| 摘要 |
A freezer is provided with a heat source-side unit (50), user-side units (21, 22), and four-way valves (55, 56). A low-stage compressor (51a) and a high-stage compressor (51c) are serially connected through an intermediate pressure pipeline (51b). The four-way valves (55, 56) are switched between a first state and a second state. The first state is a state in which an intermediate pressure coolant discharged from the low-stage compressor (51a) into the intermediate pressure piping (51b) flows into a heat source-side heat exchanger (53). The second state is a state in which the intermediate pressure coolant flows into a user-side heat exchanger (22a). |
