Title:
INTERNAL COMBUSTION ENGINE EXHAUST PURIFICATION SYSTEM AND INTERNAL COMBUSTION ENGINE EXHAUST PURIFICATION METHOD
Document Type and Number:
Japanese Patent JP2020143610
Kind Code:
A
Abstract:
To provide an internal combustion engine exhaust purification system and an internal combustion engine exhaust purification method capable of preventing ammonia from flowing into an exhaust passage at a downstream side of a selective reduction catalyst device.SOLUTION: An internal combustion engine exhaust purification system comprises: an anterior NOx amount acquisition device which acquires an amount of NOx in exhaust flowing into a selective reduction catalyst device; and a posterior NOx amount detection device which detects NOx in the exhaust flowing out of the selective reduction catalyst device, ammonia in the flowing exhaust with detection sensitivity lower than the same to the detected NOx, and the amount of NOx together with the amount of ammonia in the exhaust flowing out of the selective reduction catalyst. When a value D obtained by subtracting a detection value of the posterior NOx amount detection device from an acquired value of the anterior NOx amount acquisition device is determined to be less than a first set threshold D1 which is a negative threshold (S30: Yes), injection of a reduction agent through a reduction agent injection device is stopped until the difference value D becomes equal to or larger than a second set threshold D2 which is a positive threshold (S60: Yes).SELECTED DRAWING: Figure 2
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Inventors:
FUJII KENJI
Application Number:
JP2019039909A
Publication Date:
September 10, 2020
Filing Date:
March 05, 2019
Export Citation:
Assignee:
ISUZU MOTORS LTD
International Classes:
F01N3/20; F01N3/08; F01N3/24; F02D43/00; F02D45/00
Attorney, Agent or Firm:
Seiryu International Patent Service Corporation
Takayoshi in the daytime
Masao Sakaizawa
Yuki Yamada
Takayoshi in the daytime
Masao Sakaizawa
Yuki Yamada