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E-Journal № 1 2007

"PROBLEMS OF THE REGIONAL ENERGETICS"

CONTENTS

1 THE ANALYSIS OF TENDENCIES OF CHANGE OF INDICATORS OF ENERGY SECURITY OF MOLDOVA DURING 1990-2005
Authors: Bicova E.V.,
  Abstract: The summary. The change of indicators of energy security with addition of results of calculations for 2005 is analyses in the article. Tendencies of change of an integrated estimation of all system of indicators and necessary actions on improvement of a situation are described.
  Keywords: energy security, an integrated estimation.
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2 VEGETATIVE RAW MATERIAL FOR RECEPTION OF THE PETROLEUM PRODUCTS AND ENERGY SECURITY OF REPUBLIC OF MOLDOVA
Authors: G. Duka, A.Krachune
  Abstract: The problem of increase of energy security of Republic Moldova is examined due to use of own power resources. Application of a biodiesel engine, bioethanol in mixes with traditional kinds of fuel (diesel fuel and gasoline) is possible without updating a design of existing engines of internal combustion and can be economic for agriculture and on transport. Results of experiments on definition износоустойчивости lubricants received of vegetative raw material of local manufacture are resulted. Use of bioethanol as the additive to gasoline will lower his{its} cost, will reduce consumption of gasoline to 15-20 % and will allow to reduce considerably harmful emissions in an atmosphere, ecological safety that will favorably be reflected on health of the population will be raised. Manufacture of lubricants with use рапсового oils also will allow to receive serious economic benefit.
  Keywords: energy security, power cultures, biodiesel engine, bioethanol
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3 ADVANCED COMPUTATIONALMETHODS FOR COMPLEX SIMULATION OF THERMAL PROCESSES IN POWER ENGINEERING
Authors: R.V. Filkoski, I.J.Petrovski
  Abstract: The overall frame and principal steps of complex numerical modelling of thermal processes in power boiler furnaces on pulverised coal with tangential disposition of the burners are presented in the paper. Computational fluid dynamics (CFD) technique is used as a tool to perform comprehensive thermal analysis in two test cases. The methodology for creation of three-dimensional models of boiler furnaces is briefly described. Standard steady k- model is employed for description of the turbulent flow. The coupling of continuity and momentum is achieved by the SIMPLEC method. Coal combustion is modelled by the mixture fraction/probability density function approach for the reaction chemistry, with equilibrium assumption applied for description of the system chemistry. Thermal radiation is computed by means of the simplified P-N model, based on expansion of the radiation intensity into an orthogonal series of spherical harmonics.Comparison between the simulation predictions and available site measurements leads to a conclusion that the model produces realistic insight into the furnace processes. Qualitative agreement of the results indicates reasonability of the calculations and validates the employed sub-models. The described test cases and other experiences with CFD modelling stress the advantages over a purely field data study, such as the ability to quickly and cheaply analyse a variety of design options without actually modifying the object and the availability of significantly more data to interpret the results.
  Keywords: pulverised coal-fired boiler, CFD modelling, combustion, thermal radiation, heat transfer
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4 SYNCHRONOUS OPERATION OF FIVE-PHASE CONVERTERS IN LINEAR MODULATION REGION
Authors: V.Oleschuk, F.Profumo, Alexandr Sizov , A.Tenconi, Evgeni Yaroshenko ,
  Abstract: This paper presents results of the development and application of algorithms of synchronized pulsewidth modulation (PWM) for control of five-phase voltage source inverters. Simulations give the behavior of five-phase power conversion systems with algorithms of continuous and discontinuous synchronized PWM.
  Keywords: multiphase modulated inverter, five-phase load, phase voltage synchronization.
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5 DYNAMIC MODEL “ELECTRICITY CONSUMPTION - GDP” FOR REPUBLIC OF MOLDOVA
Authors: Sit B.M.,
  Abstract: The article is devoted to the development of econometric models of electricity consumption in Republic of Moldova with the purpose of definition of potential possibilities of GPD influence on electricity consumption processes.In this paper, we examine the causal relationship between the per capita electricity consumption and the per capita GDP for Republic of Moldova using VAR model. Our results show that there is bidirectional causality from per capita GDP to per capita electricity consumption and vice versa. The finding has significant implications from the point of view of energy conservation, emission reduction and economic development.
  Keywords: Clasificarea JEL: Q41,Q43.Cuvinte cheie: modele econometrice, consumul de energie electrică.
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6 THE SOLAR RADIATION CHARACTERISTICS ON THE TERRITORY OF THE REPUBLIC OF MOLDOVA
Authors: Gucu Corina
  Abstract: In the work are given the necessary for technical and economic accounts of solar energy using installations characteristics of solar radiation: the total radiation flow intensity, the optimum inclination angle of the receiving surface and the available energy quantity for a fixed surface and mobile on one and after two coordinates surfaces.
  Keywords: solar radiation intensity, optimum inclination angle.
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7 COOLING SYSTEMS OF MILK, FRUIT AND VEGETABLES STORAGE WITH LOW CONSUMPTION OF ENERGY
Authors: L. Volkonovich, M. Kiorsak, , Turkuman L., A. Volkonovich, D. Oprea, V. Rotari, V. Slipenchi
  Abstract: Article is devoted to use of a natural cold for cooling milk and fruit and vegetables storage. The analysis of the block diagrams, description of storehouses and the curves of temperature and air humidity changes for various types of cooling systems are given; the analysis of quality of vegetables and fruit and energy expenses per unit of production are done, which prove the efficiency of the offered systems.
  Keywords: a natural cold, milk cooling systems and fruit and vegetables storage, block diagrams analysis, temperature and humidity of air curve changes.
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8 EFFICIENCY OF THE USE OF HEAT PUMPS ON THE CHP PLANTS
Authors: Juravliov A.A., Sit M.L., A.L. Zubatii,Poponova O.B., Sit B.M., Timcenko D.V., Institute of Power Engineering of the ASM
  Abstract: Abstract. The work is dedicated to the calculus of the efficiency of the use of heat pumps on the CHP plants. There are presented the interdependences between the pay-back period and NPV of heat pump and the price of 1 kWt of thermal power of heat pump and of the tariff of electricity.
  Keywords: Heat pumps, efficiency of heat pumps.
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