Analysis Of Simulation And Optimization On Heat Transfer In Shell-and-tube Heat Exchanger

The previous studies on shell-and-tube heat exchanger focus on analysis of various factors that affect heat transfer. Several methods are utilized to enhance heat transfer of shell-and-tube heat exchanger, namely, magnification of heat transfer area, enlargement of the range of temperature and intensification of heat transfer coefficient. However, due to the limitation of site, equipment and fund, they can not be enlarged unrestrictedly. Therefore, the direction of heat transfer of shell-and-tube heat exchanger is about how to improve the effects of heat transfer through controlling heat transfer coefficient. In the process of utilizing the heat exchanger, since the detached thermal resistance constitutes the total thermal resistance, it is necessary to analyze the detached one in order to change heat transfer coefficient. The side of tube helps to change the inside shape of heat transfer tube and increase the things of disturbing fluid, and numerous factors affect thermal resistance. Thus, it attracts more attention to change structural elements and increase the heat transfer coefficient. This thesis employs unit module in process simulation software Aspen Plus and finite element simulation software Fluent to analyze the heat transfer state of shell in shell-and-tube heat exchanger.This thesis summarizes the studies on shell-and-tube heat exchanger at home and abroad, suggests the developmental trend, introduced and analyzes the thermodynamics theories of shell-and-tube heat exchanger. It applies to property database in Aspen Plus and heat transfer unit module and selects proper property method to conduct simulation analysis on various tubes, namely, three types of heat transfer tube (light tube,2mm high fin tube, lmm high fin tube), two tube patterns (triangle, rotated triangle), three pitches (30mm,28mm,26mm), three types of rod baffle pitch(400mm,240mm,170mm). It analyzed and compared heat transfer coefficient under different circumstance.At the meantime, this thesis applies to finite element simulation software Fluent to conduct numerical simulation research with rod baffle ditch (400mm,240mm,170mm) of shell-and-tube heat exchanger, as well as different ditches in fluid unit channel. Finally, it improves a case study on shell combination.The thesis makes a comparison of related parameters in thermodynamics between process simulation software Aspen Plus and numerical simulation software with the same structure of heat exchanger. It reveals the discrepancy is less than12%.