Patent ID: 9624879
Date: 2017-04-18
CPC Classifications: F01N,F02B,F02D,F02M,Y02T

Claim:
1. A condensed water treatment device for an internal combustion engine, the condensed water treatment device being applied to the internal combustion engine comprising: a selective-reduction NOx catalyst which is provided on an exhaust passage and reduces NOx to purify exhaust gas by ammonia; an additive supplying valve which supplies additive which is ammonia or a precursor of ammonia to the exhaust passage at an upstream side of the selective-reduction NOx catalyst; and an EGR device which is provided with an EGR cooler where condensed water is generated, an EGR passage where the exhaust gas taken out from the exhaust passage at a downstream side of the selective-reduction NOx catalyst leads to an intake system as EGR gas, and an EGR valve to adjust flow rate of the exhaust gas to be led to the intake system, wherein the condensed water treatment device comprises: a condensed water tank which stores condensed water generated in the EGR device; a condensed water supplying mechanism which is provided with a condensed water passage connecting the condensed water tank and the intake system or an exhaust system to supply the condensed water stored in the condensed water tank to the internal combustion engine or a related device relating to the internal combustion engine; and a computer which functions by executing a computer program as an additive supply controlling device which is configured to control the additive supplying valve to increase, in a case where pH of the condensed water stored in the condensed water tank is smaller than a threshold value, a supply quantity of the additive supplied to the exhaust passage so that the supply quantity is larger than the supply quantity of a case where the pH of the condensed water stored in the condensed water tank is equal to or more than the threshold value, wherein the additive supply controlling device is further configured to control the additive supplying valve to execute decrease offset of supply quantity of the additive in a decreasing quantity period following after acceleration of the internal combustion engine ends.