A highly sensitive wind speed sensor and test equipment

Abstract

The present invention relates to a highly sensitive wind speed sensor and test equipment, including an air duct, a thin-film thermoelectric device, a temperature control hot plate, a boost noise reduction module and a data acquisition module. An installation hole for installing the thin-film thermoelectric device is provided on the air duct. The thin-film thermoelectric device is in surface contact connection with the temperature control hot plate. The thin-film thermoelectric device, the boost noise reduction module and the data acquisition module are connected in sequence. The side of the thin-film thermoelectric device in contact with the airflow to be measured in the air duct is the cold end, and the side in contact with the temperature control hot plate is the hot end. The included angle between the plane where the thin-film thermoelectric device is located and the airflow to be measured in the air duct is 0-90 degrees. Compared with the prior art, the present invention has the advantages of high sensitivity and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and more particularly to a highly sensitive wind speed sensor and test equipment. Background Art

[0002] Wind is a phenomenon caused by air flow, including wind direction and wind speed. The measurement of wind speed has extensive applications in the meteorological field. Currently, wind speed meters on the market basically use the calorimetric principle or mechanical conical cups to measure wind speed. Calorimetric wind speed meters require the gas to be dry and have a very low content of solid particles to avoid measurement errors. Mechanical cup anemometers are large in size, low in integration, and low in sensitivity, and are generally applicable to research measurements in the meteorological field. At the same time, wind speed is also an important influencing factor for convective heat transfer. Therefore, a new wind speed measurement system is proposed by measuring the heat change caused by air flow and corresponding it to the measurement of wind speed.

[0003] Thermoelectric devices are a type of heat-sensitive element that can directly convert thermal energy into electrical energy through the Seebeck effect of thermoelectric materials, and have extensive applications in the fields of aerospace, transportation, medical devices, industrial facilities, electronic devices, sensing instruments, the automotive industry, computers, etc. Therefore, thermoelectric devices can convert the magnitude of the more easily measured output electrical signal into a temperature difference signal, thereby achieving precise monitoring and measurement of temperature. However, currently commercially available thermoelectric devices usually have relatively weak thermal sensitivity because the thickness of commercially available thermoelectric devices is usually more than 2 mm, and the formula for the thermal response time is 4l 2 / π 2 D, where l represents the thickness of the thermoelectric arm and D represents the thermal diffusivity. Therefore, it is impossible to accurately distinguish the heat change brought about by low-speed air flow. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned existing technologies and provide a highly sensitive wind speed sensor and test equipment with high sensitivity.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A highly sensitive wind speed sensor includes an air duct, a thin-film thermoelectric device, a temperature control hot plate, a boost noise reduction module, and a data acquisition module. An installation hole for installing the thin-film thermoelectric device is provided on the air duct. The thin-film thermoelectric device is in surface contact connection with the temperature control hot plate. The thin-film thermoelectric device, the boost noise reduction module, and the data acquisition module are connected in sequence. The side of the thin-film thermoelectric device in contact with the airflow to be measured in the air duct is the cold end, and the side in contact with the temperature control hot plate is the hot end. The included angle between the plane where the thin-film thermoelectric device is located and the airflow to be measured in the air duct is 0 - 90 degrees.

[0007] Further, the operating temperature of the temperature control hot plate is equal to or higher than the ambient temperature.

[0008] Further, the thin film thermoelectric device adopts a π-type structure with the heat flow perpendicular to the interface.

[0009] Further, the thin film thermoelectric device is in contact with the temperature control hot plate through a thermal conductive interface material.

[0010] Further, the thermal conductive interface material is thermal conductive silicone grease, thermal conductive silicone sheet, thermal conductive phase change material or thermal conductive tape.

[0011] Further, the thin film thermoelectric device, the temperature control hot plate, the boost noise reduction module and the data acquisition module are integrally encapsulated through a packaging layer.

[0012] Further, the thin film thermoelectric device includes a base and a P-N thermoelectric pair array arranged on the base. The P-N thermoelectric pair includes an N-type thermoelectric column and a P-type thermoelectric column, and adjacent N-type thermoelectric columns and P-type thermoelectric columns are commonly connected to an electrode.

[0013] Further, at least 3 pairs of P-N thermoelectric pairs are provided.

[0014] Further, the thermoelectric material used in the thin film thermoelectric device is one or more of Bi2Te3, Sb2Te3, MgAgSb, PbTe, PbSe, SnTe, SnSe, Cu2Se, Si-Ge alloy.

[0015] The present invention also provides a wind speed test device, including the high-sensitivity wind speed sensor as described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention opens an installation hole for the thin film thermoelectric device on the air duct. The air flow to be measured in the air duct contacts the cold end of the thin film thermoelectric device, and the hot end of the thin film thermoelectric device contacts the high-precision temperature control hot plate. The convective heat transfer degree caused by different air velocities can be distinguished through the thermoelectric signal, so as to achieve the purpose of wind speed sensing and can monitor the wind speed change process in real time.

[0018] 2. The present invention can conveniently adjust the included angle between the plane where the thin film thermoelectric device is located and the air flow to be measured in the air duct according to needs, and has a large precision adjustment range.

[0019] 3. The thin film thermoelectric device in the present invention includes a P-N thermoelectric pair array. Through the arrangement of large arrays in series of P-N thermoelectric pairs, and the boost noise reduction module processes the voltage signal, the detection of tiny temperature differences can be achieved.

[0020] 4. The thin-film thermoelectric device of the present invention adopts a π-shaped P-N thermoelectric pair structure with heat flow perpendicular to the interface, which can fully collect the thermal signals received on the plane.

[0021] 5. The thin-film thermoelectric device prepared by the MEMS technology of the present invention miniaturizes and low-dimensionizes traditional thermoelectric devices, which can not only solve the problems of interface thermal resistance and resistance, but also improve the integration density and power density of P-N thermoelectric pairs, increase the signal sensitivity of differential thermal measurement, and reduce the thermal response time, so as to realize the sensitive perception of micro wind speed.

[0022] 6. The present invention can select the encapsulation scheme according to the specific use environment. Without encapsulation, the sensitivity can be maximally improved. If it is in an abnormal environment of temperature, humidity, or acidity and alkalinity, encapsulation treatment can be carried out to improve the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the present invention;

[0024] Figure 2 is a cross-sectional π-shaped structure diagram of the thin-film thermoelectric device;

[0025] Figure 3 is the voltage output change of the same wind speed at different hot-end temperatures through the present invention.

[0026] Figure 4 is the corresponding relationship between wind speed and voltage output at different hot-end temperatures through the present invention.

[0027] In the figure, 1 - air duct; 2 - pipe adapter; 3 - air flow; 4 - thin-film thermoelectric device; 5 - thermal conductive interface material; 6 - temperature control hot plate; 7 - boost and noise reduction module; 8 - data acquisition module; 9 - wire; 401 - electrode; 402 - N-type thermoelectric column; 403 - P-type thermoelectric column; 404 - substrate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0029] Embodiment 1

[0030] As Figure 1As shown in the figure, this embodiment provides a highly sensitive wind speed sensor, which includes an air duct 1, a thin-film thermoelectric device 4, a temperature control hot plate 6, a boost noise reduction module 7, and a data acquisition module 8. An installation hole for installing the thin-film thermoelectric device 4 is provided on the air duct 1. The thin-film thermoelectric device 4 is in surface contact connection with the temperature control hot plate 6. The thin-film thermoelectric device 4, the boost noise reduction module 7, and the data acquisition module 8 are connected in sequence. The side of the thin-film thermoelectric device 4 in contact with the airflow to be measured in the air duct 1 is the cold end, and the side in contact with the temperature control hot plate 6 is the hot end. The included angle between the plane where the thin-film thermoelectric device 4 is located and the airflow 3 to be measured in the air duct 1 is 0-90 degrees to meet different requirements.

[0031] The temperature control hot plate 6 has high precision, and its working temperature is equal to or higher than the ambient temperature. After the cold end receives air flow, the convective heat transfer intensifies, resulting in a temperature decrease. The temperature of the hot end is controlled by the temperature control hot plate 6, thereby generating a small temperature difference (i.e., cold at the top and hot at the bottom). The thin-film thermoelectric device 4, the boost noise reduction module 7, and the data acquisition module 8 are connected in sequence through a wire 9.

[0032] When the wind speed sensor is in use, the enhanced convective heat transfer caused by the airflow 3 to be measured makes a small temperature difference form between the cold and hot ends of the thin-film thermoelectric device 4. It is converted into a voltage signal through the thermoelectric effect of the thin-film thermoelectric device 4, and the output voltage and other signals of the thin-film thermoelectric device 4 are boosted, amplified, and noise-reduced through the boost noise reduction module 7. The data acquisition module 8 collects and records the processed electrical signals, so that the tiny wind speed can be sensitively distinguished through the thermoelectric difference signal, achieving the purpose of wind speed sensing.

[0033] In this embodiment, micro-scale thin-film thermoelectric devices are prepared using MEMS technology. Miniaturizing and low-dimensionalizing traditional thermoelectric devices can not only solve the problems of interfacial thermal resistance and resistance, but also improve the integration density and power density of P-N thermoelectric pairs, increase the signal sensitivity of differential thermal measurement, and reduce the thermal response time, thereby realizing the sensitive perception of tiny wind speed.

[0034] In this embodiment, micro-scale thin-film thermoelectric devices are prepared using micro-scale thick MEMS technology. The thin-film thermoelectric device adopts a π-shaped structure perpendicular to the interface, miniaturizing and low-dimensionalizing traditional thermoelectric devices. It can not only solve the problems of interfacial thermal resistance and resistance, obtain stable, reliable, and efficient devices, but also improve the integration density and power density of the thermoelectric module, thereby increasing the signal sensitivity of differential thermal measurement. The processing process of the thin-film thermoelectric device can include steps such as photolithography, spin coating, etching, magnetron sputtering, molecular beam epitaxy, and thermal evaporation.

[0035] In this embodiment, the structure of the thin-film thermoelectric device refers to Figure 2As shown in the figure, it includes a base 404 and a P-N thermoelectric array disposed on the base 404. The P-N thermoelectric pair includes an N-type thermoelectric column 402 and a P-type thermoelectric column 403. Adjacent N-type thermoelectric column 402 and P-type thermoelectric column 403 are commonly connected to an electrode 401. The P-N thermoelectric array in this thin-film thermoelectric device is a large logarithm array, and each P-N thermoelectric pair is connected in series in sequence, so that the sensitivity to temperature difference is extremely high, and the detection of tiny temperature difference can be realized. In a specific embodiment, there are at least 3 pairs of P-N thermoelectric pairs.

[0036] In a specific embodiment, the substrate of the thin-film thermoelectric device is one or more of silicon oxide wafer, quartz wafer, glass wafer, polyvinyl alcohol film, polyimide film, and polyester film. The thermoelectric materials used in the thin-film thermoelectric device are one or more of Bi2Te3, Sb2Te3, MgAgSb, PbTe, PbSe, SnTe, SnSe, Cu2Se, and Si-Ge alloy. The electrodes of the thin-film thermoelectric device are one or more of titanium, copper, aluminum, silver, gold, nickel, and chromium thin films.

[0037] In another embodiment, the above-mentioned high-sensitivity wind speed sensor can integrate and package the thin-film thermoelectric device, the temperature control hot plate, the boost noise reduction module, and the data acquisition module through a packaging layer according to the specific use environment to improve the service life.

[0038] Embodiment 2

[0039] In the high-sensitivity wind speed sensor provided in this embodiment, the thin-film thermoelectric device 4 is in contact with the temperature control flat plate 6 through a thermal conductive interface material 5 to reduce the contact thermal resistance between the hot end of the thin-film thermoelectric device and the temperature control flat plate 6. The thermal conductive interface material can be thermal conductive silicone grease, thermal conductive silicone sheet, thermal conductive phase change material, or thermal conductive tape, etc. The rest is the same as Embodiment 1.

[0040] Embodiment 3

[0041] This embodiment provides a wind speed test device, including the high-sensitivity wind speed sensor described in any one of Embodiments 1-2, and the influence of tiny airflow at different hot end temperatures can be tested through this test device.

[0042] As Figure 3 shown, for an airflow with a fixed speed, a thin-film thermoelectric device containing 572 pairs of P-N thermoelectric pairs is used for testing, and it can be seen that there are significant differences in voltage output at different hot end temperatures. When the airflow speed and the hot end temperature are changed simultaneously, it can be seen that there is a good corresponding relationship between the airflow speed and the voltage, and it is applicable at different hot end temperatures. It can be seen the sensitivity and stability of this test device, see Figure 4 .

[0043] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall fall within the protection scope determined by the claims.

Claims

1. A highly sensitive wind speed sensor, characterized in that, It includes an air duct (1), a thin-film thermoelectric device (4), a temperature-controlled hot plate (6), a boost and noise reduction module (7) and a data acquisition module (8). An installation hole for installing the thin-film thermoelectric device (4) is provided on the air duct (1). The thin-film thermoelectric device (4) is in surface contact connection with the temperature-controlled hot plate (6). The thin-film thermoelectric device (4), the boost and noise reduction module (7) and the data acquisition module (8) are connected in sequence. The side of the thin-film thermoelectric device (4) in contact with the airflow to be measured in the air duct (1) is the cold end, and the side in contact with the temperature-controlled hot plate (6) is the hot end. The included angle between the plane where the thin-film thermoelectric device (4) is located and the airflow to be measured (3) in the air duct (1) is 0-90 degrees; The thin-film thermoelectric device (4) adopts a π-type structure with heat flow perpendicular to the interface; The thin-film thermoelectric device (4) includes a base (404) and a P-N thermoelectric array arranged on the base (404). The P-N thermoelectric pair includes an N-type thermoelectric column (402) and a P-type thermoelectric column (403). Adjacent N-type thermoelectric columns (402) and P-type thermoelectric columns (403) are commonly connected to an electrode (401).

2. The highly sensitive wind speed sensor according to claim 1, characterized in that, The operating temperature of the temperature-controlled hot plate (6) is equal to or higher than the ambient temperature.

3. The highly sensitive wind speed sensor according to claim 1, characterized in that, The thin-film thermoelectric device (4) is in contact with the temperature-controlled hot plate (6) through a thermal conductive interface material (5).

4. The highly sensitive wind speed sensor according to claim 3, characterized in that, The thermal conductive interface material (5) is thermal conductive silicone grease, thermal conductive silicone sheet, thermal conductive phase change material or thermal conductive tape.

5. The highly sensitive wind speed sensor according to claim 1, characterized in that, The thin-film thermoelectric device (4), the temperature-controlled hot plate (6), the boost and noise reduction module (7) and the data acquisition module (8) are integrally encapsulated through a packaging layer.

6. The highly sensitive wind speed sensor according to claim 1, characterized in that There are at least 3 pairs of the P-N thermoelectric pairs.

7. The highly sensitive wind speed sensor according to claim 1, characterized in that, The thermoelectric material used in the thin-film thermoelectric device is one or more of Bi2Te3, Sb2Te3, MgAgSb, PbTe, PbSe, SnTe, SnSe, Cu2Se, Si-Ge alloy.

8. An air velocity test device, characterized in that, It includes a highly sensitive wind speed sensor as described in any one of claims 1-7.

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