Search results for "energy [jet]"
showing 10 items of 1760 documents
A regenerative braking system for internal combustion engine vehicles using supercapacitors as energy storage elements - Part 2: Simulation results
2020
Abstract In this two-part work, an electric kinetic energy recovery system (e-KERS) for internal combustion engine vehicle (ICEV) is presented and its performance evaluated through numerical simulations. The KERS proposed is based on the use of a supercapacitor as energy storage, interfaced to a brushless machine through a properly designed power converter. In Part 1, the system is described and analysed, and the mathematical model used for the simulations is presented. For each component of the KERS, the real efficiency and the power or energy limitations are adequately considered. In Part 2, the energetic and economic advantages attainable by the proposed KERS are evaluated using MATLAB S…
A regenerative braking system for internal combustion engine vehicles using supercapacitors as energy storage elements - Part 1: System analysis and …
2020
Abstract In this two-part work, an electric kinetic energy recovery system (e-KERS) for internal combustion engine vehicle (ICEV) is presented, and its performance evaluated through numerical simulations. The KERS proposed is based on the use of a supercapacitor as energy storage, interfaced to a brushless machine through a properly designed power converter. In part 1, the system is described and analysed, and the mathematical model used for the simulations is presented. For each component of the KERS, the real efficiency, and the power or energy limitations are adequately considered. In part 2, the energetic and economic advantages attainable by the proposed KERS are evaluated using MATLAB…
An Algorithm for Optimal Sizing of BESS in Smart Islands Energy Communities: the Case of Pantelleria
2021
Energy Communities (EC) are a promising solution to reduce both the carbon footprint and the impact of Renewable Energy Sources (RES) on the distribution grid. Based on a simple energy sharing principle, EC can be decisive in the next future energy transition of some problematic territories, like small islands not supplied by the main power grid. By integrating Battery Energy Storage Systems (BESS), it is possible to improve the EC performance. However, due to the still high BESSs unit prices, the goal of this work is to find the optimal size of BESSs, under various conditions, which combines the need to maximize shared energy and the possible revenue of EC actors. To set this multi-objecti…
Study of thermomagnetic energy conversion driven by renewable energy
2017
Magnetic heating, refrigeration and energy conversion have been defined very important challenges for promising environmentally future choices. Recent studies are focused attention on new thermomagnetic systems, devices working through thermomagnetic effect, driven by renewable energies. The aim of this work is a case study presentation of new thermomagnetic energy prototype coupled with renewable technologies or industrial waste heat. The paper is divided into four sections: the first gives a general state of art about magneto-caloric energy conversion systems, the second describes all general thermodynamics and magnetic laws governing the process, the third and fourth sections study in mo…
A COMPARISON BETWEEN COMBUSTION PHASE INDICATORS FOR OPTIMAL SPARK TIMING
2008
The closed-loop control of internal combustion engine spark timing may be accomplished by means of a combustion phase indicator, i.e., a parameter, derived from in-cylinder pressure analysis, whose variation is mainly referable to combustion phase shift and assumes a fixed reference value under optimal spark timing operation. The aim of the present work is a comparison between different combustion phase indicators, focusing on the performance attainable by a feedback spark timing control, which uses the indicator as pilot variable. An extensive experimental investigation has been carried out, verifying the relationship between indicators’ optimal values and the main engine running parameter…
Adsorption of hydrogen isotopes in the zeolite NaX: Experiments and simulations
2017
Abstract Among the different methods to separate hydrogen isotopes one is based on the physisorption at low temperature (below 100 K) where quantum effects induce a particular behavior. In the present work, we study the adsorption of single H 2 and D 2 on the zeolite NaX by combining experiments (manometry) from 30 to 150 K and molecular dynamics simulations at 40 and 77 K. Simulations also include the adsorption analysis for T 2 . Adsorption on NaX membranes is simulated and quantum corrections are introduced by using the well-known Feynman–Hibbs approach into the interaction potentials. Experimental adsorption isotherms are reproduced by using the Toth equation and it is shown that the ad…
Unveiling Molecular Changes in Water by Small Luminescent Nanoparticles
2017
This work was supported by the Spanish Ministerio de Educación y Ciencia (MAT2013-47395-C4-1-R and MAT2016-75362-C3-1- R) and by the COST Action CM1403. L.L.-P. thanks the Universidad Autónoma de Madrid for the “Formación de Personal Investigador (FPI-UAM)” program. P.H.-G. thanks the Spanish Ministerio de Economia y Competitividad (MINECO) for the Juan de la Cierva program. The authors from the University of Belgrade acknowledge the financial support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (Project Nos. 45020 and 172056). M.I.M. thanks financial support from the Spanish Ministerio de Economía y Competitividad (MICINN) Project FIS2015-69…
Excitonic States in Semiconducting Two-dimensional Perovskites
2018
Hybrid organic/inorganic perovskites have emerged as efficient semiconductor materials for applications in photovoltaic solar cells with conversion efficiency above 20 \%. Recent experiments have synthesized ultra-thin two-dimensional (2D) organic perovskites with optical properties similar to those of 2D materials like monolayer MoS$_2$: large exciton binding energy and excitonic effects at room temperature. In addition, 2D perovskites are synthesized with a simple fabrication process with potential low-cost and large-scale manufacture. Up to now, state-of-the-art simulations of the excitonic states have been limited to the study of bulk organic perovskites. A large number of atoms in the …
A reaction engineering approach to kinetic analysis of photocatalytic reactions in slurry systems
2016
Abstract The knowledge of the rate equation is fundamental for the assessment of the activity of the photocatalytic material and for the study, design and optimization of photocatalytic reactors. In the case of photocatalytic reactions, the local volumetric rate of photon absorption (LVRPA) affects the reaction rate and its inherently uneven distribution within a “slurry” reactor makes complex a correct kinetic analysis. In the present work it is shown which are the critical aspects of the kinetic analysis in slurry reactors and how to carry out photocatalytic experiments to minimize the misinterpretations of the experimental results. In particular, the influence of the type of illumination…
Energy harvesting by waste acid/base neutralization via bipolar membrane reverse electrodialysis
2020
Bipolar Membrane Reverse Electrodialysis (BMRED) can be used to produce electricity exploiting acid-base neutralization, thus representing a valuable route in reusing waste streams. The present work investigates the performance of a lab-scale BMRED module under several operating conditions. By feeding the stack with 1 M HCl and NaOH streams, a maximum power density of ~17 W m−2 was obtained at 100 A m−2 with a 10-triplet stack with a flow velocity of 1 cm s−1, while an energy density of ~10 kWh m−3 acid could be extracted by a complete neutralization. Parasitic currents along feed and drain manifolds significantly affected the performance of the stack when equipped with a higher number of t…