A NUMERICAL ANALYSIS FOR THE FLOW AND HEAT TRANSFER IN A LARGE PLATE HEAT EXCHANGER BY USING A POROUS MEDIA APPROACH

摘要

A numerical analysis was conducted to investigate the flow and heat transfer in a large plate heat exchanger. For the purpose of investigation on the whole flow field inside a large plate heat exchanger, the microscopic method by using actual geometry is not practical since it requires huge computational resources. In the present study, a semi-microscopic method by using a porous media approach has been adopted in order to predict the overall flow and heat transfer performance for the large plate heat exchanger. The pressure drop and heat transfer characteristics of the flow passages inside the heat exchanger was obtained first from the microscopic simulation for the flow inside passages and heat transfer through the plates by using the detailed geometry of one representative repeating section of the heat transfer plate. These results were used as characteristics of the porous media replacing the complex flow passages to simulate the large plate heat exchanger as a whole. The overall performance predicted from the semi-microscopic method agrees well with available experimental data. The numerical method in the present study can be applicable to the different types of large heat exchangers that have complex geometry in order to predict the overall performance.