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Vol 106, No 7 (2017)
- Year: 2017
- Articles: 10
- URL: https://freezetech.ru/0023-124X/issue/view/5077
Articles
Solnechnoe kholodosnabzhenie. 34ya informatsionnaya zapiska po kholodil'nym tekhnologiyam (aprel' 2017 g.)
Refrigeration Technology. 2017;106(7):4-7
4-7
Unikal'nost' deyatel'nosti gruppy kompaniy GEA v Rossii
Refrigeration Technology. 2017;106(7):8-10
8-10
Povyshenie energoeffektivnosti kholodil'nykh ustanovok pri umen'shenii temperaturnogo napora v teploobmennikakh
Refrigeration Technology. 2017;106(7):11-12
11-12
Kompressory i elektronnye komponenty BITZER stanovyatsya odnim tselym
Refrigeration Technology. 2017;106(7):13-25
13-25
Novye komponenty becool
Refrigeration Technology. 2017;106(7):26-29
26-29
Sistemy konditsionirovaniya vozdukha i vozdushnye konditsionery dlya proizvodstvennykh pomeshcheniy
Abstract
Now owing to manufacturing development and improvement air conditioners and air conditioning systems designed for production areas are of great importance at modern industrial enterprises. The power loading on these systems and air conditioners is continuously increasing, requirements are toughening as well but operation conditions become harder. The paper examines new designs of air conditioners and air conditioning systems to be used in production areas that have enhanced characteristics and are offered in patents and scientific and technical literature of developed countries. The main tendencies of development of air conditioners and air conditioning systems design are shown.
Refrigeration Technology. 2017;106(7):30-36
30-36
Teploprovodnost' ineevogo krioosadka kak faktor, opredelyayushchiy teploperedachu v kamernykh priborakh okhlazhdeniya
Abstract
Frost formation on lowtemperature surfaces of heatexchangers is a process that reduces the efficiency of a number of refrigeration machines and devices. One of the most important parameters that affect the accuracy of mathematical modeling of the process of nonstationary frost formation is thermal conductivity of frost layer and its correlations. It is necessary for thermal and hydraulic design of equipment. The existing correlations of different researchers are correct in narrow ranges of temperatures and humidity; only a few of them are suitable for use in low temperature engineering. The correlations in the present work determine the thermal conductivity of the depositing frost layer, taking into account the effect of temperature on its structure. They are based on the correlations of the local thermal conductivity of frost from its local temperature and density and thereby increase significantly the accuracy of calculations of the coefficient of thermal conductivity of the frost layer in a wide range of temperatures for densities of the frost less than 300 kg/m3.
Refrigeration Technology. 2017;106(7):37-41
37-41
O vazhnosti ucheta faktora L'yuisa v raschetakh protsessa isparitel'nogo okhlazhdeniya v apparatakh protivotochnogo tipa
Abstract
The author approach to calculation of the evaporation cooling process in the bank of tubes of apparatuses of refrigeration systems is presented. One of the particularities of the approach consists in the refuse of admission to be equal to the Lewis factor unit. It is established that the Lewis factor is a basic characteristic when analyzing the heat and mass exchange process; it allows explaining the character of the behavior of temperature and humid parameters of a waterair medium in the apparatus. The study carried out resulted in the offer to take into account the Lewis factor when calculating the coefficient of heat transfer from the wall outside towards the film of spraying water. Also it is offered to use the procedure based on taking into account enthalpies of humid air and spraying water in the apparatus as well as the information of the construction of the bank of tubes to define the quantity of heat transferred from a coolant (refrigerant) flowing in the coil of bank of tubes to a waterair mixture in the apparatus. The efficiency of organization of evaporation cooling processes in modern refrigeration systems was estimated.
Refrigeration Technology. 2017;106(7):42-47
42-47
Smesevye khladagenty na osnove GFO
Abstract
According to ЕС 517/2014 Regulations and Paris agreement on fluorinecontaining greenhouse gases a gradual phaseout of HFC refrigerants is expected. One of the variants suggested to replace them are mixtures on HFO (hydrofluoroolefines). The paper presents thermophysical properties and environmental indices of refrigerant mixtures on HFO meant for HFC refrigerants replacement. The results of comparative testing of refrigeration systems operating on HFC and HFO refrigerant mixtures are cited.
Refrigeration Technology. 2017;106(7):48-53
48-53
Vysokoeffektivnyy teplovoy nasos-vodonagrevatel' na smesevom khladagente CO2/ R32/ R134a
Abstract
The paper deals with the urgency of use and finding of new refrigerant mixtures that are, in particular, applied for heat pumps. To obtain high conversion efficiency an optimal composition of the CO2 /R32/R134a refrigerant mixture as regards thermodynamic and environmental characteristics was selected. Its main advantages as well as disadvantages were shown. Also the cycle of the heat pump was improved by a heat exchange apparatus adding; the last used the heat of rejected water after a consumer. The modeling of cycles using special program packages was carried out. The major graphic dependences and cycles parameters are presented. The improvements listed allowed obtaining the heat pumpwater heater conversion efficiency equal to 15,75. The main conditions to obtain such a high conversion efficiency of the plant are described.
Refrigeration Technology. 2017;106(7):54-60
54-60