86,607 research outputs found
Sustainable airports and NZEB: The real case of Rome International Airport
No full textThe paper shows and analyzes the energy efficiency solutions adopted to renew the terminal T3 of Rome International Airport at Fiumicino 'Leonardo da Vinci'. Such solutions put together the top-of-the-market energy technologies with the most innovative architectures and materials to renovate an old terminal transforming it into a Nearly Zero Energy Building (NZEB). For the new forepart of the terminal and for the new boarding area 'F', now under construction, a dynamic energy simulation has been performed using a software provided by the US Department of Energy (DOE) named Energy Plus, and its interface Design Builder. The tool makes possible to calculate the energy consumption of the two buildings and to assess the design in order to maximize energy efficiency and sustainability. The main results of the energy analysis are reported after detailing the case study
Thermal Comfort and Energy Saving Optimization for HVAC Systems with Night Ventilation Cooling
No full textA significant part of the primary energy demand in industrialized countries is due to space heating and cooling in buildings. Furthermore especially in Europe, the use of HVAC systems is becoming highly popular, thus, the development of efficient cooling techniques is a very important research task to prevent an uncontrolled energy consumption increase. Night ventilation is a passive cooling technique that can significantly reduce the cooling loads and energy requirements, but a trade off must be made between energy cost savings and zone thermal comfort. The Multi-Objective Genetic Algorithms (MOGA) optimizations tools can be helpful in developing optimized cooling systems while maintaining comfort conditions constraints
Surface measurements of radio antenna panels with white-light interferometry
No full textTypical radio telescopes have the primary reflector surface which is composed of several single panels that have dimensions of a meter a side. The manufacturing of these radio panels yield a micrometric precision over the volume on the single panel, hence the surface roughness of the panels can be measured with very high accuracy by means of the low coherence interferometry (LCI) technique which reaches micrometric spatial and depth resolution and has the advantage of being contact-less. We have developed a multi-channel partially coherent light interferometer to realize non contact 3D surface topography. The technique is based on the LCI principle, for which a bi-dimensional sensor - a CMOS - has been developed to directly acquire images. Tri-dimensional measures are recovered with a single scanning along the depth direction in a millimetric range, and every single pixel of the bi-dimensional sensor measures a point on the object, this allows a fast analysis in real time on square centimeter areas. In this paper we show the results obtained by applying the LCI technique method to analyze the surface roughness of the panels of a large radio antenna of 64 m of width and used for astronomical observations at 100 GHz; by measuring their 3D structure at micrometric resolution it is possible to verify their fabrication errors
Utilizzo di Codici Commerciali per lo Studio dello Scambio Termico in Geometrie Periodiche
No full textAnalisi dello Scambio termico e di Massa in un Componente Edilizio a Raffrescamento Evaporativo
No full textDepth Calibrations of a 2D-CMOS-Based Partially Coherent Light Interferometer
No full textThis work concerns the development of a 3D measuring system able to realize noncontact surface topography with millimetric depth-range and micrometric resolutions both in the spatial and depth axes. The optical concept is based on the well known low coherence interferometry (LCI) technique. The most widespread set-up of such technique is that of measuring only a point at a time with a 2D scanning system that permits the measure on an area. The novel concept of our instrument is based on the use of a 2D sensor (CMOS), where every single pixel measures a point on the object and this permits a fast analysis on square centimeters areas without the need for any precise (and expensive) scanning system. We present here accurate depth calibration which shows the potentiality of this instrument
Thermal Comfort and Energy Saving Optimization for HVAC Systems with Night Ventilation Cooling
No full textSummary: A significant part of the primary energy demand in industrialized countries is due to space heating and cooling in buildings. Furthermore especially in Europe, the use of HVAC systems is becoming highly popular, thus, the development of efficient cooling techniques is a very important research task to prevent an uncontrolled energy consumption increase. Night ventilation is a passive cooling technique that can significantly reduce the cooling loads and energy requirements, but a trade off must be made between energy cost savings and zone thermal comfort. The Multi-Objective Genetic Algorithms (MOGA) optimizations tools can be helpful in developing optimized cooling systems while maintaining comfort conditions constraints
Reliability-based optimization for energy refurbishment of a social housing building
No full textThis paper investigates the influence of a stochastic variation of economic parameters in an optimization loop applied to a refurbished social housing building. Usually energy and economic optimization procedures rely on the results of an underlying numerical deterministic model which influences both energy gains and economic figures. However the results are influenced by parameters, which cannot be known in advance especially if they can change during a long period, such as fuels cost and economic indexes. To overcome the problem in this paper a robust approach for building refurbishment optimization has been adopted. Robust optimization considers a stochastic variation of parameters looking for solutions that are not only optimal but also robust, that is the optimal solutions maintain the optimality also for a range of the input parameters. The considered building represents a social house, and the energy reduction measures involve the application of internal insulation layers to the walls and the replacement of existing windows with more efficient ones
Multi-Objective Shape Optimization for Heat Exchanger Modules
No full textIn this article we present our approach for the multi-objective shape optimization of heat ex-changer modules. The first problem, of fundamental nature, describes a procedure for the geometric parameterization and multi-objective shape optimi-zation of two-dimensional periodic wavy channels. The geometry of the channel is parameterized either by means of linear-piecewise profiles, or by nonuni-form rational B-splines. The second case, of indus-trial interest, illustrates the development of an automatic method for the design of small gas tur-bine recuperators. For both problems the two objec-tives considered are the maximization of heat transfer rate and the minimization of friction factor, with the additional objective of minimization of heat transfer surface for the recuperator module. Since there is no single optimum to be found, we use a multi-objective genetic algorithm and the so-called Pareto dominance concept, both readily available in the modeFRONTIER optimization package. The results obtained are very encouraging, and the procedure described can be applied, in prin-ciple, to even more complex problems
Multi-objective Optimization for Problems Involving Convective Heat Transfer
No full textIn this chapter, focused on Computational Fluid Dynamics (CFD)-
based optimization for problems involving convective heat transfer, we present
our approach for the multi-objective shape optimization of periodic wavy
channels, representative of the repeating module of many heat exchangers.
The first problem is of fundamental nature and considers the geometric
parametrization and shape optimization of two- and three-dimensional periodic
wavy channels. The geometry of the channel is parametrized either by
means of linear-piecewise profiles or by non-uniform rational B-splines. The
second case, of industrial interest, illustrates the development and application
of an automatic method for the design of gas turbine recuperators.
After a literature review of shape optimization in heat transfer, we describe
in detail both aforementioned problems in terms of physical assumptions and
mathematical formulation. In the numerical methods section we indicate the
CFD codes used and describe the implementation of periodic boundary conditions.
Thereafter in the geometry parametrization section, we illustrate the
different types of numerical geometry representation used in the two problems,
and the corresponding definition of the design variables whose variation
leads to different shapes of the computational domain.
After a comprehensive classification and description of optimization methods
and algorithms, we present the results obtained for the two different
cases. For both problems the objectives considered are the maximization of
heat transfer rate and the minimization of friction factor, with the additional
objective of minimization of heat transfer surface for the recuperator module
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