An alginate hydrogel thin film heat flow sensor for a billet crystallizer

Abstract

This invention discloses an alginate hydrogel thin-film heat flow sensor for steel billet crystallizers, comprising an alginate hydrogel substrate with a U-shaped planar structure including a long side and a short side. A first thin-film thermocouple and a second thin-film thermocouple are respectively disposed on the inner surface of the alginate hydrogel substrate, and the first and second thin-film thermocouples are connected by cross-linking. This invention has a reasonable design, simple structure, and is easy to implement, fully utilizing the advantages of directional flow through microstructured gas film pores.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, specifically relating to an alginate hydrogel film heat flow sensor for steel billet crystallizers. Background Technology

[0002] Heat flux sensors are widely used in aerospace, steel metallurgy, petrochemical and other fields, and have achieved great success in areas such as gas heat flux measurement, thermal response to explosion products, and thermal measurement of molten steel crystallization processes. Novel thermocouple thin-film heat flux sensor structures based on MEMS technology have recently been widely discussed due to their advantages of small size and fast response, leading to extensive research and application.

[0003] For example, in the detection of heat flow in steel billet crystallizers, molten steel easily adheres to the surface of the thin film, and may even solidify into steel, causing wear on the thin film sensor and leading to device failure and unusability. This invention effectively solves this problem. Similar Gordon-type heat flow sensors are difficult to use directly for heat flow detection in crystallizers without encapsulation, but adding an encapsulation shell would significantly increase the response time, resulting in a slow sensor response. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an alginate hydrogel film heat flow sensor for steel billet crystallizers, which addresses the shortcomings of the prior art. This sensor solves the problem that when molten steel adheres to the surface of the film or even solidifies into steel, it wears against the film sensor, causing device failure. The encapsulation shell also slows down the response speed, making it impossible to maintain a fast response speed.

[0005] The present invention adopts the following technical solution:

[0006] A heat flow sensor for a billet crystallizer using an alginate hydrogel film includes an alginate hydrogel substrate. The alginate hydrogel substrate has a U-shaped planar structure, which includes a long side and a short side. A first thin-film thermocouple and a second thin-film thermocouple are respectively disposed on the inner surface of the alginate hydrogel substrate. The first thin-film thermocouple and the second thin-film thermocouple are connected by a cross-linking method.

[0007] Specifically, the distance between the thermal nodes of the first and second thin-film thermocouples and the boundary of the alginate hydrogel substrate is 0.2 mm ± 0.1 mm.

[0008] Specifically, the first and second thin-film thermocouples both have a thin-film linewidth of 20 μm ± 10%, and are centrally located on the long and short sides of the alginate hydrogel substrate, respectively.

[0009] Specifically, the thickness of the first and second thin-film thermocouples is the same as the thickness of the alginate hydrogel substrate.

[0010] Specifically, the first thin-film thermocouple includes a first thin-film thermocouple positive electrode and a first thin-film thermocouple negative electrode, with one end of the first thin-film thermocouple positive electrode and the first thin-film thermocouple negative electrode connected together, and the first thin-film thermocouple positive electrode at the connection point is positioned above the first thin-film thermocouple negative electrode; the second thin-film thermocouple includes a second thin-film thermocouple positive electrode and a second thin-film thermocouple negative electrode, with one end of the second thin-film thermocouple positive electrode and the second thin-film thermocouple negative electrode connected together, and the second thin-film thermocouple positive electrode at the connection point is positioned above the second thin-film thermocouple negative electrode.

[0011] Furthermore, the first and second thin-film thermocouple positive electrodes are prepared by crosslinking an alginate hydrogel substrate by soaking it in sodium alginate solvent.

[0012] Furthermore, the first and second thin-film thermocouple anodes are prepared by crosslinking polyethylene silicate with an alginate hydrogel substrate.

[0013] Specifically, the first thin-film thermocouple and the second thin-film thermocouple are respectively connected to the outside via metal leads.

[0014] Furthermore, the metal leads include a first wire, a second wire, a third wire, and a fourth wire. One end of the first wire is connected to the positive electrode of the first thin-film thermocouple, and one end of the second wire is connected to the negative electrode of the first thin-film thermocouple. One end of the third wire is connected to the positive electrode of the second thin-film thermocouple, and one end of the fourth wire is connected to the negative electrode of the second thin-film thermocouple. The other ends of the first, second, third, and fourth wires are respectively connected to a voltmeter.

[0015] Specifically, the length of the short side is 6mm ± 0.1mm, the length of the long side is 7mm ± 0.1mm, the width of the short and long sides is 1mm, the total width of the alginate hydrogel substrate is 4mm ± 0.1mm, and the thickness of the alginate hydrogel substrate is 3mm ± 0.1mm.

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

[0017] A heat flow sensor for steel billet crystallizers using alginate hydrogel thin film utilizes the ultra-wear-resistant properties of alginate hydrogel to ensure that the sensor does not fail due to wear caused by the solidified steel during heat flow testing of the steel billet. Furthermore, the design without an encapsulation shell maintains a fast response speed. The alginate hydrogel substrate has a U-shaped planar structure with different lengths for the short and long sides, ensuring stable and consistent temperatures measured by the thin film thermocouple at two points. This provides a reliable basis for calculating heat flow through the relationship between temperature difference and position, and heat transfer.

[0018] Furthermore, the distance between the thermal nodes of the first and second thin-film thermocouples and the boundary of the alginate hydrogel substrate is set at 0.2mm ± 0.1mm. This allows the temperature values ​​measured by the two nodes to be different. The difference in the substrate acts as a thermal resistance layer. Given the positional difference, the heat flux density can be calculated using a heat transfer model based on the material shape and parameters, the temperature difference, and the size of the thermal resistance layer.

[0019] Furthermore, the purpose or advantage of arranging the film linewidths, all at 20 μm ± 10%, centrally on the long and short sides of the alginate hydrogel substrate is twofold. Firstly, the smaller linewidth reduces testing errors caused by temperature uniformity. Secondly, the identical linewidths, centrally positioned on the long and short sides of the alginate hydrogel substrate, ensure consistent heat transfer patterns and facilitate heat flux calculations.

[0020] Furthermore, the thickness of the first and second thin-film thermocouples is set to be the same as the thickness of the alginate hydrogel substrate, which can ensure that the heat transfer of the first and second thin-film thermocouples and the alginate hydrogel substrate is uniform and consistent, and that heat transfer errors occur in the thickness direction of the wall surface.

[0021] Furthermore, the positive and negative ends are connected, with the positive end positioned above the negative end at the connection point. This ensures uniform contact to form a hot node, thereby stabilizing the output thermoelectric potential.

[0022] Furthermore, the alginate hydrogel substrate is cross-linked by soaking in sodium alginate solvent, and it exists inside the U-shaped planar alginate hydrogel substrate, which further ensures the wear-resistant properties.

[0023] Furthermore, the negative electrode is prepared by crosslinking polyethylene silicate with an impregnated alginate hydrogel substrate and exists inside the U-shaped planar alginate hydrogel substrate, further ensuring its wear-resistant properties.

[0024] Furthermore, the first and second thin-film thermocouples are connected to the outside via metal leads, which makes it easy to extract passive voltage signals. The metal leads can also reduce internal resistance, which is beneficial for impedance matching with external instruments.

[0025] Furthermore, the other ends of the first, second, third, and fourth wires are respectively connected to a voltmeter, which makes it easy to extract the passive voltage signal and distinguish the output signals of the first and second thin-film thermocouples.

[0026] Furthermore, the length of the short side is 6mm±0.1mm, the length of the long side is 7mm±0.1mm, the width of the short and long sides is 1mm±0.1mm, the total width of the alginate hydrogel substrate is 4mm±0.1mm, and the thickness of the alginate hydrogel substrate is 3mm. This design ensures a small overall volume while facilitating preparation and ease of use. At the same time, an excessively large volume would increase the error caused by heat transfer.

[0027] In summary, this invention utilizes alginate hydrogel to prepare a thin-film heat flow sensor, which meets the requirements of ultra-hardness and wear resistance while also being miniaturized and easy to install. It can be used for heat flow measurement in high-wear environments. The invention has a reasonable scheme, simple structure, and is easy to implement, and can give full play to the advantages of directional flow in microstructured air film pores.

[0028] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0029] Figure 1 This is a front view structural diagram of the present invention;

[0030] Figure 2 This is a cross-sectional view of the present invention;

[0031] Figure 3 This is a schematic diagram illustrating the working principle of the present invention;

[0032] Figure 4 This is a schematic diagram of the heat flow output relationship.

[0033] Wherein: 1. Alginate hydrogel substrate; 2. First thin-film thermocouple positive electrode; 3. First thin-film thermocouple negative electrode; 4. Second thin-film thermocouple positive electrode; 5. Second thin-film thermocouple negative electrode; 6. First wire; 7. Second wire; 8. Third wire; 9. Fourth wire. Detailed Implementation

[0034] 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.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] It should be understood that, when used in this specification and the appended claims, 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.

[0038] 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.

[0039] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0040] 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.

[0041] This invention provides an alginate hydrogel thin-film heat flow sensor for steel billet crystallizers. Utilizing the ultra-wear-resistant properties of alginate hydrogel, it ensures that the sensor will not fail due to wear caused by the solidified steel during steel billet heat flow testing. Furthermore, the design without a casing maintains a fast response speed. The alginate hydrogel substrate is cross-linked by soaking it in sodium alginate solvent. The negative electrode is made by cross-linking polyethylene silicate with the soaked alginate hydrogel substrate; both are present within the U-shaped planar alginate hydrogel substrate, further ensuring wear resistance. The different lengths of the short and long sides of the U-shaped planar alginate hydrogel substrate ensure the stable temperature measured by the thin-film thermocouple at two points, guaranteeing the calculation of heat flow through temperature difference and positional relationships, and heat transfer relationships.

[0042] Please see Figure 1 , Figure 2 and Figure 3 The present invention discloses an alginate hydrogel thin film heat flow sensor for a billet crystallizer, comprising an alginate hydrogel substrate 1, a first thin film thermocouple, and a second thin film thermocouple. The first and second thin film thermocouples are formed on the inner surface of the alginate hydrogel substrate 1 by cross-linking. The tails of the first and second thin film thermocouples are respectively connected to corresponding metal leads. The alginate hydrogel substrate 1 has a U-shaped planar structure, which includes a long side and a short side.

[0043] The alginate hydrogel substrate 1 has a total width of 4 mm ± 0.1 mm and a thickness of 3 mm ± 0.1 mm. The short side of the alginate hydrogel substrate 1 has a length of 6 mm ± 0.1 mm and a long side has a length of 7 mm ± 0.1 mm. The width of both the long and short sides is 1 mm.

[0044] The first thin-film thermocouple includes a first thin-film thermocouple positive electrode 2 and a first thin-film thermocouple negative electrode 3, and the second thin-film thermocouple includes a second thin-film thermocouple positive electrode 4 and a second thin-film thermocouple negative electrode 5.

[0045] The positive electrode 2 and the negative electrode 3 of the first thin-film thermocouple are connected at one end, with the positive electrode at the connection point positioned above the negative electrode; the positive electrode 4 and the negative electrode 5 of the second thin-film thermocouple are connected at one end, with the positive electrode at the connection point positioned above the negative electrode.

[0046] The first thin-film thermocouple positive electrode 2 and the second thin-film thermocouple positive electrode 4 were prepared by crosslinking an alginate hydrogel substrate by soaking it in sodium alginate solvent.

[0047] The first thin-film thermocouple negative electrode 3 and the second thin-film thermocouple negative electrode 5 are prepared by crosslinking polyethylene silicate with an alginate hydrogel substrate.

[0048] The distance between the thermal nodes of the first and second thin-film thermocouples and the boundary of the alginate hydrogel substrate 1 is 0.2 mm ± 0.1 mm.

[0049] The first and second thin-film thermocouples each have a film linewidth of 20 μm ± 10%, and are respectively arranged centered on the long and short sides of the alginate hydrogel substrate 1. The first and second thin-film thermocouples formed by crosslinking have the same thickness as the alginate hydrogel substrate 1.

[0050] The metal leads include a first wire 6, a second wire 7, a third wire 8, and a fourth wire 9. One end of the first wire 6 is connected to the positive electrode 2 of the first thin-film thermocouple, one end of the second wire 7 is connected to the negative electrode 3 of the first thin-film thermocouple, one end of the third wire 8 is connected to the positive electrode 4 of the second thin-film thermocouple, and one end of the fourth wire 9 is connected to the negative electrode 5 of the second thin-film thermocouple.

[0051] The other ends of the first wire 6, the second wire 7, the third wire 8, and the fourth wire 9 are connected to a voltmeter to read data, and the heat flow is calculated by the relationship between temperature difference and position and heat transfer relationship.

[0052] Please see Figure 3 The working principle of the alginate hydrogel film heat flow sensor for steel billet crystallizer of the present invention is as follows:

[0053] A temperature difference is generated across the thermal resistance layer, and the heat flux density can be calculated using Fourier's law of heat conduction. Heat flux value q:

[0054]

[0055] Where Q is the heat flux density, in units of W / m³. 2 ); dQ is the heat flux flowing through the isothermal surface ds, in W; The heat flow temperature gradient is perpendicular to the isothermal surface; λ is the thermal conductivity of the material, in W / m³. 2 ·K).

[0056] If two isothermal surfaces with temperatures T and T+ΔT are parallel:

[0057]

[0058] Where ΔT is the temperature difference between the two isothermal surfaces, in °C; and ΔT is the distance between the two isothermal surfaces, in meters.

[0059] From the above formula, it can be seen that if the material and geometry of the heat flow meter are determined, then the heat flow value can be calculated simply by measuring the thermoelectric potential generated by the temperature difference across the thermopile on both sides of the thermal resistance layer. According to the temperature measurement principle of the thermopile, the thermoelectric potential E:

[0060] E = SΔT

[0061] Where S is the Seebeck coefficient of the thermocouple, with units of mV / ℃;

[0062] Therefore, the relationship between heat flux density and thermopile output is as follows:

[0063] Right now

[0064] Where d is the thickness of the thermal resistance layer, in meters (m).

[0065] Please see Figure 4 By using simulation calculations, with a fixed value for the magnitude of the heat flow, the thickness and thermal conductivity of the thermal resistance layer were changed to obtain the changes in the thermocouple output, thus verifying the advantages of the present invention.

[0066] In summary, the present invention provides an alginate hydrogel film heat flow sensor for billet crystallizers. Without the need for a packaging structure, it solves the problem of device failure caused by the solidification of molten steel and wear of the film sensor during heat flow detection of billet crystallizers. At the same time, it avoids the increase in response time caused by the packaging protection of traditional sensors, thus facilitating the heat flow testing of billet crystallizers.

[0067] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A hot stream sensor using a hydrogel film of alginate salt for billets crystallizer, characterized by, The application relates to a seaweed salt hydrogel base (1) which is a U-shaped plane structure, the U-shaped plane structure comprising a long side and a short side, the inner surface of the seaweed salt hydrogel base (1) being provided with a first thin film thermocouple and a second thin film thermocouple, the first thin film thermocouple and the second thin film thermocouple being connected through cross-linking, the thin film line width of the first thin film thermocouple and the second thin film thermocouple being 20 mu m + / - 10%, the first thin film thermocouple and the second thin film thermocouple being arranged in the middle of the long side and the short side of the seaweed salt hydrogel base (1) respectively, the first thin film thermocouple anode (2) and the second thin film thermocouple anode (4) being prepared by immersing a seaweed salt hydrogel base in a sodium alginate solvent for cross-linking, and the first thin film thermocouple cathode (3) and the second thin film thermocouple cathode (5) being prepared by immersing a seaweed salt hydrogel base in a polyvinyl silicate solvent for cross-linking.

2. The alginate hydrogel thin film heat flux sensor for a billet mold according to claim 1, characterized by, The distance between the hot nodes of the first thin film thermocouple and the second thin film thermocouple and the boundary of the seaweed salt hydrogel base (1) is 0.2 mm + / - 0.1 mm.

3. The alginate hydrogel thin film heat flux sensor for billets crystallizer according to claim 1, characterized in that, The thickness of the first thin film thermocouple and the second thin film thermocouple is the same as the thickness of the seaweed salt hydrogel base (1).

4. The alginate hydrogel thin film heat flux sensor for a billet mold according to claim 1, characterized by, The first thin film thermocouple comprises the first thin film thermocouple anode (2) and the first thin film thermocouple cathode (3), one end of the first thin film thermocouple anode (2) and the first thin film thermocouple cathode (3) is connected, and the first thin film thermocouple anode (2) at the connection position is arranged above the first thin film thermocouple cathode (3); the second thin film thermocouple comprises the second thin film thermocouple anode (4) and the second thin film thermocouple cathode (5), one end of the second thin film thermocouple anode (4) and the second thin film thermocouple cathode (5) is connected, and the second thin film thermocouple anode (4) at the connection position is arranged above the second thin film thermocouple cathode (5).

5. The alginate hydrogel thin film heat flux sensor for billets crystallizer according to claim 1, characterized in that, The first thin film thermocouple and the second thin film thermocouple are connected with the outside through metal lead wires.

6. The alginate hydrogel thin film heat flux sensor for a billet mold according to claim 5, characterized by The metal lead wires comprise a first lead wire (6), a second lead wire (7), a third lead wire (8) and a fourth lead wire (9), one end of the first lead wire (6) is connected with the first thin film thermocouple anode (2), one end of the second lead wire (7) is connected with the first thin film thermocouple cathode (3), one end of the third lead wire (8) is connected with the second thin film thermocouple anode (4), one end of the fourth lead wire (9) is connected with the second thin film thermocouple cathode (5), and the other ends of the first lead wire (6), the second lead wire (7), the third lead wire (8) and the fourth lead wire (9) are connected with a voltmeter respectively.

7. The alginate hydrogel thin film heat flux sensor for a billet mold according to any one of claims 1 to 6, characterized by, The length of the short side is 6 mm + / - 0.1 mm, the length of the long side is 7 mm + / - 0.1 mm, the width of the short side and the long side is 1 mm, the total width of the seaweed salt hydrogel base (1) is 4 mm + / - 0.1 mm, and the thickness of the seaweed salt hydrogel base (1) is 3 mm + / - 0.1 mm.

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