| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technology of early detecting malfunction of the drive unit of an expander in a cryogenic refrigeration machine.SOLUTION: In a cryogenic refrigeration machine 100, an expander 10 generates cold by expanding refrigerant gas. A compressor 1 compresses refrigerant gas returning from the expander 10. A pipeline 7 is connected to the expander 10 and the compressor 1, and circulates refrigerant gas between the expander 10 and the compressor 1. A determiner 76 determines whether the variable period of pressure of refrigerant gas flowing in the pipeline 7 is within a predetermined range. The determiner 76 may determine whether the variable period of pressure of a low-pressure pipeline in which low-pressure refrigerant gas flows from the expander 10 toward the compressor 1 is within a predetermined range.</p> |
