Method for increasing the efficiency of a catalyst in a diesel engine
AssigneeC.R.F. Societa Consortile per Azioni
InventorsGiovanni Maria Rossi Sebastiano, Silvio Canale
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Abstract
An injection method applicable to engines featuring a Denox catalyst for reducing the nitric oxide content of exhaust gas. In addition to the main injection phase, the method presents a post-injection phase predominantly performed during the exhaust stroke of the engine, so that the diesel fuel injected does not contribute--or only to a very limited extent--towards combusion, but is supplied directly to the Denox catalyst to increase its efficiency. The method involves no alterations to the injection system, by virtue of post-injection being controlled and optimized by the central unit controlling injection as a whole.
Claims21
A method of activating a Denox catalyst of a diesel engine having a rail injection system, said method comprising the steps of:
- injecting diesel fuel during a main injection phase;
- and
- injecting diesel fuel during an auxiliary post-injection phase, wherein said auxiliary post-injection phase is carried out in the range between just prior to the exhaust stroke and the top dead center of the engine at the end of the exhaust stroke, at least a portion of said auxiliary post-iniection phase being carried out during the exhaust stroke.
A method of activating a Denox catalyst in an exhaust line downstream of a diesel engine, said diesel engine having at least one cylinder and having a rail injection system which injects a first quantity of diesel fuel into said at least one cylinder during a main injection phase, said method comprising:
- injecting a second quantity of diesel fuel into said at least one cylinder during an auxiliary post-injection phase in the range between just prior to the exhaust stroke and the top dead center of the engine at the end of the exhaust stroke such that at least a portion of said second quantity of diesel fuel does not combust and reaches said Denox catalyst in an unburned state, at least a portion of said auxiliary post-injection phase being carried out during the exhaust stroke.
Dependencies are inferred from the claim text.