Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887

access icon free Controlling the thermal environment of underground cable lines using the pavement surface radiation properties

© The Institution of Engineering and Technology
Received 23/08/2017, Accepted 29/03/2018, Revised 02/03/2018, Published 04/04/2018

The main purpose of this study is to show how the emissivity and absorptivity of a pavement surface above underground cables affect their ampacity. The use of cool pavements whose surfaces absorb less heat from the Sun than they emit to the ambient is considered as a novel method to control the thermal environment of underground cables. The method predicts that the trench along the entire length of a 110 kV cable line is completely filled with quartz sand and paved with a cool pavement. Quartz sand would provide good conduction of heat from the cables to the earth and pavement surfaces, while a paved surface of the trench would establish approximately unchangeable convection and radiation boundary conditions along the entire cable line route. It is assumed that the three-phase system is balanced and that the boundary conditions along the earth and pavement surfaces are the most unfavourable. The novel method is based on the results of experimental research, generalised and verified numerically using the finite-element method in COMSOL. Finally, it is established that the ampacity of the 110 kV cable line can be increased up to 26.7%.

Inspec keywords: heat conduction; underground cables; power cables; temperature control; convection

Other keywords: underground cable lines; voltage 110 kV; convection; heat conduction; thermal environment control; radiation boundary conditions; cool pavements; COMSOL; pavement surface absorptivity; pavement surface radiation properties; pavement surface emissivity; three-phase system; quartz sand

Subjects: Power cables; Thermal variables control; Control of electric power systems

References

    1. 1)
      • 7. International Standard IEC 60287–1-1:2006+AMD1:2014 CSV: ‘Electric cables – calculation of the current rating – part 1-1: current rating (100% load factor) and calculation of losses – General’ (International Electrotechnical Commission, Switzerland, 2014, 2.1 edn.).
    2. 2)
      • 14. Herb, W.R., Janke, B., Mohseni, O., et al: ‘All-weather ground surface temperature simulation’. Project Report No. 478, St. Anthony Falls Laboratory, University of Minnesota, September 2006.
    3. 3)
      • 9. Çengel, Y.A.: ‘Introduction to thermodynamics and heat transfer’ (The McGraw-Hill Companies Inc., USA, 2008, 2nd edn.).
    4. 4)
      • 15. Gouda, O.E., Amer, G.M., El Dein, A.Z.: ‘Effect of dry zone formation around underground power cables on their ratings’. 20th Int. Conf. Electricity Distribution, Session 1, Paper 0120, Prague, Czech Republic, June 2009.
    5. 5)
      • 5. Rerak, M., Ocłoń, P.: ‘The effect of soil and cable backfill thermal conductivity on the temperature distribution in underground cable system’. 2017, vol. 13, Article No. 02004, E3S Web Conf., 4th Scientific and Technical Conference on Modern Technologies and Energy Systems, WTiUE, Cracow, Poland, October 2016, pp. 1–6, doi: 10.1051/e3sconf/20171302004.
    6. 6)
      • 1. Al-Saud, M.S., El-Kady, M.A., Findlay, R.D.: ‘A new approach to underground cable performance assessment’, Electr. Power Syst. Res., 2008, 78, (5), pp. 907–918.
    7. 7)
      • 8. COMSOL: ‘Heat transfer module user's guide’, Version 4.3, May 2012.
    8. 8)
      • 2. Nahman, J., Tanaskovic, M.: ‘Calculation of the ampacity of high voltage cables by accounting for radiation and solar heating effects using FEM’, Int. Trans. Electr. Energy Syst., 2013, 23, (3), pp. 301–314.
    9. 9)
      • 16. Gouda, O.E., El Dein, A.Z., Amer, G.M.: ‘Effect of the formation of the dry zone around underground power cables on their ratings’, IEEE Trans. Power Deliv., 2011, 26, (2), pp. 972–978.
    10. 10)
      • 3. Klimenta, D., Nikolajević, S., Sredojević, M.: ‘Controlling the thermal environment in hot spots of buried power cables’, Eur. Trans. Electr. Power, 2007, 17, (5), pp. 427–449.
    11. 11)
      • 13. Smith, J.O.: ‘Determination of the convective heat transfer coefficients from the surfaces of buildings within urban street canyons’. PhD thesis, University of Bath, 2010.
    12. 12)
      • 4. Dubitsky, S., Greshnyakov, G., Korovkin, N.: ‘Multiphysics finite element analysis of underground power cable ampacity’. Proc. 2014 Int. Conf. Energy, Environment and Material Science (EEMAS ‘14), Saint Petersburg, Russia, 23–25 September 2014, pp. 84–89.
    13. 13)
      • 11. Seemann, S.W., Borbas, E.E., Knuteson, R.O., et al: ‘Development of a global infrared land surface emissivity database for application to clear sky sounding retrievals from multispectral satellite radiance measurements’, J. Appl. Meteorol. Climatol., 2008, 47, pp. 108–123.
    14. 14)
      • 10. Andersland, O.B., Ladanyi, B.: ‘Frozen ground engineering’ (John Wiley & Sons, Hoboken, NJ, USA, 2003, 2nd edn.).
    15. 15)
      • 6. Klimenta, D., Perovic, B., Jevtic, M., et al: ‘A thermal FEM-based procedure for the design of energy-efficient underground cable lines’, Humanities Sci. Univ. J. Technics, 2014, 10, pp. 162–188.
    16. 16)
      • 12. Tan, S.-A., Fwa, T.-F.: ‘Influence of pavement materials on the thermal environment of outdoor spaces’, Build. Environ., 1992, 27, (3), pp. 289–295.
http://iet.metastore.ingenta.com/content/journals/10.1049/iet-gtd.2017.1298
Loading

Related content

content/journals/10.1049/iet-gtd.2017.1298
pub_keyword,iet_inspecKeyword,pub_concept
6
6
Loading
Print this page
This is a required field
Please enter a valid email address