Fernando Ortenzi is a mechanical engineer and Ph.D in energetics. Works as a research fellow at DITS (from 2004 to 2008) and now at CTL (Centre for Transport and Logistics) , Sapienza universitĂ of Rome (Italy). Research interests: the measurement of energy and environmental impact of vehicles and the development of tools to collect data from the electronic system of vehicles and trucks for emission modeling and fleet management. Has also worked on experimental test of vehicle fuelled with blends of methane and hydrogen working on the tuning of the engine.
Abstract: The promise of reducing harmful and CO2 emissions by focusing on hydrogen-methane blends (HCNG) have recently attracted the interest of vehicle manufacturers and transport operators. Several experiments have been conducted in laboratory facilities to assess the potential of HCNG blends in order to decrease the exhaust emissions. This paper reports the results of experimental tests performed at the ENEA Casaccia Research Center aiming to evaluate the energy and environmental performances of a CNG vehicle when fuelled with a hydrogen-methane blend. Two buses for urban transit service were fuelled with HCNG blends with different percentage of hydrogen (5%, 10% ,15% 20% and 25% of hydrogen by volume). A 100% methane gas was used as reference to compare the advantages and disadvantages that can be derived from the use of HCNG blends. Road tests have been carried out by running fixed tracks, which are representative of urban and suburban driving cycles. Vehicles were powered with a lean burn engine whose setup - based on ignition advance angle, has been tuned for controlling the NOx emissions. CO2 emissions have been investigated to evaluate the leverage effect based on an increased CO2 reduction resulting from an increased engine efficiency.
Abstract: Introduction Hybrid technology is seen by many as a potential solution to reduce vehicle emissions in cities. However type approval tests of hybrid vehicles measure emission levels comparable to those of conventional cars in the same market segment. It has been argued that type approval tests do not represent the reality of emission in cities therefore, to quantify the real emission of hybrids and to compare them with those of conventional vehicles in the same conditions, an emission measurement campaign was organised.
Acquisition campaign Three Honda cars, one conventional (the Civic 2.0) and two hybrids (the Civic IMA and the Civic Hybrid), equipped to collect emissions as well as the engine and vehicle working parameters were driven three times by twenty drivers on the same urban route. Drivers were asked to drive normally and not requested to do anything special but to scrupulously follow the given itinerary.
Results Two main results were obtained: average and maximum emission levels for the three cars are quantified; the effects of the drivers on such levels assessed. The conventional car (with two people and 250 kg of measurement tools onboard) consumes an average of 12.6 l/100 km, its CO2 emissions range between 200 g/km and 300 g/km with an average of 260 g/km. CO emissions range between 0.25 g/km and 6.25 g/km (Euro IV limit is 1 g/km) with an average of 2 g/km. The most recent of the two tested hybrids consume in average 8.23 l/100 km and emits between 150 and 230 g/km of CO2 with an average of about 180 g/km; it emits virtually no CO in the majority of cases but can reach up to 1.8 g/km and average CO emissions are about 0.2 g/km. The hybrid performs always better than the conventional; in terms of CO2 and consumption it can have up to a 30% reduction and in terms of CO up to 90% reduction.
Conclusions The wideness of the measured ranges depends mostly on the drivers. Women tend to consume and emit less than men. The reason for this is the different way they use the accelerator pedal; they push it less and keep it steadier. In other word the standard deviation of the accelerator position (or throttle) is lower. It is here shown how a correlation exist between the throttle standard deviation and the emissions which justify using such parameter as the indicator of drive-style.
Abstract: While the use of hydrogen in fuel cell vehicles will be the ultimate target for sustainable mobility, much attention has to be devoted to a suitable “bridge technology”, to accelerate the process of the introduction of these new technologies and in the meantime to build an infrastructure suitable for the utilisation of hydrogen. In the short-medium term, the atmospheric emissions could be significantly reduced by using different percentages of hydrogen mixed with natural gas in internal combustion engines.
The paper is based on the results of an experimental test campaign carried on in ENEA labs, aimed at identifying the prospective of the use of blends of natural gas and hydrogen (HCNG) in existing ICE vehicles. The tested vehicle is an IVECO Daily CNG, originally fuelled with natural gas and the tests had been made on the ECE15 driving cycle comparing the emission levels of the original configuration (CNG) with the results obtained with different blends (percentage of hydrogen in the fuel) and control strategies (stoichiometric or lean burn).
Abstract: The power supply, fuel consumption, and noxious emissions of a vehicle depend on the use that is made of it. Usually [1] only the driving cycle is considered to be a sufficient way to gauge a vehicle's usage. It is not, however, enough. Experimental tests have proved that, while similar driving cycles entail similar power demand, fuel consumption and emissions differ. In addition, a driving cycle, usually a synthesis [1-7] of several cycles collected experimentally, represents neither a specific link of the road network nor a specific user. Vehicle use must, accordingly, be described by something more comprehensive than the driving cycle, and this might be called the â€use cycle’, for which a definition needed to be found. For a definition of the use cycle, all possible factors influencing vehicle emissions had to be examined. It was thus necessary to develop a tool both for gathering data that might reveal a different use of the vehicle and for identifying factors that might have an influence on emissions. The easiest, cheapest, and most versatile way to collect real data on the use of a vehicle is to use the vehicle's own sensors connected to the on-board diagnostic (OBD-2) port. Readings from a GPS can provide some characteristics related to the vehicle's position. This paper describes the development of a tool for collecting real-time OBD and GPS information. The acquisition tool was validated by a number of tests on a dynamometer chassis and differences are never higher than 3 per cent (e.g. on speed max 2 km/h). The first result obtained on vehicle usage is that driver behaviour influences throttle position independently of the driving cycle. Even with similar driving cycles, the accelerator pedal position and its variations turned out to be heavily different, suggesting a new definition of driver behaviour linked to the way the driver uses the pedals. Such pedal movement does have an influence on the air-fuel ratio, which remains stable around the stoichiometric value with â€calm’ use of the accelerator, while it changes continuously, never becoming stoichiometric, with â€aggressive’ accelerator behaviour. The continuous use of the developed tool on large fleets of vehicles will allow progress along this path and help define use cycles that may then be used by car manufacturers to design vehicles more efficient in their different uses and by the authorities to force more stringent homologation rules.
Abstract: La possibilità di ridurre le emissioni nocive e di CO2, utilizzando le miscele idrogeno-metano (HCNG) ha recentemente attratto l'interesse di produttori di veicoli e operatori del trasporto. Per valutare le potenzialità delle miscele al fine di diminuire le emissioni allo scarico dei motori a combustione interna sono stati condotti diversi esperimenti. Questo lavoro riporta i risultati di prove sperimentali, eseguiti presso il centro ENEA Casaccia, al fine di valutare le prestazioni energetiche ed ambientali di due autobus a (BredaMenarini Vivacity CNG rispettivamente di 8 e 12 m di lunghezza) testati con diverse miscele di metano idrogeno con 5%, 10%, 15%, 20% e 25% di idrogeno in volume utilizzando come riferimento per i test prove effettuate con un gas metano del 100%. Le prove su strada sono state effettuate eseguendo un percorso prefissato, rappresentativo di cicli di guida urbani ed extraurbani e, per la messa a punto del motore termico è stata modificata la mappatura dell’anticipo motore per adattarsi alle variate caratteristiche del combustibile, (minimizzazione dei consumi e non aumento delle emissioni). I bus, quando alimentati con idrometano, grazie ad una maggiore velocità di combustione dell’idrogeno mostrano un miglioramento del rendimento energetico e i miglioramenti sono visibili già con basse percentuali: con un contenuto del 5% di H2 è stato evidenziato un miglioramento di circa il 4% del consumo energetico mentre i miglioramenti massimi si ottengono con una miscela dal 15% al 25%. I test effettuati hanno evidenziato una riduzione di CO2 che è maggiore rispetto a quella calcolabile con la sola sostituzione degli atomi di carbonio con l’idrogeno. Si verifica infatti un effetto leva che porta ad avere per una miscela del 25% diH2 una riduzione del 25% le emissioni di CO2 rispetto al 9% del valore teorico previsto, e questa è la più grande riduzione rilevata nella sperimentazione. CO ed HC hanno valori molto bassi al limite di sensibilità dello strumento di misura utilizzato (HORIBA OBS 1300), mentre gli NOX fino a una miscela del 15% risultavano più bassi rispetto alla configurazione metano al 100%, ma per miscele con maggiore presenza di idrogeno aumentano.
Abstract: The actual type approval procedure of vehicles, based on a fixed driving cycle for all the vehicles (NEDC), is not representative of their real on-road usage: the driving style and its influence on consumption and emissions cannot be neglected. The on road impact of vehicles on their real use is not known and it is difficult to measure (the PEMS are expensive, have big volume and mass and need continuous maintenance); the objective of this work is to develop a methodology to calculate in real time the energy and environmental impact of spark ignition vehicles, using the onboard sensors of the vehicle and emissions models to calculate them.
An onboard instrumentation able to communicate with the electronic system of the vehicle (OBD/CAN) was developed to collect all the sensor data installed on a vehicle: those values are used as input values to the emissions models of CO2, CO, HC and NOx developed in the present work. The CO2 and CO have been calculated using a chemical equilibrium combustion model with 6 combustion products, with the equilibrium temperature used as a calibration constant. HC and NOx, produced during transients, are assumed to be dependent from the accelerator pedal gradient, but during engine cold start also from the catalyst temperature.
To validate the models, a spark ignition hybrid vehicle, the Honda Civic Hybrid has been tested on a chassis dynamometer running the three Artemis driving cycles. The emissions have been measured with the CVS (taken as reference) and with a portable emission analyzer, (Horiba OBS 1300), used for comparison with the models. The results shows that the values calculated by the models are comparable with those measured by OBS, but for HC and NOx are better because the OBS gave inaccuracies due to its high minimum resolution.
Abstract: The HOST project developed concept and prototype for an innovative low polluting modular transport mean suitable for the urban transport of people and goods. Main HOST commercial innovation is to use one vehicle for four different transport service in the 24 hours thus lowering the extra-cost of having a low polluting vehicle. HOST has been dimensioned to supply four different urban transport services: nocturne collective taxi, daytime car sharing, daytime freight collection and distribution and nocturne garbage collection. The user acceptance, energy and environmental and financial evaluation are reported in this paper.
The user acceptance evaluation showed that HOST characteristics (transshipment capabilities, enhanced maneuverability and environmental concern) are interesting, but issues as the technological complexity and lack of infrastructures have to be resolved.
The powertrain, a hybrid series, has considerably lower emissions levels than conventional vehicles while consumption is comparable for all the services but car-sharing in which HOST consumes more due to its higher weight.
The financial evaluation shows that at the moment, to build the HOST powertrain, about 165 000 € are needed and a complete vehicle with also the cabin could cost about 290 000 €. To be financially competitive, the global cost of HOST should be between 220 000 and 230 000 €; 60 000€ less than the cost of the prototype.
Abstract: European Type approval procedure defines a synthetic driving cycle (the NEDC) over which one vehicle per type has to be tested. Euro 1, 2, 3, 4 and 5 differ (beside vehicle preconditioning and warm-up procedures introduced since Euro 3) only because limits for the different pollutants have been progressively lowered.
This paper analyses through a number of experimental tests on spark-ignition cars, a hybrid and a conventional vehicle, the driving conditions responsible for most of the emissions and assesses how such conditions are reproduced by the type approval test.
The engine conditions mostly responsible for emissions are: warm-up phase, full loads and transients. Only the warm-up is well covered by the NEDC for vehicles with more than 35 kW/ton power-weight ratio.
Tests performed with the Honda Hybrid (the low environmental impact vehicle) and with the Alfa Romeo 147 1.6 (the conventional vehicle) showed how on the NEDC most emissions are produced in the warm up phase and are of the same order of magnitude for both cars while on more realistic driving cycles (ARTEMIS cycles have been used here) the capacity of the Hybrid to mitigate the transients effects results in a much lower emission rate. Full load conditions are not kept under control by the Hybrid as by the conventional vehicle when the O2 exhaust sensor is disabled and the air-fuel ratio is no more stoichiometric.
Even though this paper has not tested all possible vehicles types, it shows that European type approval procedure has some weaknesses in accounting for the main causes of vehicle emissions. Any new procedure addressing better transients and full load conditions would help the diffusion of low emission vehicles like hybrids more than progressively lowering the allowed emission thresholds on current type approval procedure.
Abstract: La quantificazione degli effettivi consumi ed emissioni dei veicoli stradali non è semplice. I metodi esistenti presentano diversi limiti e la rilevazione su cicli NEDC, in vigore in Europa per l’omologazione, tende a sottostimare i valori caratteristici dell’uso su strada. La conoscenza delle reali emissioni consentirebbe una tassazione penalizzante per i veicoli effettivamente più inquinanti, incentivando la diffusione di mezzi a contenuto impatto ambientale.
L’esigenza di caratterizzare il funzionamento del veicolo su strada, in modo semplice ed economico e con sufficiente accuratezza, ha indirizzato lo sviluppo di un innovativo metodo. Questo impiega modelli fisico/matematici basati su alcuni dei parametri motoristici (carico motore, portata d’aria aspirata, rapporto aria/combustibile, ecc) prelevati con adeguata strumentazione dal sistema elettronico di controllo e diagnosi del veicolo (EOBD), imposto nei veicoli moderni dalla direttiva 98/69 CE.
Il metodo, sviluppato e validato per un veicolo Diesel (FIAT 500 1.3 Multijet Euro V), stima i consumi (e CO2) e le emissioni degli NOx. Il modello dei consumi calcola la portata di combustibile iniettata come rapporto tra la portata d’aria aspirata (fornita dai sensori di bordo) ed il rapporto aria/combustibile, non rilevato dal sistema elettronico ma caratterizzato da una dipendenza di tipo potenza dal carico motore. Gli NOx sono quantificati utilizzando la concentrazione volumica degli stessi nei gas di scarico (non fornita dai sensori di bordo) per la quale si è individuata una relazione esponenziale col carico motore.
Il metodo è stato validato con prove sulla FIAT 500 al banco a rulli (cicli di marcia UDC e Artemis e prove a regime fortemente variabile) e su strada. I consumi sono confrontati con quelli rilevati dal sistema elettronico del veicolo e gli NOx con quelli misurati dagli analizzatori Horiba OBS 1300 e AVL AMA 4000 e da un CVS. L’attività svolta ha evidenziato una generale buona accuratezza del metodo.
Abstract: Il trasporto stradale è uno dei principali responsabili dell’inquinamento ambientale. Tra i fattori che determinano l’impatto ambientale di un veicolo lo stile di guida del conducente è uno dei più rilevanti e le differenze di impatto ambientale tra guidatori, a parità di veicolo, non sono trascurabili. In questo lavoro si è valutato l’impatto energetico - ambientale (consumo di carburante ed emissioni di CO2, NOx, CO e HC) dello stile di guida EcoDriving su una vettura diesel, in ambito urbano, nel suo reale uso su strada. In particolare si è utilizzata una FIAT 500 1.3 mJet.
I risultati ottenuti sono i seguenti: diminuzione del 13.6% del consumo di carburante (da 5.62 a 4.86 l/100 km) e delle emissioni di CO2 (da 148 a 128 g/km), diminuzione del 4.2% delle emissioni di NOx (da 0.376 a 0.360 g/km), emissioni di CO e di HC del tutto trascurabili (sempre comprese tra gli 0.001 e gli 0.01 g/km in tutte le condizioni di funzionamento).
Per quanto riguarda le emissioni di NOx è opportuno sottolineare che, seppure il risultato complessivo del test in termini di g/km emessi sia positivo, si sono evidenziate delle situazioni particolari all’interno dei test effettuati su strada in cui le emissioni di NOx sono risultate superiori adottando lo stile di guida EcoDriving rispetto a quelle ottenute adottando lo stile di guida di uno degli Autori (preso come riferimento per i test svolti). In particolare sono state individuate delle accelerazioni da fermo fino ai 55 km/h circa (situazioni tipiche in ambito urbano) in cui si è registrato un aumento delle emissioni di NOx di quasi il 34% effettuando tali accelerazioni con lo stile di guida EcoDriving. Dall’analisi svolta è emerso che è la frequenza dell’incorrere di tali accelerazioni all’interno del ciclo di marcia che può causare l’aumento globale (in g/km sul totale di un ciclo di marcia) delle emissioni di NOx adottando lo stile di guida EcoDriving in ambito urbano con una vettura diesel.
Abstract: Hybrids are seen as a potential solution to urban traffic pollution and energy consumption; however studies show how pollution economic appraisal is one order of magnitude lower than fuel cost putting all the burden of the economic success the hybrid capability of reducing fuel consumption.
Two Honda Civic Hybrid of the Italian Ministry of Environment fleet were constantly monitored while driven one each by the calmest and by the most aggressive of the Ministry drivers to assess driver effects on air pollutant emissions.
Measurements have shown how the aggressive driver emits 10 times more VOC, and 4 times more CO and NOx than the calm driver while consuming 35% more fuel. In the economic appraisal over the expected 14 years vehicle life however the aggressive driver costs 16 300 € while the aggressive one 22 500 € only 38% more. This is due to the extremely low cost of emissions (excluding CO2) which is 160 € for the calm driver and 610 € for the aggressive one for the entire life of the vehicle.
Unless pollutants are monetized according to the position where they are “left” in the atmosphere there is no way emission differences between cars and drivers can be reflected in any economic appraisal.
Abstract: Il trasporto stradale è uno dei principali responsabili dell’inquinamento ambientale. Le attuali normative in materia di emissioni dei veicoli stabiliscono un ciclo di marcia che il veicolo deve eseguire in fase di omologazione e i limiti massimi di emissioni che il veicolo può produrre su tale ciclo. Tale procedura non è rappresentativa del reale utilizzo che dei veicoli viene fatto in strada. Un ciclo di marcia standardizzato, ed uguale per tutti, non consente di tener conto dello stile di guida e le differenze di impatto ambientale tra guidatori a parità di veicolo non sono trascurabili.
I veicoli ibridi, che cominciano ormai ad essere una realtà prodotta su grande scala, sono una delle tecnologie promettenti per ridurre l’impatto ambientale causato dal trasporto stradale, ma anche essi non sono immuni dall’influenza dello stile di guida.
Questo articolo dimostra come diversi veicoli e diversi guidatori su uno stesso percorso possano produrre livelli di emissioni molto diversi, anche di diversi ordini di grandezza. L’impatto dei guidatori, che può essere molto elevato su veicoli convenzionali viene ridotto, ma non eliminato, dai veicoli ibridi grazie al supporto del sottosistema elettrico, che aiuta il motore termico in fase di accelerazione e recupera energia durante le fasi di rilascio e frenatura.
In questo articolo si caratterizza lo stile di guida tramite l’uso che il guidatore fa del pedale dell’acceleratore. La deviazione standard della posizione del pedale mostra un’elevata correlazioni con consumi ed emissioni. Uno stile di guida calmo, che tende a mantenere costante il pedale dell’acceleratore risulta meno emissivo e le donne, che hanno tendenzialmente deviazioni standard più basse, risulta producano livelli di emissioni inferiori.
Abstract: La politica per la riduzione dell’inquinamento ambientale dei trasporti prevede l’utilizzo di idrogeno per le favorevoli caratteristiche di efficienza di conversione energetica e le relative emissioni. Nonostante l’impiego più efficiente e pulito preveda l’utilizzo di idrogeno puro in celle a combustibile, l’elevato costo di tecnologie ancora non mature e parallelamente la necessità di disporre di infrastrutture per la produzione, lo stoccaggio e la distribuzione dell’idrogeno, relegano questo tipo di implementazione ad una visione a lungo termine. Sono pertanto previsti degli scenari a breve-medio termine che permettano di sperimentare concept innovativi abbinati a tecnologie di consolidata affidabilità e costo ridotto. L’introduzione di una limitata quantità di idrogeno in motori a combustione interna originariamente concepiti per l’alimentazione a gas naturale, può rappresentare in questo contesto una soluzione per l’introduzione del vettore idrogeno nel contesto cittadino, finalizzata a promuovere l’installazione di apposite infrastrutture di produzione, stoccaggio e distribuzione. La sostituzione di una piccola percentuale (5-30% in volume) di gas naturale con idrogeno consente di ottenere un processo di combustione più efficiente e veloce, e pertanto minori emissioni di HC, CO e CO2 ed un aumento degli NOX, potenzialmente contenibile attraverso una strategia di regolazione a carica magra.
Nel contesto del progetto Europeo BONG-HY (Blends Of Natural Gas – HYdrogen), è stata portata avanti una campagna di test su un veicolo commerciale alimentato a gas naturale presso il Centro Ricerche La Casaccia (ENEA). L’obiettivo principale del progetto, che coinvolge diversi partner (ASM BRESCIA e Università Cattolica di Brescia, Università di Roma “La Sapienza” e “Tor Vergata”), consiste nell’analisi ed implementazione di strategie di controllo del motore a carica magra per la contemporanea riduzione delle emissioni di CO2 ed ottimizzazione delle emissioni delle specie inquinanti regolamentate, in particolare degli NOX.
Nella presente memoria pertanto si illustrano i principali risultati ottenuti in questo contesto. Dato che la variazione delle prestazioni del motore dipende fortemente dalle modalità di evoluzione del processo di combustione, si è optato per un approccio misto numerico-sperimentale. In particolare, la termofluidodinamica all’interno della camera di combustione è stata studiata mediante un modello 3D perchè caratterizzato da elevato grado di dettaglio, e notevole affidabilità predittiva. Il modello motore è stato implementato nel contesto del codice KIVA-3V, opportunamente modificato, specialmente per quanto riguarda la rappresentazione del processo di combustione turbolenta basata su un modello flamelet (CFM, Coherent Flame Model) riformulato per l’applicazione a miscele di combustibili.
L’applicazione del modello ha consentito di individuare l’effetto della variazione dei parametri di controllo del motore (principalmente l’anticipo all’accensione) a supporto delle attività sperimentali, consentendo, come atteso, una riduzione delle emissioni di CO2 accompagnato da emissioni di NOX sostanzialmente invariate.
Abstract: Main drivers for the introduction of hydrogen as a fuel for vehicles are the reduction of both greenhouse gases emissions and local pollutants, above all in congested urban environments.
While the use of hydrogen in fuel cell vehicles will be the ultimate target for sustainable mobility, much attention has to be devoted to a suitable “bridge technology”, to accelerate the process of the introduction of these new technologies and in the meantime to build an infrastructure suitable for the utilization of hydrogen. In the short-medium term, the atmospheric emissions could be significantly reduced by using different percentages of hydrogen mixed with natural gas in internal combustion engines.
The paper is based on the results of an experimental test campaign carried on in ENEA labs, aimed at identifying the prospective of the use of blends of natural gas and hydrogen (HCNG) in existing ICE vehicles. The tested vehicle is a Iveco Daily CNG, originally fuelled with natural gas and the tests had been made on the ECE15 driving cycle comparing the emission levels of the original configuration (CNG) with the results obtained with different blends (percentage of hydrogen in the fuel) and control strategies (stoichiometric or lean-burn). Also the steady results, that were used for tuning the engine from CNG to HCNG are reported.
Abstract: Passenger vehicles are one of the most significant source of pollution in the cities. The emissions production of a vehicle is strictly dependent on how the vehicle is used. This paper has the objective to characterize a Euro IV vehicle so to understand in depth the behavior in its real usage on road in terms of fuel consumption and emissions.
An Honda Civic 2.0 Euro4 vehicle has been tested and the experimental results are reported.
The experiments have been carried out by means of two tools: a OBD2 interface to connect a laptop PC to the vehicle for collecting engine parameters (Alessandrini et al. 2006) and the HORIBA OBS1300 equipment to measure CO, NOx, HC emissions and the exhaust gas flow, pressure and temperature.
Three types of experimental tests have been made: a set of them on a dynamometer chassis and a part on road.
The warm-up phase, as foreseeable, is the main source of HC (up to 550 ppm) and CO (up to 10 %Vol), while in steady conditions the emissions are often too low to be appreciated by the sensors. At full open throttle, the air-fuel ratio is no more stoichiometric, correspondingly the highest measured values of CO and NOx are encountered, being the first significantly influenced by this parameter while the NOx mostly by high combustion temperatures.
Under transient conditions, typical of urban cycles, the peak values for CO are 2.6%Vol and 500 ppm for NOx, mainly due to the enrichment of the air-fuel mixture; the engine ECU (Electronic Control Unit) has a delay in counteracting the correct quantity of fuel to be injected and the mixture is purposefully enriched to give better engine performances in such critical moments. The HC are always negligible.
The driver behavior as well has an important impact on the emissions and the accelerator pedal usage (and its temporal derivative) is the most relevant factor that influences fuel consumption and emissions.
Several drivers have been engaged and the behavior analyzed shows how the vehicle maintains its Euro4 characteristics if never driven at full throttle regime. Transient conditions and in particular severe accelerations are the worst conditions concerning consumption and emissions
Abstract: Hydrogen-enriched combustion has been studied by several institutions and companies over the last three decades. The purpose of adding hydrogen to conventional fuels is to extend the lean limit of combustion because hydrogen improves flame stability and allows a lower temperature combustion. Even with stoichiometric mixture, HCNG advantages had been demonstrated, since blends determine a reduction of noxious emissions. In the framework of an EU project called BONG-HY, bench tests with HCNG on a natural gas vehicle had been carried on at ENEA. Results of lab tests showed a fair improvement of the efficiency and CO2 emissions as well as an overall improvement regarding local pollutants.
Abstract: Freight distribution in cities is mostly done by road and is responsible for 30 to 40% of the energy consumed by transport and these percentages grow when certain pollutant, such as PM, are considered. City logistics is mostly organised on a private basis and each logistics operator has its own clients, vehicles and storage areas. No cooperation exists between operators to rationalise the distribution trips. Urban penetration of freight by rail is scarce and inner-city rail road terminals, wherever there were any, are being dismissed because the increasing cost of inner city land is making more convenient to sell land inside the cities and to make new terminals outside of them. Consequently urban freight distribution by heavy duty vehicles is becoming more and more common.
In this framework a joint research team of ENEA (the Italian national energy and environmental research agency) and CTL (the recently started excellence centre on freight transport and logistics) organised several acquisition campaigns to monitor the present situation of city logistics in Rome under many aspects including energy consumption and environmental impact with the aim of defining strategies and tools to make it more sustainable. The acquisition campaigns were made collecting in real time a number of parameters from the vehicles distributing goods to supermarkets in Rome either fresh food from the new “fruit and vegetable gross market” 2 km east (Guidonia) of the outer road ring of Rome (GRA) and from a logistic platform 15 km south (Pomezia-Santa Palomba) of GRA or other goods from one of the few remaining inner city rail terminals (San Lorenzo). Such campaigns showed how size and power of the presently used vehicles are dimensioned on the “outer city” leg of the trip because inside the city much smaller and less powerful vehicles can be employed. It would be therefore possible, if city logistics were re-organised, to employ hybrid vehicles. In details a 9 kW generator series hybrid can easily substitute a 120 kW conventional vehicle.
The approach to make city logistics more sustainable must definitely be an integrated technological and regulatory approach. Under the vehicle technology point of view hybrids have either to be dimensioned for outer-city trips, like the dual mode Microvett Daily or the regulatory framework should promote the introduction of logistic platforms inside the urban ring in which case electric vehicles either pure or hybridised with small size generator or FC, (5-10 kW), like the MicroVett Neo FCHV, could have a real chance as proven by another Microvet experience in the city of Vicenza.
Abstract: Tra i fattori che determinano l’impatto ambientale di un veicolo lo stile di guida del conducente è uno dei più rilevanti e le differenze di impatto ambientale tra guidatori, a parità di veicolo, non sono trascurabili. Negli ultimi due decenni è stato sviluppato uno stile di guida, Ecodriving, che garantisce la massima efficienza alla guida. L’attenzione internazionale nei confronti di questo semplice metodo per ridurre le emissioni di CO2 del trasporto stradale è crescente. Per quantificare in maniera sistematica l’influenza del guidatore sul consumo di carburante il CTL ha sviluppato un algoritmo che, a partire da dati reali di viaggio, permette di calcolare il consumo ideale minimo che si sarebbe potuto ottenere a parità di veicolo, percorso e traffico adottando lo stile di guida Ecodriving. É stata quindi organizzata una grossa campagna di monitoraggio (10 veicoli, 270 conducenti, 120.000 km) per quantificare i benefici ottenibili in termini di riduzione del consumo di carburante e delle emissioni di CO2. I risultati mostrano riduzioni ottenibili delle emissioni di CO2 fino a 40-60 g/km fino a circa 60-80 km/h di velocità media di tratta, oltre la quale, invece, l’influenza del conducente diventa minore.
Abstract: Nell’ambito del progetto PEGASUS, un progetto di innovazione industriale per la mobilità sostenibile che fa capo al programma INDUSTRIA 2015, è stata eseguita una campagna di acquisizione su strada per il monitoraggio dell’impatto energetico ambientale di 10 veicoli, 4 del servizio Car-Sharing di Roma e 6 del Car Rental di AVIS.
Tali veicoli sono stati monitorati da marzo a novembre 2010 con una strumentazione di bordo in grado di acquisire i parametri motoristici dal sistema elettronico del veicolo (OBD/CAN).
I risultati mostrano come i veicoli, nel loro reale utilizzo su strada hanno livelli emissivi molto diversi da quanto stabilito in fase di omologazione e a parità di veicolo, i guidatori hanno un grande impatto sulle emissioni. Come esempio si riportano i valori di emissioni dei veicoli a benzina (4 veicoli) monitorati: NOX da 0.1 a 0.2 g/km (limite EURO V 0.06 g/km), CO da 0.6 a 1.14 (1 g/km) HC 0.03 a 0.045 (0.075).
Per quanto riguarda i diesel invece si riportano i valori di NOX che variano da 0.5 a 1.4 g/km (limite EURO V:0.2 g/km).
Abstract: Driving style is one of the most significant factors in the environmental impact of a vehicle. Over the past two decades a new driving style, Ecodriving, has been developed to guarantee maximum driving efficiency. The basic rules of Ecodriving were established by European project ECODRIVEN.
Over the years some studies , have shown an average reduction in fuel consumption of 10% to 15% when Ecodriving is adopted. These studies (including those by CTL ) evaluated the efficiency of Ecodriving by analysing driving behaviour before and after Ecodriving training or else evaluated differences in driving style among different drivers or Ecodriving efficiency with fixed driving cycle on a chassis dynamometer1. Fuel consumption depends on many factors, including average speed, route type, traffic, and Ecodriving proficiency. The main limitation of these studies is that they are unable to distinguish the influence of traffic level on fuel consumption from that of driving style. This limitation suggested the need to develop a new system for assessing the energy and environmental impact of Ecodriving and, more generally, the influence of the driver on vehicle fuel consumption.
CTL has developed an algorithm to quantify the influence of the driving style on fuel consumption, comparing driver behaviour with that of an ideal driver following the Ecodriving rules. It is called the Ecoindex. The algorithm modifies the original driving cycle by applying the Ecodriving rules and preserving all the constraints of the route (average speed, number and duration of stops, etc.) so that the two driving cycles, the real and the calculated, differ only for the driving style adopted. The modified cycle is characterised by the minimum fuel consumption that could be obtained with the same vehicle, on the same route, and with the same traffic level by adopting Ecodriving rules. The ratio between the minimum and the real fuel consumption is the Ecoindex that correlates the driver’s driving style with fuel consumption. The Ecoindex can be interpreted as the minimum fuel required ideally in comparison with the actual fuel consumed.
The algorithm has been applied on a monitoring campaign of 10 vehicles to evaluate the influence of drivers on fuel consumption and environmental impact. Vehicles were monitored from March to November 2010 for a total of 120,000 km and with 278 different drivers.
The results, aggregated by routes, show a high variability in fuel consumption for the same route average speed. This variability decreases with the increase of the route average speed. The minimum fuel consumption (and then CO2) was calculated for each route and possible reductions in terms of CO2 can be up to 40–60 g/km for route average speeds up to about 60–80 km/h. Beyond this threshold the influence of the driver on fuel consumption diminishes.
