Search results for "020209 energy"
showing 10 items of 1300 documents
Model Predictive Control for Shunt Active Filters With Fixed Switching Frequency
2016
This paper presents a modification to the classical Model Predictive Control algorithm, named Modulated Model Predictive Control, and its application to active power filters. The proposed control is able to retain all the advantages of a Finite Control Set Model Predictive Control whilst improving the generated waveforms harmonic spectrum. In fact a modulation algorithm, based on the cost function ratio for different output vectors, is inherently included in the MPC. The cost function-based modulator is introduced and its effectiveness on reducing the current ripple is demonstrated. The presented solution provides an effective and straightforward single loop controller, maintaining an excel…
Novel solutions for closed-loop Reverse Electrodialysis: thermodynamic characterisation and perspective analysis
2019
Abstract Closed-loop Reverse Electrodialysis is a novel technology to directly convert low-grade heat into electricity. It consists of a reverse electrodialysis (RED) unit where electricity is produced exploiting the salinity gradient between two salt-water solutions, coupled with a regeneration unit where waste-heat is used to treat the solutions exiting from the RED unit and restore their initial composition. One of the most important advantages of closed-loop systems compared to the open systems is the possibility to select ad-hoc salt solutions to achieve high efficiencies. Therefore, the properties of the salt solutions are essential to assess the performance of the energy generation a…
Improved Performance of a PV Solar Panel with Adaptive Neuro Fuzzy Inference System ANFIS based MPPT
2018
This article presents the development of an intelligent technique of Adaptive-Neuro-Fuzzy Inference System (ANFIS) based on Maximum Power Point Tracking (ANFIS-MPPT) algorithm with PI controller in order to increase the performances of the photovoltaic panel system below change atmospheric circumstances. In this work, the mathematical principles of the ANFIS method were presented and developed using the software Matlab/Simulink. Moreover, the effectiveness of this ANFIS-MPPT technique is demonstrated by a comparison of the obtained results with others obtained from a classical (Perturb & Observe) P & O-MPPT method.From the analysis of the obtained results, the ANFIS-MPPT command provide bet…
A Novel Deep Learning Stack for APT Detection
2019
We present a novel Deep Learning (DL) stack for detecting Advanced Persistent threat (APT) attacks. This model is based on a theoretical approach where an APT is observed as a multi-vector multi-stage attack with a continuous strategic campaign. To capture these attacks, the entire network flow and particularly raw data must be used as an input for the detection process. By combining different types of tailored DL-methods, it is possible to capture certain types of anomalies and behaviour. Our method essentially breaks down a bigger problem into smaller tasks, tries to solve these sequentially and finally returns a conclusive result. This concept paper outlines, for example, the problems an…
Effect of biomass features on oxygen transfer in conventional activated sludge and membrane bioreactor systems
2019
Abstract The aim of the present study was to compare the oxygen transfer efficiency in a conventional activated sludge and a membrane bioreactor system. The oxygen transfer was evaluated by means of the oxygen transfer coefficient and α-factor calculation, under different total suspended solids concentration, extracellular polymeric substances, sludge apparent viscosity and size of the flocs. The oxygen transfer coefficient and α-factor showed an exponential decreasing trend with total suspended solid, with a stronger oxygen transfer coefficient dependence in the conventional activated sludge compared to the membrane bioreactor. It was noted that the oxygen transfer coefficient in the conve…
Green geopolymeric concrete using grits for applications in construction
2018
Abstract This work investigates the production a green geopolymer-based concrete for a sustainable construction material using biomass wastes from a kraft pulp industry: fly ash (as main alumina-silicate source) and grits (as aggregate). Moreover, a simple, reproducible, ambient temperature, and low-cost manufacture is followed. Mix design aims to maximize wastes incorporation and optimize the mechanical performance. Preliminary tests indicate that the used wastes may be successfully employed to produce green geopolymeric concretes with satisfying mechanical performance (up to 18 MPa), according to the European standards. Furthermore, they represent a viable solution to reduce the environme…
Aspen Plus process-simulation model: Producing biogas from VOC emissions in an anaerobic bioscrubber
2018
A process-simulation model for a novel process consisted of an anaerobic bioscrubber was developed in Aspen Plus®. A novel approach was performed to implement the anaerobic reactor in the simulation, enabling it to be connected to the scrubber. The model was calibrated and validated using data from an industrial prototype that converted air emissions polluted with volatile organic compounds with an average daily concentration of 1129 mgC Nm−3 into bioenergy for more than one year. The scrubber, which showed a removal efficiency within 83-93%, was successfully predicted with an average absolute relative error of 5.2 ± 0.08% using an average height-to-theoretical-plate value of 1.05 ± 0.08 m …
Selective recovery of phosphorus as AlPO4 from silicon-free CFB-derived fly ash leachate
2018
The prospect of phosphorus (P) recovery from siliceous fly ash was investigated. The phosphorus content in the pristine fly ash was 1.21%. Obtaining pure phosphorus products from fly ash is very challenging because of high concentration of other elements, silicon (Si) at 17.3% being the major contaminant. The fly ash was fractionated with sieve size of 125 μm to concentrate the phosphorus in the small-size fraction, which also facilitated the removal of 78% of silica (Si) in the solid phase. The fractionated fly ash was treated with 8 M HCl in order to remove 98% of Si by aging (5 h) of leachate until precipitation of Si-gel, and a phosphorus-rich solution is obtained. Iron (Fe) is also con…
Adopting magnetocaloric heat pumping and refrigeration for electrical vehicle
2017
International audience; Refrigeration process is based on conventional gas compression and expansion techniques. However, this technique has numerous disadvantages since it generates greenhouse gas and is partly responsible for global warming. This paper exposes analternative method: magnetocaloric refrigeration that presents the advantage to combine high-energy efficiency and respect of theenvironment. Magnetic heat pumping and cooling is compared to conventional method applied on vehicle air conditioning system.Simulation results are used to demonstrate the approach.
Electromechanical Numerical Analysis of an Air-Core Pulsed Alternator via Equivalent Network Formulation
2017
In this paper, the numerical analysis on an air-core pulsed alternator is presented. Since compulsators are characterized by very fast electromechanical transients, their accurate analysis requires strong coupling between the equations governing the electrical and the mechanical behaviors. The device is investigated by using a dedicated numerical code capable to take into account eddy currents, compensating windings, as well as the excitation/control circuits. Furthermore, the code is capable of modeling centrifugal forces and vibrations acting on the shaft due to electric and mechanical unbalances or to misalignments of the shaft from its centered position. This makes the code a very power…