Vol 91, No 5 (2002)

The Concept of the State policy in the field of healthy nutrition of Russian population for the period up to the year 2005 and approved by the decree of the Government of the Russian Federation in the year 1У9Я had a great impact on the development of sciences associated with agriindustrial complex (АIС) in accordance with the main directions of the Concept was specified a structure of the subprogram "Perspective processes in processing industries of АIС which is a part of the special federal scientific and technical program "Research and development on priority directions of development of science and technique of civil application”.

Under this sub-program fundamentally new technological systems, ensuring the intensification of processes of chilling and freezing, increasing storage time of perishable foods, reduction of their losses and decreasing the velocity of oxidation processes have been developed.

A cryogenic method of products freezing by liquid and gaseous nitrogen using a non-mechanical flow-through system of cold supply was developed.

The importance of problems of agricultural materials and food products storage is confirmed by the fact that this direction has been included into the list of priority directions of development of science and technology in AIC for the period 2001-2005 years.

At the present time the preparation of the program on solving the storage problems in the processing industries of AIC is being implemented within the federal special scientific and technical program “Research and developments on priority directions of science and technology” for the period 2002-2006, as approved by the Government of the Russian Federation as a result of competition, carried out by the Russian Ministry of Science.

One of the new developments of the company “Clivet" - a system with a "water loop" which can become an alternative to systems with controlled flow rate of refrigerant and carrying of heat and cold between rooms, lit system with a "water loop" is a decentralized system of air conditioning with the utilization of heat which allows to simultaneously heat and cool different rooms in multi-zone or multifunctional buildings.

The system consists of three main components:

• monoblock air conditioners with a heat pump and water condenser;
• water contour (loop) with its pump assembly and accumulation tank;
• sources of refrigeration (cooling tower) and heat (boiler) Since the optimum temperature of water in the contour is 18...35C, refrigeration can be accomplished in heat exchangers (dry cooling towers) that are taken out.

To fulfill these goals "Clivet" company is producing all the necessary equipment: terminal blocks of different types and capacity - console, channel, cabinet, roof. The monoblock air conditioner is a refrigeration unit including all the elements of refrigeration cycle: compressor, water condenser and evaporator. Pie air conditioner can be installed either directly in a room, like a fan-coil unit, or outdoors, it has a built-in control and provides refrigeration or heating in a particular room. As distinct from most of the individual heat pump systems, the system with a "water loop” can be most advantageously used in the countries with cold climate, for example of Northern Europe, and in Russia. And the economical efficiency of the system with "water loop" is considerably higher, than that of freon multi-zone systems.

Аn intercooler in a compound system is to cool the discharge ammonia vapor between stages. This is usually done by bubbling process through a bath of liquid ammonia, and inevitable pressure drop- occurred. Slugging is the most dangerous break-downs with ammonia compressors and more frequenth happen at the high-stage e.g. after an intercooler. The direct contact evaporating cooling device and the heat compression effect has been used instead of bubbling open (and closed) type intercooler. Hit piping diagrams have been shown: for single unit, for several compressors with individual and commn intercooler, for compound system and for seasonal low temperature supply when some addition compressors are possible to use.

Alfa Laval offers the new AlfaGreen series of air condensers and fluid coolers for refrigeration and air conditioning applications.

OAO Nizhnekamskneftekhim is operating ammonia turbo-compressor units ATKA-545 and ATKA-445 of high capacity since June 1975. The machines with the first serial numbers came to the construction site in 1974.
The decision made by the designer (Giprokauchuk) to implement domestic equipment instead of expensive imported equipment in multi-tonnage production of synthetic rubbers was justified. Technical and repair base, material and human resources allowed performing this task at Nizhnekamsk petrochemical plant. As time showed, mastering of new refrigeration compressors in other regions of the country was very difficult. The technological chain of petrochemical productions is an interconnected structure, if one of its links is unstable, the whole production stops. Timing of mastering the new equipment was complicated by the specifics of production. There was no experience in installation, adjustment and operation.

The new book, prepared by a team of authors, is of interest to refrigerators, students and even people unfamiliar with the intricacies of operating or repairing small refrigeration and air conditioning systems, but who have such refrigeration units in their household. The book consists of introduction, 6 chapters, conclusion and references.