Ammonia injection optimization for selective catalytic reduction aftertreatment systems

Plá, Benjamín; Bares, Pau; Sanchis, Enrique José; Aronis, André

doi:10.1177/1468087420933125

Cited by 13 publications

(10 citation statements)

References 50 publications

(47 reference statements)

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“…Today's engines are not in the list of engines to be admitted in the near future. Therefore, to comply with the exhaust emissions limits defined by the European Union (EU), engine manufacturers have approached the situation in two different ways: treating the pollution emission generated during combustion [4][5][6][7][8], which can have some problems, such as urea injection failures which is treated in [9], and trying to reduce these emissions via hybridization and increasing the combustion thermal efficiency. Increased thermal efficiency can be achieved by supercharging [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Numerical Evaluation in a Scaled Rotor-Less Nozzle Vaned Radial Turbine Model under Variable Geometry Conditions

et al. 2022

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The widespread trend of pursuing higher efficiencies in radial turbochargers led to the prompting of this work. A 3D-printed model of the static parts of a radial variable geometry turbine, the vaned nozzle, and the volute, was developed. This model was up-scaled from the actual reference turbine to place sensors and characterize the flow around the nozzle vanes, including the tip gap. In this study, a computational model of the scaled-up turbine was carried out to verify the results in two ways. For this model, firstly compared with an already validated CFD turbine model of the real device (which includes a rotor), its operating range was extended to different nozzle positions, and we checked the issues with rotor–stator interactions as well as the influence of elements such as the screws of the turbine stator. After showing results for different nozzle openings, another purpose of the study was to check the effect of varying the clearance over the tip of the stator vanes on the tip leakage flow since the 3D-printed model has variable gap height configurations.

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Section: Introductionmentioning

confidence: 99%

Numerical Evaluation in a Scaled Rotor-Less Nozzle Vaned Radial Turbine Model under Variable Geometry Conditions

et al. 2022

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“…Wassen et al 28 proposed a holistic engine model and exhaust aftertreatment model system, both based on model predictive control (MPC), in order to reduce the brake specific fuel consumption (BSFC). Pla et al 29 used optimal control tools to find the ideal urea injection profile for different N O x slip limits in a WLTC cycle. As a result, in the case that minimises N O x emissions while maintaining the same total amount of urea injected during the cycle, the reduction in N O x slip was 14.1%, and in the case where was maintained the same total amount of N O x slip for the lowest total amount of urea injected, the reduction in urea consumption was 33.5%.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous NOx and NH3 slip prediction in a SCR catalyst under real driving conditions including potential urea injection failures

Plá

Piqueras

Bares

et al. 2021

International Journal of Engine Research

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To reach the emission limits imposed by governments and reduce the negative impact on the environment, the use of aftertreatment systems has become essential for internal combustion engine (ICE) based powertrains. In particular, the selective catalytic reduction (SCR) system is a widespread aftertreatment technology with high efficiency for [Formula: see text] abatement which shows complex dynamics and requires urea injection as reducing agent. Current urea injection strategies usually rely on the [Formula: see text] emissions feedback. This work presents a model for the on-line simultaneous prediction of [Formula: see text] and [Formula: see text] emissions after the SCR catalyst, allowing the emissions estimation even in conditions of urea injector failure, when it is not possible to rely on the injector feedback signal. The proposed model is based on state of the art on-board after-treatment instrumentation and proposes an extended Kalman filter (EKF) to combine a data-based model and the analysis of sensor signals to provide a reliable estimation of [Formula: see text] and [Formula: see text] slip. The proposed strategy is experimentally assessed in dynamic driving cycles, such as Worldwide harmonised Light vehicles Test Cycle (WLTC) and Standardised Random Test (RTS). The proposed method is evaluated in standard conditions (without failures) and with urea injection failures of 25% and 120% of the nominal injection amount. As a result, the prediction on [Formula: see text] and [Formula: see text] slip has been improved in all injection failure conditions, by an overall average of 47.8% and 61.8%, respectively, when compared to state-of-the-art control oriented models (physically based zero dimensional model or data-based).

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“…Alongside to the LTC strategies, NOx emissions can also be reduced in the exhaust tail pipe thanks to after-treatment systems such as lean NOx traps (LNT) and selective catalytic reduction (SCR) [10,11]. Their efficient operation relies on a proper diagnostic which includes lambda (λ) and NOx measurement and models [12,13]. NOx sensors are getting higher attention and are being installed more often in commercial applications.…”

Section: Introductionmentioning

confidence: 99%

On-Line Optimization of Dual-Fuel Combustion Operation by Extremum Seeking Techniques

Plá

Bares

Barbier

et al. 2021

SAE Technical Paper Series

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Dual-fuel combustion engines have shown the potential to extend the operating range of Homogeneous Charge Compression Ignition (HCCI) by using several combustion modes, e.g. Reactivity Controlled Compression Ignition (RCCI) at low/medium load, and Partially Premixed Compression Ignition (PCCI) at high load. In order to optimize the combustion mode operation, the respective sensitivity to the control inputs must be addressed. To this end, in this work the extremum seeking algorithm has been investigated. By definition, this technique allows to detect the control input authority over the system by perturbing its value by a known periodic signal. By analyzing the system response and calculating its gradient, the control input can be adjusted to reach optimal operation. This method has been applied to a dual-fuel engine under fully, highly and partially premixed conditions where the feedback information was provided by incylinder pressure and NOx sensors. The gasoline fraction and the injection timing were selected as control inputs and an extremum seeking controller was designed and verified to optimize brake efficiency by tracking the ideal combustion phasing and to reduce NOx emissions as well.

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Ammonia injection optimization for selective catalytic reduction aftertreatment systems

Cited by 13 publications

References 50 publications

Numerical Evaluation in a Scaled Rotor-Less Nozzle Vaned Radial Turbine Model under Variable Geometry Conditions

Numerical Evaluation in a Scaled Rotor-Less Nozzle Vaned Radial Turbine Model under Variable Geometry Conditions

Simultaneous NOx and NH3 slip prediction in a SCR catalyst under real driving conditions including potential urea injection failures

On-Line Optimization of Dual-Fuel Combustion Operation by Extremum Seeking Techniques

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