Analysis of Heat Exchangers Used in the Integrated Gasification Combined Cycle Process

摘要

A shell-and-tube heat exchanger that is widely used for the heat recovery of syngas in a coal gasification system is investigated. FLUENT6.1 software was used, and the renormalization group κ-ε turbulence model was adopted for modeling turbulent flow. The porosity rate, the distribution of the resistance, and the distribution of the heat source were introduced to FLUENT by coupling the user-defined function. The variation of local heat transfer was studied under the effects of the inlet velocity and the arrangement of the baffles. The result shows that a porous media model can be applied in the shell side of a syngas heat exchanger in the integrated gasification combined cycle. The pressure gradient is not directly related to the inlet mass flow rate. The heat transfer of the second half of the shell side becomes stronger with the increase of the inlet mass flow rate. Widening the space between the baffles has more effect in decreasing the resistance and heat transfer than shortening the height of the baffles.