Patent ID: 8544270

Claim:
A waste heat recovery system of an internal combustion engine, comprising: a Rankine cycle circuit provided with a pump, a heat exchanger that heats heat-transfer media by using heat generated in an internal combustion engine and thus adds superheat to the heat-transfer media, an expander, and a condenser, which are interposed in a circulation path of the heat-transfer media; power-transmitting means that transmits the power of a rotary shaft of the expander to a rotary shaft of the internal combustion engine; a flow-rate regulating valve that is interposed in an expander upstream section of the circulation path, which extends between the heat exchanger and an inlet of the expander, and is configured to regulate a flow rate of the heat-transfer media in the expander upstream section; a high-pressure sensor that detects pressure of the heat-transfer media within the heat exchanger; and a controller that controls the operation of the pump and the flow-rate regulating valve, wherein: the controller has at least determination means that makes a determination as to whether it is necessary to increase the pressure of the heat-transfer media in the heat exchanger, on the basis of the pressure detected by the high-pressure sensor; when the at least determination means determines that it is necessary to increase the pressure of the heat-transfer media in the heat exchanger, the flow-rate regulating valve is activated to start regulating the flow rate of the heat-transfer media while the pump remains working; and the flow-rate regulating valve is made to continue to regulate the flow rate of the heat-transfer media at least until the at least determination means determines that it is not necessary to increase the pressure of the heat-transfer media in the heat exchanger, and then the regulation is terminated.