Skip to main content
SpringerLink
Log in

Development study of automatic control system for the demonstration plant of ocean thermal energy conversion (OTEC) using sequence controller

Journal of Marine Science and Technology volume 27, pages 759–771 (2022)Cite this article

Abstract

Based on the success of the demonstration experiment of MW-class Ocean Thermal Energy Conversion (OTEC) in East Sea, Korea, OTEC technology is expected to spread in the future. In order for this to happen, technology improvement factors, such as minimizing human error and reducing operating costs through automatic start and stop for stable operation, are to be applied. In this paper, the operation performance of a 20 kW-class pilot model for the automated start and stop of the recently demonstrated MW-class OTEC served as the basis for the scenario. The scenario derived from the operation experiment of the 20 kW-class pilot plant established the starting conditions of the surface water and deep water seawater inflow conditions with maximum flow conditions of 1,864 kg/s and 1,507 kg/s, respectively, at the initial start-up of the MW-class OTEC. The refrigerant circulation pump produces 86.4 kW initial power at 700 RPM (Max 1,150) when the turbine bypass valve is closed by 50%. The maximum flow condition of 104.0 kg/s through the sequential increase in refrigerant flow and decrease in the opening of the turbine bypass valve generated an output of 886.9 kW. In the stop condition, the RPM of the refrigerant pump is reduced to 800, and the bypass valve is fully closed. Moreover, the power generation output is reduced to 154.3 kW. In accordance with the normal stop condition of 200 kW or less, the bypass valve, which is fully opened, and the valve at the turbine inlet, which is completely opened and closed, block the inflow into the turbine. On the other hand, the opening degree of the bypass valve, which is fully opened, reduces the turbine output to 0 kW in the emergency stop condition. Then, the turbine inlet valve, which is completely opened and closed, blocks the working fluid inflow. As the bypass valve opens abruptly, the flow rate of the working fluid increases up to 328.0 kg/s due to the decrease in turbine resistance. In doing so, the flow rate decreases, and the working fluid amount in the liquid separator decreases. The construction of an automated system for the empirical model in the future will use the OTEC start and stop simulation results derived through this study.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

References

  1. EIA (2016) International energy outlook 2016

  2. IEA-OES (2007) International energy agency implementing agreement on ocean energy systems. In: Proceedings of the ASME 2007 26th international conference on offshore mechanics and arctic engineering, San Diego, CA, USA, 10–15 June 2007, pp 609–613

  3. Vega LA (2012) Ocean thermal energy conversion. Springer, Encyclopedia of sustainability science and technology, pp 7296–7328

    Google Scholar 

  4. Chul Oh (2011) Current status and future prospects of heating and cooling systems and power generation systems using ocean temperature difference. Mag SAREK 40(8):29–39

    Google Scholar 

  5. Meyer L, Cooper D, Varley R (2013) Are we there yet? A developer's roadmap to otec commercialization (PDF). Hawaii National Marine Renewable Energy Center. Retrieved 28 March 2013

  6. Harun R, Ja’afar S (2021) Malaysia: a maritime nation (hard cover). Maritime Institute of Malaysi, Kuala Lumpur

    Google Scholar 

  7. Lee H Lee S, Kim H, Jung Y (2015) Performance characteristics of 20 kW ocean thermal energy conversion pilot plant. In: Proceedings of the ASME 2015 9th international conference on energy sustainability collocated with the ASME 2015 power conference, the ASME 2015 13th international conference on fuel cell science, engineering and technology, and the ASME 2015 nuclear forum: volume 1. San Diego, California, USA. June 28–July 2, 2015. V001T07A002. ASME. https://doi.org/10.1115/ES2015-49768

  8. Seungtaek L, Hosaeng L, Junghyun M, Hyeonju K (2020) Simulation data of regional economic analysis of otec for applicable area. Processes 8(9):1107. https://doi.org/10.3390/pr8091107

    Article  Google Scholar 

  9. Lee H, Lim S, Yoon J, Kim H (2020). Novel OTEC cycle using efficiency enhancer, ocean thermal energy conversion (OTEC)—past, present, and progress. In: Kim AS, Kim H-J (eds) IntechOpen. https://doi.org/10.5772/intechopen.90791. Available from: https://www.intechopen.com/books/ocean-thermal-energy-conversion-otec-past-present-and-progress/novel-otec-cycle-using-efficiency-enhancer

  10. Kim H-J, Lee H-S, Lim S-T, Petterson M (2021) The suitability of the pacific islands for harnessing ocean thermal energy and the feasibility of OTEC plants for onshore or offshore processing. Geosciences 11:407. https://doi.org/10.3390/geosciences11100407

    Article  Google Scholar 

  11. Moon J-H, Lee H-S, Lim S-T, Seo J-B, Kim H-J (2020) Plant performance evaluation experiment to expand the applicability of ocean thermal energy conversion. J Power Syst Eng 24(5):78–85. https://doi.org/10.9726/kspse.2020.24.5.078

    Article  Google Scholar 

  12. Oh JT, Hihara E (2000) Condensation heat transfer for pure HFC refrigerants and a ternary refrigerants mixture inside a horizontal tube. Korean Soc Mech Eng 24(2):233–240

    Google Scholar 

  13. Aspen HYSYS (2011) Dynamic modeling guide. Aspen Technology Inc, Bedford

    Google Scholar 

  14. Vega LA, Michaelis D (2010) First generation 50 MW OTEC plantship for the production of electricity and desalinated. In: Proceeding of offshore technology conference (OTC 20957). Offshore technology conference, Texas, pp 1–17

  15. Coastal Response Research Center (2010) Ocean thermal energy conversion: assessing potential physical, chemical and biological impacts and risks. University of New Hampshire, Durham, NH, 39 pp and appendices

  16. Anderson PM, Fouad AA (2002) Power system control and stability. Wiley, New York

    Book  Google Scholar 

  17. Matsuda Y, Goto S, Sugi T, Morisaki T, Yasunaga T, Ikegami Y (2017) Control of OTEC plant using double-stage Rankine cycle considering warm seawater temperature variation. IFAC PapersOnLine 50(1):135–140

    Article  Google Scholar 

  18. Avery WH, Wu C (1994) Renewable energy from the ocean: a guide to OTEC. Oxford University Press, Oxford

    Book  Google Scholar 

  19. Galbraith (2009) Generating energy from the deep. New York Times

  20. Uehara H, Nakaoka T (2005) Development and prospective of ocean thermal energy conversion and spray flash evaporator desalination. Saga University, Saga, Japan. Viewed on December 3, 2007. http://www.ioes.saga-u.ac.jp/VWF/general-review_e.html#8

  21. Hsu C-Y, Chen M-W, Huang P-H (2017) Dynamic response analysis of micro-grid with ocean thermal energy conversion. J Mar Sci Technol 25(6):775–783. https://doi.org/10.6119/JMST-017-1226-19

    Article  Google Scholar 

  22. Goto S, Iseri D, Matsuda Y, Sugi T, Morisaki T, Ikegami Y (2012) Simulation model od evaporator and separator in OTEC plant using Uehara cycle for liquid level control. In: Proceedings of SICE annual conference 2012, Akita, Japan, pp 2088–2093

  23. Matsuda Y, Shimada T, Sugi T, Goto S, Morisaki T, Ikegami Y (2015) Controller design for liquid level control of separator in an OTEC plant with Uehara cycle considering disturbances. In: Proceeding of 15th international conference on control, automation and systems (ICCAS), pp 12–15

  24. Seungtaek L, Hoseang L, Hyeonju K (2020) Dynamic simulation of system performance change by PID automatic control of ocean thermal energy conversion. J Mar Sci Eng 8(1):59. https://doi.org/10.3390/jmse8010059

    Article  Google Scholar 

  25. Wang L, Huang C (2010) Dynamic stability analysis of a grid-connected solar-concentrated ocean thermal energy conversion system. IEEE Trans Sustain Energy 1(1):10–18. https://doi.org/10.1109/TSTE.2010.2046189

    Article  Google Scholar 

Download references

Acknowledgements

This research was financially supported by the grant from the National R&D project of “Development of 1 MW Ocean Thermal Energy Conversion Plant for Demonstration” funded by the Ministry of Oceans and Fisheries, Korea (PMS4730).

Author information

Authors and Affiliations

  1. Seawater Utilization Plant Research Center, Korea Research Institute of Ships and Ocean Engineering, Daejeon, 34103, Korea

    Seungtaek Lim, Hoseang Lee & Hyeonju Kim

Authors
  1. Seungtaek Lim
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Hoseang Lee
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hyeonju Kim
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Hyeonju Kim.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lim, S., Lee, H. & Kim, H. Development study of automatic control system for the demonstration plant of ocean thermal energy conversion (OTEC) using sequence controller. J Mar Sci Technol 27, 759–771 (2022). https://doi.org/10.1007/s00773-021-00869-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00773-021-00869-z

Keywords

search

Navigation