Search results for "fuel"
showing 10 items of 986 documents
EABOT – Energetic analysis as a basis for robust optimization of trigeneration systems by linear programming
2008
Abstract The optimization of synthesis, design and operation in trigeneration systems for building applications is a quite complex task, due to the high number of decision variables, the presence of irregular heat, cooling and electric load profiles and the variable electricity price. Consequently, computer-aided techniques are usually adopted to achieve the optimal solution, based either on iterative techniques, linear or non-linear programming or evolutionary search. Large efforts have been made in improving algorithm efficiency, which have resulted in an increasingly rapid convergence to the optimal solution and in reduced calculation time; robust algorithm have also been formulated, ass…
Grid integration of PEM fuel cell with multiphase switching for maximum power operation
2016
Energy storage in the form of electrolytic Hydrogen can play an important role for integration of intermittent renewable energy sources in the smart grid environment. Electrolytic Hydrogen can be used as a fuel in proton exchange membrane (PEM) fuel cell. In this work, a technique for multiphase switching of a DC-DC converter associated with grid integration of a PEM fuel cell stack for maximum power operation in non-dispatchable mode is proposed. The presented system consists of a PEM fuel cell stack which is operating in non-dispatchable mode of operation, DC-DC multiphase switching boost converter for maximum power operation and a grid tied three phase voltage source inverter (VSI). VSI …
An NTC zone compliant knock onset prediction model for spark ignition engines
2015
Abstract Pollutant emissions reduction and energy saving policies increased the production of Spark Ignition (SI) engines operated with gaseous fuels. Natural Gas (NG) and Liquefied Petroleum Gas (LPG), thanks to their low cost and low environmental impact represent the best alternative. Bi-fuel engines, which may run either with gasoline or with gas (NG or LPG), widely spread in many countries thanks to their versatility, high efficiency and low pollutant emissions: gas fueled vehicles, as example, are allowed to run in many limited traffic zones. In the last years, supercharged SI engines fueled with either gasoline or gaseous fuel, spread in the market. Thermodynamic simulations, widely …
Design and control of a novel multi-source renewable energy system
2014
In this paper, a novel multi-input, single-inductor architecture is proposed. An innovative hysteretic control strategy of both the output voltage and the sources operating point control is designed and tested. Benefits brought by the proposed architecture over existing solutions are widely investigated. As an example, the design of a 48 V dual input system which is fed by photovoltaic and thermo-electric generators is proposed. Design guidelines are given and simulation results are presented to test the efficiency of the proposed architecture.
Experimental characterization of PEM fuel cells by micro-models for the prediction of on-site performance
2009
This paper presents the results of an experimental analysis performed on a miniaturized, 6 We Proton Exchange Membrane Fuel Cell (PEMFC) system, integrated with on-site hydrogen production by electrolysis; in particular, the effects of environmental parameters such as the external temperature and the humidity on the performance of fuel cells are investigated. PEMFC systems are zero-emissions power technologies when they are fed with pure hydrogen (at concentration higher than 97%); also, being the only results of system operation the produced electricity and some pure water, when produced by renewable sources hydrogen can be considered an attractive alternative to fossil fuels and may concu…
Computational fluid dynamics and its application to transport processes
2007
Fluid transport behaviour is of great importance within the chemical process industry and in biotechnology. The complexity of this behaviour, reflected in the nature of the fundamental partial differential equations which describe it analytically, means that it has to be treated by numerical methods. In this paper the basic equations are given, and the approaches necessary to treat laminar and turbulent flows are carefully explained. As digital computers have increased in size, so has the comprehensiveness of the problems which can be treated, and the development of typical computer programs is described. Problems of accuracy and experimental validation are also surveyed, and it is shown th…
Improving the sustainability of transportation: environmental and functional benefits of right-turn by pass lanes at roundabouts
2015
The functional performances of conventional roundabouts (single-lane and multi-lane) and innovative roundabouts (spiral, flower, C and turbo) can be improved through right-turn bypass lanes controlled by stop, yield or free-flow signs. The article presents evaluations of the emissions of air pollutants (carbon dioxide, nitrogen oxides, particle pollution (PM10 and PM2.5)), fuel consumption and construction, management, energetic and environmental costs in roundabouts without or with bypass lanes (controlled by stop, yield or free-flow). The suggested methodology has a general character and can be applied as a multi-parametric criterion for choosing road intersections, although, in the prese…
Advancements in DEMO WCLL breeding blanket design and integration
2017
Summary The water-cooled lithium–lead breeding blanket is a candidate option for the European Demonstration Power Plant (DEMO) nuclear fusion reactor. This breeding blanket concept relies on the liquid lithium–lead as breeder–multiplier, pressurized water as coolant, and EUROFER as structural material. The current design is based on DEMO 2015 specifications and represents the follow-up of the design developed in 2015. The single-module-segment approach is employed. This is constituted by a basic geometry repeated along the poloidal direction. The power is removed by means of radial–toroidal (i.e., horizontal) water cooling tubes in the breeding zone. The lithium–lead flows in a radial–poloi…
Clean and Sustainable Biodiesel Production
2015
To date, the majority of world's primary energy is derived from fossil fuels. However, the fossil fuel recourses are in an inevitable decline as energy demand continues to grow exponentially with population growth, urbanization, and improved standards of living. Crude oil prices have recently risen several times and their current annual volatility exceeds 30%. The potential scarcity of fossil fuels has prompted a global search for alternative energy resources. Biodiesel fulfills the major requirements for production of alternative fuels such as feedstock availability, technical feasibility, and economic competitiveness. Together with other renewable biofuels, the use of biodiesel as a subst…
Renewable energy sources to fulfill the global energy needs of a country: The case study of Malta in Mediterranean Sea
2016
The paper shows the advantages using different energy resources for the islands of Malta. Moreover, this work is focused on the analysis of the wave energy potential along Malta's coasts. This important resource can be exploited to produce electrical energy using an innovative Point Absorber based on a new generator prototype realized by University of Palermo. The use of renewable source will reduce greenhouses emissions and increase the energy independence of Malta. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability [1]-[7].