发明名称 |
Method for diagnosing a selective catalytic reduction catalyst |
摘要 |
A method for diagnosing a selective catalytic reduction (SCR) catalyst of an exhaust aftertreatment system of an internal combustion engine includes ensuring that a SCR catalyst NH3 storage level is substantially below the current maximal NH3 storage capacity of the SCR catalyst, initiating over-injection of reductant by the injector, stopping reductant injection upon registering, by the exhaust gas sensor, an increasing NOx+NH3 emission level and an NOx+NH3 emission level exceeding a predefined threshold value, and when the reduction injection is stopped recording an output signal of the exhaust gas sensor until an indication of a minimal or negligible SCR catalyst NH3 storage level is determined, and calculating a SCR catalyst NH3 storage capacity on the basis of the recorded output signal. |
申请公布号 |
US9492788(B2) |
申请公布日期 |
2016.11.15 |
申请号 |
US201214388373 |
申请日期 |
2012.03.29 |
申请人 |
Volvo Construction Equipment AB |
发明人 |
Gaudin Bruno |
分类号 |
B01D53/94;G01N33/00;F01N3/20;F01N9/00;F01N11/00;F01N3/10;F01N13/00 |
主分类号 |
B01D53/94 |
代理机构 |
WRB-IP LLP |
代理人 |
WRB-IP LLP |
主权项 |
1. A method for determining an ammonia (NH3) storage capacity of a selective catalytic reduction (SCR) catalyst of an exhaust aftertreatment system of an internal combustion engine, wherein the exhaust aftertreatment system comprises a SCR catalyst, an reductant injector arranged upstream of the SCR catalyst for injecting a reductant into an exhaust gas, and an exhaust gas sensor arranged downstream of the SCR catalyst, which exhaust gas sensor being cross-sensitive to nitrogen oxide (NOx) and NH3 present within the exhaust gas leaving the SCR catalyst, wherein the method comprises the steps of:
ensuring that a SCR catalyst NH3 storage level is substantially below a current maximal NH3 storage capacity of the SCR catalyst; initiating over-injection of reductant by the injector; stopping reductant injection in response to registering, by the exhaust gas sensor, an increasing NOx+NH3 emission level and an NOx+NH3 emission level exceeding a predefined threshold value, and when the reduction injection is stopped recording an output signal of the exhaust gas sensor until an indication of a minimal negligible SCR catalyst NH3 storage level is determined; and calculating a SCR catalyst NH3 storage capacity on a basis of the recorded output signal, wherein the storage capacity is calculated by integrating a difference between an estimated or recorded level of nitrogen oxide (NOx) having entered the SCR catalyst and a recorded level of nitrogen oxide (NOx) having been emitted from the SCR catalyst. |
地址 |
Eskilstuna SE |