Abstract:
The present invention relates to a method and apparatus for flow rate monitoring, the method comprising: obtaining a first signal, which indicates a pressure at which a reductant, used to treat exhaust gas of an engine of a vehicle, is supplied to a reductant injection unit by a reductant supply unit of the vehicle; acquiring a first frequency domain signal corresponding to the first signal; and determining whether an actual injection flow rate of the reductant injection unit is in an abnormal state, based on whether an amplitude, at an injection frequency of the reductant injection unit, of the first frequency domain signal is outside a target amplitude interval. The method and apparatus can check whether the actual injection flow rate of the reductant injection unit of the vehicle is in an abnormal state in a simple manner.
Abstract:
A selective catalytic reduction (SCR) catalyst is disposed in an exhaust gas system of an internal combustion engine. A reductant injector is coupled to the exhaust gas stream at a position upstream of the SCR catalyst, and first and second NOx sensors provide NOx measurements upstream of and downstream of the SCR catalyst, respectively. A system and method is disclosed for operating the system to determine a NOx amount and/or a NH3 slip amount downstream of the SCR catalyst by decoupling NOx-NH3 measurements from the output of the second NOx sensor to provide control of the reductant injection amount.
Abstract:
Systems and methods to selectively control plurality of dosing modules may include receiving data indicative of an exhaust flow rate. An amount of reductant to be dosed may be determined based, at least in part, on the data indicative of the exhaust flow rate. A decomposition delay time may also be determined and a first dosing module and a second dosing module may be selectively activated. The first dosing module may be selectively activated at a first time and the second dosing module is selectively activated at a second time. The second time is based on the first time and the determined decomposition delay time.
Abstract:
An internal combustion engine which is provided with a hydrocarbon feed valve (15) arranged in an engine exhaust passage. When injection control for injecting hydrocarbons from the hydrocarbon feed valve (15) for exhaust treatment is stopped, to prevent the hydrocarbon feed valve (15) from clogging, hydrocarbons for preventing clogging are injected from the hydrocarbon feed valve (15) when the engine is not discharging soot, that is, when the feed of fuel to the inside of the combustion chamber (2) is stopped and, after hydrocarbons for preventing clogging are injected once, the injection of hydrocarbons for preventing clogging from the hydrocarbon feed valve (15) is stopped until injection control for exhaust treatment is started.
Abstract:
An exhaust gas purification apparatus for an internal combustion engine (1), the exhaust gas purification apparatus includes a catalyst (40), a reducing agent supply mechanism (200), a dispersion plate (60), and a control unit (80). The catalyst (40) is configured to purify exhaust gas by adding a reducing agent. The reducing agent supply mechanism (200) is configured to add the reducing agent into an exhaust passage (26). The dispersion plate (60) is provided in the exhaust passage (26) and is configured to disperse the reducing agent upstream of the catalyst (40). The control unit (80) is configured to execute addition of the reducing agent by the reducing agent supply mechanism (200), and the control unit is configured to prohibit the addition of the reducing agent when a temperature of the dispersion plate (60) is lower than a predetermined temperature.
Abstract:
An exhaust gas purification device, which purifies exhaust gas in first and second exhaust gas passages (20A, 20B) extending from an internal combustion engine, is equipped with: a convergence passage (22) extending from the area of convergence of the first and second exhaust gas passages; a first sub NOx catalyst (25A) provided in the first exhaust gas passage; a second sub NOx catalyst (25B) provided in the second exhaust gas passage; a main NOx catalyst (26) provided in the convergence passage; a first addition unit (30A) that adds an ammonia source with a first additive amount upstream from the first sub NOx catalyst so as to supply urea water to the first sub NOx catalyst; and a second addition unit (30B) that adds an ammonia source with a second additive amount upstream from the second sub NOx catalyst so as to supply urea water to the second sub NOx catalyst.