EFFICIENCY IMPROVEMENT OF THE HEAT EXCHANGER "PIPE IN PIPE"

Heat exchangers of the “pipe in pipe” type are fairly common tubular heat exchangers in the chemical, oil refining, food, heat and energy, and related industries, they effectively operate in a large pressure range and are characterized by a lower hydraulic resistance of the annulus compared to shell-and-tube heat exchangers. Due to the significant speeds of movement of coolants that can be achieved in such devices, an increase in the coefficients of heat transfer and slowing the deposition of contaminants on the walls of pipes is ensured. The advantage of these heat exchangers is also the possibility of assembling them at the workplace by increasing or decreasing the number of sections depending on the parameters of the technological process [1]. Heat exchangers "pipe in pipe" can be made non-separable and collapsible. Non-separable single-flow heat exchangers are used for clean coolants, have no deposits, that is, then there is no need for mechanical cleaning of the surface of heat exchange tubes from contamination. Folding single-flow heat exchangers provide the ability to extract heat exchange tubes for their replacement or mechanical cleaning outside the apparatus. Also, in addition to traditional metals and alloys, various polymeric materials are increasingly being used for the manufacture of heat exchange equipment. Including compositional, whose properties can be predicted at the development stage of their composition [2]. Traditional designs of tube-in-tube heat exchangers have been developed in production and operation, but even they need to be improved. Therefore, research on the modernization of heat exchange equipment continues today. Further, the improved designs of heat exchangers of the “pipe in pipe” type proposed by the staff of the National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” are considered.