To promptly restore a normal circulation when liquid refrigerant which is transferred from an outdoor unit to an indoor unit, boils to cause circulation failure of the refrigerant.
This air conditioner comprises an outdoor unit 10 for radiating and condensing refrigerant, such as R-134a, being set on a roof of a building or the like, and an indoor unit 20, which is set on every floor, for conducting cooling with refrigerant which is circulated and supplied from the outdoor unit 10. When an excess of refrigerant in the outdoor unit 10 is detected by a float sensor 12, for instance, an expansion valve 23 in the indoor unit 20 is fully opened and bubbles of refrigerant generated by the boiling in a liquid downcomer 42 are permitted to flow into a heat exchanger 22 from the expansion valve 23 together with the liquid refrigerant. The fully opened expansion valve 23 is closed based on the elapsed time and the temperature of the refrigerant supplied to the indoor unit 20. A controller 50 is provided so that large quantity of the liquid refrigerant does not flow into a gas pipe 41.
IZUMI MASASHI
IDEI NOBUHIRO
YOSHIMOTO HIROSHI
OSAKA GAS CO LTD