摘要:
An exhaust gas treatment system (14) includes a selective catalytic reduction (SCR) catalyst (38) and a dosing control (80) responsive to exhaust gas operating conditions for controlling the dosing rate of a reductant such as aqueous urea into the exhaust stream. The dosing control is configured to reduce the dosing rate when either a sudden increase in the exhaust mass air flow is detected or when an exhaust gas temperature gradient is in an increasing state. The dosing control is also configured to shut-off dosing when a measured ammonia concentration level exceeds an ammonia slip trip level, provided that the exhaust gas temperature gradient is also in an increasing state.
摘要:
A sensor package (10) and method of making the same is disclosed in which the sensor package (10) includes a sensor component (12) for electromagnetic sensing having a sensor body (16) with a sensor tip (18) at one end. A sensor housing (24) having a cavity for receiving the sensor component (12) is disposed in a substrate and is aligned with an object to be sensed. The housing (24) further includes a snap-fit interface with the sensor component (12) that is configured to admit and secure the sensor tip (18) during assembly thereof. A bracket (26) is mechanically fixable to the substrate at a first end and is in operable communication with the sensor tip (18) at a second end. The bracket (26) is configured to bias the sensor tip (18) towards the object to be sensed for elimination of an internal air gap (84) between the sensor tip (18) and housing (24) formed during assembly thereof.
摘要:
An exhaust gas treatment system (14) includes a selective catalytic reduction (SCR) catalyst (38) and a dosing control (80) responsive to exhaust gas operating conditions for controlling the dosing rate of a reductant such as aqueous urea into the exhaust stream. The dosing control is configured to reduce the dosing rate when either a sudden increase in the exhaust mass air flow is detected or when an exhaust gas temperature gradient is in an increasing state. The dosing control is also configured to shut-off dosing when a measured ammonia concentration level exceeds an ammonia slip trip level, provided that the exhaust gas temperature gradient is also in an increasing state.
摘要:
A fuel tank interface (10) assembly is provided. The assembly provides interface and control to a plurality of different types of components (e.g., 22, 24, 26, 28). Some of the components may be situated inside the tank. A connector (52) is sealingly mounted through a single opening in the tank and is configured to provide at least two electrical leads for each different type of component in the tank. A unitary control unit (50) is electrically coupled to the connector and is configured to provide control to each of the plurality of different type of components through each of the at least two electrical leads.
摘要:
A planar oxygen sensor (1) having a pump cell (2), a reference cell (4), a sensor chamber (6) and a heating device (8), a ground plane electrode (10) including a sensing portion (18) having a first sense lead (20) and a second sense lead (22) and a measuring portion (24) having a first measuring lead (26) and a second measuring lead (28), wherein the first measuring lead (26) and the second measuring lead (28) have increased surface area relative to said sensing portion (18) such that the resistance between the first measuring lead (26) and the second measuring lead (28) is reduced and wherein the first measuring lead (26) is disposed so as to be communicated with the first sense lead (20) and the second measuring lead (28) is disposed so as to be communicated with the second sense lead (22). A method for measuring the temperature in a planar oxygen sensor (1) having a pump cell (2), a reference cell (4), a sensor chamber (6), a heating device (8) and a ground plane electrode (10) that includes a sensing portion (18) having a first sense lead (20) and a second sense lead (22) and a measuring portion (24) having a first measuring lead (26) and a second measuring lead (28). The method includes obtaining a temperature measurement device (52), communicating the temperature measurement device (52) with the first measuring lead (26) and the second measuring lead (28), operating the planar oxygen sensor (1) so as to cause the heating device (8) to heat the planar oxygen sensor (1), and measuring the resistance between the first measuring lead (26) and the second measuring lead (28).
摘要:
In an internal combustion engine system having an exhaust aftertreatment system including a selective catalytic reduction (SCR) catalyst (38), diagnostic methods involve the intrusive perturbation of a target surface coverage parameter theta to determine the state of health of the SCR catalyst (38) or an ammonia concentration sensor (60). An adaptive learning block adapts the target theta based on the use of NH 3 sensing feedback from a mid-brick positioned ammonia concentration sensor (60) to pull in system variation. A further diagnostic monitors the amount of adaptation and when the adaptive learning excessively learns, the diagnostic assumes that some system-level degradation must have occurred and the diagnostic will notify the overall emissions control monitor.
摘要:
In an internal combustion engine system having an exhaust aftertreatment system including a selective catalytic reduction (SCR) catalyst (38), diagnostic methods involve the intrusive perturbation of a target surface coverage parameter theta to determine the state of health of the SCR catalyst (38) or an ammonia concentration sensor (60). An adaptive learning block adapts the target theta based on the use of NH 3 sensing feedback from a mid-brick positioned ammonia concentration sensor (60) to pull in system variation. A further diagnostic monitors the amount of adaptation and when the adaptive learning excessively learns, the diagnostic assumes that some system-level degradation must have occurred and the diagnostic will notify the overall emissions control monitor.