Refrigeration apparatus for oil and defrost control

A refrigeration apparatus configured from a parallel connection of a plurality of outdoor units to an indoor unit, the refrigeration apparatus comprising:

• a refrigerant circuit capable of executing at least an air-warming operation and configured from a connection of:
• an indoor heat exchanger provided to the indoor unit;
• and
• an outdoor heat exchanger, a compressor, and a switching valve provided to each of the plurality of outdoor units;
• and
• a controller including at least one processor programmed to selectively execute one of the following when a predetermined defrosting condition is fulfilled during execution of the air-warming operation:
• an alternating defrost mode in which an operation, which is performed with the switching valves having been connected such that at least one of the outdoor heat exchangers of the plurality of outdoor units is caused to function as evaporator, while one or more outdoor heat exchangers of the rest of the plurality of outdoor units is designated as a component to be defrosted and thereby caused to function as condenser, is executed, wherein the one or more outdoor heat exchangers designated as a component to be defrosted is switched during the alternating defrost mode;
• and
• a reverse-cycle defrost mode executed with the switching valves having been connected such that the outdoor heat exchangers of the outdoor units are caused to function as condensers and the indoor heat exchanger is caused to function as an evaporator,
• wherein the at least one processor is further programmed to, when the predetermined defrosting condition has been fulfilled, selectively execute one of the reverse-cycle defrost mode and the alternating defrost mode on a basis of whether or not a predetermined outflow condition pertaining to a determined value of an outflow integrated quantity of refrigerator oil has also been fulfilled, such that
• the reverse-cycle defrost mode is executed if the predetermined outflow condition has been fulfilled, and
• the alternating defrost mode is executed if the predetermined outflow condition has not been fulfilled.