Issue 4 (144)
Section 1. Refrigeration engineering
V.P. Zhelezny, А.V. Melnik
THE EXPERIMENTAL UNIT FOR INVESTIGATION OF HEAT EXCHANGE PROCESS FOR THE REFRIGERANT/OIL SOLUTION BOILING PROCESS IN TUBE
Description the experimental unit for investigation of boiling process for the refrigerant/oil solution in tube is presented in the paper. The information about heat transfer coefficient averaged over cross section of the tube, local heat transfer coefficient and oil concentrations in R-600a at the various void fraction of the working fluid in evaporator have been obtained. The experimental data obtained have been analyzed.
Keywords: Heat transfer coefficient ;Real work fluid; Boiling; Isobutan; Refrigerant/oil solution; Vapor quality; Concentration.
A.G. Nikulin, Yu.V. Semenyuk, N.N. Lukianov
THE EXPERIMENTAL UNIT FOR INVESTIGATION OF PURE LIQUIDS AND SOLUTIONS POOLBOILING PROCESS
This paper presents the experimental setup for investigating of the pool boiling characteristics for the pure liquids, refrigerant/oil solutions and nanofluids. The experimental methodology, the results of test experiments for the pool boiling of the isopropanol and refrigerant R11 are reported. A comparison between experimental data obtained and data calculated by existing models has been performed.
Keywords: Pool boiling; Heat transfer coefficient; Departure diameter of bubble.
I.V. Sekachev, V.А. Mazur
SIMULATION OF LEAKS IN THE VACUUM SYSTEMS
Fractal model of microfractures in the walls of cooled vacuum vessels for experimental thermonuclear reactor was considered. Pressure losses for fluid flow through microchannel network were estimated. Physical mechanism of cooling fluid penetration via hypothetic slits and cracks generating tree-structured microchannel network is described by the linear non-equilibrium thermodynamic relationships at the given pressure drop on the vessel walls. Computer fluid dynamics approach for homogeneous equilibrium model was applied to calculate the isothermal fluid flow.
Keywords: Microfractures; Vacuum systems; Fractal models; Gas leakage; Tree-structured microchannels
V.V.Minenkov, A.V. Zimin, M.G.Khmelniuk
INFLUENCE OF IMPURITIES ON ICE SLURRY PRODUCING AND APPLYING PROCESSES
This article discusses various aspects of the influence of impurities contained in the suspension of ice slurry on the processes of its production and use. The paper describes the main and associated processes of formation and accumulation of a binary mixture. The classification of the impurities that are used in the processes of making and using ice slurry. Various depressants and examples of their effect on the properties of ice slurry are considered. It is shown the modern ways of improving the application of a binary mixture with special additives that prevent the growth of ice crystals on ice and on the heat transfer surface.
Keywords: Ice slurry; Impurity; Depressant; Additive; Coolant; Agglomeration.
E.A. Smotrov, D.V. Vershinin, D.Y. Sheyko
LIQUID COOLING SYSTEM DEVELOPMENT WITH EFFECTIVE ENERGY USE FOR THE VEHICLE TRACTION ELECTRIC DRIVE
The drive liquid cooling issue research results are given. An assessment of the cooling cost effectiveness was executed. The cooling circuits and modes of operation were substantiated, temperature control unit was described.
Keywords: Cooling system; Electric transport.
Section 2. Power engineering and energy saving
THE LOSSES COMPENSATION BY CONSTANT ENERGY SUPPLY IN THEMULTILAYER FENCE
The regulatory framework for the calculation and control of heat losses streams crossing the multilayer cladding structures, rather limited by the rules governing the constancy of their thermal constresistivity during operation. As the alternative is given the perspective of control operating costs due to compensation from external sources. It is nеcessary to refine the existing norm (DBN V.2.6 -31:2006), and supplement it with regulations that permit application control methods of losses regulation on the stage of operation.
Keywords: Compensation; Standard; Regulation; Reserve; Operating costs; Specific thermal resistance.
DAILY AND SEASONAL TEMPERATURE DIFFERENCE FOR ELECTRICITY PRODUCTION
A new approach is proposed to the use of daily and seasonal air temperature minor difference as well as solar energy for the year-round electricity generation. underground heat and cold accumulators that allow to extend the temperature range for thermal power cycle and self-circulation coolants for heat-supply in the evaporator-condenser heat powered installation are used. The new technology is applicable to power plants with 100 ÷ 1000 kW capacity and is especially suitable for the production of electricity in the rural areas, which are distant from the centralized networks of electricity and gas supply.
Key words: Electricity; Production; Small temperature difference; Accumulation of heat and cold.
S.K. Sosnowsky, V.P. Kravchenko
WAYS OF EFFICIENCY INCREASE FORCOOLING TOWERS OPERATION
The parameters of cooling tower exploitation are specified. The walkthrough of existent indexes of functioning efficiency is resulted and the concept of thermodynamics efficiency of cooling towers is entered. An instrument over is brought to the operating personnel for simple determination of work efficiency and feasibility study of lead through the cooling tower reconstruction. The practical possibility of droplet carryover entirely removing is proven.
Keywords: Сooling tower; Сooling efficiency; Ground of reconstruction; Taking away of drops.
Section 3. Refrigerating and accompanying technologies
CONSTRUCTION OF ENERGY FUNCTIONAL BEVERAGES OF NEW GENERATION
One of the modern food industry development streams is the functional products’ production. Scientific justification of their design is given in the study. The increase assortment opportunity of functional juicy beverages is represented. It is offered to add an energetic compound to the juices. For this purpose the grain-growing and bean flour is used.
Keywords:Functional products; Energy beverages; Starch fermentation.
V. P. Kochetov, О. М. Tomchyk
NEW TYPES PACKAGING WITH HIGH THERMAL INERTIA FOR PLANT PRODUCTS STORAGE APPLICATION RESULTS
The results of experimental studies of apple’ storage in packages with high thermal inertia are represented. The influence of fluctuations of air temperature in the camera at the temperature of the fruit using packaging with liquid interlayers (with different thickness of the interlayers), and packaging without liquid interlayers are considered. The results of the quality assessment and determination of the mass loss of fruit during the period of storage are published.
Keywords: Storage of fruits; Fluctuation temperature; Packing with high thermal inertia; Liquid interlayers; The fruit quality; The mass loss of fruit.
AGROENERGOKOMPLEKS FUTURE – FOR GROWING AND PROCESSING ENVIRONMENTALLY PURE FRUIT AND VEGETABLE RAW
The AGROENERGYCOMPLEX (AEC), in which new technology of year-round cultivation and processing of ecologically pure fruit and vegetable raw materials (FVM), is proposed. AEC when implemented in stand-alone greenhouses producing clean (kosher) products – in the changed ground, without the use of mineral fertilizers and synthetic salt mixes hydroponic technology, without watering plants with polluted water, GMO free. AEC grows year – round irrigation of net melt water, lightened be deuterium and sets mode heat - humidity, harvest meets at least 3 times a year.
FOS is sorted and the part that has the subsistence for trade counter "not-selling" look "is directly and immediately near the site of" lossless aromatics and palatability - dehydrated by freezing. From juices the 40 ÷ 60% liquid concentrates, dry soluble powders and melt water for beverage production are produced, from the husks of FOS-dry insoluble powders. AEC do not consume "from outside" to grow and for processing of FVM or gas, no electricity, no water, no fuel for cars. Uses only internal resources – rain water, as well as the local water, which cleans itself by freeze-out, daily and seasonal temperature difference between the air and the sun's energy. AEC provides for heating and thermal stabilization of greenhouses, work their own power plants and complex on processing FVM heat accumulators phase transition on the roofs of greenhouses and underground heat and cold accumulators. Application of new technology of AEC was reviewed at greenhouses squares 10 and 20 ha with harvest of 2548 and 5860 t FVM /year respectively. AEC are especially suitable for areas distant from the centralized electricity and gas supply and is preferred in areas with extremely continental climate.
Keywords: Greenhouses; Eco-friendly products; Heat stabilization; Accumulation of heat and cold.
MOLECULAR DYNAMICS OF DISPERSE SYSTEMS. 3. DISPERSION ISOTROPIC COMPLICATED MOLECULAR ENVIRONMENTS
The molecular dynamics method (MMD) implementation in the context of the complicated molecular isotropic dispersive environments is considered. Particular attention is paid to elongated molecules systems, as well as systems of flat (discotic) molecules due to their wide practical application (hydrocarbon, refrigerants¸ coolants, etc.), and also due to the ability of the systems under certain conditions (temperature, density, external fields) to form liquid crystals, anisotropic environments. P-azoxyanisole (PAA), N-(p-methoxybenzylidene)-p-n-butylaniline (MBBA), Benzene-hexa-n-alkanoates (BHA) and other systems with a similar molecular structure are discussed in detail. Such systems are of particular interest considering their specific properties and possible new effects associated with a transition from isotropic liquid to liquid crystal and solid, in particular colloidal solutions and nanofluids.
Keywords: Dispersion systems; Molecular interactions; Molecular models; Elongated and flat (discotic) molecules; Structure, physical and chemical properties; P-azoxyanisole (PAA); N-(p-methoxybenzylidene)-p-n-butylaniline (MBBA); Benzene-hexa-n-alkanoates (BHA)
Section 4. Automatic, computer and telecommunication technologies
G.N. Vostrov, A. Atie, K.A. Levenets
Construction of mathematical models for real random phenomena based on random processes
Article contains description of random process in context of applying to models of real world processes. Especial attention is spared on condition`s complex and its connection to regularity. The key limitations in formal definition of random process usage for real data analysis problem are highlighted.
Keywords: Random process; Set of elementary events; Condition`s complex.
М. S. Solodovnik, А. М. Aslanov
USE OF NEURO-FUZZY APPROACH IN PREDICTING OF SERVER MEMORY MODULEMALFUNCTION
The paper presents the analysis of computer system malfunction mathematical forecasting methods. Based on the comparative analysis of correlation methods, mathematical statistics and neuro-fuzzy inference, the benefits of intellectual approach were proven.
Keywords: Computer network; Forecast; Reliability; Correlation analysis; Neuro-fuzzy system.
V.А. Кrisilov, Saleh Alaswad
THREE-LEVEL MODEL OF INFORMATION LEARNING PROCESS
The three-level model of the educational process, which is differentiated by the constituents such as subject area, granulation educational information, the schedule of the learning process is considered. Also the four-level model, intended for adaptation of the learning material to student educational process dynamics is examined.
Keywords: Adaptation of curriculum; Model of the educational process; Granulation of information; Dynamics of the learning process
IMPACT OF AUTOPILOTDEADBAND WIDTH ON ITS STATIC ERROR
The results of the research of the effect of the dead zone PID autopilot width on its static error are given. It was estimated that the presence of the dead zone static stabilization error rate is equal to the positive or negative value of the half-width of this zone.
Keywords: Stabilization of the course; Insensitivity of autopilot.