| 摘要 |
PURPOSE:To allow indoor units to individually, selectively perform either cooling or heating operation at the same time by a method wherein control is carried out so that the interface between gas refrigerant and liquid refrigerant is kept lower than the preset position and the refrigerant at the outlet of a first heat exchanger is maintained at a set supercooling degree. CONSTITUTION:The valve lift of a third flow control valve 15 is increased so that the interface between the gas refrigerant and the liquid refrigerant in a gas-liquid separator 12 is maintained below the position of a liquid drain pipe 41. Thereby, lack of the heating capacity, which results from a shortage of the gas refrigerant with a decrease in the dryness of the refrigerant flowing into an relay apparatus E, is avoided. In addition, the valve lift of the third flow control valve 15 is decreased so that the refrigerant of the inlet side of a second flow control valve 13 is kept at the set suppercooling degree. As a result, the dryness of the refrigerant flowing into the relay apparatus increases, so that the flow rate of the gas refrigerant is prevented from becoming too high, and the uniform distribution of the refrigerant, which flows from the second manifold 11 into indoor units B, C and D to be brought in cooling operation, is prevented from being disturbed by lack of the supercooling of the refrigerant. |
