| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of failure such as gas leakage.SOLUTION: A refrigeration circuit is configured so that a branch pipe A is placed between a four-way valve 10 and a water-refrigerant heat exchanger 15, a branch pipe B is placed between the water-refrigerant heat exchanger 15 and an outdoor heat exchanger 11, a two-way valve C31 is provided between this branch pipe B and the indoor heat exchanger 11, an expansion valve B30 is provided between the indoor heat exchanger 11 and the branch pipe B, an expansion valve A29 is provided between the water-refrigerant heat exchanger 15 and the branch pipe B, and a water heat exchange sensor 40 is provided between the water-refrigerant heat exchanger 15 and the expansion valve A. The refrigeration circuit includes control units 14 and 20 that exert a control for an indoor unit to perform a heating operation in a case of the heating operation using solely the indoor unit by switching the four-way valve 10 to a heating side, slightly opening the expansion valve A, setting the expansion valve B to have an opening degree according to a heating capacity, and opening the two-way valve C. Furthermore, during the heating operation solely by the indoor unit, the control units 14 and 20 control a circulation pump 18 to be actuated if the water heat exchange sensor 40 detects that a detected temperature T is equal to or higher than a first predetermined temperature, and controls the circulation pump 18 to be stopped if the water heat exchange sensor 40 detects that the detected temperature T is lower than a second predetermined temperature lower than the first predetermined temperature. |
