Study the performance of microchannel heat exchanger with combined effect of PDF and PDF and different flow arrangements

Abstract

   This paper numerically investigated the square microchannel heat exchanger (MCHE) at hydraulic diameter 20 ?m and the diluted water 1:1 potassium chloride (KCl) solution as a working fluid at ionic concentration  M with using silicon microchannel. A comparison has been made between parallel and counter flow with two methods of driven flow of liquid through MCHE (pressure driven flow PDF and electroosmotic flow EOF) with using two values of zeta potential (-75, -200 mv) to investigate the effect of zeta potential on performance of parallel and counter flow. In this paper solved a three dimensional Poisson-Boltzmann equations and Navier-stoke equations with electric field which applied on electrolyte solution have been solved using the finite volume scheme. The results showed that, the total pressure drop increased at combined EOF/PDF compared with pure pressure driven and it clear in parallel flow more than counter flow. Heat transfer rate for counter flow is higher in parallel flow. That the increasing in zeta potential of surface charge caused an increase effect of EDL due to increase in  Helmholtz-Smolochowski velocity