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With the development of industry and subsequent urbanization which is transforming even the most obscure corners of any country into comfortable places to live, the problem of the coexistence of modern power complexes and environmentally safe living conditions is exacerbated. Finding a compromise between environmental and economic indexes and selecting the best versions of water use for both large industrial complexes and for individual "small" plants are primarily correlated with creating equipment that satisfies a number of requirements imposed by the client.Countries with minimal water supplies and limited living spaces naturally began to solve the first problem of "water cooling" of industrial and power plants. In Western Europe and the Near East, systems for direct cooling of power units with water from rivers, lakes, and cooling towers began to be replaced by so-called "dry"cooling towers -units that cool the water required for a manufacturing process in a closed cycle without using open bodies of water or by partially using them at peak loads."Dry" cooling towers from GEA -EGI Contracting/Engineering Co. Ltd. (Germany), Energetika Co., and others are used in different countries of the world.We will briefly examine the use of cooling towers of a different type. "Wet" cooling towers were initially created as direct-contact condensers. They arose as a result of attempts to create cooling systems that would occupy small areas. Another advantage of these cooling towers in comparison to systems that directly divert water from bodies of water is approximately five times lower water consumption for the same thermal load.The principle of "wet" cooling towers consists of the following. The water circulating in the closed loop of the cooling tower is sprayed over the entire area by sprayers and is cooled in atmospheric air. This water cooling system is most effective at high atmospheric air temperatures.The "dry" cooling tower that totally eliminates water losses could be an alternative to the classic "wet" cooling tower. The water in it is cooled by atmospheric air through a heat-exchange surface for which both a plate and a tube system is used. At hot times of the year, this system cannot always ensure cooling due to the small temperature gradient between the media.

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Air cooling equipment (ACE) of traditional design -AVG and AVZ with a ribbed pipe heat exchange surface, have a number of important drawbacks due to the horizontal position of the 12-m tubes, as extensive experience in using them has shown: • • • • • sagging of the tubes and formation of a "dead" zone for heat-carrier overflow during operation and thawing of the tubes on shutting down, which subsequently results in important breakdowns; • • • • • the need for large areas for installing them and the use of fans with lower-speed electric motors and large rotors; • • • • • the decrease in cooling efficiency in the condensation mode; installation of heat-exchange sections in the shape of a "cabin" (zigzag) causes uneven distribution of cooling air flow and parasitic leaks;• • • • • uneven expansion of the tubes rigidly fixed to the collectors due to uneven distribution of media in the intra-and intertube spaces so that the tubes buckle or crack in the region of connection; the same effect is observed in the starting and transitional modes.The analysis of these drawbacks demonstrated the necessity of using ACE of more up-to-date designs for the newly constructed catalytic cracking plants (customer -TAIF -NK Co., general designer -VNIPIneft').Anod -Teploobmennyi Tsentr (TTs) Ltd. (Nizhnii Novgorod) is designing and manufacturing heat-exchange equipment for the energy, petrochemical, transport, and other branches of industry.This equipment is designed to operate with different media -any liquids and gases at pressures up to 20 MPa, temperatures up to 600C, and cyclic loading. The material of the heat-exchange surface are selected in consideration of the operating conditions, assigned life, and cost indexes.The new design of the heat-exchange surface -made of coils with a small bend radius (Fig. 1) -is based on the developments. This design has much better specifications than the straight-tube, plate, and ordinary coil designs. Let us consider its advantages.