초록 ▼

A method and system for determining whether a desired amount of hydrocarbon is actually injected into an engine exhaust to react with NOx in such engine exhaust. The reaction is facilitated with a catalyst downstream of the hydrocarbon injection. The method and system measure a first temperature dif

A method and system for determining whether a desired amount of hydrocarbon is actually injected into an engine exhaust to react with NOx in such engine exhaust. The reaction is facilitated with a catalyst downstream of the hydrocarbon injection. The method and system measure a first temperature difference across the catalyst during the reaction. The first temperature difference is compared with an expected temperature difference across the catalyst during the reaction. The difference in exotherm is used to adjust the injected HC quantity, and diagnose injector failures.

대표청구항 ▼

1. A method for determining whether a hydrocarbon injector used to inject hydrocarbons into an engine exhaust to react with NOx in such engine exhaust is degraded, such method comprising:measuring an exotherm during the reaction; determining an exotherm difference, such exotherm difference being a d

1. A method for determining whether a hydrocarbon injector used to inject hydrocarbons into an engine exhaust to react with NOx in such engine exhaust is degraded, such method comprising:measuring an exotherm during the reaction; determining an exotherm difference, such exotherm difference being a difference between the measured exotherm and an expected exotherm; integrating the exotherm difference over time; comparing the integration result with predetermined level to detect whether the injector is degraded.