Method and system for measuring heat transfer coefficient of plate based on cubic structure
Through the combination of multi-material assembly of cube structures, embedded electric heating wire heating and infrared imaging, the accuracy and efficiency problems of multi-material composite structures in traditional heat transfer measurement are solved, and high-precision heat transfer coefficient calculation and equipment simplification are achieved.
Patent Information
- Application Number
- CN202510645719.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-19
- Publication Date
- 2025-08-08
AI Technical Summary
Traditional heat transfer measurement methods have problems such as insufficient measurement accuracy, difficulty in sample preparation, complicated data processing and limited to a single material or structure in multi-material composite structures, especially in large-size and multi-faceted structures, which are difficult to ensure measurement accuracy and efficiency.
Using a cube structure, the sheets of different materials are assembled into cubes, embedded electric heating wires are uniformly heated, combined with multi-sided temperature measurement and infrared thermal imaging, the heat transfer coefficient is calculated through a data processing algorithm, and data correction and fit is performed using a multi-channel data acquisition and processing system.
High-precision heat transfer coefficient measurement of multi-material cubes is achieved, local temperature inequality and contact deviation are overcome, measurement accuracy and efficiency are improved, equipment needs are simplified, and adaptability and scalability are strong.
Smart Images
Figure CN120446202A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of heat transfer measurement technology, and in particular to a method and system for measuring the heat transfer coefficient of a plate based on a cubic structure. Background Art
[0002] The heat transfer coefficient is an important physical parameter that describes the ability of heat to be conducted in a substance. Among traditional technologies, the steady-state hot plate method, the laser flash method, and infrared thermal imaging methods are often used to measure the heat transfer of thin films and small-scale structures. However, most existing methods are mainly aimed at single materials or only measure single-side situations, and usually require high-precision sample preparation and complex calibration processes. Data deviations are prone to occur when faced with multi-material composite structures. In addition, some methods use contact heat flow meters and temperature sensors for measurement, but in the case of large-scale, multi-faceted structures, due to the mutual influence between sensors and environmental heat loss, traditional methods are difficult to guarantee overall measurement accuracy.
[0003] For example, currently, measuring the heat transfer coefficient of large-scale materials requires placing the material between hot and cold chambers, measuring the temperature and heat flow on both sides, and then calculating the heat transfer coefficient. This requires setting up hot and cold chambers, which is cumbersome. Furthermore, when comparing materials with smaller differences in heat transfer coefficients, errors can easily be introduced due to operational or environmental variations.
[0004] Therefore, the prior art has the following problems:
[0005] Insufficient measurement accuracy: Traditional methods rely on a single data channel, and problems such as local temperature non-uniformity, poor contact, and environmental heat dissipation often lead to large errors in measurement results.
[0006] Difficulty in sample preparation: In some film and sheet measurement methods, the sample symmetry requirements and thickness matching are very strict, which makes it difficult to adapt to the actual conditions of different types of sheets.
[0007] Complex data processing: Traditional methods often require complex calibration steps. When using a single sensor, the data collection and processing process is cumbersome, making it difficult to achieve multi-point and comprehensive data coverage.
[0008] Limited to a single material or structure: Most current technologies are only aimed at measuring the heat transfer of a single structure or material, and lack effective testing methods for the heat transfer parameters of complex structures composed of multiple materials.
[0009] In recent years, the application of multi-signal fusion technology, combining infrared imaging with local temperature sensors, in heat transfer measurements has been initially validated. For example, steady-state infrared thermography, which utilizes a uniform light source for heating and an infrared lens to capture the temperature distribution, has demonstrated excellent applicability for multi-point measurements of thin film heat transfer coefficients. Furthermore, heat distribution measurements using heating wires and infrared thermography have also provided a reference for characterizing large solid samples.
[0010] While these methods have achieved some success in single-material testing, they still face significant deficiencies in measurement accuracy, repeatability, and efficiency when testing multi-material cubes with subtle structural differences. Traditional methods often overlook the data redundancy and complementary advantages offered by simultaneous multi-surface measurement, and fail to fully utilize modern infrared thermal imaging and data fitting technologies. Summary of the Invention
[0011] The present invention provides a method and system for measuring the heat transfer coefficient of a plate based on a cube structure, which is used to measure the heat transfer coefficient of a variety of plates with high precision, eliminate local temperature unevenness and contact deviation, and achieve high-precision characterization of the heat transfer coefficient of the plate.
[0012] The present invention provides a method for measuring the heat transfer coefficient of a plate having a cubic structure, comprising the following steps:
[0013] Cube construction: Assemble no more than six boards of different materials and / or surface textures into a cube, and fix the boards with heat-resistant sealing glue;
[0014] Uniform heating: Evenly distributed heating wires are set inside the cube to form a uniform and stable temperature gradient by controlling the heating power;
[0015] Multi-surface temperature measurement: Temperature probes and heat flux meters are placed on both the inside and outside of each face of the cube to record the temperature distribution and heat flux density of the cube in real time;
[0016] Infrared thermal imaging: Use an infrared thermal imager to perform non-contact temperature acquisition on the outer surface of the cube, and obtain the temperature rise data of each outer surface of the cube from the outside, so as to qualitatively obtain the heat transfer coefficient of different material plates;
[0017] Data processing: The data acquisition and processing system records data in real time, and the data processing algorithm is used to comprehensively analyze the temperature gradient and heat flux density to calculate the heat transfer coefficient.
[0018] The present invention makes different materials with small differences into plates, assembles them into a hollow cube, and heats the interior with electric heating wires to form a hot chamber, while the outside of the cube is a cold chamber. The inner and outer wall temperatures of each face of the cube and the heat flow of each face are measured over a period of approximately three to six hours, and the heat transfer coefficient of each face can be calculated. This ensures that different materials are measured in the same environment and under the same operating conditions, and the heat transfer coefficients of plates with small differences in structure can be calculated relatively accurately.
[0019] Furthermore, each of the plates has a different microstructure or surface treatment method, the thickness of each plate is between 0.5 mm and 5 mm, and the surface of the plate is pre-treated to form different roughness.
[0020] Furthermore, the heating wires are arranged in a symmetrical grid, with a heat-resistant temperature of at least 300° C., and are equipped with a temperature control circuit to achieve dynamic regulation of the heating power.
[0021] Furthermore, the temperature probes are thermocouple probes, with at least three installed inside each face of the cube and at least five installed outside. The installation positions of the temperature probes cover the surface center, edge and heat-resistant sealing colloid area of the plate.
[0022] Furthermore, in the infrared thermal imaging step, the temperature rise data of each outer surface of the cube is used to determine the temperature rise status of each face of the cube, and compared with the data collected by the temperature probe to correct the temperature distribution anomaly.
[0023] Furthermore, the data processing algorithm in the data processing step includes fitting the temperature gradient and heat flux density using the least squares method, calculating the heat transfer coefficient based on the finite element inversion algorithm, and correcting the influence of ambient thermal radiation and contact thermal resistance.
[0024] Furthermore, the cube is integrally sealed after being assembled to prevent heat leakage and environmental interference inside the cube.
[0025] Furthermore, the output power of the heating wire is adjusted in real time according to the data collected by the temperature probe, and the sampling frequency is not less than 300 Hz.
[0026] Furthermore, the heat flux meter used in multi-surface temperature measurement is a miniature heat flux sensor installed on the inner side of the plate, corresponding to the position of the temperature probe, and calibrated with a known heat flux standard to ensure the consistency and repeatability of the data at each measurement point.
[0027] The present invention also provides a measurement system for the above-mentioned measurement method, which is assembled into a cube by no more than six types of plates, and the plates are fixed with heat-resistant sealing colloid. A symmetrical grid of heating wires is provided in the cube, and a temperature probe and a heat flow meter connected to the data acquisition and processing system are respectively arranged on the inside / outside of each plate, as well as an infrared thermal imager connected to the data acquisition and processing system.
[0028] The beneficial effects of the present invention include:
[0029] 1. Multi-faceted synchronous measurement technology: By simultaneously collecting temperature and heat flow data on the six faces of the cube, the heat transfer coefficient of plates of different materials can be conveniently and quickly measured. This overcomes the local deviation problem existing in traditional single-faceted measurement methods and greatly simplifies the measurement equipment, eliminating the need for dedicated hot and cold chambers, while also saving a large amount of test site space.
[0030] 2. Combination of embedded heating and non-contact infrared measurement: The embedded electric heating wire is used to achieve uniform internal heating, and infrared thermal imaging is used to detect the temperature distribution of the entire surface to ensure the uniformity of the temperature field and data verification, thereby improving measurement accuracy and data credibility.
[0031] 3. Modular sensor system design: Through the modular temperature and heat flow sensor array, the number and distribution of sensors can be flexibly adjusted according to test requirements, improving adaptability and scalability in practical applications.
[0032] 4. Data processing and model inversion: Data processing algorithms and multi-point data are used to perform least squares fitting and numerical simulation of the temperature field, so as to more accurately infer the value of the heat transfer coefficient and avoid the error accumulation problem caused by insufficient single data. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 The flowchart of the method and system for measuring the heat transfer coefficient of a plate with a cube structure according to the present invention.
[0034] Figure 2 This is a schematic diagram of the cross-sectional structure of a cube in the measurement system of the heat transfer coefficient of a plate based on a cube structure of the present invention.
[0035] Reference numerals:
[0036] Heating wire 1, temperature probe 2, heat flow meter 3. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.
[0038] Example 1:
[0039] like Figure 1 As shown, the method for measuring the heat transfer coefficient of a plate having a cubic structure according to the present invention comprises the following steps:
[0040] Cube construction: Assemble no more than six plates of different materials and surface structures into a 40 cm square cube, and fix the plates with heat-resistant sealing colloid. The plates can be metals, polymers, ceramics, composite materials, etc., and each plate has a different microstructure or surface treatment method from each other. The purpose is to simulate the complexity of heat transfer in actual engineering. The thickness of each plate is between 0.5 mm and 5 mm, and the surface of the plate is pre-treated to form different roughness (such as chemical plating, sandblasting, etc.), so that the surface roughness and thermal radiation characteristics of each plate are slightly different, which helps to distinguish the heat transfer coefficients of different plates in actual measurements. After the cube is assembled, it is sealed as a whole to prevent heat leakage and environmental interference inside the cube, while also ensuring that no air infiltration occurs during the heating process, and that heat is fully transferred at the interface.
[0041] Uniform Heating: Heating wires are arranged in a symmetrical grid within the cube, ensuring uniform heating across all facets. This ensures comparable data across sensor areas and reduces the risk of localized overheating or uneven heat dissipation. The heating wires have a heat resistance of at least 300°C, and a temperature control circuit dynamically adjusts the heating power. By controlling the heating power of the temperature control circuit, a uniform and stable temperature gradient is created, maintaining the temperature within a predetermined range.
[0042] Multi-surface temperature measurement: To measure the heat transfer coefficient of each cube face, high-precision thermocouple probes and heat flow meters are installed on both the inside and outside of each face to record the cube's temperature distribution and heat flux density in real time. At least three thermocouple probes are installed on each face, and at least five on the outside. The temperature probes are located at the center and edge of the board surface, as well as in the heat-resistant sealant area.
[0043] The heat flux meter is a miniature heat flux sensor installed inside the plate, aligned with the temperature probe. It is calibrated with a known heat flux standard to ensure consistent and repeatable data at each measurement point. By measuring heat flux density inside and on the surface of the plate, the miniature heat flux sensor can capture local temperature variations caused by uneven conduction.
[0044] The combined measurement of temperature head and heat flux meter not only supports cross comparison of data, but also allows numerical fitting and model verification of temperature gradient changes and heat flux density distribution, thereby accurately calculating the heat transfer coefficient.
[0045] When measuring temperature, the output power of the heating wire is adjusted in real time according to the data collected by the thermocouple probe, and the sampling frequency is not less than 300 Hz.
[0046] Infrared thermal imaging: Using an infrared thermal imager, non-contact temperature measurement is performed on the cube's exterior surfaces. This data is used to obtain temperature rise data on each exterior surface, thereby qualitatively determining the heat transfer coefficients of different material panels. The temperature rise data for each cube surface is compared with data collected by temperature probes to correct for temperature distribution anomalies. Infrared thermal imaging data is used not only for global temperature field monitoring but also to identify local temperature anomalies and adjust heating control strategies. For example, infrared thermal imaging can be used to determine whether the symmetry of the temperature distribution meets design requirements and whether adjustments to the heating or sensor calibration processes are necessary.
[0047] The present invention uses embedded heating wires to achieve uniform internal heating, while simultaneously utilizing infrared thermal imaging to detect full-surface temperature distribution, thereby ensuring temperature field uniformity and data verification. This dual approach significantly improves measurement accuracy and data credibility.
[0048] Data processing: The data acquisition and processing system built according to existing technologies uses a multi-channel data recording board to support high-speed data synchronous acquisition, ensuring that the data of each temperature probe and heat flow meter is transmitted within millisecond-level time accuracy.
[0049] The data acquisition and processing system is also connected to the infrared thermal imager and transmits data to the central data processing unit via wired or wireless transmission. The data acquisition and processing system also supports data backup and automatic storage to ensure data integrity during long-term measurement experiments.
[0050] Then, the data is collected in real time through the data acquisition and processing system, and the collected data is preprocessed, including noise filtering, abnormal data removal, and time delay correction.
[0051] The heat transfer coefficient is calculated by comprehensively analyzing the temperature gradient and heat flux using a data processing algorithm. The data processing algorithm includes fitting the temperature gradient and heat flux using the least squares method, determining a numerical model of the temperature gradient and heat flux for each surface of each plate, and correcting for the effects of ambient thermal radiation and contact thermal resistance.
[0052] The heat transfer coefficient is then calculated based on a finite element inversion algorithm. This algorithm combines sensor data with infrared thermal imaging data to calculate the heat transfer coefficient of the plate through a numerical inversion method.
[0053] The algorithm incorporates a mathematical heat transfer model, using the temperature difference between each surface and the corresponding heat flux density to calculate the heat transfer coefficient of each plate under actual operating conditions. Factoring in ambient heat radiation, contact surface thermal resistance, and other factors, the algorithm is then appropriately modified to improve the accuracy of data fitting.
[0054] The final output of the heat transfer coefficient data is verified for accuracy by comparing it with the standard sample, and the measurement error range of each surface is listed in the data report.
[0055] This data processing method makes full use of multi-point and multi-angle data, reduces the impact of single data point errors, and improves overall measurement accuracy.
[0056] The present invention makes different materials with small differences into plates, assembles them into a hollow cube, and heats the interior with electric heating wires to form a hot chamber, while the outside of the cube is a cold chamber. The inner and outer wall temperatures of each face of the cube and the heat flow of each face are measured over a period of approximately three to six hours, and the heat transfer coefficient of each face can be calculated. This ensures that different materials are measured in the same environment and under the same operating conditions, and the heat transfer coefficients of plates with small differences in structure can be calculated relatively accurately.
[0057] The present invention is compared with the traditional single-side measurement method in multiple dimensions:
[0058] Table 1:
[0059]
[0060]
[0061] As can be seen from Table 1, multiple indicators illustrate that the present invention has obvious advantages in terms of measurement data accuracy, calibration reliability and environmental interference control.
[0062] After reasonable preheating calibration and repeated measurements, the present invention collected a large amount of data from the six faces of the cube. Table 2 shows the preliminary measurement results and error analysis of the heat transfer coefficient of plates with different structures under standard working conditions:
[0063] Table 2:
[0064]
[0065] The data in Table 2 are obtained by taking the average value of multiple experiments and calculating the standard deviation, which shows that there are obvious differences in the heat transfer coefficients of different plate structures, and the experimental data have high repeatability.
[0066] After data acquisition, the present invention uses the established heat conduction finite element model for numerical inversion. Data fitting uses the least squares method to solve the objective function, and sensor calibration parameters are introduced for correction. The fitting results show that the error in the heat transfer coefficient of each structural plate is less than 5%, demonstrating the high accuracy and robustness of the present invention in testing different materials.
[0067] At the same time, it can be seen from Table 2 that the present invention can effectively distinguish the subtle differences in heat transfer coefficients of different plates, and the data of each plate are obviously different and have good repeatability. The analysis results indicate that:
[0068] (1) Plate type A (metal substrate) has the highest heat transfer coefficient, which is mainly attributed to its high thermal conductivity;
[0069] (2) Type D (sandblasting pretreatment) has the lowest heat transfer coefficient due to the increase in interface thermal resistance caused by the increase in surface roughness;
[0070] (3) Different pretreatment processes and material compositions have a significant impact on the temperature field distribution. Multi-point data acquisition and infrared correction can make up for the shortcomings of a single acquisition method.
[0071] The data analysis results are consistent with the theoretical expectations of steady-state infrared thermal imaging and contact thermal sensing measurement methods in existing literature, once again verifying the feasibility and superiority of the present invention.
[0072] In summary, the main advantages of the present invention include:
[0073] (1) The data collection is comprehensive and accurate, which can effectively correct the problem of uneven temperature distribution.
[0074] (2) The combined use of contact and non-contact dual measurement methods ensures data reliability.
[0075] (3) The internal heating system is reasonably designed and can dynamically adjust the temperature gradient to adapt to various experimental conditions.
[0076] (4) Advanced data processing algorithms and high-precision heat transfer coefficient calculations provide a theoretical basis for subsequent product development.
[0077] (5) The modular design of the system structure is suitable for different material combinations and has good scalability and flexibility.
[0078] In summary, this invention not only overcomes the shortcomings of traditional methods in measuring complex plate structures, but also significantly improves data accuracy and experimental efficiency, providing a solid technical foundation for efficient and precise thermal management design. This measurement system has broad applications in areas such as building energy conservation, electronic packaging, material thermal management, and new energy systems, and will promote the further development of related technologies.
[0079] Example 2:
[0080] The present invention also provides a measurement system for the measurement method described in Example 1, such as Figure 2 As shown, six types of panels are assembled into a 40cm cube, secured with a heat-resistant sealant. Each panel is 0.5mm to 5mm thick, and the surface is pre-treated to varying degrees of roughness (e.g., chemical plating, sandblasting, etc.), resulting in subtle differences in surface roughness and thermal radiation characteristics.
[0081] A symmetrical grid of heating wires 1 is arranged within the cube, and temperature probes 2 and heat flow meters 3, connected to a data acquisition and processing system (not shown), are arranged on the inside and outside of each plate, along with an infrared thermal imager (not shown) also connected to the data acquisition and processing system. The temperature probes 2 are thermocouples, with at least three installed inside each face of the cube and at least five installed outside. The temperature probes 2 are positioned to cover the center and edges of the plate surface and the heat-resistant sealant area. The heat flow meters 3 are miniature heat flow sensors, installed on the inside of the plate, corresponding to the positions of the temperature probes 2.
[0082] The above-described embodiments merely represent specific implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection of the present application. It should be noted that those skilled in the art will be able to make relevant modifications and improvements without departing from the technical concept of the present application, and these modifications and improvements fall within the scope of protection of the present application.
Claims
1. A method for measuring the heat transfer coefficient of a plate having a cubic structure, comprising the following steps: Cube construction: Assemble no more than six boards of different materials and / or surface textures into a cube, and fix the boards with heat-resistant sealing glue; Uniform heating: Evenly distributed heating wires are set inside the cube to form a uniform and stable temperature gradient by controlling the heating power; Multi-surface temperature measurement: Temperature probes and heat flux meters are placed on both the inside and outside of each face of the cube to record the temperature distribution and heat flux density of the cube in real time; Infrared thermal imaging: Use an infrared thermal imager to perform non-contact temperature acquisition on the outer surface of the cube, and obtain the temperature rise data of each outer surface of the cube from the outside, so as to qualitatively obtain the heat transfer coefficient of different material plates; Data processing: The data acquisition and processing system records data in real time, and the data processing algorithm is used to comprehensively analyze the temperature gradient and heat flux density to calculate the heat transfer coefficient.
2. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: The plates have different microstructures or surface treatment methods. The thickness of each plate is between 0.5 mm and 5 mm, and the surface of the plate is pre-treated to form different roughness.
3. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: The heating wires are arranged in a symmetrical grid shape, with a heat-resistant temperature of at least 300° C., and are equipped with a temperature control circuit to achieve dynamic adjustment of the heating power.
4. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: The temperature probes are thermocouple probes, with at least three installed inside each face of the cube and at least five installed outside. The installation positions of the temperature probes cover the surface center, edge and heat-resistant sealing colloid area of the plate.
5. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: In the infrared thermal imaging step, the temperature rise data of each outer surface of the cube is used to determine the temperature rise status of each face of the cube, and compared with the data collected by the temperature probe to correct the temperature distribution anomaly.
6. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: The data processing algorithm in the data processing step includes fitting the temperature gradient and heat flux density using the least squares method, calculating the heat transfer coefficient based on the finite element inversion algorithm, and correcting the effects of ambient thermal radiation and contact thermal resistance.
7. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: After the cube is assembled, it is sealed as a whole to prevent heat leakage and environmental interference inside the cube.
8. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: The output power of the heating wire is adjusted in real time according to the data collected by the temperature probe, and the sampling frequency is not less than 300Hz.
9. The method for measuring the heat transfer coefficient of a plate having a cubic structure according to claim 1, wherein: The heat flux meter used in multi-surface temperature measurement is a miniature heat flux sensor installed on the inside of the plate, corresponding to the position of the temperature probe, and calibrated with a known heat flux standard to ensure consistency and repeatability of data at each measurement point.
10. A measuring system for the measuring method according to any one of claims 1 to 9, characterized in that: A cube is assembled from no more than six types of panels, each panel is fixed with a heat-resistant sealing colloid, a symmetrical grid of heating wires is provided in the cube, and temperature probes and heat flow meters connected to a data acquisition and processing system are arranged on each surface of the cube, as well as an infrared thermal imager connected to the data acquisition and processing system.