Vacuum degree detection device based on temperature difference power generation device

Abstract

The application discloses a vacuum degree measuring device based on a thermoelectric generator, wherein a cooling part is supported in a vacuum cavity, a thermoelectric generator is laminated on the cooling part, the thermoelectric generator comprises multiple pairs of thermoelectric arms, when the vacuum degree of a position where the thermoelectric generator is located changes, the thermoelectric generator generates detection data reflecting the vacuum degree by changing the thermal resistance, a thermal resistance block is laminated on the other end of the thermoelectric generator, a heat source part is laminated and heats the thermal resistance block, and a pressure cylinder applies pressure to the heat source part.

Description

Technical Field

[0001] This invention belongs to the field of online vacuum detection technology, and in particular, a vacuum measurement device based on a thermoelectric generator. Background Technology

[0002] Vacuum technology, as a practical and fundamental technology, has gained increasingly widespread applications due to its provision of a rarefied gas atmosphere and clean environmental conditions, which are beneficial for degassing, drying, evaporation, and arc extinguishing. Accurate measurement of gas vacuum levels is of great significance to scientific research and industrial production. In the aerospace field, vacuum measurements are required for environmental monitoring and simulation experiments of satellites, launch vehicles, and manned spacecraft, as well as for evaluating the effects of space materials and monitoring hazardous gas leaks. In the electronics industry, accurate vacuum measurements are necessary for all stages and testing processes in electronic device manufacturing, including material purification, thin film preparation, ion etching and processing, sealing, and performance testing. In the manufacturing and use of electrical equipment, vacuum level measurement also affects product quality and its service life. Furthermore, it has extensive applications in nuclear material purification, nuclear power plant safety monitoring, high-energy accelerators, and aero-engine testing and manufacturing processes.

[0003] Currently, the main vacuum measurement methods include capacitance-film gauges, thermal conductivity vacuum gauges, and ionization vacuum gauges. Capacitance-film gauges, with a measurement range of 1E5 to 1E-2 Pa, offer the advantage of high accuracy. However, their disadvantage is that the material properties and structural dimensions of the film directly affect the change in film capacitance caused by surface pressure, thus affecting the range and accuracy of the vacuum measurement. Important representatives of thermal conductivity vacuum gauges are thermocouple gauges and Pirani gauges (resistivity meters). With a measurement range of 1E5 to 1E-2 Pa, they are easy to manufacture and inexpensive. However, their measurement results are dependent on the type of gas, susceptible to contamination, and greatly affected by the environment. Ionization vacuum gauges can be divided into cold cathode ionization and hot cathode ionization, with a measurement range of 1E-1 to 1E-5 Pa. Hot cathode ionization gauges offer the advantage of accurate and stable measurement, but their disadvantage is that the filament is prone to oxidation at (absolute) pressures greater than 1E-1 Pa. Cold cathode ionization gauges have the advantage of less filament oxidation, but their disadvantages include measurement discontinuity, discharge delay effects at low pressures, and instability.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art in this country. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a vacuum degree measuring device with a wide measurement range, simple structure, easy manufacturing, and long service life.

[0006] The objective of this invention is achieved through the following technical solution: a vacuum degree measuring device based on a thermoelectric generator includes:

[0007] Vacuum cavity,

[0008] The cooling section is supported within the vacuum chamber;

[0009] A thermoelectric generator, one end of which is stacked on the cooling part, the thermoelectric generator includes multiple pairs of thermoelectric arms, the thermal resistance of the thermoelectric generator is formed by the parallel connection of the thermal resistance of the thermoelectric arms and the thermal resistance of the air filling the gap, when the vacuum level at the location of the thermoelectric generator changes, the thermal resistance of the thermoelectric generator changes to generate detection data reflecting the vacuum level.

[0010] A thermal resistance block is stacked at the other end of the thermoelectric generator;

[0011] The heat source portion is stacked and heats the thermal resistance block;

[0012] A pressure cylinder that applies pressure to the heat source portion.

[0013] In the vacuum degree measuring device based on thermoelectric generator, the vacuum degree measuring device continuously measures the air pressure in the range of 1E5Pa to 1E-2Pa.

[0014] In the vacuum degree measuring device based on thermoelectric generator, the thermoelectric generator and the thermal resistance block are arranged in series to form an integral whole.

[0015] In the vacuum degree measuring device based on thermoelectric generator, the heat source is a ceramic heating element or a flexible heating element.

[0016] In the vacuum degree measuring device based on thermoelectric generator, the material of the thermal resistance block includes nitrides, oxides, epoxy resins, or glass fibers.

[0017] In the vacuum degree measuring device based on thermoelectric generator, the thermal resistance block is provided with a first measuring point connected to the first temperature measuring device, and the bottom of the thermoelectric generator is provided with a second measuring point connected to the second temperature measuring device.

[0018] In the vacuum degree measuring device based on thermoelectric generator, the first temperature measuring device includes a thermocouple, a platinum resistance thermometer or a thermistor, and / or the second temperature measuring device includes a thermocouple, a platinum resistance thermometer or a thermistor.

[0019] In the vacuum degree measuring device based on thermoelectric generator, the heat source is connected to a DC power supply, and the thermoelectric generator is connected to a data acquisition device.

[0020] In the aforementioned vacuum degree measuring device based on thermoelectric generator, the heat source part is attached to the thermal resistance block via a copper sheet, and the thermoelectric generator is attached to the cooling part via a copper sheet.

[0021] In the vacuum degree measuring device based on thermoelectric generator, the cooling section is connected to a constant temperature water bath to form a circulating cooling system.

[0022] Compared with existing technologies, the present invention has the following advantages: Compared with other vacuum measuring devices, this device can continuously measure air pressure in the range of 1E5Pa to 1E-2Pa, and has the characteristics of a wide measurement range. The device is simple to manufacture, accurate in measurement, and has a long service life. Attached Figure Description

[0023] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0024] In the attached diagram:

[0025] Figure 1 This is a schematic diagram of a vacuum degree measuring device based on a thermoelectric generator according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of a vacuum degree measuring device based on a thermoelectric generator according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the test of vacuum degree and open circuit voltage of a vacuum degree measuring device based on a thermoelectric generator according to an embodiment of the present invention.

[0028] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0029] The following will refer to the attached diagram. Figures 1 to 3 Specific embodiments of the invention will be described in more detail below. While specific embodiments of the invention are shown in the accompanying drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0030] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0031] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0032] To better understand, such as Figures 1 to 3 As shown, the vacuum measurement device based on thermoelectric generators includes,

[0033] Vacuum cavity 6,

[0034] Cooling section 4 is supported within the vacuum chamber 6.

[0035] A thermoelectric generator 3, with one end stacked on the cooling section 4, includes multiple pairs of thermoelectric arms. The thermal resistance of the thermoelectric generator is formed by the parallel connection of the thermal resistance of the thermoelectric arms and the thermal resistance of the air filling the gaps. When the vacuum level at the location of the thermoelectric generator 3 changes, it causes a change in the thermal resistance of the thermoelectric generator 3, generating detection data reflecting the vacuum level. The change in the vacuum level at the location of the thermoelectric generator leads to a change in the thermal resistance of the air filling the gaps, causing a change in the thermal resistance of the thermoelectric generator. This change in thermal resistance alters the temperature distribution on the thermal resistance block and the thermoelectric generator, resulting in a change in the hot-end temperature of the thermoelectric generator and consequently a change in its output voltage. When the temperatures of the heat source and cooling section of the vacuum measurement device are constant, a change in vacuum level is the only factor causing a change in the overall thermal resistance of the thermoelectric generator, thus causing a change in its output voltage to generate detection data reflecting the vacuum level.

[0036] Thermal resistance block 2 is stacked at the other end of the thermoelectric generator 3.

[0037] Heat source section 1, which is stacked and heats the thermal resistance block 2,

[0038] Pressure cylinder 7 applies pressure to the heat source part 1.

[0039] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the vacuum degree measuring device continuously measures the air pressure in the range of 1E5Pa to 1E-2Pa.

[0040] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the thermoelectric generator 3 and the thermal resistance block 2 are arranged in series to form an integral whole.

[0041] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the heat source part 1 is a ceramic heating element or a flexible heating element.

[0042] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the material of the thermal resistance block 2 includes nitrides, oxides, epoxy resins, or glass fibers.

[0043] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the thermal resistance block 2 is provided with a first measuring point connected to the first temperature measuring device, and the bottom of the thermoelectric generator 3 is provided with a second measuring point connected to the second temperature measuring device.

[0044] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the first temperature measuring device includes a thermocouple, a platinum resistance thermometer, or a thermistor, and / or the second temperature measuring device includes a thermocouple, a platinum resistance thermometer, or a thermistor.

[0045] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the heat source part 1 is connected to a DC power supply, and the thermoelectric generator 3 is connected to a data acquisition device.

[0046] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the heat source part 1 is attached to the thermal resistance block 2 via a copper sheet 5, and the thermoelectric generator 3 is attached to the cooling part 4 via a copper sheet 5.

[0047] In a preferred embodiment of the vacuum degree measuring device based on the thermoelectric generator 3, the cooling section 4 is connected to the constant temperature water bath 8 to form a circulating cooling system.

[0048] The vacuum measurement device based on the thermoelectric generator 3 has a wide range of applications. It can be used for vacuum measurement in numerous scientific research and industrial fields that utilize vacuum technology, such as aerospace, electrical engineering, nuclear energy, and food processing. Specific applications include, but are not limited to, vacuum monitoring in vacuum interrupters, magnetron sputtering cavities, and SPS sintering furnace cavities. The vacuum measurement device based on the thermoelectric generator 3 arranges the thermoelectric generator 3 and a heat-generating block in series to form a whole. Constant heating and cooling control are applied at both ends to generate a defined temperature difference. The overall thermal resistance of the thermoelectric generator 3 is composed of the parallel thermal resistance of the thermoelectric arm and the air thermal resistance. When the vacuum level at the device's location changes, the air thermal resistance changes, causing a change in the overall thermal resistance of the device, resulting in a redistribution of the temperature difference across the device and the heat-generating block 2. The device's output voltage is determined by the temperature and temperature difference at the device. When the temperatures of the heat source and cooling components of the vacuum measurement device are constant, a change in vacuum level is the only factor causing a change in the overall thermal resistance of the thermoelectric generator, thus causing a change in the output voltage of the thermoelectric generator to generate detection data reflecting the vacuum level. Based on the principles of thermal resistance matching of thermal resistance blocks and the design principles of thermoelectric generators, this device can achieve continuous measurement in the range of 1e5Pa-1e-2Pa. It has the advantages of large vacuum measurement range, long life and simple manufacturing, and can effectively measure vacuum.

[0049] The vacuum degree measuring device based on the thermoelectric generator 3 has no restrictions on the shape of its various parts, and can be circular, square, rectangular, annular, or other shapes. The optimal matching method for the shape and cross-sectional dimensions of each part is to keep them consistent. The heat source part 1 of the vacuum degree measuring device can be a ceramic heating element, a flexible heating element, or other heat sources capable of heating. The material of the thermal resistance block 2 of the vacuum degree measuring device needs to have high resistance characteristics. The specific temperature resistance range needs to be selected according to the temperature at which the vacuum degree measuring device is applied. A hot-end temperature signal measurement point needs to be set at its top to provide a hot-end temperature signal and simultaneously feed back the hot-end temperature for temperature control. Temperature can be measured using various methods such as thermocouples, platinum resistance thermometers, and thermistors to provide a hot-end temperature signal and simultaneously feed back the hot-end temperature for temperature control. The optimal selection principle for its thermal resistance is the thermal resistance matching principle of the thermal resistance block, that is, the thermal resistance of the thermal resistance block 2 should be the same as the overall thermal resistance of the thermoelectric generator 3 at one atmosphere. Although other solutions may not achieve the maximum voltage change and thus reduce the vacuum degree measurement range, they are still alternative solutions of this invention. The thermal resistance block 2 can be made of materials such as nitrides, oxides, epoxy resins, and glass fibers. The thermoelectric material in the thermoelectric generator 3 of the vacuum measurement device can be selected according to the application, including Bi2Te3-based and MgAgSb-based materials in the low-temperature region, PbTe-based, GeTe-based, and cobaltite materials in the medium-temperature region, and silicon-germanium alloys and semi-Hessler materials in the high-temperature region. A cold junction temperature signal measurement point needs to be set at the bottom of the device for cold junction temperature measurement. The design principles are: as many thermoelectric arm pairs as possible to ensure that the output voltage of the thermoelectric generator is greater than 500mV at a temperature difference of 200 degrees Celsius; the duty cycle should be as low as possible, not exceeding 10%; the Seebeck coefficient of the thermoelectric material should be as high as possible, reaching 200μV / K; and the thermal resistance of the thermoelectric arm should be as high as possible, with a single thermoelectric arm having a thermal resistance of at least 400K / W. This enables continuous measurement of the full range of vacuum from 1e5Pa to 1e-2Pa using the sensor of this invention, a result that can be verified by the following embodiments. The cooling section 4 needs to provide stable cooling conditions, and various cooling methods can be selected, such as water cooling, air cooling, natural cooling, or heat transfer cooling with low-temperature objects. The specific cooling method can be selected according to the application. In order to achieve the integrity of the vacuum degree measuring device, the connection between the parts can be achieved by various methods such as adhesive bonding, mechanical connection, self-propagating high-temperature bonding, fusion welding, brazing, and diffusion welding.

[0050] In one embodiment, during the fabrication of the vacuum degree measuring device based on the thermoelectric generator 3, a circular ceramic heating element with a diameter of 24 mm is fabricated, using nickel wire as the lead wire. A zirconia ceramic with a diameter of 24 mm and a height of 32 mm is fabricated as the thermal resistance block 2.

[0051] A thermoelectric generator 3, with a diameter of 24mm, is fabricated, containing 16 pairs of thermoelectric arms, each measuring 1.4*1.4*3mm. A copper sheet 5, 24mm in diameter and 3mm thick, is also fabricated, with a 1mm diameter hole drilled in the center of its side for placing a thermocouple for temperature measurement. The vacuum measuring device is then brazed together in the following order: ceramic heating element, copper sheet 5, thermal resistance block 2, thermoelectric generator 3, and copper sheet 5, forming a single unit.

[0052] The above device is placed on the water-cooled base plate in the vacuum chamber 6. A pressure of 1 bar is applied at the top using a pressure cylinder 7 to achieve good contact between the measuring device and the water-cooled base plate. The water-cooled base plate uses an external constant temperature water bath 8 to control the cold end temperature with a temperature fluctuation of less than 0.05℃.

[0053] Temperature is controlled by a temperature controller 9, with temperature fluctuations less than 0.1℃. A DC power supply 10 powers the device, heating the hot end to 200℃. The constant temperature water bath 8 is set to 5℃. A vacuum system 11 is used to evacuate the device. Data acquisition equipment 12 records the open-circuit voltage of the thermoelectric generator 3 under conditions of 1 atmosphere, the mechanical pump vacuum limit, and the molecular pump vacuum limit. The measurement results are... Figure 3 It is evident that different voltages at different vacuum levels are sufficient to measure and distinguish the vacuum level. Furthermore, the vacuum system 11 includes a vacuum pump.

[0054] Although embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and all of these are within the scope of protection of the present invention.

Claims

1. A vacuum degree measuring device based on a thermoelectric generator, comprising, Vacuum cavity; The cooling section is supported within the vacuum chamber; A thermoelectric generator, one end of which is stacked on the cooling part, the thermoelectric generator includes multiple pairs of thermoelectric arms, the thermal resistance of the thermoelectric generator is formed by the parallel connection of the thermal resistance of the thermoelectric arms and the thermal resistance of the air filling the gaps, when the vacuum level at the location of the thermoelectric generator changes, it causes a change in the thermal resistance of the thermoelectric generator to generate detection data reflecting the vacuum level. A thermal resistance block is stacked at the other end of the thermoelectric generator; The heat source portion is stacked and heats the thermal resistance block; A pressure cylinder applies pressure to the heat source section. The thermoelectric generator and the thermal resistance block are arranged in series to form an integral unit. The vacuum degree measuring device continuously measures the air pressure in the range of 1E5Pa to 1E-2Pa. The output voltage of the thermoelectric generator is determined by the temperature and temperature difference on the thermoelectric generator. When the temperature of the heat source and cooling part of the vacuum degree measuring device is constant, the change in vacuum degree is the only factor that causes the overall thermal resistance of the thermoelectric generator to change, thereby causing the output voltage of the thermoelectric generator to change to generate detection data reflecting the vacuum degree.

2. The vacuum degree measuring device based on a thermoelectric generator according to claim 1, wherein, The heat source is a ceramic heating element or a flexible heating element.

3. The vacuum degree measuring device based on a thermoelectric generator according to claim 1, wherein, The material of the thermal resistance block includes nitrides, oxides, epoxy resins, or glass fibers.

4. The vacuum degree measuring device based on a thermoelectric generator according to claim 3, wherein, The thermal resistance block has a first measuring point connected to the first temperature measuring device, and the bottom of the thermoelectric generator has a second measuring point connected to the second temperature measuring device.

5. The vacuum degree measuring device based on a thermoelectric generator according to claim 4, wherein, The first temperature measuring device includes a thermocouple, a platinum resistance thermometer, or a thermistor, and / or the second temperature measuring device includes a thermocouple, a platinum resistance thermometer, or a thermistor.

6. The vacuum degree measuring device based on a thermoelectric generator according to claim 1, wherein, The heat source is connected to a DC power supply, and the thermoelectric generator is connected to a data acquisition device.

7. The vacuum degree measuring device based on a thermoelectric generator according to claim 1, wherein, The heat source is attached to the thermal resistance block via a copper sheet, and the thermoelectric generator is attached to the cooling part via a copper sheet.

8. The vacuum degree measuring device based on a thermoelectric generator according to claim 1, wherein, The cooling section is connected to a constant temperature water bath to form a circulating cooling system.

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