Satish Kumar DHURANDHAR, Shobha Lata SINHA, Shashi Kant VERMA

Numerical simulation to study mixing vane spacer effects on heat transfer performance of supercritical pressure fluid in an annular channel

The spacer represents an essential part in the nuclear fuel rod. Spacer grid with mixing vanes in fuel rod bundle of nuclear reactor core has a significant impact on heat transfer perfor-mance in downstream to grid spacer. Grid Spacers are located on the nuclear fuel rod as-sembly to hold suitable clearance among the rods in a bundle. The objective of this paper is to study the enhanced heat transfer performance of R134a at supercritical pressure 4.5 MPa near downstream to mixing vane spacer in a vertical channel of annular flow. A spacer of 0.38 blockage ratio with mixing vanes, situated at mid-span of an annular channel is used in the present work. Numerical simulations have been accomplished for spacer with mixing vane and spacer without mixing vane in an annular channel by using commercial CFD (Computa-tional fluid dynamics) code ANSYS Fluent. The present investigation represents the compara-tive study for spacer with mixing vane and spacer without mixing vane effects on heat transfer and flow field characteristics in a downstream direction for mass flow-rate 0.41469 kg/s and heat flux 160 kW/m2. The results indicate that spacer with mixing vane has notable influence on heat transfer performance and flow field characteristics downstream of mixing vane spacer as compared to spacer without mixing vane. Wall temperature fall and increase of coefficient of heat transfer are significantly greater adjacent to spacer downstream. Spacer influence in the improvement of the heat transfer is noted up to distance X/D = 40 downstream and then flow is found as fully developed.

Keywords:

Supercritical Pressure, Mixing Vane Spacer Heat Transfer, CFD, Vertical Annular Flow,

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REFERENCES
[1] Doe US. Nuclear Energy Advisory Committee and Generation IV International Forum. A Technology Roadmap for Generation IV Nuclear Energy System; 2002. Available at: https://www.gen-4.org/gif/upload/docs/application/pdf/2013-09/genivroadmap2002.pdf. Accessed Nov 6, 2023.
[2] Wang H, Bi Q, Yang Z, Gang W, Hu R. Experimental and numerical study on the enhanced effect of spiral spacer to heat transfer of supercritical pressure water in vertical annular channels. Appl Therm Eng 2012;48:436–445. [CrossRef]
[3] Ishiwatari Y, Hongo I, Oka Y, Morooka S, Saito T, Ikejiri S. Numerical analysis of heat transfer enhancement by grid spacers in supercritical water. NURETH-13: 13. international topical meeting on nuclear reactor thermal hydraulics; Kanazawa, Ishikawa (Japan); Shimbashi, Minato, Tokyo; 2009.
[4] Gang W, Bi Q, Yang Z, Wang H, Zhu X, Hao H, et al. Experimental investigation of heat transfer for supercritical pressure water flowing in vertical annular channels. Nucl Eng Des 2011;241:4045–4054. [CrossRef]
[5] Zhu Y, Laurien E. Numerical investigation of supercritical water cooling channel flows around a single rod with a wrapped wire. Proceedings of ICAPP, San Diego, California, USA; 2010. [CrossRef]
[6] Yamagata K, Nishikawa K, Hasegawa S, Fujii T, Yoshida S. Forced convective heat transfer to supercritical water flowing in tubes. Int J Heat Mass Transf 1972;15:2575–2593. [CrossRef]
[7] Swenson HS, Carver JR, Kakarala CR. Heat transfer to supercritical water in smooth-bore tubes. J Heat Transf 1965;87:477–484. [CrossRef]
[8] Zhu X, Morooka S, Oka Y. Numerical investigation of grid spacer effect on heat transfer of supercritical water flows in a tight rod bundle. Int J Therm Sci 2014;76:245–257. [CrossRef]
[9] Xiao Y, Pan J, Gu H. Numerical investigation of spacer effects on heat transfer of supercritical fluid flow in an annular channel. Int J Heat Mass Transf 2018;121:343–353. [CrossRef]
[10] Holloway MV, McClusky HL, Beasley DE, Conner ME. The effect of support grid features on local, single-phase heat transfer measurements in rod bundles. J Heat Transf 2004;126:43–53. [CrossRef]
[11] Bhattacharjee S, Ricciardi G, Viazzo S. Comparative study of the contribution of various PWR spacer grid components to hydrodynamic and wall pressure characteristics. Nucl Eng Des 2017; 317:22–43. [CrossRef]
[12] Miller DJ, Cheung FB, Bajorek SM. On the development of a grid-enhanced single-phase convective heat transfer correlation. Nucl Eng Des 2013;264:56–60. [CrossRef]
[13] Ikeda K. CFD application to advanced design for high efficiency spacer grid. Nucl Eng Des 2014;279:73–82. [CrossRef]
[14] Yao SC, Hochreiter LE, Leech WJ. Heat-transfer augmentation in rod bundles near grid spacers. J Heat Transf 1982;104:76–81. [CrossRef]
[15] Wang Y, Ferng YM, Sun LX. CFD assist in the design of spacer-grid with mixing-vane for a rod bundle. Appl Therm Eng 2019;149:565–577. [CrossRef]
[16] Tanase A, Groeneveld DC. An experimental investigation on the effects of flow obstacles on single phase heat transfer. Nucl Eng Des 2015;288:195–207.
[17] Eter A, Groeneveld D, Tavoularis S. Convective heat transfer in supercritical flows of CO2 in tubes with and without flow obstacles. Nucl Eng Des 2017;313:162–176. [CrossRef]
[18] Qu W, Yao W, Xiong J, Cheng X. Experimental study of pressure loss in a 5 × 5–rod bundle with the mixing vane spacer grid. Front Energy Res 2021;9:675494. [CrossRef]
[19] Yang P, Zhang T, Hu L, Liu L, Liu Y. Numerical investigation of the effect of mixing vanes on subcooled boiling in a 3 × 3 rod bundle channel with spacer grid. Energy 2021;236:121454. [CrossRef]
[20] Huang H, Chen C, Liu L, Liu Y, Li L, Yu H, et al. Study on flow boiling characteristics in rectangle channel after the formation of blisters. Front Energy Res 2021;9:676586. [CrossRef]
[21] Wang Y, Wang M, Ju H, Zhao M, Zhang D, Tian W, et al. CFD simulation of flow and heat transfer characteristics in 5×5 fuel rod bundles with spacer grids of advanced PWR. Nucl Eng Technol 2020;52:1386–1395. [CrossRef]
[22] Ahmadpour V, Rezazadeh S, Mirzaei I, Mosaffa AH. Numerical investigation of horizontal magnetic field effect on the flow characteristics of gallium filled in a vertical annulus. J Therm Eng 2021;7:984–999. [CrossRef]
[23] Verma TN, Sinha SL. Experimental and numerical investigation of contaminant control in intensive care unit: A case study of Raipur, India. J Therm Eng 2020;6:736–750. [CrossRef]
[24] Xiong J, Qu W, Zhang T, Chai X, Liu X, Yang Y. Experimental investigation on split-mixing-vane forced mixing in pressurized water reactor fuel assembly. Ann Nucl Energy 2020;143:107450. [CrossRef]
[25] Zhang S, Gu H, Cheng X, Xiong Z. Experimental study on heat transfer of supercritical Freon flowing upward in a circular tube. Nucl Eng Des 2014;280:305–315. [CrossRef]
[26] Cheng H, Zhao J, Rowinski MK. Study on two wall temperature peaks of supercritical fluid mixed convective heat transfer in circular tubes. Int J Heat Mass Transf 2017;113:257–267. [CrossRef]
[27] ANSYS Inc. Ansys Fluent 12.0 User's Guide. 2009. Available at: https://www.afs.enea.it/project/neptunius/docs/fluent/html/ug/main_pre.htm. Accessed Nov 7 2023.
[28] Jaromin M, Anglart H. A numerical study of heat transfer to supercritical water flowing upward in vertical tubes under normal and deteriorated conditions. Nucl Eng Des 2013;264:61–70. [CrossRef]
[29] Palko D, Anglart H. Theoretical and numerical study of heat transfer deterioration in high performance light water reactor. Sci Technol Nucl Install 2008;2008:1–5. [CrossRef]
[30] Liu CC, Ferng YM, Shih CK. CFD evaluation of turbulence models for flow simulation of the fuel rod bundle with a spacer assembly. Appl Therm Eng 2012;40:389–396. [CrossRef]
[31] Podila K, Rao Y. CFD modeling of turbulent flows through 5×5 fuel rod bundles with spacer-grids. Ann Nucl Energy 2016;97:86–95. [CrossRef]
[32] Sohag FA, Mohanta L, Cheung FB. CFD analyses of mixed and forced convection in a heated vertical rod bundle. Appl Therm Eng 2017;117:85–93. [CrossRef]
[33] Cheng S, Chen H, Zhang X. CFD analysis of flow field in a 5×5 rod bundle with multi-grid. Ann Nucl Energy 2017;99:464–470. [CrossRef]