Theoretical Study on Optimum Tube Arrangement in Shell and Tube Heat Exchanger

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This project was carried out to clarify the flow and heat transfer characteristic in tube banks, and to obtain expressions for the heat transfer coefficients and pressure coefficients which may be used for the design of shell and tube heat exchanger. Two-dimensional Navier-Stokes and energy equations were solved numerically. in the calculations, temperature dependent viscosity is considered and k- two-equation model is applied for turbulent flow regime.The main conclusions of this study and the problems to be solved are as follows:(1) For laminar flow regime, the effects of tube arrangements and heating conditions of tubes (uniform wall temperature or uniform wall heat flux) on pressure and local heat transfer coefficients are clarified quantitatively.(2) Temperature dependent viscosity has large effects on flow and heat transfer characteristics and a reference temperature to estimate viscosity should be determined to obtain dimensionless correlation expressions for these characteristics.(3) The usual k- two-equation model of turbulence may be applied for flow in tube bank, however, it is very difficult to obtain the accrate results. the convergence and the heat balance become much poorer than laminar flow.(4) To improve the accracy of numerical solution and to obtain dimensionless expressions for pressure and heat transfer coefficients are remained to be solved in near future.