The invention discloses a Brayton
refrigeration cycle low-temperature box. The Brayton
refrigeration cycle low-temperature box comprises a box body, a heat regenerator used for heat exchange between low-temperature
nitrogen and high-temperature
nitrogen, a
turbine compressor, an expansion
machine, an aftercooler, a cooler and a high-speed motor, wherein the heat regenerator is provided with a high-temperature inlet, a high-temperature outlet, a low-temperature inlet and a low-temperature outlet; a power shaft of the high-speed motor is connected with a shaft of the
turbine compressor and drives the
turbine compressor; the other end of the power shaft of the high-speed motor stretches into the expansion
machine and is connected with an
impeller; and an inlet of the expansion
machine faces the
impeller. According to the Brayton
refrigeration cycle low-temperature box,
nitrogen serves as a refrigeration working medium, and
pollution is avoided; and the pneumatic bearing suspension technology is adopted, friction is completely avoided, and the efficiency is higher than that of an oil
lubrication compressor. The rotating speed of the turbine compressor is adjustable, a
system is stableand reliable, the requirement for the wider temperature in the box is met, and the requirement for various refrigeration temperatures can be met through one box. According to the Brayton refrigerationcycle low-temperature box, the power shaft of the high-speed motor is driven to rotate when nitrogen expands, and therefore the power of the high-speed motor can be reduced.