Material Heating Power Measurement System and Method under Solar Radiation

Abstract

This application proposes a system and method for measuring the heating power of materials under solar radiation. The system includes a housing with a perforated opening at the top. A platform is positioned near the opening inside the housing for holding the material to be measured. A light-transmitting film covers the perforated opening at the top of the housing, creating a sealed space. A cooler is located on the side wall of the housing to regulate the internal temperature. A temperature detector and the cooler are connected to a communication interface via cables. Data exchange between the communication interface and a controller is achieved via wired or wireless means. The heating power is the electrical power consumed per unit area of ​​the material by the cooler while maintaining a uniform temperature inside and outside the housing. This measurement method represents the power of the material in actual system use, making it more practical and valuable.

Description

Technical Field

[0001] This application belongs to the field of optoelectronic measurement technology, specifically relating to a measurement system and method for measuring the heating power of materials under solar radiation. Background Technology

[0002] Passive thermal regulation has garnered increasing attention in recent years due to its zero-energy capability, and holds promise for mitigating the current crisis of fossil fuels and global warming. Thermal regulation, including heating in cold weather and cooling in hot environments, is crucial for improving human thermal comfort and even for human survival in extremely cold or hot environments. On the one hand, many remote regions have harsh environments, such as the Antarctic and Arctic, the Tibetan Plateau, high-latitude regions, deserts, and tropical rainforests. In these sparsely populated areas, there is a lack of electricity and fossil resources. Human activities, including exploration and scientific research, often require long-term residence in these areas, necessitating reliable heating. On the other hand, heating plays a vital role in seawater desalination and salt extraction, but it also consumes significant amounts of energy. Therefore, the development of energy-free passive cooling and heating for thermal regulation has attracted widespread attention from academia and industry. However, there is still no definitive scheme or instrument for measuring the heating power of different materials.

[0003] Currently, various materials, such as metalloids and biomimetic multilayer structures (BMS), can generate temperature rises under sunlight. For photothermal materials, performance evaluation is primarily characterized by optical absorptivity, lacking characterization methods at the energy conversion level. While temperature rise is one way to express material performance, the rise varies under different solar irradiance and climatic conditions, hindering cross-sectional comparisons of photothermal material performance. Heating power, on the other hand, more objectively reflects the material's temperature rise performance, facilitating cross-sectional comparisons and standardized measurements. Furthermore, many photothermal materials, while absorbing solar radiation in the mid-infrared band, also exhibit infrared radiation in the mid-infrared band, demonstrating a synergistic effect of solar radiation heating and infrared radiation cooling. Therefore, quantitatively characterizing the temperature rise performance and infrared heat dissipation performance under solar radiation separately has significant scientific research value and engineering implications.

[0004] Therefore, it is necessary to design a measurement system for radiative heating power to measure the performance indicators of material heating. Summary of the Invention

[0005] To address the issues of measuring the heating power of heated materials under solar radiation, and the limited adaptability of existing measurement systems that cannot meet the requirements for measuring various materials, this application proposes a measurement system and method for measuring the heating power of materials under solar radiation.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A material heating power measurement system under solar radiation includes: a device box, a controller, a cooler, a temperature detector, a platform, a communication interface, and a light-transmitting film;

[0008] The top of the device box has a hollow opening, and a loading platform is set near the hollow opening at the top of the device box. The loading platform is used to place the heating material to be measured.

[0009] A light-transmitting film is placed over the perforated opening at the top of the device box to create a sealed space inside the device box.

[0010] The device is equipped with several temperature detectors, at least one of which is located outside the device box to detect the ambient temperature; and at least one is located inside the device box to detect the temperature of the enclosed space inside the box.

[0011] The cooler is located on the side wall of the device box and is used to regulate the temperature inside the device box;

[0012] Temperature detectors and coolers are connected to a communication interface via cables, and the communication interface exchanges data with the controller via wired or wireless means.

[0013] Currently, advanced heating materials exhibit excellent performance in absorbing and storing internal heat. They can absorb most ultraviolet radiation and capture the broad visible-near-infrared solar spectrum, effectively utilizing solar radiation energy. After absorbing thermal radiation, the material raises its own temperature and the temperature of the sealed space within the device. This temperature difference between the material and the environment is detected by a temperature detector (such as a thermocouple) and transmitted to a controller. The controller then cools the sealed measurement environment using a cooler, adjusting the cooler's power to maintain a consistent temperature within the sealed measurement space. The average power consumed by the cooler at this point is the material's heating power. The cooler typically uses a thermoelectric cooler (TEC), which utilizes the Peltier effect of semiconductor materials. The Peltier effect refers to the phenomenon where, when a direct current passes through a thermocouple composed of two semiconductor materials, one end absorbs heat while the other releases heat.

[0014] The relationship between heating power is as follows:

[0015] P heat (T)=P sun +P atm (T amb )-P rad (T)

[0016] Among them, P heat The heating power, i.e., the value to be measured, is P. sun For solar radiation, P atm Where T represents atmospheric thermal radiation, and T represents the material and measurement space temperature.amb P represents the ambient temperature. rad The emissivity of the material is low in the infrared band and can be ignored.

[0017] Under the condition that the cooler is controlled to operate and the temperature inside and outside the device box is consistent, that is, thermal equilibrium is achieved:

[0018] P heat (T)=P TEC

[0019] P can then be derived from electrical power. TEC Thus, the heating power of the material is obtained.

[0020] The electrical power consumed by the cooler can be obtained from the voltage and current values ​​when the TEC is operating:

[0021] P TEC =UI.

[0022] The method of using the material heating power measurement system under solar radiation is as follows: The material to be tested is placed and fixed on a platform. Under the influence of solar radiation, a temperature rise occurs. Through thermal conduction, the heat is diffused into the sealed space inside the device box. The temperature change is detected by a temperature detector, and the returned data is sent to the controller via a data interface. The controller then activates the cooler to maintain the temperature inside the device box at the same level as the ambient temperature. The controller records the power consumed by the cooler. The power consumed per unit area of ​​the material under test by the cooler while maintaining a uniform temperature inside and outside the device box is the material's heating power. The heating power measured in this way represents the power of the material in actual system use, making it more practical and valuable.

[0023] Beneficial effects:

[0024] The heating power measured using the method proposed in this application represents the power of the material when used in a real system, making it more practical and valuable, and offering high measurement accuracy. It can meet the needs of various material measurement problems. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the material heating power measurement system under solar radiation in Embodiment 1 of this application;

[0026] Figure 2 This is a schematic diagram of the platform on which the material to be measured for heating is placed;

[0027] Figure 3 This is a schematic diagram of the material heating power measurement system under solar radiation used for measuring material cooling power in Embodiment 2 of this application.

[0028] Wherein: 1 is the device box, 2 is the controller, 3 is the cooler, 4 is the temperature detector, 5 is the carrying platform, 6 is the communication interface, 7 is the material to be measured and heated, 8 is the light-transmitting film, and 9 is the ceramic heater. Detailed Implementation

[0029] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.

[0030] This application proposes a system and method for measuring the heating power of materials under solar radiation. The system includes a housing with a perforated opening at the top. A platform is positioned near the opening inside the housing for holding the material to be measured. A light-transmitting film covers the perforated opening at the top of the housing, creating a sealed space. A cooler is located on the side wall of the housing to regulate the internal temperature. A temperature detector and the cooler are connected to a communication interface via cables. Data exchange between the communication interface and a controller is achieved via wired or wireless means. The heating power is the electrical power consumed per unit area of ​​the material by the cooler while maintaining a uniform temperature inside and outside the housing. This measurement method represents the power of the material in actual system use, making it more practical and valuable.

[0031] Example 1

[0032] A material heating power measurement system under solar radiation, as shown in the attached document. Figure 1 As shown, it includes: device box 1, controller 2, cooler 3, temperature detector 4, loading platform 5, communication interface 6, and light-transmitting film 8;

[0033] The top of the device box is provided with a hollow opening, and a loading platform 5 is provided near the hollow opening at the top of the device box. The loading platform is used to place the heating material 7 to be measured.

[0034] A light-transmitting film 8 is placed over the perforated opening at the top of the device box to create a sealed space inside the device box.

[0035] The temperature detectors are configured to be several, at least one of which is located outside the device box to detect the ambient temperature, and at least one is located inside the device box to detect the temperature of the sealed space formed inside the box.

[0036] The cooler is located on the side wall of the device box and is used to regulate the temperature inside the device box;

[0037] Temperature detectors and coolers are connected to a communication interface via cables, and the communication interface exchanges data with the controller via wired or wireless means.

[0038] The device box is sealed with a light-transmitting film to form a closed measurement environment. The light-transmitting film also reduces heat exchange between the device box and the outside environment. The controller receives data from the temperature detector and generates control signals to act on the cooler, so that the inside of the device box is kept at a constant temperature. The cooler receives current signals for control and is used to regulate the temperature inside the device box. The communication interface is used to connect with the controller.

[0039] The method for measuring the heating power of materials under solar radiation is as follows: The material to be tested is placed and fixed on a platform. Under the action of solar radiation, a temperature rise occurs. The heat of the material is diffused into the sealed measurement environment through thermal conduction. The temperature change is detected by a temperature detector and the data is transmitted to the controller, which then starts the cooler to work and adjusts the temperature inside the device box to be consistent with the ambient temperature. The controller records the power consumed by the cooler. The power consumed by the cooler per unit area of ​​the material under tested under the condition of maintaining the same temperature inside and outside the device box is the heating power of the material.

[0040] The device box serves as insulation, isolating the internal sealed space from the external environment to create a temperature difference. Polystyrene can be a suitable material.

[0041] Installing heat sinks on the back of the platform can further improve heat transfer efficiency.

[0042] To avoid uneven internal temperature distribution, a total of seven temperature detectors are preferably provided, one of which is located outside the device housing to detect the ambient temperature; for example Figure 2 As shown, two sensors are located on the back of the platform 5 to monitor the temperature of the platform; the remaining four are located on the four side walls inside the device box to detect the temperature of the sealed space inside the device box. Using the average temperature values ​​collected by the temperature detectors inside the device box as the temperature of the sealed space inside the device box can effectively reduce random errors in temperature measurement, shorten the time required for the temperature field inside the sealed space to become constant, and thus improve measurement efficiency.

[0043] When measuring the heating power of the material 7 to be heated, it is fixed on the platform 5 with no obstruction at the top, allowing solar radiation to directly act on the material through the transparent film, causing the material to heat up. To avoid uneven internal temperature distribution, six temperature detectors 4 are used to measure at different locations, and the average value is processed in the controller 2. After control, the measured internal temperature is consistent with the ambient temperature. The controller 2 records and calculates the average electrical power P when the cooler is working. TEC Let S be the surface area of ​​the material to be heated, then P is the radiative heating power of the material to be heated.heat (T) is:

[0044]

[0045] For example, under solar radiation, a sample measuring 0.1*0.1m will heat up. To maintain a uniform temperature inside and outside the device, the cooler consumes 0.83W of power. The calculation is as follows:

[0046] A further optimization solution is to install wind deflectors around the device box to reduce the disturbance of the device box temperature caused by air convection.

[0047] A further optimization is to attach a layer of aluminum film to the outer four sides of the device box to reflect sunlight and minimize the absorption of solar radiation by the device box itself.

[0048] A further optimization is to suspend the material heating power measurement system under solar radiation in the air, for example, by using a heat-insulated bracket or a heat-insulated traction rope, so that it does not have direct contact with the ground or external facilities, thereby further reducing the heat conduction effect of surrounding objects on the device box.

[0049] The transparent film material is selected from one of ZnSe, HfO2, CaF2, and polyethylene. This type of transparent film has the characteristic of high transmittance from the solar band to the mid-infrared band, and has high transmittance for both visible and infrared bands. It can also eliminate the influence of top air heat convection on the material under test.

[0050] Example 2

[0051] The material heating power measurement system under solar radiation, based on Example 1, is shown in the attached figure. Figure 3 As shown, a ceramic heater 9 is installed inside the device box, and the ceramic heater is connected to the communication interface via a cable.

[0052] When the material under test is a radiation cooling material, the material under test will cause a temperature drop by radiating thermal energy into deep space, so that the temperature of the device box is lower than the ambient temperature of the device box. The controller controls the ceramic heater to compensate for the temperature inside the device box.

[0053] Under the condition of maintaining a uniform temperature inside and outside the device box, the electrical power consumed by the ceramic heater per unit area of ​​the radiative cooling material under test is the radiative cooling power of the radiative cooling material under test. The controller selects either a cooler or a ceramic heater based on the collected temperature difference data inside and outside the device box, thus completing the switching between radiative heating power and radiative cooling power measurement modes.

[0054] Example 3

[0055] Based on Example 1, the material heating power measurement system under solar radiation includes a filter film on the outer surface of the transparent film 8. This filter film blocks mid-infrared light while allowing solar light to pass through. Thus, the filter film allows solar energy to pass through while shielding heat loss caused by the radiative cooling of the photothermal material itself. For some materials that simultaneously experience solar radiation heating and infrared radiation cooling, Example 1 measures the combined heating power under the simultaneous effects of solar irradiation and infrared radiation cooling. The filter film can eliminate infrared radiation cooling, allowing measurement of the net heating power of the material under a single solar irradiation mode, further improving the accuracy of the material heating power measurement under solar radiation.

[0056] The filter film is preferably a transparent conductive film, and further materials include ITO conductive glass or Low-E glass.

[0057] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A material heating power measurement system under solar radiation, comprising: The device comprises a housing, controller, cooler, temperature detector, platform, communication interface, and light-transmitting film; characterized in that: The top of the device box has a hollow opening, and a loading platform is set near the hollow opening at the top of the device box. The loading platform is used to place the heating material to be tested. A light-transmitting film is placed over the perforated opening at the top of the device box to create a sealed space inside the device box. The light-transmitting film is made of one of ZnSe, HfO2, CaF2, or polyethylene. This film exhibits high transmittance from the solar band to the mid-infrared band, providing high transmittance for both visible and infrared light, and also eliminates the influence of top air convection on the material under test. Seven temperature detectors are provided: one located outside the device housing to detect ambient temperature; two located on the back of the platform to monitor its temperature; and the remaining four located on the four side walls inside the device housing to detect the temperature of the enclosed space within. A cooler is installed on the side wall of the device housing to regulate the internal temperature. The temperature detector and the cooler are connected to the communication interface via cables. The communication interface exchanges data with the controller via wired or wireless means to measure the heating power of the material to be heated by recording the power consumed by the cooler while maintaining a consistent temperature inside and outside the device box.

2. The material heating power measurement system under solar radiation according to claim 1, characterized in that: A windbreak is provided around the device box.

3. The material heating power measurement system under solar radiation according to claim 1, characterized in that: The outer four sides of the device box are covered with a layer of aluminum film to reflect sunlight.

4. The material heating power measurement system under solar radiation according to claim 1, characterized in that: The material heating power measurement system under solar radiation is supported by a heat-insulated bracket or suspended in the air by a heat-insulated traction rope.

5. The material heating power measurement system under solar radiation according to any one of claims 1 to 4, characterized in that: The average electrical power of the cooler under the condition of maintaining a uniform temperature inside and outside the device box is denoted as: Let S be the surface area of ​​the material to be heated. Then the radiative heating power of the material to be heated is... for: .

6. The material heating power measurement system under solar radiation according to any one of claims 1 to 4, characterized in that: The device box also contains a ceramic heater, which is connected to a communication interface via a cable.

7. The material heating power measurement system under solar radiation according to any one of claims 1 to 4, characterized in that: A filter film is disposed on the outer surface of the light-transmitting film, and the filter film blocks light in the mid-infrared band but allows light in the solar band to pass through.

8. A method for measuring the material heating power under solar radiation using the material heating power measurement system as described in any one of claims 1 to 4, the method comprising: Place the material to be tested for heating on the platform. Under the influence of solar radiation, a temperature rise occurs, and the heat is dissipated into the sealed space inside the device box through thermal conduction. The temperature sensor detects the temperature change and sends the temperature information to the controller via a data interface. The controller receives and responds to the information to control the cooler to operate, adjusting the internal temperature of the device box to match the external ambient temperature. During this period, the controller records the power consumption of the cooler. By maintaining a consistent temperature inside and outside the device box, the power consumed by the cooler per unit area of ​​the material to be heated is obtained as the heating power of the material.

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