Control device for an internal combustion engine preventing condensation of intake gas in an intercooler

摘要

A control device for an internal combustion engine includes an intake gas compressor, a cooling water circuit, an intercooler and an EGR device. An ECU is configured to: (a) control the temperature, of the cooling water of the intercooler to a target temperature in a specified external air state in which an external air temperature and an external air humidity are a specified temperature and a specified humidity, the target temperature being the temperature of the cooling water of the intercooler required for ensuring a specified performance in the specified external air state; and (b) control the EGR device based on an EGR rate mapping of the EGR rate. The EGR rate mapping being set so that a dew point of gas flowing into the intercooler does not exceed the target temperature.

主权项

1. A control device for an internal combustion engine, the control device comprising:
a compressor arranged in an intake passage of the internal combustion engine, the compressor configured to supercharge gas flowing in the intake passage; a first cooling water circuit configured to circulate cooling water; an intercooler arranged in the intake passage closer to a downstream side as compared with the compressor, the intercooler configured to exchange heat between the gas flowing in the intake passage and the cooling water circulated in the first cooling water circuit; an EGR device configured to adjust an EGR rate of EGR gas for supplying a portion of exhaust gas flowing in an exhaust passage of the internal combustion engine to the intake passage closer to an upstream side as compared with the intercooler, an ECU configured to: (a) control the temperature of the cooling water of the intercooler to a target temperature in a specified external air state in which an external air temperature and an external air humidity are a specified temperature and a specified humidity, the target temperature being the temperature of the cooling water of the intercooler required for ensuring a specified performance in the specified external air state; and (b) control the EGR device based on an EGR rate mapping in which the EGR rate is set according to a relationship with parameters for determining an operating state of the internal combustion engine, the EGR rate mapping configured to set the EGR rate so that a dew point of cooler inflow gas flowing into the intercooler does not exceed the target temperature when the EGR gas is introduced by using the EGR device.