Volume 3, No. 11 (2005)
Articles
IMPROVING OF MOTOR VEHICLE ENERGETIC BY A HYDRAULIC RECOVERY-STORAGE OF THE VARIABLE MOVEMENT ENERGY
BENCHE VICTOR, UNGUREANU VIRGIL-BARBU
The work analyses the feasibility for energy recovery and storage of the horizontal and variable linear or curvilinear movement of the motor vehicles, based on the hydraulic schemas proposed by the authors, containing a reservoir of liquid “added” and hydraulic units-pressure multipliers, composed by linear or rotating motors, piston pumps and gas-loaded accumulators. There are elaborated relations for calculus and defined a relevant energetic indicator, illustrating the study by a numerical application.
A POSSIBLE ENERGY RECOVERY SYSTEM USED AT AUTOTRUCKS WHICH MOVES WHITOUT EFFECTIVE LOAD
CRĂCIUN OVIDIU MIHAI, ŢÂRULESCU RADU
In this paper we develop a system which is relative easy to made. This system is made of a container with wheels of small size (maximum load 400 kg), fixed with joints of the rods of some plunger pumps. When the auto-truck moves on the road, these pumps can deliver oil under pressure to a hydraulic accumulator fixed on the auto-truck’s platform. The stored energy can be used for different purposes like: tyre inflation; to screw in/out the wheel’s screws with hydraulic pistols; the actuation of a rotary hydraulic engine coupled with the transmission, which will supplement engine’s power when climbing a road, etc. The article presents constructional elements and calculations of such a recovery system.
IMPROVEMENT OF STEAM-CONDENSATE SYSTEM EFFICIENCYIN PAPER MACHINES
HAZI ANETA, HAZI GHEORGHE
In this paper there are presented steam-condensate system in existing paper machines and ways for improvement them. It is realized a case study for a paper machine during operation. There are shown energetic indicators for some working regimes and saves possible.
EXERGY FLOWS IN THE PAPER MACHINE
HAZI ANETA, HAZI GHEORGHE
Energy analysis is necessary to minimize specific energy consumption. In order to qualitatively describe the energy, the use of exergy is necessary. Thus, the energy analysis must be completed by the exergy analysis. The exergy analysis establishes the causes and the true values of the energy destructions and so, of the energy losses.This paper presents an algorithm for establishing of exergy flows and results obtained for a paper machine in a company.
NEW TECHNOLOGIES FOR HOSPITAL WASTES TREATMENT
ION V. ION, SPIRU PARASCHIV, PARASCHIV SIMONA LIZICA
Medical wastes due to the hazards to the human health and to the environment require special handling, treatment and disposal, usually according to specific regulations and guidelines. Because of financial difficulties, many hospitals have tried to find some cost-effective treatment and disposal means of their waste. In this paper are describes new methods for treatment of medical wastes.
ANALYSIS ON ENERGY AVAILABLE IN SOIL TO BE USED FOR HEATING DWELLING PLACES
NEACŞU S., TRIFAN C., ALBULESCU M., EPARU C., IONESCU E.E.
This paper proposes an analysis on the soil`s available thermal power that can be used for heating dwelling places. The calculation of this resource`s size, for various types of soil, using the numerical model introduced here, permits the simulation of the thermal energy available in soil production dynamics for specific values of time delay and depth.
THE EFFICIENT CHANGING METHODS FOR BRECHARGEABLE BATTERIES
OLTEAN IOAN
The use of rechargeable batteries as a prime power source is on the rise. Among the most widely used sources used to supply portable electric and electronic equipments are Nickel-Cadmium (NiCd), Nickel-Metal-Hydrid (NiMH) and Lithium-Ion (Li-Ion) batteries. By adequate charging batteries will feature better performance and longer life cycles. The paper presents the charging modes allowing for a long-term constancy of their functional parameters. The algorithms used in the adequate charging of the NiCd, NiMH and Li-Ion batteries are described of the typical charging processes and a new charging approach.
THE ELECTRICAL ENERGY CONSUMPTION IN LIGNITE OPEN PITS FROM ENERGETICALLY GROUNDS CE ROVINARI AND CE TURCENI
ORBAN MARIA DANIELA, PANA LEON, POPESCU CRISTINEL, ANCUTESCU IOSIF
The increasing of energetically efficiency and economic restructure program supposes an electrical energy consumption increasing using an average annual ratio about 1,1% in 2002/2005 and 2,5 % in 2005/2010 which represents the economic development strategy on the average and long time.
ENERGETICALLY AND EXERGETICALLY STUDY FOR TWO VARIANTS OF HEAT EXCHANGER ASSEMBLIES COMPOSED BY “n” UNITS
SERBANOIU NECULAE, MURESAN MARIA, UNGUREANU VIRGIL-BARBU
The work presents two variants of heat exchanger assemblies composed by “n” units where the primary heat carrier series circulates from the last unit to the first and the secondary heat carrier series or parallel circulates. There are analyzed the thermal efficiency, and the exergetic efficiency for both variants.
TESTING PLATFORM FOR ELECTRIC RELUCTANT MOTORS USING LabVIEW ENVIRONMENT
TRIFA VIOREL *, MĂRGINEAN CĂLIN *, ZĂRNESCU LIVIU **
The paper presents the development of a virtual laboratory accessed via Internet, by combining the existence of a real test-bench with the Internet facilities. The idea of remote control devices is quite new in electrical engineering. Present paper deals with a particular aspect related to a virtual laboratory, with the purpose of initiating in research of reluctant motors the researchers wishing to approach modern equipments at which they have no physical access. It allows not only distance learning for the beginners, but also the achieving of a stable electronic link between researchers and producers of reluctant motors. To benefit of such virtual laboratory one need knowledge in various fields such as: electro-mechanics, electrical machines and drives, digital control, instrumentation, Internet.
ENERGY INTENSITY OF THE ROMANIAN INDUSTRY IN THE CONTEXT OF EU INTEGRATION
TURBATU ADRIAN, VODA IRINA, RUGINA VASILE
Within OEN a data base of the main energy indicators at the national level, including primary energy, final energy and electricity intensity indicators, by economic sectors and industrial branches has been carried out and further developed.The paper presents the evolution of final energy and electric energy intensity of the manufacturing industry in Romania and of its representative branches. The analysis underlines the fact that the evolution differed from one branch to another. Thus, in the energy intensive industries, energy intensity has diminished. In the manufacturing industry, energy intensity has diminished due to a certain diminishing in the share of the activities in the energy intensive industries and a decrease in energy intensity in the food industry and other branches that have lower energy intensity.
THE SECOND LAW OPTIMAL OPERATION OF A VALMET NEWSPRINT PAPER DRYING MACHINE
ZVOLINSCHI ANITA
The entropy production for the paper drying process was derived for a newsprint paper drying machine located at Norske Skog ASA in Skogn, Norway. The entropy production of the total process was calculated for actual operating conditions (i.e. reference conditions) and then optimised subject to a defined outlet paper moisture content (i.e. 0.07 kg H2O per kg dry paper). Inlet air humidity and cylinder group conditions were varied. Optimum conditions were obtained for a range of inlet air humidities, and for different cylinder groupings. We found that it was very favourable to increase the inlet air humidity. The realisation of such a change is probably hampered by unwanted condensation. Other changes had a negligible effect on the entropy production.