The object of the study is the processes of hydrodynamics, heat transfer and fouling formation in the channels welded plate heat exchangers (PHEs). The aim of the work is to intensify the heat transfer processes in hydrocarbon processing technologies by developing a method for estimation of the optimal design parameters of welded PHEs for the recovery and utilization of heat of petrochemical complexes. Methods of research: theoretical methods and experimental data of known scientists published in professional domestic and foreign thematic journals; methods of mathematical modeling and mathematical statistics, the basic provisions of the heat transfer theory and hydrodynamics are used for the analysis of the research results; obtaining the ratio for the thermal resistance of the heat transfer surface fouling is based on the method of determining the level of fouling formation proposed by Epstein; the determination of heat transfer in PHE channels is based on the analogy of heat and momentum transfer for turbulent flow in PHE channels; the energy-saving reconstruction of the heat exchange network for the utilization of waste heat was carried out using the software HENSYN, created within the framework of the European project EFENIS; data processing was carried out using Mathcad and Excel software. Theoretical and practical results: the method of calculation of PHEs, taking into account the dynamics of the heat transfer surface fouling, will allow, at the design stage, to improve the heat transfer networks and to develop a schedule for cleaning the units; on the basis of calculations of two types of welded PHEs and comparison with traditional shell-tubes units, it is proved that the use of the plate type is promising for the position of heating the oil in the crude oil preheat train at the refinery; the scheme of connection of heat exchangers, which makes it possible to use waste heat of the petrochemical complex for the heat supply of the neighboring city has been developed. Scientific novelty: for the first time, the dependence of the heat transfer and the hydraulic resistance in PHEs of welded design with corrugated square and rounded plates with specified geometric parameters of the corrugation, which takes into account the local hydraulic resistance in the flow distribution zones on the basis of the analogy of the heat transfer and momentum transfer, has been obtained, what enabled to develop a method for these heat exchangers design; for the first time was obtained a correlation, which enables depending on the Prandtl number and fluid flow regime in the channels of welded PHEs to determin the heat transfer of a turbulent flow, , which is suitable for the Reynolds numbers in the range from 100 to 20,000 and the Prandtl numbers varying from 3 to 500, which allowes to do the rating design of welded PHEs used for hydrocarbons applications in the whole range of their use; for the first time has been proposed and developed a method, which allows estimating the threshold values of the fouling thermal resistance and its formation during the time, depending on the geometrical parameters of the plate corrugation and the thermo-physical properties of the heat carrier, which allowed to predict the heat transfer and hydraulic parameters of welded PHEs; the method of PHEs preliminary design has been further developed, allowing to design single pass welded PHEs with rounded plates and multi-pass welded PHEs with square plates purposing to obtain the units with minimal heat transfer area. Degree of implementation: the results of the performed work were implemented at the IPLOM oil refinery (Busalla, Italy) in scope of EU funded project EFENIS and at AT «SPIVDRUZHNIST-T» company, Ukraine; the recommendations for the main design parameters for the standards and manuals for heat exchangers design were implemented at the NPVF "Ankor-Teploenergo" industrial enterprise; the results of the PhD work are used in the educational process of the Department of Integrated Technologies, Processes and Apparatuses of NTU "KhPI" in the teaching of disciplines "Processes and Apparatuses of Chemical Production", "Fundamentals of Energy and Resource Saving". Scope of use: chemical, oil refining and related industries.
