Thermal switch based on negative thermal expansion

Abstract

The invention discloses a thermal switch based on negative thermal expansion. The thermal switch comprises a negative thermal expansion element and a conductive element. The negative thermal expansion element is made of a negative thermal expansion material. The negative thermal expansion element is connected with the conductive element. When the temperature of the negative thermal expansion element is above a predetermined threshold, the conductive element and a thermal load are disconnected. When the temperature of the negative thermal expansion element is below the predetermined threshold, the conductive element and the thermal load are connected. According to the invention, the thermal switch based on negative thermal expansion is simple in structure and only has two parts; the running stroke of the thermal switch is large; a large gap caused by a large stroke can reduce an angle coefficient between two end faces of the gap; radiation heat transfer can be reduced; and disconnected thermal resistance is increased.

Description

technical field [0001] The invention relates to the technical field of heat flow path control, in particular to a thermal switch based on negative thermal expansion. Background technique [0002] At present, mechanical refrigerators such as Stirling refrigerators have become the best means to provide low-temperature environments with large cooling capacity. In general, the compressor and expander of the Stirling refrigerator use linear motors to drive the vibrator respectively, and perform high-speed reciprocating linear motion at a certain frequency along the axial direction. In this way, when the refrigerator is in operation, large vibrations will be generated along the axial direction, and this vibration will be transmitted to the focal plane detector installed on the cold head of the refrigerator, thereby affecting the imaging effect of the focal plane. In order to reduce refrigeration vibration, a composite refrigeration system is proposed, which uses active and passiv...

AI Technical Summary

Problems solved by technology

[0003] Among the existing thermal switches, the structure of the thermal switch driven by the bimetal sheet is relatively complicated, and the ratio of the opening and closing thermal resistance is about 300, and the phenomenon of overcooling welding occurs during use

The memory alloy type thermal switch uses the memory alloy to provide the closing force of the thermal switch. Its structure is more complicated, and the ratio of the opening thermal resistance to the closing thermal resistance is relatively large.

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