Volume 3, No. 11 (2005)

NEW DEFINITIONS AND FLUID-ENERGETICS CORELATIONS

BENCHE VICTOR, HUMINIC ANGEL, HUMINIC GABRIELA

Having as reference the image of the Euler-D’Alembert stream-tube, the paper deals with the motion of real fluids from the energetics point of view, being proposed the energetic stream-tube concept as a spatial representation of the power resource for a flowing fluid. In this way, there can be performed optimisations of the hydraulic circuits.

THE RETECHNOLOGIZATION OF ROSIORI 400/220 kV POWER STATION – AN IMPORTANT ASPECT OF THE INTERNATIONAL INTERCONNECTION REGARDING ROMANIA’S INTEGRATION INTO THE UNION FOR THE COORDINATION OF TRANSMISSION OF ELECTRICITY – U.C.T.E.

FITA DANIEL

This paper presents the importance of the retechnologization of Rosiosi 400/220 kV power station from Satu Mare county – an important aspect of the international interconnection regarding Romania’s integration in the Union for the Coordination of Transmission of Energy – U.C.T.E. and, consequently, Romania’s integration in the European Union.

THE ANALYSIS OF THE NON-SINUSOIDAL STATE IN PUBLIC DISTRIBUTION NETWORKS

GEORGESCU GHEORGHE, VARVARA VIOREL

It is unanimously accepted that, strictly interpreting the facts, the appearance of the non-sinusoidal state in public distribution networks can not be avoid and we must deal with it. Very often the existence of waveform pollution is detected following casualties, like the destruction of power factor capacitors. In present, the main harmonic sources in public distribution networks are represented by the low power converters used as devices in the TV-sets, computers, public lighting, a.s.o. With different meters the non-sinusoidal state can be identified and thus can be suggested methods or decisions concerning the optimal development and exploitation of the medium and low voltage distribution networks, which must be a result of a multi criteria optimization process.

THEORETIC ASPECTS REGARDING WATER DISTRIBUTION NETWORKS RELIABILITY

GRIGORE ROXANA

The paper presents theoretic considerations about the reliability of water networks. While reliability of other technical systems depends only on the network configuration and the failure rate of its elements, the water network (the water distribution system) has the request to assure the network hydraulic parameters. There are a number of techniques developed for evaluating system reliability with complex configuration. In this paper is presented cut-set method used for calculation of water distribution network reliability

NUMERICAL TECHNIQUE FOR VERIFICATION OF SUCCESS STATES IN THE NETWORK

HAZI GHEORGHE, HAZI ANETA

This paper analyzes efficiency of two techniques for verification of success states in the network. The first method verifies existence some links in the network using o successive drop out method of nodes until it is generated o link between these nodes. The second method is based on the successive connection of nodes to the trees which have as root source nodes or system nodes. There are compared these methods and are applied for a test network.

NATURAL GAS DISTRIBUTION THROUGH POLYETHYLENE PIPELINES. REPARTITION PIPELINES CAPACITY OF TAKING OVER FLOW VARIATIONS

TRIFAN C., ALBULESCU M., SCARLAT E., IONESCU I.

This paper proposes a genuine mathematical model for the study of the non-steady phenomena which characterize the slow motion through gas pipelines due to the change of gas inflow at the consumer. The software elaborated on the basis of this mathematical model allows the determination of the duration of the two stationary regimes between which the non-steady movement takes place

NATURAL GAS TRANSPORT THROUGH MAIN PIPELINES. THE INFLUENCE OF DIGGING-IN ON GASES PRESSURE AND TEMPERATURE IN FINAL EDGE OF PIPELINE

TRIFAN C., ALBULESCU M., SCARLAT E., IONESCU I.

This paper proposes a genuine mathematical model which takes into account all gas dynamic parameters that are involved in the steady state gas transport process through the pipeline. In order to notice the influence of pipelines digging – in on pressure and temperature according to the medium temperature variation, the paper presents variation of the gases pressure and temperature at the final edge of the pipeline.