| 摘要 |
A diesel exhaust gas system includes a diesel particulate filter (DPF), a trap for nitrogen oxides (LNT), a hydrocarbon catalytic reformer for generating reformate, and an air supply. A method for controlling the rate of burn of soot in a DPF limits the oxygen percentage in the exhaust to about 6%. The LNT may be located ahead of the DPF in the exhaust line. Reformate is directed with exhaust through the LNT. The second flow of air cools the exhaust gas and thereby prevents overheating of the DPF substrate. The DPF also may be located ahead of the LNT. Reformate is controllably combusted by the second air flow in the DPF, reducing the oxygen percentage to about 6%, thus limiting the rate at which soot in the DPF can burn and thereby preventing overheating of the DPF substrate. |
