Steam temperature control system for evaporator

摘要

In order to control an actual temperature of a vapor generated by en evaporator (3) for heating water by an exhaust gas from an engine (1) to a target vapor temperature by varying the amount of water supplied from a supplied-water amount control injector (7), a control unit (11) controls the amount of water supplied in a feedforward manner in accordance to an engine rotational speed and an intake negative pressure and controls the amount of water supplied in a feedback manner based on a difference between the actual vapor temperature and the target vapor temperature. It is possible to control the actual temperature of the vapor generated by the evaporator (3) to the target vapor temperature with a high accuracy even in a transient state of the engine (1) by correcting a feedforward control value using at least one of a fuel-cut control signal, an ignition-retarding control signal, an EGR control signal and an air fuel ratio control signal which are parameters indicating a burned state of the engine (1).