To prevent a knocking or the generation of NOx caused by an increase in intake temperature by interposing a cooling means provided with a condensed water removing means in an EGR passage in an engine with a supercharger.
A cooler 3 is interposed in an EGR passage L1 for connecting the downstream of a turbine(T) to the upstream of a compressor(C) and is provided with a drain 4. A refrigerant circuit 5 in which a second flow adjusting valve V2 is interposed is connected to a thermal load. The EGR passage L1 has a flow adjusting valve V1 provided in the upstream of the cooler 3 and a temperature sensor St for detecting the temperature(t) of EGR gas and a pressure sensor Sp for detecting the pressure(p) of EGR gas which are provided in the downstream of the cooler 3. If the temperature(t) exceeds a specified range, the opening of the first flow adjusting valve V1 is fixed by a control unit CU, that is, the flow of EGR is fixed, and the opening of the second flow adjusting valve V2 is enlarged to increase the flow of the refrigerant, which decreases the temperature(t).
SHOJI FUJIO
CHIYOU FUKUEI
OKAMOTO KAZUHISA
