WASTE HEAT RECOVERY SYSTEM

Connected in parallel to an expander (3) and a condenser (4) of a Rankine cycle (6) are n sets (S) each of which comprises a different expander (E) and a different condenser (C). Moreover, operation stopping means (B 1 -B n ) are provided for stopping operations of the expanders (E 1 -E n ) in the sets (S 1 -S n ) connected in parallel, and a pressure sensor (10) and a temperature sensor (11) are installed respectively in an inlet and outlet of an evaporator (2). An ECU (12) sets or releases at least one of the operation stopping means (B 1 -B n ) such that a measured value (T) of the temperature sensor (11) reaches a prescribed temperature value (Ts) which is equal to or less than a thermal decomposition temperature of a refrigerant (5) and which is set in advance, and the ECU (12) controls a rotational speed of a refrigerant pump (1) such that a measured value (P) of the pressure sensor (10) reaches a prescribed pressure value (Ps) set in advance.