Refrigeration engineering and technology

4 - 11

Authors: G.M. Chen; A.V. Doroshenko; K.O. Shestopalov; O.Y. Khliyeva; A. Abdessemed

The concept of evaporative coolers of gases and fluids on the basis of monoblock multichannel polymeric structures is presented. Different schemes of indirect evaporative coolers, in which the natural cooling limit is the dew point of the ambient air, are discussed. In such systems the cooling temperature is lower than the wet bulb temperature of the ambient air. Special attention is paid to the recondensation of water vapor for deep evaporative cooling. It is shown that for the solution of the recondensation problem it is necessary to vary the ratio of the contacting air and water flows, particularly in each stage of the multistage system. Recommendations for the deep cooling process implementation in the evaporative coolers of gases and liquids are given.

17 - 22

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

In modern technologies, which are related to energy transformation, namely in the air conditioning systems, important place are occupied by objects creation and improvement of which requires the use of innovation thermodynamics. Classic apparatus of this science is often insufficient to solve new tasks; it is necessary not only to its further development, but its combination with the elements of a systematic approach and energetic. Innovation mathematical research model of the central straight flow air conditioning system for cleanroom in order to computer’s estimation its energy effective by virtue of exergetic output-input ratio and losses of exergy depending on different factors, which have influence on its work, was used in this article. The diagram of Grassmann of exergy flows and losses for chosen air conditioning system at outdoor air temperature 42°С was defined thanks to this model. It is shown that the chosen air conditioning system has high losses of exergy in the refrigeration machine, in the pump of cold water and in the fan unit, decreasing which will give the opportunity to gain the highest exergetic output-input ratio , and it means to gain the most advantageous economical variant of exploitation of chosen air conditioning system.

30 - 36

Authors: А.N. Radchenko

A method of analysis heat engine (gas turbine and internal combustion engines) cyclic has been proposed. The method is based upon thermohour potential of engine intake cyclic air cooling that depends on climate conditions of performance and a type of cooling machine. The feature of the method of thermoeconomical analysis with the use of thermohour potential of cooling, that takes into account a temperature and time factors, is the possibility to determine a rational type and power installed of cooling machine, that provides achieving the maximal effect in concrete climate conditions of engine performance.

43 - 50

Authors: M.O. Cheplyukha; Bondarenko; D.S. Minchev; A.V. Nagirnyi

The paper is devoted to the important scientific and technical problem of development of the modern and high-efficient storage and regasification liquefied natural gas terminal. The design, calculated performance and mass-dimensional parameters of heat exchangers and pumping equipment for the regasification system of the LNG terminal with annual capacity of 5 billion m3 at the northern Black Sea coast conditions are presented. The regasification system provides evaporation and superheating of liquefied natural gas to meet the given parameters of evaporated gas at the inlet of the main pipeline. The composition of the system includes heat exchangers: reboilers to evaporate the liquefied gas and superheaters to get the necessary temperature of evaporated gas. The seawater is suggested as the source of heat for evaporation and superheating of the natural gas, with the pumping station is to be used for pumping the water through heat exchangers. To make a sufficient investigation the change in seawater temperature throughout the season is had to be taken into account. Peculiarities of the annual maintenance of reboilers, superheaters and pumps due to change in the seawater temperature have been shown in the paper. A shell-and-tube heat exchanger type with multiple reverse flow of LNG is suggested to use for the reboiler. The superheater is designed as the finned-tube heat exchanger with multiple cross-flow of seawater. The set of limits was applied to the calculations among them are: the temperature drop of seawater on the heat exchanger is less then 3 °C (±1) and the maximum permissible speed of seawater in heat exchanger is 2 m/s. According to the calculations, the necessary amount of reboilers and superheaters is 10 items each type with the dimensions of reboiler about 1,25×1,4×4,1 m and superheater about 3,6×1,55×1,55 m. Seawater flow adjustment during the year, corresponding to its temperature, permits to meat ecological limits and to provide the regasification of the daily capacity of liquefied natural gas at the pressure of 4 MPa and outlet temperature greater than 2 ºC as it is shown by dint of mathematical simulation. The range of seawater flow is 6700…9350 kg/s, the necessary pumping station power – 4300 kWt

55 - 60

Authors: N.A. Prusenkov

Changing attitudes to the regulatory framework of mobility layers walling requires a revision of the calculation scheme for determining losses flow, passing it . This scheme favors the development of ways to avoid them arising from the temperature difference between adjacent layers on surfaces that are automatically excluded in enclosures consisting only of closed layers. It illustrated the temperature at the boundary alignment layers in the heat input moving component, the moving stream. Description of the method should be supplemented assessment of energy in the limit Lakh moving bed that goes beyond the purpose of publication

69 - 72

Authors: V.G. Marchenko; A.I. Lipa; A.P. Ponomarenko

In the paper the experimental results of air ions distribution from corona charge ionizers of different designs and capacities in the office space are given. The study has been carried out using such ionizers as: - effluence bipolar ionizer IWS-12D1-AE (Israel) with the productivity of 5·109 ion/sec working in «dark corona»; - effluence unipolar ionizer «Super Plus-Eco» (Russia) with the productivity of 5·1010 ion/sec working in «glowing corona»; - ionizer «Breeze» equipped with fan and designed using the device IWS-12D1-AE working in «dark corona». The small air ions counter MAC-01 (Russia) was used for determination of ions concentration. The results are presented as schemes demonstrating the air ions distribution at various height and distance from the ionizer to the breathing space of the person. The high local area concentration of negative air ions under the ionizer is detected. It is established that trajectories of air ions distribution from tested ionizers is characterized by a parabolical shape. The concrete recommendations for the arrangement of these devices are determined.

77 - 82

Authors: М. S. Solodovnik; А. М. Aslanov

Article, the authors considered, analyzes a very relevant topic. Indeed, fuzzy systems are being introduced today in virtually all spheres of human activity. With DSS, computer systems engineer designer can determine the quantitative characteristics of the network parameters (for example, the delay time). The authors have created a knowledge base. With this knowledge base, and Matlab (FuzzyTech) programming environment, the authors calculated the time delay of the video on a computer network, taking into account important parameters such as packet rate, channel capacity, channel length and the number of nodes in the network. The corresponding graphs and drawings were shown, as well as the appropriate conclusions regarding the application of this method in practice were drawn.