SELECTIVE CATALYTIC REDUCTION SYSTEM

摘要

An embodiment of the present invention relates to a selective catalytic reduction system including: a main fluid passage which allows exhaust gas to pass therethrough; a reactor provided on the main fluid passage and having a catalyst therein; a sooth blower which sprays air to remove soot from the catalyst; a first opening/closing unit installed on the main fluid passage to switch the flow of the exhaust gas introduced into the reactor; a second opening/closing unit installed on the main fluid passage to switch the flow of the exhaust gas passing through the reactor; a circulation fluid passage which connects one point between the first opening/closing unit and a front end of the reactor with an opposite point between the second opening/closing unit and a rear end of the reactor; a heating unit which raises the temperature of the exhaust gas passing through the circulation fluid passage; an oxygen sensor which detects oxygen concentration inside the circulation fluid passage; and a control unit which controls the first and second opening/closing members and the heating unit which performs a catalyst reproduction operation. The control unit actuates the soot blower to increase oxygen concentration of the circulation fluid passage when an oxygen concentration value detected by the oxygen sensor is less than a preset oxygen concentration value.