Air separation cold box for reducing surface temperature through radiation refrigeration

Abstract

The air separation cold box capable of reducing the surface temperature through radiation refrigeration comprises a box body and is characterized in that a micro-nano scale structure is constructed on the surface of the box body, the surface of the box body is coated with a special material coating, and the special material coating has high infrared emissivity; the micro-nano scale structure is formed by etching the outside of the special material coating, the micro-nano scale structure is close to the target radiation wavelength scale, and the air separation cold box for reducing the surface temperature through radiation refrigeration has the effects that radiation refrigeration is used for replacing electric energy active refrigeration, and the refrigeration energy consumption is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of air separation cold boxes, and in particular to an air separation cold box which utilizes radiation refrigeration to reduce surface temperature. Background Art

[0002] The heat energy of objects on the surface is transferred through radiation heat exchange, and the heat is discharged into the outer space with a temperature close to absolute zero through the "atmospheric window" in the form of 8-13um electromagnetic waves, achieving the purpose of self-cooling. This cooling method of releasing heat into space completely by radiation is usually called radiation cooling.

[0003] Radiative cooling is a passive cooling technology. Water vapor, carbon dioxide and ozone, three gases in the atmosphere with selective absorption and radiation characteristics, have low absorption rates in the range of 8 to 13 μm ("atmospheric window"), that is, high transmittance. Blackbody radiation at normal temperature is mainly concentrated in this band, so objects on the surface of the earth can exchange heat with outer space close to absolute zero through the "atmospheric window" through radiation, thereby obtaining a large amount of cooling.

[0004] At normal temperature, the radiation energy of objects is mainly concentrated in the 8-13μm ("atmospheric window") band. Therefore, in order to improve the effect of radiation cooling, its radiation surface needs to have a higher emissivity in the "atmospheric window" band, so as to radiate more heat into outer space.

[0005] If there is such a selective radiator, its spectral radiation characteristics are shown in the figure, the reflectivity is 1 outside the 8-13μm band, and the emissivity is 1 within the 8-13um band. Figure 1 In the figure, curves I, 2 and 3 represent the temperature T1, T2 and T3 radiation curves of the ideal radiator respectively; the solid line is the radiation spectrum distribution curve of the sky to the ground. The shaded area represents the net heat loss on the surface of the radiator, so the temperature continues to drop. Even when the temperature of the object drops to T3, the object still dissipates more heat than it gains. It can be seen that an ideal radiator with characteristics can reduce the surface temperature of the object to much lower than the ambient temperature.

[0006] If radiation cooling is used to replace the electric cooling of the air separation cold box, theoretically a large amount of cooling energy consumption can be reduced. Therefore, how to use radiation cooling in the design of the air separation cold box is a problem we need to consider. Summary of the invention

[0007] The invention discloses an air separation cold box which utilizes radiation refrigeration to reduce the surface temperature, and aims to solve the technical problem of how to utilize radiation refrigeration in the design of the air separation cold box.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] An air separation cold box that uses radiation refrigeration to reduce surface temperature, comprising a box body, characterized in that a micro-nano scale structure is constructed on the surface of the box body, the surface of the box body is coated with a special material coating, and the special material coating has a high infrared emissivity, the micro-nano scale structure is etched outside the special material coating, and the scale of the micro-nano scale structure is close to the scale of the target radiation wavelength;

[0010] The micro-nano scale structure is one or more of nanopores, nanopillars, and micropit arrays;

[0011] The micro-nano scale structure is a nanopore;

[0012] The target radiation wavelength scale is 8 to 13 um;

[0013] The special material coating is one or more of a titanium dioxide-silicon nitride composite coating, an aluminum oxide coating, a silicon carbide coating, and a zirconium oxide coating;

[0014] The special material coating is a titanium dioxide-silicon nitride composite coating.

[0015] The temperature is reduced by providing a special material coating and a micro-nano scale structure and utilizing the principle of radiation cooling, wherein the micro-nano scale structure can significantly change the optical properties of the surface, enhance the emission capability of infrared rays in a specific band, and achieve a cooling effect. The enhanced radiation cooling effect of the surface of the air separation tower processed on a microscale helps to optimize the heat exchange process in the tower. At the same time, the special material coating is a special material coating with high infrared emissivity, which has excellent emission performance in the mid- and far-infrared bands, and can efficiently transfer the heat inside the air separation tower in the form of infrared radiation, which can not only enhance radiation heat dissipation, but also has good chemical stability and mechanical properties, and is adapted to the working environment of the air separation tower. With the cooperation of the special material coating and nanopores, the temperature inside the box can be effectively reduced, and a lower and more stable temperature environment can reduce dependence on mechanical refrigeration equipment, reduce the operating time and power of mechanical refrigeration equipment, and thereby significantly reduce the electrical energy consumed by active refrigeration.

[0016] As can be seen from the above, an air separation cold box that uses radiation refrigeration to reduce the surface temperature includes a box body, characterized in that the surface of the box body is constructed with a micro-nano scale structure, the surface of the box body is coated with a special material coating, and the special material coating has a high infrared emissivity, and the micro-nano scale structure is etched outside the special material coating, and the micro-nano scale structure is close to the target radiation wavelength scale. The air separation cold box that uses radiation refrigeration to reduce the surface temperature provided by the present invention has the technical effect of using radiation refrigeration instead of electric energy active refrigeration to effectively reduce refrigeration energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the radiation spectrum distribution curve proposed by the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] The present invention discloses an air separation cold box which utilizes radiation refrigeration to reduce the surface temperature and is mainly applied to the scene where the air separation cold box is used.

[0020] Example:

[0021] The surface of the box is constructed with a micro-nano scale structure, and the surface of the box is coated with a special material coating, and the special material coating has a high infrared emissivity. The micro-nano scale structure is etched outside the special material coating, and the scale of the micro-nano scale structure is close to the scale of the target radiation wavelength;

[0022] The micro-nano scale structure is a nanopore, and the target radiation wavelength scale is 8 to 13 um, and the nanopore scale is 8 to 13 um;

[0023] The special material coating is a titanium dioxide-silicon nitride composite coating, which can enhance radiation heat dissipation and also has good chemical stability and mechanical properties, and is adapted to the working environment of the air separation tower.

[0024] Working principle: Nanopores can significantly change the optical properties of the surface and enhance the ability to emit infrared rays in a specific band. By preparing a nanopore structure with a scale close to the target radiation wavelength on the surface of the air separation tower, the surface can efficiently radiate heat in the band outside the atmospheric window, and dissipate the heat to the cosmic cold source to achieve a cooling effect. The enhanced radiation cooling effect of the micro-scale processed air separation tower surface helps to optimize the heat exchange process in the tower. Since the surface can dissipate heat more efficiently, the temperature distribution in the tower is more uniform, reducing local overheating or overcooling, and improving the efficiency of the heat exchange equipment. Under the same cooling capacity demand, the required energy input will be reduced; at the same time, the titanium dioxide-silicon nitride composite coating is a special material with high infrared emissivity. The coating has excellent emission performance in the mid- and far-infrared bands, and can efficiently transfer the heat inside the air separation tower in the form of infrared radiation. It can not only enhance radiative heat dissipation, but also has good chemical stability and mechanical properties, and can adapt to the working environment of the air separation tower. With the cooperation of micro-nano scale structures and nanopores, it can effectively reduce the temperature inside the box. The lower and more stable temperature environment can reduce dependence on mechanical refrigeration equipment, reduce the operating time and power of mechanical refrigeration equipment, and thus significantly reduce the electric energy consumed by active refrigeration. At the same time, it is beneficial to extend the service life of various equipment and materials in the air separation tower, reduce frequent maintenance and replacement due to equipment failure and aging, and reduce the energy consumed for equipment maintenance and replacement during the entire life cycle.

[0025] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An air separation cold box that uses radiation cooling to reduce the surface temperature, comprising a box body, characterized in that: The surface of the box is constructed with a micro-nano scale structure, the surface of the box is coated with a special material coating, and the special material coating has a high infrared emissivity. The micro-nano scale structure is etched outside the special material coating, and the scale of the micro-nano scale structure is close to the scale of the target radiation wavelength.

2. An air separation cold box for reducing surface temperature by using radiation cooling according to claim 1, characterized in that: The micro-nano scale structure is one or more of nanopores, nanopillars, and micropit arrays.

3. The air separation cold box for reducing the surface temperature by using radiation cooling according to claim 2, characterized in that: The micro-nano scale structure is a nanopore.

4. The air separation cold box for reducing the surface temperature by using radiation cooling according to claim 1, characterized in that: The target radiation wavelength scale is 8 to 13 um.

5. The air separation cold box for reducing the surface temperature by using radiation cooling according to claim 1, characterized in that: The special material coating is one or more of a titanium dioxide-silicon nitride composite coating, an aluminum oxide coating, a silicon carbide coating, and a zirconium oxide coating.

6. The air separation cold box for reducing the surface temperature by using radiation cooling according to claim 5, characterized in that: The special material coating is a titanium dioxide-silicon nitride composite coating.

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