Search results for "construct"
showing 10 items of 3723 documents
Smart renewable generation for an islanded system. Technical and economic issues of future scenarios
2012
The subject addressed in this paper is the analytical study of the transition of an energy generation system for a real MV/LV distribution system from one that is “fuel-based” to a distributed and smart “renewables-based” system. The paper outlines both the technical and the economic issues related to such a transition from one type of system to the other. The study is carried out for a real islanded network located in the Island of Pantelleria (Mediterranean Sea). The results obtained are presented and discussed, putting into evidence the technical, environmental and economic benefits of using smart technologies and renewable energy sources.
Single thermal zone balance solved by Transfer Function Method
2005
We present an algorithm that uses the Z-transform operator to face the problem of heat transmission in a single thermal zone composed by multilayered walls. The method is very flexible and could be adopted to calculate the transfer function coefficients able to simulate the thermal behaviour of a room in free floating. Knowing the transfer function coefficients, it is possible to simulate the dynamic profile of each inner surfaces temperature and furthermore of the inner air temperature. The proposed algorithm is fully described granting maximum clarity. The explicitness of all steps of the calculus make possible the definition of a method that is able to vary all of the calculus parameters…
A cellular automaton based model simulating HVAC fluid and heat transport in a building. Modeling approach and comparison with experimental results
2010
A discrete model characterizing heat and fluid flow in connection with thermal fluxes in a building is described and tested against experiment in this contribution. The model, based on a cellular automaton approach, relies on a set of a few quite simple rules and parameters in order to simulate the dynamic evolution of temperatures and energy flows in any water or brine based thermal energy distribution network in a building or system. Using an easy-to-record input, such as the instantaneous electrical power demand of the heating or cooling system, our model predicts time varying temperatures in characteristic spots and the related enthalpy flows whose simulation usually requires heavy comp…
Combination of modal responses consistent with seismic input representation
2004
The well-known modal superposition method for the evaluation of seismic response by the complete quadratic modal combination rule (CQC) is revisited. The most widely used version of the CQC rule utilizes correlation coefficients derived for white-noise excitation and neglects the influence of peak factor variation on the response. Here a simplified procedure for evaluation of correlation coefficients and peak factors consistent with the power spectral density of seismic excitation is proposed. The procedure is based on an approximate analytic expression for direct evaluation of the power spectral density of the excitation consistent with any prefixed response spectrum, and the evaluation of…
Applicability of over-coring technique to loaded RC columns
2014
Stress determination is a very important step in the assessment of the safety of existing reinforced concrete structures. In rock mechanic this goal is achieved with the over-coring technique. The main idea behind such a technique is to isolate a material sample from the stress field in the surrounding mass and monitor its re-equilibrium deformation response. If the materials remains elastic, and elastic properties are known, stresses may be obtained from the corresponding measured strains. The goal of this paper is to evaluate if the over-coring technique is applicable to reinforced concrete members. The results of an experimental investigation on the behaviour of compressed concrete colum…
A novel solar trigeneration system integrating PVT (photovoltaic/thermal collectors) and SW (seawater) desalination: Dynamic simulation and economic …
2014
Abstract The paper investigates the integration of renewable energy sources and water systems, presenting a novel solar system producing simultaneously: electrical energy, thermal energy, cooling energy and domestic water. Such system is designed for small communities in European Mediterranean countries, rich in renewable sources and poor in fossil fuels and water resources. The polygeneration system under analysis includes PVT (photovoltaic/thermal solar collectors), a MED (multi-effect distillation) system for SW (seawater) desalination, a single-stage LiBr–H2O ACH (absorption chiller) and additional components, such as storage tanks, AHs (auxiliary heaters) and BOP (balance of plant) dev…
A comprehensive tool for efficient design and operation of polygeneration-based energy μgrids serving a cluster of buildings. Part I: Description of …
2013
Polygeneration systems with thermal energy storage represent promising solutions to achieve energy saving and emissions reduction in the civil sector. The definition of customer-oriented design and operation strategies represents a most challenging task, in order to maximize the profitability and make the investment attractive. A large potential is often recognized for the installation of centralized plants serving a cluster of buildings located over a small area; in such cases the design problem becomes extremely complex and the analyst needs reliable instruments to identify the optimal solution. This paper in two parts presents a scientific tool for the optimization of design and operatio…
Stability analysis of clay brick masonry columns: numerical aspects and modelling strategies
2014
Stability analysis of masonry piers and columns is one of the most frequently treated subjects in the field of structural engineering. This attention is probably due to the challenge to solving the problem including different effects, which play an important role in evaluating the response of eccentrically-loaded columns. In this connection, accurate stability analysis of masonry piers and columns has to take into account the non-linear stress–strain law of masonry in compression, the limited tensile strength, the induced slenderness due to crack formation and geometrical non-linearity. Different theoretical models and numerical approaches were developed in the past to analyze the combined …
The construction of knowledge from the scientific literature about the theme seaport performance evaluation
2015
Purpose – The purpose of this paper is to know what scientific literature presents about the theme evaluation of seaport performance, thus enabling the construction of knowledge in the researchers and the identification of gaps in the research that will lead to advances in the area from the identification of the characteristics of a portfolio of relevant international publications. Design/methodology/approach – From the basic philosophical (constructivism), of the kind strategy (research-action) and the method used for the accomplishment of such strategy (structured process knowledge development process – constructivist (ProKnow-C)) the current research has a qualitative approach. Findings…
The experimental research strategy of the endmilled aluminum alloys
2017
In this paper, the most important aspects of the research methodology of the resulted surface quality by aluminum alloys endmilling, are presented. The first part of the paper includes a short presentation of the cutting processes aluminum alloys evolution. In the second part, the research problem was defined by setting a fundamental objective and identifying the specific objectives which contribute to achieve the fundamental objective. In this context an experimental study, was performed, starting with the organization and conducting the endmilling process, in which the cutting regime were established, then the characteristic measured parameters were determined, so that the research factor…