DOI QR코드

DOI QR Code

Numerical Simulation of Irregular Airflow in OWC Wave Generation System Considering Sea Water Exchange

해수교환을 고려한 진동수주형 파력발전구조물에서 불규칙공기흐름에 관한 수치해석

  • Lee, Kwang Ho (Maritime & Ocean Engineering Research Institute, KIOST) ;
  • Park, Jung Hyun (Construction of revetment for dredging soil for Song-do at Busan New Port, Hyundai Engineering & Construction Co., Ltd.) ;
  • Cho, Sung (Gyeong water way business division, Korea water resources corporation) ;
  • Kim, Do Sam (Dept. of Civil Eng., Korea Maritime University)
  • 이광호 (한국해양과학기술원 선박해양플랜트연구소 해양플랜트연구부) ;
  • 박정현 (현대건설 부산신항 송도 준설토투기장 호안축조공사현장) ;
  • 조성 (한국수자원공사 경인 아라뱃길건설처) ;
  • 김도삼 (한국해양대학교 건설공학과)
  • Received : 2013.01.14
  • Accepted : 2013.05.27
  • Published : 2013.06.29

Abstract

Due to the global warming and air pollution, interest in renewable energies has increased in recent years. In particular, the crisis of the depletion of fossil energy resources in the near future has accelerated the renewable energy technologies. Among the renewable energy resources, oceans covering almost three-fourths of earth's surface have an enormous amount of energy. For this reason, various approaches have been made to harness the tremendous energy potential. In order to achieve two purposes: to improve harbor water quality and to use wave energy, this study proposed a sea water exchange structure applying an Oscillating Water Column (OWC) wave generation system that utilizes the air flow velocity induced by the vertical motion of water column in the air chamber as a driving force of turbine. In particular, the airflow velocity in the air chamber was estimated from the time variations of water surface profile computed by using 3D-NIT model based on the 3-dimensional irregular numerical wave tank. The relationship of the frequency spectrums between the computed airflow velocities and the incident waves was analyzed. This study also discussed the characteristics of frequency spectrums in the air chamber according to the presence of the structure, wave deformations by the structure, and the power of the water and air flows were also investigated. It is found that the phase difference exists in the time series data of water level fluctuations and air flow in the air chamber and the air flow power is superior to the fluid flow power.

최근, 지구온난화와 대기오염 등에 의해 신재생에너지에 관한 관심이 증가해 왔다. 특히, 가까운 미래에 직면하게 될 화석에너지자원의 고갈문제는 이와 같은 신재생에너지 기술을 가속화 시키고 있다. 다양한 재생가능 에너지자원 중에서 지구의 3/4을 점유하고 있는 해양은 막대한 에너지를 보유하고 있다. 본 연구에서는 항내 수질개선과 파랑에너지의 이용이라는 두 목적을 달성하기 위하여 공기실 내에서 해수면의 상하운동을 공기흐름으로 변환하고, 이를 터빈의 구동력으로 이용하는 파력발전장치인 진동수주형(OWC, Oscillating Water Column) 파력발전시스템을 적용한 해수교환구조물을 제시한다. 또한, 3차원불규칙파수치파동수로에 기초한 3D-NIT(3-Dimensional Numerical Irregular wave Tank)모델을 불규칙파동장에 적용하여 산정된 공기실 내 수위변동의 시간변화로부터 공기흐름속도를 추정하고, 입사주파수스펙트럼의 변화에 따른 공기흐름 주파수스펙트럼의 변화특성, 구조물의 존재여부에 따른 공기실 위치에서 주파수스펙트럼의 변화특성, 구조물에 의한 파랑변형율의 변화특성 및 공기흐름과 유체흐름에 의한 동력 등을 검토한다. 이로부터 공기실 내에서 수위변동 및 공기흐름의 시계열 자료에서 위상차가 존재하며, 유체흐름에 의한 동력이 공기흐름에 의한 동력에 비해 미흡하다는 것을 알 수 있었다.

Keywords

References

  1. 경조현, 홍사영, 홍도천(2006). 진동수주형 파력발전기의 에너지 흡수효율 해석. 한국해양공학회지, 제20권, 제4호, pp.64-69.
  2. 이광호, 박정현, 백동진, 조성, 김도삼(2011). 진동수주형 파력발전구조물의 최적형상에 대한 검토. 한국해안.해양공학회논문집, 제23권, 제5호, pp.345-357.
  3. 이광호, 범성심, 김도삼, 박종배, 안성욱(2012). 공진장치에 의한 단주기파랑의 제어에 관한 연구. 한국해안.해양공학회논문집, 제24권, 제1호, pp.36-47 https://doi.org/10.9765/KSCOE.2012.24.1.036
  4. 이광호, 최현석, 김창훈, 김도삼, 조성(2011). 저반사구조물을 이용한 파력발전에 있어서 압축공기흐름 및 작용파압에 관한 수치해석. 한국해안.해양공학회지, 제23권, 제2호, pp.171-181.
  5. 이민기(2007). CADMAS-SURF에 의한 불규칙파랑의 해석과 월파량추산에 관한 연구, 석사학위논문, 한국해양대학교, pp.38
  6. 조일형(2002). 원통형 진동수주 파력발전구조물에 의한 파 에너지 흡수. 한국해안해양공학회논문집, 제14권, 제1호, pp.8-18.
  7. Boccotti, P.(2007a). Comparison between a U-OWC and a conventional OWC, Ocean Engineering, Vol.34, pp.799-805. https://doi.org/10.1016/j.oceaneng.2006.04.005
  8. Boccotti, P.(2007b). Caisson breakwaters embodying an OWC with a small opening - Part I: Theory. Ocean Engineering, Vol.34, pp.806-819. https://doi.org/10.1016/j.oceaneng.2006.04.006
  9. Bnke, K. and Ambli, N.(1986). Prototype wave power stations in Norway. Proceedings of International Symposium on Utilization of Ocean Waves-Wave to Energy Conversion, ASCE, pp.34-45.
  10. CDIT(2001). Research and Development of Numerical Wave Channel(CADMAS-SURF), CDIT library, No.12, Japan.
  11. Delaure, Y.M.C. and Lewis, A.(2003). 3D hydrodynamic modelling of fixed oscillating water column wave power plant by a boundary element methods. Ocean Engineering, Vol.30, pp.309-330. https://doi.org/10.1016/S0029-8018(02)00032-X
  12. EI Marjani, A., Castro Ruiz, F., Rodriguez, M.A. and Parra Santos, M.T.(2008). Numerical modelling in wave energy conversion systems. Energy, Vol.33, pp.1246-1253. https://doi.org/10.1016/j.energy.2008.02.018
  13. Evans, D.V. and Porter, R.(1995). Hydrodynamic characteristics of an oscillating water column device. Applied Ocean Research, Vol.17, pp.155-164. https://doi.org/10.1016/0141-1187(95)00008-9
  14. Evans, D.V. and Porter, R.(1997). Efficient calculation of hydrodynamic properties of OWC-type devices. J. Offshore Mech. and Article Eng., Vol.119, pp.210-218. https://doi.org/10.1115/1.2829098
  15. Falcao, A.F. de O.(2000). The shoreline OWC wave power plant at the Azores. Proceedings of 4th European Wave Energy Conference, pp.42-47.
  16. Falcao, A.F. de O.(2002). Control of an oscillating-water-column wave power plant for maximum energy production. Applied Ocean Research, Vol.24, pp.73-82. https://doi.org/10.1016/S0141-1187(02)00021-4
  17. Falcao, A.F. de O.(2010). Wave energy utilization: A review of the technologies. Renewable and Sustainable Energy Reviews, Vol.14, pp.899-918. https://doi.org/10.1016/j.rser.2009.11.003
  18. Falcao, A.F. de O. and Justino, P.A.P.(1999). OWC wave energy devices with air flow control. Ocean Engineering, Vol.26, pp.1275-1295. https://doi.org/10.1016/S0029-8018(98)00075-4
  19. Falcao, A.F. de O. and Rodrigues, R.J.A.(2002). Stochastic modelling of OWC wave power plant performance. Applied Ocean Research, Vol.24, pp.59-71. https://doi.org/10.1016/S0141-1187(02)00022-6
  20. Fujiwara, R. (2005). A method for generation irregular waves using CADMAS-SURF and applicability for wave transformation and overtopping, Coastal Eng., JSCE, Vol 52, pp.41-45.
  21. Gervelas, R., Trarieux, F. and Patel, M.(2011). A time-domain simulator for an oscillating water column in irregular waves at model scale. Ocean Engineering, Vol. 38, pp.1-7. https://doi.org/10.1016/j.oceaneng.2010.10.016
  22. Goda, Y. (1985). Random seas and design of maritime structures, University of Tokyo press, pp.323.
  23. Goda, Y. and Suzuki, Y. (1976). Estimation of incident and reflected waves in random wave experiment, Proc. 15th ICCE, ASCE, pp.828-845.
  24. Gouaud, F., Rey, V., Piazzola, J. and Van Hooff, R.(2010). Experimental study of the hydrodynamic performance of an onshore wave power device in the presence of an underwater mound. Coastal Engineering, Vol.57, pp.996-1005. https://doi.org/10.1016/j.coastaleng.2010.06.003
  25. Greenhow, M. and White, S.P.(1997). Optimal heave motion of some axisymmetric wave energy devices in sinusoidal waves. Applied Ocean Research, Vol.19, pp.141-159. https://doi.org/10.1016/S0141-1187(97)00020-5
  26. Heath, T., Whittaker, T.J.T. and Boake, C.B.(2000). The design, construction and operation of the LIMPET wave energy converter(Islay, Scotland). Proceedings of 4th European Wave Energy Conference, pp.49-55.
  27. Hirt. C.W. and Nichols, B.D. (1981). Volume of fluid(VOF) method for the dynamics of free boundaries. J. of Comput. Phys., Vol. 39, pp.201-225. https://doi.org/10.1016/0021-9991(81)90145-5
  28. Josset, C. and Clement, A.H.(2007). A time-domain numerical simulator for oscillating water column wave power plants. Renewable Energy, Vol.32, pp.1379-1402. https://doi.org/10.1016/j.renene.2006.04.016
  29. Malmo, O. and Reitan, A.(1985). Wave-power absorption by an oscillating water column in a channel. J. Fluid Mech., Vol.158, pp.153-175 https://doi.org/10.1017/S0022112085002592
  30. Mitsuyasu, H.(1970). On the growth of spectrum of wind-generated waves(2)-spectral shape of wind waves at finite fetch, Proc. Japanese Conf. on Coastal Eng., JSCE, pp.1-7.
  31. Nakamura, T. and Nakahashi, K.(2005). Effectiveness of a chamber-tpye water exchange breakwater and its ability of wave power extractions by wave induced vortex flows. Proceedings of Civil Engineering in the Ocean, Vol.21, pp.547-552(in Japanese).
  32. Ohneda, H., Igarashi, S., Shinbo, O., Sekihara, S., Suzuki, K. and Kubota, H.(1991). Construction procedure of a wave power extracting caisson breakwater. Proceedings of 3rd Symposium on Ocean Energy Utilization, pp.171-179.
  33. Paixao Conde, J.M. and Gato, L.M.C.(2008). Numerical study of the air-flow in an oscillating water column wave energy converter. Renewable Energy, Vol.33, pp.2637-2644. https://doi.org/10.1016/j.renene.2008.02.028
  34. Ravindran, M. and Koola, P.M.(1991). Energy from sea waves-the Indian wave energy program. Current Science, Vol.60, pp.676-680.
  35. Yin, Z., Shi, H. and Cao, X.(2010). Numerical simulation of water and air flow in oscillating water column air chamber. Proceedings of 20th International Offshore and Polar Engineering Conference, ISOPE, pp.796-801.
  36. 中村孝幸(1999). 透過波の反射波の低減を可能にするカーテン防波堤の構造型式について. 海岸工論文集, 第46卷, pp.786-790.
  37. 中村孝幸, 大村智宏, 大井邦昭 (2003). 渦流制御を利用する海水交換促進型防波堤の效果について. 海岸工學論文集, 第50卷, pp.806-810.

Cited by

  1. Irregular Waves-Induced Seabed Dynamic Responses around Submerged Breakwater vol.28, pp.4, 2016, https://doi.org/10.9765/KSCOE.2016.28.4.177
  2. Regular Waves-induced Seabed Dynamic Responses around Submerged Breakwater vol.28, pp.3, 2016, https://doi.org/10.9765/KSCOE.2016.28.3.132
  3. Numerical Simulation on Seabed-Structure Dynamic Responses due to the Interaction between Waves, Seabed and Coastal Structure vol.26, pp.1, 2014, https://doi.org/10.9765/KSCOE.2014.26.1.49
  4. Numerical Simulation of Dynamic Response of Seabed and Structure due to the Interaction among Seabed, Composite Breakwater and Irregular Waves (II) vol.26, pp.3, 2014, https://doi.org/10.9765/KSCOE.2014.26.3.174
  5. Numerical Simulation of Dynamic Response of Seabed and Structure due to the Interaction among Seabed, Composite Breakwater and Irregular Waves (I) vol.26, pp.3, 2014, https://doi.org/10.9765/KSCOE.2014.26.3.160
  6. Verification of Numerical Analysis Technique of Dynamic Response of Seabed Induced by the Interaction between Seabed and Wave vol.31, pp.1, 2015, https://doi.org/10.7843/kgs.2015.31.1.5
  7. Bore-induced Dynamic Responses of Revetment and Soil Foundation vol.27, pp.1, 2015, https://doi.org/10.9765/KSCOE.2015.27.1.63
  8. Numerical Analysis on Liquefaction Countermeasure of Seabed under Submerged Breakwater using Concrete Mat Cover (for Regular Waves) vol.28, pp.6, 2016, https://doi.org/10.9765/KSCOE.2016.28.6.361
  9. Simulation of Solitary Wave-Induced Dynamic Responses of Soil Foundation Around Vertical Revetment vol.26, pp.6, 2014, https://doi.org/10.9765/KSCOE.2014.26.6.367
  10. 3-Dimensional Numerical Analysis of Air Flow inside OWC Type WEC Equipped with Channel of Seawater Exchange and Wave Characteristics around Its Structure (in Case of Regular Waves) vol.30, pp.6, 2018, https://doi.org/10.9765/KSCOE.2018.30.6.242