Search results for " Optimization"
showing 10 items of 2367 documents
Hydraulic Characterization of the Full Scale Mock-Up of the DEMO Divertor Outer Vertical Target
2021
In the frame of the pre-conceptual design activities of the DEMO work package DIV-1 “Divertor Cassette Design and Integration” of the EUROfusion program, a mock-up of the divertor outer vertical target (OVT) was built, mainly in order to: (i) demonstrate the technical feasibility of manufacturing procedures; (ii) verify the hydraulic design and its capability to ensure a uniform and proper cooling for the plasma facing units (PFUs) with an acceptable pressure drop; and (iii) experimentally validate the computational fluid-dynamic (CFD) model developed by the University of Palermo. In this context, a research campaign was jointly carried out by the University of Palermo and ENEA to experimen…
Review of the Hydrogen Evolution Reaction—A Basic Approach
2021
An increasing emphasis on energy storage has resulted in a surge of R&D efforts into producing catalyst materials for the hydrogen evolution reaction (HER) with emphasis on decreasing the usage of platinum group metals (PGMs). Alkaline water electrolysis holds promise for satisfying future energy storage demands, however the intrinsic potential of this technology is impeded by sluggish reaction kinetics. Here, we summarize the latest efforts within alkaline HER electrocatalyst design, where these efforts are divided between three catalyst design strategies inspired by the three prevailing theories describing the pH-dependence of the HER activity. Modifying the electronic structure of a …
Switching Frequency Effects on the Efficiency and Harmonic Distortion in a Three-Phase Five-Level CHBMI Prototype with Multicarrier PWM Schemes: Expe…
2022
The current climatic scenario requires the use of innovative solutions to increase the production of electricity from renewable energy sources. Multilevel Power Inverters are a promising solution to improve the penetration of renewable energy sources into the electrical grid. Moreover, the performance of MPIs is a function of the modulation strategy employed and of its features (modulation index and switching frequency). This paper presents an extended and experimental analysis of three-phase five-level Cascaded H-Bridges Multilevel Inverter performance in terms of efficiency and harmonic content considering several MC PWM modulation strategies. In detail, the CHBMI performance is analyzed …
Sedimentation Tanks for Treating Rainwater: CFD Simulations and PIV Experiments
2021
The removal of solids is the most important step when treating rainwater. The article evaluates two designs of sedimentation tanks that can be used for the continuous separation of fine particles from water: OS—standard sedimentation tanks, and OW—swirl sedimentation tanks. The tanks were studied by conducting computational fluid dynamics (CFD) modeling and particle image velocimetry (PIV) experiments. The settling process in sedimentation tank was carried out at varying operating flow rates. A tank with a modified structure was used for the tests, where water was supplied by a nozzle placed at an angle. This solution made it possible to obtain a rotational flow that transported the suspend…
Sea Wave Energy. A Review of the Current Technologies and Perspectives
2021
The proposal of new technologies capable of producing electrical energy from renewable sources has driven research into seas and oceans. Research finds this field very promising in the future of renewable energies, especially in areas where there are specific climatic and morphological characteristics to exploit large amounts of energy from the sea. In general, this kind of energy is referred to as six energy resources: waves, tidal range, tidal current, ocean current, ocean thermal energy conversion, and saline gradient. This review has the aim to list several wave-energy converter power plants and to analyze their years of operation. In this way, a focus is created to understand how many …
A Model of DC-DC Converter with Switched-Capacitor Structure for Electric Vehicle Applications
2022
In this paper, a DC-DC converter with an innovative topology for automotive applications is proposed. The goal of the presented power converter is the electrical storage system management of an electric vehicle (EV). The presented converter is specifically compliant with a 400 V battery, which represents the high-voltage primary source of the system. This topology is also able to act as a bidirectional power converter, so that in this case, the output section is an active stage, which is able to provide power as, for example, in the case of a low-voltage battery or a supercapacitor. The proposed topology can behave either in step-down or in step-up mode, presenting in both cases a high gain…
Voltage-Based Droop Control of Electric Vehicles in Distribution Grids under Different Charging Power Levels
2021
If left uncontrolled, electric vehicle charging poses severe challenges to distribution grid operation. Resulting issues are expected to be mitigated by charging control. In particular, voltage-based charging control, by relying only on the local measurements of voltage at the point of connection, provides an autonomous communication-free solution. The controller, attached to the charging equipment, compares the measured voltage to a reference voltage and adapts the charging power using a droop control characteristic. We present a systematic study of the voltage-based droop control method for electric vehicles to establish the usability of the method for all the currently available resident…
Efficiency advantages of the separated electric compound propulsion system for CNG hybrid vehicles
2021
As is widely known, internal combustion engines are not able to complete the expansion process of the gas inside the cylinder, causing theoretical energy losses in the order of 20%. Several systems and methods have been proposed and implemented to recover the unexpanded gas energy, such as turbocharging, which partially exploits this energy to compress the fresh intake charge, or turbo-mechanical and turbo-electrical compounding, where the amount of unexpanded gas energy not used by the compressor is dedicated to propulsion or is transformed into electric energy. In all of these cases, however, maximum efficiency improvements between 4% and 9% have been achieved. In this work, the authors d…
Novel Concept for Electro-Hydrostatic Actuators for Motion Control of Hydraulic Manipulators
2021
Self-contained hydraulic cylinders have gained popularity in the recent years but have not been implemented for high power articulated hydraulic manipulators. This paper presents a novel concept for an electro-hydrostatic actuator applicable to large hydraulic manipulators. The actuator is designed and analyzed to comply with requirements such as load holding, overload handling, and differential flow compensation. The system is analyzed during four quadrant operation to investigate energy efficiency and regenerative capabilities. Numerical simulation is carried out using path control and 2DOF anti-swing of a hydraulic crane as a load case to illustrate a real world scenario. A comparison wi…
Position paper - progress towards standards in integrated (aerobic) MBR modelling.
2020
Membrane bioreactor (MBR) models are useful tools for both design and management. The system complexity is high due to the involved number of processes which can be clustered in biological and physical ones. Literature studies are present and need to be harmonized in order to gain insights from the different studies and allow system optimization by applying a control. This position paper aims at defining the current state of the art of the main integrated MBR models reported in the literature. On the basis of a modelling review, a standardized terminology is proposed to facilitate the further development and comparison of integrated membrane fouling models for aerobic MBRs. ispartof: WATER …