Abstract

The uniformity of ammonia is very crucial for reducing the NOX emissions in a selective catalytic reduction system since the uniformity highly affects the chemical reaction between the ammonia and NOX emission. However, increasing ammonia uniformity in a short time period while injecting a urea solution is not a trivial task. Therefore, in this study, the uniformity of various urea injector designs is compared and an optimal design for the urea injector angle and direction is selected. The uniformity index (UI) was calculated using numerical analysis and compared with experimental result to achieve high reliability. The boundary condition of the analysis is extracted from the dominant operating region of the non-road transient cycle (NRTC) to guarantee a realistic analysis result. The design candidates were generated from the combination of three urea injection angles and eight urea injection directions and thoroughly compared to provide an insightful analysis. The conclusion is that injecting urea in the opposite direction to the main stream of exhaust gas increases the kinetic energy and thus the uniformity is highly increased. For example, urea injection in the opposite direction and angle to the mainstream flow could increase the UI to 0.966, which is a 16.7% improvement compared to the same direction and angle injection.

Highlights

  • Diesel engines have the advantages of a high thermal efficiency and reliability compared to other internal combustion engines

  • The existing aftertreatment equipment satisfied the exhaust gas regulations by installing a diesel oxidation catalyst (DOC), diesel particulate filter (DPF), or lean NOX trap (LNT), which operate without an additional injection system

  • The reliability of numerical analysis was determined based on an SCRinstalled exhaust gas aftertreatment device experiment

Read more

Summary

Introduction

Diesel engines have the advantages of a high thermal efficiency and reliability compared to other internal combustion engines. Despite the high thermal efficiency of compression ignition engines, these engines have the disadvantage of producing a large amount of exhaust gas compared to spark ignition engines. With increasing attention toward the environmental pollution of automobiles, strengthened emissions regulations were adopted, making the installation of additional aftertreatment equipment inevitable [2,3]. Three-way catalyst devices cannot be installed due to the low exhaust gas temperature and operating air–fuel ratio; numerous aftertreatment equipment installations are necessary [4,5]. The existing aftertreatment equipment satisfied the exhaust gas regulations by installing a diesel oxidation catalyst (DOC), diesel particulate filter (DPF), or lean NOX trap (LNT), which operate without an additional injection system

Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.