Heat Transfer to Liquid Sodium in the Thermal Entrance Region
Total Page:16
File Type:pdf, Size:1020Kb
UNIVERSITE LIBRE DE BRUXELLES FACULTE DES SCIENCES APPLIQUEES CENTRE O'ETUDE DE L'ENERGIE NUCLEAIRE STUDIECENTRUM VOOR KERNENERGIE HEAT TRANSFER TO LIQUID SODIUM IN THE THERMAL ENTRANCE REGION UN, RMSII Mai 1101 Dlsstrtatfei artstatta •• wit dt J'titiHIti rfi iratft tft . •tctiar M SclMCtt ApMltjMtt. UNIVERSITE LIBRE DE BRUXELLES FACULTE DES SCIENCES APPLIQUEES Institut de Mécanique Service de Métrologie Appliquée Nucléaire CENTRE D'ETUDE DE L'ENERGIE NUCLEAIRE STUDIECENTRUM VOOR KERNENERGIE Département Technologie h Energie HEAT TRANSFER TO LIQUID SODIUM IN THE THERMAL ENTRANCE REGION QIU, Reuse» Mai 1981 Dissertation présentée ei vie de l'obtention da trade de Docteur en Sciences Appliques. , >* Le travail, obget de oe mimoire, a 6ti effectuS aous la direction de la Faculti dee Saienaea Appliquiea de I'VniveraitS Libre de Bruxelle8 et r&alis6 au department Technologic et Energie du Centre d'Etude de I'Energie NucUaire d MDL. Je tiena d remeroier vivement lea direeteur8 Messieurs les Professsurs A. JAUMOTTE et J. DEVCOGET pour lea suggestions utilea, lea discussions fructueuaea et lea encouragements incessants. ties remerciement8 vont 4galement & Monsieur J. PLANQUART, Chef du d&gartewenty pour le support effioaae et lea enoouragementa prodiguis tout au long de won travail. Toute ma reaormaiaaanae A Meaeieura G. VAXMASSEHHOVE, J. DEKEYSER et B. ARIEN ainei qu'd. toue ceux du d&partement qui ont3 par leur travail et leur aoutien3 contribuer & la realisation du montage, & la pourauite des essais et a la dactylographie du document. GrSae a la collaboration de toua3 j'ai pu terminer ce travail dans lea dilaia courts qui m'Staient fia&a, notamsnt du fait de la durie limitie de mm sijour en Belgique. QIU, Beneen. CONTENTS List of Figures Nomenclature I Introduction ' II Literature Review 4 2.1. Theoretical Studies 5 2.2. Experimental Studies 28 III General Investigation about Heat Transfer in the Thermal 41 Entrance Region 3.1. Characteristics of Liquid Sodium 42 3.2. Behaviors in the Thermal Entrance Region 44 3.3. Thermal Entrance Length 50 3.4. Influence of Reynolds Number on Heat Transfer in the 53 Thermal Entrance Region 3.5. Influence of Prandtl Number on Heat Transfer in the 60 Thermal Entrance Region 3.6. Influence of Velocity Development on tfeat Transfer in 66 the Thermal Entrance Region 3.7. Hydrodynamic Entrance Length 70 3.8. Effect of Axial Conduction 71 3.9. Natural Convection Effect on Heat Transfer in the 79 Thermal Entrance Region 3.10. Influence of Radius Ratio 86 3.11. Influence of Circumferential Variation of Heat Flux on 87 Heat Transfer in the Thermal Entrance Region 3.12. Effects of Wetting, Oxide Film and Gas Entrainment 89 Document typed and printed at CEN/SCR - MOL. II IV Theoretical Analysis of Turbulent Heat Transfer to Liquid 95 Sodium in the Thermal Entrance Region 4.1. Turbulent Energy Equation 96 4.2. Turbulent Heat Transfer to Liquid Solium in the Thermal 10] Entrance Regions of Annulus and Rod Bundles 4.3. Velocity Profiles in the Annular Channel 127 4.4. Eddy Diffusivities 140 4.5. Ratio of the Eddy Diffusivity for Heat Transfer to the 148 Eddy Diffusivity for Momentum Transfer 4.6. Radius of Maximum Local Velocity Point 150 4.7. Friction Velocity 154 4.8. Analytical Results of Heat Transfer in the Thermal 158 Entrance Region of Annulus 4.9. Turbulent Heat Transfer in the Thermal Entrance Region 162 of Circular Tube 4.10. Turbulent Heat Transfer in the Thermal Entrance Region 165 of Parallel-Plate Channel 4.11. Heat Transfer in Annulus and Rod Bundles with Variable |69 Heat Flux 4.12. Asymptotic Solution for the Initial Portion of Thermal 173 Entrance Region 4.13. Comparison with the Results Neglecting Thermal Developing 181 Effect 4.14. Time-Dependent Temperature Evolution 186 Ill Experimental Investigation of Turbulent Heat Transfer to Liquid 191 Sodium in the Thermal Entrance Region of Annulus 5.1. Purposes of Experiments 192 5.2. Related Characteristics of the Core of Fast Reactor 192 5.3. Definition of Experimental Conditions 193 5.3.1. Definition of the diameters of channel 5.3.2. Definition of the heating element length 5.3.3. Definition of the length of the section for stabilization of flow 5.3.4. Definition of the inlet teaperature of the test section 5.3.5. Definition of the flowrate in the test section 5.4. Description of the Experimental System 196 5.4.1. Description of sodium loop 5.4.2. Description of test section 5.4.3. Measurement system 5.5. Preliminary Experiments 210 5.5.1. Purposes of preliminary experiments 5.5.2. Verification of the readings of thermocouples 5.5.3. Determination of heat less 5.5.4. Determination of stabilization time 5.6. Procedure of Main Experiments 212 5.7. Data Reduction 213 5.7.1. Bulk temperature 5.7.2. Wall temperature 5.7.3. Heat loss 5.7.4. Leak flowrate 5.7.5. Parameters representing the results 5.7.6. Estimation of teaperature measurement errors produced by the lead wires of thermocouples 5.7.7. Correction for the influence of thermocouple station 5.8. Time-dependent Temperature Evolution in the Channel of Liquid 229 Sodium 5.8.1. Experimental apparatus 5.8.2. Experimental procedures IV 5.9. Results of Experiments. 232 5.9.1. Results of the main experiments 5.9.2. Results of the time-dependent temperature experiments 5.10. Error Analysis 236 VI. Discussion and Conclusions. 239 6.1. Comparison of Theoretical and Experimental Results 240 6.2. Comparison of Fully Developed Values of the Nusselt Number 240 6.3. Conclusions. 241 BIBLIOGRAPHY 243 APPENDIX 262 FIGURES 268 LIST OF FIGURES 3.1.-1 Fully developed temperature distribution during turbulent heat transfer 3.2.-1 Boundary layer growth 3.2.-2 Coordinates for parallel-plate channel 3.3.-1 Variation of thermal entrance lengths 3.4.-1 Effect of Reynolds number (for Pr=0.006) 3.4.-2 Effect of Prandtl number (for Re=5xlO4, Y2/Yi=2) 3.4.-3 Effect of Reynolds number (for Pr=0.006, "Y2/Yx=2) 3.4.-4 Effect of Reynolds number (for Pr=0.74, y2/ j=2) 3.5.-1 Effect of Prandtl number for pipe (for Re=104) 3.5.-2 Effect of Prandtl number for parallel plates (for Re=104) 3.5.-3 Effect of Prandtl number (for Re=5xlO4, Y2/Vi=2) 3.5.-4 Variation of thermal entrance length 3.6.-1 Effect of velocity development 3.8.-1 Effect of axial conduction (for various Pe) 3.8.-2 Effect of axial conduction (for various Re) 3.8.-3 Effect of axial conduction (for various Pr) 3.9.-1 Effect of natural convection 4.2.-1 Annular cell 4.2.-2 Annular channel 4.2.-3 Differential element for energy balance 4.3.-1 Shear stress nomenclature 4.3.-2 Variation of heat flux 4.3.-3 Comparison of results with difterent velocity profiles 4.5.-1 Comparison of results with different values I|I = 4.8.-1 Effect of Reynolds number (for Pr=0.0054t Y2/Yi 2) 4.8.-2 Effect of Reynolds number (for Pr=0.0054, Y2/Yi=2) 4.8.-3 Effect of Reynolds number (for Pr=0.0054, Y2»Yi=2) 4.8.-4 Temperature profiles (for Re=6.000, Y2/"Yi=2) 4.8.-5 Temperature profiles (for Re=8.000, Y2/Yi=2) 4.8.-6 Temperature profiles (for Re=2xlO4, Y2/Yi=2) 4.8.-7 Temperature profiles (for Re=4xlO4, Y2/Vi=2) 4.8.-8 Temperature profiles (for Re=6xlO4, Y2/Yi=2) 4 4.8.-9 Temperature profiles (for Re=8xlO , Y2/Yi=2) 4.8.-10 Temperature profiles (for Re=105, Y2/Yi=2) 4.8.-11 Temperature profiles (for Re=2xlOs, Y2/'Yi=2) 4.8.-12 Temperature profiles (for Re=5xlO5, Y2/Yi=2) 4.8.-13 Effect of Reynolds number (for Pr=0.0054, Y2/Yi=l-5) 4.8.-14 Effect of Reynolds number (for Pr=0.0054, Y2/Yi=l-5) 4.8.-15 Effect of Reynolds number (for Pr=0.0054, Y2/ i=l-5) 4.8.-16 Temperature profiles (for Re=6.000, Y2/Yi=l-5) 4.8.-17 Temperature profiles (for Re=104, Y2/Yi=l-5) 4.8.-18 Temperature profiles (for Re=4xlO4, Y2/Yi=l-5) 4.8.-19 Temperature profiles (for Re=10s, Y2/Yi=l»5) 4.8.-20 Temperature profiles (for Re=5xlO5, Y2/Yi=l-5) 4.8.-21 Variation of thermal entrance length with Re 4.8.-22 Effect of Prandtl number (for Re=5xl04, Y2/Yi=2) 4.8.-23 Effect of Prandtl number (for Re=5xlO4, Y2/Yi=l-5) 4.8.-24 Effect of radius ratio (for Re=5xlO4, Pr=C.OO52) 4.8.-25 Comparison of results 4.8.-26 Comparison of fully developed Nusselt number 4.11.-1 Variation of Nu for the annulus 4.11.-2 Variation of Nu with element length (for Re=5xlO4) 4.11.-3 Variation of Nu with element length (for Re=104) 4.11.-4 Effect of pitch to diameter ratio (for L=100De) 4.11.-5 Effect of pitch to diameter ratio (for L=30De) 4.11.-6 Effect of amplitude (for L=20De) 4.11.-7 Effect of amplitude (for I=100De) 4.11.-8 Axial temperature distribution 4.12.-1 Comparison of temperature profiles 4.12.-2 Comparison of Nusselt numbers 4.13.-1 Comparison of temperature profiles 5.4.-1 Na2 loop flow sheet 5.4.-2 Test section 5.4.-3 Cross section of test section 5.4.-4 Block diagram of measurement system 5.7.-1 Nomenclature of test section 5.9.-1 Temperature profiles (Pr - 0.0059, Re « 6,000) 5.9.-2 Temperature profiles (Pr - 0.0059, Re - 8,000} 5.9.-3 Temperature profiles (Pr - 0.0054, Re » 2 x 104) 5.9.-4 Temperature profiles (Pr • 0.0054, Re - 5 x 104) 5.9.-5 Temperature profiles (Pr - 0.0054, Re - 6 x 104) 5.9.-6 Variation of Nusselt number with Re (Pr * 0.0059, Re « 6,000 - 10 ) 5.9.-7 Variation of Nusselt number with Re (Pr * 0.0059, Re - 2 x 10 - 5.5 x 104) 5.9.-8 Variation of Nusselt number with Re (Pr - 0.0054, Re - 6,000 - JO4) 5.9.-9 Variation of Nusselt number with Re (Pr - 0.0054, Re « 2 x 104 - 6 x 104) 5.9.-10 Variation of Nusselt number with Pr (Re - 104) 5.9.-11 Variation of Nusselt number with Pr (Re • 5 x 104) 5.9.-12 Effect of heat flux 5.9.-13 Wall temperature distribution 5.9.-14 Comparison of Nusselt numbers 5.9.-15 Comparison of temperature profiles 5.9.-16 Temperature evolution for a period T » 60 sec.