Patent ID: 7454910

Claim:
A waste heat recovery system of a heat source that is cooled by a circulation of a thermal medium, the system comprising: a cooling heat exchanger for cooling the thermal medium, disposed in a thermal medium circulating circuit through which the thermal medium is circulated between the cooling heat exchanger and the heat source; and a Rankine cycle including a heater that performs heat exchange between an operation fluid and the thermal medium heated by the heat source so as to heat the operation fluid, and an expansion device that expands the operation fluid, which is heated by the heater to be evaporated, so as to generate a driving power, wherein the heater is arranged in parallel with the cooling heat exchanger in such a manner that the thermal medium flowing through the heater bypasses the cooling heat exchanger, the system further comprising: a temperature sensor for sensing an actual temperature of the thermal medium; a first pumping unit disposed in the thermal medium circulating circuit to circulate the thermal medium; and a first switching unit disposed in the thermal medium circulating circuit to adjust a flow distribution between a flow amount of thermal medium to be introduced into the heater and a flow amount of thermal medium passing through the cooling heat exchanger, at least one of a discharge capacity of the first pumping unit and the flow distribution distributed by the first switching unit being variable; a control unit for controlling at least one of the first pumping unit and the first switching unit based on a temperature of thermal medium discharged from the heat source in the thermal medium circulating circuit, wherein the control unit includes means for calculating a difference between a target thermal medium temperature and the actual temperature of the thermal medium discharged from the heat source; when the difference is less than a first threshold, the control unit determines that a temperature of the heat source is excessively low, and controls the first switching unit so as to decrease a distribution amount of thermal medium flowing into the cooling heat exchanger when the distribution amount is not substantially zero; and when the difference is greater than a second threshold, which is higher than the first threshold, the control unit determines that the temperature of the heat source is excessively high, and controls the first pumping unit so as to increase the discharge capacity when the first pumping unit has an extra discharge capacity.