The effect of various urea-in-water solution types on exhaust particle number emission

Wang, Haohao; Zhai, Tianyu; Zhang, Lijun; Li, Jiachen; Xue, Zhentao; Wang, Jiaxing; Ji, Zhongrui; Li, Wanyang; Wang, Yibao

doi:10.1007/s11356-023-29971-y

Cited by 2 publications

(2 citation statements)

References 20 publications

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“…While some progress was made in understanding the effect of spray formation [43], mixing and decomposition processes [44], and urea solution composition [45] on particle formation, the potential offered in reducing SPN 10 emissions forming in SCR systems is still not well understood. Unless the emissions are reduced to a level below the proposed threshold within a safe engineering margin, a dedicated filter will be required.…”

Section: High Spn 10 Emissions From the Scr Systemmentioning

confidence: 99%

Diesel Particle Filter Requirements for Euro 7 Technology Continuously Regenerating Heavy-Duty Applications

Mamakos,

Rose,

Melas

et al. 2023

Vehicles

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The upcoming Euro 7 regulation for Heavy-Duty (HD) vehicles is calling for a further tightening of the Solid Particle Number (SPN) emissions by means of both lowering the applicable limits and shifting the lowest detectable size from 23 nm (SPN23) to 10 nm (SPN10). A late-technology diesel HD truck was tested on a chassis dynamometer in order to assess the necessary particle filtration requirements for a continuously regenerating system. The study showed that passive regeneration under real-world operating conditions can lead to a significant release of SPN10 particles from the current technology Diesel Particulate Filter (DPF) when soot-loaded, even exceeding the currently applicable emission limits. The actual emissions during passive regeneration and following the clean-up of the DPF exceeded the proposed Euro 7 limits by more than an order of magnitude. A prototype DPF, exhibiting a 99% filtration efficiency when clean, was shown to effectively control SPN10 emissions under both operating conditions. The shift to SPN10 also necessitates control of nanoparticles forming inside the Selective Catalytic Reduction (SCR) system, which for the tested truck exceeded the proposed (hot) limit by up to 56%. A dedicated particle filter specifically designed to capture these particles was also evaluated, showing a better than 60% efficiency. The key message of this study is that SPN emissions can be kept at low levels under all conditions.

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Section: High Spn 10 Emissions From the Scr Systemmentioning

confidence: 99%

Diesel Particle Filter Requirements for Euro 7 Technology Continuously Regenerating Heavy-Duty Applications

Mamakos,

Rose,

Melas

et al. 2023

Vehicles

View full text Add to dashboard Cite

show abstract

“…These particles are believed to be ammonium salts [24,25] or urea decomposition products (cyanuric acid and ammelide) [21,[26][27][28]. A recent study also found that different urea solutions can result in different increases in the SPN concentration for the same engine, and it was attributed to their different metallic element contents [29].…”

Section: Introductionmentioning

confidence: 99%

Solid Particle Number (SPN) Portable Emission Measurement Systems (PEMS) for Heavy-Duty Applications

Giechaskiel,

Melas,

Broekaert

et al. 2024

Applied Sciences

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A heavy-duty engine is homologated in a test cell. However, starting with Euro VI regulation, the in-service conformity is controlled with the engine installed in the vehicle using portable emission measurement systems (PEMS). In Europe, the application of solid particle number (SPN) PEMS started in 2021 for compression ignition (diesel) vehicles and in 2023 for positive ignition vehicles, thus including those operating with compressed natural gas (CNG). Even though today only particles with sizes > 23 nm are regulated, the Euro 7 proposal includes particles > 10 nm. There are not many studies on the accuracy of the SPN PEMS, especially for heavy-duty applications. In this study, PEMS measuring > 23 and >10 nm from two instrument manufacturers were compared with laboratory-grade instruments. The particle detector of one PEMS was a condensation particle counter (CPC), and of the other a the diffusion charger (DC). The results showed the robustness and good accuracy (40% or 1 × 1011 #/kWh) of the PEMS for ambient temperatures from −7 °C to 35 °C, active regeneration events, different fuels (Diesel B7, HVO, and CNG), different test cycles, cold start or hot engine operations, and high exhaust gas humidity content. Nevertheless, for the DC-based PEMS, sensitivity to pre-charged urea particles was identified, and for the CPC-based PEMS, sensitivity to pressure changes with one vehicle was nnoticed. Nevertheless, the results of this study confirm that the PEMS are accurate enough to measure even the stricter Euro 7 limits.

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The effect of various urea-in-water solution types on exhaust particle number emission

Cited by 2 publications

References 20 publications

Diesel Particle Filter Requirements for Euro 7 Technology Continuously Regenerating Heavy-Duty Applications

Diesel Particle Filter Requirements for Euro 7 Technology Continuously Regenerating Heavy-Duty Applications

Solid Particle Number (SPN) Portable Emission Measurement Systems (PEMS) for Heavy-Duty Applications

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