지역냉방시스템에의 적용을 위한 마찰저항감소 첨가물 특성 연구

초록

The district heating and cooling offers a high efficiency of energy utilization and a merit in its maintenance by utilizing centralized heat management. Large pumping power, however, is required because the water has to travel long distance from its heat source to users. In the present study, it is investigated that by adding a very small quantity of drag reduction additives to the District Cooling system it becomes possible to obtain a significant drag reduction and less pumping power for the distrcit cooling system. Water-soluble polymers, surfactants, and environmentally-friendly degradable polymer are utilized as effective drag reducing additives. Experiments have been carried out for water velocities, and percent drag reductions are compared with various additive solutions as a function of circulation time at 100wppm concentration. In case without SDS as an anionic surfactant, copolymer was most effective in percent drag reduction. In case of mixing copolymer with SDS, it is found that there exists an optimal conditions. It is found that environmentally-friendly degradable polymer, xanthan gum can be also considered as significant drag reduction additive. In ice slurry system, it is found that the system gives less pressure drops compared with chilled water system in a certain conditions. And, drag reduction additive was also effective for the case of adding drag reduction additive to ice slurry.