Evaluation of Surfactant Drag Reduction Effect in a District Heating System

Abstract

A scale-up method proposed by Hoyt was used to evaluate the flow resistance of working fluid in a district heating system (DHS) after a surfactant drag reducer, CTAC/NaSal, was added. The measured drag reduction data of 100 ppm surfactant solution obtained from an 18.5 mm diameter pipe in the laboratory were used for the evaluation. The results show that the reduction of the pressure drop in the system reaches 23.28% by the addition of surfactants, indicating a very good energy saving effect and application prospective. Comparing with the effect of 100 ppm solution, it is found that the drag reduction will not be further improved obviously in the system with increasing concentration. It was also found that the local pressure drop takes a large proportion in the total pressure drop of the DHS, which could not be reduced by adding the surfactants.

Investigation of the drag reduction of hydrolyzed polyacrylamide–xanthan gum composite solution in turbulent flow

“…At present, as an effective energy‐saving approach, the drag reduction technology by additives has the advantages of significant drag reduction effect, simple operation, and low cost and has been researched and applied extensively. Hence, further research and development are of vital importance to the transportation industry 1–4 …”

“…Hence, further research and development are of vital importance to the transportation industry. [1][2][3][4] Since Toms 5 observed that adding a small amount of polymer to the fluid can reduce turbulence resistance, researchers have developed a variety of drag reducers, mainly including polymers and surfactants. Polymers play an indispensable role in the petroleum industry due to their high drag reduction properties.…”

Direct numerical simulation of surfactant solution flow in the wide‐rib rectangular grooved channel

“…Wei et al 15 used the particle image velocimetry (PIV) technique to investigate the turbulent structures of surfactant solution and found that the formation of small-scale vortices was inhibited by adding the surfactants, implying a large-eddy environment which could provide an excellent condition for other drag-reducing methods related to the vortex scale. Furthermore, Ma et al 16 and Tsukahara et al 17 both reported that the drag reduction and heat transfer performance of surfactant restrain each other, which limited its application in the field of heat transfer. Wang et al 18 reported that the drag reduction performance of surfactant solution was lower at a low Reynolds number (Re < 10,000), due to the lower shear stress and the weaker shear-induced structures, which limited the application of surfactant solutions in the field of low-speed.…”