Waste heat recovering apparatus for an engine

摘要

The absence or shortage of a heat transfer medium can be detected without any time lag. While the medium is circulated through a water jacket and an exhaust gas heat exchanger which receives heat from the exhaust gas, heat generated by the engine can be recovered. A first sensor is provided at a waste heat recovering location in a circulation path of the medium. A second sensor is provided at a downstream side of sensor. When the medium is absent, a difference in measured temperature develops between sensor and sensor. A heat transfer medium shortage signal is outputted when the difference in the measured temperature between the first sensor and the second sensor exceeds a predetermined reference level.