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- ДокументPOLYMERIC MATERIALS FOR SOLAR ENERGY UTILIZATION: A COMPARATIVE EXPERIMENTAL STUDY AND ENVIRONMENTAL ASPECTS(2016) Alexander Doroshenko, Kostyantyn Shestopalov, Ivan Mladionov, Vladimir Goncharenko, Paul KoltunFull-scale metal solar collectors and solar collectors fabricated from polymeric materials are studied in present research. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. Polymeric collector is 67.8% lighter than metal solar collector. It was experimentally shown that the efficiency of a polymeric collector is 7–14% lower than a traditional collector. An ecologically based Life Cycle Assessment showed the advantages of the application of polymeric materials in the construction of solar collectors.
- ДокументVISCOSITY OF TERNARY SOLUTIONS COMPOSED OF PROPYLENE GLYCOL, ETHANOL AND WATER(2016) O. Ya. Khliyeva, A. S. Nikulina, M. P. Polyuganich, S. S. Ryabikin, V. P. ZheleznyThis paper presents the experimental data on the kinematic viscosity of water / ethanol / propylene glycol solutions that are prospective as coolants. An experimental setup with capillary viscometers was used to measure the kinematic viscosity of samples in the temperature range from 243K to 303K and in the wide range of mass fractions of components. Experimental uncertainty of the obtained experimental data does not exceed 0.4 %. Solutions compositions were chosen according to needs of the refrigeration industry in order to provide a possibility of their application at temperatures 233 K and higher. The new model for prediction of the kinematic viscosity of coolants within wide interval of reduced temperatures 0.1 ≤ ≤ 0.6 ( is the pseudocritical temperature) based on the limited experimental data both for pure substances and aqueous solutions of mono- and polyalcohols is presented in paper.
- ДокументCOMPLEX QUALITY CRITERION OF CONTROL OF THE INTELLECTUAL SERVICES PROVISION IN NGN(2016) N. O. Kniazieva, S. V. ShestopalovThe paper is dedicated to intellectual services provision control quality comparison by the intellectual superstructures with centralized and decentralized control principles in NGN. The necessity of three parties interests consideration, namely: service providers, network equipment suppliers and network users is pointed out. The method of complex quality criterion formation is proposed.
- ДокументCOMPUTER PROGRAM FOR CALCULATION MICROCHANNEL HEAT EXCHANGERS FOR AIR CONDITIONING SYSTEMS(2016) Olga V. OlshevskaCreating a computer program to calculate microchannel air condensers to reduce design time and carrying out variant calculations. Software packages for thermophysical properties of the working substance and the coolant, the correlation equation for calculating heat transfer, aerodynamics and hydrodynamics, the thermodynamic equations for the irreversible losses and their minimization in the heat exchanger were used in the process of creating. Borland Delphi 7 is used for creating software package.
- ДокументMATHEMATICAL MODEL FOR THE STUDY AND DESIGN OF A ROTARY-VANE GAS REFRIGERATION MACHINE(2016) V. V. Trandafilov, M. G. Khmelniuk, O. Y. YakovlevaThis paper presents a mathematical model of calculating the main parameters the operating cycle, rotary-vane gas refrigerating machine that affect installation, machine control and working processes occurring in it at the specified criteria. A procedure and a graphical method for the rotary-vane gas refrigerating machine (RVGRM) are proposed. A parametric study of the main geometric variables and temperature variables on the thermal behavior of the system is analyzed. The model considers polytrope index for the compression and expansion in the chamber. Graphs of the pressure and temperature in the chamber of the angle of rotation of the output shaft are received. The possibility of inclusion in the cycle regenerative heat exchanger is appreciated. The change of the coefficient of performance machine after turning the cycle regenerative heat exchanger is analyzed. It is shown that the installation of a regenerator RVGRM cycle results in increased COP more than 30%. The simulation results show that the proposed model can be used to design and optimize gas refrigerator Stirling.
- ДокументA STUDY INTO ICE BUILD-UP AND MELTING ON VERTICAL COOLED PIPES(2016) Y. Zasiadko, O. Pylypenko, A. Forsiuk, R. GryshchenkoThe use of cold accumulators based on the principle of ice build up on the cooled surfaces during off-peak periods and ice melting during on-peak periods is an effective method of electricity bills reduction. Within comparatively short periods of on-peak demand a noticeable amount of thermal energy related to ice melting is to be released, it becomes clear that not only sizing of ice accumulators based on balance calculations is actual, but also the determination of time periods of ice accumulation becomes critical. This work presents experimental unit for obtaining data on the ice build-up on the vertical cooled pipes and later on to continuously register data on the ice thickness diminishing at the regimes of ice melting when cooling of pipe stops. The data for ice build-up and melting for some regimes have been presented and analyzed. The data form the base for deriving semi-empirical correlations allowing to determine a time intervals necessary to generate of ice layers of a given thickness.
- ДокументSOLUBILITY AND MISCIBILITY OF REFRIGERANTS R407C AND R410A WITH SYNTHETIC COMPRESSOR OILS(2016) V. Z. Geller, N. I. LapardinIn this paper, solubility and low temperature miscibility of refrigerants R407C and R410A in four different commercial Polyolester (POE) lubricants, produced by the same company but with different ISO standard viscosity grade, are measured with the aim to evaluate the possible correlation of solubility and miscibility with standard viscosity of the lubricant. Vapor pressure (solubility) is measured using calibrated, constant volume cells at oil mass fractions 30, 50, 70, 80, and 90% over a temperature range from -20 to 100 °C, and pressures up to 5 MPa. The measurements of low temperature miscibility limit (lower critical solution temperature LCST) were made using high-pressure sapphire cell. LCST was directly obtained by visual observation of a «milky haze» followed by a phase separation. Miscibility data were obtained at oil mass fractions from 5 to 50% over a temperature range from -60 to 0 °C. A set of simple equations was derived to describe the experimental results. Analysis of the obtained results showed that the solubility of refrigerant/lubricant mixtures depends weakly on the viscosity grade of the oil. At the same time, the miscibility gap (LCST) differ much bigger for various refrigerant/lubricant mixtures. The lower viscosity grade of the oil, the lower LCST of the refrigerant/lubricant mixture. LCSTs for the mixtures of R407C with the lubricants with the viscosity grades 32 and 220 differ by 30-45 °С.
- ДокументANTICIPATED COSTEFFECTIVE EFFECT FROM APPLICATION OF THE EJECTOR HEAT EXCHANGER FOR CONDENSATION OF LIGHT FRACTION HYDROCARBON ON THE PETROLEUM STORAGE DEPOT(2016) I. Butovskyi, V. Kogut, N. Zhikhareva, M. KhmelniukLoss control of oil products is the one of the relevant paths of saving of the fuel and energy resources play a crucial role in development of economics. Now a great many of different procedures of a choice of means of reduction of oil losses and petrol from evaporation are known. However the one part from them did not allow for value of these means and expenditures for them maintenance, another – did not allow for diversity of implementation of means of reduction of losses, third – uses outdated, now, the criterion. In the conditions of petroleum storage depots, as a rule, usage of ejector systems of trapping of light fraction are more preferential, than other hardware’s of reduction of losses. The positive effect from application of an ejector heat exchanger for preventing of losses of petroleum products are calculate.