On the impact of DPF downsizing and cellular geometry on filtration efficiency in pre- and post-turbine placement

[EN] the current work a computational study to evaluate the effect of the DPF downsizing on filtration efficiency is performed. The DPF is conventionally placed downstream of the turbine. However, its placement upstream of the turbine is growing in interest because of the benefits in specific fuel consumption, passive regeneration and aptitude to downsizing. Hence both pre- and post-turbine placement are considered in presence of clean and soot loaded substrates. An in-house 1D wall-flow DPF model for unsteady compressible flow is used. Volume reduction is approached considering diameter and length variation. In parallel, the cell density is also varied modifying the meso-geometry, i.e. cell size and porous wall thickness, imposing constant thermal integrity factor. The sensitivity to this last parameter is also analysed resulting its influence of second order in comparison to volume and cellular geometry effects. The lower Peclet number in the pre-turbine placement leads to higher filtration efficiency than post-turbine location comparing at the same DPF volume. Diameter based volume reduction provides slightly better results in filtration efficiency than length based reduction because of the way the filtration velocity field is varied. This general behaviour involves additional advantages to the potential for volume reduction of pre-turbine DPFs. Thus, different strategies with boundaries defined by volume reduction at constant filtration area or at constant specific filtration area can be approached looking for the best balance between fuel economy reduction and filtration efficiency increase provided by pre-turbine DPF placement.This work has been partially funded by FEDER and Government of Spain through Project No. TRA2016-79185-R. Additionally, the Ph.D. student E. Angiolini has been funded by a grant from Conselleria de Educacio, Cultura i Esport of the Generalitat Valenciana with reference GRISOLIA/2013/036. These supports are gratefully acknowledged by the authors.Serrano, J.; Bermúdez, V.; Piqueras, P.; Angiolini, E. (2017). On the impact of DPF downsizing and cellular geometry on filtration efficiency in pre- and post-turbine placement. Journal of Aerosol Science. 113:20-35. https://doi.org/10.1016/j.jaerosci.2017.07.014S203511

Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters

Wall-flow type diesel particulate filter (DPF) is a required aftertreatment system for particle emission abatement and standards fulfilment in Diesel engines. However, the DPF use involves an important flow restriction, especially as the substrate gets soot and ash loaded. It gives as a result the increase of the exhaust back-pressure and hence a fuel consumption penalty. The increasing damage of fuel consumption with DPF soot loading leads to the need of the regeneration process. Usually based on active strategies, this process involves an additional fuel penalty but prevents from excessive DPF pressure drop and ensures secure soot burnt out. Under this context, new solutions are required to improve the state of the art DPF soot loading to pressure drop ratio. This paper presents a novel technique based on pre-DPF water injection to reduce the DPF pressure drop under soot loading conditions by disrupting its dependence on soot/ash loading. It provides benefits to engine fuel economy and also higher flexibility for DPF regeneration and maintenance. The work covers a test campaign performed in a passenger car turbocharged Diesel engine equipped with a wall-flow DPF. The main objective is to describe the technique, to provide a figure of its potential for pressure drop control and fuel consumption reduction. The results of the experiments also confirm soot and ash loading capacity increase and demonstrate the lack of negative effects on filtration efficiency and active and passive regeneration.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness through Grant No. TRA2013-40853-R.Bermúdez Tamarit, VR.; Serrano Cruz, JR.; Piqueras Cabrera, P.; García Afonso, Ó. (2015). Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters. Applied Energy. 140:234-245. https://doi.org/10.1016/j.apenergy.2014.12.003S23424514

Filtration modelling in wall-flow particulate filters of low soot penetration thickness

A filtration model for wall-flow particulate filters based on the theory of packed beds of spherical particles is presented to diagnose the combined response of filtration efficiency and pressure drop from a reliable computation of the flow field and the porous media properties. The model takes as main assumption the experimentally well-known low soot penetration thickness inside the porous wall. The analysis of soot loading processes in different particulate filters shows the ability of the proposed approach to predict the filtration efficiency as a function of the particle size distribution. Nevertheless, pressure drop and overall filtration efficiency are determined by the mode diameter of the raw particulate matter emission. The results reveal the dependence of the filtration efficiency in clean conditions on the sticking coefficient. However, the dynamics of the pressure drop and filtration efficiency as the soot loading varies is governed by the soot penetration thickness. This parameter is closely related to the porous wall Peclet number, which accounts for the porous wall and flow properties influence on the deposition process. The effect of the transition from deep bed to cake filtration regime on the pressure drop is also discussed underlying the importance of the macroscale over microscale phenomena.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness through Grant No. TRA2013-40853-R. Additionally, the Ph.D. student E. Angiolini has been funded by a grant from Conselleria de Educacio, Cultura i Esport of the Generalitat Valenciana with reference GRISOLIA/2013/036. These supports are gratefully acknowledged by the authors.Serrano Cruz, JR.; Climent, H.; Piqueras, P.; Angiolini, E. (2016). Filtration modelling in wall-flow particulate filters of low soot penetration thickness. Energy. 112:883-898. https://doi.org/10.1016/j.energy.2016.06.121S88389811

Packed bed of spherical particles approach for pressure drop prediction in wall-flow DPFs (diesel particulate filters) under soot loading conditions

The soot loading process in wall-flow DPFs (diesel particulate filters) affects the substrate structure depending on the filtration regime and produces the increase of pressure drop. Deep bed filtration regime produces the decrease of the porous wall permeability because of the soot particulates deposition inside it. Additionally, a layer of soot particulates grows on the porous wall surface when it becomes saturated. As soot loading increases, the pressure drop across the DPF depends on the porous wall and particulate layer permeabilities, which are in turn function of the substrate and soot properties. The need to consider the DPF pressure drop influence on engine performance analysis or DPF regeneration processes requires the use of low-computational effort models describing the structure of the soot deposition and its effect on permeability. This paper presents a model to describe the micro-scale of the porous wall and the particulate layer structure assuming them as packed beds of spherical particles. To assess the model s capability, it is applied to predict the DPF pressure drop under different experimental conditions in soot loading, mass flow and gas temperature.This work has been partially supported by the Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia through grant number SP20120340-UPPTE/2012/96 and by the Conselleria de Educacio, Cultura i Esport de la Generalitat Valenciana through grant number GV/2013/043.Serrano Cruz, JR.; Arnau Martínez, FJ.; Piqueras Cabrera, P.; García Afonso, Ó. (2013). Packed bed of spherical particles approach for pressure drop prediction in wall-flow DPFs (diesel particulate filters) under soot loading conditions. Energy. 58:644-654. https://doi.org/10.1016/j.energy.2013.05.051S6446545

Emotionale Intelligenz und ihre komplexe Beziehung zum Narzissmus

Drei grundsätzliche Ziele verfolgte diese Arbeit: Zunächst die Differenzierung von vulnerablem und grandiosem Narzissmus anhand der Beziehung zwischen Narzissmus und emotionaler Intelligenz. Des Weiteren soll Narzissmus zum ersten Mal mit Emotionsmanagement in Verbindung gebracht werden. Zuletzt sollte das neue Konstrukt „typisches Emotionsmanagement“ bezüglich seiner Zuordnung in die Persönlichkeitsdomäne der emotionalen Intelligenz (als verhaltensbezogener Indikator des sog. Trait EI) untersucht werden. Bei der Onlineuntersuchung wurden hierfür 151 Probanden gewonnen, die zwei Varianten des „Situational Test of Emotion Management“ (STEM) durchführten. Zur Erfassung der typischen Performanz (TP), wurde der neue STEM-TP verwendet, für die der maximalen Performanz (MP), der STEM-MP. Ferner bearbeiteten die Probanden die „Hypersensitive Narcissism Scale“ (HSNS) für den vulnerablen und die deutsche Kurzversion des „Narcissistic Personality Inventory“ (NPI-d) für den grandiosen Narzissmus. Ergänzend wurden die Kurzversionen der Fragebögen „Trait Emotional Intelligence Questionnaire“ (TEI-Que-SF) für die Messung des Trait EI und das „Big Five Inventory“ (BFI-K) für die Big Five Faktoren ausgefüllt. Die Ergebnisse weisen darauf hin, dass das neue Konstrukt STEM-TP nicht als verhaltensbezogener Indikator des Trait EI bezeichnet werden kann, da es in keiner signifikanten Beziehung zu den Persönlichkeitsmerkmalen (Trait EI, Narzissmus, Big Five) steht. Die Resultate bestärken auch die Notwendigkeit, vulnerablen und grandiosen Narzissmus zu differenzieren, insbesondere, wenn Persönlichkeitsmerkmale (hier: Emotionale Intelligenz über den Trait EI) über Selbsteinschätzungsverfahren ermittelt werden. Insgesamt legt diese Studie dar, dass bei der Definition der narzisstischen Persönlichkeitsstörung eine genauere Differenzierung und damit bessere Erfassung des vulnerablen Narzissmus durchgeführt werden muss.This study had three goals: First, the differentiation between vulnerable and grandiose narcissism by means of the relationship between narcissism and emotional intelligence. Second, for the first time narcissism is related to emotional management. At last, this Master thesis aims to examine the new construct “typical emotional management” regarding its place in the personality domain of emotional intelligence (as a behavioral indicator of the Trait EI). 151 participants were acquired for the online survey who carried out two versions of the Situation Test of Emotion Management (STEM). To evaluate the typical performance (TP), the newly developed STEM-TP was used and for the maximum performance (MP), the STEM-MP. Likewise, the participants had to finish the Hypersensitive Narcissism Scale (HSNS) for vulnerable narcissism and the German short version of the Narcissistic Personality Inventory (NPI-d) for grandiose narcissism. Additionally, the participants had to fill out the short version of the Trait Emotional Intelligence Questionnaire (TEI-Que-SF) for the measurement of Trait EI and the Big Five Inventory (BFI-K) to record the Big Five factors. The results indicate that the new construct STEM-TP cannot be labelled as a behavioral indicator of Trait EI because it has no significant relationship with the personality traits (Trait EI, narcissism, Big Five). Furthermore, the results confirm the necessity of the differentiation between vulnerable and grandiose narcissism, especially if the personality traits (in this study that is emotional intelligence as measured by Trait EI) are investigated by means of self-assessment tests. On the whole, this study shows, that when defining the narcissistic personality disorder, a more precise differentiation and a better evaluation of the vulnerable aspect of narcissism is needed.Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprüftAbweichender Titel laut Übersetzung des Verfassers/der VerfasserinKarl-Franzens-Universität Graz, Masterarbeit, 2020(VLID)482509

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