Optimal Integrated Emission Management through Variable Engine Calibration

Ritzmann, Johannes; Chinellato, Oscar; Hütter, Ralf; Onder, Christopher H.

doi:10.3390/en14227606

Cited by 7 publications

(6 citation statements)

References 30 publications

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“…The inputs to be optimized are J rot Hd and J rot NO x . In [5], dynamic programming (DP) was used to solve the OCP, which is a reasonable choice of method when a global optimality guarantee is important and computational time is not limited. However, its use in an online model predictive controller is severely limited by the constraint on the maximal computation time that must be met to allow for feedback control.…”

Section: Real-time-capable Optimization Methodsmentioning

confidence: 99%

“…In this work, a reduced-order engine model resulting from a preoptimization of the engine operation was adopted from [5]. The benefit of the preoptimization is that the computational complexity of the subsequent online optimization is reduced.…”

Section: Engine Modelmentioning

confidence: 99%

“…The ATS model used in this work was adopted from [5]. The thermal model consists of a single lumped brick temperature ϑ, whose dynamics are…”

Section: Aftertreatment System Modelmentioning

confidence: 99%

“…In a previous publication by the authors, offline optimization was used to investigate this problem [5]. It was shown that, in order to achieve optimal performance, the fuel consumption, the engine-out NO x emissions, and the enthalpy provided to the ATS must be carefully managed during a mission.…”

Section: Introductionmentioning

confidence: 99%

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Model Predictive Supervisory Control for Integrated Emission Management of Diesel Engines

Ritzmann

Peterhans²,

Chinellato³

et al. 2022

Energies

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In this work, a predictive supervisory controller is presented that optimizes the interaction between a diesel engine and its aftertreatment system (ATS). The fuel consumption is minimized while respecting an upper bound on the emitted tailpipe NOx mass. This is achieved by optimally balancing the fuel consumption, the engine-out NOx emissions, and the ATS heating. The proposed predictive supervisory controller employs a two-layer model predictive control structure and solves the optimal control problem using a direct method. Through experimental validation, the resulting controller was shown to reduce the fuel consumption by 1.1% at equivalent tailpipe NOx emissions for the nonroad transient cycle when compared to the operation with a fixed engine calibration. Further, the controller’s robustness to different missions, initial ATS temperatures, NOx limits, and mispredictions was demonstrated.

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Section: Real-time-capable Optimization Methodsmentioning

confidence: 99%

Section: Engine Modelmentioning

confidence: 99%

“…The ATS model used in this work was adopted from [5]. The thermal model consists of a single lumped brick temperature ϑ, whose dynamics are…”

Section: Aftertreatment System Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Model Predictive Supervisory Control for Integrated Emission Management of Diesel Engines

Ritzmann

Peterhans²,

Chinellato³

et al. 2022

Energies

Self Cite

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“…Recent studies have proposed a framework to jointly optimize the engine and ATS for transient operation using a variable engine calibration. [13][14][15][16] This framework allows to operate the engine at the Pareto-optimal trade-off curves of efficiency, NOx emissions, and exhaust enthalpy. The latter quantity is used to ensure that the ATS is operated in the correct temperature window.…”

Section: Introductionmentioning

confidence: 99%

A method to quantify the advantages of a variable valve train for CI engines

Moretto,

Hänggi,

Omanovic

et al. 2023

International Journal of Engine Research

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Today’s CI engines are subject to strict regulations of pollutant emissions and ambitious fuel consumption targets. Therefore, the interaction between the engine and the exhaust aftertreatment system (ATS) has become increasingly important. Numerous studies have shown that a variable valve train (VVT) improves the interaction between engine and ATS. However, most of these studies either quantify the advantage on a specific engine or only present complex CFD models, such that the results are not easily transferable to different engines. Thus, engine manufacturers cannot directly use these results to assess the advantage of various VVT strategies for their engines. In this paper, we propose a cycle-discrete cylinder model based on first principles which allows to simulate various VVT strategies. In contrast to present methods based on CFD, the proposed cylinder model can be realized with the equations presented. Furthermore, the model is identified with measurement data of an engine without a VVT. A separate engine, which is retrofitted with a fully VVT, is used to validate the proposed modeling approach. Using the identified model in combination with a mean-value model of the air path, we are able to simulate the effects of early intake valve closing, early exhaust valve opening, and cylinder deactivation for a complete CI engine that has no VVT installed. The model is then used to highlight the advantage of a VVT for two scenarios at part-load operation. At cold start, where the temperature of the ATS must be increased quickly, variable valve timing achieves higher enthalpy flows to the ATS while also lowering engine-out NOx emissions when compared to a standard engine strategy. If the ATS is at the operating temperature, cylinder deactivation achieves significantly higher enthalpy flows which prevents the ATS from cooling down. In addition, cylinder deactivation also lowers fuel consumption and engine-out NOx emissions.

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