Shitikova I. Mathematical modeling and optimization of the heat exchangers of the coiled type constraction

The thesis is dedicated to the relevant issue of the heat supplying systems work and exploitation effectiveness promotion at the expense of new resource saving technologies development and implantation, optimization of the existing heat exchanging devices constructions and implantation of the new ones. Mathematical models of the heat exchangers of the coiled type for the independent heating and hot water supplying systems from the local heating station with the heating-accumulating unit, with the help of which the mathematical model of the heat-exchanging devices constructional parameters calculation has been obtained, have been developed. The general mathematical model of the heat exchanging process for the heating-exchanging unit with three-circuit heat exchanger, the usage of which gives the opportunity to optimize the constructive parameters of the heat exchangers, has been developed. The simulation modeling system, that allows to design a wide range of the heat exchanging processes with the graphic interpretation of the received results and allows to optimize the heat exchanging devices parameters in the interactive mode unlike the existing systems, has been constructed. The experimental researches of the heat exchanger of a coiled type work have been fulfilled on the full-sized pattern. The experiments results gave the opportunity to settle the temperature relations of the primary contour and two secondary ones with the constructive parameters of the heat exchangers of various constructions. The obtained relations propriety is verified with the computational modeling results. A new construction of the heat exchanger of a coiled type, with the help of which it is possible to obtain the heat productivity increase at the expense of heat exchange intensification at one and the same surface in independent heating and hot water supply systems, has been proposed for the systems of local or centralized heat supply from the local heating station with the heating-accumulating unit. The range of heat exchangers original constructions has been optimized on the basis of the built full-sized experimental-investigative stand of the three-circuit heat exchanger with the accumulating capacity. As a result of the experimental researches and computational modeling the recommendations for the practical usage of the heat exchangers of a coiled type with the heating-accumulating unit have been developed on principles of the energy saving technologies.