9609results about "Exhaust treatment electric control" patented technology

A method and system may be provided to perform a process for controlling NOx emissions of an target engine. In one embodiment of the invention, the process may include determining predicted NOx values based on a model reflecting a predetermined relationship between control parameters and NOx emissions, wherein the control parameters include ambient humidity, manifold pressure, manifold temperature, fuel rate, and engine speed associated with the engine. Further, the process may include adjusting the model based on a determination of whether the predicted NOx values meet a predetermined criteria associated with actual NOx values. The adjusted model may be stored in a memory associated with the engine whereby NOx emissions exhausted from the engine may be reduced based on virtual NOx emission values determined from the adjusted model.

One aspect of the invention relates to controlling the ammonia feed rate to an SCR reactor using a NOx sensor cross-sensitive to ammonia. The sensor, positioned downstream of the reactor, is interrogated by introducing a pulse in the ammonia feed rate. A positive response to a positive pulse indicates ammonia slip. A negative response to a positive pulse indicates NOx breakthrough. Another aspect of the invention related to a combination of feed-back and feed-forward control. Upon detecting ammonia slip, the controller enters into an ammonia slip recovery mode in which the ammonia feed rate is reduced for a period to restore the reactor's ammonia or NOx buffering capacity. After the recovery period, feed-forward control is restored, optionally with an updated control objective. A further aspect of the invention relates to a learning probabilistic model for feed-forward control trained according to the occurrence or non-occurrence of NOx breakthrough and ammonia slip.

Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

A method is presented for estimating an amount of ammonia stored in a urea-based SCR catalyst based on a dynamic model of the catalyst. The model takes into account chemical and physical properties of the catalyst, such as catalyst volume, the number of available ammonia storage cites, adsorption and desorption dynamics, as well as sulfur poisoning, thermal aging, and different catalyst operating temperatures, and generates the estimate based on a measured or estimated amount of NOx in an exhaust gas mixture upstream of the catalyst, an amount of reductant injected into the catalyst to facilitate NOx reduction, and on a measured value of NOx in an exhaust gas mixture downstream of the catalyst. The estimated ammonia storage amount is then used to control the amount of reductant injected into the catalyst to maintain desired ammonia storage amount such that maximum NOx conversion efficiency coupled with minimum ammonia slip are achieved.

In a method of controlling an exhaust gas system of an internal combustion engine including a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, the nitrogen oxide reducing catalyst and the nitrogen oxide sensor are disposed in the exhaust gas system operated mainly under a lean condition, respectively. An output value of the nitrogen oxide sensor is compared with a predetermined value, and an operation condition of the internal combustion engine is temporarily changed into a stoichiometric condition or a rich condition, or a fuel is injected upstream of the nitrogen oxide reducing catalyst, so that the nitrogen oxide adsorbed to the nitrogen oxide reducing catalyst is detached or decomposed, and again the internal combustion engine is operated under the lean condition. Deterioration of the catalyst is determined based on Nox amount which is calculated from the sensor output, exhaust has flow amount and vehicle running distance.

A method of determining the amount of particulate accumulated in a particulate filter, is based on determining possible variations in the spatial distribution and / or physical-chemical properties of the particulate as a function of engine operating conditions and past particulate accumulation in the particulate filter. A number of reference values defining a relationship between the amount of particulate accumulated in the particulate filter and the pressure drop across the particulate filter are mapped, each of the reference values relating to a respective steady engine operating condition in which particulate is accumulated in the particulate filter. In a given engine operating condition, an operating value of the parameter is then determined as a function of the reference value of the parameter relative to the same steady engine operating condition, and of past particulate accumulation in the particulate filter.

A system and method for regenerating particulate filters, catalyzed soot filters and NOx catalysts for a vehicle having a compression ignition engine. An engine control module controls engine operation and regeneration functions. The engine preferably includes an integrated starter / alternator / flywheel / retarder assembly. A load bank heater is provided in the exhaust system that is activated to directly heat exhaust gases raising the temperature thereof and approaching the temperatures required for regeneration and desulfation. Activation of the heater applies a load through the integrated starter / alternator / flywheel / retarder assembly that increases the load on the engine and in turn further increases the temperature of the exhaust to levels required for regeneration and desulfation.

A method and apparatus to reduce the emissions of an exhaust stream is provided. One feature of the present invention includes a control unit for metering a reagent into the exhaust stream. The control unit adjusts a quantity of the reagent to be metered into the exhaust stream. One embodiment of the present invention concerns a method of removing nitrogen oxides in exhaust gases from a diesel engine by introducing ammonia into the exhaust stream. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

A system for diagnosing the quality of a reagent solution may comprise a reagent solution source for supplying the reagent solution to an emissions catalyst of an internal combustion engine. Means may be provided for determining a quality value corresponding to the quality of the reagent solution. A first filter may receive the quality value and produce a first filtered quality value, and a first comparator may compare the filtered quality value to a threshold and produce a fault value if the first filtered quality value crosses the threshold. Alternatively or additionally, a second filter may receive the quality value and produce a second filtered quality value. A second comparator may compare a difference between the first and second filtered quality values to another threshold and produce another fault value if the difference crosses that threshold.

In one embodiment, a reductant system comprises: a high pressure reductant pump in operable communication with a power source, wherein the reductant pump comprises a reductant chamber and is capable of pressurizing reductant to a pressure of greater than or equal to 500 psi; a reductant reservoir in fluid communication with the reductant chamber; and an atomizer in fluid communication the reductant chamber. In another embodiment, the reductant system comprises: a reductant pump; system pump in operable communication the reductant pump, a reductant reservoir in fluid communication with the reductant chamber, and an atomizer in fluid communication the reductant chamber. The system pump is configured to provide motive power via a pressurized fluid to the reductant pump, and the system pump is fluidly isolated from a reductant chamber in the reductant pump.

An engine exhaust gas cleaning method and system, which can effectively reduce emission amounts of particular components, such as NOx, contained in exhaust gas by adding an additive, such as urea water or light oil, into an exhaust passage, which is adaptable for a reduction of the cleaning rate caused by deterioration of a catalyst, which can always maintain a high cleaning rate during acceleration and deceleration as well, and which can minimize environmental pollution with use of the additive in the least necessary amount. The engine exhaust gas cleaning system comprises a catalyst for removing a particular component, represented by NOx, contained in exhaust gas of an engine, an additive adding unit for adding, to the exhaust gas, an additive for reducing the particular component represented by NOx, and an EGR amount adjusting unit for adjusting an EGR amount. An addition amount of the additive and the EGR amount are set depending on an operating state and deterioration of the catalyst with time. The catalyst is regenerated when a cleaning capability of the catalyst has reduced to a predetermined value or below.

An emission control system has a catalyst and a sensor responding to a component of exhaust gas. In order to speed warming up the catalyst, the emission control system increases the amount of heat dissipated by exhaust gas. A diagnosis of the emission control system is carried out by determining whether the amount of heat dissipated by exhaust gas is sufficient or insufficient. The amount of heat dissipated by exhaust gas is represented by the length of time to an activated state of the sensor. In the diagnosis, the amount of heat generated by a heater provided in the sensor is taken into consideration. The diagnosis can also be carried out before and after the warming up the catalyst. The heater can also be deactivated. Detection of an abnormality of a secondary air control system can be based on a component of exhaust gas. If the amount of heat dissipated by exhaust gas is found insufficient, additional control can be executed. The amount of heat dissipated by exhaust gas can also be represented by an intake air volume and an air-fuel ratio.

In one embodiment, a system may include a gas turbine system. the gas turbine system includes a gas turbine, an after-treatment system that may receive exhaust gases from the gas turbine system, and a controller that may receive inputs and model operational behavior of an industrial plant based on the inputs. The industrial plant may include the gas turbine and the after-treatment system. The controller may also determine one or more operational parameter setpoints for the industrial plant, select the one or more operational parameter setpoints that reduce an output of a cost function, and apply the one or more operational parameter setpoints to control the industrial plant.

A diesel powered vehicle is provided with an SCR system which uses an external reducing reagent to convert NOx emissions in a manner which accounts for the effects of NOx transient emissions on the reducing catalyst. Actual NOx emissions produced by the engine are filtered using a variable NOx time constant in turn correlated to the reductant / NOx storage capacity of the reducing catalyst at its current temperature to account for changes in the SCR system attributed to NOx transient emissions. Catalyst temperature is filtered using a variable catalyst time constant corresponding to current space velocity of the exhaust gas to account for changes in the catalyst temperature attributed to NOx transient emissions. The reductant is metered on the basis of the filtered, corrected NOx concentration applied at a NSR ratio based, in turn, on the filtered, corrected reducing catalyst temperature.

A system for controlling the temperature of a particulate filter coupled to an exhaust outlet of an internal combustion engine includes a controller responsive to volumetric flow and temperature of exhaust gas to determine a filter regeneration parameter. In a hybrid electric-engine vehicle application, various control strategies are implemented as a function of the regeneration parameter to control exhaust gas temperature suitably for proper regeneration of the particulate filter. Such strategies include shifting the duty cycle of the engine toward lower engine speed operation along lines of constant power output, modifying the ratio of electrical power and engine power and controlling recharging of the battery supplying electrical energy to the vehicle's electric drive motor under vehicle deceleration conditions. In vehicle applications including a transmission coupled directly to the engine, shift points of the transmission are modified as a function of the regeneration parameter to control exhaust gas temperature.

A diesel particulate filter (14) which traps particulate matter and a NOx trap catalyst (13) which traps nitrogen oxides are installed in series in an exhaust passage (10) of a diesel engine (1). A controller (21) calculates a particulate matter deposition amount in the diesel particulate filter (14) (S4). The controller (21), when the particulate matter deposition amount exceeds a first predetermined amount (PM2), prevents sharp increase of the particulate matter deposition amount by prohibiting rich spike where the oxygen concentration of the exhaust gas is controlled to a value corresponding to a rich air-fuel ratio in order to regenerate the NOx trap catalyst (13) (S301, S302, S306), and prevents the particulate matter deposition amount of the diesel particulate filter (14) from reaching a limit.

The present invention provides methods and apparatus for injecting fluid, such as an aqueous urea solution, into an exhaust stream in order to reduce oxides of nitrogen (NOx) emissions from diesel engine exhaust The present invention uses mechanical spill return atomization techniques to produce droplets approximately 50 μm SMD (Sauter mean diameter) or smaller. This size range is appropriate to allow urea to react into ammonia within the residence time associated with an on-road diesel engine. This effect is achieved through the use of a whirl plate having a plurality of whirl slots surrounding an exit orifice of the injector, which produce a high velocity rotating flow in the whirl chamber. When the rotating flow of fluid is passed through the exit orifice into an exhaust stream, atomization occurs from a combination of centrifugal force and shearing of the fluid by air as it jets into the exhaust stream.

A method for operating an internal combustion engine (100) and exhaust system therefor includes the step of initiating a regeneration event in a diesel particulate filter (DPF 109) (401). A first oxygen concentration (213) of a gas upstream of the DPF 109, and a second oxygen concentration (215) of the gas downstream of the DPF 109 are sensed (403) to infer a rate of combustion of material in the DPF (405) based on the difference between the first (213) and the second (215) oxygen concentrations. The rate of combustion is compared to a threshold value (409) and the regeneration event in the DPF 109 is terminated (411) if the rate of combustion is above the threshold.

An upstream side catalyst and a downstream side catalyst are disposed in an exhaust passage. A first oxygen sensor is disposed between these two catalysts and a second oxygen sensor is disposed downstream of the downstream side catalyst. The air-fuel ratio is forcibly oscillated and the oxygen storage capacity of the upstream side catalyst is detected. Deterioration of the upstream side catalyst is then detected based on whether this oxygen storage capacity is larger than a predetermined value. The forced oscillation of the air-fuel ratio is performed only when the oxygen storage state of the downstream side catalyst is appropriate.

The invention provides a controller and cylinder deactivation system to regenerate an exhaust aftertreatment device for a multicylinder engine that operates primarily at an air / fuel ratio that is lean of stoichiometry. The invention uses the cylinder deactivation system to control temperature and air / fuel ratio of an exhaust gas feedstream going into an aftertreatment device. The invention also increases the amount of fuel delivered to each non-deactivated cylinder by an amount sufficient to maintain operating power of the engine. The regeneration action includes desorbing NOx from a NOx adsorber catalyst, desulfating the NOx adsorber catalyst, and purging a diesel particulate trap.

A method of dosing a reagent into an exhaust gas stream of an internal combustion engine having an SCR catalyst, the method comprising injecting reagent from a reagent tank into the exhaust gas stream at a position upstream of the SCR catalyst using a reagent injector in accordance with a first dosing schedule in order to remediate a predetermined proportion of NOx in the exhaust gas stream, the first dosing schedule being associated with a first range of engine operating conditions; and injecting reagent from the reagent tank into the exhaust gas stream at a position upstream of the SCR catalyst using a reagent injector in accordance with a second dosing schedule in order to enable heat transfer between the reagent injector and said injected reagent, the second dosing schedule being associated with a second range of engine operating conditions.Dosing in accordance with said first or said second dosing schedule is carried out in dependence on whether engine operating conditions lie within said first or said second range of engine operating conditions, and the proportion of NOx in the exhaust gas stream which is remediated by dosing using said second dosing schedule is less than said predetermined portion. A reagent dosing system is also provided for dosing a reagent into the exhaust gas stream of an internal combustion engine, comprising a reagent tank for storing a supply of reagent, an injector module comprising an atomising dispenser and a positive-displacement metering pump which draws reagent from the reagent tank and delivers it to the dispenser a supply line coupling the reagent tank to the injector module, and a dosing control unit operable to control the injector module to inject reagent into the exhaust gas stream. A priming pump is provided to urge reagent along the supply line toward the injector module under selected conditions.

A method is presented for estimating an amount of ammonia stored in a urea-based SCR catalyst based on a dynamic model of the catalyst. The model takes into account chemical and physical properties of the catalyst, such as catalyst volume, the number of available ammonia storage cites, adsorption and desorption dynamics, as well as poisoning, thermal aging, and different catalyst operating temperatures, and generates the estimate based on a measured or estimated amount of NOx in an exhaust gas mixture upstream of the catalyst, an amount of reductant injected into the catalyst to facilitate NOx reduction, and on a measured value of NOx in an exhaust gas mixture downstream of the catalyst. The estimated ammonia storage amount is then used to control the amount of reductant injected into the catalyst to maintain desired ammonia storage amount such that maximum NOx conversion efficiency coupled with minimum ammonia slip are achieved.

A fuel control system for a gas turbine engine that includes a primary fuel circuit, a fuel tuning circuit, a plurality of combustors connected to the fuel tuning circuit, oxygen and carbon dioxide sensors in the exhaust stream and a feedback control loop operatively connected to the fuel tuning circuit and to the oxygen and carbon monoxide sensors which serve to control the precise amount of fuel and air being fed to each one of the plurality of combustors in the engine. A parallel array of control valves in a tuning fuel circuit connect to corresponding ones of the plurality of combustors in the gas turbine engine. The fuel control system thereby “fine tunes” the amount of fuel and air being fed to each combustor using data regarding the detected oxygen and carbon monoxide concentrations in the exhaust gas as provided through a feedback control loop.

Method for activation of the regeneration of a particulate filter for a motor vehicle engine, comprising the steps of calculating an estimated value (xM) of a quantity of particulate accumulated in the particulate filter; comparing (8) the estimated value (xM) with a threshold value (mTH) corresponding to a predetermined maximum quantity of particulate; and activating the regeneration (9) if the estimated value (xM) exceeds the threshold value (mTH). The step of calculating an estimated value (xM) comprises the steps of estimating a first quantity of particulate (xMS) accumulated in the particulate filter by means of a statistical model (3) based on experimental data; estimating a second quantity of particulate (xMF) accumulated in the particulate filter by means of a physical model (2) using physical quantities measured; determining a field of admissibility on the basis of the first quantity of particulate (xMS); comparing the estimated value (xM) with the second quantity of particulate (xMF) if the second quantity of particulate (xMF) is within the field of admissibility; and limiting the estimated value (xM) if the second quantity of particulate (xMF) is outside the field of admissibility.

A control unit activates regeneration assist means, if a specific operating state involving incomplete combustion of particulates by NO2 continues for a predetermined period or more, as a first determination condition, and controls an exhaust gas temperature or a temperature of a catalyst to enhance the conversion efficiency of the catalyst into NO2, thereby continuously regenerating the particulates. The control unit activates forced regeneration means, if a deposited amount of particulates detected by deposited amount detecting means exceeds a predetermined value, as a second determination condition, and controls the exhaust gas temperature or a temperature of a filter to be higher than that of when the regeneration assist means is activated to forcibly regenerate the filter. The control unit activates either the forced regeneration means or the regeneration assist means in accordance with the temperature sensed by temperature sensing means, if the first and second determination conditions are simultaneously established.