An Optimal Design Method In Consideration Of Structure-size And Performances For A Finned Tube Heat Exchanger

As a device of transferring thermal energy, heat exchangers are widely used in the field of industry. Their performances are directly connected with the effective using and transferring of energy. So analyzing and evaluating its characteristics and optimal design are importance and have engineering valuable. This paper specifies the characteristics of some Optimal design Method of heat exchanger and the academic basic of usable energy loss rate analysis of process. An expression for optimal surface matching of a heat exchanger is derived based on the heat transfer equation and the investment equation under the condition of minimum investment cost per unit heat flow. Another expression for the optimal heat transfer coefficient ratio is obtained under the condition of minimum exergy loss rate of the heat transfer and fluid flow. Performance optimization of the heat exchanger can then be achieved with overall consideration of the heat transfer and flow characteristics as well as the primary investment.Relevant optimal parameters are obtained so as to give the lowest operating cost and least investment.An Optimal design Method of finned tube heat exchanger has been given, in which the structure characteristic and performances of the fluid flow and the heat transfer have been considered comprehensively. In order to achieve the design work the optimal match relationship between the ratio of heat-transfer surfaces and the ratio of convective heat-transfer coefficients has been derived under the condition of the maximum heat transfer rate for given heat exchange area, and the optimal flow parameters relative to structure size, heat flux and physical properties, have been obtained by the analyzing the usable energy loss rate of the fluid-flow and heat-transfer processes of the exchanger, as well as the optimal structure size relation with the heat transfer performance has been introduced for obtaining the maximum heat flow subject to a given heat transfer structure Then the optimal design can be executed by the linkage of above three relationships and by the utilization of iterative data. Therefore the Synthetic performance optimization for considering the structure size, fluid flow and heat transfer can be completed in the design stage of the heat exchanger by the new design method. And this paper presents the detailed optimization method and example. Finned tubes Heat Exchanger Design Software (FHEDS) is presented. FHEDS can process finned tubes heat exchangers' design, data processing and other useful work.