Heat transfer crisis and fluid distribution in bundles of rods in the area of dispersed-annular flow mode


Аuthors

Boltenko E. A., Davydov M. V.

Joint Stock Company «Electrogorsk Research and Engineering Center on NPP safety» (JSC «EREC»), Saint Constantine str., 6, Electrogorsk, Moscow region, 142530 Russia

Abstract

The article presents the results of earlier performed studies on the fluid consumption in the near-wall film in conditions equilibrium phase distribution. A mass transfer diagram for non-heated channels was plotted. The technique for determining the amount of liquid in the near-wall film of a two-phase dispersed-annular flow on the heat-release surface for pipes is de-scribed. The technique is based on the experimentally established unique dependence of the to-tal mass exchange between the flow core and near-wall film and critical heat flows values in the area of the dispersed-annular mode; fluid consumption in the flow core and film with boundary conditions in the beginning of the dispersed-annular mode and parameters in the place of the heat transfer crisis origin.

This method is based on the experimentally established explicit relationship between the in-tensity of the total mass transfer between the flow core and the wall film and the critical heat fluxes in the region of the dispersed-annular regime, between the fluid flow rates in the flow core and the film and the boundary conditions at the beginning of the formation of the dis-persed-annular regime and the parameters at the site of the heat transfer crisis. The dependences for determining the fraction of liquid in a wall film for pipes in the area of the dispersed-annular modeare presented. A mass transfer diagram was plotted in the entire area of the dispersed-annularmode existence for heated channels. An approach, on which basis technique elaboration for computing heat transfer crisis in assemblies is possible, is described. Calculations of fluid consumption in the films of the fuel element surfaces in characteristic cells of a seven-rod as-sembly were performed. Mass steam contents x were set based on the experimental values, ob-tained by the isokinetic sampling technique.Comparison of the calculated liquid flow rates in the core and the total liquid flow rates in the cells (measured by the isokinetic sampling tech-nique) near the total flow consumption line reveals that the calculated and experimental values are quite close. A satisfactory agreement was obtained between the calculated and experimental values of the steam content xп at the bundle outlet.

Keywords:

mass transfer diagram, dispersed-annular mode, flow core, critical heat flux, heat transfer crisis, flow-rates in film, seven-rod assembly, isokinetic sampling method.

References

  1. Boltenko E.A. Krizis Teplootdachi i Raspredelenie Zhidkosti v Parogeneriruyushhikh Kanalakh [Heat transfer crisis and fluid distribution in steam generating channels]. Moscow: Raduga, 2015. 280 p. In Russ.

  2. Nigmatulin R.I. Dinamika Mnogofaznykh Sred [The dy-namics of multiphase media]. Moscow: Nauka, 1987. 359 p. In Russ.

  3. Yagov V.V., Minko M.V. Entrained liquid fraction calcula-tion in adiabatic disperse-annular flows at low rate in film. Thermal Engineering, 2016, vol. 63, no. 4, pp. 288–293.

  4. Hewitt G.F., Hall-Taylor N.S. Annular Two-Phase Flow. Oxford, Pergamon Press, 1970, 310 p. (Russ. ed. Hewitt G.F., Hall-Taylor N.S. Kol’tsevye dvukhfaznye techeniya. Mos-cow: Energiya, 1974. 408 p.)

  5. Minko M.V. Issledovanie mekhanizmov protsessa i raz-rabotka metodov rascheta teploobmena dvukhfaznykh potokov v kanalakh. Diss. cand. tech. nauk [Study of the mechanisms of the process and development of methods for calculating the heat transfer of two-phase flows in channels. PhD thesis]. Moscow, MPEI, 2012. 155 p. In Russ.

  6. Kaznovsky S.P., Pometko R.S., Pashichev V.V. Issledo-vanie raspredeleniya zhidkosti v dispersno-kol’tsevom rezhime techeniya v trube pri nizkom davlenii [The study of the distribution of liquid in the dispersed-annular mode of flow in the pipe at low pressure]. Preprint FEI-432, IPPE, Obninsk, 1973. 12 p. In Russ.

  7. Boltenko E.A., Gorban L.M., Pashichev V.V., Peskov O.L., Pometko R.S. Raspredelenie zhidkosti mezhdu yadrom potoka i pristennoj plenkoj pri dispersno-kol’tsevom rezhime techeniya vody i freona-12 v neobogrevaemykh trubakh [The distribution of fluid between the core of the stream and the wall film in the dispersed-annular mode of flow of water and freon-12 in un-heated pipes]. Preprint FEI-847, Obninsk, 1978. 12 p. In Russ.

  8. Milashenko V.I. Izmerenie raskhodov faz v dispersno-kol’tsevom parovodyanom potoke [Phase flow rate measure-ment in a dispersed-annular steam-water flow]. Voprosy gaz-otermodinamiki ehnergoustanovok [Issues of gas thermody-namics of power plants]. Kharkiv, 1976, issue 3, pp. 21–28. In Russ.

  9. Boltenko E.A., Pometko R.S. Raskhod zhidkosti v pristen-noj plenke pri dispersno-kol’tsevom rezhime techeniya vody i freona-12 v trube [The flow rate of the liquid in the wall film during the dispersed-annular flow regime of water and freon-12 in the pipe]. Teplofizika visokih temperatur — High temperature, 1979, vol. 17, no. 3, pp. 563–567. In Russ.

  10. Nigmatulin B.I. Heat-transfer crisis and discharge of liquid in a film during passage of dispersed-annular flows. High Temperature, 1979, vol. 17, no. 6, pp. 1040–1044.

  11. Doroshuk V.E. Krizisy teploobmena pri kipenii vody v trubakh [Heat exchange crises during boiling water in pipes]. Moscow: Energoatomizdat, 1983. 256 p. In Russ.

  12. Boltenko E.A., Peskov O.L., Pometko R.S. Raskhod zhidkosti v yadre dispersno-kol’tsevogo potoka i krizis tep-lootdachi [Liquid flow rate in the core of a dispersed-annular flow and heat transfer crisis]. Preprint FEI-983, Ob-ninsk, 1980. 15 p. In Russ.

  13. Boltenko E.A., Pometko R.S. Sposob opredeleniya kolichest-va zhidkosti v pristennoj plenke dvukhfaznogo potoka [The method of determining the amount of liquid in the wall film of a two-phase flow]. Patent USSR no. 803646, 1979. In Russ.

  14. Kaznovsky S.P., Pometko R.S., Pashichev V.V. Mekhanizm krizisa teplootdachi pri parosoderzhaniyakh ХХгр ∠

  15. v dis-persno-kol’tsevom rezhime techeniya [The mechanism of heat transfer crisis at a steam quality x<xgr in a dispersed-annular flow regime]. Preprint FEI-432, Obninsk, 1973. 13 p. In Russ.

  16. Smolin V.N., Poliakov V.K. Kriticheskij teplovoj potok pri prodol’nom obtekanii puchka sterzhnej [Critical heat flux during longitudinal flow around a bundle of rods]. Teploen-ergetika — Teploenergetika, 1967, no. 4, pp. 21–27. In Russ.

  17. Arkhipov A.P., Ornatskiy A.P., Mayevskiy E.M. Issledo-vanie raspredeleniya massovoj skorosti i ehntal’pii potoka po secheniyu semisterzhnevogo puchka [Study into the dis-tribution mass and enthalpy flow in the cross section of a 7-rod fuel assembly]. Teploenergetika — Teploenergetika, 1981, no. 7, pp. 64–66. In Russ.

  18. Arkhipov A.P. Issledovanie raspredeleniya teplogidrav-licheskikh parametrov potoka v puchkakh tsilindricheskikh teplovydelyayushhikh sterzhnej. Diss. kand. tekhn. nauk [Study of distribution of thermohydraulic flow parameters in bundles of cylindrical fuel rods. PhD thesis]. Kiyev, 1981. 181 p. In Russ.

mai.ru — informational site of MAI

Copyright © 2009-2024 by MAI