| 摘要 |
<p>An exhaust gas purifying system includes an exhaust passage (2), an oxidation catalyst (3), a selective catalytic reduction catalyst (5), a urea water supply device (7), a first heating mechanism (8) and a controller (10). The exhaust gas discharged from an internal combustion engine (1) flows through the exhaust passage (2). The oxidation catalyst (3) for oxidizing nitrogen monoxide contained in the exhaust gas to nitrogen dioxide is disposed in the exhaust passage (2). The selective catalytic reduction catalyst (5) is disposed downstream of the oxidation catalyst (3). The urea water supply device (7) supplies urea water into the exhaust passage (2) at the upstream of the selective catalytic reduction catalyst (5). The first heating mechanism (8) heats the oxidation catalyst (3). The controller (10) controls the first heating mechanism (8) to adjust the temperature of the oxidation catalyst (3) such that molar ratio between nitrogen monoxide and nitrogen dioxide in the exhaust gas flowing into the selective catalytic reduction catalyst (5) become one to one.</p> |
