Marius Constantin POPESCU


34-24 ASUPRA IMPORTANȚEI UNUI CRITERIU DE PROIECTARE A AMENAJĂRILOR HIDROENERGETICE

THE IMPORTANCE OF A DESIGN CRITERION
OF HYDROENERGY FACILITIES
The paper analyses the problem of the historical data on the periods of drought as a criterion of commercial contracts establishment, in accord with the hydropower design considerations. Even the insured flows statistics represents an major criterion of the plants design, the commercial contracts are established between economic entities, usually, having in their property more than one hydropower plant and of different capabilities, then the influence of the criterion requires a more subtle and complex analysis. The hydrological natural conditions require an operating graph for each hydroelectric plant. For some plants, the operation graph is corrected by the National Energy Dispatcher, in accord to the momentary energy market balancing requirements. The main owner of hydropower plants in Romania is the national company Hidroelectrica S.A. Its hydropower plants have different characteristics, depending on the installed power, geographic location, storage capacity and appurtenance to the list of plants for which the National Power Dispatcher has pre-emption. In this condition, the company has a range of flexibility, compared to other providers of electrical energy from hydraulic source. However, the restrictions imposed by the national dispatcher are severe enough in some dry periods, so the company has significant supply constraints. The paper analyses a practical situation for a period of time when the meteorological condition restriction the company operation. There will be demonstrated the level of restriction and the options for exploiting the production capacities, in order to not jeopardize the
safe operation of the National Energy System, and, in the same time, to cause minimum losses to the contractual partners.
Key words: design, layout, statistical data
Cuvinte cheie: amenajări, proiectare, date statistice

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34-14 ANALIZA PERFORMANŢELOR REALIZATE DE O CENTRALĂ FOTOVOLTAICĂ PENTRU O PERIOADĂ DETERMINATĂ DE TIMP

ANALYSIS OF A PHOTOVOLTAIC CENTER FOR
A PERIOD DETERMINED TIME
The paper describes the main methods to identify the parameters’
values over a time period for a photovoltaic plant, in order to highlight the
eventual equipment’s dysfunctions. For a real example of parameters
computation, there are made the following selections: the meteorological and
climatologic parameters are for a location from Romania, having latitude
44014’7”N and longitude 28033’19; the general characteristics of the apparatus
and equipment are selected from the providers catalogues; as the period of
time is selected a special period, June 2014 – May 2015, characterized by a
reduced sunlight, with consequently reduced solar radiation provided for the
photovoltaic collectors. For statistic computations there are utilized data
obtained from The National Institute of Meteorology (INM) for a period of 10
years.
Key words: photovoltaic plant, measurements, analysis
Cuvinte cheie:centrală fotovoltaică, măsurători, analiză

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32-8 STUDII PRIVIND STABILITATEA STATORULUI HIDROGENERATOARELOR

HYDROGENERATOR STATOR STABILITY STUDY

 

The paper analyses the hydro generators stator stability, based on the problems that occurred during the operation of the Romanian power plants. In order to highlight the  stator components role in these problems, it is analysed the stability of the stator housing and hydro operation found in samples and tests hydro Power Plant No. 1 hydropower from Great River Retezat, where the curvature of the stator creates vibration and instability in operation. The stability of the stator in this case can be obtained by an adequate construction of the building system of the winding heads to prevent any movement of the coils during operation of the hydro. Hydro generator stator is conditional stability dynamic stability of the metal housing because the stator housing design and construction of a great height without adequate consolidation creates problems of vibration and dynamic stability housing.

 

Key words: hydro generator, vibrations, numerical tests

Cuvinte cheie: hidrogenerator, vibrații, teste numerice

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29-66 MODELAREA SISTEMULUI DE RĂCIRE A ETANŞĂRILOR POMPELOR PRINCIPALE DIN CIRCUITUL PRIMAR DE TRANSPORT AL CĂLDURII LA CNE CERNAVODĂ

CNE CERNAVODA NUCLEAR POWER PLANT PRIMARY
HEAT TRANSPORT PUMPS GLAND SEAL
COOLING SYSTEM MODEL
Primary Heat Transport Pumps Gland Seal Cooling System scope is to
provide a high pressure D2O cooling flow to the primary heat transport pumps
seals. The system safety function is to maintain Primary Heat Transport System
pressure boundary integrity and to prevent radioactivity releases. In order to
monitor the seal operation and to warn of a possible malfunction or failure, the
papers propose an operation model, based on an electric-hydraulics similarity.
Keywords: pumps, gland seal, mathematical model, electric-hydraulics
similarity
Cuvinte cheie: pompe, presgarnitură, model matematic, similitudine
electric hidraulică

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