Refrigeration engineering and technology

12-19

Authors: A. S. Titlov; G. V. Shlapak

New designs of universal cameras with absorption cooling units, which use modern technical and technological solutions (removal of the evaporator outside the refrigerating chamber, the heat trans-fer systems based on heat pipes, cold-accumulating materials, effective contact fillers based on the po-rous compressible material) are presented in the paper. The results of experimental studies of such cameras on the example of the low-temperature processing (frozen) of meat products simulators are shown. Examples of the utilization of low-temperature cameras in the farm conditions are given.

27-34

Authors: V. V. Milovanova

A review of the existing types of fuel cells, their advantages and disadvantages, as well as the prospects for their use in the automotive industry has been carried out in the paper. General problems that make it difficult to launch fuel cell vehicles in series production are analyzed, some suggestions for dealing with them are proposed. Examples of application of fuel cells in cars today and a forecast of development of these technologies in the future are given.

47-51

Authors: O. A. Titlova

Today humanity is beginning to understand the consequences of ill-considered use of energy resources. In the last decade a new direction of the economy is actively developing – «The Blue Economy». Its aim is to find innovative solutions that are safe for the environment and society. Bioenergy is one of the directions of the «Blue Economy» which is actively developing lately. The article discusses the possibility, advisability and examples of the algae use as a feedstock for the energy resources production: the concept of a new generation of house – «BIQ house», which is powered by energy from microalgae which is in its panels; production of oil and gas in specialized reactors. The different ways of growing the biomass required to biofuels production and the use of such technologies in Ukraine are considered.

59-66

Authors: N.N. Lukianov; А.V. Меlnyk; V.P.Zhelezny; О.Ya. Khliyeva; А.S. Moroz

The results of a comprehensive experimental and theoretical study of the effect of compressor oil and TiO2 nanoparticle additives in isobutane on the local flow boiling heat transfer coefficients in the tube have been presented in the paper. The preparation of the working fluid (R600a / mineral oil / TiO2 nanoparticles) for systems with hermetic compressor Atlant CKH 150 has been described. The experimental data were approximated by the model that take into consideration the effect of oil and nanoparticle additives in the refrigerant on the local flow boiling heat transfer coefficient in the tube for solutions R600a/oil and R600a/oil/nanoparticle TiO2. It was shown that the TiO2 nanoparticle additives at concentration 0.0026 - 0.006 % wt. in the working fluid R600a / mineral oil does not influence on the values of the local flow boiling heat transfer coefficient in the tube.

80-87

Authors: V. Mikhailenko; N. Kniazieva; M. Solodovnik

The analysis of the efficiency of domestic and foreign coal-fired thermal power plants, which use modern innovative technology, demonstrates the advantage of the latter by an average of 3-7%. In this connection there is a scientific challenge of steam generators thermal processes re-regulation system effectiveness improvement on the basis of intelligent systems of control the solid fuels com-bustion process. Intelligent automatic control system operates on the basis of the fuzzy logic theory and has the ability to adjust the fuel consumption because of possibility of taking into account its physical and chemical properties. Developed knowledge base of fuzzy controller and proposed structure of the intellectual automatic control systems of combustion process. ACS will allow im-proving fuel combustion processes and making savings in the base mode and adjusting mode.

92-98

Authors: V. V. Trandafilov; M. G. Khmelniuk

In present numerical research, the mathematical model for precise performance simulation and detailed behavior of Stirling refrigerating machine is considered. The mathematical model for alpha Stirling refrigerating machine with helium as the working fluid will be useful in optimiza-tion of these machines mechanical design. Complete non-linear mathematical model of the ma-chine, including thermodynamics of helium, and heat transfer from the walls, as well as heat transfer and gas resistance in the regenerator is developed. Non-dimensional groups are derived, and the mathematical model is numerically solved. Important design parameters are varied and their effect on Stirling refrigerating machine performance determined. The simulation results of Stirling refrigerating machine which include heat transfer and coefficient of performance are presented.

12-16

Authors: N.V. Zhikhareva

The paper describes the features of air conditioning systems design for indoor year-round operation pools. The features of humid heat load calculation and air consumption of air conditioning swimming pools air consumption are shown. According to studies, a comprehensive model for calculating of swimming pool air conditioning, including the determination of optimal parameters definition of insulation thickness economic feasibility has been carried out. Selection of air conditioning system was made.

21-29

Authors: А.S. Lukiyanova

Taking note of bulk viscosity is especially important at the description of high-intensity processes, such as explosion, a flow with high speeds, the acoustic phenomena, and also in characteristic points of a condition of substance. Bulk viscosity characterizes ability of substance to transformation of mechanical energy in thermal at nonequilibrium volume deformation. In the work the main theoretical directions of bulk viscosity influence studying are considered: physical acoustics, hydrodynamics, molecular and kinetic theory of gases and liquids. It is established that the molecular mechanism of the bulk viscosity emergence described in Landau's Enskog, Kramer works allows more deep understanding of the physical processes which are taking place at change of volume in the compressed liquid. Special interest is submitted to the theory of relaxation proposed by Mandelstam and Leontovich where the equation of a state includes the parameter defining internal structure of liquid that allows to consider effects of acoustic waves distribution. Expediency of Green-Kubo formula application which connects bulk viscosity with autocorrelation function of pressure microscopic fluctuations is noted. The existing methods of bulk viscosity coefficient experimental determination such as acoustic spectroscopy and Brillouin-Mandelstam scattering are analyzed. Problems of bulk viscosity near a critical point liquid-gas determination are considered.

37-44

Authors: V. P. Zaykov, V. I. Mescheryakov, Yu. I. Zhuravlev

A comparative analysis of the basic parameters and reliability indicators of the single-stage thermoelectric cooling devices while using different combinations of settings compared to traditional initial materials of a similar efficiency for changes in temperature from 0 to 60 K and operation modes from maximum cooling capacity to the minimum failure rate is presented. It is shown that the use of initial materials with higher conductivity compared to the traditional means to increase the cooling capacity or to reduce the number of elements, to increase the thermoelectric cooling power, to reduce the failure rate and thereby to increase the probability of thermoelectric cooling device failure-free operation. It was obtained the simple ratios of interrelation of parameters and indicators of reliability for a variety of combinations of initial materials depending on the thermoelectric cooling power and temperature differential. It is shown that under the condition of a constant heat load and temperature difference parametric constants of thermocouples amount on the thermoelectric cooling capacity production. Analysis of the traditional version failure rate and other combinations of failure rate had helped to identify that the failure rate production on the maximum thermoelectric power is a constant for any combinations of the parameters of the source material, for any operation mode and temperature difference. The possible application of the superposition principle when building a single-stage thermoelectric cooling devices of a high reliability by combining of a constructive method (mode selection of thermoelectric cooling devices) and parametric method (selected combinations of the initial material) were discussed. It’s shows the application of the principle of superposition of structural and parametric methods of construction of thermoelectric cooling devices could significantly increase the reliability of thermoelectric cooling devices.

53-59

Authors: V.Y. Labay, D.I. Harasym

Nowadays for Ukraine the problem with saving energy resources is especially relevant in a conditions of market economy, where the main energy carriers, such as oil and gas, are limited. That’s why in the last decade with the aim of saving energy resources the fundamental researches of activity of different branches, manufactures and technologies from positions of exergy methodology are held abroad. Today cost estimates can’t be the only measure of effectiveness of energy equipment which recycles energy resources. Exergy is physical, not economical criterion and determines independence of this parameter from price fluctuations. The application of exergy allows to give objective assessment of energy resources of any type as it is the only measure of working capacity, applicability of energy resources. There are many examples of successful application of exergy methodology by technical and economical optimization in industry, especially in energy intensive branches. The minimum should be determined by exergy losses per unit of provided heat, not by financial costs. The analysis of exergy effectiveness of implemented central straight flow air conditioning system (ACS) for operating cleanrooms which was obtained on its innovative mathematical research model depending on different factors that have influence on its work was presented in this article, and ways of energy saving for this ACS was proposed. It was found that the biggest impact on exergy output-input ratio of its air conditioning system have the temperature difference between inside and supplied air in a room, temperature of inside air which is depends on temperature of outside air, and coefficient of transformation EER of chosen refrigeration machine of air conditioning system. It was shown that with the aim of energy saving the implemented air conditioning system should be preferably used at a higher temperature difference between inside and supplied air, for example, = 9,0°С (at any temperature of inside air) and at higher coefficient of transformation, for example = 4,0, which gives the opportunity to get the highest exergy output-input ratio , which means to get the most energy saving variant of exploitation of implemented air conditioning system.

65-69

Authors: L.I. Morosuk, S.V. Gaiduk, B.G. Grudka

Development of small agricultural production outside the settlements is constrained by the technical difficulties of implementation and cost of centralized power and heat supply. Low power energetics is capable for combined production of electricity and heat in a cogeneration system. Further energy efficiency increase of a small power plant is provided by trigeneration, wherein one kind of primary energy is transformed simultaneously in the three beneficial effects: electricity, heat and cold, which are equally needed to agricultural production. In the particular example of the farm, which has quarters, greenhouse and cold storages, the needs of recovered heat during the year were calculated, set a reserve and recommendations for its redistribution between the two beneficial effects: heat and cold, in accordance with the technological process of agricultural production were made. It is shown that the trigeneration system is capable of providing high energy efficiency of small autonomous power plant in the agricultural sector.

75-81

Authors: K. V. Agyeyev , A. E. Denysova

The paper considers the basic theoretical concepts of vortex motion in relation to the solution of technical problems. The issue of instability of spiral vortex spatial structures when doublet or triplet of vortex filaments occurs is considered on the basis of the vortex theory. The problem of current importance is investigation of existence parameters for swirl or spiral shape disturbances. The disturbances so called processes with precessing vortex core (spiral shape vortex). The assessment of heat engineering equipment, in particular, recuperative heat exchangers is conducted. It is displayed that heating engineering units – vortex devices such as vortex combustor, combustion chambers etc. – have considerable advantages due to the operation in the active hydro–gasdynamic modes, and efficiency of their work is mainly depends on the operating and design parameters. The vortex effect that occurs in these devices allows making them compact, with an increased energy efficiency ratio, which corresponds to the objectives set in the Energy Strategy of Ukraine 2030. A construction of the jet-vortex compact recuperative heat exchanger, the operation features of which are in good agreement with the theory of the concentrated vortices, is given. It is displayed that the work of the jet-vortex recuperative heat exchanger is not completely identical to the cyclone vortex heat exchangers by the nature of the processes occurring there. The process of making decisions on the design parameters of a physical model (a cold aerodynamic experimental unit), its aerodynamic calculations and the selection of parameters for CFD-simulation of jet-vortex recuperative heat exchanger is considered. A technique for research on a physical model and its design is represented. The operation of the experimental unit is described. According to the results of CFD-research for recuperator operation, the high adequacy of the numerical CFD-model developed on the basis of the physical and simulation modeling results is presented.

92-96

Authors: J. Kozonova, N. Povarova

Functional foods market is changing rapidly. Now the market has the highest growth. In the European Union food producers try to fit virtually every product under the "functional" definition. In this article we will review major trends in the EU functional foods market and try to analyze them. It is well known that foods fortified with nutritional and disease-preventing qualities are invigorating the world food industry. Health-conscious consumers are driving the demand for products that aim to promote better health, increase longevity and prevent the onset of chronic diseases. With a fast-emerging middle class, more disposable income, and a greater number of working/more educated women in emerging markets, the worldwide potential for functional foods/beverages is unprecedented. Milk formula, energy drinks, probiotic yogurt, juice drinks, sports drinks, cereal, and biscuits were among the top-performing functional global health and wellness food categories in 2014. There is a breakout of the year's top trends driving the market for functional foods and beverages. A review of recent deal drivers, the fastest-growing products and innovation trends can help businesses identify the most promising entry points to this market.

102-107

Authors: N.A. Kniazieva, A.S. Kalchenko

The method of controlling the quality of services in next generation net-works using the theory of fuzzy sets is presented in the paper. The algorithm of the quality of services management system is given. The proposed method of service quality management can effectively monitor and maintain the degree of users satisfaction with the services at the required level.

10-13

Authors: А. V. Zimin

At refrigeration storage of fruit and vegetables it is necessary to support the optimal technological mode in stores. Deviations of the mode result in the considerable losses of mass and product quality. Basic influence on evenness of the temperature-humidity field is rendered by the systems of storage room air-distribution. The systems of air-distribution are a channel, channel-less and active aeration. The channel-less systems are based on separate unit coolers that is up-diffused on the area of chambers. Such systems are the simplest and cheapest. The channel systems have one or a few forcing and suction channels. Placing of channels provides the even temperature-humidity field in a chamber. Such systems are more difficult and expensive. Principle of work of the systems of active aeration is based on creation of the set technological mode directly in the stack of fruit and vegetables. The use of such technology allows taking the losses of product to the minimum.

22-25

Authors: M. Khmelniuk, N. Zhikhareva, O. Olshevska

The impact of expedient-economic insulation thickness on energy and resource saving fruit-vegetable warehouses cooling systems optimization is examined in the paper. The method of cal-culation is presented. The calculation results for expedient-economic thickness of modern insulating materials are introduced.

34-41

Authors: Amina Abdessemed

Conception of creation of the water evaporative chillers of new generation is worked out with the use of air-water heat-exchanger for the preliminary cooling of entering air, at its unchanging moisture content. The natural limit of cooling in such systems is a dew of outward air point, that substantially extends capabilities of the evaporative cooling technique practical use as a whole and allows to decide the tasks of refrigeration and air-conditioning systems with a substantial power cost cutout on realization of processes and simultaneous decline of level of harmful ecological influence on an environment. In the evaporated cooler multichannel structures are used from polymeric materials. Traditional type and new generation water chillers capabilities comparison is executed at varying of initial parameters and correlation of gas streams and liquid in the basic contours of the evaporative chillers.The special attention is spared to the issue of water vapor condensation on the satiation line in transition on the deep evaporative cooling of environments. The comparative analysis of such coolers capabilities is executed on the basis of theoretical and experimental data of the author, as it applies to the solution of evaporative cooling tasks.

53-61

Authors: O.Yu. Rozina, V.B.Rogankov

We propose the simple model of the heat flux generation throw the open end of the capillary cannel submersed into liquid, where an ultrasonic field is formed. This model is based on the previous experimental research of the sonic-capillary effect. The peculiarities of them are: the excitation of cavitations strongly under the capillary cannel; the translation motion of cavities to the capillary cannel, recorded by mean of the moving image camera with the velocity of about 160000 frames per second; the local heating of liquid in capillary and temperature distribution in the capillary cannel; the gradient of temperature directed according the translation motion of the cavities. The principal distinction of our model is that the cavitation process is connected with a periodical phase transitions. Due to the directional motion of cavities to the capillary cannel, all thermodynamic processes, connected with extension of cavities and which need some quality of heat are located under the capillary cannel; the decreasing of cavities and the return of heat are located in the capillary cannel. Thus, the result heat flux forms throw the open capillary section. The proposed model is realized as a software and calculated in wide ranges of temperature, diameters of cavities, frequencies of ultrasonic. The density of heat flux was calculated for the conditions of based experiments.

66-75

Authors: P.V. Borzenkov, V.P. Zhelezny

Issues of nanoparticles impact on the parameters of the phase liquid-liquid equilibria in the gen-eral vicinity of the critical point are considered in the paper. Binary system exfoliating nitroben-zene/n-heptane and nitrobenzene / nanogeptan are been objects of study. Simulation results of phase equilibrium liquid-liquid using the extended scaling equations are given. It is shown that for an adequate description only three coefficients and critical system parameters are necessary. The rule of rectilinear diameter for exfoliating systems is applied. Critical phenomena in the curves for the three-component separation nanofluids (nitrobenzene / heptane / nanoparticles TiO2) are isomorphic phenomena on the curves of the bundle of binary solutions (nitrobenzene / heptane).

84-89

Authors: A.A. Kondratenko, B.V. Kosoy

The use of grooves, as the structure of flat plate heat pipe is widespread and is a popular and effective technical solution in the practical implementation of various design systems for thermal control of electronic equipment. Advanced thermal control system must meet two criteria: 1) have a high heat transfer coefficient; 2) remove heat of high density. However, the last criterion leads to the fact that the high density heat flux may lead to a boiling limit, which leads to a drastic decrease in heat transfer coefficient, and conducts to a rapid increase of surface temperature. The paper presents an experimental investigation of the heat transfer characteristics of the microgrooved structures at vaporization of water and ethanol. The structures are represented in the form of axial grooves with a square section dimensions of 0.3, 0.5 and 0.7 mm, and a rectangular cross section with the same width and pitch parameters of the channel but with double depth of channels. Studies showed that in the grooved structures three modes of vaporization occur as follows: evaporation, evaporation-pulsation and boiling. The experiment revealed the area having constancy of the heat transfer coefficient at varying specific heat flux that is typical for evaporation. At certain heat flux value the nucleate boiling in the grooves is initiated, and heat transfer coefficient is growing at increasing heat flux. Boiling in the channels of micro-grooved surface is accompanied by a slug boiling regime, and formation of a thin liquid film on the surface of the channel. It is essentially increasing the heat transfer characteristics of the micro-grooved structures. Double of the channel depth leads to increase in heat transfer coefficient up to 30 - 40% for both water and ethanol. Increase of the heat transfer coefficient could be explained by the enlargement of the heat transfer surface of the channels. Increasing of the effective pore radius by the increasing of the channels depth leads to reduction in the hydraulic resistance of the channels that accompanies increase of the critical heat flux up to 50 - 60%.

98-103

Authors: A. A. Gnatovskaya

The article represents the issues of simulation of heat-loaded means with reservation of critical systems in CAD systems. The reliability parameters of heat-loaded devices cannot be achieved only by parametric methods and require to ensure efficient management of their reliability. Achievement of this level of reliability for heat-loaded systems is possible by hardware redundancy, i.e. redundant. The model which could improve the heat-loaded system reliability through the use of hardware redundancy, based on the use of redundancy techniques was presented. The effectiveness of reservation techniques in the early stages of development and design determines its usage for reliability improving as critical thermally loaded elements and the system as a whole. Application of the proposed model of reliability improvement of heat-loaded means due to hardware redundancy in the CAD subsystem allows evaluating the effectiveness of different methods of hardware reservation to improve the reliability of heat-loaded system.

113-120

Authors: I. Kolumba

The paper considers the existing principles of management services in intellectual add-in of NGN - centralized and decentralized management, shows their advantages and disadvantages. The architecture of intellectual add-in with a mixed control strategy was proposed which presents several hierarchy levels, which are key nodes of intellectual add-in. The lower level has a few Softswitch, which are connected to each other. At the top level of the hierarchy there is a universal server, which is a single control center. At an average level there are specialized server services, connected with the central control device and a Softswitch. Intellectual add-in with a mixed architecture offers several approaches to service requests. According to the first approach, the request for service arrives at one of the dedicated servers through the connected Softswitch installed in a separate area. In the other, the request is taken Softswitch, which is connected to the universal server services. The choice of management approach to intellectual add-in builds on the assessment of management effectiveness of intelligent services, the calculation of which is necessary to consider individual indicators of quality. As partial indicators of intellectual services provision quality the author proposed to use the total residence time of request for intelligent service in management system, the total waiting time of request service, the probability of request blocking on the server on the upper level of intellectual add-in, the probability of request service on the server on the middle level of intellectual add-in, the control system cost. The calculation of the final effectiveness based on the proposed specific indicators for each of the presented approaches to architecture of the intellectual add-in will provide an opportunity to determine the best management option.

10-12

Authors: A.V. Zimin

In the paper the technical features of binary ice screw type generators design are considered. The basic element of this type machines is a pair heat-exchanger-screw. The heat exchanger may be deformed. Screw in the process wears out. During work with the oscillation loading at a subzero temperature there are problems that result in the decline of efficiency or machines breakage. Recommendations on planning of machines of this type are given. In addition, work of screw generator is considered in a pair with the accumulator of cold. Using of accumulator reduces capital and operational costs. A properly designed heat balance of such a system will make it possible to minimize internal losses of cold. The complete chart of setting of this type is presented. The machine operation modes are analyzed.

18-24

Authors: V.Y. Labay, D.I. Harasym

Exergetic method is a universal way of thermodynamic research of various processes of energy transformation in energy technological systems, to which air conditioning system for cleanroom belongs. Implementation of exergetic analysis for energy technological system makes it possible to determine the influence of various elements of its system on its work and because of this to increase the effectiveness of work of energy technological system in general. Effectiveness of work of any air conditioning system depends on energy effectiveness of refrigeration machine, which serves it and consumes electricity for reducing the heat of supply air which enters the room. And it means that the main purpose of selection of certain refrigeration machine for air conditioning system is to reach the maximum cooling capacity with minimum energy consumption. Innovation mathematical research model of the central straight flow air conditioning system for cleanroom in order to computer estimation of its energy effectiveness by virtue of exergetic output-input ratio depending on different factors, which have influence on its work, in particular the coefficient of transformation EER of its refrigeration machine was used in this article. The dependences of exergetic output-input ratio of chosen air conditioning system for cleanroom on coefficient of transformation EER of its refrigeration machine by different parameters of outdoor and indoor air and the temperature difference between the indoor and supply air were presented. It is shown, that the chosen air conditioning system should be preferably used by higher coefficient of transformation EER of its refrigeration machine and higher difference between temperatures of indoor and supply air by various temperatures of outdoor air, that will give the opportunity to gain the highest exergetic output-input ratio , which means to gain the most advantageous economical variant of exploitation of chosen air conditioning system.

32-37

Authors: A.N. Radchenko, О.V. Ostapenko

The efficiency of waste heat transformation from gas engines in the plant forintegratedenergysupply by lithium bromideabsorption refrigerating machine was analyzed. Such gas engines are equipped with heat exchangers for producing hot water from the engine recoverable heat. The waste heat from gas engine jacket and lubricant oil cooling water, scavenge gas-air mixture and exhaust gas are used to produce hot water with the temperature of about 90 °С as heating source for absorption chiller. The analysis was made for trigeneration plant on the base of cogeneration reciprocating gas engine modules JMS 420 GE Jenbacher (electrical power output of each cogeneration gas engine 1400 kW, thermalpower output 1500 kW). This trigeneration plant was designed for combined energy supply of the factory "Sandora"–"PepsiCо Ukraine" (Nikolaev, Ukraine). The trigeneration plant, equipped with two cogeneration JMS 420 GE Jenbachergas engine modules and a single-stage absorption chiller, has been designed and assembled by "Sinapse"–"GE Energy" (Kiev) and "Khladotechnika" (Nikolaev). The absorption chiller produces chilled water for technology process cooling and conditioning of engine room intake air. The significantheat losses were revealed caused by the cogeneration gas engine modules and the lithium bromideabsorption chiller temperature regime performance discrepancy. In its turn it was caused by the increased temperature of return water from the single-stage absorption chiller of about 75 °С to the parts of the gas engine to be cooled. But in respect of the condition of engine reliable maintenance at the appropriate thermal rate the temperature of the return cooled water entering the engine cogeneration system is limited to the design value not exceeding 70 °С. If it excess, a surplus heath of return water is rejected to the atmosphere by the cooling tower. Return of excess heat to a single-stage absorption chiller is impossible because of its temperature of 75…78 °С lowered rather design temperature of the supply hot water for a single-stage absorption chiller of 90…95 °С. Fall of temperature of the supply hot water to a single-stage absorption refrigerating machine would cause considerable dropping the efficiency of transforming a gas engine recoverable heat into a cold – decrease in coefficient of performance (COP) from nominal (design) value of about 0.7 to 0.5 and lower. The results of water temperature and flow measuring showed the heat losses of 30...40 % of the heat transformed by absorption chiller into a cold.There were proposed an improved two-stream system of return water flow to the cogeneration gas engine modules that reduces the heat losses compared with traditional one-stream variant. In the two-stream system the watermass flow through cogeneration gas engine modules and absorption chiller is increased up to about 150 % compared with the base variant and the return cooled waterflow from the absorption chiller is divided into two streams.With this the temperature of the supply hot water for the absorption chiller, leaving the cogeneration gas engine modules, and the temperature of return cooled water from the absorption chiller is lowered as compared with the base one-stream system. Oneofthereturn water stream – ofthesamemassflowasinthebasevariant but at the lowered temperature–iscooled down to the required temperature of 70 °С as in thebasevariantand directed to the gas engine nodes those need cooling. The other (addition) return water stream of the50 % massflowand of increased temperature higher than 70 °С is delivered directly to the gas engine exhaust gas recovering boiler (economizer) by-passing the gas engine cooling nodes. It was shown that the two-stream system of return water flow to the cogeneration gas engine modules increases cooling capacity by approximately 25 % compared with traditional one-stream variant due to reducing the heat losses during transformation of gas engine waste heat into a cold.

42-47

Authors: A.S. Boychuk

Equations for alternative refrigerant R134a viscosity and thermal conductivity calculation expressed in terms of independent variables, such as temperature and density are worked out. Equation coefficients are determined by the least square technique according to the experimental data. The equations describe viscosity at temperature ranging from 248 to 439 K at a pressure up to 6,0 MPa and thermal conductivity at temperature ranging from 248 to 533 K at a pressure up to 60,9 MPa. The composed equations accuracy is quite acceptable for the engineering calculations.

53-58

Authors: P.F. Stoianov

Heat pump installation are very efficient heating and cooling systems and can significantly reduce your energy costs. The technical and economic performance of a heat pump is closely related to the characteristics of the heat source. This paper presents an overview of different heat sources for heat pumps, recommendation for designing this systems. The heat source temperature and its constancy during a year depend very strongly on the type of heat source. The heat pump performance were analyzed using ground and air temperatures for Odessa. The results of research indicate of natural temperature distribution in ground. Areas of natural temperature distribution in ground demonstrate short and long-term fluctuations of temperatures. Short-term fluctuations are influenced by weather and they exist only up to 1 m below ground surface. Long-term fluctuations (known also as seasonal fluctuations) occur in the second area (up to 8 or 20 m depending on the ground type). In deep area for every particular ground type temperature stays constant and very slowly increases with depth according to geothermal gradient, which indicates thermal impact of Earth's inner core.

65-71

Authors: S.S. Surkov, A.N. Martynyuk

Along with the crucial growth of information-technologies the communicability of the society is rapidly developing. Multiple social networks is the brightest example of this fact. All automobiles manufacturers strive to provide embedded computers with access to the Internet, but some embedded computers does not have a built-in browser. To solve the problem of applications authorization protocol OAuth was created, the aim of which is to enter Web-browser accounting data. This paper describes the implementation of the OAuth realization solution for embedded computers that do not have browser support. All social networks such as Facebook, Twitter, Google+, Foursquare, Evernote, VK provide WEB REST API which allows to create native application easily for any platform which have internet access. The communication is going through Bluetooth. As access to internet is implemented via Bluetooth protocol there won’t be technical difficulties to use the app. This method could be implemented as for iOS (headunit is needed to be MFI certified) or for Android. This paper describes the solution of implementing OAuth for headunits which without browser support.

17 - 20

Authors: A.N. Gorin; A.B. Kudrin; M.V. Domin; O.N. Burdiyan

Experimental researches of temperature distribution on the evaporator surface of the household DH-239 refrigerating appliance working at isobutane depending on a charge dose of refrigerating system are conducted. The received results can be used for microleaks diagnosing methods development during household refrigerating appliances operation.

25 - 30

Authors: А.Е. Lagytin; P.F. Stoianov

Finned heat exchangers are the basic type of heat exchanger employed in many industrial applications such as refrigeration, air conditioning and other thermal processes. This paper presents experimental research of air-side heat transfer of finned surfaces. Seven types of finned surfaces are employed in this study. Investigation describes temperature fields and temperature cooling air-flow changing in the inter-fin duct without taking into account tube section. Temperature difference in-between local real air temperature data and fin surfaces are determined. The air-side heat transfer coefficients of finned tubes were evaluated at various air flow rate. Experimental setup was designed to simulate a single passage in a fin-tube heat exchanger. The heat transfer improvement of finned surfaces is a problem which includes several factors. Among the main factors are the fin form and its material. A series of tests presented in this paper reveal visual and quantitative details of local fin-surface temperature distributions for steel and aluminum fins. The air-side thermal performance data of finned surfaces were analyzed using conditional coefficient of heat transfer. Tube displacement in regard to fin on its thermal characteristics is evaluated. Experimental results have also shown that edge type of the inter-fin duct is not influenced on heat exchange performance. The results of research indicate that conditional coefficient of heat transfer can be used for performance comparison of finned heat exchange surfaces. This method is very useful for simple heat transfer estimation of finned surfaces for a wide range of practical applications.

35 - 46

Authors: A.V. Doroshenko; V.A. Goncharenko

Scheme solutions of heat-cold supply and air conditioning combined solar systems, based on the open absorption cycle with an absorbent indirect regeneration and new types of heat-mass exchange apparatus with “gas- liquid- solid body" movable nozzle utilization were developed. For the first time evaporative air and water coolers of indirect type with regular structure nozzle and mobile-three-phase layer placed between the nozzle heat transfer elements, which increases the homogeneity of the moving layer processes and growth of the of heat-mass-transfer processes efficiency were developed. On the basis of theoretical and experimental research practical recommendations for determining solar systems optimal mode parameters and geometric parameters of the main elements of heat-mass-transfer equipment have been worked out.

55 - 60

Authors: О. Pylypenko; А. Forsiuk; Ya. Zasiadko; V. Glushkov

The use of correlations that would be capable to adequately account for the heat transfer between the surface and refrigerant are crucial for the accurate design calculations and proper heat transfer equipment sizing, including cold accumulators with ice generation on the heat transfer surface. A vast multitude of such correlations for the determination of overall heat transfer coefficient valid for different cross sections pipes and processes conditions are available now in the literature. The calculations of heat transfer pertinent to the conditions of cold accumulators, lead to the results drastically deviating from those obtained in the framework of the direct experimentation carried out at the Department of Power Engineering and Industrial Refrigeration of NUFT. In order to mark one or some of such correlations, that might have been used within the engineering calculations under condition of their proper correction, the critical comparative analysis of the literature sources has been carried out. The mathematical modeling of the heat transfer process in the condition of boiling refrigerant, with taking into account the valid limitations towards correlations, has been performed. The graphical comparison of the modeling results calculation with chosen correlations is performed. The results of the analysis allowed choosing the correlations, which could be recommended to be used within the engineering design calculations of cold accumulators with the ice accumulation on the heat transfer surface. The applications of such design correlations that adequately reflect the mechanism of heat transfer between the surface and refrigerant would be critical for the accurate design calculations of the transfer equipment of the refrigeration units, including cold accumulators with ice generation.

69 - 75

Authors: L.N. Yakub

The results of the calculation of the thermodynamic properties: density, enthalpy, entropy, volume expansion coefficient and heat capacity of the solid polymeric nanocrystal - C60 at low temperatures in a wide range of pressures using theoretical equation of state are presented.