Patent ID: 8484989

Claim:
A refrigeration system comprising: a refrigerant circuit including a compressor and a cooling heat exchanger both connected therein, the refrigerant circuit operating in a refrigeration cycle by circulating refrigerant therethrough; and an internal fan for sucking in air from an air inlet provided in an upper part of an interior of a cold storage to allow the air to flow through the cooling heat exchanger and then blowing off the air into the cold storage from an air outlet provided in a lower part of the interior of the cold storage, wherein the refrigeration system further comprises a capacity regulator for regulating the cooling capacity of the cooling heat exchanger to keep the blow-off-side air temperature in the cold storage at a set value, the refrigeration system is configured to be capable of performing an energy saving operation including: a first action in which the compressor and the internal fan are driven while the capacity regulator regulates the cooling capacity of the cooling heat exchanger; a second action in which, when the blow-off-side air temperature is kept at the set value in the first action, the capacity regulator increases the cooling capacity of the cooling heat exchanger to lower the blow-off-side air temperature to a lower limit of a desired temperature range containing the set value, and then the compressor and the internal fan are stopped; and a third action in which, when the blow-off-side air temperature after the second action rises to an upper limit of the desired temperature range, the first action is restarted, the energy saving operation is configured so that when the suction-side air temperature in the air inlet of the interior of the cold storage after the second action rises to a predetermined limit value, the internal fan is activated at a lower air flow rate than in the first action, and a predetermined period of time is defined, and the energy saving operation is configured so that the set value of the blow-off-side air temperature is lowered in every predetermined period of time.