Contact angle characterization device and method for accurate temperature control coupling measurement in multi-gas atmosphere

Abstract

The invention relates to the technical field of thermophysical measurement and surface characteristic characterization, in particular to a contact angle characterization device and method for accurate temperature control coupling measurement in a multi-gas atmosphere. The contact angle characterization device comprises a precise temperature control module, a contact angle dynamic measurement module, a laser-induced fluorescence measurement module and a gas atmosphere regulation and control module, the precise temperature control module comprises an experiment main body, an air pipe interface, a Peltier element array, a thermal insulation material, a thermocouple, a main body data acquisition instrument and a heat dissipation structure, pressure-resistant glass windows are arranged on two sides of the experiment main body, the air pipe interface is arranged above the experiment main body, the thermal insulation material partially extends into the experiment main body, the Peltier element array is arranged on the thermal insulation material, and the thermocouple is arranged on the main body data acquisition instrument. And the air pipe connector corresponds to the air pipe connector. Accurate test surface temperature control and rapid temperature response can be realized, the gas atmosphere and test pressure can be changed more conveniently by using the gas atmosphere regulation and control module, more complex experiment conditions are realized, and the system is closer to the actual application process.

Description

Technical Field

[0001] This invention relates to the field of thermophysical measurement and surface characterization technology, specifically to a contact angle characterization device and method for precise temperature-controlled coupled measurement under multi-gas atmosphere. Background Technology

[0002] Surface properties have a significant impact on phase change heat transfer processes such as boiling, evaporation, and condensation. The wetting process of droplets on heat transfer surfaces is a fundamental issue in energy engineering, interface physics, and materials science. The contact angle of a droplet directly reflects the mechanical equilibrium state and energy characteristics of the gas-liquid-solid three-phase interface, as well as the wetting properties of the heat transfer surface. Studying the dynamic changes in droplet contact angles on different heat transfer surfaces can not only reveal the mechanisms by which surface microstructure and chemical composition affect wetting performance, but also has important implications for enhancing heat transfer processes.

[0003] Meanwhile, studying the dynamic changes in droplet contact angle under complex environments has crucial guiding significance for fields such as heat dissipation of electronic devices, phase change energy storage, fuel combustion, and spray cooling. However, current research on the dynamic characterization of droplet contact angle under complex environments still relies on traditional angle measuring instruments and environmental cavity systems, which suffer from temperature control lag and limited measurement dimensions, making it difficult to accurately measure the heat and mass transfer behavior on heat exchange surfaces under real-world operating conditions. Therefore, there is an urgent need to construct an experimental platform for the dynamic characterization of droplet contact angle that can rapidly control surface temperature and dynamically and accurately measure it under a controlled gas atmosphere, providing theoretical basis and practical guidance for the development of efficient heat exchange surface design and multiphysics coupled heat transfer models.

[0004] Existing droplet contact angle testing devices mostly use CCD cameras to capture droplet morphology and calculate the contact angle, failing to reveal the internal temperature field, flow pattern, and thermal driving mechanism of the droplet. Temperature regulation relies on resistance wire heating or circulating water temperature control, which has a certain response time delay, making it difficult to meet more precise testing requirements. Furthermore, most systems cannot achieve different gas atmospheres and dynamic pressure control, resulting in significant deviations between experimental conditions and actual operating conditions. In summary, existing droplet contact angle characterization techniques on heat exchange surfaces have certain shortcomings in terms of gas atmosphere adjustability, temperature control accuracy and response speed, and synchronization with advanced multimodal measurement technologies. There is an urgent need to develop a dynamic characterization device for droplet contact angles on heat exchange surfaces that integrates multi-gas atmosphere control, rapid and accurate temperature control, and advanced optical measurement. This device would enable real-time dynamic visualization characterization and testing of droplet contact angles during phase change heat transfer on heat exchange surfaces under complex gas atmospheres, providing systematic experimental support for multiphase interface heat and mass transfer research, providing a solid experimental system for clarifying the phase change heat transfer enhancement mechanism of different heat exchange surfaces, and further promoting the efficient and widespread application of phase change heat transfer technology. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problems of low temperature control accuracy, slow response speed, uncontrollable gas atmosphere and single measurement method in the existing heat exchange surface droplet contact angle measurement device, so as to provide a contact angle characterization device and method for accurate temperature control coupling measurement under multiple gas atmospheres.

[0006] To address the aforementioned technical problems, this invention provides a contact angle characterization device for precise temperature control and coupled measurement under multi-gas atmospheres, comprising a precise temperature control module, a contact angle dynamic measurement module, a laser-induced fluorescence measurement module, and a gas atmosphere regulation module. The precise temperature control module includes an experimental body and a gas pipe interface, a Peltier element array, insulation material, thermocouples, a main data acquisition unit, and a heat dissipation structure. The experimental body has pressure-resistant glass windows on both sides, the gas pipe interface is located above the experimental body, the insulation material partially extends into the experimental body, and the Peltier element array is disposed on the insulation material. Corresponding to the tracheal interface, a thermocouple is provided on the insulation material, which is connected to the main data acquisition instrument, and a heat dissipation structure is provided within the insulation material; a contact angle dynamic measurement module and a laser-induced fluorescence measurement module are set corresponding to the pressure-resistant glass window, and the contact angle dynamic measurement module and the laser-induced fluorescence measurement module are coupled to form an optical measurement system to characterize the evolution of droplet morphology on the heat exchange surface of the Peltier element array, and related information on the internal temperature field and flow field of the droplets; a gas atmosphere control module is connected to the tracheal interface to provide a gas atmosphere and ensure experimental safety.

[0007] Furthermore, the Peltier element array consists of a semiconductor cooling chip and a heating wire, wherein the cooling capacity of the semiconductor cooling chip is 100W and the power of the heating wire is 200W.

[0008] Furthermore, the experimental body includes a stainless steel support and a stainless steel housing, with the main pressure gauge mounted on the stainless steel housing.

[0009] Furthermore, the heat dissipation structure includes a heat dissipation block and a cooling fan, the heat dissipation block being disposed within the insulation material, and the cooling fan being disposed on both sides of the insulation material.

[0010] Furthermore, the heat sink has aluminum heat dissipation fins, and the heat sink is connected to the Peltier element array via thermally conductive silicone grease with a thermal conductivity of 8.5 W / mK.

[0011] Furthermore, the precision temperature control module also includes a programmable power supply and a computer, the computer being connected to the programmable power supply, the main data acquisition unit, and the heat dissipation structure.

[0012] Furthermore, the contact angle dynamic measurement module includes a CCD camera and a dynamic data acquisition device, with the pressure-resistant glass window on one side of the CCD camera, and the dynamic data acquisition device connected to the CCD camera.

[0013] Furthermore, the laser-induced fluorescence measurement module includes a laser and a lens, a beam shaper, a first reflector, a second reflector, a spectrometer, and a fluorescence data acquisition instrument. The first and second reflectors are set corresponding to the pressure-resistant glass window. The spectrometer is connected to the fluorescence data acquisition instrument. The laser is set corresponding to the first reflector. The lens and beam shaper are set on the laser path of the laser. The laser generates a laser beam, which is then processed by the lens and beam shaper to generate a measurable laser beam. The laser beam is adjusted by the first reflector and enters the test area. After acquiring the required information, it is reflected by the second reflector into the spectrometer. Finally, the information is recorded by the fluorescence data acquisition instrument.

[0014] Furthermore, the gas atmosphere control module includes an intake pressure gauge and an intake storage tank, an intake pipe, an intake flow meter, an intake valve, an exhaust valve, an exhaust flow meter, an exhaust pipe, a gas-liquid separator, an intake storage tank, and an intake pressure gauge. Both the intake pipe and the exhaust pipe are connected to a gas pipe interface. The intake pipe is sequentially equipped with an intake pressure gauge, an intake storage tank, an intake flow meter, and an intake valve. The exhaust pipe is sequentially equipped with an exhaust valve, an exhaust flow meter, a gas-liquid separator, an intake storage tank, and an intake pressure gauge.

[0015] The present invention also provides a method for operating the contact angle characterization device using the aforementioned multi-gas atmosphere precise temperature control coupling measurement, which includes the following steps: Step 1: Check the airtightness of the device, connect all the pipes, place the heat exchange surface to be tested on the Peltier element array, adjust the power to achieve rapid heating or cooling, and combine the thermocouple, main data acquisition instrument, and heat dissipation structure with computer control to achieve real-time temperature feedback and adjustment to adjust the temperature to the required test requirements. Step 2: The contact angle dynamic measurement module is coupled with the laser-induced fluorescence measurement module to test the entire droplet contact angle change process. The droplet to be measured is fluorescently marked. The contact angle dynamic measurement module dynamically records the contact angle change, adjusts the laser power and the reflector angle to ensure that the beam passes through the test area, obtains the overall temperature field and flow information, and further couples and corrects to form a more accurate contact angle measurement result. Step 3: Adjust the gas entering the experimental body, monitor the pressure values ​​at various points in real time, control the gas discharge, and combine the gas intake and exhaust processes to adjust the pressure inside the experimental body in real time, so as to realize the contact angle test process under complex environments such as different pressures.

[0016] The technical solution of this invention has the following advantages: 1. The contact angle characterization device for precise temperature control coupled measurement under multi-gas atmosphere provided by the present invention includes a precise temperature control module, a contact angle dynamic measurement module, a laser-induced fluorescence measurement module, and a gas atmosphere control module; the precise temperature control module includes an experimental body and a gas tube interface, a Peltier element array, thermal insulation material, a thermocouple, a main data acquisition instrument, and a heat dissipation structure; the experimental body is provided with pressure-resistant glass windows on both sides, the gas tube interface is located above the experimental body, the thermal insulation material partially extends into the experimental body, and the Peltier element array is located on the thermal insulation material and is coupled with the gas tube. Corresponding to the interface, a thermocouple is provided on the insulation material, which is connected to the main data acquisition instrument, and a heat dissipation structure is provided within the insulation material; a contact angle dynamic measurement module and a laser-induced fluorescence measurement module are set corresponding to the pressure-resistant glass window, and the contact angle dynamic measurement module and the laser-induced fluorescence measurement module are coupled to form an optical measurement system to characterize the evolution of droplet morphology on the heat exchange surface of the Peltier element array and related information of the internal temperature field and flow field of the droplet; a gas atmosphere control module is connected to the gas pipe interface to provide a gas atmosphere and ensure experimental safety.

[0017] This precise temperature control module serves as the foundation of the main experimental process, providing a closed environment and enabling both heating and cooling. A gas pipe interface on the main experimental unit facilitates connection to the gas atmosphere control module, allowing gas to be delivered into the experimental unit and removed after the experiment, ensuring experimental safety. During the experiment, the gas pipe interface is opened, and droplets are dropped onto the heat exchange surface of the Peltier element array. Data is collected using thermocouples and the main unit's data acquisition instrument, while precise temperature control is achieved in conjunction with the heat dissipation structure. An optical measurement system is then formed by coupling a contact angle dynamic measurement module and a laser-induced fluorescence measurement module to characterize the droplet morphology evolution on the heat exchange surface of the Peltier element array, along with related information on the internal temperature and flow fields of the droplets.

[0018] This contact angle characterization device, employing precise temperature control and coupled measurement under multi-gas atmospheres, enables accurate temperature control and rapid temperature response of the test surface. The gas atmosphere control module allows for easier alteration of the gas atmosphere and test pressure, facilitating more complex experimental conditions and closely mirroring real-world applications. Combining CCD imaging and laser-induced fluorescence technology, it simultaneously acquires droplet morphology evolution and internal temperature fields, achieving spatial interaction and temporal synchronization of multi-scale information. This solves the problem of traditional testing methods being unable to record detailed changes in droplet contact angles from multiple dimensions. Each functional module is independently designed and can be quickly replaced or expanded. This device provides a high-precision experimental platform for studying the microscopic heat transfer mechanisms of heat transfer surfaces.

[0019] This contact angle characterization device, employing precise temperature control and coupled measurement in a multi-gas atmosphere, proposes a dynamic characterization device for droplet contact angles on heat exchange surfaces. It integrates rapid and precise temperature control, gas atmosphere regulation, and multimodal optical measurement, overcoming the technical bottlenecks of traditional systems such as hysteresis in temperature response and limited measurement dimensions. This provides an advanced characterization and testing technique for the dynamic measurement of droplet contact angles on heat exchange surfaces, achieving full-field visualization of the droplet's shape and internal temperature field. It provides theoretical guidance for revealing the dynamic mechanism of liquid phase transition processes on heat exchange surfaces under complex environmental conditions, and offers a novel experimental platform and technical means for research in fields such as heat transfer enhancement and surface engineering.

[0020] 2. The contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere provided by this invention comprises a Peltier element array consisting of a semiconductor cooling chip and a heating wire. The cooling capacity of the semiconductor cooling chip is 100W, and the power of the heating wire is 200W. The cooling and heating processes are achieved by controlling the direction of the current using the Peltier effect. The 200W heating wire provides auxiliary heating, enabling the heat exchange surface to heat up rapidly.

[0021] 3. The contact angle characterization device for precise temperature control coupled measurement under multi-gas atmosphere provided by the present invention includes a contact angle dynamic measurement module comprising a CCD camera and a dynamic data acquisition instrument. The pressure-resistant glass window is positioned on one side of the CCD camera, and the dynamic data acquisition instrument is connected to the CCD camera. The CCD camera dynamically records the changes in droplet morphology on the heat exchange surface, and the dynamic data acquisition instrument records this data in a computer. The two-dimensional image of the droplet is analyzed, and the contact angle of the droplet is calculated using geometric methods.

[0022] The summary section is provided to present the chosen concepts in a simplified form, which will be further described in the detailed description below. The summary section is not intended to identify essential or necessary features of this disclosure, nor is it intended to limit the scope of this disclosure. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere provided by the present invention.

[0025] Explanation of reference numerals in the attached figures: 1. Stainless steel bracket; 2. Stainless steel housing; 3. First pressure-resistant glass window; 4. Main pressure gauge; 5. Gas pipe interface; 6. Second pressure-resistant glass window; 7. Peltier element array; 8. Thermocouple; 9. Main data acquisition unit; 10. Insulation material; 11. Heat sink; 12. Cooling fan; 13. Programmable power supply; 14. Computer; 15. CCD camera; 16. Dynamic data acquisition unit; 17. Laser; 18. Lens; 19. Beam shaper; 20. First reflector; 21. Second reflector; 22. Spectrometer; 23. Fluorescence data acquisition unit; 24. Inlet pressure gauge; 25. Inlet air storage tank; 26. Inlet pipe; 27. Inlet flow meter; 28. Inlet valve; 29. ​​Exhaust valve; 30. Exhaust flow meter; 31. Exhaust pipe; 32. Gas-liquid separator; 33. Exhaust air storage tank; 34. Exhaust pressure gauge. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0027] The preferred embodiments of this disclosure are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0028] Please see Figure 1 As shown, this invention provides a contact angle characterization device for precise temperature control coupled measurement under multi-gas atmospheres, including a precise temperature control module, a dynamic contact angle measurement module, a laser-induced fluorescence measurement module, and a gas atmosphere control module. The precise temperature control module enables rapid temperature response control. The dynamic contact angle measurement module enables dynamic and precise measurement of the contact angle. The laser-induced fluorescence measurement module characterizes the temperature field distribution of the droplet and further corrects the contact angle testing process. The gas atmosphere control module enables accurate control of the gas atmosphere.

[0029] The precise temperature control module includes an experimental body and a gas pipe interface 5, a Peltier element array 7, insulation material 10, thermocouples 8, a main data acquisition instrument 9, and a heat dissipation structure. The experimental body has pressure-resistant glass windows on both sides. The gas pipe interface 5 is located above the experimental body. Part of the insulation material 10 extends into the experimental body. The Peltier element array 7 is located on the insulation material 10 and corresponds to the gas pipe interface 5. Thermocouples 8 are located on the insulation material 10 and connected to the main data acquisition instrument 9. A heat dissipation structure is located within the insulation material 10. A contact angle dynamic measurement module and a laser-induced fluorescence measurement module are positioned corresponding to the pressure-resistant glass windows. These modules are coupled to form an optical measurement system to characterize the droplet morphology evolution on the heat exchange surface of the Peltier element array 7 and related information about the internal temperature and flow fields of the droplets. A gas atmosphere control module, connected to the gas pipe interface 5, is used to provide the gas atmosphere and ensure experimental safety.

[0030] This precise temperature control module serves as the foundation of the main experimental process, providing a closed environment and enabling both heating and cooling. A gas pipe interface 5 is installed on the main experimental unit, facilitating its connection to the gas atmosphere control module. This allows for the delivery of gas into the experimental unit and its removal after the experiment, ensuring experimental safety. During the experiment, the gas pipe interface 5 is opened, and droplets are introduced onto the heat exchange surface of the Peltier element array 7. Data is collected using thermocouples 8 and the main data acquisition instrument 9, while precise temperature control is achieved in conjunction with the heat dissipation structure. An optical measurement system is then formed by coupling a contact angle dynamic measurement module and a laser-induced fluorescence measurement module to characterize the droplet morphology evolution on the heat exchange surface of the Peltier element array 7, along with related information on the internal temperature and flow fields of the droplets.

[0031] This contact angle characterization device, employing precise temperature control and coupled measurement under multi-gas atmospheres, enables accurate temperature control and rapid temperature response of the test surface. The gas atmosphere control module allows for easier alteration of the gas atmosphere and test pressure, facilitating more complex experimental conditions and closely mirroring real-world applications. Combining CCD imaging and laser-induced fluorescence technology, it simultaneously acquires droplet morphology evolution and internal temperature fields, achieving spatial interaction and temporal synchronization of multi-scale information. This solves the problem of traditional testing methods being unable to record detailed changes in droplet contact angles from multiple dimensions. Each functional module is independently designed and can be quickly replaced or expanded. This device provides a high-precision experimental platform for studying the microscopic heat transfer mechanisms of heat transfer surfaces.

[0032] This contact angle characterization device, employing precise temperature control and coupled measurement under multi-gas atmospheres, proposes a dynamic characterization device for the contact angle of droplets on heat transfer surfaces. It integrates rapid and precise temperature control, gas atmosphere regulation, and multimodal optical measurement, overcoming the technical bottlenecks of traditional systems such as hysteresis in temperature response and limited measurement dimensions. This device achieves full-field visualization of the droplet's shape and internal temperature field. It provides theoretical guidance for revealing the dynamic mechanism of liquid phase transition processes on heat transfer surfaces under complex environmental conditions, and offers a novel experimental platform and technical means for research in fields such as heat transfer enhancement and surface engineering.

[0033] The gas can be nitrogen, carbon dioxide, argon, etc., and can be adjusted according to the actual situation.

[0034] The temperature of the heat exchange surface, i.e. the heating surface or the cooling surface, of the Peltier element array 7 is measured by thermocouples 8 and recorded by the main data acquisition instrument 9. The thermocouples 8, which are symmetrically distributed on both sides, can be used to reduce experimental errors. In addition, the setting of the insulation material 10 protects the temperature control process from external environmental interference.

[0035] In some optional embodiments, the Peltier element array 7 consists of a thermoelectric cooler and a heating wire, wherein the thermoelectric cooler has a cooling capacity of 100W and the heating wire has a power of 200W.

[0036] The cooling and heating processes are achieved by adjusting the direction of the current using the Peltier effect. The 200W heating wire provides auxiliary heating, which rapidly raises the temperature of the heat exchange surface.

[0037] The experimental body includes a stainless steel support 1 and a stainless steel shell 2, with the main pressure gauge 4 mounted on the stainless steel shell 2.

[0038] A stainless steel support frame 1 supports the overall experimental platform. A stainless steel shell 2 is mounted on the stainless steel support frame 1. A first pressure-resistant glass window 3 and a second pressure-resistant glass window 6 are located on both sides of the stainless steel shell 2. The first pressure-resistant glass window 3 and the second pressure-resistant glass window 6 have a bending strength of 150 MPa and a coefficient of thermal expansion of 3 × 10⁻⁶. -6 The first pressure-resistant glass window 3 and the second pressure-resistant glass window 6, together with the stainless steel housing 2, constitute a closed experimental testing environment. The main pressure gauge 4 is located on the top of the stainless steel housing 2 and is used to monitor pressure changes within the experimental body.

[0039] In some optional embodiments, the heat dissipation structure includes a heat sink 11 and a cooling fan 12. The heat sink 11 is disposed within the insulation material 10, and the cooling fan 12 is disposed on both sides of the insulation material 10. The heat sink 11 has aluminum heat dissipation fins and is connected to the Peltier element array 7 via thermally conductive silicone grease with a thermal conductivity of 8.5 W / mK.

[0040] The precision temperature control module also includes a programmable power supply 13 and a computer 14, wherein the computer 14 is connected to the programmable power supply 13, the main data acquisition instrument 9, and the heat dissipation structure.

[0041] The computer 14 controls the cooling fan 12 and the power of the input Peltier element array 7 in real time to stabilize the experimental test temperature within the required range.

[0042] The programmable power supply 13 is used to provide power, and its maximum power is 2000W. In some optional embodiments, the contact angle dynamic measurement module includes a CCD camera 15 and a dynamic data acquisition device 16, wherein the CCD camera 15 is disposed corresponding to the first pressure-resistant glass window 3, and the dynamic data acquisition device 16 is connected to the CCD camera 15.

[0043] The morphological changes of droplets on the heat exchange surface are dynamically recorded by a CCD camera 15 and recorded in a computer 14 by a dynamic data acquisition instrument 16. The two-dimensional image of the droplets is analyzed and the contact angle of the droplets is calculated using a geometric method.

[0044] The compact CCD camera 15 has advantages such as resistance to strong light, vibration and low distortion. The droplet morphology recorded by the camera in real time is used to calculate the dynamic contact angle change of the droplet through image analysis technology. The CCD camera 15 has a resolution of 2048×2048.

[0045] In some optional embodiments, the laser-induced fluorescence measurement module includes a laser 17, a lens 18, a beam shaper 19, a first reflector 20, a second reflector 21, a spectrometer 22, and a fluorescence data acquisition instrument 23. The first reflector 20 and the second reflector 21 are set to correspond to the pressure-resistant glass window, that is, the first reflector 20 is set to correspond to the second pressure-resistant glass window, and the second reflector 21 is set to correspond to the first pressure-resistant glass window. The spectrometer 22 is connected to the fluorescence data acquisition instrument 23. The laser 17 is set to correspond to the first reflector 20. The lens 18 and the beam shaper 19 are set on the laser path of the laser 17. The laser 17 generates a laser beam, which is then converted into a measurable laser beam by the lens 18 and the beam shaper 19. The laser beam is adjusted by the first reflector 20 to enter the test area. After obtaining the required information, it is reflected by the second reflector 21 into the spectrometer 22. Finally, the information is recorded by the fluorescence data acquisition instrument 23.

[0046] Laser is generated by laser 17, and the lens 18 and beam shaper 19 can focus the laser and filter stray light. The laser beam is controlled by the angle of the first reflector 20 to control the test range of the beam. After the laser causes the atoms or molecules in the marked droplet to absorb energy, they transition from the ground state to an unstable excited state and release energy in the form of fluorescence when returning to the ground state. The fluorescence signal is collected and reflected by the second reflector 21 into the spectrometer 22. The spectrometer 22 is used to analyze the information. Finally, the information is recorded by the fluorescence data acquisition instrument 23 and converted into temperature distribution using the calibration curve. The temperature field information of the droplet is obtained through colorimetric calibration and temperature field inversion algorithm, realizing the measurement and characterization of the internal temperature field of the droplet.

[0047] In some optional embodiments, the gas atmosphere control module includes an inlet pressure gauge 24 and an inlet storage tank 25, an inlet pipe 26, an inlet flow meter 27, an inlet valve 28, an exhaust valve 29, an exhaust flow meter 30, an exhaust pipe 31, a gas-liquid separator 32, an inlet storage tank 25, and an inlet pressure gauge 24. The inlet pipe 26 and the exhaust pipe 31 are both connected to the gas pipe interface 5. The inlet pipe 26 is sequentially equipped with an inlet pressure gauge 24, an inlet storage tank 25, an inlet flow meter 27, and an inlet valve 28. The exhaust pipe 31 is sequentially equipped with an exhaust valve 29, an exhaust flow meter 30, a gas-liquid separator 32, an inlet storage tank 25, and an inlet pressure gauge 24.

[0048] The inlet pressure gauge 24 displays the pressure of the inlet storage tank 25. The inlet valve 28 is opened to discharge the required gas into the experimental body through the inlet pipe 26. During the experiment, the exhaust valve 29 is adjusted to control the entire exhaust process. The gas is passed through the exhaust pipe 31 into the gas-liquid separator 32 and stored in the exhaust storage tank 33. The exhaust pressure gauge 34 displays the pressure of the exhaust storage tank 33. The inlet flow meter 27 and the exhaust flow meter 30 display the rate for more precise control.

[0049] The present invention also provides a method for operating the contact angle characterization device using the aforementioned multi-gas atmosphere precise temperature control coupling measurement, which includes the following steps: Step 1: Check the airtightness of the device, connect all the pipes, place the heat exchange surface to be tested on the Peltier element array 7, adjust the power to achieve rapid heating or cooling process, and combine the thermocouple 8, the main data acquisition instrument 9, and the heat dissipation structure with the computer 14 to achieve real-time temperature feedback and adjustment to adjust the temperature to the required test requirements. Step 2: The contact angle dynamic measurement module is coupled with the laser-induced fluorescence measurement module to test the entire droplet contact angle change process. The droplet to be measured is fluorescently marked. The contact angle dynamic measurement module dynamically records the contact angle change, adjusts the laser power and the reflector angle to ensure that the beam passes through the test area, obtains the overall temperature field and flow information, and further couples and corrects to form a more accurate contact angle measurement result. Step 3: Adjust the gas entering the experimental body, monitor the pressure values ​​at various points in real time, control the gas discharge, and combine the gas intake and exhaust processes to adjust the pressure inside the experimental body in real time, so as to realize the contact angle test process under complex environments such as different pressures.

[0050] Before the experiment, the cleaned heat exchange surface was fixed in the center of the Peltier element array 7 platform. The Peltier element array 7 was regulated by a real-time feedback temperature control system. Using a pipette, 8 μL of water containing a fluorescent tracer (1 × 10⁻⁶ concentration) was placed on the heat exchange surface. -5 The experimental chamber was pre-evacuated with nitrogen gas (mol / L). The pressure was regulated via the exhaust system. The CCD camera 15 and the laser excitation system were started synchronously. The CCD camera 15 viewed the droplet profile from the side for dynamic contact angle measurement, while the laser beam entered from the rear side of the droplet, forming a planar light field of approximately 100 μm thickness through an optical shaping system to illuminate the droplet cross-section, achieving transient fluorescence excitation of the internal temperature field of the droplet. The contact angle of the droplet was calculated using edge recognition and least-squares fitting. The calculation formula is:

[0051] In the formula, i The contact angle of the droplet is (°). h The droplet height is in meters (m). r Let the droplet base radius be (m). An improved Young-Laplace curve fitting model is used:

[0052] In the formula, x Let be the horizontal coordinate (m) of the droplet cross-section. y The height of the droplet surface (m). day / dx The slope of the tangent to the droplet profile. r Liquid density (kg / m³) 3 ), g Acceleration due to gravity (m / s²) 2 ), s The interfacial tension is denoted as N / m. d 2 y / dx2 Given the droplet curvature (1 / m), a theoretical curve that best matches the experimental droplet morphology was obtained by numerical integration from the droplet top. This further refined the solution process for the droplet contact angle, making the solution more accurate. By constructing an integrated experimental system for precise temperature control coupled with laser-induced fluorescence and dynamic contact angle measurement under multi-gas atmospheres, dynamic contact angle measurement of droplets on heat exchange surfaces in a real and complex environment was achieved. This provides crucial experimental support for studying the mechanisms of heat conduction and surface energy regulation, and promotes the application of heat exchange surfaces in multiple fields such as heat dissipation of electronic devices.

[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A contact angle characterization device for precise temperature control coupled measurement in a multi-gas atmosphere, characterized in that, It includes a precision temperature control module, a contact angle dynamic measurement module, a laser-induced fluorescence measurement module, and a gas atmosphere control module; The precision temperature control module includes an experimental body and a tracheal interface (5), a Peltier element array (7), insulation material (10), a thermocouple (8), a main data acquisition instrument (9), and a heat dissipation structure. The experimental body has pressure-resistant glass windows on both sides. The tracheal interface (5) is located above the experimental body. The insulation material (10) extends into the experimental body. The Peltier element array (7) is located on the insulation material (10) and corresponds to the tracheal interface (5). Thermocouples (8) are located on the insulation material (10). Thermocouples (8) are connected to the main data acquisition instrument (9). A heat dissipation structure is located inside the insulation material (10). The contact angle dynamic measurement module and the laser-induced fluorescence measurement module are set with a pressure-resistant glass window. The contact angle dynamic measurement module and the laser-induced fluorescence measurement module are coupled to form an optical measurement system to characterize the evolution of droplet morphology on the heat transfer surface of the Peltier element array (7) and related information of the internal temperature field and flow field of the droplet. The gas atmosphere control module is connected to the gas pipe interface (5) to provide gas atmosphere and ensure experimental safety.

2. The contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere as described in claim 1, characterized in that, The Peltier element array (7) consists of a semiconductor cooling chip and a heating wire. The cooling capacity of the semiconductor cooling chip is 100W, and the power of the heating wire is 200W.

3. The contact angle characterization device for precise temperature control coupled measurement under multi-gas atmosphere as described in claim 1, characterized in that, The main body of the experiment includes a stainless steel support (1) and a stainless steel shell (2), with the main pressure gauge (4) placed on the stainless steel shell (2).

4. The contact angle characterization device for precise temperature control coupled measurement under a multi-gas atmosphere according to any one of claims 1-3, characterized in that, The heat dissipation structure includes a heat sink (11) and a cooling fan (12). The heat sink (11) is located inside the insulation material (10), and the cooling fan (12) is located on both sides of the insulation material (10).

5. The contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere as described in claim 4, characterized in that, The heat sink (11) has aluminum heat sink fins and is connected to the Peltier element array (7) by thermally conductive grease with a thermal conductivity of 8.5 W / mK.

6. The contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere as described in claim 5, characterized in that, The precision temperature control module also includes a programmable power supply (13) and a computer (14), which are connected to the programmable power supply (13), the main data acquisition unit (9), and the heat dissipation structure.

7. The contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere as described in claim 6, characterized in that, The contact angle dynamic measurement module includes a CCD camera (15) and a dynamic data acquisition instrument (16). The CCD camera (15) has a pressure-resistant glass window on one side, and the dynamic data acquisition instrument (16) is connected to the CCD camera (15).

8. The contact angle characterization device for precise temperature control coupling measurement under multi-gas atmosphere as described in claim 7, characterized in that, The laser-induced fluorescence measurement module includes a laser (17), a lens (18), a beam shaper (19), a first reflector (20), a second reflector (21), a spectrometer (22), and a fluorescence data acquisition instrument (23). The first reflector (20) and the second reflector (21) are set to the pressure-resistant glass window. The spectrometer (22) is connected to the fluorescence data acquisition instrument (23). The laser (17) is set to the first reflector (20). The lens (18) and the beam shaper (19) are set on the laser path of the laser (17). The laser (17) generates a laser beam that can be measured and used. The laser beam is adjusted by the first reflector (20) and enters the test area. After obtaining the required information, it is reflected by the second reflector (21) into the spectrometer (22). Finally, the information is recorded by the fluorescence data acquisition instrument (23).

9. The contact angle characterization device for precise temperature control coupled measurement under multi-gas atmosphere as described in claim 1, characterized in that, The gas atmosphere control module includes an inlet pressure gauge (24), an inlet storage tank (25), an inlet pipe (26), an inlet flow meter (27), an inlet valve (28), an exhaust valve (29), an exhaust flow meter (30), an exhaust pipe (31), a gas-liquid separator (32), an inlet storage tank (25), and an inlet pressure gauge (24). Both the inlet pipe (26) and the exhaust pipe (31) are connected to the gas pipe interface (5). The inlet pipe (26) is equipped with an inlet pressure gauge (24), an inlet storage tank (25), an inlet flow meter (27), and an inlet valve (28) in sequence. The exhaust pipe (31) is equipped with an exhaust valve (29), an exhaust flow meter (30), a gas-liquid separator (32), an inlet storage tank (25), and an inlet pressure gauge (24) in sequence.

10. The method for operating the contact angle characterization device described in any one of claims 1-9 under precise temperature control coupling measurement in a multi-gas atmosphere, characterized in that, It includes the following steps: Step 1: Check the airtightness of the device, connect the various pipelines, place the heat exchange surface to be tested on the Peltier element array (7), adjust the power supply to achieve rapid heating or cooling process, and use the thermocouple (8), main data acquisition instrument (9), and heat dissipation structure in conjunction with the computer (14) to control the real-time feedback adjustment of the temperature to the required test requirements. Step 2: The contact angle dynamic measurement module is coupled with the laser-induced fluorescence measurement module to test the entire droplet contact angle change process. The droplet to be measured is fluorescently marked. The contact angle dynamic measurement module dynamically records the contact angle change, adjusts the laser power and the reflector angle to ensure that the beam passes through the test area, obtains the overall temperature field and flow information, and further couples and corrects to form a more accurate contact angle measurement result. Step 3: Adjust the gas entering the experimental body, monitor the pressure values ​​at various points in real time, control the gas discharge, and combine the gas intake and exhaust processes to adjust the pressure inside the experimental body in real time, so as to realize the contact angle test process under complex environments such as different pressures.

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