Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
권호 표지
DOI QR코드

DOI QR Code

Thermal-hydraulic simulation and evaluation of a natural circulation thermosyphon loop for a reactor cavity cooling system of a high-temperature reactor

  • Swart, R. (Stellenbosch University, Mechanical Engineering Department) ;
  • Dobson, R.T. (Stellenbosch University, Mechanical Engineering Department)
  • Received : 2019.02.21
  • Accepted : 2019.07.29
  • Published : 2020.02.25
Download PDF
⟨ Previous Next ⟩

Abstract

The investigation into a full-scale 27 m high, by 6 m wide, thermosyphon loop. The simulation model is based on a one-dimensional axially-symmetrical control volume approach, where the loop is divided into a series of discreet control volumes. The three conservation equations, namely, mass, momentum and energy, were applied to these control volumes and solved with an explicit numerical method. The flow is assumed to be quasi-static, implying that the mass-flow rate changes over time. However, at any instant in time the mass-flow rate is constant around the loop. The boussinesq approximation was invoked, and a reasonable correlation between the experimental and theoretical results was obtained. Experimental results are presented and the flow regimes of the working fluid inside the loop identified. The results indicate that a series of such thermosyphon loops can be used as a cavity cooling system and that the one-dimensional theoretical model can predict the internal temperature and mass-flow rate of the thermosyphon loop.

Keywords

References

  1. R. Dobson, J. Ruppersberg, Flow and heat transfer in a closed loop thermosyphon. Part Ietheoretical simulation, J. Energy South. Afr. 18 (2007) 41-48.
  2. J.C. Ruppersberg, R.T. Dobson, Flow and heat transfer in a closed loop thermosyphon Part II-experimental simulation, J. Energy South. Afr. 18 (2007) 41-48.
  3. Y. Cao, M. Gao, Wickless network heat pipes for high heat flux spreading applications, Int. J. Heat Mass Transf. 45 (2002) 2539-2547. https://doi.org/10.1016/S0017-9310(01)00338-6
  4. A.S. Sundaram, A. Bhaskaran, Thermal modeling of thermosyphon integrated heat sink for CPU cooling, J. Electron. Cool. Therm. Control 01 (2011) 15-21.
  5. H. Bielinski, Validation of the generalized model of two-phase thermosyphon loop based on experimental measurements of volumetric flow rate, Arch. Therm. 37 (2016) 109-138. https://doi.org/10.1515/aoter-2016-0023
  6. C.C.J. Vincent, J.B.W. Kok, Investigation of the overall transient performance of the industrial two-phase closed loop thermosyphon, Int. J. Heat Mass Transf. 35 (1992) 1419-1426. https://doi.org/10.1016/0017-9310(92)90033-O
  7. S.L. Abreu, S. Colle, An experimental study of two-phase closed thermosyphons for compact solar domestic hot-water systems, Sol. Energy 76 (2004) 141-145. https://doi.org/10.1016/j.solener.2003.02.001
  8. T. Yilmaz, Computer Simulation of Two-phase Flow Thermosyphon Solar Water Heating System, vol. 32, 1991, pp. 133-144. https://doi.org/10.1016/0196-8904(91)90153-A
  9. J. Venkata, P. Bhramara, ScienceDirect CFD analysis of multi turn pulsating heat pipe, Mater. Today Proc. 4 (2017) 2701-2710.
  10. R.T. Dobson, A novel closed loop thermosyphon heat pipe reactor cavity cooling system for a pebble bed modular reactor, in: 8th Int. Heat Pipe Symp, Kumamoto, 2006, 397-384.
  11. S.Y. Lee, Y.L. Kim, An analytical investigation of role of expansion tank in semiclosed two-phase natural circulation loop, Nucl. Eng. Des. 190 (1999) 353-360. https://doi.org/10.1016/S0029-5493(99)00079-5
  12. V.P. Carey, Liquid-Vapor Phase-Change Phenomena, First Eddi, Hemisphere Publiching Corporation, Bristol, 1992.
  13. P.B. Whalley, Boiling Condensation and Gas-Liquid Flow, First eddi, Oxford Unifersity Press, New York, 1897.
  14. J.A. Boure, A.E. Bergles, L.S. Tong, Review of two-phase flow instability, Nucl. Eng. Des. 25 (1973) 165-192. https://doi.org/10.1016/0029-5493(73)90043-5
  15. A. Mills, V. Ganesan, Heat Transfer, Pearson, 2015.
  16. R. Yang, R. Liu, Y. Zhong, T. Liu, Experimental study on convective heat transfer of water flow in a heated tube under natural circulation, Nucl. Eng. Des. 236 (2006) 1902-1908. https://doi.org/10.1016/j.nucengdes.2006.01.013
  17. J.C. Chen, Correlation for boiling heat transfer to saturated fluids in convective flow, Ind. Eng. Chem. Process Des. Dev. 5 (1966) 322-329. https://doi.org/10.1021/i260019a023
  18. D.P. Traviss, W.M. Rohsenow, A.B. Baron, Forced-convection condensation inside tubes: a heat transfer equation for condenser design, ASHRAE Transact. 79 (1973) 157-165.
  19. Y.A. Cengel, A.J. Ghajar, Heat and Mass Transfer, MC Graw Hill, Fifth, 2012.
  20. R. Swart, Theoretical and Experimental Evaluation of a High Temperature Reactor (HTR) Cavity Cooling System (RCCS), Meng (Research), University of Stellenbosch. Stellenbosch South Africa, 2018.

Cited by

  1. Natural circulation pump with asymmetrical heat transfer wall as the element of Büttiker-Landauer thermal ratchet vol.32, pp.11, 2020, https://doi.org/10.1063/5.0032542