| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability of detection of refrigerant leak in a freezing apparatus. SOLUTION: A generation section 21 and a reception section 22 are provided in an adjacent manner on a casing 11 of an indoor unit 10. The generation section 21 generates ultrasonic waves toward a floor, and the reception section 22 receives ultrasonic waves reflected on the floor. A leak detection section measures arrival time required front the generation section 21 to the reception section 22. Further, the leak detection section sets time the ultrasonic waves reach with no refrigerant leak from. the generation section 21 to the reception section 22, as a reference time. Once any refrigerant leak is caused, refrigerant concentration in the air is changed to change a sound velocity. Since the arrival time is hereby changed, the leak detection section judges to be refrigerant leak when a time difference between the reference time and the arrival time becomes a predetermined judgement time or more. |
