Journal of Energy Engineering (에너지공학)

The Korean Society for Energy (한국에너지학회)
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The Degradation of the Effect of Drag Reduction in Synthetic Polymer Solution

합성고분자 첨가제에 의한 마찰저항감소효과의 퇴화에 관한 연구

  • Published : 1998.09.01
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Abstract

Degradation of polymer additives is enhanced at higher temperature of the test solutions. The degradation of Co-polymer solution was investigated experimentally in a closed loop at the temperature of 6$0^{\circ}C$ and 8$0^{\circ}C$ with various polymer concentrations of 100, 200, 400, 600 ppm in order to see the effect of temperature and polymer concentration with time. The degradation effect were found to be more dependent on temperature than mechanical shear. The friction factor versus Reynolds number curves show that in the range of Reynolds number number 50,000~150,000 the friction was decreased as Reynolds number increased and the friction of solution at low temperature approached to Virk's maximum drag reduction asymptote. For constant flowrates and temperatures the degradation effect was found to be less likely in higher polymer concentration. For constant flowrates and polymer concentrations the degradation rates are affected mainly by temperature. At the temperature of 8$0^{\circ}C$ and polymer concentration of 100 ppm, drag reduction effect was disappeared after 4 hours. However, this thermal degradation could be avoided with additional materials such as surfactants which are supposed to enhance the bonding forces between polymer molecules.

고분자 첨가물의 퇴화는 시험용액의 고온상태에서 증가된다. 합성고분자용액의 퇴화에 대해 시간에 따른 온도와 고분자 농도의 영향을 알아보기 위해 6$0^{\circ}C$, 8$0^{\circ}C$의 온도와 100, 200, 400, 600 ppm의 다양한 고분자 농도에 따라 폐회로방식으로 실험적인 연구를 하였다. 퇴화효과는 기계적 퇴화보다 온도에 더 의존적임이 밝혀졌다. 마찰계수와 레이놀즈 수의 관계는 레이놀즈 수가 5만부터 15만까지의 범위에서 레이놀즈 수가 증가함에 따라 마찰계수가 감소하고, 저온에서 마찰은 Vi가의 최대마찰저항감소 점근선에 접근한다는 것을 보인다. 일정한 유량과 온도에 대해, 높은 고분자 농도에서 퇴화효과가 더 작게 밝혀졌다. 일정한 유량과 고분자 농도에 대해서는 퇴화율이 주로 온도에 영향받는 것으로 밝혀졌다. 8$0^{\circ}C$의 온도, 100 ppm의 고분자 농도에서 4시간후에 마찰저항 감소효과가 없어졌다. 그러나, 열적퇴화는 고분자 분자들간의 결합력을 증가시켜 주는 것으로 생각되는 계면활성제 같은 추가적인 물질을 이용하여 극복할 수 있을 것이다.

Keywords

References

  1. Proc. 1st. Int. Congress on Rheology v.2 Some observations on the flow of linear polymer solutions through straight tubes at large Reynolds numbers Toms, B.A.
  2. J. Hydraulic Res. The ef-fect of drag reduction additives on fluid flows and their industrial application. Part 1: Basic aspects Sellin, R.H.J.;Hoyt, J.W.;Scrivener O.
  3. 14th Int. Conference on Drag Reduction Long-Term Degradation of Dilute Polyacrylamide Solutions in Turbulent Pipe Flow Choi, U.S.;Kasza, K.E.
  4. 14th Int. Conference on Drag Reduction The Critical Shear Stress and Degradation of Polymer Additives in Turbulent Pipe Flow Durst, F.;Schmitt, K.;Brunn, P.O.
  5. 공기조화 · 냉동공학논문집 v.5 no.3 합성고분자첨가제의 난류마찰저항 감소효과 연구 김남수;김종보;김인석;최형진
  6. Trans. ASME, J. Applied Mechanics v.37 The Ul-timate Asymoto and Mean Flow Structure in Tom's Phenomenon Virk, P.S.;Mickley, H.S.;Smith, K.A.
  7. AIChE v.20 Tubulent drag reduction in polymeric solutions containing suspended fibers Lee, W.K.;Vaseleski, R.C.;Metzner, A.B.
  8. AIChE J. v.21 no.4 Drag Reduction Fundamentals Virk, P.S.
  9. AIChE J. v.28 McComb, W.D.;Rabie, L.H.;
  10. Rheol. Acta v.23 Heterogene Widerstandsvermi-derung in Turbulenten Rohrstomungen Bewerdorff, H.W.
  11. J. of Colloid and Interface Science v.53 no.1 The Drag Reduction of Poly(ethylene oxide)-Caboxylate Soap Mixtures Patterson, R.L.;Little, R.C.
  12. Convective Heat Transfer, 2nd Ed. Kays, W.M.;Crawford, M.E.
  13. Advances in Heat Transf-er v.15 Non-Newtonian Fluids in Circular Pipe Flow Cho, Y.I.;Hartnett, J.P.
  14. Chem. Eng. Commun. v.43 Hydraulic Transport of Coal in Pipes with Drag Reducing Additives J. Golda
  15. Prog. Proc. Polym. Sci. v.15 Water Soluble Copolymers XXXII: Macromolecular Drag Reduction, A Review of Predictive Theories and The Effects of Polymer Structure Morgan, S.E.;McCormick, C. L.