Abstract: A reversed Rankine cycle system, wherein a vortex tube is disposed between the compressor and the condenser in a reversed Rankine cycle, the superheated vapors of coolant at a high pressure discharged from the compressor are taken out while separating them by the vortex tube into higher and lower temperature components through energy separation to render most of the portion thereof into superheated vapors of coolant at a higher temperature and the remaining portions into vapors of coolant at a lower temperature respectively, and the superheated vapors of coolant separated to the higher temperature side are introduced into the circuit on the higher temperature side of the condenser and condensated therein, while the vapors of coolant separated to the lower temperature side are recycled to the system, of the cycle, preferably, to the circuit on the lower temperature side of the condenser.