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Vol 105, No 2 (2016)
- Year: 2016
- Articles: 11
- URL: https://freezetech.ru/0023-124X/issue/view/5060
Articles
Integrirovannaya modul'naya sistema konditsionirovaniya Carrier AquaFlowTM VWV s peremennym raskhodom zhidkosti
Refrigeration Technology. 2016;105(2):4-7
4-7
Sistema konditsionirovaniya vozdukha natsional'noy khudozhestvennoy galerei v Yoshkar-Ole
Refrigeration Technology. 2016;105(2):8-13
8-13
Mirovoy rynok chillerov i promyshlennykh konditsionerov vozdukha
Refrigeration Technology. 2016;105(2):14-19
14-19
Sovremennye resheniya s ICF FLEXLINETM na OOO «Yubileynoe»
Refrigeration Technology. 2016;105(2):20-31
20-31
Kelvion - nadezhnye resheniya teploobmena dlya sistem kholodosnabzheniya
Refrigeration Technology. 2016;105(2):32-37
32-37
Rele davleniya serii CS3 dlya sistemy na CO2
Refrigeration Technology. 2016;105(2):38-40
38-40
Vysokoeffektivnye resheniya dlya sistem okhlazhdeniya s ispol'zovaniem frikullinga i rekuperatsii tepla na baze oborudovaniya Climaveneta
Abstract
The problems of the efficient cold supply and recovery of heat release of large data handling centers are examined. In the beginning of the paper the examples of different methods of cold supply are cited, the necessity and economic benefit of heat recovery of refrigeration plants are grounded. Further different methods of cold supply are compared in terms of electric power annual costs using a data handling center at 1 megawatt capacity as an example. The efficiency of the large data handling center operation is analyzed with calculation of the PUE coefficient. The schemes and examples of using recovered heat according to current rates and norms on consumption of services in the housing and municipal sector are given. In conclusion a short list of Climaveneta S.p.A. refrigerating plants with free cooling technology and possible heat recuperation that may be used for a twelvemonth cold supply of data handling centers is cited. So, the article proves with convincing arguments the efficiency of using the scheme with heat recuperation offered for a large data handling center. Keywords: efficient cold supply for a data handling center; chiller; recuperator; free cooling; heat supply.
Refrigeration Technology. 2016;105(2):41-45
41-45
Energosberegayushchaya intensifikatsiya teploobmena rassecheniem dlinnykh gladkikh kanalov plastinchatorebristykh poverkhnostey
Abstract
Testing of platefinned surfaces with interrupted rectangular channels allowed defining the range of the change of current estimations values of a rational enhancement of the convective heat exchange (RECH) Qi = 2,11…2,15...2,78 in the range of the values of criterion Rei = 600…1000...4400 and fin thickness ratio (/d)i = 0,071 … 0,083 ... 0,061. The experiment proved the rationality of the energy saving management of channels operation under conditions of the initial zone of hydrodynamic and thermal stabilization of the flow along with the scale control (/d - variable) of generable vortexes in the thin wall layer at weak diffusion towards the flow core that provided a high increase of the heat transfer coefficient at a moderate increase of aerodynamic resistance. A maximal value of RECH estimation 2,78 at Re = 4400 and (/d) = 0.061 was defined. The results of researches were analyzed in terms of physical mechanisms of the RECH process. Keywords: highdrag fin frontal profile; wall layer; flow core; parameters - fin thickness ratio, degree of channel section narrowing; vortex zone of separation; zone of reattachment.
Refrigeration Technology. 2016;105(2):46-50
46-50
Primenenie ABKhM THERMAX v pishchevoy promyshlennosti
Abstract
Until recently the inability of the absorption refrigerating machines (ABRM) to produce temperatures lower +5 оC was a serious problem that put obstacles in the way of using them in food industry. In 2001 the engineers of the Thermax company (India) removed this obstacle, and since the use of ARM in the field of food production has been actively enlarged. At present the production absorption machines may cool down the liquid to -5 оC temperature that is reached owing to the addition of the lithium bromide solution in water boiling in the ABRM evaporator. The liquid produced doesn’t freeze and keeps its capability to boil at temperature lowering.A special module the core of which is a controller controls the lithium bromide solution concentration. This allows maintaining necessary parameters of the solution at high accuracy including crystallization. The paper examines the world practice examples of successful using low-temperature lithium bromide refrigerating machines in food enterprises.
Refrigeration Technology. 2016;105(2):51-54
51-54
Podmorazhivanie myasa morozil'noy plitoy
Abstract
A mathematical description of the process of a substance phase state change at freezing of any body is presented. It is shown that the duration of the process is defined by the position of the interface between frozen and not frozen parts of the body that is not evidently specified and is displaced in time. The subfreezing is considered as a process of interrupted freezing that is used in many technologies of foodstuffs cold treatment. The analytical solution of the body freezing problem was obtained by Stefan when admitting a great intensity of external heat that should be confirmed experimentally in respect to a concrete technology. An experimental research of the meat subfreezing process at the contact with a freezing plate was carried out. A tolerable matching of results obtained by analytical and experimental methods was established. This allows calculating the thickness of the subfrozen layer or the duration of the subfreezing process as well as defining the temperature field in the body for any moment of time. The possibility of using Stefan’s mathematical model assumes a principal character when the solutions of heat conductivity problems are used as intermediate results for the solutions of other tasks that are more complicated, for example, giving proof of the storage conditions of subfrozen NOR/DFD meat taking into account the quantity of water frozen out. Keywords: meat subfreezing, phase state change at freezing, Stefan’ problem, freezing plate
Refrigeration Technology. 2016;105(2):55-59
55-59
Prodekspo2016
Refrigeration Technology. 2016;105(2):60-64
60-64