抄録
Drag reduction caused by cationic surfactant solutions is considered to be an effective way to reduce the running cost in closed-loop district heating and cooling systems. Conversely, much research has pointed out that heat transfer reduction occurs simultaneously for drag reducing flows. In this study, heat transfer characteristics were measured for drag-reducing additives with two cationic surfactants (Ethoquad O/12 and Ethoquad O/13) using a test loop equipment and a practical air conditioning system. From the results, significant decreases of heat transfer coefficients were observed for drag-reducing additives, however, temperature difference between the inlet and outlet of the test section can not be decreased compared with that of water.
