US 12,123,629 B2
Heat source unit and refrigeration device having low-stage and high-stage compressors with four-way switching valve
Masaaki Takegami, Osaka (JP); Naoto Kimura, Osaka (JP); and Masahiko Kaneda, Osaka (JP)
Assigned to DAIKIN INDUSTRIES, LTD., Osaka (JP)
Filed by DAIKIN INDUSTRIES, LTD., Osaka (JP)
Filed on Sep. 22, 2023, as Appl. No. 18/371,553.
Application 18/371,553 is a continuation of application No. PCT/JP2022/010813, filed on Mar. 11, 2022.
Claims priority of application No. 2021-055213 (JP), filed on Mar. 29, 2021.
Prior Publication US 2024/0011671 A1, Jan. 11, 2024
Int. Cl. F25B 1/10 (2006.01); F25B 13/00 (2006.01); F25B 41/26 (2021.01); F25B 49/02 (2006.01)
CPC F25B 1/10 (2013.01) [F25B 13/00 (2013.01); F25B 41/26 (2021.01); F25B 49/022 (2013.01); F25B 2400/075 (2013.01); F25B 2600/025 (2013.01); F25B 2600/0251 (2013.01); F25B 2600/2501 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A heat source unit connected to a utilization-side unit and configured to perform a refrigeration cycle, the heat source unit comprising:
a heat-source-side heat exchanger;
a low-stage compressor;
a high-stage compressor configured to suck and compress a refrigerant discharged from the low-stage compressor;
a four-way switching valve;
a low-stage pipe which is provided in parallel with the low-stage compressor and through which the refrigerant flows while the low-stage compressor is stopped; and
a controller, wherein
the controller is configured to activate the four-way switching valve between a first state and a second state,
wherein
in the first state, the refrigerant having evaporated in the utilization-side unit is sucked into the low-stage compressor and refrigerant discharged from the high-stage compressor is supplied to the heat-source side heat exchanger, and
in the second state, the refrigerant having evaporated in the heat source-side heat exchanger is sucked into the low-stage compressor and the refrigerant discharged from the high-stage compressor is supplied to the utilization-side unit, and wherein
the controller is further configured to:
output an instruction signal for activating the four-way switching valve to switch an operation performed by the heat source unit while the low-stage compressor is stopped and the high-stage compressor is operating, and
output the instruction signal to the four-way switching valve after stopping the low-stage compressor, if the low-stage compressor is operating at a time of switching the operation performed by the heat source unit.