Heating structure with variable heat flux density distribution

Abstract

The invention belongs to the technical field of nuclear fusion, and particularly relates to a heating structure with variable heat flux density distribution. Comprising a base body, an insulating coating and an electric heating coating, a flow channel is arranged in the base body, a to-be-heated surface is arranged on the outer surface of the base body and coated with the insulating coating, the to-be-heated surface of the base body is covered with the insulating coating, and the insulating coating is covered with the electric heating coating. The experimental device has the beneficial effects that the experimental device is provided according to the characteristics of single-face heating, multi-face heating, high heat flux density, high temperature and the like of heating experiment demand particularity with variable heat flux density, the current situation that the current first wall material CHF test mainly takes numerical calculation and low heat flux density simulation test research is changed, and the experimental device is suitable for large-scale popularization and application. The experimental platform and the experimental method which are wide in working condition parameter, high in heat flow density and higher in universality are provided for the CHF test of the first wall material.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fusion, and in particular relates to a heating structure with variable heat flux density distribution. Background Art

[0002] Critical heat flux (CHF) is a key parameter that affects the safe operation of nuclear power equipment. Critical heat flux experiments and their mechanism research have always been a hot topic in the field of material experiments. The first wall is the core component of the fusion device. It directly faces the high-temperature plasma during operation and protects peripheral components and equipment from high temperatures of up to 5.9MW / m 2 The impact of heat flow and high-energy particle flow. Traditional CHF experimental devices all use traditional heat transfer tubes, narrow slits, and rectangular channel structures, which can only achieve body heating, not single-sided heating, and cannot meet the experimental requirements of simulating the heat generated by the first wall absorbing plasma radiation. It is necessary to design a heating structure with variable heat flux density distribution. Summary of the invention

[0003] The purpose of the present invention is to provide a heating structure with variable heat flux density distribution, which can be used to meet experimental requirements such as simulating the heat generated by the first wall absorbing plasma radiation.

[0004] The technical solution of the present invention is as follows: a heating structure with variable heat flux density, including a substrate, an insulating coating, and an electric heating coating. A flow channel is provided inside the substrate, a surface to be heated is provided on the outer surface of the substrate, and an insulating coating is coated. The insulating coating covers the surface to be heated of the substrate, and the electric heating coating covers the insulating coating.

[0005] The insulating coating is made of ceramic materials such as aluminum oxide and aluminum nitride.

[0006] The electric heating coating is made of alloy materials such as nickel-chromium alloy, nickel-chromium-aluminum alloy, iron-chromium-aluminum, etc.

[0007] The substrate is made of high temperature resistant alloy.

[0008] The cross section of the substrate is rectangular, triangular or irregular.

[0009] The number of the surfaces to be heated on the substrate is single or multiple.

[0010] The substrate is provided with bolt holes, and the electrodes are fixed on the bolt holes of the substrate through bolts and insulating gaskets, and are fully fitted with the electric heating coating.

[0011] The beneficial effects of the present invention are as follows: the present invention provides an experimental device according to the special requirements of heating experiments with variable heat flux density, including single-sided heating, multi-sided heating, high heat flux density, high temperature and the like, which changes the current situation in which the CHF test of the first wall material is mainly based on numerical calculation and low heat flux density simulation test research, and provides an experimental platform and experimental method with wide operating parameters, high heat flux density and stronger versatility for the CHF test of the first wall material. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG1 is a schematic diagram of a single-sided heating structure with variable heat flux density; FIG2 is a schematic diagram of a double-sided heating structure with variable heat flux density; FIG3 is a schematic diagram of a CHF experimental device with a single-sided heating structure having a variable heat flux density; FIG4 is a schematic diagram of the installation of a CHF experimental device with a single-sided heating structure with variable heat flux density.

[0013] In the figure: 1 substrate, 2 insulating coating, 3 electric heating coating, 4 bolt, 5 electrode. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] A heating structure with variable heat flux density comprises: a substrate 1, an insulating coating 2, an electric heating coating 3, and an electrode 5. Figure 1 and 2 As shown, a flow channel is provided inside the substrate 1 for conveying the cooling medium. The cross-sectional structure of the substrate 1 depends on the experimental requirements and can be rectangular, triangular or irregular. The substrate 1 is made of a high-temperature resistant alloy. A heating surface is provided on the outer surface of the substrate 1 and coated with an insulating coating 2. The number of heating surfaces depends on the experimental requirements and can be single or multiple. The insulating coating 2 covers the heating surface of the substrate 1. The electric heating coating 3 covers the insulating coating 2. As shown in FIG. Figure 4 As shown, the substrate 1 is provided with bolt holes, and the electrode 5 is fixed to the bolt holes of the substrate 1 through bolts 4 and insulating gaskets, and is fully fitted with the electric heating coating 3. The insulating coating 2 can be made of ceramic materials such as aluminum oxide and aluminum nitride according to requirements. The electric heating coating 3 can be made of alloy materials such as nickel-chromium alloy, nickel-chromium-aluminum alloy, iron-chromium-aluminum, etc. according to requirements.

[0016] As shown in FIG1 , this embodiment shows a single-sided heating structure with variable heat flux density, which is used to solve the experimental requirements of simulating the first wall absorbing plasma radiation to generate heat, including a substrate 1, an insulating coating 2, and an electrothermal coating 3. In this embodiment, when the current flows through the electrothermal coating 1, the heat generated is conducted to the substrate 1 through the insulating coating 2, and the external cooling medium flows through the cooling channel in the substrate 1 to take away the heat, thereby realizing the simulation of the single-sided heating experimental requirements. In this embodiment, the material of the substrate 1 is preferably INCONEL800 high temperature resistant alloy, and its structure and size are customized according to the requirements. In this embodiment, the insulating coating material is preferably alumina, and its thickness is very important for insulation and heat transfer effects. Its thickness can be controlled according to the insulation requirements, but since the thickness will affect the heat transfer effect, in this embodiment, its thickness is preferably 0.1~0.3mm, which can ensure that the insulation resistance between the electrothermal coating and the substrate of the experimental piece reaches 1MΩ (250V DC) or more. In this embodiment, the electrothermal coating material is preferably a nickel-chromium-aluminum alloy, and its thickness can be controlled according to the power density requirements. However, since the thickness will increase the internal stress of the material, excessive thickness may cause the material to peel off. In this embodiment, the thickness is preferably 0.2~0.4mm; in this embodiment, the thickness of the electrothermal coating material can be designed according to the experimental requirements, and uniform spraying can be used to carry out simulated equal heat flux density experiments. Different electrothermal layer thicknesses can also be designed in different cross-sections to meet the non-equal heat flux density experimental requirements of different cross-sections and different heat flux densities. In this embodiment, the experimental piece base material itself is also made of metal material. In order to meet the experimental requirements, a slight change is made on this experimental piece, and it can be used for traditional body heating and surface heating mixed heating experiments.

[0017] As shown in Figure 2, this embodiment shows a double-sided heating structure with variable heat flux density, which is used to solve the experimental requirement of simulating the heat generation on the two symmetrical sides of the rectangular test piece substrate. In this embodiment, the insulating coating and the electric heating coating are sprayed on the two symmetrical surfaces to be heated of the rectangular cross-section test piece substrate.

[0018] As shown in Figures 3 and 4, this embodiment shows an experimental piece that uses a single-sided heating structure with high heat flux density, and shows the installation method of the electrode. In this embodiment, the electrode is pressed against the base of the experimental piece by bolts, and is in full and good contact with the electric heating coating; between the electrode and the bolt, a high-temperature resistant insulating gasket is used to ensure that the insulation between the electrode, the electric heating coating and the base of the experimental piece is not affected. Preferably, the insulating gasket in this embodiment is in the form of a multi-layer gasket, wherein the insulating material is polyetheretherketone and the supporting material is stainless steel. In this embodiment, water is used as a cooling medium to flow through the middle of the long strip of experimental piece, and an external power supply device supplies power to the electric heating coating through the electrode. By changing the power of the external power supply, the heat flux density of the experimental piece can be adjusted so that the maximum heat flux density of the electric heating coating can reach 6MW / m 2, meeting the requirements of the first wall experimental conditions.

[0019] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment, it is not used to limit the present invention. Any technician familiar with this patent can make some changes, combinations or modifications to equivalent embodiments of equivalent changes by using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change, combination and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the solution of the present invention.

Claims

1. A heating structure with variable heat flux density, characterized in that: It includes a substrate, an insulating coating and an electric heating coating. A flow channel is arranged inside the substrate, a heating surface is arranged on the outer surface of the substrate and coated with the insulating coating. The insulating coating covers the heating surface of the substrate, and the electric heating coating covers the insulating coating.

2. A heating structure with variable heat flux density as claimed in claim 1, characterized in that: The insulating coating is made of ceramic materials such as aluminum oxide and aluminum nitride.

3. A heating structure with variable heat flux density as claimed in claim 1, characterized in that: The electric heating coating is made of alloy materials such as nickel-chromium alloy, nickel-chromium-aluminum alloy, iron-chromium-aluminum, etc.

4. A heating structure with variable heat flux density as claimed in claim 1, characterized in that: The substrate is made of high temperature resistant alloy.

5. A heating structure with variable heat flux density as claimed in claim 1, characterized in that: The cross section of the substrate is rectangular, triangular or irregular.

6. A heating structure with variable heat flux density as claimed in claim 1, characterized in that: The number of the surfaces to be heated on the substrate is single or multiple.

7. A heating structure with variable heat flux density as claimed in claim 1, characterized in that: The substrate is provided with bolt holes, and the electrodes are fixed on the bolt holes of the substrate through bolts and insulating gaskets, and are fully fitted with the electric heating coating.

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