To provide a Rankine cycle device capable of securing reliability of an expander and a pump and also making mechanical energy output by the expander as large as possible.
A Rankine cycle device 10 includes a first pressure sensor 72 which detects low-pressure-side pressure as the pressure of a working fluid from an exit of an expander 20 to an entrance of a pump 40. In a working fluid circuit 11, a bypass passage 71 is arranged which has one end connected to a first passage 21 and the other end connected to a third passage 23, and the bypass passage 71 is provided with a flow rate control valve 71a which changes the flow rate of a working fluid flowing to the bypass passage 71 and a heat exchanger 50. Then a control part 75 controls high-pressure-side pressure by changing the bypass flow rate of the working fluid in the first passage 21 to the third passage 23.
IGUCHI MASAO
MORI HIDEFUMI
ENOSHIMA FUMINOBU
Makoto Onda