The Benefits of Diesel Exhaust Fluid (DEF) Additivation on Urea-Derived Deposits Formation in a Close-Coupled Diesel SCR on Filter Exhaust Line

Lecompte, Matthieu; Obiols, Jerome; Cherel, J.; Raux, S.

doi:10.4271/2017-01-2370

Cited by 6 publications

(4 citation statements)

References 21 publications

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“…These systems combine Diesel diesel oxidation catalysts (DOC), UWS dosing and mixing devices, and selective catalytic reduction coated on particulate filters (SCRoF). However, a reduction in size causes shortening of the UWS droplets' flow paths and residence time, which adversely affects ammonia generation [3,15,17]. Efficiency of an SCR is highly dependent on the uniformity of the ammonia distribution at the inlet to the catalyst [10,21].…”

Section: Introductionmentioning

confidence: 99%

“…Nonetheless, such this improvement was advantageous to a certain extent. Lecompte et al [17] presented the a multistage experiment, where the impact of additives in a UWS on deposit formation and ammonia generation was evaluated in a closecoupled system from a passenger car. Relatively low gas mass flow rate and gas temperature caused an increase in the mass of the solid deposits.…”

Section: Introductionmentioning

confidence: 99%

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A conceptual design and numerical analysis of the mixerless urea-SCR system

Kaźmierski¹,

Górka²,

Kapusta³

2021

Combustion Engines

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In the present study, an innovative design of the urea-selective catalytic reduction (SCR) system without conventional mixing elements was developed. The aim was to obtain a high degree of urea decomposition, and uniform ammonia distribution at the inlet to the catalyst, while minimising the liquid film deposition and keeping the compact design. The concept of the design was based on creating high turbulences and elongating the flow paths of the droplets. The design was verified through a series of numerical simulations based on the Reynolds-averaged Navier–Stokes (RANS) approach and a discrete droplet model (DDM) spray representation. The analysis included various operating conditions as well as subcooled and superheated sprays. A uniform ammonia distribution was achieved regardless of the operating points and spray properties. Additionally, in the case of the flash-boiling injection, a further reduction of the wall film was observed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A conceptual design and numerical analysis of the mixerless urea-SCR system

Kaźmierski¹,

Górka²,

Kapusta³

2021

Combustion Engines

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“…Sadashiva et al studied the model to benefit dosage strategy at low temperature for SCR system [11]. Wang and Lecompte et al researched specific catalyst performance by ice melting method under the low temperature SCR [12][13]. Zhao et al introduced a solution to reduce deposit of SCR system at low temperature [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

A CAN-Based Urea Line Heater Diagnostics Development and Experimental Validation for Selective Catalytic Reduction (SCR) System

2021

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Urea line heating system is critical for Selective Catalytic Reduction (SCR) aftertreatment system under low temperature environment. Traditionally, the Electronic Control Unit (ECU) motivates urea lines heating command and diagnostics directly. This paper illustrates a Controller Area Network (CAN)-based line heater architecture development for the SCR aftertreatment system, as well as the diagnostics generation. The CAN-based line heater diagnostics is validated on vehicle experimental with four different given cases. It can be seen from the validation results that the diagnostics logic and algorithm are reasonable, and the line heater failure modes could be detected correctly including open circuit, short circuit and inducement. In addition, the failure modes are able to set or clear for each of the urea lines according to the diagnostics logic. ECU and ECU1 could communicate well between each other by CAN. This study introduces a new line heater architecture for SCR aftertreatment system which is meaningful for the whole vehicle assembly, which could be considered in the real application in future.

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“…Wang et al 16 investigated hydrothermal aging effects on the reduction of ammonia adsorption capacity over a commercial Cu-zeolite selective catalytic reduction catalyst under actual engine exhaust conditions. Additives were adopted by Lecompte et al 17 to reduce crystallisation at low temperatures or in urban traffic conditions. Wei et al 18 described procedures for processing the transient emission data measured at vehicle test sites to analyse and understand the performance of exhaust system after-treatment components.…”

Section: Introductionmentioning

confidence: 99%

Optimisation design of short pitch spiral hybrid SCR structure for improving the exhaust performance

Zhang

Hou

Lü³

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part D:

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As exhaust emission standards become increasingly stringent, the requirements for diesel exhaust post-treatment systems become increasingly demanding. This research focuses on the optimisation of a new hybrid structure to improve the performance of exhaust post-treatment systems. First, a short pitch spiral mixing chamber with sufficient mixing space and low temperature loss was designed to improve the evaporation of liquid droplets. Additionally, a conical plate mixer was used to conduct secondary mixing of the gas to improve the flow characteristics further. The ammonia uniformity and crystallisation risk of the new hybrid structure were simulated using Computational Fluid Dynamics, and the optimal hybrid structure was verified by tests. The results showed that ammonia leakage, low temperature crystallisation and NOX conversion efficiency could effectively be improved by optimally designing the new hybrid structure. This research is of great significance for reducing exhaust pollution and optimising diesel exhaust post-treatment systems.

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The Benefits of Diesel Exhaust Fluid (DEF) Additivation on Urea-Derived Deposits Formation in a Close-Coupled Diesel SCR on Filter Exhaust Line

Cited by 6 publications

References 21 publications

A conceptual design and numerical analysis of the mixerless urea-SCR system

A conceptual design and numerical analysis of the mixerless urea-SCR system

A CAN-Based Urea Line Heater Diagnostics Development and Experimental Validation for Selective Catalytic Reduction (SCR) System

Optimisation design of short pitch spiral hybrid SCR structure for improving the exhaust performance

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