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The presented article will describe an 'effect-cause' model for the purpose of simulating the energy consumption of DC fed light rail vehicles. The model will assess the advantages of hybrid vehicles in terms of energy consumption, network power and voltage variations, line current and losses; and will help sizing and designing a supercapacitor based energy storage system (ESS) for both on-board, and stationary applications. The proposed modeling needs to allow the ESS sizing according to the objective that needs to be achieved, being braking energy recovery, voltage drop compensation and peak power shaving the most common goals of ESS use in hybrid vehicles. The needed power and energy levels will vary in function of the vehicle features and the driving cycle followed. This all can be determined by the quasi-static simulation tool to ease the design process. Another objective of the modeling tool is to evaluate the behaviour of the vehicle power flow controller, which manages the power from/to the ESS in function of the state of several variables.

Capítulos en libros This paper assesses the scalability and replicability of smart grid projects, by means of the identification of limitations and barriers faced by these projects. Factors have been identified that impact a project s scalability and replicability by means of a review of demonstration projects. The factors are of technical, economic, regulatory and social acceptance nature, and they describe requirements for scalability and replicability. Data was collected from ongoing European smart grid demonstration projects through the use of an elaborated questionnaire on the identified factors. Which allowed to quantify the status quo to what extent projects have taken these factors into account. Dew to their nature the derived factors can be categorized in technical, economic and regulatory & stakeholder related factor areas The obtained results allowed the identification of barriers, i.e. limitations regarding the scalability and replicability of smart grid projects. In particular projects face barriers regarding the absence of standards, the physical limits of the existing infrastructure, the absence of cost-benefit analyses, the neglect of varying macro-economic factors, stakeholder involvement and from the dependency of projects on regional or national regulatory frameworks and market designs. info:eu-repo/semantics/publishedVersion

Urban environments provide opportunities for greater resource efficiency and the fostering of urban ecosystems. Brownfield areas are a typical example of underused land resources. Brownfield redevelopment projects that include green infrastructure allow for further ecosystems to be accommodated in urban environments. Green infrastructure also deliver important urban ecosystem services (UES) to local residents, which can greatly contribute to improving quality of life in cities. In this case study, we quantify and assess the economic value of five UES for a brownfield redevelopment project in Antwerp, Belgium. The assessment is carried out using the “Nature Value Explorer” modelling tool. The case includes three types of green infrastructure (green corridor,infiltration gullies and green roofs) primarily intended to connect nature reserves on the urban periphery and to avoid surface runoff. The green infrastructure also provides air filtration, climate regulation, carbon sequestration and recreation ecosystem services. The value of recreation far exceeds other values, including the value of avoided runoff. The case study raises crucial questions as to whether existing UES valuation approaches adequately account for the range of UES provided and whether such approaches can be improved to achieve more accurate and reliable value estimates in future analyses.

Abstract Silicon carbide-based filter elements were catalytically activated to provide filter elements for catalytic tar removal from biomass-derived syngas. The filter element support was coated with CeO 2 , CaO–Al 2 O 3 and MgO with a specific surface of 7.4, 15.9 and 21.9 m 2 /g synthesized by exo-templating with activated carbon. Doping of a MgO coated filter element with 60 wt% NiO has led to an increase of the specific surface from 0.15 to 0.21 m 2 /g, whereas in case of a MgO–Al 2 O 3 coated filter element a decrease from 1.18 to 0.91 m 2 /g was found. An increase of the NiO loading from 6 to 60 wt% on a MgO coated filter element resulted in an increase of the naphthalene conversion from 91 to 100% at 800 °C and a face velocity of 2.5 cm/s at a naphthalene concentration of 5 g/Nm 3 in model biomass gasification gas. In case of a MgO–Al 2 O 3 coated filter element with 60 wt% NiO in addition to complete naphthalene conversion in the absence of H 2 S, a higher conversion of 66% was found in the presence of 100 ppmv H 2 S compared to 49% of the MgO–NiO coated filter element. After scaling up of the catalytic activation procedure to a 1520 mm long filter candle, which shows an acceptable differential pressure of 54.9 mbar, 58 and 97% naphthalene conversion was achieved in the presence and absence of H 2 S, respectively. The calculated WHSV value of 209.6 Nm 3 h −1 kg −1 indicates the technical feasibility of a further increase of the catalytic performance by an increase of the NiO loading.

Abstract The present paper proposes a way to introduce chemical reactions in composite curves, in such a way that the irreversibility’s generated by the chemical reaction are expressed as equivalent thermal diffusion. The heat of reaction is considered to be released at a “reversible reaction temperature” and the diffusion between this reversible temperature and the actual temperature generates the actual exergy destruction. Corresponding hot and cold curve contributions result in the composite curves, which visualizes the exergy destruction and the chemical pinches which are present in the exchanger and reactor network. The concept is illustrated through an application on chemical recuperation in a gas turbine cycle.

Abstract Resulting from a Ph.D. research a Vehicle Simulation Programme (VSP) is proposed and continuously developed. It allows simulating the behaviour of electric, hybrid, fuel cell and internal combustion vehicles while driving any reference cycle [Simulation software for comparison and design of electric, hybrid electric and internal combustion vehicles with respect to energy, emissions and performances, Ph.D. Thesis, Department Electrical Engineering, Vrije Universiteit Brussel, Belgium, April 2000]. The goal of the simulation programme is to study power flows in vehicle drive trains and the corresponding component losses, as well as to compare different drive train topologies. This comparison can be realised for energy consumption and emissions as well as for performances (acceleration, range, maximum slope, etc.). The software package and its validation are described in [J. Automot. Eng., SAE IEE 215 (9) (2001) 1043L]. Different hybrid and electric drive trains are implemented in the software [Views on hybrid drive train power management strategies, in: Proceedings of the EVS-17, Montreal, Canada, October 2000]. The models used for the energy sources like fuel cells, batteries, ultracapacitors, flywheels and engine-generator units will be discussed in this paper in three stages: first their functionality and characteristics are described, next the way these characteristics can be implemented in a simulation model will be explained and finally some calculation results will illustrate the approach. This paper is aimed to give an overview of simulation models of energy sources for battery, hybrid and fuel cell electric vehicles. Innovative is the extreme modularity and exchangeability of different components functioning as energy sources. The unique iteration algorithm of the simulation programme allows to accurately simulate drive train maximum performances as well as all kind of power management strategies in different types of hybrid drive trains [IEEE Trans. Veh. Technol., submitted for publication].

Abstract Highly three-dimensional and complex flow structure within the tip gap of an axial flow turbine is a substantial source of aerodynamic loss and heat transfer due to the interaction between the tip leakage vortex, secondary flows and the main passage flow. Most contemporary shroudless high pressure (HP) turbine designs employ squealer tips for durability, structural, aerodynamic design and heat transfer reasons. The present research deals with the influence of squealer width and height on the aerothermal performance of a HP turbine blade. In this study, four different squealer heights and seven squealer width values are investigated using a computational approach for an axial turbine blade depicting an E 3 “Energy Efficient Engine” design. The specific HP turbine airfoil under investigation is identical to the rotor tip profile of the Axial Flow Turbine Research Facility (AFTRF) of the Pennsylvania State University. Numerical calculations are performed by solving the three-dimensional, steady and turbulent form of the Reynolds-Averaged Navier-Stokes (RANS) equations. A two-equation turbulence model, Shear Stress Transport (SST) k-ω is used in the present set of calculations. The current numerical predictions show a very good agreement with the extensive aerodynamic measurements obtained in the nozzle guide vane passages of AFTRF. The results indicate that determining proper squealer width and height is crucial to obtain better aerothermal performance in the form of reduced aerodynamic loss and heat transfer to the tip platform. Extensive numerical analysis within the tip gap reveals that increasing squealer height and reducing squealer width increases cavity volume leading to enlarged vortical structures near the pressure side and suction side of the cavity. Because of this enhanced vortical activity in the tip cavity, a blockage to the incoming pass-over flow is introduced and as a result tip leakage mass flow rate is reduced. While the tip leakage flow rate tends to decrease with increased height and reduced width, there is a strong effect from the squealer width and height combination due to the presence of complex interactions in the tip gap region. From a heat transfer point of view, decreasing squealer width and increasing squealer height noticeably reduces the overall Nu ‾ on the blade tip platform. Nu ‾ on the cavity floor, blade tip and squealer side walls are reduced depending on the increasing height and decreasing width values.

Sustainable agriculture leads today to important questions about the diversification of agricultural production and sources of income for farmers, the use of rural and arable land for food and non-food crops, the contribution of agriculture to climate change fighting and the supply of renewable energy. Bioenergy from agriculture is at the heart of these concerns, integrating sustainable development key components: environment and climate change, energy economics and energy supply, agriculture, rural and social development. The lack of primary and reliable data on bioenergy externalities from agriculture and the lack of decision-making tools are important non-technological barriers to the development of bioenergy from agriculture on a large scale, and, consequently, to the achievement of the national and regional objectives of sustainable development with respect to greenhouse gas mitigation, secure and diversified energy supply, rural development and employment and the future of agriculture. Furthermore, the recent worldwide controversies about transport biofuels, food shortages and increasing prices have demonstrated the urgent need for sustainability criteria applied to biofuels and bioenergy. Within this current sustainable development framework, a project entitled TEXBIAG integrating experts from 4 research institutions is financed by the Belgian Science Policy. The final objective of this project is to lead to an actual and significant contribution of bioenergy from agriculture to the mitigation of greenhouse gas emissions, to a secure and diversified energy supply and to farmers' incomes and rural development. To reach this final objective, the project develops three specific tools: (1) a database of primary quantitative data related to environmental and socio-economic impacts of bioenergy from agriculture integrating biomass logistics; (2) a mathematical model monetizing bioenergy externalities from agriculture; and (3) a prediction tool assessing the impacts of political decisions made in the framework ofthe development of bioenergy from agriculture on different economic sectors (energy, agriculture, industry, and environment). An integrated interface tool will be programmed where access to and update of the three tools will be prepared. The project methodology will be conducted for a given number of scenarios with sensitivity analysis wherever possible. The three main target groups that will benefit from the project are: the government officials and policy makers in the field of agriculture, energy and environment in Belgium and its two main regions, the small, medium and large energy companies and the agricultural sector