| 摘要 |
PURPOSE:To restrict refrigerant noise generated near the first branch part and perform a silent operation by a method wherein after the second predetermined time elapses while the third opening or closing valve being in its open passage state, the first opening or closing valve is opened in its passage and a flow rate of the first flow rate control device is controlled in response to a cooling load. CONSTITUTION:In the case that an indoor device performing a heating operation is changed over in its operation to a cooling operation, a degree of opening of the first flow rate control device 9 is kept only at a predetermined degree of opening and the second opening or closing valve 22 keeps its opened passage state only for the first predetermined period of time, thereafter the second opening or closing valve 22 is closed in its passage, the first flow rate control device 9 is closed and concurrently the third opening or closing valve 23 is opened in its passage. In addition, after the opened passage state is kept for the second predetermined period of time, the first opening or closing valve 21 is opened in its passage so as to control a flow rate of the first flow rate control device 9. Under this control, a pressure at the connection parts between the first branch part 10 and the connecting pipes 6b, 6c and 6d shows a gradual variation and so refrigerant noise caused by a rapid variation of pressure is not generated. |
