Refrigeration cycle system, and method of operating the same

摘要

An HPW refrigeration cycle system, using a second coolant and a second lubricating oil, is formed adopting extention pipes (15,16) and/or a indoor unit (14) employed in a former refrigeration cycle system using a first coolant and a first lubricating oil. A lubricating oil storage apparatus (5A) is provided in the new refrigeration cycle system. While refrigerating cycle operation is being performed, the first lubricating oil still remaining in the extention pipes (15,16) and/or the indoor unit (14) is consecutively stored into the lubricating oil storage apparatus (5A) in a portion of coolant. The first coolant may be a chlorofluorocarbon-based or hydrochlorofluorocarbon-based coolant, and the first lubricating oil may be mineral oil or alkylbenzene oil. The second coolant is preferably a hydrofluorocarbon-based coolant, and the second lubricating oil is preferably ester or ether oil.