HEAT CYCLE SYSTEM

To provide a heat cycle system that enables both of waste heat recovery from an engine and warming-up of the engine in an efficient manner.SOLUTION: A heat cycle system 1 includes a cooling circuit 3 and a Rankine cycle circuit 5 having an organic medium circulating therethrough. The Rankine cycle circuit 5 includes an evaporator 52, an expander 53 and a condenser 54. A control device 7 executes a warming-up mode of causing the organic medium to circulate through the condenser 54, the expander 53 and the evaporator 52 in this order before warming-up the engine 2, and executes a waste heat recovery mode of causing the organic medium to circulate through the evaporator 52, the expander 53 and the condenser 54 in this order after warming-up the engine 2. The control device 7 compresses the organic medium that has passed through the condenser 54 and supplies the compressed organic medium to the evaporator 52 by supplying energy to the expander 53 in the warming-up mode, and recovers the energy generated in the expander 53 by decompressing the organic medium that has passed through the evaporator 52 by using the expander 53 in the waste heat recovery mode.SELECTED DRAWING: Figure 1 【課題】エンジンの廃熱回収及び暖機を何れも効率的に行うことができる熱サイクルシステムを提供すること。【解決手段】熱サイクルシステム１は、冷却回路３と、有機媒体が循環するランキンサイクル回路５と、を備える。ランキンサイクル回路５は、蒸発器５２と、膨張機５３と、凝縮器５４と、を備える。制御装置７は、エンジン２の暖機前には有機媒体を凝縮器５４、膨張機５３、及び蒸発器５２の順で循環させる暖機モードを実行し、エンジン２の暖機後には有機媒体を蒸発器５２、膨張機５３、及び凝縮器５４の順で循環させる廃熱回収モードを実行する。制御装置７は、暖機モードでは、膨張機５３にエネルギを供給することにより凝縮器５４を経た有機媒体を圧縮して蒸発器５２に供給し、廃熱回収モードでは、蒸発器５２を経た有機媒体を膨張機５３で減圧させることによりこの膨張機５３で発生したエネルギを回収する。【選択図】図１