Study on Development of a Urea-SCR System of Diesel Engine

2014 ◽  
Vol 541-542 ◽  
pp. 747-751
Author(s):  
Tao Qiu ◽  
Xu Chu Li ◽  
Jing Peng ◽  
Yan Lei ◽  
Guang Zhao Yue
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Stage Iv ◽  
Control Unit ◽  
Nox Emission ◽  
Scr System

Aimed at the diesel engine, a selective catalytic reduction (SCR) system was developed. In this system, the urea pump is integrated with a urea tank, air and urea mix in the injector, catalyst convertor is based on vanadium. Combining with a self-developed control unit, the urea-SCR system was tested on the engine bench. The ESC experiment results indicate that the NOx emission can be reduced effectively which meets the China stage IV regulation.

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.

Experimental Study on the Implementation of Emission Standards Euro V Diesel Engine

2015 ◽  
Vol 719-720 ◽  
pp. 243-248
Author(s):  
Li Jian Zhu ◽  
Yu Qun Wang
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Emission Standard ◽  
Test Analysis ◽  
Engine Exhaust ◽  
Emission Standards ◽  
Engine Emission ◽  
Scr System ◽  
Diesel Engine Emission

To make diesel engine Exhaust meet Euro V standard , the most efficient way was to use SCR(Selective Catalytic Reduction).In this paper ,the composition of the urea-SCR system, essential parts and technology of urea-SCR and the strategy to reduce NOx exhaust was analyzed carefully. And through the test analysis, Selective catalytic reduction technical could Euro V diesel engine emission standard had confirmed.

scholarly journals Solid Selective Catalytic Reduction: A Promising Approach towards Reduction of NOx Emission from Exhaust of CI Engines

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
M. K. Yadav ◽  
A. K. Srivastava
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Diesel Engines ◽  
Urban Areas ◽  
Catalytic Reduction ◽  
Nox Emission ◽  
Engine Exhaust ◽  
Diesel Engine Exhaust ◽  
Reduction Of Nox ◽  
Ci Engines

The rising rate of pollution in urban areas has become a worldwide concern in recent years. Diesel engines are considered one of the largest contributors to environmental pollution caused by exhaust emissions, and they are responsible for several health problems as well. Diesel engines contain carbon monoxide, carbon dioxide, unburned hydrocarbons, and oxides of nitrogen. The reduction of Nitric oxides (NOx) emission from diesel engine exhaust is currently being researched by automotive manufacturers. After much research, selective catalytic reduction (SCR) technology was discovered to be effective in reducing nitrogen oxide emission from diesel engine exhaust. This paper is an attempt to explore the problems associated with the use of selective catalytic reduction (SCR) and compares selective catalytic reduction (SCR) with the latest technology named solid selective catalytic reduction (SSCR) for efficient reduction of NOx emission from the exhaust of diesel engines. The issue of contamination, malfunctioning, and freezing of diesel exhaust fluid (DEF) at low temperatures are the major problems associated with the application of SCR. It is observed that by controlling the quantity of ammonia slip, SSCR can give better performance in the reduction of NOx emission from the exhaust of diesel engines.

Backstepping Based Nonlinear Ammonia Surface Coverage Ratio Control for Diesel Engine Selective Catalytic Reduction Systems

2009 ◽  
Author(s):  
Ming Feng Hsieh ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
System Dynamics ◽  
Selective Catalytic Reduction ◽  
Surface Coverage ◽  
Catalytic Reduction ◽  
Control Law ◽  
Ammonia Emissions ◽  
Coverage Ratio ◽  
Cycle Simulation ◽  
Scr System

This paper presents an ammonia surface coverage ratio control approach based on the backstepping concept for diesel engine selective catalytic reduction (SCR) systems. SCR models with multiple cells connected in cascade provide more accurate representations of the actual SCR system dynamics by considering the spatial distribution. Control of SCR system ammonia coverage ratio is critically important and effective in terms of ensuring low tailpipe NOx and ammonia emissions. However, such a task is also very challenging primarily due to the nonlinearities of the SCR dynamics and limited ammonia injection control authority. Grounded in the understanding of the SCR nonlinear dynamic characteristics, a backstepping-based nonlinear control law is then proposed to regulate the ammonia surface coverage ratio of the last SCR cell in order to tightly control the tailpipe NOx and ammonia emissions. Lyapunov-based analyses show the stability of the designed control law. FTP75 test cycle simulation results based on a full-vehicle (including engine, chassis, and aftertreatment systems) model illustrated that, compared with a conventional PID controller, the nonlinear backstepping control law can more appropriately handle the SCR system dynamics and exhibits superior ammonia coverage ratio control capability.

scholarly journals A study effects of injection pressure and wall temperature on the mixing process of NOx and NH3 in Selective Catalytic Reduction system

2020 ◽  
Vol 11 (1) ◽  
pp. 45
Author(s):  
Muhammad Khristamto Aditya Wardana ◽  
Ocktaeck Lim
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Wall Temperature ◽  
Public Transportation ◽  
Catalytic Reduction ◽  
Numerical Study ◽  
Mixing Process ◽  
Study Results ◽  
Scr System ◽  
The Impact

Diesel engines are commonly used for public transportation on-road and off-road applications. Growth production of the diesel engine is very significant from year to year. Nitride Oxide (NOx) from diesel engine was one of the major sources of air pollution. Selective Catalytic Reduction (SCR) has been successfully used to reduce NOx from a diesel engine with a chemical reaction from ammonia (NH3). The mixing reaction between NOx and NH3 reaction can produce steam (H2O) and Nitrogen (N2). However, ammonia uniformity pattern usually not homogenization and the ammonia was difficult to mix with NOx. The constant air flows incomplete to assist the spray injector to spread NH3 to all corners of SCR. The impact study of turbulent phenomena and standard k-epsilon Low-Reynolds Number model to the mixing process in the SCR system using STARCCM+. The simulation studies are conducted under different pressure (4 to 6 bars), the injection rate (0.04 g/s) and temperature (338 K – 553 K) and the high pressure and high velocity magnitude creating turbulent swirl flow. The ammonia decomposition process and mixing process with NOx were investigated using a box with optical access. The simulation and numerical study results validated using back pressure value and the distribution of NOx concentration value from the catalyst outlet. The wall temperature will increase the urea evaporation to generate ammonia and gas pressure will increase the mixing process and chemical process in the SCR system. These reactions enable to optimize the SCR system technology which eventually able to reduce the NOx quantity from a diesel engine.

A basic study on a urea-selective catalytic reduction system for a medium-duty diesel engine

2005 ◽  
Vol 6 (1) ◽  
pp. 11-19 ◽  
Author(s):  
J Kusaka ◽  
M Sueoka ◽  
K Takada ◽  
Y Ohga ◽  
T Nagasaki ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Direct Injection ◽  
Chemical Species ◽  
Operating Conditions ◽  
Basic Study ◽  
Catalyst Temperature ◽  
Scr System ◽  
Load Conditions

NOx conversion performance of a urea-selective catalytic reduction (SCR) system comprising V2O5/TiO2 catalyst under steady state operating conditions of an 8-litre, common-rail turbo direct injection (TDI) diesel engine was investigated. It was shown that the urea-SCR system achieves 70–90 per cent NOx conversion under medium and high load conditions at 1440 r/min and that NOx conversion is low under low load conditions because of the low catalyst temperatures and the NO/NO2 ratio being higher than unity. It was also shown that NOx conversion exceeds 90 per cent when the catalyst temperature is higher than 530 K. To investigate the details of the chemistry and thermofluid dynamics within the urea-SCR system, a computational fluid dynamics (CFD) code that incorporates detailed surface chemistry was developed based on the modified subroutines of CHEMKIN-II. The spatial variations of chemical species including NO and NH3 in a thin catalyst channel was calculated using the model. The calculated result of NO conversion showed relatively good agreement with experimental results.

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.

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