Abstract
The flow drag and heat transfer reduction effects of brine flow with drag reduction surfactants have been investigated in order to conserve the energy in a district heating and cooling system. In this study, Ethylene Glycol (EG) solution with Oleyldihydroxyetyl Amine Oxide (ODEAO) was used as a drag reduction brine solution with surfactant. And the pipe friction coefficient and mean heat transfer coefficient of the EG solution flow with ODEAO were measured as parameters of EG concentration, solution temperature and ODEAO concentration. The experimental results indicated that the flow drag (heat transfer) reduction effect was lost when the wall shear stress exceeded a certain value. And the certain value of this wall shear stress (= maximum wall shear stress) increased with increasing the EG concentration, ODEAO concentration and brine temperature. On the other hand, the drag reduction mechanism of EG solution with ODEAO was investigated by comparing with the experimental results the ODEAO water solution
