Device and method for testing hemispherical emissivity of material at extremely low temperature

Abstract

The invention provides a device and a method for testing the hemispherical emissivity of a material at an extremely low temperature, which can be used for testing the hemispherical emissivity in the fields of deep space exploration and spaceflight. The device comprises a heat balance heat insulation cavity, a vacuum refrigeration system, a sample steady state control system and a data acquisition system, the heat balance heat insulation cavity comprises a cavity body, a temperature return heater and a plurality of cavity body temperature sensors, the cavity body comprises a vacuum outer cavity and a heat insulation inner cavity, and a sample is contained in the inner cavity; the vacuum refrigerating system comprises a low-temperature refrigerating part communicated with the heat insulation inner cavity and an oil-free vacuumizing part communicated with the vacuum outer cavity and the heat insulation inner cavity; the sample steady state control system comprises a sample heater and a sample temperature sensor; and the data acquisition system comprises a temperature controller connected with the cavity temperature sensor and the temperature return heater, a temperature monitor connected with the cavity temperature sensor and the sample temperature sensor, a current source meter connected with the sample heater, a voltmeter connected with the sample heater and a computer connected with the above devices.

Description

technical field [0001] The invention belongs to the field of material performance testing, and in particular relates to a device and method for testing material hemispherical emissivity at extremely low temperatures. Background technique [0002] Because the deep space millions of kilometers away from the earth is a dark and cold space, the outside temperature is generally tens of K, or even lower to several K, close to absolute zero. For aircraft in deep space environment, such as Mars probes and new technology aircraft, the working temperature of their radiators, structural materials, and surface materials is between 40K and 50K. The hemispherical emissivity is a key parameter to characterize the thermal properties of these materials. Design effectiveness. [0003] At present, when foreign aerospace departments develop new aircrafts, they usually design a huge test device and use a large amount of liquid helium to obtain an extremely low temperature environment, which cos...

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Problems solved by technology

[0003] At present, when foreign aerospace departments are developing new aircraft, they usually design a huge test device and use a large amount of liquid helium to obtain an extremely low temperature environment, which costs a lot

However, the existing emissivity testing technologies in China are all suitable for materials near room temperature, and there is still no hemispherical emissivity testing method and testing device that can meet the requirements of extremely low temperatures.

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