related fields of porous material thermal mass coupling transport characteristic testing.

Description

Technical Field

[0001] This invention relates to the field of spacecraft thermal control design technology, and more specifically, to a device and method for testing the thermal-mass coupling transport characteristics of porous plates. Background Technology

[0002] Porous materials play a crucial role in spacecraft thermal control systems due to their excellent heat and mass transfer properties and adaptability to extreme environments. They are often used in core components such as loop heat pipe flat plate evaporators, achieving efficient thermal management through the wetting, phase change, and evaporation processes of liquid working fluids, directly affecting the stability and reliability of spacecraft in orbit.

[0003] Current testing techniques for the heat and mass transport properties of porous plates mainly include harmonic methods and steady-state methods, with heating methods primarily employing quartz lamp radiation heating or electromagnetic induction heating. These existing technologies generally have significant limitations: First, current measurement modes mostly involve decoupled testing of heat and mass transfer processes, failing to simultaneously capture the interaction between heat transfer, working fluid flow, and phase change evaporation, leading to significant deviations between test data and actual operating conditions. Second, existing heating methods cannot accurately simulate the thermal load requirements of spacecraft under different operating conditions. Third, the sample clamping structures of existing experimental devices have low adaptability, failing to flexibly meet the testing needs of porous plates of different sizes, and lack precise control of the liquid working fluid level, making it difficult to maintain a stable phase change wetting interface. Furthermore, existing devices have limited control accuracy, lack an effective power closed-loop calibration mechanism, and have inadequate safety protection designs and low automation levels, affecting the repeatability of test data and operational safety.

[0004] Therefore, there is an urgent need for a test device and method for the thermal-mass coupling transport characteristics of porous plates that can achieve synchronous in-situ measurement of the thermal-mass coupling process, uniform heating with adjustable power, strong sample adaptability, precise control, and safety and reliability. This would solve the problems of data distortion in decoupling measurement, insufficient heating and control accuracy, narrow sample adaptability range, and lack of safety protection in the existing technology, and provide reliable data support for the optimized design of spacecraft thermal control systems. Summary of the Invention

[0005] Based on existing technologies, the objective of this invention is to provide a device and method for testing the thermo-mass coupling transport characteristics of porous plates. This device and method can solve problems such as data distortion in decoupled measurement of porous plates, insufficient heating and control precision, narrow sample compatibility range, and lack of safety protection in existing technologies. It enables synchronous, in-situ, and coupled measurement of multiple physical fields of heat, mass, and flow inside porous plates, thereby providing direct experimental evidence for revealing their true synergistic transport mechanism and establishing a high-precision prediction model.

[0006] According to the present invention, the above-mentioned task is solved by a device and method for testing the thermal-mass coupling transport characteristics of porous plates.

[0007] In a first aspect, the present invention provides a testing device for the thermal-mass coupling transport characteristics of porous plates, the device comprising: Profile frame; A laser head, which is movably arranged on the profile frame and configured to emit a laser to irradiate a test piece, wherein the test piece is a porous plate. A laser power meter, which is movably arranged on a profile frame and configured to measure the power of the laser emitted by the laser head; A precision balance configured to detect changes in the mass of the test piece; A sample clamping platform is arranged on the precision balance and configured to hold the sample to be tested. A liquid level maintaining device is disposed on one side of the sample clamping platform, connected to the sample clamping platform, and configured to adjust or maintain the liquid level of the liquid working fluid; and An infrared thermal imager is configured to visualize the temperature field distribution on the surface of the test piece.

[0008] Furthermore, the device also includes: A laser generator is arranged on the profile frame and coupled to the laser head via an optical fiber. The laser generator is configured to generate continuous or pulsed laser light. A variable-layout mounting bracket is arranged on the profile frame and configured to support the laser head, laser power meter, and precision balance. The computer is electrically connected to the laser generator, laser power meter, precision balance and infrared thermal imager respectively; The power supply is arranged on the profile frame and is electrically connected to the laser generator, laser power meter, precision balance, infrared thermal imager and computer; A programmable interface, configured to connect to a host computer for programmed workflow arrangement and / or remote control; and A local operation panel is configured to perform manual parameter settings and / or operations on the device.

[0009] Furthermore, the variable layout mounting bracket includes: The precision balance, sample clamping platform, and liquid level maintaining device are all arranged on the support platform. A column, fixedly connected to the supporting platform and perpendicular to the surface of the supporting platform; and The bracket is movably connected to the column by locking bolts. The bracket can move along the length of the column to adjust its height, and the bracket can rotate around the column to adjust its orientation. The bracket includes a first bracket and a second bracket. The laser power meter is arranged on the first bracket, and the laser head and the infrared thermal imager are arranged on the second bracket.

[0010] Furthermore, the laser head includes a homogenization component and a lens module, wherein: The homogenization component and lens module integrate the processing of the laser generated by the laser generator and output a square flat-top light spot. The size of the light spot can be adjusted by replacing the lens module.

[0011] Furthermore, the sample clamping platform is equipped with multiple sets of limiters of different sizes, wherein: Each set of limiters includes four clamping columns arranged symmetrically about the center of the sample clamping platform. Each clamping column is provided with a groove, and the test piece is fixedly clamped in the grooves of the four clamping columns.

[0012] Furthermore, the liquid level maintaining device includes: A liquid storage container is constructed as a closed container to store liquid working fluid; The liquid level control area is connected to the sample clamping platform, forming a communicating vessel; A miniature peristaltic pump, connected in series between the liquid storage container and the liquid level control zone, is configured to transport the liquid working fluid from the liquid storage container to the liquid level control zone; and A baffle is arranged on one side of the liquid level control area, the height of the baffle is adjustable, and it is configured to control the liquid level height of the liquid level control area.

[0013] Furthermore, the device also includes a water-cooling module electrically connected to the computer and the power supply, wherein the water-cooling module comprises: The water chiller and water cooling pipes are configured to form a complete closed-loop cooling path, through which the coolant circulates to provide heat dissipation for the laser generator and the laser head. A heat exchanger configured to connect to an external cold source and to achieve heat exchange with the coolant; and A thermostat is configured to monitor the flow rate and temperature parameters of the coolant in real time and limit coolant temperature fluctuations within a preset range through closed-loop control.

[0014] Furthermore, the profile frame is an aluminum alloy profile frame, and its bottom is equipped with casters with locking mechanisms, wherein: The profile frame has a double-layer structure, with the power supply and the water chiller arranged at the bottom layer of the profile frame, and the remaining components of the device arranged at the top layer of the profile frame.

[0015] A second aspect of the present invention provides a method for testing the thermal-mass coupling transport characteristics of porous plates, characterized in that it utilizes the apparatus proposed in the first aspect of the present invention, and the method includes: Place the device stably and lock it using the casters, then turn on the power supply, water chiller, computer, laser generator, infrared thermal imager, and precision balance in sequence to complete the power-on initialization. The laser output power is calibrated using the laser power meter to establish thermal boundary conditions; The porous plate test specimen is fixed to the center of the sample clamping platform by a limiter. The liquid level maintaining device is used to inject liquid working medium into the sample clamping platform and the liquid level height is adjusted by adjusting the baffle of the liquid level maintaining device so that the bottom of the test specimen is just immersed in the liquid working medium. The laser generator is activated, outputting a laser beam that irradiates the surface of the test piece to apply a thermal load. Simultaneously, the surface temperature distribution of the test piece is recorded using an infrared thermal imager, and the mass change of the test piece is recorded using a precision balance. Based on the collected temperature distribution data and mass change data, the thermal and mass transport characteristics parameters of the test piece are calculated.

[0016] Furthermore, the heat and mass transport characteristic parameters include the equivalent thermal conductivity and / or the phase change heat transfer coefficient.

[0017] Furthermore, the calculation of the equivalent thermal conductivity and phase change heat transfer coefficient includes: The radiant energy from the surface of the test piece acquired by the infrared thermal imager is converted into a surface temperature field. ; A three-dimensional heat conduction model is provided, including the laser heat source and phase change heat dissipation, with the governing equations as follows: in, Indicates the equivalent density of the test specimen; This indicates the specific heat capacity of the test specimen; This represents the equivalent thermal conductivity of the test piece; This represents the heat source term per unit volume corresponding to laser loading; The boundary conditions for the evaporation surface of the test piece are provided, and its energy balance equation is as follows: in, This represents the laser input heat flux density; This indicates convective heat transfer loss; Indicates heat radiation loss; This indicates that the evaporation phase change consumes heat; The heat consumption of the evaporation phase change is expressed as: in, Indicates the phase change heat transfer coefficient; Indicates the surface temperature of the test piece; Indicates the saturation temperature under the current pressure; and According to the heat conduction model, the equivalent thermal conductivity and / or phase change heat transfer coefficient are obtained by parameter inversion calculation from the surface temperature field.

[0018] Furthermore, the parameter inversion calculation includes: The predicted values ​​of the equivalent thermal conductivity and / or phase change heat transfer coefficient are provided and substituted into the heat conduction model to calculate the numerical simulation temperature. Based on the measured temperature of the temperature field, the objective function is defined as follows: in, Indicates the measured temperature; This represents the temperature in the numerical simulation. M Indicates the total number of nodes in the space; N Indicates the total number of time collection points; Provide sensitivity coefficient ,in These are heat and mass transport characteristic parameters; the degree of responsiveness of these parameters to changes in temperature is determined; and The predicted values ​​are adjusted using an iterative optimization method, and the priority and / or step size of the iterative adjustment of parameters are determined by combining the sensitivity coefficient, until the objective function is achieved. If the value is less than the preset threshold or the parameter change meets the convergence requirements, the final equivalent thermal conductivity and / or phase change heat transfer coefficient will be output.

[0019] The present invention provides a device and method for testing the thermo-mass coupling transport characteristics of porous plates, which has at least the following beneficial effects: (1) The testing device of the present invention uses a high-purity laser heat source with continuously adjustable energy density, which can achieve rapid, uniform, precise and controllable energy loading on the surface of the specimen. At the same time, the device integrates a non-contact full-field temperature measurement and real-time weighing system, realizing for the first time in the experimental stage the synchronous in-situ measurement of the multi-physics field of thermal mass flow of porous plates, effectively overcoming the inherent limitations of traditional decoupled research methods. With the addition of closed-loop calibration and stable power supply modules, the high precision of boundary conditions and the high repeatability of experimental data are further guaranteed, and finally the high-precision characterization of the basic thermal mass transport characteristics of porous plates is achieved, laying a reliable experimental foundation for subsequent research.

[0020] (2) The test method of the present invention achieves dynamic capture of complex coupled processes by programmatically controlling the application of heat load and synchronously collecting temperature field evolution and evaporation mass loss data. Then, by establishing a three-dimensional heat conduction model including laser heat source and phase change heat dissipation, the surface temperature field obtained by measurement is inverted and iteratively optimized to obtain the equivalent thermal conductivity, phase change heat transfer coefficient and other heat and mass transport characteristic parameters of porous plate. A standardized and traceable test process is formed, which provides a reliable basis for quantitative evaluation and comparison of the comprehensive transport performance of different materials and solves the problems of inconsistent process and inaccurate parameter acquisition in traditional test methods.

[0021] (3) The testing device and testing method of the present invention embody a high degree of system integration and automation. Key processes such as laser power control, data synchronous acquisition, safety interlock and result processing are all centrally managed. The operation is simple and the repeatability is excellent. It can accurately obtain the thermal-mass coupling characteristics of porous plates under simulated real working conditions, effectively make up for the shortcomings of existing technologies in the lack of test data and poor adaptability under complex working conditions, and provide solid theoretical data support and indispensable experimental means for the research and development and engineering application of related materials.

[0022] In summary, the testing device and method of this invention solve the problems of data distortion in decoupled measurement of porous plates, insufficient heating and control accuracy, narrow sample compatibility range, and lack of safety protection in the prior art. It is mainly applied in the field of spacecraft thermal control design, providing key experimental support for the core material screening, performance prediction, and optimization design of loop heat pipe flat plate evaporators. At the same time, it can be widely adapted to related fields such as new energy, energy storage, heat dissipation of electronic equipment, and building energy conservation, which involve the testing of thermal and mass coupling transport characteristics of porous materials, and meet the high-precision requirements for material performance evaluation in different scenarios. Attached Figure Description

[0023] To further illustrate the advantages and other features of the various embodiments of the present invention, a more specific description of the embodiments of the present invention will be presented with reference to the accompanying drawings. It is understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by the same or similar reference numerals for clarity.

[0024] Figure 1 The structure of the thermal-mass coupling transport characteristics testing device for porous plates proposed in this invention is shown.

[0025] Figure 2 The structure of the variable layout fixture is shown.

[0026] Figure 3 The structure of the liquid level maintaining device is shown.

[0027] Figure 4 The structure of the sample clamping platform and limiter is shown.

[0028] Figure 5 The flowchart of the test method for the thermal-mass coupling transport characteristics of porous plates proposed in this invention is shown.

[0029] Figure 6 The calculation process for equivalent thermal conductivity and phase change heat transfer coefficient in one embodiment of the present invention is shown.

[0030] List of reference numerals 1. Universal wheel 2. Profile Frame 3. Water chiller 4. Variable layout mounting bracket 4-1 Supporting Platform 4-2 Columns 4-3 First support 4-4 Second support 5. Precision Balance 6. Laser Power Meter 7 Laser Heads 8. Infrared thermal imager 9 Sample clamping platform 10 Liquid level maintaining device 10-1 Liquid storage container 10-2 Miniature Peristaltic Pump 10-3 Liquid Level Control Area 10-4 baffle 11 Computer 12 Laser Generator 13 Power Supply 14 Fixing bolt holes 15 Limiters Detailed Implementation It should be noted that the components in the various figures may be shown exaggeratedly for illustrative purposes and are not necessarily to scale. In each figure, the same reference numerals are used for components that are identical or have the same function.

[0031] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0032] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.

[0033] It should also be noted that, in the embodiments of the present invention, only a portion of the components or parts may be shown for clarity and simplicity. However, those skilled in the art will understand that, under the teachings of the present invention, necessary components or parts can be added as needed for specific scenarios. Furthermore, unless otherwise stated, features in different embodiments of the present invention can be combined with each other. For example, a feature in the second embodiment can replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment will also fall within the scope of disclosure or description of this application.

[0034] It should also be noted that within the scope of this invention, the terms "same", "equal", and "equal to" do not mean that the two values ​​are absolutely equal, but allow for a certain reasonable error. In other words, the terms also cover "substantially the same", "substantially equal", and "substantially equal to".

[0035] Furthermore, the steps of the methods of the present invention are not limited in terms of the execution order of the method steps. Unless otherwise specified, the method steps may be executed in different orders.

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] Figure 1 The structure of the thermal-mass coupling transport characteristics testing device for porous plates proposed in this invention is shown.

[0038] like Figure 1 As shown, in one embodiment of the present invention, the testing device 100 for the thermal-mass coupling transport characteristics of a porous sheet material test piece includes a caster wheel 1, a profile frame 2, a water chiller 3, a variable layout fixing frame 4, a precision balance 5, a laser power meter 6, a laser head 7, an infrared thermal imager 8, a sample clamping platform 9, a liquid level maintaining device 10, a computer 11, a laser generator 12, a power supply 13, fixing bolt holes 14, and a limiter 15. The structure, function, and connection relationship of each component are further described below with reference to specific embodiments of the present invention.

[0039] In one embodiment of the present invention, the testing device 100 adopts a profile frame 2 as a supporting structure, which is configured to provide an installation base for all components of the testing device. The components are arranged on the frame according to functional zones. The rigid structure of the frame ensures the stability of the relative positions between the components, thus ensuring the reliability of the optical path, circuit, and mechanical connections. Preferably, the profile frame 2 is a high-strength aluminum alloy profile frame.

[0040] In one embodiment of the present invention, the profile frame 2 is configured as a double-layer structure, wherein the large components of the testing device 100 are fixed in the lower layer of the profile frame 2, and the small components are fixed in the upper layer of the profile frame 2. In a specific embodiment of the present invention, the water chiller 3 and the power supply 13 are arranged in the lower layer of the profile frame 2, and the variable layout fixing frame 4, the precision balance 5, the laser power meter 6, the laser head 7, the infrared thermal imager 8, the sample clamping platform 9, the liquid level maintaining device 10, the computer 11, and the laser generator 12 are arranged in the upper layer of the profile frame 2.

[0041] In one embodiment of the present invention, a caster wheel 1 with a locking mechanism is installed at the bottom of the profile frame 2. It is configured to take into account both the ease of movement and the stability of operation of the entire testing device 100. When the testing device 100 needs to be placed in a designated testing position, the caster wheel 1 is fixed by the locking mechanism to prevent the testing device 100 from shifting during the testing process.

[0042] In one embodiment of the present invention, the laser generator 12 is securely mounted on the profile frame 2 by a bracket. The power to the laser generator 12 is supplied by a power supply 13 and cooled by a water chiller 3. The laser generator 12 is preferably a modular, water-cooled single-wavelength direct semiconductor laser capable of generating continuous or pulsed laser light, and outputting it through a 600μm fiber. Its main technical parameters are as follows: Output power 200-2000W (its output power is continuously adjustable, with an adjustment range of 10%-100%). Center wavelength 920nm (wavelength range 910-930nm); and Laser efficiency > 45%.

[0043] Figure 2 The structure of the variable layout fixture is shown.

[0044] In one embodiment of the present invention, the variable layout mounting bracket 4 is configured as an adjustable rigid fixing structure, fixedly installed above the profile frame 2, for mounting components that require flexible position adjustment. The distance and relative position between the components mounted thereon and the test area can be precisely adjusted according to testing requirements, adapting to the testing requirements of samples of different specifications. Specifically, the variable layout mounting bracket 4 includes: The load-bearing platform 4-1 is preferably a rigid material platform; Column 4-2 is fixed to the bearing platform and is perpendicular to the plane of the bearing platform; The bracket is fixedly connected to the column by bolts. The bracket can move along the length of the column to adjust its height, and the bracket can rotate around the column to adjust its orientation. The bracket includes a first bracket 4-3 and a second bracket 4-4.

[0045] In embodiments of the present invention, the variable layout mounting bracket 4 may include one or more supports to achieve fixing and positional adjustment of different components.

[0046] In one embodiment of the present invention, the laser head 7 is mounted on the second bracket 4-4 of the variable layout mounting bracket 4, and the distance between the laser outlet of the laser head 7 and the heating plane can be changed by adjusting the second bracket 4-4. The laser head 7 is connected to the laser generator 12 via optical fiber. During operation, the laser generated by the laser generator 12 is transmitted to the laser head 7 via optical fiber, and after optical processing by the laser head 7, it is output as a high-quality, highly uniform square flat-top light spot.

[0047] In one embodiment of the present invention, the laser head 7 includes a homogenization component and a lens module. The homogenization component and the lens module integrate the processing of the laser generated by the laser generator 12 and output a square flat-top light spot. The uniformity of the square flat-top light spot is better than 95%, the standard spot size is 50mm × 50mm, and the spot size can be adjusted to other sizes, such as 100mm × 100mm or 20mm × 20mm, by replacing the lens module to meet the radiation heating requirements of different test areas.

[0048] In one embodiment of the present invention, the sample clamping platform 9, the liquid level holding device 10, and the precision balance 5 together constitute a sample clamping module, which is stably mounted on a variable layout mounting frame 4. The sample clamping platform 9 is a rigid platform configured to support the porous plate specimen to be tested, achieving precise positioning and fixation of the specimen, ensuring that the surface of the specimen is within the precise irradiation area of ​​the laser spot, and providing support for the formation of a wetting interface between the specimen and the liquid working medium. The liquid level holding device 10 is installed on one side of the sample clamping platform 9 and is configured to precisely control the liquid level of the liquid working medium, ensuring that the bottom of the specimen can continuously and fully contact the liquid working medium, forming a stable phase change wetting interface and compensating for the liquid level loss caused by the evaporation of the liquid working medium. The precision balance 5 is installed at the bottom of the sample clamping platform 9, and its function is to continuously monitor the overall mass change of the sample clamping platform 9, the liquid level holding device 10, the specimen to be tested, and the liquid working medium in real time. Through the mass change data, the cumulative evaporation of the liquid working medium in the specimen during the heating process can be indirectly obtained. During operation, the sample clamping module ensures that the laser spot can accurately irradiate the surface of the sample to be tested, and simultaneously collects evaporation quality data.

[0049] Figure 3 The structure of the liquid level maintaining device is shown.

[0050] In one embodiment of the present invention, the liquid level maintaining device 10 includes: The liquid storage container 10-1 is constructed as a sealed cavity structure for storing liquid working fluid; A miniature peristaltic pump 10-2 is connected in series between the liquid storage container 10-1 and the liquid level control zone 10-3, and is configured to slowly replenish the liquid working fluid from the liquid storage container 10-1 to the liquid level control zone 10-3; The liquid level control area 10-3 is connected to the sample clamping platform 9, thus forming a communicating vessel; and Baffle 10-4 is set on one side of liquid level control area 10-3. The height of baffle 10-4 is adjustable and is used to control the maximum liquid level height of liquid level control area 10-3.

[0051] In one embodiment of the present invention, when the testing device 100 is working, due to the principle of communicating vessels, after the liquid working medium is injected into the sample clamping platform 9 by the liquid level holding device 10, the liquid level height in the liquid level control area 10-3 can be changed by operating the baffle 10-4, so as to control the liquid level height in the sample clamping platform 9 so that it just submerges the bottom of the test piece and forms a stable phase change wetting interface.

[0052] Figure 4 The structure of the sample clamping platform and limiter is shown.

[0053] In one embodiment of the present invention, the sample clamping platform 9 is generally square, with fixing bolt holes 14 at its four corners for fixing the sample clamping platform 9 to the variable layout fixing frame 4. The variable layout fixing frame 4 is provided with coaxial mounting holes corresponding to the fixing bolt holes 14, and the profile frame 2 is also provided with corresponding coaxial mounting holes, so as to realize the bolt fixing between the sample clamping platform 9, the variable layout fixing frame 4 and the profile frame 2.

[0054] In one embodiment of the present invention, the sample clamping platform 9 is provided with multiple sets of limiters 15. The limiters 15 are generally frame-like structures adapted to the square test piece, including four clamping columns arranged symmetrically to the center of the sample clamping platform 9. Each clamping column has a groove that opens toward the center of the sample clamping platform 9. The groove has three mutually perpendicular planes, and its outline is adapted to the four corners of the test piece for clamping and precisely controlling the position of the test piece.

[0055] In one embodiment of the present invention, the spacing between the multiple sets of limiters 15 clamping the columns is adjusted according to the size of the adapted test piece. Simultaneously, the greater the spacing between the clamping columns, the higher their height, ensuring that the limiters 15 clamping small-sized test pieces do not interfere with the clamping of large-sized test pieces.

[0056] In one embodiment of the present invention, the testing device 100 is equipped with a local operation panel and a computer 11. Users can quickly set parameters and perform manual operations through the local operation panel, and can also use the computer 11 to perform complex data acquisition, programmed process arrangement and remote control.

[0057] In one embodiment of the present invention, the infrared thermal imager 8 is arranged on the second bracket 4-4 of the variable layout fixture 4 and is configured to realize real-time monitoring and recording of the surface temperature field of the test piece. In a specific embodiment of the present invention, the infrared thermal imager 8 is preferably a FLIR A70 infrared thermal imager, which has a temperature measurement range of -20 to 175°C, an infrared resolution of 640×480, and a field of view of 29°, which can meet the requirements of accurate acquisition of spatial temperature distribution for testing the thermal-mass coupling transport characteristics of porous plates.

[0058] In one embodiment of the present invention, the laser power meter 6 is arranged on the first bracket 4-3 of the variable layout fixture 4 and integrated into the optical path of the test device 100. Its test surface size is configured to fully cover the light spot output by the laser generator 12 and integrated by the laser head 7. The output power is sampled and measured periodically or in real-time, and the measurement data is fed back to the computer 11. In a specific embodiment of the present invention, the laser power meter 6 is preferably a Gentec-EO HP100 series laser power meter, which is a key component for achieving accurate measurement of thermal load input and long-term system calibration.

[0059] In one embodiment of the present invention, the testing apparatus 100 further includes a water-cooling module for providing stable circulating heat dissipation for the laser generator 12 and the laser head 7. Specifically, the water-cooling module includes: The water chiller 3 and water cooling pipes are configured to form a complete closed-loop cooling path, with coolant circulating through the water cooling pipes to provide heat dissipation for the laser generator 12 and the laser head 7. A heat exchanger configured to connect to an external cold source (e.g., a chiller) and to achieve heat exchange with the coolant; and The temperature controller is configured to monitor the flow rate and temperature parameters of the coolant in real time, control the coolant temperature fluctuation within ±0.5℃ through closed-loop control, and monitor the flow rate and temperature parameters in real time to ensure that the laser system operates in a constant thermal environment, thereby ensuring the long-term stability of output power and beam quality.

[0060] In one embodiment of the invention, the power supply 13 is configured to provide stable power to devices such as the water chiller 3, the precision balance 5, the laser generator 12, and the computer 11. The power supply 13 is preferably a wide-input voltage (AC 220V±10%) power supply.

[0061] In one embodiment of the present invention, the testing device 100 further includes: A programmable interface is used to connect to a host computer (11), enabling programmed workflow arrangement and / or remote control. This allows for the programming and setting of complex heating power curves, heating times, and cycle sequences. The test device 100 can be set and / or operated manually via a local operation panel, allowing for quick setup and startup by directly inputting key parameters.

[0062] In one embodiment of the present invention, in terms of safety design, the testing device 100 includes multiple hardware interlocks and software limit protections, such as an emergency stop switch, protective cover linkage, and power threshold monitoring, to ensure that the laser output can be immediately cut off in abnormal conditions, effectively preventing any potential laser damage. In a specific embodiment of the present invention, multi-dimensional determination of laser activation is achieved based on signals collected by multiple types of sensors. The laser generator 12 can only be started when all determination conditions are met. The specific determination conditions include: The environment of the test bench is monitored in real time by vibration sensors to determine that the environment is stable and without vibration. The laser head's direct direction is monitored by infrared or visual sensors to ensure that no human hand or other biological tissue enters the direct-projection area; By collecting operational status data through the built-in sensors of each module, it is determined that all relevant modules, such as the laser generator, water cooling module, and calibration module, are operating normally. If any judgment condition is not met, the system will trigger a hardware interlock to cut off the laser start-up circuit and lock the laser output function through software limit to avoid the risk of laser radiation.

[0063] The invention proposes a system that can be divided into eight functional modules, specifically including: (1) A laser generating module configured to generate continuous or pulsed laser light. In one embodiment of the invention, the core of the laser generating module is a modular, water-cooled laser generator 12.

[0064] (2) A laser beam shaping module, optically connected to the laser generating module, wherein the laser beam shaping module is configured to shape the laser into a uniform spot and output it to the test area. In one embodiment of the present invention, the laser beam shaping module includes a homogenizing component and a lens module in the laser head 7.

[0065] (3) A sample clamping and weighing module is configured to clamp the test piece, so that the bottom of the test piece forms a wetting interface with the liquid working medium, and to record the evaporation mass of the liquid working medium in real time. In one embodiment of the present invention, the sample clamping and weighing module includes a precision balance 5, a sample clamping platform 9, and a liquid level maintaining device 10.

[0066] (4) A temperature measurement module configured to monitor the temperature distribution on the surface of the porous plate specimen under test in real time. In one embodiment of the present invention, the temperature measurement module includes an infrared thermal imager 8.

[0067] (5) A control module, electrically connected to the laser generating module, laser beam rectifier module, precision balance, and temperature measurement module, respectively. The control module is configured to control the testing process and synchronously collect data. In one embodiment of the present invention, the control module includes a local operation panel and a computer 11. The control module has both programmable and terminal control modes. The programmable control mode supports software programming control via the computer 11 (host computer), while the terminal control mode supports parameter setting and operation via the local operation panel. The control module also integrates safety protection functions including hardware interlocking and software limit switching. By collecting signals based on multiple types of sensors, it realizes multi-dimensional determination of laser activation, effectively reducing the risk of laser radiation.

[0068] (6) A calibration module is integrated into the output optical path of the laser generator module. The calibration module is configured to measure and calibrate the output laser power in real time.

[0069] (7) A water-cooling module configured to provide circulating cooling for the laser generating module and the laser beam rectifier module. In one embodiment of the present invention, the water-cooling module is an independent closed-loop cooling system, including a water chiller 3, water-cooling pipes, a heat exchanger and a temperature controller, for ensuring the stable and efficient operation of the laser generator 12 and the laser head 7.

[0070] (8) A power supply module configured to provide a stable power supply to each power-consuming unit in the device.

[0071] This invention also proposes a method for testing the thermal-mass coupling transport characteristics of porous plates, comprising the following steps: Step S100, Power-on initialization of the testing device: Unlock the universal casters 1 with locking function installed at the bottom of the profile frame 2, push the profile frame 2 to move the testing device 100 to the designated testing area, and lock the universal casters 1 to make the testing device 100 stable. Turn on the power supply 13, water chiller 3, computer 11, laser generator 12, infrared thermal imager 8 and precision balance 5 in sequence. After each component completes its self-test, the system power-on initialization is completed.

[0072] Step S200: Laser Power Calibration and Thermal Boundary Condition Establishment: The calibration program is initiated by computer 11. The laser output from laser generator 12 is transmitted to laser head 7 via optical fiber. Simultaneously, the beam splitter in the optical path guides a portion of the laser to laser power meter 6 integrated in the optical path. Laser power meter 6 samples and measures the actual output power of the laser, feeds the data back to computer 11 in real time, compares it with the preset target power, completes dynamic calibration, and establishes precise and controllable thermal boundary conditions.

[0073] Step S300, clamping and wetting interface establishment of the test specimen: Precisely fix the porous plate specimen to be tested at the center of the sample clamping platform 9, ensuring that the surface of the test specimen is aligned with the laser irradiation area. Activate the liquid level holding device 10 to inject liquid working medium under the test specimen. Through the liquid level control function of the liquid level holding device 10, precisely adjust the liquid level of the working medium so that the bottom of the test specimen is just immersed in the liquid working medium, forming a stable phase change wetting interface.

[0074] Step S400, Application of Thermal Load and Synchronous Data Acquisition: The computer 11 sends a test start command, and the laser generator 12 outputs laser light at the calibrated power. After being homogenized and shaped into a uniform spot by the laser head 7, the laser light is vertically irradiated onto the surface of the test piece to apply a thermal load. Simultaneously, the infrared thermal imager 8 and the precision balance 5 are activated. The infrared thermal imager 8 captures the changes in the surface temperature distribution of the test piece in real time and transmits the data to the computer 11. The precision balance 5 continuously monitors the overall mass change of the sample clamping platform 9, the test piece, and the liquid working fluid, thereby recording the mass loss data caused by the evaporation of the liquid working fluid and simultaneously uploading it to the computer 11.

[0075] Step S500, Data Processing and Characteristic Parameter Calculation: Computer 11 organizes and analyzes the collected temperature distribution data and mass change data. Based on the preset thermodynamic and mass transfer theoretical model, it calculates the thermal and mass transport characteristic parameters of the porous plate under test through data fusion algorithm. The characteristic parameters include the equivalent thermal conductivity and the phase change heat transfer coefficient, thus completing the quantitative characterization of the thermal and mass coupling transport characteristics of the porous plate.

[0076] Figure 6 The calculation process for equivalent thermal conductivity and phase change heat transfer coefficient in one embodiment of the present invention is shown.

[0077] like Figure 6 As shown, in one embodiment of the present invention, the calculation process for the equivalent thermal conductivity and phase change heat transfer coefficient can be summarized in the following three steps: Step S501, Temperature field data acquisition: The infrared thermal imager 8 converts the received radiation energy into a temperature field. .

[0078] Step S502: Establish a forward energy balance model: Under laser irradiation, energy input, conduction, convection, and phase change (evaporation) must satisfy energy conservation. Therefore, under laser heat load, the change in internal energy per unit volume of the porous plate is equal to the net heat transferred by heat conduction plus the heat provided by the internal heat source of the laser, expressed as: in, This indicates the equivalent density of the porous substrate. This indicates the specific heat capacity of the porous plate. This represents the equivalent thermal conductivity of the porous substrate. This represents the heat source term per unit volume corresponding to laser loading.

[0079] At the evaporation surface (z=0) of the porous plate, the energy balance equation is expressed as: in, This represents the laser input heat flux density; This represents the convective heat loss, which is the heat flux density lost between the evaporating surface and the surrounding environment through convective heat transfer. This represents heat radiation loss, specifically the heat flux density that is dissipated from the evaporating surface to the environment through heat radiation. This indicates the heat consumed during evaporation phase change, which is the heat flux density consumed when the liquid working fluid at the evaporation surface undergoes a phase change (evaporation).

[0080] Among them, the heat consumption of evaporation phase change It is the core term in the energy balance of the evaporation surface, representing the heat consumed per unit area and per unit time when the liquid working fluid at the evaporation surface undergoes a phase change, and is expressed as follows: in, Evaporation rate per unit area, expressed in kg / m² 2 ·s; The latent heat of vaporization of water is expressed in J / kg. Indicates the phase change heat transfer coefficient; This indicates the surface temperature, expressed in °C. This indicates the saturation temperature under the current pressure, typically 100°C or the corresponding boiling point in the environment.

[0081] S503, Parameter Inversion Calculation: Since the equivalent thermal conductivity and phase change heat transfer coefficient cannot be directly measured, they need to be inferred from the surface temperature field observed by the infrared thermal imager 8. Specifically, in one embodiment of the present invention: The predicted values ​​of the equivalent thermal conductivity and / or phase change heat transfer coefficient are provided and substituted into the model to obtain the numerical simulation temperature.

[0082] Define the sum of squared residuals between the measured temperature and the numerically simulated temperature as the objective function: in, This indicates the measured temperature, specifically the temperature obtained from the infrared thermal imager 8. This represents the numerical simulation temperature, i.e., the temperature calculated using the model described in step S502; M Indicates the total number of nodes in the space; N Indicates the total number of time collection points; The objective function is used to quantify the error between the measured temperature and the numerically simulated temperature after substituting the parameters: Objective function The smaller the value, the better the current... , The closer it is to the true value.

[0083] Calculate the sensitivity coefficient ,in For the heat transport characteristic parameters (in this embodiment, the calorific value transport characteristic parameters can be equivalent thermal conductivity and / or phase change heat transfer coefficient), determine the degree of response of temperature changes to changes in different heat transport characteristic parameters, thereby determining the adjustment priority and / or step size to assist in subsequent iterative solutions. If the sensitivity coefficient of a certain parameter is large, it indicates that the parameter has a more significant impact on temperature, and this parameter needs to be adjusted more finely during iteration to improve the solution accuracy.

[0084] Provide the equivalent thermal conductivity and / or phase change heat transfer coefficient The predicted value is obtained, and the predicted value is adjusted using an iterative optimization method, combining the objective function and the sensitivity coefficient. By repeatedly adjusting the equivalent thermal conductivity Phase change heat transfer coefficient The value of is substituted into the numerical simulation to obtain the numerical simulation temperature. Calculate the objective function ,judge A loop process is performed to check if the error is less than the threshold, until the objective function is achieved. The equivalent thermal conductivity is minimized when the measured temperature is minimized (i.e., the error between the measured and simulated temperatures is sufficiently small) or when the parameter change meets the convergence requirement. and / or phase change heat transfer coefficient These are the final parameters obtained from parameter inversion calculation.

[0085] In one embodiment of the present invention, after the test is completed, the devices in the test device 100 are turned off in the reverse order of the start-up order: all measuring devices (precision balance 5 and infrared thermal imager 8), laser generator 12, computer 11, water chiller 3 and power supply 13.

[0086] Although various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A device for testing the thermal-mass coupling transport characteristics of porous plates, characterized in that, The device includes: Profile frame; A laser head, which is movably arranged on the profile frame and configured to emit a laser to irradiate a test piece, wherein the test piece is a porous plate. A laser power meter, which is movably arranged on a profile frame and configured to measure the power of the laser emitted by the laser head; A precision balance configured to detect changes in the mass of the test piece; A sample clamping platform is arranged on the precision balance and configured to hold the sample to be tested. A liquid level maintaining device is disposed on one side of the sample clamping platform, connected to the sample clamping platform, and configured to adjust or maintain the liquid level of the liquid working fluid; and An infrared thermal imager is configured to visualize the temperature field distribution on the surface of the test piece.

2. The apparatus according to claim 1, characterized in that, The device further includes: A laser generator is arranged on the profile frame and coupled to the laser head via an optical fiber. The laser generator is configured to generate continuous or pulsed laser light. A variable-layout mounting bracket is arranged on the profile frame and configured to support the laser head, laser power meter, and precision balance. The computer is electrically connected to the laser generator, laser power meter, precision balance and infrared thermal imager respectively; The power supply is arranged on the profile frame and is electrically connected to the laser generator, laser power meter, precision balance, infrared thermal imager and computer; A programmable interface, configured to connect to a host computer for programmed workflow arrangement and / or remote control; and A local operation panel is configured to perform manual parameter settings and / or operations on the device.

3. The apparatus according to claim 2, characterized in that, The variable layout mounting bracket includes: The precision balance, sample clamping platform, and liquid level maintaining device are all arranged on the support platform. A column, fixedly connected to the supporting platform and perpendicular to the surface of the supporting platform; and The bracket is movably connected to the column by locking bolts. The bracket can move along the length of the column to adjust its height, and the bracket can rotate around the column to adjust its orientation. The bracket includes a first bracket and a second bracket. The laser power meter is arranged on the first bracket, and the laser head and the infrared thermal imager are arranged on the second bracket.

4. The apparatus according to claim 2, characterized in that, The laser head includes a homogenization component and a lens module, wherein: The homogenization component and lens module integrate the processing of the laser generated by the laser generator and output a square flat-top light spot. The size of the light spot can be adjusted by replacing the lens module.

5. The apparatus according to claim 1, characterized in that, The sample clamping platform is equipped with multiple sets of limiters of different sizes, including: Each set of limiters includes four clamping columns arranged symmetrically about the center of the sample clamping platform. Each clamping column is provided with a groove, and the test piece is fixedly clamped in the grooves of the four clamping columns.

6. The apparatus according to claim 1, characterized in that, The liquid level maintaining device includes: A liquid storage container is constructed as a closed container to store liquid working fluid; The liquid level control area is connected to the sample clamping platform, forming a communicating vessel; A miniature peristaltic pump, connected in series between the liquid storage container and the liquid level control zone, is configured to transport the liquid working fluid from the liquid storage container to the liquid level control zone; and A baffle is arranged on one side of the liquid level control area, the height of the baffle is adjustable, and it is configured to control the liquid level height of the liquid level control area.

7. The apparatus according to claim 1, characterized in that, The device further includes a water-cooling module electrically connected to the computer and the power supply, wherein the water-cooling module comprises: The water chiller and water cooling pipes are configured to form a complete closed-loop cooling path, through which the coolant circulates to provide heat dissipation for the laser generator and the laser head. A heat exchanger configured to connect to an external cold source and to achieve heat exchange with the coolant; and A thermostat is configured to monitor the flow rate and temperature parameters of the coolant in real time and limit coolant temperature fluctuations within a preset range through closed-loop control.

8. The apparatus according to claim 1 or 7, characterized in that, The profile frame is an aluminum alloy profile frame, and its bottom is equipped with casters with locking mechanisms, wherein: The profile frame has a double-layer structure, with the power supply and the water chiller arranged at the bottom layer of the profile frame, and the remaining components of the device arranged at the top layer of the profile frame.

9. A method for testing the thermal-mass coupling transport characteristics of porous plates, characterized in that, The method, using the apparatus according to any one of claims 1-8, comprises: Place the device stably and lock it using the casters, then turn on the power supply, water chiller, computer, laser generator, infrared thermal imager, and precision balance in sequence to complete the power-on initialization. The laser output power is calibrated using the laser power meter to establish thermal boundary conditions; The porous plate test specimen is fixed to the center of the sample clamping platform by a limiter. The liquid level maintaining device is used to inject liquid working medium into the sample clamping platform and the liquid level height is adjusted by adjusting the baffle of the liquid level maintaining device so that the bottom of the test specimen is just immersed in the liquid working medium. The laser generator is activated, outputting a laser beam that irradiates the surface of the test piece to apply a thermal load. Simultaneously, the surface temperature distribution of the test piece is recorded using an infrared thermal imager, and the mass change of the test piece is recorded using a precision balance. Based on the collected temperature distribution data and mass change data, the thermal and mass transport characteristics parameters of the test piece are calculated.

10. The method according to claim 9, characterized in that, The heat and mass transport characteristics parameters include the equivalent thermal conductivity and / or the phase change heat transfer coefficient.

11. The method according to claim 10, characterized in that, The calculation of the equivalent thermal conductivity and phase change heat transfer coefficient includes: The radiant energy from the surface of the test piece acquired by the infrared thermal imager is converted into a surface temperature field. ; A three-dimensional heat conduction model is provided, including the laser heat source and phase change heat dissipation, with the governing equations as follows: in, Indicates the equivalent density of the test specimen; This indicates the specific heat capacity of the test specimen; This represents the equivalent thermal conductivity of the test piece; This represents the heat source term per unit volume corresponding to laser loading; The boundary conditions for the evaporation surface of the test piece are provided, and its energy balance equation is as follows: in, This represents the laser input heat flux density; This indicates convective heat transfer loss; Indicates heat radiation loss; This indicates that the evaporation phase change consumes heat; The heat consumption of the evaporation phase change is expressed as: in, Indicates the phase change heat transfer coefficient; Indicates the surface temperature of the test piece; Indicates the saturation temperature under the current pressure; and According to the heat conduction model, the equivalent thermal conductivity and / or phase change heat transfer coefficient are obtained by parameter inversion calculation from the surface temperature field.

12. The method according to claim 11, characterized in that, The parameter inversion calculation includes: The predicted values ​​of the equivalent thermal conductivity and / or phase change heat transfer coefficient are provided and substituted into the heat conduction model to calculate the numerical simulation temperature. Based on the measured temperature of the temperature field, the objective function is defined as follows: in, Indicates the measured temperature; This represents the temperature in the numerical simulation. M Indicates the total number of nodes in the space; N Indicates the total number of time collection points; Provide sensitivity coefficient ,in These are heat and mass transport characteristic parameters; the degree of responsiveness of these parameters to changes in temperature is determined; and The predicted values ​​are adjusted using an iterative optimization method, and the priority and / or step size of the iterative adjustment of parameters are determined by combining the sensitivity coefficient, until the objective function is achieved. If the value is less than the preset threshold or the parameter change meets the convergence requirements, the final equivalent thermal conductivity and / or phase change heat transfer coefficient will be output.

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