Numerical analysis of NOx reduction for compact design in marine urea-SCR system

Choi, Cheolyong; Sung, Youl-Moon; Choi, Gyung‐Min; Kim, Duck Jool

doi:10.1515/ijnaoe-2015-0071

Cited by 40 publications

(14 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The UWS sprayed into the exhaust gas is converted to water and urea through evaporation in the first step. The reaction may also be in the liquid or molten phase as expressed in the following equation [21].…”

Section: Governing Equationsmentioning

confidence: 99%

The Effect of Exhaust Temperature on Urea-Water Decomposition in Marine SCR Systems

Bayramoğlu

Özmen²,

Cerit³

2019

International Journal of Computational and Experimental Science and Engineering

View full text Add to dashboard Cite

Reduction of nitrogen oxide (NOx) emissions from ships due to environmental pollution and greenhouse gas impact has been made obligatory by regulations introduced by the International Maritime Organization (IMO). Basically, NOx emission control mechanisms are divided into primary methods and aftertreatment methods. After-treatment methods focus on reducing NOx emissions from the exhaust gas by various methods. In this study, the efficiency of the urea transformation for different exhaust temperature values for a modelled Selective Catalytic Reduction (SCR) system has been investigated numerically. As a result of numerical model, isocyanic acid, temperature, urea and ammonia values have been determined for Urea-Water Solutions (UWS) process values. The study has been calculated by the computational fluid dynamics (CFD). The numerical results obtained were confirmed by experimental studies from the literature.

show abstract

Section: Governing Equationsmentioning

confidence: 99%

The Effect of Exhaust Temperature on Urea-Water Decomposition in Marine SCR Systems

Bayramoğlu

Özmen²,

Cerit³

2019

International Journal of Computational and Experimental Science and Engineering

View full text Add to dashboard Cite

show abstract

“…NOx is usually composed of NO more than 90%. Therefore, the reaction of SCR with ammonia of urea is as follows [16][17][18]…”

Section: Scr Reactions With Urea 40% Solutionmentioning

confidence: 99%

“…Equation 2is much faster and equation 3is slower than equation (1). [16][17][18] Table 4 shows the main urea-SCR reactions. According to Fang and DaCosta, 19 all reactions can be categorized as desirable and undesirable reactions, as well as undesirable degradation.…”

Section: Scr Reactions With Urea 40% Solutionmentioning

confidence: 99%

Installation and characteristics of urea-selective catalytic reduction systems for nitrogen oxide reduction in marine diesel engine

Ryu

Kim

Cho³

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part M:

View full text Add to dashboard Cite

Since 1 January 2016, the International Maritime Organization Tier III regulations concerning nitrogen oxides took effect. International Maritime Organization Tier III targets new ships weighing over 400 ton engaged in international sailing, especially those entering and leaving emission control areas. The number of emission control areas, including sulfur emission control areas, is forecasted to increase in Japanese seas and elsewhere; thus, all new ships intended for international sailing purposes must consider appropriate responses to these regulations. Currently, urea-selective catalytic reduction systems are frequently used to satisfy International Maritime Organization Tier III regulations in marine diesel engines, but these decrease ship engine performance due to increased engine exhaust gas pressure. Thus, following a study by Ryu et al., this research compares engine exhaust gas pressures at different engine loads (25%, 30%, 35%, 40%, 45%, and 50%) with the application of a thinner metal catalyst to a selective catalytic reduction reactor; metal catalyst thickness was reduced by 30% or more from the original sheet thickness of 0.1 t. Furthermore, 40% urea was injected into the exhaust gas line to conduct a comparative analysis of nitrogen oxide reduction. By changing the metal catalyst's sheet thickness, nitrogen oxide was reduced by more than 80%, while the engine exhaust gas pressure was lowered by approximately 13%-28%.

show abstract

“…Zhang et al designed a new claw mixer based on the traditional mixer and found that the new mixer can effectively reduce the risk of crystallization while ensuring a higher distribution of reducing agents [3]. Choi et al applied a numerical analysis of NOx reduction for compact design in marine urea-SCR system and found that the compact structure can reduce 55% of the chamber and connecting pipe without decreases of NOx reduction efficiency [4]. In addition, many researched have studied the miniaturization of the mixer of the SCR system [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Application Study on a New Hybrid Canning Structure of After-Treatment System for Diesel Engine

et al. 2020

View full text Add to dashboard Cite

Based on the airflow rotation concept, a new packaging structure was designed to meet the performance requirements of China-VI stage emission regulations. The new structure is a hybrid structure of spiral space with small blades and conical plates. The Computational Fluid Dynamics (CFD) simulation was used to analyze the velocity uniformity and ammonia uniformity of the flow field, and the results showed that velocity uniformity and ammonia uniformity were higher than 0.95, and the possibility of crystallization risk was very low. The actual performance of the new structural prototype was verified by means of engine bench testing. The test results were excellent and the conversion efficiency reached 0.96. The new selective catalytic reduction (SCR) urea mixed structure design greatly improved the conversion efficiency of the after-treatment system and has excellent anti-crystallization performance.

show abstract

Numerical analysis of NOx reduction for compact design in marine urea-SCR system

Cited by 40 publications

References 12 publications

The Effect of Exhaust Temperature on Urea-Water Decomposition in Marine SCR Systems

The Effect of Exhaust Temperature on Urea-Water Decomposition in Marine SCR Systems

Installation and characteristics of urea-selective catalytic reduction systems for nitrogen oxide reduction in marine diesel engine

Application Study on a New Hybrid Canning Structure of After-Treatment System for Diesel Engine

Contact Info

Product

Resources

About