Locating the Temperature Switch for a Drag Reducing Solution

Abstract

Low-cost and environmentally friendly district heating has become a popular trend in northern Europe. These systems use excess heat from plants or factories to heat water, which is then used to supply heat to homes and buildings in the surrounding area. To decrease costs in these systems, studies have shown that a drag reducing surfactant additive can be added to the hot water in order to increase the flow rate without requiring additional pumping energy. However, due to their tendency to reduce turbulent mixing, drag reducing solutions are not typically effective heat transfer fluids. For this reason, it is desirable to develop drag reducing solutions with switchable properties such that they will be drag reducing in part of the district heating system and non-drag reducing in other sections. In this study two solutions were developed showing less than 1 degree Celsius temperature switchability.