Title:
REFRIGERATION CYCLE DEVICE
Document Type and Number:
WIPO Patent Application WO/2024/071215
Kind Code:
A1
Abstract:
This refrigeration cycle device (1) comprises: a first circuit (5a) through which a first refrigerant circulates; a second circuit (10) through which a carbon dioxide refrigerant and a refrigeration machine oil circulate; a cascade heat exchanger (35) which causes the first refrigerant and the carbon dioxide refrigerant to exchange heat; and a control unit (80). The second circuit (10) has: a container for storing the carbon dioxide refrigerant and the refrigeration machine oil; an intake pipe (23a) which connects the intake side of a second compressor (21) and the container; an oil return path (23b) for returning the refrigeration machine oil from a lower portion of the container to the intake pipe; and a valve provided to the oil return path. The control unit (80), during a defrost operation, closes the valve when the pressures or temperatures of the carbon dioxide refrigerant and the refrigeration machine oil inside the container are less than a predetermined pressure or a predetermined temperature which corresponds to a boundary temperature at which the density of the carbon dioxide refrigerant and the density of the refrigeration machine oil inside the container become the same and when the valve is in an open state.
Inventors:
IYOSHI YUTA
YAMANOI YOSHIKI
YAMANOI YOSHIKI
Application Number:
PCT/JP2023/035188
Publication Date:
April 04, 2024
Filing Date:
September 27, 2023
Export Citation:
Assignee:
DAIKIN IND LTD (JP)
International Classes:
F25B7/00; F25B1/00; F25B47/02
Attorney, Agent or Firm:
SHINJYU GLOBAL IP (JP)
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