Vol 92, No 1 (2003)
Articles
The concept of long-term artificial development in the field of refrigeration
Abstract
The world community, under the auspices of the United Nations (UN), is pursuing a vision of long-term development, defined as "development that meets the needs of the present without compromising the needs of future generations. The World Summit on Sustainable Development, held in Johannesburg from 26 August to 4 September, was a truly global event: the largest conference ever organized by the UN, bringing together more than 70,000 participants. Nearly 100 heads of state attended the summit.
The International Institute of Refrigeration (IIR), commissioned by the United Nations Environment Program (UNEP), prepared the report on refrigeration in light of the UN's Long-Term Development Concept especially for this conference. Such reports were presented in 21 other areas of human activity, including metallurgy, chemistry, oil and gas sector, food industry, etc., as well as transport, construction, energy, information technology, etc.



Energy and economic advantages of combining autonomous heat sources of buildings with sources of cooling air conditioning systems
Abstract
The energy and economic advantages of uniting the self- contained sources of heat supply of buildings with the sources of refrigeration supply of air-conditioning systems (SKV) are shown in the article. The example of calculation of annual expenditures for refrigeration supply of SKV from vapour-compression refrigerating machine and from absorption lithium bromide machine, working on waste heat has been considered.



Devices for injecting liquid ammonia into thermopressor coolers
Abstract
The survey of works, which were carried out in thermal engineering, and related to characteristics of mixing contact heat exchangers is given, the condition to calculate nozzle diameter to inject liquid ammonia into evaporating chamber of thermopressor type intermediate cooler is shown. The properties of devices for liquid atomizing are considered, Laval nozzle has been grounded on the principle of discrete pulse energy input and transformation for injection and atomizing of adiabatically boiled up ammonia flow. The description of experimental layout is shown, also results, comparisons and conclusions are presented, calculated diameters presented in the table.



New generation refrigerants
Abstract
The paper is devoted to ecologically clean heat-carrying and cold-carrying media of new generation. The substances ecosol and ecofrost can be considered as serious alternatives to toxic and corrosion-dangerous cold-carrying media of the type ethylene glycol and trichloroethylene.
The paper presents thermophysical properties of new substances and offers recommendations on temperature ranges of their use in refrigerating equipment.



Thermal conductivity of R401B refrigerant. Experiment and generalization
Abstract
Heat conductivity of R401B - a transition working substance which can be used instead of R12 in the existing refrigerating installations - has been experimentally investigated. The results of the experiments have been generalized and presented in analytical form. The error of measurement has been assessed.



Grasso's newly developed economizer system for two-stage compression
Abstract
More than 150 years of experience in the design and manufacture of reciprocating compressors and compressor units based on them reliably ensure Grasso's leading position in the world of refrigeration engineering.
According to statistics, at least 65% of all two-stage piston compressor units produced are equipped with an intercooling system of one type or another upon customer request.






Fast freezing of foodstuffs through hydrofluidization and pumped ice slurries
Abstract
The paper is devoted to the so-called HydroFluidisation Method, recently suggested and patented by the authors to bring together the advantages and to overcome the drawbacks of both air fluidisation and immersion food freezing techniques. Two main innovative aspects can clearly be distinguished: (i) employment of unfreezable liquids as fluidising agents and (ii) use of pumpable ice slurries as fluidising media. This freezing principle provides an extremely high heat transfer rate, short freezing times, great throughput and better product quality at refrigerating temperatures maintained by a single-stage refrigeration machine. Thus, nearly two times lower investments and power costs are necessary as compared with the popular individual quick freezing methods. Moreover, such hydrofluidisation freezing systems are less hazardous from the environmental viewpoint, since the refrigerant is closed in a small isolated circuit only. Some collaborative research activities directed towards the method's development and implementation within the European Union are also outlined.



Thermal insulation for refrigeration and air conditioning systems
Abstract
Currently, two types of thermal insulation materials are widely used in refrigeration and air conditioning systems - foam rubber (elastomers) and foamed polyethylene. Let's compare these materials by the way they are used and their effectiveness.



New technical manual from Alfa Laval
Abstract
Alfa Laval, as a leading company in the heat-exchange equipment market, is constantly generating new technical and design solutions. In addition, there is a wealth of theoretical and practical experience that is actively used by the company's partners in their operations.
The question was often raised by customers: "Why not systematize the experience accumulated by Alfa Laval in a book? That way, the design, installation and servicing of equipment can be covered in one book".



Technical Committee on Standardization No. 271 "Refrigerating Units" at Gosstandart of Russia
Abstract
We have already informed earlier on the changes in the management and secretariat of TC 271, which were approved by the Order of Gosstandart of Russia No. 161 of July 8, 2002. (see XT № 9/ 2002, p. 28).
In December 2002 the first meeting of renewed structure of TC 271 was held by its chairman, director general of OJSC "VNIIholodmash-Holding" O.M. Tagantsev. More than 30 specialists from 16 organizations including new members of TC 271 such as Gosgortechnadzor of Russia, Khimkholodservis NPF LLC, Refrigeration Engineering Journal and others participated in the work of the Committee.



Multi-compressor refrigeration units. Oil distribution problems
Abstract
When the number of compressors running in parallel is equal to or greater than four, or when the compressors have different capacities (although parallel connection of compressors of different capacities and designs must be avoided), or the amount of oil returned is unknown, an oil level regulator (OLR) and oil separator (OS) system is preferable. With this system, the difference in pressure inside the crankcase of each compressor has no effect on oil level stabilization.



Supermarket refrigeration systems with natural refrigerants
Abstract
Influence of chlorofluorocarbon refrigerants on climate warming has become in recent years a serious concern of both scientists and state officials in different countries of the world.
The main directions of solving this problem at present are measures aimed at reduction of refrigerant leakage from refrigeration systems, reduction of its volume in the system, as well as gradual transfer of refrigeration equipment to operation with such natural refrigerants as ammonia, hydrocarbons, carbon dioxide. This review briefly highlights different aspects of using these refrigerants in supermarket refrigeration systems.





