| 摘要 |
<p>Cold energy of a cold head of a Sterling refrigerating machine is transmitted to a cooling space in a heat insulation housing by a low temperature-side circulation circuit. Hot energy of a warm head of the Sterling refrigerating machine is discharged to the outside of a cooling chamber by a high-temperature-side first circulation circuit. A portion of the hot energy is transmitted to a condensation prevention section of a cooling chamber wall via a high-temperature-side second circulation circuit. In the high-temperature-side second circulation circuit are provided a circulation pump for circulating a secondary refrigerant sealed in the circuit and a heat exchanger exposed to the outside. At the time of defrosting of the low-temperature-side circulation circuit, a control section stops operation of the Sterling refrigerating machine while continuing operation of the circulation pump.</p> |
