CN113865125A

CN113865125A - Stainless steel-based solar selective absorption coating

Info

Publication number: CN113865125A
Application number: CN202111166237.3A
Authority: CN
Inventors: 宫殿清; 牛蕊; 杨鹏; 李克伟; 崔泽琴; 王晓波; 韩彦莎
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2021-12-31
Anticipated expiration: 2041-09-30
Also published as: CN113865125B

Abstract

The invention discloses a solar selective absorbing coating capable of resisting high temperature and used in an atmospheric environment. The selective absorption coating takes stainless steel as a raw material, utilizes multi-arc ion plating as a preparation means, and generates a multilayer nitrogen-oxygen stainless steel stacked coating through the reaction of plasma stainless steel, nitrogen and oxygen. The coating has good solar energy selective absorption performance (the absorptivity is more than 0.90, and the emissivity is less than 0.15), and the coating has the advantages of simple raw materials, low cost and easy popularization. Compared with the nitrided stainless steel coating reported in the laboratory, the coating can work in the atmospheric environment for a long time at 600 ℃.

Description

Stainless steel-based solar selective absorption coating

Technical Field

The invention relates to the field of solar heat utilization, and relates to a stainless steel-based solar selective absorption coating.

Background

With the continuous consumption of various non-renewable resources on earth, the problem of resource shortage is also gradually concerned. Solar energy is an important renewable energy source, and the utilization of solar energy becomes an important development direction of the energy industry. Solar collectors are devices that convert solar energy into heat energy, and are widely used in the field of solar energy utilization. The solar selective absorption coating is a material for improving the efficiency of light-heat conversion of the solar heat collector, and the solar selective absorption coating improves the emissivity of an infrared band by reducing the reflectivity of sunlight in ultraviolet to near-infrared bands, realizes the increase of solar absorptivity, reduces the reflectivity of heat loss, and finally improves the utilization rate of solar energy. Under the action of the solar selective absorption coating, the production efficiency of the solar heat collector can be obviously improved, the cost can be obviously reduced, and the popularization of a solar utilization technology is facilitated. In order to further improve the working efficiency of the solar heat collector and reduce the cost of the solar heat collector, a solar selective absorption coating which is low in cost and can resist high temperature needs to be developed.

Disclosure of Invention

The invention aims to provide a solar selective absorbing coating which is low in cost, high in efficiency and capable of being used in an atmosphere high-temperature environment.

The stainless steel-based solar selective absorbing coating uses 304 stainless steel as a target material, uses nitrogen and oxygen as reaction gases, and utilizes a multi-arc ion plating process or a radio frequency sputtering process to prepare a multi-layer stacked solar selective absorbing coating; the coating is of a 4-layer structure, and a stainless steel priming layer (SS), a nitrided stainless steel layer (SS-N), a nitric oxide stainless steel layer (SS-NO) and an oxidized stainless steel layer (SS-O) are sequentially arranged from the substrate to the surface;

the thickness of the stainless steel priming layer is 100-200 nm; the thickness of the nitrided stainless steel layer is 240-300 nm; the thickness of the nitrogen oxide stainless steel layer is 200-260 nm; the thickness of the oxidized stainless steel layer is 240-300 nm;

the coating is annealed at 600 ℃ for 2 hours after the preparation.

The coating of the invention mainly relies on enhanced Mie scattering and constructive interference to improve the optical selective absorption performance of the coating, so that the thickness of each layer is ensured to be in a required range. The prepared coating contains a large amount of amorphous and unstable equal structures, which influences the long-term service of the coating. Annealing at 600 c for 2 hours should be performed after the preparation. The coating has good solar energy selective absorption performance (the absorptivity alpha is more than 0.90, and the emissivity epsilon is less than 0.15), and the coating has the advantages of simple raw materials, low cost and easy popularization. Compared with the nitrided stainless steel coating reported in the laboratory, the coating can work in the atmospheric environment for a long time at 600 ℃.

Drawings

FIG. 1 is a schematic view of the structure of the coating of the present invention.

FIG. 2 is a cross-sectional view of a coating prepared according to the present invention.

FIG. 3 is a graph of the optical properties of the coating prepared in example 1.

FIG. 4 reflectance curves for coatings prepared in example 1 after 200 hours at 600 ℃.

Detailed Description

For a better understanding of the present invention, the present invention is further illustrated below with reference to a specific example 1. The technical solution claimed in the present invention is not limited to the following embodiments.

Example 1

The embodiment provides a stainless steel-based solar selective absorption coating, which sequentially comprises a stainless steel priming layer (SS), a nitrided stainless steel layer (SS-N), a nitric oxide stainless steel layer (SS-NO) and an oxidized stainless steel layer (SS-O) from a base body to the surface. The coating is prepared by a multi-arc ion plating process. The coating substrate is made of 316L stainless steel, and the target is made of 304 stainless steel. The deposition current was 50A and the bias was 800V. The argon flow was maintained at 80 sccm.

The process of each layer is as follows:

SS layer, deposition time 1 min.

SS-N layer, nitrogen flow 30sccm, deposition time 2 min.

And an SS-NO layer with the nitrogen flow of 30sccm, the oxygen flow of 10sccm and the deposition time of 1.5 min.

And an SS-O layer with the oxygen flow of 40sccm and the deposition time of 2 min.

Then, the annealing was performed at 600 ℃ for 2 hours in an atmospheric environment.

The optical performance of the coating is absorption rate of 0.94 and emissivity of 0.15.

FIG. 3 is a graph of the optical properties of the coatings prepared in example 1 (before annealing); FIG. 4 is a plot of the reflectance of the coating prepared in example 1 after 200 hours at 600 ℃.

The absorptivity and emissivity are calculated according to the formula of absorptivity and emissivity:

and

in the formula, α and ∈ represent the absorption rate and the emission rate, respectively. E_solRepresenting solar radiation energy, E_bRepresenting black body radiant energy, R reflectivity, all as a function of wavelength λ.

It was calculated that both the absorption and the emission decreased with increasing reflectivity. The reflectance is therefore reduced as much as possible in the short wavelength range (< 2.5 μm) and increased as much as possible in the long wavelength range (> 2.5 μm). The reflectivity in fig. 3 and 4 exhibits exactly the above-mentioned law.

As can be seen from fig. 4, the optical performance of the coating prepared by the invention after working for 200 hours at 600 ℃ is 0.91 of absorptivity and 0.13 of emissivity; the coating of the invention can meet the requirement of working at high temperature and has the advantage of high efficiency.

Claims

1. A stainless steel based solar selective absorber coating characterized by: preparing a multi-layer stacked solar selective absorption coating by using 304 stainless steel as a target material, nitrogen and oxygen as reaction gases and argon as a plasma gas and using a multi-arc ion plating process or a radio frequency sputtering process; the coating is of a 4-layer structure and sequentially comprises a stainless steel priming layer, a nitrided stainless steel layer, a nitrogen oxidized stainless steel layer and an oxidized stainless steel layer from the substrate to the surface;

the coating is annealed at 600 ℃ for 2 hours after the preparation.

2. The stainless steel based solar selective absorber coating according to claim 1, wherein: the used target material composition is 304 stainless steel with the purity of not less than 99.9 percent.

3. The stainless steel based solar selective absorber coating according to claim 1, wherein: in the preparation process, argon with the purity of not less than 99.9 percent is used as plasma gas, nitrogen with the purity of not less than 99.9 percent and oxygen with the purity of not less than 99.9 percent are used as reaction gas.

4. A stainless steel based solar selective absorber coating according to any of claims 1-3, wherein: the coating is prepared by adopting a multi-arc ion plating process; the deposition current is 50A, and the bias voltage is 800V; keeping the argon flow at 80 sccm;

the process of each layer is as follows:

a stainless steel bottom layer is formed, and the deposition time is 1 minute;

nitriding the stainless steel layer, wherein the nitrogen flow is 30sccm, and the deposition time is 2 min;

nitrogen oxide stainless steel layer with nitrogen flow of 30sccm, oxygen flow of 10sccm and deposition time of 1.5 min;

oxidizing the stainless steel layer, wherein the oxygen flow is 40sccm, and the deposition time is 2 min.

5. A stainless steel based solar selective absorber coating according to any of claims 1-3, wherein: 316L stainless steel is selected as the coating substrate.