Predictive Modeling of Impact of ANR Non-Uniformity on Transient SCR System DeNOx Performance

Kalyankar, Apoorv; Munnannur, Achuth; Liu, Z. Gerald

doi:10.4271/2015-01-1055

Cited by 7 publications

(4 citation statements)

References 9 publications

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“…They found that the ANR uniformity is of great significance for NO x conversion. The transient de-NO x efficiency increased with increase in the weighted uniformity index, which was proposed in this work as being more representative of a transient cycle (Kalyankar et al, 2015). Lin and Chen (2019) established a new SCR platform and con-ducted simulations with it to investigate the impact of ammonia storage nonuniformity on SCR performance.…”

Section: Introductionmentioning

confidence: 97%

“…The ammonia storage at different axial locations of the SCR system can be predicted using their proposed model, which is of great value for control applications (Song et al, 2013). Kalyankar et al (2015) developed two predictive modeling approaches to assess the effect of ANR nonuniformity on the SCR + ammonia slip catalyst performance. They found that the ANR uniformity is of great significance for NO x conversion.…”

Section: Introductionmentioning

confidence: 99%

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Simulation Study of Ammonia Storage Characteristics of Selective Catalytic Reduction for Diesel Engines

Tan

Huang

et al. 2021

Environmental Engineering Science

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Non-road machinery is very important, but non-road machinery has problems such as working under complex operating conditions. Agricultural machinery is an important type of non-road machinery, which mainly relies on diesel engines due to their high fuel efficiencies. The exhaust temperature of agricultural machinery changes drastically under different working conditions. This article aims to research on pollution control of non-road machinery. Among the exhaust after treatment technologies, selective catalytic reduction (SCR) technology is a very important method to reduce NO x. In this study, a series of tests was conducted to investigate the effects of temperature and exhaust gas mass flow on the NO x conversion and dynamic ammonia storage space distribution characteristics in simulation models. The genetic algorithm, a kind of global optimization algorithm that can avoid local optimization, was used in the parameter identification process. The simulation results showed that the ammonia storage capacity of SCR catalyst decreases as the temperature of SCR increases. With the decrease in temperature, the NH 3 desorption rate gradually decreased. An uneven distribution of ammonia storage similar to the shape of e was observed in the simulation and this kind of uneven distribution is obvious at low temperature. The effective area of the catalyst is near the inlet of the catalyst. This work presents an approach to help figure out the details in the ammonia storage process. This work provides information about the dynamic ammonia storage characteristics and guide for better SCR design.

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Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Simulation Study of Ammonia Storage Characteristics of Selective Catalytic Reduction for Diesel Engines

Tan

Huang

et al. 2021

Environmental Engineering Science

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“…In this technology, typically the eutectic urea–water solution (UWS) is injected in the exhaust stream, which undergoes evaporation, thermolysis, and hydrolysis reactions to generate gaseous ammonia. , Ammonia then reduces NO x to nontoxic compounds over a vanadia- or zeolite-based catalytic substrate placed downstream of UWS injection location. As the worldwide NO x emission regulations have become more stringent, it is critical to deliver a uniform distribution of ammonia to the catalyst to minimize tailpipe NO x and ammonia slip. − Static mixers play a key role in achieving the desired ammonia uniformity by promoting decomposition on their hot surfaces and creating highly turbulent flow in the mixing section. However, the recent push toward the development of compact urea mixers to meet stringent space-claim requirements makes the impingement of UWS spray on the mixer walls unavoidable.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Investigation of Ammonia Uniformity in a Compact Selective Catalytic Reduction System

Kalyankar

Backhaus

Munnannur

et al. 2022

Ind. Eng. Chem. Res.

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Spray simulations based on a Eulerian−Lagrangian framework were conducted to predict ammonia uniformity in a urea-based compact selective catalytic reduction (SCR) system and validated against laser absorption tomography measurements at various operating points. Since ammonia distribution profile at the SCR inlet can change over time due to the transient nature of spray-induced wall cooling, changes in spray-wall interaction regime and wallfilm transport, simulations were conducted for a sufficiently long time to achieve quasi-steady temperature and wallfilm distribution profiles on the mixer walls. Simulation runtime was reduced using a database approach and frozen field approximation. Subsequently, one final spray injection cycle was simulated to obtain quasi-steady ammonia distribution at the SCR inlet. Prediction of ammonia rich and lean zones and uniformity index using this approach showed excellent correlation against measured data at various operating points and mixer designs.

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“…Kalyankar et al proposed a transient weighted uniformity coefficient. When the weighted uniformity coefficient increases, the NO x conversion efficiency increases . An-dong et al and Jing et al used Fire software to establish and verify the model of an SCR catalyst. , Through calculation and analysis, the effects of temperature, space velocity, ammonia nitrogen ratio, and NO/NO 2 molar ratio on the molar fraction field in the SCR catalyst were studied.…”

Section: Introductionmentioning

confidence: 99%

Experimental Research on Distribution Characteristics of NO_x Conversion Efficiency of a Diesel Engine SCR Catalyst

Wang

Li³

et al. 2021

ACS Omega

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An experimental investigation of the distribution characteristics of NO x conversion efficiency inside a selective catalytic reduction system is presented in this paper. Wash-coated and extruded vanadium-based selective catalytic reduction catalysts were investigated under an ANR (ammonia nitrogen ratio) of 1.0 and various exhaust gas temperature and flow rate conditions. A moveable sampling probe was located at various measuring points on the exit cross section of the selective catalytic reduction catalyst shell, and the final distribution maps of NO x conversion efficiency were obtained by the interpolation of measured data. The experimental result showed that the distribution of NO x conversion efficiency of the wash-coated selective catalytic reduction catalyst at the exit cross section was extremely nonuniform and the efficiency of the extruded SCR catalyst was uniform with a higher distribution at the center. A comparison experiment with 180° rotation of the selective catalytic reduction catalysts was implemented, and the efficiency distribution map of the wash-coated selective catalytic reduction catalyst also rotated 180° but that of the extruded selective catalytic reduction catalyst remained unchanged. The uniformity coefficient of the extruded selective catalytic reduction catalyst was higher than that of the wash-coated selective catalytic reduction catalyst used in this study.

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Predictive Modeling of Impact of ANR Non-Uniformity on Transient SCR System DeNOx Performance

Cited by 7 publications

References 9 publications

Simulation Study of Ammonia Storage Characteristics of Selective Catalytic Reduction for Diesel Engines

Simulation Study of Ammonia Storage Characteristics of Selective Catalytic Reduction for Diesel Engines

Numerical and Experimental Investigation of Ammonia Uniformity in a Compact Selective Catalytic Reduction System

Experimental Research on Distribution Characteristics of NO_x Conversion Efficiency of a Diesel Engine SCR Catalyst

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Predictive Modeling of Impact of ANR Non-Uniformity on Transient SCR System DeNOx Performance

Cited by 7 publications

References 9 publications

Simulation Study of Ammonia Storage Characteristics of Selective Catalytic Reduction for Diesel Engines

Simulation Study of Ammonia Storage Characteristics of Selective Catalytic Reduction for Diesel Engines

Numerical and Experimental Investigation of Ammonia Uniformity in a Compact Selective Catalytic Reduction System

Experimental Research on Distribution Characteristics of NOx Conversion Efficiency of a Diesel Engine SCR Catalyst

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Experimental Research on Distribution Characteristics of NO_x Conversion Efficiency of a Diesel Engine SCR Catalyst