EXHAUST GAS TREATMENT DEVICE, DIESEL ENGINE AND EXHAUST GAS TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To accurately provide respective catalysts with appropriate amounts of reducing agents when treating exhaust gas from a diesel engine, for reducing NOx, by using a plurality of reducing catalysts to reduce the NOx.SOLUTION: An exhaust gas treatment device 20 comprises: a NOx detection sensor 15; a first catalyst 25A installed on a first branch pipe 22A and a second catalyst 25B installed on a second branch pipe 22B; a first pressure sensor 27A and a second pressure sensor 27B which are arranged at respective upstream sides of the first catalyst 25A and the second catalyst 25B and detect pressure in the first branch pipe 22A and the second branch pipe 22B; and a control device 50 which obtains flow rates of exhaust gas EX flowing in the first branch pipe 22A and the second branch pipe 22B on the basis of detection values of the first pressure sensor 27A and the second pressure sensor 27B and also obtains amounts of reducing agents R to be provided with the first catalyst 25A and the second catalyst 25B from the obtained flow rates and a NOx concentration of the exhaust gas EX.