Refrigeration apparatus

A refrigeration apparatus comprising:

• a compressor;
• a heat-source-side heat exchanger operable as an evaporator or a radiator of a refrigerant;
• a usage-side heat exchanger operable as an evaporator or a radiator of the refrigerant;
• and
• a controller programmed to perform a defrost operation,
• the heat-source-side heat exchanger being disposed inside a heat source unit having
• an exhaust port and an outdoor fan in an upper part, and
• an intake port in a side part,
• the heat-source-side heat exchanger being configured so as to suction air into an interior from the intake port and to exhaust air out to an exterior from the exhaust port,
• the heat-source-side heat exchanger being disposed so as to face the intake port, and
• the heat-source-side heat exchanger being divided so as to include a first heat-source-side heat exchanger and a second heat-source-side heat exchanger on a lower side of the first heat-source-side heat exchanger,
• a first heat-source-side flow rate adjusting valve, an opening degree of which is adjustable, being connected to a liquid side of the first heat-source-side heat exchanger such that the first heat-source-side flow rate adjusting valve is located downstream of the first heat-source-side heat exchanger in a flow of the refrigerant in a case of operating as a radiator of the refrigerant,
• a second heat-source-side flow rate adjusting valve, an opening degree of which is adjustable, being connected to a liquid side of the second heat-source-side heat exchanger such that the second heat-source-side flow rate adjusting valve is located downstream of the second heat-source-side heat exchanger in the flow of the refrigerant in a case of operating as a radiator of the refrigerant,
• Cv values of the first heat-source-side flow rate adjusting valve and the second heat-source-side flow rate adjusting valve in a state of the opening degrees of the first heat-source-side flow rate adjusting valve and the second heat-source-side adjusting valve being fully open being determined so that the refrigerant flows readily to the first heat-source-side heat exchanger and the refrigerant does not flow readily to the second heat-source-side heat exchanger, in comparison with a heat transfer area ratio between the first heat-source-side heat exchanger and the second heat-source-side heat exchanger,
• the defrost operation being performed in order
• to defrost the first and second heat-source-side heat exchangers by stopping the outdoor fan and causing the first and second heat-source-side heat exchangers to operate as radiators of the refrigerant, and
• to cause the usage-side heat exchanger to operate as an evaporator of the refrigerant when frost forms on the first and second heat-source-side heat exchangers operating as evaporators of the refrigerant, and
• the opening degrees of the first and second heat-source-side flow rate adjusting valves being controlled in the defrost operation so as to achieve a defrost flow rate ratio at which more of the refrigerant flows to the second heat-source-side heat exchanger than during an air-cooling operation in which the first and second heat-source-side heat exchangers operate as radiators of the refrigerant and the usage-side heat exchanger operates as an evaporator of the refrigerant.