| 摘要 |
PROBLEM TO BE SOLVED: To provide a freezing apparatus capable of detecting leakage of a refrigerant earlier and accurately irrespective changes in seasons and the amount of initial encapsulating of the refrigerant. SOLUTION: A title freezing apparatus comprises: a level sensor (refrigerant takeout pipe 22, etc.), for detecting a liquid surface level of a refrigerant stored in a liquid reservoir 3 of a refrigerant circuit, a pressure sensor 19 for detecting refrigerant pressure in the liquid reservoir 3, a temperature sensor 20 for detecting refrigerant temperature in the liquid reservoir 3; and a refrigerant leakage detection section (means) 21 for detecting leakage of the refrigerant from the refrigerant circuit by estimating refrigerant mass in the liquid reservoir when a pump down operation is performed at a predetermined time interval to recover the refrigerant in the refrigerant circuit into the liquid reservoir 3 based upon detection values with a level sensor, the pressure sensor 19, and the temperature sensor 20, and comparing the calculated amount of the refrigerant in the liquid reservoir with the refrigerant mass in the liquid reservoir calculated upon previous time pump down.
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