Ultra-Fine Particle Emissions Characterization and Reduction Technologies in a NG Heavy Duty Engine

Napolitano, Pierpaolo; Domenico, Davide Di; Maio, Dario Di; Guido, Chiara; Golini, Stefano

doi:10.3390/atmos13111919

Cited by 9 publications

(7 citation statements)

References 51 publications

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“…This reduction is attributed to the high conversion efficiency of UHC, thereby preventing particle formation [35] and enhancing the oxidation of small organic particles. Additionally, this capacity to oxidize small particles, coupled with potential agglomeration processes, led to a decrease in particles smaller than 23 nm, as previously documented in research under similar operating conditions [36,37]. This agglomeration process, particularly evident in modes M4 and M7, resulted in a slight increase in particles approximately 50 nm in diameter.…”

Section: Steady-state Conditionssupporting

confidence: 67%

Analysis of Particle Number Emissions in a Retrofitted Heavy Duty-Spark Ignition Engine Powered by LPG

Bermúdez,

Piqueras,

Sanchis

et al. 2024

Preprint

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This study aims to examine the non-volatile Particle Number (PN) emissions of a retrofitted Heavy-Duty Spark-Ignition (HD-SI) engine powered by liquefied petroleum gas (LPG) under both steady-state and transient conditions. The engine was tested under seven steady-state operating points to investigate the PN behavior and Particle Size Distribution (PSD) upstream and down-stream of the Three-Way Catalyst (TWC). This analysis intends to assess the impact of including particles with diameters ranging from 10 nm to 23 nm in the total particle count, a consideration for future regulations. The study employed the World Harmonized Transient Cycle (WHTC) for transient conditions to encompass the same engine working region used in the steady-state analysis. A Dekati FPS-4000 diluted the exhaust sample to measure the PSD and PN for particle diameters between 5.6 nm and 560 nm using the TSI-Engine Exhaust Particle Sizer (EEPS) 3090. Findings indicate that PN levels tend to increase downstream of the TWC under steady-state conditions in operating points with low exhaust gas temperatures and flows (equal to or less than 500 °C and 120 kg/h). Furthermore, the inclusion of particles with diameters between 10 nm and 23 nm leads to an increase in PN emissions by 17.70% to 40.84% under steady conditions and by an average of 40.06% under transient conditions, compared to measurements that only consider particles larger than 23 nm. Notably, in transient conditions, most PN emissions occur during the final 600 seconds of the cycle, linked to the most intense phase of the WHTC.

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Section: Steady-state Conditionssupporting

confidence: 67%

Analysis of Particle Number Emissions in a Retrofitted Heavy Duty-Spark Ignition Engine Powered by LPG

Bermúdez,

Piqueras,

Sanchis

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…This reduction is attributed to the high conversion efficiency of UHC, thereby preventing particle formation and enhancing the oxidation of small organic particles [17]. Additionally, this capacity to oxidize small particles, coupled with potential agglomeration processes, led to a decrease in particles smaller than 23 nm, as previously documented in research under similar operating con-ditions [46,47]. This agglomeration process, particularly evident in modes M4 and M7, resulted in a slight increase in particles approximately 50 nm in diameter.…”

Section: 𝑡 𝑥̅ 𝜇supporting

confidence: 52%

Analysis of Particle Number Emissions in a Retrofitted Heavy-Duty Spark Ignition Engine Powered by LPG

Bermúdez,

Piqueras,

Sanchis

et al. 2024

Atmosphere

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This study aims to examine the particle number (PN) emissions of a retrofitted heavy-duty spark ignition (HD-SI) engine powered by liquefied petroleum gas (LPG) under both steady-state and transient conditions. The engine was tested under seven steady-state operating points to investigate the PN behavior and particle size distribution (PSD) upstream and downstream of the three-way catalyst (TWC). This analysis intends to assess the impact of including particles with diameters ranging from 10 nm to 23 nm on the total particle count, a consideration for future regulations. The study employed the World Harmonized Transient Cycle (WHTC) for transient conditions to encompass the same engine working region as is used in the steady-state analysis. A Dekati FPS-4000 diluted the exhaust sample to measure the PSD and PN for particle diameters between 5.6 nm and 560 nm using the TSI-Engine Exhaust Particle Sizer (EEPS) 3090. The findings indicate that PN levels tend to increase downstream of the TWC under steady-state conditions in operating points with low exhaust gas temperatures and flows (equal to or less than 500 °C and 120 kg/h). Furthermore, the inclusion of particles with diameters between 10 nm and 23 nm leads to an increase in PN emissions by 17.70% to 40.84% under steady conditions and by an average of 40.06% under transient conditions, compared to measurements that only consider particles larger than 23 nm. Notably, in transient conditions, most PN emissions occur during the final 600 s of the cycle, linked to the most intense phase of the WHTC.

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“…For vehicles CNG and D1, the percentage is <50%, a number typical for light-duty vehicles [17] and some heavy-duty diesel engines [17,65,66]. CNG engines have a typically high percentage of sub-23 nm particles [17,19], but in our study, a particulate filter was installed, and thus the sub-23 nm particles were also captured efficiently [18,[67][68][69]. For D2 and D3, the percentages are very high (>50%) in the range of 7 × 10 10 #/kWh to 3 × 10 11 #/kWh.…”

Section: Vehicle Spn Emissionsmentioning

confidence: 75%

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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Ultra-Fine Particle Emissions Characterization and Reduction Technologies in a NG Heavy Duty Engine

Cited by 9 publications

References 51 publications

Analysis of Particle Number Emissions in a Retrofitted Heavy Duty-Spark Ignition Engine Powered by LPG

Analysis of Particle Number Emissions in a Retrofitted Heavy Duty-Spark Ignition Engine Powered by LPG

Analysis of Particle Number Emissions in a Retrofitted Heavy-Duty Spark Ignition Engine Powered by LPG

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

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