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Transient analysis of subcritical/supercritical carbon dioxide based natural circulation loop with end heat exchangers: experimental study

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Abstract

Carbon dioxide (CO2) based natural circulation loops (NCLs) has gained attention due to its compactness with higher heat transfer rate. In the present study, experimental investigations have been carried out to capture the transient behaviour of a CO2 based NCL operating under subcritical as well as supercritical conditions. Water is used as the external fluid in cold and hot heat exchangers. Results are obtained for various inlet temperatures (323–353 K) of water in the hot heat exchanger and a fixed inlet temperature (305 K) of cooling water in the cold heat exchanger. Effect of loop operating pressure (50–90 bar) on system performance is also investigated. Effect of loop tilt in two different planes (XY and YZ) is also studied in terms of transient as well as steady state behaviour of the loop. Results show that the time required to attain steady state decreases as operating pressure of the loop increases. It is also observed that the change in temperature of loop fluid (CO2) across hot or cold heat exchanger decreases as operating pressure increases.

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Abbreviations

c p :

specific heat capacity(J/kgK)

Cu:

Copper

D :

internal diameter of inner pipe or loop diameter (m)

d o :

external diameter of inner pipe or loop diameter (m)

g :

gravitational acceleration (m/s2)

H 0 :

total height of vertical pipe (m)

L :

length of CHX (sink) and HHX (source) (m)

L 0 :

total length of a horizontal pipe (m)

L 1 :

adiabatic pipe length on horizontal pipe (m)

m :

mass flow rate (kg/s)

Q :

heat transfer rate (W)

\(q^{{{\prime \prime }}}\) :

heat flux (W/m2)

R :

Radius of curvature for bends (m)

SS:

Stainless steel

T :

temperature (K)

t :

time (s)

∆T :

loop fluid temperature difference between riser and downcomer centres (K)

∆T w :

temperature rise/drop of water across the CHX or HHX (K)

CHX :

cold heat exchanger, sink

CO 2 :

carbon dioxide

HHX :

hot heat exchanger, source

w :

water

References

  1. Pearson A (2005) Carbon dioxide—new uses for old refrigerant. Int J Refrig 28:1140–1148

    Article  Google Scholar 

  2. Kumar KK, Ramgopal M (2009) Carbon dioxide as secondary fluid in natural circulation loops. Proc IMechE, Part E: J Process Mech Eng 223:189–194

    Google Scholar 

  3. Yadav AK, Ramgopal M, Bhattacharyya S (2012) CO2 based natural circulation loops: new correlations for friction and heat transfer. Int J Heat Mass Transf 55:4621–4630

    Article  Google Scholar 

  4. Dostal V, Hejzlar P, Driscoll MJ (2006) The supercritical carbon dioxide power cycle: comparison to other advanced power cycles. Nucl Technol 154:283–301

    Article  Google Scholar 

  5. Bondioli P, Mariani C, Mossa E, Fedelli A, Muller A (1992) Lampante olive oil refining with supercritical carbon dioxide. J Am Oil Chem Soc 69:477–480

    Article  Google Scholar 

  6. Fourie FCVN, Schwarz CE, Knoetze JH (2008) Phase equilibria of alcohols in supercritical fluids Part I. The effect of the position of the hydroxyl group for linear C8 alcohols in supercritical carbon dioxide. J Supercrit Fluids 47:161–167

    Article  Google Scholar 

  7. Yamaguchi H, Zhang XR, Fujima K (2008) Basic study on new cryogenic refrigeration using CO2 solid–gas two phase flow. Int J Refrig 31:404–410

    Article  Google Scholar 

  8. Ochsner K (2008) Carbon dioxide heat pipe in conjunction with a ground source heat pump (GSHP). Appl Therm Eng 28:2077–2082

    Article  Google Scholar 

  9. Kim DE, Kim MH, Cha JE, Kim SO (2008) Numerical investigation on thermal–hydraulic performance of new printed circuit heat exchanger model. Nucl Eng Des 238:3269–3276

    Article  Google Scholar 

  10. Kreitlow DB, Reistad GM (1978) Themosyphon models for down hole heat exchanger application in shallow geothermal systems. J Heat Transf 100:713–719

    Article  Google Scholar 

  11. Torrance KE (1979) Open-loop thermosyphons with geological application. J Heat Transf 100:677–683

    Article  Google Scholar 

  12. Chen L, Zhang X (2014) Experimental analysis on a novel solar collector system achieved by supercritical CO2 natural convection. Energy Convers Manag 77:173–182

    Article  MathSciNet  Google Scholar 

  13. Yanagisawa Y, Fukuta M, Ogura N, Kaneo H, Operating characteristics of natural circulating CO2 secondary loop refrigeration system working with NH3 primary loop. In: Proceedings of the 6th IIR-Gustav Lorentzen Natural Working Fluids Conference, 2004

  14. Kiran Kumar K, Ramgopal M (2011) Experimental studies on CO2 based single and two-phase natural circulation loops. Appl Therm Eng 31:3437–3443

    Article  Google Scholar 

  15. Chen L, Deng BL, Zhang XR (2013) Experimental investigation of CO2 thermosyphon flow and heat transfer in the supercritical region. Int J Heat Mass Transf 64:202–211

    Article  Google Scholar 

  16. Sharma M, Vijayan PK, Pilkhwal DS, Asako Y (2013) Steady state and stability characteristics of natural circulation loops operating with carbon dioxide at supercritical pressures for open and closed loop boundary conditions. Nucl Eng Des 265:737–754

    Article  Google Scholar 

  17. Liu G, Huang Y, Wang J, Lv F, Leung LHK (2016) Experiments on the basic behavior of supercritical CO2 natural circulation. Nucl Eng Des 300:376–383

    Article  Google Scholar 

  18. Liu G, Huang Y, Wang J, Leung LHK (2016) Heat transfer of supercritical carbon dioxide flowing in a rectangular circulation loop. Appl Therm Eng 98:39–48

    Article  Google Scholar 

  19. Archana V, Vaidya AM, Vijayan PK (2015) Flow transients in supercritical CO2 natural circulation loop. Proc Eng 127:1189–1196

    Article  Google Scholar 

  20. Swapnalee BT, Vijayan PK, Sharma M, Pilkhwal DS (2012) Steady state flow and static instability of supercritical natural circulation loops. Nucl Eng Des 245:99–112

    Article  Google Scholar 

  21. Kiran Kumar K, Ramgopal M (2009) Steady-state analysis of CO2 based natural circulation loops with end heat exchangers. Appl Therm Eng 29:1893–1903

    Article  Google Scholar 

  22. Yadav AK, Ramgopal M, Bhattacharyya S (2014) Transient analysis of subcritical/supercritical carbon dioxide based natural circulation loops with end heat exchangers: numerical studies. Int J Heat Mass Transf 79:24–33

    Article  Google Scholar 

  23. Yadav AK, Ramgopal M, Bhattacharyya S (2016) Effect of tilt angle on subcritical/supercritical carbon dioxide based natural circulation loop with isothermal source and sink. ASME J Therm Sci Eng Appl 8:011007-1–011007-8

    Google Scholar 

  24. Sabersky RH, Hauptmann EG (1967) Forced convection heat transfer to carbon dioxide near the critical point. Int J Heat Mass Transf 10:1499–1508

    Article  Google Scholar 

  25. Yadav AK, Bhattacharyya S, Ramgopal M (2016) Optimum operating conditions for subcritical/supercritical fluid based natural circulation loops. ASME J Heat Transf 138:112501-1–112501-9

    Google Scholar 

  26. He S, Kim WS, Jackson JD (2008) A computational study of convective heat transfer to carbon dioxide at a pressure just above the critical value. Appl Therm Eng 28:1662–1675

    Article  Google Scholar 

  27. Yadav AK, Ramgopal M, Bhattacharyya S (2012) CFD analysis of a CO2 based natural circulation loop with end heat exchangers. Appl Therm Eng 36:288–295

    Article  Google Scholar 

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Acknowledgment

The study has been carried out under a project sponsored by Extramural Research Division, Council of Scientific and Industrial Research (CSIR), Government of India. The financial support provided by CSIR is gratefully acknowledged.

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Authors and Affiliations

  1. Department of Mechanical Engineering, National Institute of Technology Karnataka, Surathkal, 575025, India

    Ajay Kumar Yadav

  2. Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, WB, 721302, India

    Maddali Ramgopal & Souvik Bhattacharyya

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  1. Ajay Kumar Yadav
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  2. Maddali Ramgopal
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  3. Souvik Bhattacharyya
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Correspondence to Ajay Kumar Yadav.

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Yadav, A.K., Ramgopal, M. & Bhattacharyya, S. Transient analysis of subcritical/supercritical carbon dioxide based natural circulation loop with end heat exchangers: experimental study. Heat Mass Transfer 53, 2951–2960 (2017). https://doi.org/10.1007/s00231-017-2038-z

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  • DOI: https://doi.org/10.1007/s00231-017-2038-z

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