| 摘要 |
PROBLEM TO BE SOLVED: To perform ice-making operation by utilizing an electric power available at night and reduce power consumption during cooling operation in the daytime by effectively utilizing cold heat accumulated by the ice-making operation. SOLUTION: A series connection circuit between a variable speed compressor 2b and a second two-way valve SV2 is parallely connected to a series connection circuit among a constant speed compressor 2a, an outdoor heat exchanger 3, an outdoor expansion valve 5 and a first two-way valve SV1, and, moreover, a bypass valve BV is provided between an outlet pipe of the constant speed compressor 2a and an outlet pipe of the variable speed compressor 2b. A pipe between the outdoor expansion valve 5 and the first two-way valve SV1 is allowed to communicate to an outlet pipe of a heat storage tank STR via a third two-way valve SV3, and the outlet pipe of the heat storage tank STR is allowed to communicate to a collecting outlet pipe of an indoor unit 10 via a fourth two-way valve SV4. With this arrangement, a refrigerant discharged from the variable speed compressor 2b exchanges heat with cold water under a low condensation pressure with the aid of a heat exchanger HE in the heat storage tank during cooling operation performed by utilizing accumulated cold heat, whereby the condensation pressure can be dropped to a great extent, and the reduction of power to be consumed by the variable speed compressor 2b and the improvement of reliability thereof can be achieved. |
