A metal curved substrate thin film thermocouple sensor for a crystallizer

Abstract

The application discloses a metal curved surface substrate thin film thermocouple sensor for a crystallizer, which comprises a high-temperature alloy substrate, an alumina transition layer, an alumina insulation layer, a sensitive layer and a protective layer, wherein the alumina transition layer, the alumina insulation layer, the sensitive layer and the protective layer are sequentially prepared on the high-temperature alloy substrate, and the surface of the high-temperature alloy substrate, which is in contact with the alumina transition layer, is in a curved surface structure; and the sensor can realize temperature measurement of a curved surface structure member under superhigh temperature.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature temperature measurement technology, and relates to a thin-film thermocouple sensor with a curved metal substrate for crystallizers. Background Technology

[0002] In fields such as steel metallurgy, temperature is a crucial parameter in the production process, affecting the efficiency of crystallizers. It needs to be accurately and in real-time sensed, thus requiring a device capable of measuring the surface temperature of complex metal structures. However, existing similar measuring devices are mostly based on ceramic substrates, and the highest temperature of metal substrates rarely exceeds 1000℃. Therefore, thin-film thermocouples are an important means of temperature measurement. The working principle of a thin-film thermocouple is based on the thermoelectric effect: when two different metals form a closed circuit and are subjected to a temperature difference, a potential difference is generated. A thin-film thermocouple consists of two thin films of different metal materials. These two metal film layers are prepared on a ceramic or thin-film substrate using methods such as thermal evaporation, physical vapor deposition, or chemical vapor deposition. Their two ends are connected together to form the two endpoints of the thermocouple. When the thin-film thermocouple is heated, the electrons of the two metal materials are affected by thermal energy to varying degrees, thus generating a potential difference at the junction. By measuring this potential difference, the temperature at the location of the thin-film thermocouple can be determined. Furthermore, most high-temperature components are curved surfaces, while most thin-film thermocouples are currently based on planar designs, resulting in smaller thermoelectric output signals and poor anti-interference capabilities. For example, CN109338290A discloses a thin-film temperature sensor, which includes a transition layer, a thermal growth layer, an insulating layer, and a thermocouple layer connected in sequence on an aero-engine turbine blade. The thermocouple layer is formed by overlapping a first thermocouple and a second thermocouple head-to-head, with the overlap forming a thermal junction, i.e., the measuring end. The lead wires are made of the same material as the first and second thermocouples, and are connected to the tails of the first and second thermocouples respectively through high-temperature conductive adhesive. This design is planar and cannot be used for temperature measurement of curved structural components. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a thin-film thermocouple sensor for a metal curved substrate used in crystallizers, which can realize temperature measurement of curved structural components at ultra-high temperatures.

[0004] To achieve the above objectives, the present invention discloses a metal curved substrate thin-film thermocouple sensor for crystallizers, comprising a high-temperature alloy substrate, an alumina transition layer, an alumina insulating layer, a sensitive layer, and a protective layer, wherein the alumina transition layer, the alumina insulating layer, the sensitive layer, and the protective layer are sequentially prepared on the high-temperature alloy substrate, and the surface of the high-temperature alloy substrate in contact with the alumina transition layer has a curved structure.

[0005] Furthermore, the alumina transition layer is prepared on the high-temperature alloy substrate using atomic layer deposition.

[0006] Furthermore, the sensitive layer includes a thermoelectric positive electrode and a thermoelectric negative electrode, wherein the overlapping position of the thermoelectric positive electrode and the thermoelectric negative electrode forms a temperature measuring hot node.

[0007] Furthermore, the thermoelectric positive electrode is made of platinum-rhodium alloy; the thermoelectric negative electrode is made of indium oxide thermoelectric material.

[0008] Furthermore, the preparation process of the indium oxide thermoelectric material is as follows:

[0009] Alumina nanoparticles and indium oxide powders were mixed, ball-milled, pressed into tablets, sintered at high temperature, ground, ball-milled again, and dried to obtain indium oxide thermoelectric material.

[0010] Furthermore, the protective layer is made of aluminum oxide.

[0011] Furthermore, the thickness of the protective layer is greater than or equal to 10 μm.

[0012] This invention discloses a metal curved substrate thin-film thermocouple sensor for crystallizers, comprising a high-temperature alloy substrate, an alumina transition layer, an alumina insulating layer, a sensitive layer, and a protective layer. The alumina transition layer, alumina insulating layer, sensitive layer, and protective layer are sequentially fabricated on the high-temperature alloy substrate, and the surface of the high-temperature alloy substrate in contact with the alumina transition layer has a curved structure. The thermoelectric negative electrode is made of indium oxide thermoelectric material, which is prepared by combining alumina nanoparticles and indium oxide powder.

[0013] Furthermore, the preparation process of the indium oxide thermoelectric material is as follows:

[0014] Alumina nanoparticles and indium oxide powders were mixed, ball-milled, pressed into tablets, sintered at high temperature, ground, ball-milled again, and dried to obtain indium oxide thermoelectric material.

[0015] Furthermore, the high-temperature sintering temperature is 1400℃~1500℃.

[0016] The present invention has the following beneficial effects:

[0017] In the specific operation of the metal curved substrate thin-film thermocouple sensor for crystallizers described in this invention, an alumina transition layer, an alumina insulating layer, a sensitive layer, and a protective layer are sequentially fabricated on the high-temperature alloy substrate to form a thin-film thermocouple sensor. Furthermore, the surface of the high-temperature alloy substrate in contact with the alumina transition layer has a curved structure, enabling temperature measurement of curved structures at ultra-high temperatures and expanding the application range of thin-film thermocouples. Additionally, the multi-layer thin-film design of this invention significantly enhances the bonding force between the film layers, ensuring the reliability of temperature measurement in complex environments.

[0018] Furthermore, the alumina transition layer is prepared on the high-temperature alloy substrate using atomic layer deposition. The alumina transition layer prepared by atomic layer deposition can form chemical bonds with the high-temperature alloy substrate, enhancing the bonding force and laying the foundation for the subsequent preparation of the alumina insulating layer.

[0019] Furthermore, the thermoelectric negative electrode is made of indium oxide thermoelectric material, which is prepared by combining alumina nanoparticles and indium oxide powder. This material can increase the signal output of the thin-film thermocouple and enhance its anti-interference capability. Attached Figure Description

[0020] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a structural diagram of the present invention;

[0022] Figure 2 This is an exploded view of the present invention;

[0023] Figure 3 This is a structural diagram of the sensitive layer 4 in this invention.

[0024] Among them, 1 is a high-temperature alloy substrate, 2 is an alumina transition layer, 3 is an alumina insulating layer, 4 is a sensitive layer, 5 is a thermoelectric positive electrode, 6 is a thermoelectric negative electrode, 7 is a temperature measuring hot node, and 8 is a protective layer. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0029] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0030] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0032] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0033] As is widely known, a crystallizer is a common experimental and industrial piece of equipment. The following is a detailed introduction to crystallizers: A crystallizer is a trough-shaped container used to separate crystals from a solution. Crystallizers have wide applications in wastewater and organic solvent treatment in fields such as chemical engineering, pharmaceuticals, food processing, metallurgy, photovoltaics, papermaking, and waste treatment. Especially in continuous casting machines, the crystallizer is a key piece of equipment that receives molten steel poured from the tundish and solidifies it into a solid billet shell according to a specified cross-sectional shape. The working principle of a crystallizer is based on the physicochemical laws of solubility and the crystallization process. In a crystallizer, the solute in the solution gradually reaches saturation as the solvent evaporates or the temperature decreases, and then condenses into crystals. Temperature control, solution solubility, and crystallizer design all play crucial roles in this process. Types and structures of crystallizers: According to different uses and structures, crystallizers can be divided into several types: Classified by use: Cooling crystallizer: crystallizes the solute by lowering the temperature of the solution. Evaporation crystallizer: increases the concentration of the solution and crystallizes the solute by heating and evaporating the solvent. According to structure, crystallizers can be classified as follows: Shell-and-tube crystallizers: These have two layers of tubes, the inner layer for holding the solution and the outer layer for heating or cooling. Modular crystallizers: These are composed of multiple components with different functions to adapt to complex crystallization processes. To ensure good thermal conductivity, wear resistance, mechanical strength, and hardness, and to extend their service life, the inner wall material is mainly made of copper-based alloys, such as pure copper, copper-silver alloy, phosphorus-deoxidized copper, copper-beryllium alloy, and chromium-zirconium copper alloy. Some also have a plating layer on the copper wall surface, such as chromium or nickel, tungsten, iron, or three-layer nickel, nickel-phosphorus alloy, and chromium plating, to further improve the wear resistance and smoothness of the inner wall and reduce the resistance during casting. Currently, evaporation crystallizers are the mainstream product in the crystallizer market, widely used in landfill leachate treatment, furfural wastewater treatment, papermaking black liquor concentration, crystalline silicon wastewater evaporation, and ammonium sulfate evaporation crystallization. With continuous technological advancements and accelerated industrialization, the application of crystallizers in various fields will become more widespread, and the market prospects are promising.

[0034] Thin-film thermocouple sensors are temperature sensors manufactured using thin-film technology. Their working principle is based on the thermoelectric effect. The following is a detailed introduction to thin-film thermocouple sensors:

[0035] The working principle of a thin-film thermocouple sensor is as follows: A thin-film thermocouple sensor consists of two thin metal films of different materials. When the temperature changes at the contact point between these two metal films, a thermoelectric current is generated due to the thermoelectric effect. By measuring the magnitude of this thermoelectric current, the temperature of the object being measured can be obtained. The advantages of thin-film thermocouple sensors are: High precision: Thin-film technology can produce high-precision sensors that meet the stringent requirements for temperature measurement accuracy. High response speed: Thin-film thermocouple sensors have a fast response speed, enabling them to quickly capture temperature changes. Good anti-interference performance: Due to their special structure and manufacturing process, thin-film thermocouple sensors have excellent anti-interference performance and can operate stably in complex environments. The application range of thin-film thermocouple sensors includes: Industrial fields: Thin-film thermocouple sensors have wide applications in industrial fields such as steel metallurgy, aerospace, chemical, petroleum, and light industry. In these industries, thin-film thermocouple sensors are often used for temperature measurement in processes such as metal smelting, drying, and heat treatment. Biomedical fields: In the biomedical field, thin-film thermocouple sensors can be used to measure the temperature of body surface temperature, body cavity temperature, and the temperature of tissues and blood. This is of great significance for monitoring human tissue temperature and for medical research.

[0036] Example 1

[0037] The metal curved substrate thin-film thermocouple sensor for crystallizers of the present invention includes a high-temperature alloy substrate 1, an alumina transition layer 2, an alumina insulating layer 3, a sensitive layer 4, and a protective layer 8. The alumina transition layer 2, the alumina insulating layer 3, the sensitive layer 4, and the protective layer 8 are sequentially prepared on the high-temperature alloy substrate 1, and the surface of the high-temperature alloy substrate 1 that contacts the alumina transition layer 2 has a curved structure.

[0038] It should be noted that the present invention adopts a multi-layer thin film design, which can greatly enhance the bonding force between the film layers and ensure the reliability of temperature measurement in complex environments. In addition, the surface of the high-temperature alloy substrate 1 that contacts the alumina transition layer 2 is a curved structure, which can realize temperature measurement of curved structure components under ultra-high temperature conditions.

[0039] In one embodiment of the present invention, the alumina transition layer 2 is prepared on the high-temperature alloy substrate 1 by atomic layer deposition. The alumina transition layer 2 prepared by atomic layer deposition can form chemical bonds with the high-temperature alloy substrate 1, enhance the bonding force, and lay the foundation for the subsequent preparation of the alumina insulating layer 3.

[0040] In one embodiment of the present invention, the sensitive layer 4 includes a thermoelectric positive electrode 5 and a thermoelectric negative electrode 6, wherein the overlapping position of the thermoelectric positive electrode 5 and the thermoelectric negative electrode 6 forms a temperature measuring hot node 7. In the present invention, there are multiple temperature measuring hot nodes 7, which can realize the measurement of surface temperature distribution.

[0041] Example 2

[0042] The metal curved substrate thin-film thermocouple sensor for crystallizers of the present invention includes a high-temperature alloy substrate 1, an alumina transition layer 2, an alumina insulating layer 3, a sensitive layer 4, and a protective layer 8. The alumina transition layer 2, the alumina insulating layer 3, the sensitive layer 4, and the protective layer 8 are sequentially prepared on the high-temperature alloy substrate 1, and the surface of the high-temperature alloy substrate 1 that contacts the alumina transition layer 2 has a curved structure.

[0043] The thermoelectric positive electrode 5 is made of platinum-rhodium alloy; the thermoelectric negative electrode 6 is made of indium oxide thermoelectric material, and the preparation process of the indium oxide thermoelectric material is as follows:

[0044] Alumina nanoparticles and indium oxide powder were mixed in a ball mill, with the alumina ratio being 1% to 5%. The mixed powder was then pressed into tablets and subsequently sintered at a high temperature of 1400℃ to 1500℃ in a muffle furnace. The sintered tablets were then ground into powder using an agate mortar and pestle, and finally ball-milled and dried to obtain the prepared indium oxide thermoelectric material.

[0045] In one embodiment of the present invention, the protective layer 8 is made of aluminum oxide to protect the thermoelectric positive electrode 5 and the thermoelectric negative electrode 6 and enhance their service performance in harsh environments.

[0046] Example 3

[0047] The metal curved substrate thin-film thermocouple sensor for crystallizers of the present invention includes a high-temperature alloy substrate 1, an alumina transition layer 2, an alumina insulating layer 3, a sensitive layer 4, and a protective layer 8. The alumina transition layer 2, the alumina insulating layer 3, the sensitive layer 4, and the protective layer 8 are sequentially prepared on the high-temperature alloy substrate 1, and the surface of the high-temperature alloy substrate 1 that contacts the alumina transition layer 2 has a curved structure.

[0048] The alumina transition layer 2 is prepared on the high-temperature alloy substrate 1 by atomic layer deposition; the sensitive layer 4 includes a thermoelectric positive electrode 5 and a thermoelectric negative electrode 6, wherein the overlapping position of the thermoelectric positive electrode 5 and the thermoelectric negative electrode 6 forms a temperature measuring hot node 7; the thermoelectric positive electrode 5 is made of platinum-rhodium alloy; the thermoelectric negative electrode 6 is made of indium oxide thermoelectric material, wherein the preparation process of the indium oxide thermoelectric material is as follows: alumina nanoparticles and indium oxide powder are mixed, ball-milled, pressed into tablets, sintered at high temperature, ground and ball-milled again, and dried to obtain indium oxide thermoelectric material; the protective layer 8 is made of alumina; the thickness of the protective layer 8 is greater than or equal to 10 μm.

[0049] It should be noted that the multilayer thin film design of this invention can greatly enhance the bonding force between the film layers and ensure the reliability of temperature measurement in complex environments; the indium oxide material designed and prepared can increase the signal output of the thin film thermocouple and enhance its anti-interference ability; in addition, the ultra-high temperature thin film thermocouple developed based on the metal curved surface can realize surface temperature measurement of various complex high temperature flow channels, expanding the application range of thin film thermocouples.

[0050] Furthermore, it should be noted that in the field of steel metallurgy, temperature monitoring of the crystallizer affects crystallization efficiency. To solve the problem of in-situ undisturbed temperature measurement, thin-film thermocouple temperature measurement technology has been proposed. However, currently, most thin-film thermocouples suitable for high temperatures in the field of thin-film temperature measurement are ceramic substrates, while metal substrate temperature measurement generally does not exceed 1000℃. Moreover, they suffer from problems such as low signal output and poor anti-interference ability. This invention addresses the above problems by developing an indium oxide thermoelectric material and designing and fabricating a thin-film thermocouple based on a metal substrate, enabling temperature measurement in ultra-high temperature environments and achieving in-situ temperature measurement of ultra-high temperature metal components.

[0051] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0052] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0053] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A thin-film thermocouple sensor with a curved metal substrate for use in crystallizers, characterized in that, The material includes a high-temperature alloy substrate (1), an alumina transition layer (2), an alumina insulating layer (3), a sensitive layer (4), and a protective layer (8). The alumina transition layer (2), the alumina insulating layer (3), the sensitive layer (4), and the protective layer (8) are sequentially prepared on the high-temperature alloy substrate (1). The surface of the high-temperature alloy substrate (1) that contacts the alumina transition layer (2) is a curved surface structure. The alumina transition layer (2) is prepared on the high-temperature alloy substrate (1) by atomic layer deposition. The sensitive layer (4) includes a thermoelectric positive electrode (5) and a thermoelectric negative electrode (6), wherein the overlapping position of the thermoelectric positive electrode (5) and the thermoelectric negative electrode (6) forms a temperature measuring hot node (7). The thermoelectric positive electrode (5) is made of platinum-rhodium alloy; the thermoelectric negative electrode (6) is made of indium oxide thermoelectric material; The protective layer (8) is made of aluminum oxide; The thickness of the protective layer (8) is greater than or equal to 10 μm.

2. The metal curved substrate thin-film thermocouple sensor for crystallizers according to claim 1, characterized in that, The preparation process of the indium oxide thermoelectric material is as follows: alumina nanoparticles and indium oxide powder are mixed and ball-milled, then pressed into sheets, then sintered at high temperature, then ground and ball-milled again, and finally dried to obtain the indium oxide thermoelectric material.

3. A thin-film thermocouple sensor with a curved metal substrate for use in crystallizers, characterized in that, The material includes a high-temperature alloy substrate (1), an alumina transition layer (2), an alumina insulating layer (3), a sensitive layer (4), and a protective layer (8). The alumina transition layer (2), the alumina insulating layer (3), the sensitive layer (4), and the protective layer (8) are sequentially prepared on the high-temperature alloy substrate (1). The surface of the high-temperature alloy substrate (1) that contacts the alumina transition layer (2) is a curved surface. The thermoelectric negative electrode (6) is made of indium oxide thermoelectric material, which is prepared by mixing alumina nanoparticles and indium oxide powder. The preparation process of the indium oxide thermoelectric material is as follows: after mixing alumina nanopowder and indium oxide powder, the mixture is ball-milled, then pressed into tablets, then sintered at high temperature, then ground and ball-milled again, and finally dried to obtain the indium oxide thermoelectric material. The high-temperature sintering temperature is 1400℃~1500℃.

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