Design of Urea-SCR Model of a Feedforward Controller Based on Simulation in Diesel Engine

2012 ◽  
Vol 562-564 ◽  
pp. 1924-1927
Author(s):  
Bao Yi Wang ◽  
Qian Wang
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Accurate Performance ◽  
Feedforward Controller ◽  
Simulation Results ◽  
Scr Model

Using a mathematical model, a feedforward controller model of Urea-SCR (selective catalytic reduction, SCR) in diesel engine is realized. At steady-state conditions, the simulated NOX concentration shows great consistence with the experimental value in the downstream of the converter. It can be seen that the simulation results show comparatively accurate performance of the model with the converter temperature changing linearly in the range from 450K to 750K.

Estimation of Ammonia Storage Nonuniformity for Urea-Based Selective Catalytic Reduction Systems

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Qinghua Lin ◽  
Pingen Chen
Keyword(s):  
Selective Catalytic Reduction ◽  
Emission Reduction ◽  
Catalytic Reduction ◽  
Urea Solution ◽  
Coverage Ratio ◽  
Ammonia Storage ◽  
Simulation Results ◽  
Parallel Configuration ◽  
Scr Model ◽  
The Impact

Ammonia storage nonuniformity has a significant impact on the emission reduction performance of urea-based selective catalytic reduction (SCR) systems. In this paper, a unique SCR platform with two catalysts in a parallel configuration was created for investigating the impact of ammonia storage nonuniformity on the emission reduction performance in a simulation environment. The established two-cell SCR platform allows users to independently control the ammonia-to-NOx ratio (ANR) for each catalyst using two independent urea solution injectors. Simulation results over US06 cycle demonstrate that, compared to the case without ammonia storage nonuniformity, the tailpipe NOx and ammonia emissions can be increased by 6.73% and 22.0%, respectively, due to the nonuniform ammonia storage in the case of an ANR nonuniformity index (NUI) at 0.2. Furthermore, an innovative model-based method was proposed for estimating the ammonia coverage ratio nonuniformity (i.e., ammonia storage nonuniformity if storage capacity is known) by utilizing a control-oriented SCR model and the tailpipe NOx and ammonia measurements at the confluence point. Simulation results proved the effectiveness of the proposed method in estimating the ammonia coverage ratio nonuniformity.

Comparative analysis on the effects of diesel particulate filter and selective catalytic reduction systems on a wide spectrum of chemical species emissions

2018 ◽  
Author(s):  
Z. Gerald Liu ◽  
Devin R. Berg ◽  
Thaddeus A. Swor ◽  
James J. Schauer‡
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Diesel Particulate Filter ◽  
Catalytic Reduction ◽  
Wide Spectrum ◽  
Chemical Species ◽  
Pollutant Emissions ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Aftertreatment Systems

Two methods, diesel particulate filter (DPF) and selective catalytic reduction (SCR) systems, for controlling diesel emissions have become widely used, either independently or together, for meeting increasingly stringent emissions regulations world-wide. Each of these systems is designed for the reduction of primary pollutant emissions including particulate matter (PM) for the DPF and nitrogen oxides (NOx) for the SCR. However, there have been growing concerns regarding the secondary reactions that these aftertreatment systems may promote involving unregulated species emissions. This study was performed to gain an understanding of the effects that these aftertreatment systems may have on the emission levels of a wide spectrum of chemical species found in diesel engine exhaust. Samples were extracted using a source dilution sampling system designed to collect exhaust samples representative of real-world emissions. Testing was conducted on a heavy-duty diesel engine with no aftertreatment devices to establish a baseline measurement and also on the same engine equipped first with a DPF system and then a SCR system. Each of the samples was analyzed for a wide variety of chemical species, including elemental and organic carbon, metals, ions, n-alkanes, aldehydes, and polycyclic aromatic hydrocarbons, in addition to the primary pollutants, due to the potential risks they pose to the environment and public health. The results show that the DPF and SCR systems were capable of substantially reducing PM and NOx emissions, respectively. Further, each of the systems significantly reduced the emission levels of the unregulated chemical species, while the notable formation of new chemical species was not observed. It is expected that a combination of the two systems in some future engine applications would reduce both primary and secondary emissions significantly.

scholarly journals Reduction of NOx Emission of a Diesel Engine with a Multiple Injection Pump by SCR Catalytic Converter

2016 ◽  
Vol 64 (4) ◽  
pp. 1205-1210 ◽  
Author(s):  
Vít Marek ◽  
Lukáš Tunka ◽  
Adam Polcar ◽  
Dušan Slimařík
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Catalytic Converter ◽  
Nox Emission ◽  
Multiple Injection ◽  
Scr Catalyst ◽  
Exhaust Gases ◽  
Injection Pump ◽  
Reduction Of Nox

This paper deals with reduction of NOx-emission of a diesel engine with multiple injection pump by SCR catalytic converter. Main aim of the measurement was the detection of SCR catalyst converter efficiency. Tests were realized at the Research and Development workplace of Zetor Tractor a.s. Used engine was equipped with a multiple injection pump with electromagnetic regulator of a fuel charge. During the experiment selective catalytic reduction and diesel particulate filter were used as an after treatment of harmful pollutants reduction. Testing cycle of the eight-point test was chosen and Non-Road Steady Cycle (NRSC) was maintained according to 97/68/EC directive. Results confirmed the dependencies between temperatures of SCR catalyst and exhaust gases and the volume of exhaust gases on efficiency of SCR catalyst. During the operation load of the engine, selective catalytic reduction reached efficiency over 90 %. Used after treatment system is suitable for reduction of harmful pollutants according to the Tier 4f norm.

Selective Catalytic Reduction of NO with Hydrocarbons:  Experimental and Simulation Results

1996 ◽  
Vol 35 (8) ◽  
pp. 2508-2515 ◽  
Author(s):  
Gesthimani D. Lionta ◽  
Sophia C. Christoforou ◽  
Evangelos A. Efthimiadis ◽  
Iacovos A. Vasalos
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Reduction Of No ◽  
Simulation Results

Perspective on SCR NOx control for diesel vehicles

2019 ◽  
Vol 4 (6) ◽  
pp. 969-974 ◽  
Author(s):  
Christine K. Lambert
Keyword(s):  
Steady State ◽  
Selective Catalytic Reduction ◽  
Research Design ◽  
Catalytic Reduction ◽  
System Research ◽  
Reduction Of No ◽  
Diesel Vehicles ◽  
Aqueous Urea ◽  
Nox Control ◽  
Scr System

The selective catalytic reduction of NOx with aqueous urea (“urea SCR”) is originally a steady-state technology that has been successfully applied to diesel vehicles worldwide. This Perspective summarizes 20+ years of SCR system research, design, and future improvements.

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