The article presents a theoretical and experimental analysis that highlights how the employment of a hydrogen- methane mixture influences the variation of the fuel flow for wall-mounted boilers and also aims to evaluate whether fuel economy may be achieved. For a 28 kW condensing boiler, at 50/30 °C water outlet/inlet operating regime and for 2800 h functioning, 431 m3 of methane gas were saved when using a 23% hydrogen-methane combustible. Correspondingly, at 80/60 °C working regime 599.3 m3 of methane economy was achieved. The theoretical increasing of the combustible flow of 23,2% is validated by the value obtained experimentally of 22.84% respectively, when the mixture is utilized.

Keywords: hydrogen combustible; fuel savings

Obiectivul lucrarii este de a prezenta, aspecte referitoare la: coroziunea metalelor acoperite si neacoperite cu zinc in solul oraşului Timisoara (electrozi de impamantare a Instalatiei de Legare la Pamant aferenta Instalaţiilor Electrice din Constructii), analiza parametrilor de sol, prototipuri de electrozi, masuratori electrice, microbiologice si analiza de prognoza-predictie matematica, materiale si dictionare de termeni aferenti. Un alt aspect prezentat in acest material este efectuarea de măsuratori ale spectrului campului elecromagnetic oscilografiat al elementelor de metal acoperite si neacoperite cu zinc din sol.

Cuvinte cheie: electrod de impamantare, sol, legare la pamant, microbiologia solului

The objective of this paper is to present aspects related to: corrosion of metals covered, and not covered with zinc in the soil of Timișoara (grounding electrodes of a grounding installation related to Electrical Installations of Constructions), analysis of soil parameters, prototype electrodes, electrical, microbiological analysis and mathematical prognosis analysis-prediction, materials, and dictionaries of related terms. Another aspect presented in this material are the measurements related to the spectrum of the oscillograph electromagnetic field of the grounding electrodes, which are covered, and not covered with zinc.

Keywords: corrosion, ground electrode, soil, grounding, soil microbiology

In Glazed elements play an important role in total energy consumption of buildings. They significantly influence total energy consumption through energy consumption for heating and cooling, ventilation and lighting. To optimize these consumptions, the glazed elements must be treated taking into consideration several characteristics, namely: thermal transmittance, degree of transparency and solar factor. Moreover, the choice of glazed elements must be studied and calibrated by the type of building but also by location, from a climatic point of view. The purpose of this paper is to highlight the main characteristics of glazed elements and the ways in which these can be measured. The equipment and its operation are presented as well as examples of measurements performed on different types of glazed elements. Also, the paper presents a case study that includes the thermal balance performed on a building in Timisoara taking into account the characteristics of the measured glazed elements. In order to highlight their importance, a parametric study of the transmittance and the solar factor was performed, taking into account the investment costs, respectively, the cost over the life of the investment.

Keywords: U-value, g-value, low-e, glazed elements

Ventilarea incendiilor reprezinta o procedura activa de interventie care determina scaderea temperaturilor, concentratiilor produsilor de ardere si cresterea vizibilitatii pentru facilitarea interventiei pompierilor in scopul salvarii de vieti si de reducere a pagubelor materiale. In acest scop, a fost realizat un studiu bibliografic a cercetarilor experimentale si numerice initiate in domeniul ventilarii incendiilor. In urma consultarii studiilor s-a evidentiat eficienta ventilarii incendiilor pentru reducerea concentratiilor produsilor de ardere si a temperaturii maxime si cresterea vizibilitatii. De altfel, pentru cladirile inalte s-a confirmat ca ventilarea incendiului este puternic influentata de efectul de cos aparut din cauza diferentelor mari de nivel.

Cuvinte cheie: ventilation, fire, temperature, numerical modelling

Fire ventilation is an active intervention procedure that lowers temperatures, concentrations of combustion products and increases visibility to facilitate the intervention of firefighters for saving lives and reduce material damage. For this purpose, a bibliographic study of the experimental and numerical researches initiated in the field of fire ventilation was carried out. After consulting the studies, the efficiency of fire ventilation was highlighted for reducing the concentrations of combustion products and the maximum temperature and increasing visibility. Moreover, for high-rise buildings, it was confirmed that fire ventilation is strongly influenced by the stack effect caused by big level differences.

Keywords: ventilare, incendiu, temperatura, modelare numerică

Lucrarea de fata prezinta un sistem termic hibrid inovativ compus din captatoare solare, robinet de reglaj proportional, rezervor de acumulare si pompa de caldura conectate hidraulic in serie, pentru a satisfice necesarul de caldura al unei cladiri. Procedura evalueaza valoarea temperaturii de iesire a robinetului de reglaj, pentru a obtine temperatura proiectata la iesirea captatorilor solari, astfel incat energia acumulata peste zi in interiorul rezervorului de acumulare, sa satisfaca necesarul energetic la vaporizatorul pompei de caldura pentru a putea genera la condensator toata energia necesara pentru incalzire. Ecuatiile matematice sunt astfel propuse, precum si un algoritm de functionare, pentru a calcula temperatura de iesire a robinetului de reglaj in schema hidraulica propusa. In capitolul de concluzii, sunt prezentate avantajele acestui algoritm, prin plotarea rezultatelor simulate in diverse conditii climatice si de necesar termic de incalzire.

Cuvinte cheie: sistem hibrid, captatoare solare, necesar termic

The paper presents a novel hybrid heating system composed by solar collectors, mixing valve, heat storage tank and heat pump hydraulically connected in series, to satisfy the heating demand of a building. The procedure evaluates the temperature set-point value of the mixing valve, to obtain the design output temperature of solar collector, thereby the energy accumulated over the day inside storage tank should satisfy required heat pump evaporator energy to deliver at its condenser building demand. Mathematical equations are thus proposed and algorithm to establish mixing valve temperature set-point is presented. In the conclusion of the paper are described advantages of this algorithm based on plotted simulation results in several weather conditions and building heating demands.

Keywords: hybrid system, solar collectors, thermal requirement

Lucrarea constituie o contributie la dezvoltarea tehnicii fabricarii unui beton geopolimeric pe baza de cenușa zburatoare si zgura de furnal cu rezistenta la compresiune crescuta pana la 73 MPa si rezistenta la incovoiere atingand 12,1 MPa (după 180 zile de intarire) prin adaosul unor mici cantitati de nanosilica (20-50 nm) si praf de otel (1-5 μm) captat din gazele evacuate din cuptorul electric cu arc. Originalitatea lucrarii consta in combinarea tehnicii producerii betonului prin utilizarea produselor secundare industriale aluminosilicatice (cenusa si zgura) cu adaosul unor nano sau microparticule in scopul cresterii semnificative a rezistentei mecanice a betonului geopolimeric.

Cuvinte cheie: beton geopolimeric, cenusa zburatoare, zgura de furnal, nanosilica, praf de otel, rezistența mecanica.

The paper is a contribution to developing the manufacturing technique of fly ash and blast furnace slag-geopolymer concrete with compressive strength increased up to 73 MPa and flexural strength reaching 12.1 MPa (after 180 days of curing) by adding low amounts of nanosilica (20-50 nm) and steel dust (1-5 μm) captured from electric arc furnace exhaust gases. The originality of the work consists in combining the concrete production technique by using alumino-silicate industrial by-products (ash and slag) with the addition of nano or micro-particles in order to significantly increase the mechanical strength of geopolymer concrete.

Keywords: concrete, fly ash, blast furnace slag, steel dust, mechanical strength.

In this paper we aim to analyse a current issue such as “Building Information Modelling” or modelling information in construction from a project manager's point of view. BIM is a digital tool for creating and using coordinated information in a single construction project. Generally, this model is defined as a 3D model from which the information required for each design or execution phase is extracted. 4D dimension refers to time-related information, 5D to cost information, 6D to sustainability, 7D to facility management, 8D to safety during design and building, 9D to "Lean" building concept and 10D to construction industrialization. The authors suggest the transformation of BIM 9D from Building Lean into BIM 9D project “aesthetics and visualization”.