Heat Exchanging Performance Research And Structure Optimization Of Shell-Tube Heat Exchanger

Heat exchangers are widely used in many industrial fields such as chemical industry, oil industry, power industry, food industry, light industry, atomic energy industry, pharmaceutical industry, aviation industry. Heat exchangers play an important role in the industrial. Shell-and-tube heat exchanger has many advantages such as reliable structure,mature technology and good adaptability, so it is the mostly used structure at home and abroad. In order to improve the comprehensive performance of heat exchangers, the enhanced heat transfer tubes of the special-shape tube is researched. Tube-sheet is the most important and complicated part of the heat exchange. In the normal work, it determines the economic and security of the whole heat exchanger, Tube-sheet is respectively under different pressure and temperature. Therefore, the rational design of the tube-sheet is very important on the safe operation of equipment.In this thesis, research works are done as follows. First of all, in order to improve the comprehensive performance of heat exchangers, the heat transfer performance of smooth pipe, corrugated pipe and spiral corrugated tub are researched. Under the same condition of design of parameters and structure parameters, the smooth pipe heat exchanger, corrugated tube heat exchanger and the spiral corrugated tube heat transfer coefficient of heat exchanger, the pressure loss and the Nusselt are compared; Secondly, fluid dynamics analysis of the heat exchanger is done by the finite element analysis software ANSYS FLOTRAN CFD analysis module in shell side, the shell side fluid layer distribution of the heat exchanger is researched, the effect between baffle spacing and fluid properties on heat exchanger shell-side heat transfer coefficient are discussed; thirdly, the tube-sheet of heat exchanger for steady temperature field analysis and thermal stress analysis are done by ANSYS software, Considering the complexity of the structure, the model of tube-sheet is simplified when it is established. The temperature field and thermal stress of the heat exchanger are calculated, Then according to the JB4732-1995<Steel pressure vessels--Design by analysis>, stresses in results of finite element analysis are assessed. Finally, the tube-sheet structure of heat exchanger is optimization. The thickness of tube-sheet is cut. The improved tube plate structure meets the strength requirements. The design of tube-sheet is safe and reliable.This analysis results can be used as useful reference data to optimized design in the complex heat exchanger.