In an ejector cycle having an ejector, a decompression amount of refrigerant
between
a gas-liquid separator and an evaporator is adjusted by a differential pressure
control valve, so that a pressure increasing amount in a pressure increasing portion
of the ejector is controlled to be equal to or lower than a predetermined amount.
Therefore, a suction pressure of refrigerant to be sucked to the compressor can
be restricted from being excessively increased in accordance with the increase
of the pressure increasing amount in the ejector, and it can prevent heat radiating
capacity of a radiator from being decreased. Thus, a sufficient cooling capacity
can be always obtained in the ejector cycle.
