Giorgio Zamboni | Università degli Studi di Genova (original) (raw)
Papers by Giorgio Zamboni
Biomass & Bioenergy, Jul 1, 2021
Abstract An extended investigation on the application of blends between diesel oil and used cooki... more Abstract An extended investigation on the application of blends between diesel oil and used cooking oil methyl esters (UCOME) was developed on an automotive turbocharged diesel engine. Two commercial diesel oils were considered as reference fuels, the first with the conventional content of biodiesel (7%), the second with an amount of 15%. Then, increasing levels of UCOME were added, on a volumetric basis (20%, 40%, 55 or 60%), to analyse the influence of biodiesel content on engine behaviour. Three part load engine operating conditions were selected for tests, measuring average engine parameters and indicated pressure diagrams. Their processing allowed to calculate the most important operating, energy and environmental engine quantities, rate of heat release and related combustion parameters. A proper management of the exhaust gas recirculation circuit, variable nozzle turbine and injection system was applied thanks to the availability of an open electronic control unit. An optimal UCOME content (40%) was identified, leading to highest values of brake thermal efficiency (with maximum increase around 5% referring to baseline fuels) and lowest levels of NOX emissions. For this blend, the analysis of combustion parameters outlined that the use of the renewable fuel corresponded to an enhanced premixed combustion phase, while reducing combustion duration. Lower local temperature levels, related to the decrease of Lower Heating Value, other local effects and biodiesel degree of unsaturation justify NOX reduction. Furthermore, soot emissions were always reduced when increasing biodiesel content, while combustion stability was not affected. All these outcomes were observed with and without EGR.
Applied Energy, 2016
An experimental investigation was made on a downsized Euro 5 turbocharged diesel engine managing ... more An experimental investigation was made on a downsized Euro 5 turbocharged diesel engine managing high/low pressure EGR systems and the variable nozzle turbine, aiming at major reductions in NOX emissions while enhancing fuel consumption in comparison with reference configuration. Three part load engine operating conditions were chosen at low and medium speed levels, applying different strategies to a number of control variables (relative air–fuel ratio, VNT opening degree/intake pressure, valves position in low pressure EGR circuit), thus exploring the whole range of high/low pressure EGR proportion. In suitable operating modes of tested conditions, NOX emissions were reduced up to 58–66%. Brake specific fuel consumption decreased around 5–9.5% at low speed/load, 1.7–3.3% in the intermediate condition while no advantages were achieved in the third working point. The activation of low pressure loop confirmed to be beneficial for turbocharger performance, rising its rotational speed thus granting for a better transient response, while increase in soot emissions ranged in a wide interval. For each condition, optimal operating modes were identified, with the relevant EGR proportion. A prevailing contribution from the long route circuit was generally requested, up to the exclusion of short route loop at higher level of speed and load.
Volume 6: Energy, Parts A and B, 2012
ABSTRACT An experimental and theoretical investigation is being performed with a view to evaluate... more ABSTRACT An experimental and theoretical investigation is being performed with a view to evaluate the contribution of Heavy duty vehicles (HDVs) to exhaust emissions and fuel consumption in urban areas involved by commercial shipping activities. Reference is made to the city of Genoa, whose urban road network is influenced both by shipping activities and highway connections, as more than twenty accesses to port area and seven motorway exits are available within the urban area. Different aspects were deepened in this study. Firstly, the HDV flows crossing highway exits, urban zones and port areas were assessed, as well as the relevant vehicle classes. Secondly, the typical urban trips linking highway exits to port gates and the HDV mission profiles within the port area were identified. Measurements of HDV instantaneous speed related to the urban trips were then planned aiming at the definition of the most representative speed patterns through a proper statistical data processing, enabling the application of Passenger Car and Heavy Duty Emission Model (PHEM) for the estimation of emission and fuel consumption factors for selected HDV classes. The main results of the different investigation steps are presented and discussed in the paper, outlining the peculiar mission of HDVs in port area and the related emissive behavior.
Volume 6: Energy, Parts A and B, 2012
A wide experimental investigation was performed on a CFR engine with a view to comparing differen... more A wide experimental investigation was performed on a CFR engine with a view to comparing different renewable fuels in terms of Cetane Number, engine brake thermal efficiency and exhaust emissions. The CFR engine available at the Internal Combustion Engines Group of the University of Genoa was properly modified and fully instrumented in order to control operating conditions and to measure the average engine parameters and in-cylinder pressure diagrams. Aiming at the comparison of fuels obtained from various feedstock, an experimental procedure was then defined, including the standard Cetane Number evaluation and the definition of engine operating quantities in 16 different working points, considering four levels of rotational speed and load, for fixed levels of compression ratio and injection advance. Methyl-esters of rapeseed oil and of vegetable oils mix were investigated, while rapeseed, palm and coconut oil were also available. Several blends, obtained by mixing different biodies...
International Journal of Green Energy, 2015
ABSTRACT A CFR engine was modified and instrumented in order to control operating conditions and ... more ABSTRACT A CFR engine was modified and instrumented in order to control operating conditions and to measure engine parameters and in-cylinder pressure diagrams. Aiming at the comparison of different alternative fuels, an experimental procedure was defined, including Cetane Number evaluation and the definition of engine operating quantities in different working points, for fixed levels of compression ratio and injection advance. An investigation was made considering several blends of methyl-esters of rapeseed oil and of a mix of vegetable oils with conventional diesel oil. The defined experimental procedure was applied to assess Cetane Number, engine brake thermal efficiency and exhaust emissions. Results show that the biodiesel content has a positive influence on soot emissions, with strong reduction, while thermal efficiency and NOx emissions are negatively affected, which can be justified taking into account fuel properties and changes in combustion process. As observed outcomes are generally in line with those presented in literature, the facility proved to be a suitable tool for basic investigations on alternative fuels to be used in specific applications.
SAE Technical Paper Series, 2007
Abstract: Cold start effect is one of the most significant item for real world emissions evaluati... more Abstract: Cold start effect is one of the most significant item for real world emissions evaluation: engine and after-treatment system transient behaviour leads to high levels of pollutants, generally exhausted in urban driving mode. In this paper, literature data referred to cold transient are summarized for some motorcycle classes. The main results of an experimental activity, performed to characterize the cold emissive behaviour of a 125 cc 4-stroke Euro 3 motorcycle during different driving cycles, are then presented. Finally, a ...
International Journal of Heat and Fluid Flow, 2014
ABSTRACT Downsizing with turbocharging is the most promising way, especially in terms of cost, to... more ABSTRACT Downsizing with turbocharging is the most promising way, especially in terms of cost, to get reduced fuel consumption and CO2 emissions particularly in the case of Spark Ignition engines. In automotive applications the turbocharger turbine usually operates under heavy unsteady flow conditions due to the opening and closing of engine valves. However, in the case of extremely downsized engines with a reduced number of cylinders and a small intake circuit volume also the compressor performance can be affected by the unsteady flow generated by the engine intake valves. To make simulation models able to accurately predict engine performance, a better understanding of compressor and turbine pulsating flow performance can be accomplished through measurements performed on specialized test facilities, using suitable measuring equipment. As regards the turbocharger compressor, the surge line position under pulsating flow conditions is another important aspect to be considered. In the paper the results of a broad experimental investigation performed on a small turbocharger compressor matched to a downsized gasoline engine are presented. Measurements were developed on the test facility operating at the University of Genoa, which allows investigations on automotive turbochargers both under steady and unsteady flow conditions. Tested turbocharger compressor was coupled to the automotive engine intake circuit and the pulsating flow was generated by a motor-driven cylinder head fitted with a variable valve actuation system. Different levels of turbocharger rotational speed and different intake valve opening strategies were considered. For each operating condition compressor unsteady performance was evaluated starting from measurement of several instantaneous parameters (inlet and outlet static pressure, mass flow rate and turbocharger rotational speed). A significant deviation of compressor instantaneous performance from steady state was observed, resulting in a hysteresis loop surrounding the steady state curve.
Experimental Thermal and Fluid Science, 2014
To make simulation models able to accurately predict engine performance, a better understanding o... more To make simulation models able to accurately predict engine performance, a better understanding of compressor behavior over an extended range can be accomplished by using a specialized test facility and measuring equipment. Besides, the correct surge line position is another important aspect to be considered to optimize engine-turbocharger matching calculation. In the paper the results of an experimental investigation developed on a turbocharger compressor for heavy duty vehicle application is presented. The study was focused on the definition of surge line position adopting different methods and on the evaluation of compressor performance over an extended range, taking into account compressor behavior both in the stable and unstable operating region.
Applied Energy, 2013
ABSTRACT An experimental and theoretical investigation is being performed to evaluate exhaust emi... more ABSTRACT An experimental and theoretical investigation is being performed to evaluate exhaust emissions and fuel consumption of Heavy Duty Vehicles (HDVs) circulating in urban areas and involved in commercial shipping activities. The study is focused on the city of Genoa, whose urban road network is influenced by highway connections and shipping activities, as seven motorway exits and more than twenty accesses to port area are located within the urban area. In a first step, the HDV flows crossing highway exits, urban zones and port areas were evaluated, as well as the relevant vehicle classes. The typical urban trips linking highway exits to port gates and the HDV mission profiles within the port area were then defined, whose validation was performed through an experimental campaign for HDV instantaneous speed measurements on urban trips and in port zones. The availability of speed patterns enabled the application of Passenger Car and Heavy Duty Emission Model (PHEM) for the estimation of fuel consumption and emission factors for selected HDV classes. The main results of the different investigation steps are presented and discussed in the paper, outlining the specific activities of HDVs in port area and the relevant emissive behaviour.
SAE Technical Paper Series, 2005
ABSTRACT The paper presents the main results of a study focused on the definition of exhaust emis... more ABSTRACT The paper presents the main results of a study focused on the definition of exhaust emission factors for a waste collection vehicles fleet, taking into account the specific emission profiles. As a first step, on the basis of the fleet characteristics, different classification criteria were applied, aiming at the identification of suitable vehicle classes. Then, the calculation of the exhaust emissions for each class was based on a two terms equation, the first related to the vehicle travel (considering different sources for the relevant emission factors) and the second to the equipment use, whose contribution is estimated on the basis of different parameters. A computational code was then set up for the evaluation of the daily emission of normalised pollutants for the whole fleet and each required service. The results of different calculations are presented in the paper, referring to the distribution of total emissions between the different vehicles categories and classes, the estimation of the waste fleet contribution to the overall pollution due to road transport in Genoa urban area and the effects of the fleet renewal.
L’attività oggetto del presente lavoro rientra nell’indagine finalizzata allo studio delle emissi... more L’attività oggetto del presente lavoro rientra nell’indagine finalizzata allo studio delle emissioni dei motocicli, congiuntamente sviluppata dall’Istituto Motori del CNR e dall’Internal Combustion Engines Group operante presso il Dipartimento di Macchine, Sistemi Energetici e Trasporti dell’Università di Genova. Due scooter 4T, omologati secondo la normativa Euro 3 per le emissioni allo scarico, sono stati testati su banco a rulli con diversi cicli di guida, sia di omologazione che reali, al fine di stimarne i fattori di emissione (con riferimento a CO, HC, NOx e CO2) ed il consumo di combustibile sia in condizioni di funzionamento a caldo (motore e fluidi regimati termicamente) che con partenza a freddo. Nel lavoro viene analizzata l’influenza dei cicli considerati sui fattori misurati e sul comportamento a freddo dei veicoli analizzati, in termini di sovraemissioni, durata del transitorio e relativa distanza percorsa ed effettuato un confronto dei dati sperimentali con quelli app...
A computer PROGramme for Road vehicles EmiSSions evaluation (PROGRESS) was developed in order to ... more A computer PROGramme for Road vehicles EmiSSions evaluation (PROGRESS) was developed in order to assess the environmental impact from road traffic under real urban driving conditions. The procedure takes into account different aspects, i.e., the estimation of circulating fleet and the relevant urban driving statistics, the definition of typical urban trips and the evaluation of emission factors from road vehicles in urban environment. In the present release, PROGRESS allows to calculate the total mass of normalised pollutants at the exhaust of eight different vehicles categories, referring to the whole urban area (or part of it) and to different periods of time (ranging from one hour to one year). In the paper the main characteristics of the PROGRESS code are presented, with reference to its structure, to the calculation procedure of hot, cold and total emissions and to the outputs. Finally an application is presented and discussed, referring to the city of Genoa.
International Journal of Environmental Studies
ABSTRACT A simulation tool was developed to evaluate variations in exhaust emissions from cars wh... more ABSTRACT A simulation tool was developed to evaluate variations in exhaust emissions from cars when replacing conventional powertrains with electric or hybrid propulsion systems. The model permits calculation of direct emissions (released at the vehicles’ exhaust) and indirect emissions (released when producing electricity for batteries recharging). To verify model outputs, a reference scenario was defined selecting the urban area of Genoa, Italy, considering the number of vehicles and mileage of eight vehicle categories. A simulated scenario was then designed, replacing cars belonging to older legally defined classes with electric and hybrid ones. Significant reductions were estimated for regulated pollutants, with higher benefits estimated for CO and NOX emissions, deriving from calculated reductions and contributions of cars in the reference scenario. No advantages were estimated for CO2, outlining that a change in the national mix for electricity production is also required.
Cogent Engineering
The influence of rail pressure control on fuel consumption, emissions and combustion in an automo... more The influence of rail pressure control on fuel consumption, emissions and combustion in an automotive downsized turbocharged diesel engine was investigated, considering different operating modes in three-part load working conditions. These modes were selected according to the results of a previous step of the study, where low NO X and fuel consumption levels were obtained managing a hybrid exhaust gas recirculation (EGR) system and the turbocharger variable nozzle turbine (VNT). Aiming at limiting observed soot penalties, increased values of rail pressure were applied, deepening the interactions with engine-controlled sub-assemblies and the related variations in operating, environmental, energy and combustion parameters. At low levels of engine speed and load, major reduction in NO X emissions and fuel consumption were observed, with acceptable soot and noise combustion increase, while turbocharger speed was also enhanced. No variations in fuel consumption were achieved at higher load and speed, while soot penalty remained significant. A simplified method to describe and model engine behaviour and combustion process was also developed, defining linear relationships between rail pressure and engine quantities, including a wide set of combustion parameters derived from in-cylinder pressure diagrams and heat release curves.
Biomass & Bioenergy, Jul 1, 2021
Abstract An extended investigation on the application of blends between diesel oil and used cooki... more Abstract An extended investigation on the application of blends between diesel oil and used cooking oil methyl esters (UCOME) was developed on an automotive turbocharged diesel engine. Two commercial diesel oils were considered as reference fuels, the first with the conventional content of biodiesel (7%), the second with an amount of 15%. Then, increasing levels of UCOME were added, on a volumetric basis (20%, 40%, 55 or 60%), to analyse the influence of biodiesel content on engine behaviour. Three part load engine operating conditions were selected for tests, measuring average engine parameters and indicated pressure diagrams. Their processing allowed to calculate the most important operating, energy and environmental engine quantities, rate of heat release and related combustion parameters. A proper management of the exhaust gas recirculation circuit, variable nozzle turbine and injection system was applied thanks to the availability of an open electronic control unit. An optimal UCOME content (40%) was identified, leading to highest values of brake thermal efficiency (with maximum increase around 5% referring to baseline fuels) and lowest levels of NOX emissions. For this blend, the analysis of combustion parameters outlined that the use of the renewable fuel corresponded to an enhanced premixed combustion phase, while reducing combustion duration. Lower local temperature levels, related to the decrease of Lower Heating Value, other local effects and biodiesel degree of unsaturation justify NOX reduction. Furthermore, soot emissions were always reduced when increasing biodiesel content, while combustion stability was not affected. All these outcomes were observed with and without EGR.
Applied Energy, 2016
An experimental investigation was made on a downsized Euro 5 turbocharged diesel engine managing ... more An experimental investigation was made on a downsized Euro 5 turbocharged diesel engine managing high/low pressure EGR systems and the variable nozzle turbine, aiming at major reductions in NOX emissions while enhancing fuel consumption in comparison with reference configuration. Three part load engine operating conditions were chosen at low and medium speed levels, applying different strategies to a number of control variables (relative air–fuel ratio, VNT opening degree/intake pressure, valves position in low pressure EGR circuit), thus exploring the whole range of high/low pressure EGR proportion. In suitable operating modes of tested conditions, NOX emissions were reduced up to 58–66%. Brake specific fuel consumption decreased around 5–9.5% at low speed/load, 1.7–3.3% in the intermediate condition while no advantages were achieved in the third working point. The activation of low pressure loop confirmed to be beneficial for turbocharger performance, rising its rotational speed thus granting for a better transient response, while increase in soot emissions ranged in a wide interval. For each condition, optimal operating modes were identified, with the relevant EGR proportion. A prevailing contribution from the long route circuit was generally requested, up to the exclusion of short route loop at higher level of speed and load.
Volume 6: Energy, Parts A and B, 2012
ABSTRACT An experimental and theoretical investigation is being performed with a view to evaluate... more ABSTRACT An experimental and theoretical investigation is being performed with a view to evaluate the contribution of Heavy duty vehicles (HDVs) to exhaust emissions and fuel consumption in urban areas involved by commercial shipping activities. Reference is made to the city of Genoa, whose urban road network is influenced both by shipping activities and highway connections, as more than twenty accesses to port area and seven motorway exits are available within the urban area. Different aspects were deepened in this study. Firstly, the HDV flows crossing highway exits, urban zones and port areas were assessed, as well as the relevant vehicle classes. Secondly, the typical urban trips linking highway exits to port gates and the HDV mission profiles within the port area were identified. Measurements of HDV instantaneous speed related to the urban trips were then planned aiming at the definition of the most representative speed patterns through a proper statistical data processing, enabling the application of Passenger Car and Heavy Duty Emission Model (PHEM) for the estimation of emission and fuel consumption factors for selected HDV classes. The main results of the different investigation steps are presented and discussed in the paper, outlining the peculiar mission of HDVs in port area and the related emissive behavior.
Volume 6: Energy, Parts A and B, 2012
A wide experimental investigation was performed on a CFR engine with a view to comparing differen... more A wide experimental investigation was performed on a CFR engine with a view to comparing different renewable fuels in terms of Cetane Number, engine brake thermal efficiency and exhaust emissions. The CFR engine available at the Internal Combustion Engines Group of the University of Genoa was properly modified and fully instrumented in order to control operating conditions and to measure the average engine parameters and in-cylinder pressure diagrams. Aiming at the comparison of fuels obtained from various feedstock, an experimental procedure was then defined, including the standard Cetane Number evaluation and the definition of engine operating quantities in 16 different working points, considering four levels of rotational speed and load, for fixed levels of compression ratio and injection advance. Methyl-esters of rapeseed oil and of vegetable oils mix were investigated, while rapeseed, palm and coconut oil were also available. Several blends, obtained by mixing different biodies...
International Journal of Green Energy, 2015
ABSTRACT A CFR engine was modified and instrumented in order to control operating conditions and ... more ABSTRACT A CFR engine was modified and instrumented in order to control operating conditions and to measure engine parameters and in-cylinder pressure diagrams. Aiming at the comparison of different alternative fuels, an experimental procedure was defined, including Cetane Number evaluation and the definition of engine operating quantities in different working points, for fixed levels of compression ratio and injection advance. An investigation was made considering several blends of methyl-esters of rapeseed oil and of a mix of vegetable oils with conventional diesel oil. The defined experimental procedure was applied to assess Cetane Number, engine brake thermal efficiency and exhaust emissions. Results show that the biodiesel content has a positive influence on soot emissions, with strong reduction, while thermal efficiency and NOx emissions are negatively affected, which can be justified taking into account fuel properties and changes in combustion process. As observed outcomes are generally in line with those presented in literature, the facility proved to be a suitable tool for basic investigations on alternative fuels to be used in specific applications.
SAE Technical Paper Series, 2007
Abstract: Cold start effect is one of the most significant item for real world emissions evaluati... more Abstract: Cold start effect is one of the most significant item for real world emissions evaluation: engine and after-treatment system transient behaviour leads to high levels of pollutants, generally exhausted in urban driving mode. In this paper, literature data referred to cold transient are summarized for some motorcycle classes. The main results of an experimental activity, performed to characterize the cold emissive behaviour of a 125 cc 4-stroke Euro 3 motorcycle during different driving cycles, are then presented. Finally, a ...
International Journal of Heat and Fluid Flow, 2014
ABSTRACT Downsizing with turbocharging is the most promising way, especially in terms of cost, to... more ABSTRACT Downsizing with turbocharging is the most promising way, especially in terms of cost, to get reduced fuel consumption and CO2 emissions particularly in the case of Spark Ignition engines. In automotive applications the turbocharger turbine usually operates under heavy unsteady flow conditions due to the opening and closing of engine valves. However, in the case of extremely downsized engines with a reduced number of cylinders and a small intake circuit volume also the compressor performance can be affected by the unsteady flow generated by the engine intake valves. To make simulation models able to accurately predict engine performance, a better understanding of compressor and turbine pulsating flow performance can be accomplished through measurements performed on specialized test facilities, using suitable measuring equipment. As regards the turbocharger compressor, the surge line position under pulsating flow conditions is another important aspect to be considered. In the paper the results of a broad experimental investigation performed on a small turbocharger compressor matched to a downsized gasoline engine are presented. Measurements were developed on the test facility operating at the University of Genoa, which allows investigations on automotive turbochargers both under steady and unsteady flow conditions. Tested turbocharger compressor was coupled to the automotive engine intake circuit and the pulsating flow was generated by a motor-driven cylinder head fitted with a variable valve actuation system. Different levels of turbocharger rotational speed and different intake valve opening strategies were considered. For each operating condition compressor unsteady performance was evaluated starting from measurement of several instantaneous parameters (inlet and outlet static pressure, mass flow rate and turbocharger rotational speed). A significant deviation of compressor instantaneous performance from steady state was observed, resulting in a hysteresis loop surrounding the steady state curve.
Experimental Thermal and Fluid Science, 2014
To make simulation models able to accurately predict engine performance, a better understanding o... more To make simulation models able to accurately predict engine performance, a better understanding of compressor behavior over an extended range can be accomplished by using a specialized test facility and measuring equipment. Besides, the correct surge line position is another important aspect to be considered to optimize engine-turbocharger matching calculation. In the paper the results of an experimental investigation developed on a turbocharger compressor for heavy duty vehicle application is presented. The study was focused on the definition of surge line position adopting different methods and on the evaluation of compressor performance over an extended range, taking into account compressor behavior both in the stable and unstable operating region.
Applied Energy, 2013
ABSTRACT An experimental and theoretical investigation is being performed to evaluate exhaust emi... more ABSTRACT An experimental and theoretical investigation is being performed to evaluate exhaust emissions and fuel consumption of Heavy Duty Vehicles (HDVs) circulating in urban areas and involved in commercial shipping activities. The study is focused on the city of Genoa, whose urban road network is influenced by highway connections and shipping activities, as seven motorway exits and more than twenty accesses to port area are located within the urban area. In a first step, the HDV flows crossing highway exits, urban zones and port areas were evaluated, as well as the relevant vehicle classes. The typical urban trips linking highway exits to port gates and the HDV mission profiles within the port area were then defined, whose validation was performed through an experimental campaign for HDV instantaneous speed measurements on urban trips and in port zones. The availability of speed patterns enabled the application of Passenger Car and Heavy Duty Emission Model (PHEM) for the estimation of fuel consumption and emission factors for selected HDV classes. The main results of the different investigation steps are presented and discussed in the paper, outlining the specific activities of HDVs in port area and the relevant emissive behaviour.
SAE Technical Paper Series, 2005
ABSTRACT The paper presents the main results of a study focused on the definition of exhaust emis... more ABSTRACT The paper presents the main results of a study focused on the definition of exhaust emission factors for a waste collection vehicles fleet, taking into account the specific emission profiles. As a first step, on the basis of the fleet characteristics, different classification criteria were applied, aiming at the identification of suitable vehicle classes. Then, the calculation of the exhaust emissions for each class was based on a two terms equation, the first related to the vehicle travel (considering different sources for the relevant emission factors) and the second to the equipment use, whose contribution is estimated on the basis of different parameters. A computational code was then set up for the evaluation of the daily emission of normalised pollutants for the whole fleet and each required service. The results of different calculations are presented in the paper, referring to the distribution of total emissions between the different vehicles categories and classes, the estimation of the waste fleet contribution to the overall pollution due to road transport in Genoa urban area and the effects of the fleet renewal.
L’attività oggetto del presente lavoro rientra nell’indagine finalizzata allo studio delle emissi... more L’attività oggetto del presente lavoro rientra nell’indagine finalizzata allo studio delle emissioni dei motocicli, congiuntamente sviluppata dall’Istituto Motori del CNR e dall’Internal Combustion Engines Group operante presso il Dipartimento di Macchine, Sistemi Energetici e Trasporti dell’Università di Genova. Due scooter 4T, omologati secondo la normativa Euro 3 per le emissioni allo scarico, sono stati testati su banco a rulli con diversi cicli di guida, sia di omologazione che reali, al fine di stimarne i fattori di emissione (con riferimento a CO, HC, NOx e CO2) ed il consumo di combustibile sia in condizioni di funzionamento a caldo (motore e fluidi regimati termicamente) che con partenza a freddo. Nel lavoro viene analizzata l’influenza dei cicli considerati sui fattori misurati e sul comportamento a freddo dei veicoli analizzati, in termini di sovraemissioni, durata del transitorio e relativa distanza percorsa ed effettuato un confronto dei dati sperimentali con quelli app...
A computer PROGramme for Road vehicles EmiSSions evaluation (PROGRESS) was developed in order to ... more A computer PROGramme for Road vehicles EmiSSions evaluation (PROGRESS) was developed in order to assess the environmental impact from road traffic under real urban driving conditions. The procedure takes into account different aspects, i.e., the estimation of circulating fleet and the relevant urban driving statistics, the definition of typical urban trips and the evaluation of emission factors from road vehicles in urban environment. In the present release, PROGRESS allows to calculate the total mass of normalised pollutants at the exhaust of eight different vehicles categories, referring to the whole urban area (or part of it) and to different periods of time (ranging from one hour to one year). In the paper the main characteristics of the PROGRESS code are presented, with reference to its structure, to the calculation procedure of hot, cold and total emissions and to the outputs. Finally an application is presented and discussed, referring to the city of Genoa.
International Journal of Environmental Studies
ABSTRACT A simulation tool was developed to evaluate variations in exhaust emissions from cars wh... more ABSTRACT A simulation tool was developed to evaluate variations in exhaust emissions from cars when replacing conventional powertrains with electric or hybrid propulsion systems. The model permits calculation of direct emissions (released at the vehicles’ exhaust) and indirect emissions (released when producing electricity for batteries recharging). To verify model outputs, a reference scenario was defined selecting the urban area of Genoa, Italy, considering the number of vehicles and mileage of eight vehicle categories. A simulated scenario was then designed, replacing cars belonging to older legally defined classes with electric and hybrid ones. Significant reductions were estimated for regulated pollutants, with higher benefits estimated for CO and NOX emissions, deriving from calculated reductions and contributions of cars in the reference scenario. No advantages were estimated for CO2, outlining that a change in the national mix for electricity production is also required.
Cogent Engineering
The influence of rail pressure control on fuel consumption, emissions and combustion in an automo... more The influence of rail pressure control on fuel consumption, emissions and combustion in an automotive downsized turbocharged diesel engine was investigated, considering different operating modes in three-part load working conditions. These modes were selected according to the results of a previous step of the study, where low NO X and fuel consumption levels were obtained managing a hybrid exhaust gas recirculation (EGR) system and the turbocharger variable nozzle turbine (VNT). Aiming at limiting observed soot penalties, increased values of rail pressure were applied, deepening the interactions with engine-controlled sub-assemblies and the related variations in operating, environmental, energy and combustion parameters. At low levels of engine speed and load, major reduction in NO X emissions and fuel consumption were observed, with acceptable soot and noise combustion increase, while turbocharger speed was also enhanced. No variations in fuel consumption were achieved at higher load and speed, while soot penalty remained significant. A simplified method to describe and model engine behaviour and combustion process was also developed, defining linear relationships between rail pressure and engine quantities, including a wide set of combustion parameters derived from in-cylinder pressure diagrams and heat release curves.