Analysis of the aftertreatment performance in HD-SI engine fueled with LPG

2021 ◽  
pp. 146808742110481
Author(s):  
Vicente Bermúdez ◽  
Santiago Ruiz ◽  
Brayan Conde ◽  
Lian Soto
Keyword(s):  
Pollutant Emissions ◽  
Gaseous Emissions ◽  
Si Engine ◽  
Diesel Particle Filter ◽  
Research Article ◽  
Particle Matter ◽  
In Series ◽  
Unburned Hydrocarbons ◽  
The Relationship ◽  
Three Way Catalyst

This research/article aimed to analyze the influence of an after-treatment system (ATS) on emissions of a heavy-duty spark-ignition (HD-SI) engine fueled with liquified petroleum gas (LPG), in the context of current Euro VI emissions requirements. The ATS is composed by a three-way catalyst (TWC) in series with a diesel particle filter (DPF). Emissions testing were carried out on an engine test bench according to homologation procedures, performing both world harmonized stationary cycle (WHSC) and world harmonized transient cycle (WHTC), to study the effects of the engine operating parameters on pollutant emissions behavior and ATS performance during steady and dynamic states, respectively. Instruments used were a gas analyzer Horiba MEXA ONE to measure gaseous emissions, HORIBA OBS ONE PN to measure particle matter (PM) concentration, and spectrometer TSI EEPS 3090 to measure PM concentration and particle size distribution (PSD). The results showed some important aspects such as the effects of engine speed and load on pollutant emissions formation and ATS performance, the influence of the three-way catalyst (TWC) on particulate matter (PM) reduction due to the relationship between volatile unburned hydrocarbons (UHC) and the emergence of nucleation-mode particles, stressing that ATS implementation is mandatory to meet the current emissions requirements.

scholarly journals Optimal Calibration Strategy of a Hybrid Electric Vehicle Equipped with an Ultra-Lean Pre-Chamber SI Engine for the Minimization of CO2 and Pollutant Emissions

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 4008
Author(s):  
Fabio Bozza ◽  
Vincenzo De Bellis ◽  
Enrica Malfi ◽  
Luigi Teodosio ◽  
Daniela Tufano
Keyword(s):  
Co2 Emissions ◽  
Hybrid Electric Vehicle ◽  
Electric Energy ◽  
Pollutant Emissions ◽  
Si Engine ◽  
Engine Calibration ◽  
Driving Cycles ◽  
In Series ◽  
1D Model ◽  
Variable Valve

The complexity of modern hybrid powertrains poses new challenges for the optimal control concerning, on one hand, the thermal engine to maximize its efficiency, and, on the other hand, the vehicle to minimize the noxious emissions and CO2. In this context, the engine calibration has to be conducted by considering simultaneously the powertrain management, the vehicle characteristics, and the driving mission. In this work, a calibration methodology for a two-stage boosted ultra-lean pre-chamber spark ignition (SI) engine is proposed, aiming at minimizing its CO2 and pollutant emissions. The engine features a flexible variable valve timing (VVT) control of the valves and an E-compressor, coupled in series to a turbocharger, to guarantee an adequate boost level needed for ultra-lean operation. The engine is simulated in a refined 1D model. A simplified methodology, based on a network of proportional integral derivative (PID) controllers, is presented for the calibration over the whole operating domain. Two calibration variants are proposed and compared, characterized by different fuel and electric consumptions: the first one aims to exclusively maximize the brake thermal efficiency, and the second one additionally considers the electric energy absorbed by the E-compressor and drained from the battery. After a verification against the outcomes of an automatic optimizer, the calibration strategies are assessed based on pollutant and CO2 emissions along representative driving cycles by vehicle simulations. The results highlight slightly lower CO2 emissions with the calibration approach that minimizes the E-compressor consumption, thus revealing the importance of considering the engine calibration phase, the powertrain management, the vehicle characteristics, and its mission.

scholarly journals Particle matter from a diesel engine fueled with Jatropha curcas oil biodiesel and ultra-low sulphur diesel

2012 ◽  
Vol 5 (1) ◽  
pp. 83-92
Author(s):  
Helmer-Rodolfo Acevedo-Gamboa ◽  
Elkin-Greforio Flórez-Serrano
Keyword(s):  
Diesel Engine ◽  
Alternative Fuels ◽  
Fossil Fuels ◽  
Fuel Injection ◽  
Substantial Reduction ◽  
Gaseous Emissions ◽  
Performance And Emission ◽  
Particle Matter ◽  
Unburned Hydrocarbons ◽  
Heavy Duty Diesel

Biodiesels are promoted as alternative fuels due to their potential to reduce dependency on fossil fuels and carbon emissions. Research in this field has focused on the study of the emissions of light duty vehicles. However, particle matter and gaseous emissions emitted from heavy-duty diesel engines fueled by Jatropha Oil Biodiesel (JOB) and Ultra-Low Sulphur Diesel (ULSD) has not been studied. The objective of this study is to explore the performance and emission levels of a Cummins 4-stroke, 4.8 liter, 4-cylinder diesel engine with common rail fuel injection, equipped with a cooled Exhaust Gas Recirculation (EGR). There was a substantial reduction by the use of JOB in unburned hydrocarbons (- 45%), carbon monoxide (- 75%), and particulate matter (- 25%) compared to emission from diesel fuel. At mid and high loads, NOx emissions were higher for JOB compared to ULSD. Most of the particles (64%) for ULSD were in a range of between 40 and 560 nm. On the other hand, most of the particles (94%) for JCB mode were between 6 and 40 nm. In the range between 6 and 40 nm, mass mean diameters in ULSD were 34.4, 34.7 and 33.3 nm while for JOB they were 21.3, 18.2 and 20.1 nm for 100, 50 for a 10% load, respectively. 

scholarly journals How Does Environmental Regulation Affect the Relationship between FDI and Technological Innovation: From the Perspective of Technology Transactions

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1264
Author(s):  
Meng Zeng ◽  
Lihang Liu ◽  
Fangyi Zhou ◽  
Yigui Xiao
Keyword(s):  
Environmental Regulation ◽  
Technological Innovation ◽  
Pollutant Emissions ◽  
Regulatory Effect ◽  
Host Countries ◽  
Regional Heterogeneity ◽  
Industrial Sectors ◽  
Reduction Effect ◽  
The Impact ◽  
The Relationship

Many studies have found that FDI can reduce the pollutant emissions of host countries. At the same time, the intensity of environmental regulation would affect the emission reduction effect of FDI in the host country. This study aims to reveal the internal mechanisms of this effect. Specifically, this paper studies the impact of FDI on technological innovation in China’s industrial sectors from the perspective of technology transactions from 2001 to 2019, and then analyzes whether the intensity of environmental regulation can promote the relationship. Results indicate that FDI promotes technological innovation through technology transactions. In addition, it finds that the intensity of environmental regulation significantly positively moderates the relationship between FDI and technological innovation, which is achieved by positively moderating the FDI–technology transaction relationship. Regional heterogeneity analysis is further conducted, and results show that in the eastern and western regions of China, FDI can stimulate technological innovation within regional industrial sectors through technology trading. Moreover, environmental regulation has a significant positive regulatory effect on the above relationship, but these effects are not supported by evidence in the central region of China.

A phenomenological model for the description of unburned hydrocarbons emission in ultra-lean engines

2021 ◽  
pp. 146808742110050
Author(s):  
Enrica Malfi ◽  
Vincenzo De Bellis ◽  
Fabio Bozza ◽  
Alberto Cafari ◽  
Gennaro Caputo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Pollutant Emissions ◽  
Average Error ◽  
Combustion Engines ◽  
Nitric Oxides ◽  
Lean Burn ◽  
Fuel Charge ◽  
Unburned Hydrocarbons ◽  
Model Reliability

The adoption of lean-burn concepts for internal combustion engines working with a homogenous air/fuel charge is under development as a path to simultaneously improve thermal efficiency, fuel consumption, nitric oxides, and carbon monoxide emissions. This technology may lead to a relevant emission of unburned hydrocarbons (uHC) compared to a stoichiometric engine. The uHC sources are various and the relative importance varies according to fuel characteristics, engine operating point, and some geometrical details of the combustion chamber. This concern becomes even more relevant in the case of engines supplied with natural gas since the methane has a global warming potential much greater than the other major pollutant emissions. In this work, a simulation model describing the main mechanisms for uHC formation is proposed. The model describes uHC production from crevices and flame wall quenching, also considering the post-oxidation. The uHC model is implemented in commercial software (GT-Power) under the form of “user routine”. It is validated with reference to two large bore engines, whose bores are 31 and 46 cm (engines named accordingly W31 and W46). Both engines are fueled with natural gas and operated with lean mixtures (λ > 2), but with different ignition modalities (pre-chamber device or dual fuel mode). The engines under study are preliminarily schematized in the 1D simulation tool. The consistency of 1D engine schematizations is verified against the experimental data of BMEP, air flow rate, and turbocharger rotational speed over a load sweep. Then, the uHC model is validated against the engine-out measurements. The averaged uHC predictions highlight an average error of 7% and 10 % for W31 and W46 engines, respectively. The uHC model reliability is evidenced by the lack of need for a case-dependent adjustment of its tuning constants, also in presence of relevant variations of both engine load and ring pack design.

scholarly journals State of Art of Using Biofuels in Spark Ignition Engines

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 779
Author(s):  
Ashraf Elfasakhany
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Pollutant Emissions ◽  
Spark Ignition Engines ◽  
Engine Emissions ◽  
Cold Starting ◽  
Starting Conditions ◽  
Unburned Hydrocarbons ◽  
Scientific Attention ◽  
State Of Art

Biofuels are receiving increased scientific attention, and recently different biofuels have been proposed for spark ignition engines. This paper presents the state of art of using biofuels in spark ignition engines (SIE). Different biofuels, mainly ethanol, methanol, i-butanol-n-butanol, and acetone, are blended together in single dual issues and evaluated as renewables for SIE. The biofuels were compared with each other as well as with the fossil fuel in SIE. Future biofuels for SIE are highlighted. A proposed method to reduce automobile emissions and reformulate the emissions into new fuels is presented and discussed. The benefits and weaknesses of using biofuels in SIE are summarized. The study established that ethanol has several benefits as a biofuel for SIE; it enhanced engine performance and decreased pollutant emissions significantly; however, ethanol showed some drawbacks, which cause problems in cold starting conditions and, additionally, the engine may suffer from a vapor lock situation. Methanol also showed improvements in engine emissions/performance similarly to ethanol, but it is poisonous biofuel and it has some sort of incompatibility with engine materials/systems; its being miscible with water is another disadvantage. The lowest engine performance was displayed by n-butanol and i-butanol biofuels, and they also showed the greatest amount of unburned hydrocarbons (UHC) and CO emissions, but the lowest greenhouse effect. Ethanol and methanol introduced the highest engine performance, but they also showed the greatest CO2 emissions. Acetone introduced a moderate engine performance and the best/lowest CO and UHC emissions. Single biofuel blends are also compared with dual ones, and the results showed the benefits of the dual ones. The study concluded that the next generation of biofuels is expected to be dual blended biofuels. Different dual biofuel blends are also compared with each other, and the results showed that the ethanol–methanol (EM) biofuel is superior in comparison with n-butanol–i-butanol (niB) and i-butanol–ethanol (iBE).

scholarly journals The Transport of Salt and Water across Isolated Rat Ileum

1967 ◽  
Vol 50 (3) ◽  
pp. 695-727 ◽  
Author(s):  
T. W. Clarkson
Keyword(s):  
Active Transport ◽  
Transport Processes ◽  
Irreversible Processes ◽  
Pressure Gradients ◽  
Ion Flow ◽  
Chemical Gradients ◽  
In Series ◽  
Frictional Coefficients ◽  
The Relationship ◽  
Active Channel

The flows of sodium, potassium, and chloride under electrical and chemical gradients and of salt and water in the presence of osmotic pressure gradients are described by phenomenological equations based on the thermodynamics of irreversible processes. The aim was to give the simplest possible description, that is to postulate the least number of active transport processes and the least number of separate pathways across the intestine. On this basis, the results were consistent with the following picture of the intestine: Two channels exist across this tissue, one allowing only passive transport of ions and the other only active. In the passive channel, the predominant resistance to ion flow is friction with the water in the channel. The electroosmotic flow indicates that the passive channel is lined with negative fixed charged groups having a surface charge density of 3000 esu cm-2. The values of the ion-water frictional coefficients, and the relationship between ionic concentrations and flows indicate that the passive channel is extracellular. The active channel behaves as two membranes in series, the first membrane being semipermeable but allowing active transport of sodium, and the second membrane being similar to the passive channel. Friction with the ions in the second "membrane" is the predominant resistance to water flow.

scholarly journals Determining the environmental indicators for vehicles of different categories in relation to CO2 emission based on road tests

2017 ◽  
Vol 170 (3) ◽  
pp. 66-72
Author(s):  
Jerzy MERKISZ ◽  
Łukasz RYMANIAK
Keyword(s):  
Co2 Emissions ◽  
Operating Time ◽  
Environmental Indicators ◽  
Operating Conditions ◽  
Si Engine ◽  
Propulsion Systems ◽  
System A ◽  
In Series ◽  
Series Configuration ◽  
Ci Engine

The article discusses the possibility of determining the environmental indicators for vehicles of different categories in relation to CO2 emissions. These are called toxicity indicators because they concern the compounds: CO, THC and NOx. Three Euro V compliant vehicles with different propulsion systems types were used for the study: a 0.9 dm3 urban passenger car with a SI engine and a start-stop system, a 2.5 dm3 off-road vehicle with a CI engine, and a city bus with a hybrid drive system in series configuration and a CI engine with a displacement of 6.7 dm3. Measurements were made in actual operating conditions in the Poznan agglomeration using a portable emissions measurement system (PEMS). The paper presents the characteristics of the operating time shares of vehicles and propulsion systems as well as CO2 emissions depending on the engine load and crankshaft rotational speed for individual vehicles. The determined toxicity indicators allowed to indicate their usefulness, to make comparisons between tested vehicles, and to identify directions for further work on the application and interpretation of these indicators.

scholarly journals Organisational Culture and Corporate Performance: Empirical Evidence from Nigeria

2010 ◽  
Vol 5 (2) ◽  
Author(s):  
Olu Ojo
Keyword(s):  
Corporate Performance ◽  
Organisational Culture ◽  
Vital Role ◽  
Study Data ◽  
Primary Data ◽  
Cultural Norms ◽  
Organisational Performance ◽  
Business Context ◽  
Research Article ◽  
The Relationship

The purpose of this research article is to examine various concepts on organisational culture and strives to ascertain the importance of the relationship between organisational culture and corporate performance in a business context. The study adopted survey research design. The population of this study is the entire employees of Nigerian commercial banks. Primary data were used for this study. Data were collected through a questionnaire that was administered to the selected respondents, The two hypotheses proffered were tested and relevant recommendations were made. The conclusion drawn from the study is that organisational culture plays a vital role in an organisation’s general performance. This study contributes to organisational culture’s literature by showing that employees would commit themselves to organisational goals and work actively in achieving those goals when they buy into cultural norms of the organisation and thus increase organisational performance.

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