Hydrodynamics and Heat Transfer Characteristics of Drag-Reducing Trimethylolethane Solution and Suspension by Cationic Surfactant
Phase-change slurry is a promising fluid for a district heating and cooling system. In this work, hydrodynamics and heat transfer characteristics of drag reducing trimethylolethane (TME: CH<SUB>3</SUB>C(CH<SUB>2</SUB>OH)<SUB>3</SUB>) solution and suspension by cationic surfactant were studied. Oleyl bishydroxyethyl methyl ammonium chloride (trade name: Ethoquad O/12) was used as the surfactant, while sodium salicylate (NaSal) as counter-ion. Two kinds of experiments were conducted, namely pressure drop/friction factor and heat transfer measurements. From friction factor measurements, it is found that surfactant can induce drag reduction (<I>DR</I>) in TME solution/suspension. It is also found that TME molecule reduces the <I>DR</I> capability. From heat transfer measurement, it is found that surfactant induces heat transfer reduction (<I>HTR</I>) in TME solution and suspension. It is also revealed that Colburn analogy cannot be applied for TME suspension or drag-reducing TME solution and suspension. By using a correction factor for the Colburn analogy, application of the analogy for the drag-reducing TME solution is improved. At low velocity, <I>HTR</I> is higher than the <I>DR</I>, but at high velocity (just before <I>DR</I> is lost) both <I>HTR</I> and <I>DR</I> are nearly the same.
- Journal of chemical engineering of Japan
Journal of chemical engineering of Japan 39(6), 623-632, 2006-06-01
The Society of Chemical Engineers, Japan