LOW TEMPERATURE REFRIGERATING DEVICE HAVING SMALL REFRIGERATING CAPACITY CHANGE

摘要

A cryogenic refrigerating device that can minimize the range in which the refrigerating capability changes relative to a wide range of change in outside temperature and perform a stable refrigerating operation. This cryogenic refrigerating device comprises a compressor unit (101) provided outside a room and having a compressor (11) and a first air-cooled heat exchanger (12), an intermediate unit (103) provided inside the room and having a second air-cooled heat exchanger (31) for cooling gas from the compressor (11) through heat exchange with inside air and a cryogenic expansion machine (5). A fan (33) is additionally provided on the second air-cooled heat exchanger (31) of the intermediate unit (103), and a controller (6) is provided that has an intermediate unit air volume control portion (6a) for controlling the air volume of the fan (33) toward an increase side under a condition where the temperature of gas supplied to the cryogenic expansion machine (5) is, due to temperature rise, higher than that where the refrigerating capacity starts to decrease, while controlling the air volume of the fan (33) toward a decrease side under a condition where the temperature of gas supplied to the cryogenic expansion machine (5) is, due to temperature rise, lower than that where the refrigerating capacity starts to decrease.