Aspects regarding the prediction of corrosion of earth electrodes in the soil of Timi?oara municipality Part II. Saline fog tests |
Author : Stefan PAVEL,Ioan-Bogdan PASCU,Bogdan-Ovidiu TARANU, Oana-Alexandra GRAD, Romeo NEGREA |
Abstract | Full Text |
Abstract :Corrosion prediction of galvanized steel ground electrodes in the soil of Timisoara |
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Infrared Spectrography. Opportunities, areas and limits of application |
Author : Claudiu JIPA, Mihai DIMA, Vlad IORDACHE |
Abstract | Full Text |
Abstract :The maximum performance of this procedure depends on the correct understanding of the phenomenon, both in capturing IR images and in their analysis and interpretation. In the case of mis-application or mis-interpretation, there are risks for determinations of over 150%. This paper aims to detail the principles of the method and to be a useful tool for specialists in choosing thermographyc equipment corresponding to the area of interest analyzed. |
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Increasing energy efficiency in wind power systems operating at variable wind speeds over time. Part II |
Author : Lucian CRISAN, Simona POPA-ALBU, Meda Alexandra LAZAR, Daniel BREBENARIU, Cristian MURARESCU, Marius DUDU, Ioan BORZA, Marius BABESCU |
Abstract | Full Text |
Abstract :This paper proposes a method of increasing the energy efficiency of a wind power system, SEE, consisting of a wind turbine, TV and a synchronous synchronous generator with permanent magnets, GSMP, at variable wind speeds over time. The maximum power of TV, PTV (?), is obtained when operating at the mechanical angular velocity, VUM, optimum, ?OPTIM, the value of which depends directly on the wind speed. Electricity obtained over time t from an EEA depends on the two basic functional sizes: 1) Wind velocity values, V, in the time interval ?t, and 2) VUM, ?, respectively its variation over time. The fundamental problem in achieving the maximum energy efficiency at time t is to correlate the current VUM value ? with the value of the wind speed at that time. By measuring two basic sizes: wind speed V and current VUM, ?, the possibility of capturing a maximum wind energy in the EEA from the MinAna-Dobrogea area is analyzed. To perform at the MPP maximum power point, the current VUM must be OPTIM. |
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The dynamic thermal behavior of a heat pump operating between 2 storage tanks |
Author : Florin IORDACHE, Alexandru DRAGHICI, Mugurel TALPIGA |
Abstract | Full Text |
Abstract :In the paper is proposed an approximate method of evaluation of the energy performance offered by a system that uses renewable sources by means of a vapor mechanical compression heat pump. Along with the energy balance of the heat pump, is presented also the non-stationary thermal balance of the source and consumer environments, each represented in the present work by a water storage tank, from which the heat pump extracts the thermal flux and respectively supplies heat flux (flow). Theoretical working relationships allow the dynamic evaluation of the energy performance of the system, which aids the selection of a suitable capacity for the heat pump, in concordance with the demand heat of the consumer. |
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Procedure for evaluating performance indicators for refrigeration machines or heat pumps |
Author : Florin IORDACHE, Alexandru DRAGHICI |
Abstract | Full Text |
Abstract :This paper presents a numerical procedure for evaluating the energetical indicators of the refrigeration systems with mechanical compression, that can be used to extract (EER) or to supply heat (COP) to the consumer. The procedure uses as input data the temperature values of the cold environment (where the frigorific evaporator is installed) and warm environment (surrounding the frigorific condenser). The electric and isentropic efficiencies of the compressor are also taken into account. Within the functional simulation developed in CoolPack software, the evaporator efficiency at isentropic compression is used as a fundamental energetical indicator. |
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Thermographic inspection for building diagnosis |
Author : Andrei PREDA, Lelia Letitia POPESCU, Stefan Razvan POPESCU |
Abstract | Full Text |
Abstract :Thermography (infrared thermal imaging) is one of the non-destructive methods by which surface temperature variations can be determined on the surface of a building. By this method one can exemplify, at one time, the heat loss through the surface of the building. Thermovision consists of scanning the building with infrared, using a special camera. This allows us to identify the hottest areas where the greatest heat loss occurs. On the basis of the information obtained, the optimal solutions for reducing energy losses can be established, resulting in a better environment for buildings and lower costs in terms of thermal energy, and not only. Thermal camera recordings are converted into color images. The range of colors and color intensity give us insights into temperature differences from the surface of the building under test. All of this creates an overview of the entire building, so construction specialists can make a fair interpretation and offer the most appropriate solution for the issue. |
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Determination of stresses the interface of a rigid eccentric footing, accounting for the effect of soil mechanical characteristics and footing geometrical parameters |
Author : Benayad Slimane, Kadri Fatima, Yousfi Aimen |
Abstract | Full Text |
Abstract :As footings are the most important elements in any construction, it seems judicious to dwell on the sizes that condition these dimensions, as well as soil quality on which these footings will be constructed, especially that they often subject to eccentric loads caused by catastrophic natural phenomena (earthquakes, land pressures, wind, etc. It is therefore important to know, with the largest possible approximation, stresses distribution under the footing, and therefore to what extent the structure can remain stable. The study presented herein examines stresses distribution at soil-footing interface for different combinations of soil properties, foundation geometry and applied load eccentricity using 2D finite element modeling. The FEM evaluation is accomplished by using COMSOL software program. The results prove importance and effect of these mechanical and geometrical characteristics on stress distribution at the interface while theoretical solutions strongly ignore some of them. |
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Transparent Concrete |
Author : Georgia Alexandra COVALEOV |
Abstract | Full Text |
Abstract :Reinforced concrete was invented and developed simultaneously by several people in the mid-nineteenth century. Besides versions "classical" fiber reinforced concrete (by using steel bars, whatever "style" of them), there are new ways to further concrete strength. Transparent concretes (translucent) is gaining much ground in the construction of the West Europe. "Light Transmitting Concrete" is a concrete-like product, which is translucent due to the mixture of fiber glass, plus a combination of finely divided crushed stone, cement and water. After the strengthening of composition, blocks of various shapes are obtained, with features of concrete and glass. Transparent concrete is a translucent material created by the combination of concrete and thousands of optical fiber wires acting as a filler. |
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Energy analysis regarding the dimensioning and evaluation of the energy performance of the installations using solar thermal collectors |
Author : Florin IORDACHE |
Abstract | Full Text |
Abstract :In the paper a relationship is established for assessing the degree of energy coverage of the heat demand for space heating or the preparation of hot water. Within this relationship we identify a series of 3 parameters of the energy configuration of the consumer - solar installation and also an important climatic energy indicator especially in terms of the location of the consumer location. |
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