SCR Ammonia Dosing Control by a Nonlinear Model Predictive Controller

Stadlbauer, Stephan; Waschl, Harald; Re, Luigi del

doi:10.3182/20140824-6-za-1003.02497

Cited by 7 publications

(2 citation statements)

References 14 publications

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“…With the popularization of the application of nitrogen oxide sensors, the SCR control method has also transitioned from open-loop control to closed-loop control [13], and closed-loop control using a downstream nitrogen oxides signal has been applied in SCR systems [14]. Because the SCR system has a relatively large delay on the time scale [15] and the working scenario of the mobile machinery has changed, the direct use of a single PID closed-loop control will lead to the periodic oscillation of the system [16], and a new closed-loop control method must be adopted [17,18].…”

Section: Introductionmentioning

confidence: 99%

Research on Mobile Machinery NOx Emission Control Based on a Physical Model and Closed-Loop Control

Yue

Zhang

et al. 2022

Processes

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Mobile machinery means a power-driven vehicle that is specifically designed and constructed to perform work on or off the road. To reduce the nitrogen oxide (NOx) emissions that come from mobile machinery, a combination of a physical model and closed-loop control is applied to the selective catalytic reduction (SCR) system. Based on the design of the variable cross-section extended exhaust structure, the differential pressure measurement was achieved, and the physical model of the exhaust flow based on the differential pressure was established. Based on the analysis of the heat and mass transfer process of the SCR catalyst, a prediction model for the internal temperature field of the catalyst was established by combining the upstream and downstream exhaust temperature sensors. Using the SCR downstream nitrogen oxides signal and the proportional–integral–derivative (PID) closed-loop control algorithm, segmented PID closed-loop control under the large hysteresis response of the SCR system was realized. The above algorithms were used to form the control code through MATLAB/Simulink and downloaded to the embedded microprocessor. The test results show that the established model can realize the real-time calculation of the exhaust gas flow rate and the internal temperature of the catalyst. Under steady-state conditions, the calculation error of the exhaust flow rate is less than ±3%, and the calculation error of the catalyst temperature is less than ±5%. Under transient conditions, the calculation error of the exhaust flow rate is less than ±9%, and the calculation error of the catalyst temperature is less than ±8%. The nitrogen–oxygen signal-based PID closed-loop algorithm can improve the nitrogen–oxygen conversion efficiency and control accuracy of the model.

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Section: Introductionmentioning

confidence: 99%

Research on Mobile Machinery NOx Emission Control Based on a Physical Model and Closed-Loop Control

Yue

Zhang

et al. 2022

Processes

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“…Nakada et al 9 employed a reference governor for aftertreatment temperature control of a diesel engine to consider uncertainties in real-world control; its viability was experimentally shown in comparison to the case without a reference governor. Stadlbauer et al 10 developed a nonlinear model predictive controller to govern the ammonia-dosing of the SCR in a DOC-DPF-SCR aftertreatment system using a physics-based SCR model. Its viability was evaluated by simulation.…”

Section: Introductionmentioning

confidence: 99%

Model-based control of diesel engines with multiple fuel injections

Yamasaki

Ikemura

Kaneko

2017

International Journal of Engine Research

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We developed a feed-forward controller for a conventional diesel combustion engine with triple fuel injection and experimentally evaluated its performance. A combustion model that discretizes an engine cycle into a number of representative points to achieve a light calculation load is embedded into the controller; this model predicts the in-cylinder gas-pressure-peak timing with information about the operating condition obtained from the engine control unit. The controller calculates the optimal main-fuel-injection timing to control the in-cylinder gas-pressure peak using the prediction result as a controller with a single input and output. The controller's performance was evaluated by experiments using a four-cylinder diesel engine under changing the target value of the in-cylinder gas-pressure-peak timing during a target-following test and the performance was also evaluated under changing the exhaust gas recirculation ratio at the constant target value of the in-cylinder gas-pressure-peak timing for the disturbance-response test. It was found that the controller could calculate the optimal main-injection timing over a cycle and maintain the targeted in-cylinder gas-pressure-peak timing even when the target value or exhaust gas recirculation changed. The combustion model was also shown to be fast enough at predicting diesel combustion for onboard control.

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