CONTROL METHOD FOR HEAT EXCHANGE SYSTEM AND CONTROL DEVICE FOR HEAT EXCHANGE SYTSTEM

摘要

A heat exchange system control method for controlling a heat exchange system that is provided with a heat exchange passage, which has a heat exchanger for exchanging heat between an exhaust gas and a liquid in an exhaust passage of an engine, a bypass passage, which bypasses the heat exchanger, and a first flow rate adjustment mechanism, which adjusts the exhaust gas flow rate in the heat exchange passage and the bypass passage, and that is further provided with an exhaust gas recirculation passage, which recirculates exhaust gas from an outlet side of the heat exchanger in the heat exchange passage to an intake passage of the engine, a second flow rate adjustment mechanism, which adjusts the flow rate of the exhaust gas passing through the exhaust gas recirculation passage, and a control unit, which controls the first flow rate adjustment mechanism and the second flow rate adjustment mechanism. In this control method, when the flow rate of the exhaust gas flowing into the heat exchanger is changed, the control unit, while operating the first flow rate adjustment mechanism, operates the second flow rate adjustment mechanism in a direction which cancels out changes to the flow rate of the exhaust gas passing through the exhaust gas recirculation passage that accompanies the operation of the first flow rate adjustment mechanism.