Search results for "Energy System"
showing 10 items of 46 documents
Exergoeconomic analysis as a tool for supporting the design and operation of multiple chiller systems in air conditioning applications.
2019
Multiple-Chillers systems represent viable solutions for medium/large-scale air conditioning applications. In these systems, however, design and energy savings are highly affected by the configuration and operation strategies adopted. For instance, when considering multiple chillers of same size, “symmetric” or “sequential” load sharing strategies are two viable options. Conversely, when considering chillers of different sizes, a wide combination of chillers cooling capacities may be adopted. It is apparent that an integrated analysis of the design and operation of these systems should be carried out in order to achieve profitable energy saving. With this respect, Exergoeconomics, which res…
Environmental Assessment of a Hybrid Energy System Supporting a Smart Polygeneration Micro-grid
2022
To support the global transition towards a climate-neutral economy by 2050, countries all over the world are implementing low carbon and energy effi ciency policies. This is leading to a rapid increase in the installations of distributed generation technologies. A hybrid system consisting of two or more energy sources could provide a more reliable supply of energy and mitigate storage require ments. In this context, this paper develops an environmental early analysis by the employment of a simplified Life Cycle Assessment approach. The above mentioned approach is used to investigate the environmental performances of the hybrid energy system of the smart polygeneration micro-grid of the Univ…
Analysis of the effects of climate change on the energy and environmental performance of a building with and without onsite generation from renewable…
2020
Climate Change is a priority, due to the large variety of implications and importance that it may cause in the next decades. In this context, the building sector is a significant contributor to greenhouse gas emissions. For this reason, buildings should be designed in such a way that they are responsible for fewer GHG emissions. In this context, the paper analyses the potential impact of climate change on the energy performances of buildings, with and without onsite generation from renewable energy, using a prototype building located in Messina (Italy) as case study. The analysis is based on Intergovernmental Panel on Climate Change RCP scenarios and the results confirm the already known ov…
Assessment of the renewable energy production in a historical building for a touristic intended use: a technical-economic feasibility study
2011
This column deals about a study based on technical and economical feasibility of a combination of technologies and systems for energy production concerning electric, heating and cooling to install on a building in the historic centre of a Sicilian city (Italy). After a functional review and an energetic evaluation, the building will have a hotel destination. A first evaluation, made on a model set with the geometrical, thermo-physical and climatic data both of the building and the place, allowed to make a dynamic simulation to define the energetic monthly needs. The evaluation has been done considering different solutions and technologies. With the collected data we supposed a first sizing …
The interaction between intermittent renewable energy and the electricity, heating and transport sectors
2012
In a global perspective, it is essential that the world transfers from fossil fuels to renewable energy sources in order to minimise climate change effects. As a part of such transition energy savings are also important, as they can decrease production costs effectively. The nature of such a change is that it has to be implemented on a local level. Energy saving technologies are placed with the demand decrease and renewable energy is typically distributed where the resources are. In some parts of the world, energy savings have resulted in a stabilisation of the energy demands, however in the world as such, demands are still increasing in buildings, transport and industry. Although the deman…
ECO-PROFILES OF INNOVATIVE ENERGY SYSTEMS FOR DOMESTIC AND RESIDENTIAL APPLICATIONS
2015
The exponential growth of distributed generation systems (mainly from solar energy through the use of photovoltaic) and the new release on energy markets of new generation technologies, with smaller dimension, are pushing towards rethinking energy systems. "Smart buildings" with the capacity to produce, store and manage flow of information's and energy will become the milestone of the future distribution networks (smart buildings to smart grid). The goal of this study is to evaluate the ecoprofile of 1 kWh of electricity, selected as a functional unit, generated by microcogenerator fuel cells as SOFC. The analysis was performed using the Life Cycle Assessment methodology, which allows to co…
DC Grids for Supporting AC Power System during Failure Events: Experimental Testing of a Urban Case Study
2022
AC power systems and their devices can be subjected to different failure events due to thermal, environmental, and aging phenomena. In this context, DC grids intervention could mitigate customers black-out by adequately controlling their internal resources (renewable generators and storage systems). In this paper, failure events concerning HV/MV transformer are considered. Possible actions to support the AC grid to avoid interruption in load areas are analyzed and experimentally validated. Tests campaigns are carried out taking advantage of a research nanogrid infrastructure available at ENEA Centre of Portici. It consists of indoor equipment able to emulate actual generation, load and stor…
A linear generator for a waveroller power device
2017
In this paper experimental tests on a small scale tubular linear generator to be applied to wave rollers device are presented. A reduced scale of gnerator is presented and experimental results obtained in on test bench are shown. Experimental waveforms of current and voltage are recorded. Simulation results are compared to the experimental ones in order to validate the mathematical models used.
Oxygen uptake kinetics and energy system's contribution around maximal lactate steady state swimming intensity
2017
Made available in DSpace on 2018-11-26T17:20:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-28 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Ministry of Education of Brazil The purpose of this study was to examine the oxygen uptake ((V) over dotO(2)) kinetics and the energy systems' contribution at 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS) swimming intensity. Ten elite female swimmers performed three-to-five 30 min submaximal constant swimming bouts at imposed paces for the determination of the swimming velocity (v) at 100% MLSS based on a 7 x 200 m intermittent incremental protocol until voluntary exhaustion to find the v associated…
Numerical and experimental investigation of a cross-flow water turbine
2016
ABSTRACTA numerical and experimental study was carried out for validation of a previously proposed design criterion for a cross-flow turbine and a new semi-empirical formula linking inlet velocity to inlet pressure. An experimental test stand was designed to conduct a series of experiments and to measure the efficiency of the turbine designed based on the proposed criterion. The experimental efficiency was compared to that from numerical simulations performed using a RANS model with a shear stress transport (SST) turbulence closure. The proposed semi-empirical velocity formula was also validated against the numerical solutions for cross-flow turbines with different geometries and boundary c…