3D-Semi 1D Coupling for a Complete Simulation of an SCR System

Abidin, Zainal; Das, Kaushik; Roberts, Charles W.

doi:10.4271/2013-01-1575

Cited by 8 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2D models are approximations of 3D models, which are more commonly used for numerical simulations as are not as computationally intensive as 3D models. When the injector is closer to the front-face of the monolith, the ammonia concentration profile entering the monolith is nonuniform due to insufficient mixing time, which in turn reduces NO x conversion efficiency . Although NO x conversion can be improved by increasing the NH 3 /NO x ratio, this is at the cost of unreacted ammonia exiting the converter, which is undesirable.…”

Section: Introductionmentioning

confidence: 99%

“…When the injector is closer to the front-face of the monolith, the ammonia concentration profile entering the monolith is nonuniform due to insufficient mixing time, which in turn reduces NO x conversion efficiency. 14 Although NO x conversion can be improved by increasing the NH 3 /NO x ratio, this is at the cost of unreacted ammonia exiting the converter, which is undesirable. Moreover, it is known that insufficient residence time or urea deposition on the walls of the mixing chamber can cause incomplete conversion of urea.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling the Effect of Nonuniformities from Urea Injection on SCR Performance Using CFD

Dammalapati

Aghalayam

Kaisare

2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

A computational fluid dynamics model, consisting of a mixing chamber coupled with a catalytic converter, is developed for the selective catalytic reduction (SCR) of NO x using urea. The NH3 required for the SCR reactions is produced from the injection and decomposition of urea in the mixing chamber. The conversion efficiency and concentration distribution of NH3 from the mixing chamber are analyzed for a range of operating conditions. The flow and species distribution profiles from the mixing chamber are incorporated as inlet boundary conditions at the entrance of the downstream SCR convertor. The SCR convertor comprises a central catalytic monolith and inlet and outlet diffuser sections. Variations in NO x concentration were observed within the monolith due to heat losses and nonuniformities in ammonia concentrations. While heat effects under non-isothermal conditions slightly improved the NO x conversion efficiency, nonuniformities in ammonia concentrations did not significantly influence the SCR performance. Thus, the radial variations in NH3 concentrations, owing to nonuniformity at the outlet of the mixing chamber, did not considerably impact the overall performance of the SCR. The effects of temperature, NO:NO2 ratio, and inlet velocity were investigated.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modeling the Effect of Nonuniformities from Urea Injection on SCR Performance Using CFD

Dammalapati

Aghalayam

Kaisare

2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…The reduction of nitric oxides takes place through reactions where ammonia gets consumed and nitrogen and water are produced [6]. A wide range of different numerical models in terms of accuracy, capabilities and computational efficiency are available today in literature [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. They vary from simple distributed models [7][8][9][10][11][12][13][14] to one's based on computational fluid dynamics (CFD) methods [15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

“…It means that it is possibly to split the simulation procedure into the two stages. For the first one is strictly recommended to use 3D CFD simulations, but for catalytic converter processes due to it honeycomb structure possible to reduce model up to 1D case [21]. In this study, a 1D model of SCR converter model was described and the algorithm considered non uniform parameters on inlet surface to prediction of NOx emissions rate was suggested.…”

Section: Introductionmentioning

confidence: 99%

Development of the model for a diesel engine catalytic converter

2019

View full text Add to dashboard Cite

One of the key issues of the modern engine development is to comply with today’s stringent emission standards. It forces the manufacturers to enhance in-engine and after treatment emission reduction technologies continuously. The selective catalytic reduction (SCR) is still the most effective technique for nitrogen oxides removal from exhaust gases of vehicles with diesel engines. Numerical modelling is widely used for SCR systems development and assessment. In this paper, a simplified one-dimensional numerical model of diesel SCR catalyst, which was implemented in Matlab, is described. The algorithm for automatic mesh generation describing real cross-section geometry of the catalyst block and the calculation procedure allowing to take into account non-uniform distribution of the gas flow parameters at the catalyst inlet are presented. Model was validated by the experimental data available in the literature. Numerical simulations for the full-scale modern SCR catalyst were carried out. The effect of the gas velocity non-uniformity at the catalyst inlet on the overall NOx reduction efficiency was evaluated.

show abstract

“…Currently, the development of a diesel engine SCR system device is mainly based on simulations which are divided into two main categories: flow field simulations based on the flow state and chemical reaction simulations based on kinetics calculations. The flow field approach simulates the flow state of the exhaust gas in the exhaust pipe and helps not only to optimize a large number of design parameters of the SCR system, but also considerably shortens the turnaround time necessary to develop new products [5,6]. Considerable efforts have been made to model the SCR system using flow field simulations [7].…”

Section: Introductionmentioning

confidence: 99%

Simulation of the flow field and the chemical reaction coupling of selective catalytic reduction (SCR) system using an orthogonal experiment

Zhang

2019

PLoS ONE

View full text Add to dashboard Cite

It is difficult to simulate both the flow field and the chemical reaction using, respectively, the flow state and kinetics calculations and actually reflect the influence of the gas flow state on the chemical change in a selective catalytic reduction (SCR) system. In this study, the flow field and the chemical reaction were therefore coupled to simulate a full Cu-Zeolite SCR system and the boundary conditions of the simulation were set by a relevant diesel engine bench test which included the exhaust temperature, the mass flow, and the exhaust pressure. Then, the influence of the gas flow state on the NO x conversion efficiency was investigated. Specifically, an orthogonal experimental design was used to study the influence of the injection parameters (position, angle, and speed) on the NH 3 distribution by establishing the NH 3 uniformity coefficient γ at the SCR catalyst capture surface in the flow field simulation. Then, the velocity capture surface of the SCR catalyst front section was sliced into coupled data transfer interfaces to study the effects of exhaust temperature, ammonia to NO x ratio (ANR), and the NO 2 /NO x on the NO x conversion efficiency. This was used as guidelines to optimize the SCR system control strategy. The results showed that a 1150 mm injection position, a 45°injection angle, and a 23 m/s injection velocity provided the most uniform NH 3 distribution on the SCR catalyst capture surface. For constant injection parameters, the NO x conversion efficiency was the highest when the exhaust temperature was 200°C—400°C, the ANR was 1.1, and NO 2 /NO x was 0.5.

show abstract

3D-Semi 1D Coupling for a Complete Simulation of an SCR System

Cited by 8 publications

References 8 publications

Modeling the Effect of Nonuniformities from Urea Injection on SCR Performance Using CFD

Modeling the Effect of Nonuniformities from Urea Injection on SCR Performance Using CFD

Development of the model for a diesel engine catalytic converter

Simulation of the flow field and the chemical reaction coupling of selective catalytic reduction (SCR) system using an orthogonal experiment

Contact Info

Product

Resources

About