Numerical simulation on flow and heat transfer at shell-side of flat-tube heat exchangers

The fluid flow and heat transfer of the shell-side in one type of flat-tube heat exchangers (FHE) were studied through numerical simulation and experimental methods. In the numerical simulation, hot/cold air was set as working fluid, and the standard k-ɛ turbulence model supplemented by boundary conditions was used, and also the control volume method was used to the discrete control equations. Compared with the same type of circular-tube heat exchangers (CHE), the numerical simulation results show that the pressure drop at the shell-side of FHE decreases by 12%–20%, and heat transfer coefficient increases by about 24%. The coefficient of integral performance Nu/ζ ^0.29 has an increment of 22%–34%. Under the same conditions, the experimental results of temperature and the overall pressure drop show that the deviation percentage with those of numerical simulation are less than 8% and 25%, respectively. Both results verify that the heat transfer efficiency and flow resistance characteristics of FHEs are superior to that of CHEs.