In this article, the aptitude of natural gas as feedstock in steam reforming process for hydrogen production is compared with that of different liquid fuels （pure compounds and commercial fuels）, with the aim to inv...In this article, the aptitude of natural gas as feedstock in steam reforming process for hydrogen production is compared with that of different liquid fuels （pure compounds and commercial fuels）, with the aim to investigate the potentialities of biofuels to overcome the CO2 emission problems deriving from fossil fuel processing. The performances of a nickel based catalyst （commercially used in steam reforming of natural gas） were evaluated in terms of feed conversion and yield to the different products as function of temperature, space velocity and water/fuel ratio. Furthermore, a preliminary evaluation of catalyst durability was effected by monitoring yield to H2 versus time on stream and measuring coke formation at the end of experimental tests. High yields to hydrogen were obtained with all fuels investigated, whereas the deactivation phenomena, which are correlated to carbon deposition on the catalyst, were observed with all tested fuels, except for methane and biofuel.展开更多
Abstract： This paper presents a coupled multi-body and FEM （finite element method）-BEM （boundary element method） methodology used to carry out a comprehensive NVH （noise, vibration and harshness） investigation ...Abstract： This paper presents a coupled multi-body and FEM （finite element method）-BEM （boundary element method） methodology used to carry out a comprehensive NVH （noise, vibration and harshness） investigation of a four-cylinder internal combustion engine prototype. Firstly, a MBDS （multi-body dynamic simulation） of the internal combustion engine has been carried out, at a defined operating condition, in order to determine the excitation force of the powertrain exciting the cylinder block. In this way, the dynamics of the engine powertrain have been described taking into account both the effects of the gas forces of the combustion process and the inertia forces of the moving parts. Afterwards, the cylinder block excitation forces have been used to evaluate the engine block vibrations and to predict the external noise radiated with both the well-known ATV （acoustic transfer vectors） and MATV （modal acoustic transfer vectors） methodologies at a distance of 1 m from the engine, according to the standard ISO 3744. The dynamics of the engine powertrain and its vibro-acoustic behaviour have been described using LMS （learning management system） Engineering Innovation Virtual.Lab tools.展开更多
Road transport exhaust emissions represent the main sources of atmospheric pollution in urban areas, due to the growing number of circulating vehicles and travelled distances. In order to reduce this pollution source,...Road transport exhaust emissions represent the main sources of atmospheric pollution in urban areas, due to the growing number of circulating vehicles and travelled distances. In order to reduce this pollution source, stricter emission standards are periodically set by governments through- out the world. Consequently, the concentrations of gaseous pollutants and particulate mass to be measured during type-approval tests of new vehicles are becoming progressively lower;moreover from 2011, diesel cars have to comply with particle number limit. In order to assess emission levels of different technology vehicles and investigate the use of a particulate number measurement technique at the exhaust of very low-emitting vehicles, an experimental activity was carried out on three in-use vehicles: a diesel car equipped with a particulate trap (DPF), a hybrid gasoline-elec- tric car and a bi-fuel passenger car fuelled with compressed natural gas (CNG). Cold and hot gaseous and particulate emission factors and fuel consumption were measured during the execution of real and regulatory driving cycles on a chassis dynamometer. Particulate was characterized in terms of mass only for the diesel car and of particle number for all vehicles. The emissions measured over the NEDC show that all three vehicles comply with their standard limits, except CO for CNG passenger car and NOx for diesel car. Cold start influences CO and HC emissions and fuel consumption for all the tested vehicles and in particular for the hybrid car. The real driving cycle is the most critical pattern for the emissions of almost all pollutants. During constant speed tests, the emissions of particles of hybrid car are an order of magnitude lower than those of the CNG car.展开更多
This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the applicatio...This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the application of adsorption processes in removal of light hydrocarbons from exhaust streams of the petrochemical industry and of light-duty gasoline vehicles under cold start conditions (C4-C5 paraffins and olefins). The materials investigated were 5A and Ferrierite zeolites, characterized by different pore opening and Si/Al ratio. Equilibrium isotherm curves at room temperature were determined by a gravimetric method on dehydrated zeolites, while breakthrough curves in dynamic tests were used to evaluate the adsorption properties of hydrated zeolites at low hydrocarbon partial pressure (0-1 kPa) and in experimental conditions close to those of a HC trap at the engine exhaust. The experimental results regarding the adsorption capacities were discussed with the aim to understand how the physico-chemical characteristics of the adsorbent material could affect its trapping capability in adsorbing different types of hydrocarbons.展开更多
Energy valorization of organic waste material is nowadays an assessed practice of circular economy.Combined heat and power(CHP)technologies based on biomass gasification represent viable substitutes to traditional ene...Energy valorization of organic waste material is nowadays an assessed practice of circular economy.Combined heat and power(CHP)technologies based on biomass gasification represent viable substitutes to traditional energy conversion units based on combustion,whose need has recently experienced a huge growth,due to the increasing concerns about the release of greenhouse gases(GHGs)emissions and the related effects on climate changes.At present,only a few solutions have yet achieved a level of full development for commercialization.One of them is the system developed by CMD,the CMD ECO20,made of a gasifier,a syngas cleaning system and a spark ignition internal combustion engine working as a co-generator.In the present work,a numerical model is developed to study this system into detail and search for optimal controlling parameters.The simulation relies on a combined use of the Thermoflex?environment and a proper one-dimensional(1D)model of the engine module built within GT-Suite?.An original contribution is given to the turbulent combustion model that accounts for the laminar flame speed of the specific syngas.The numerical model,that covers the entire biomass-to-energy conversion process,is validated under real operative conditions.The final purpose of the work is the optimization of input parameters,as the initial biomass moisture content,the equivalence ratio at the gasifier or the timing of spark advance,to maximize the system electrical energy output.展开更多
Model reference adaptive control is a viable control method to impose the demanded dynamics on plants whose parameters are affected by large uncertainty. In this paper, we show by means of experiments that robust adap...Model reference adaptive control is a viable control method to impose the demanded dynamics on plants whose parameters are affected by large uncertainty. In this paper, we show by means of experiments that robust adaptive methods can effectively face nonlinearities that are common to many automotive electromechanical devices. We consider here, as a representative case study, the control of a strongly nonlinear automotive actuator. The experimental results confirm the effectiveness of the method to cope with unmodeled nonlinear terms and unknown parameters. In addition, the engineering performance indexes computed on experimental data clearly show that the robust adaptive strategy provides better performance compared with those given by a classical model-based control solution with fixed gains.展开更多
In the present article we characterized the emissions at the exhaust of a Common Rail （CR） diesel engine, representative of lightduty class, equipped with a catalyzed diesel particulate filter （CDPF） in controlled...In the present article we characterized the emissions at the exhaust of a Common Rail （CR） diesel engine, representative of lightduty class, equipped with a catalyzed diesel particulate filter （CDPF） in controlled environment. The downstream exhausts were directly analyzed （for PM, CO, CO/, Oz, HCs, NOx） by infrared and electrochemical sensors, and SEM-EDS microscope; heavy metals were chemically analyzed using mosses and lichens in bags, and glass-fibre filters all exposed at the engine exhausts. The highest particle emission value was in the 7-54 nm size range; the peak concentration rose until one order of magnitude for the highest load and speed. Particle composition was mainly carbonaceous, associated to noticeable amounts of Fe and silica fibres. Moreover, the content of Cu, Fe, Na, Ni and Zn in both moss and lichen, and of A1 and Cr in moss, was significantly increased. Glass-fibre filters were significantly enriched in A1, B, Ba, Cu, Fe, Na, and Zn. The role of diesel engines as source of carbonaceous nanoparticles has been confirmed, while further investigations in controlled environment are needed to test the catalytic muffler as a possible source of silica fibres considered very hazardous for human health.展开更多
文摘In this article, the aptitude of natural gas as feedstock in steam reforming process for hydrogen production is compared with that of different liquid fuels （pure compounds and commercial fuels）, with the aim to investigate the potentialities of biofuels to overcome the CO2 emission problems deriving from fossil fuel processing. The performances of a nickel based catalyst （commercially used in steam reforming of natural gas） were evaluated in terms of feed conversion and yield to the different products as function of temperature, space velocity and water/fuel ratio. Furthermore, a preliminary evaluation of catalyst durability was effected by monitoring yield to H2 versus time on stream and measuring coke formation at the end of experimental tests. High yields to hydrogen were obtained with all fuels investigated, whereas the deactivation phenomena, which are correlated to carbon deposition on the catalyst, were observed with all tested fuels, except for methane and biofuel.
文摘Abstract： This paper presents a coupled multi-body and FEM （finite element method）-BEM （boundary element method） methodology used to carry out a comprehensive NVH （noise, vibration and harshness） investigation of a four-cylinder internal combustion engine prototype. Firstly, a MBDS （multi-body dynamic simulation） of the internal combustion engine has been carried out, at a defined operating condition, in order to determine the excitation force of the powertrain exciting the cylinder block. In this way, the dynamics of the engine powertrain have been described taking into account both the effects of the gas forces of the combustion process and the inertia forces of the moving parts. Afterwards, the cylinder block excitation forces have been used to evaluate the engine block vibrations and to predict the external noise radiated with both the well-known ATV （acoustic transfer vectors） and MATV （modal acoustic transfer vectors） methodologies at a distance of 1 m from the engine, according to the standard ISO 3744. The dynamics of the engine powertrain and its vibro-acoustic behaviour have been described using LMS （learning management system） Engineering Innovation Virtual.Lab tools.
文摘Road transport exhaust emissions represent the main sources of atmospheric pollution in urban areas, due to the growing number of circulating vehicles and travelled distances. In order to reduce this pollution source, stricter emission standards are periodically set by governments through- out the world. Consequently, the concentrations of gaseous pollutants and particulate mass to be measured during type-approval tests of new vehicles are becoming progressively lower;moreover from 2011, diesel cars have to comply with particle number limit. In order to assess emission levels of different technology vehicles and investigate the use of a particulate number measurement technique at the exhaust of very low-emitting vehicles, an experimental activity was carried out on three in-use vehicles: a diesel car equipped with a particulate trap (DPF), a hybrid gasoline-elec- tric car and a bi-fuel passenger car fuelled with compressed natural gas (CNG). Cold and hot gaseous and particulate emission factors and fuel consumption were measured during the execution of real and regulatory driving cycles on a chassis dynamometer. Particulate was characterized in terms of mass only for the diesel car and of particle number for all vehicles. The emissions measured over the NEDC show that all three vehicles comply with their standard limits, except CO for CNG passenger car and NOx for diesel car. Cold start influences CO and HC emissions and fuel consumption for all the tested vehicles and in particular for the hybrid car. The real driving cycle is the most critical pattern for the emissions of almost all pollutants. During constant speed tests, the emissions of particles of hybrid car are an order of magnitude lower than those of the CNG car.
文摘This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the application of adsorption processes in removal of light hydrocarbons from exhaust streams of the petrochemical industry and of light-duty gasoline vehicles under cold start conditions (C4-C5 paraffins and olefins). The materials investigated were 5A and Ferrierite zeolites, characterized by different pore opening and Si/Al ratio. Equilibrium isotherm curves at room temperature were determined by a gravimetric method on dehydrated zeolites, while breakthrough curves in dynamic tests were used to evaluate the adsorption properties of hydrated zeolites at low hydrocarbon partial pressure (0-1 kPa) and in experimental conditions close to those of a HC trap at the engine exhaust. The experimental results regarding the adsorption capacities were discussed with the aim to understand how the physico-chemical characteristics of the adsorbent material could affect its trapping capability in adsorbing different types of hydrocarbons.
文摘Energy valorization of organic waste material is nowadays an assessed practice of circular economy.Combined heat and power(CHP)technologies based on biomass gasification represent viable substitutes to traditional energy conversion units based on combustion,whose need has recently experienced a huge growth,due to the increasing concerns about the release of greenhouse gases(GHGs)emissions and the related effects on climate changes.At present,only a few solutions have yet achieved a level of full development for commercialization.One of them is the system developed by CMD,the CMD ECO20,made of a gasifier,a syngas cleaning system and a spark ignition internal combustion engine working as a co-generator.In the present work,a numerical model is developed to study this system into detail and search for optimal controlling parameters.The simulation relies on a combined use of the Thermoflex?environment and a proper one-dimensional(1D)model of the engine module built within GT-Suite?.An original contribution is given to the turbulent combustion model that accounts for the laminar flame speed of the specific syngas.The numerical model,that covers the entire biomass-to-energy conversion process,is validated under real operative conditions.The final purpose of the work is the optimization of input parameters,as the initial biomass moisture content,the equivalence ratio at the gasifier or the timing of spark advance,to maximize the system electrical energy output.
文摘Model reference adaptive control is a viable control method to impose the demanded dynamics on plants whose parameters are affected by large uncertainty. In this paper, we show by means of experiments that robust adaptive methods can effectively face nonlinearities that are common to many automotive electromechanical devices. We consider here, as a representative case study, the control of a strongly nonlinear automotive actuator. The experimental results confirm the effectiveness of the method to cope with unmodeled nonlinear terms and unknown parameters. In addition, the engineering performance indexes computed on experimental data clearly show that the robust adaptive strategy provides better performance compared with those given by a classical model-based control solution with fixed gains.
文摘In the present article we characterized the emissions at the exhaust of a Common Rail （CR） diesel engine, representative of lightduty class, equipped with a catalyzed diesel particulate filter （CDPF） in controlled environment. The downstream exhausts were directly analyzed （for PM, CO, CO/, Oz, HCs, NOx） by infrared and electrochemical sensors, and SEM-EDS microscope; heavy metals were chemically analyzed using mosses and lichens in bags, and glass-fibre filters all exposed at the engine exhausts. The highest particle emission value was in the 7-54 nm size range; the peak concentration rose until one order of magnitude for the highest load and speed. Particle composition was mainly carbonaceous, associated to noticeable amounts of Fe and silica fibres. Moreover, the content of Cu, Fe, Na, Ni and Zn in both moss and lichen, and of A1 and Cr in moss, was significantly increased. Glass-fibre filters were significantly enriched in A1, B, Ba, Cu, Fe, Na, and Zn. The role of diesel engines as source of carbonaceous nanoparticles has been confirmed, while further investigations in controlled environment are needed to test the catalytic muffler as a possible source of silica fibres considered very hazardous for human health.
