THERMAL SCIENCE

International Scientific Journal

THE PROCESSES OF VAPORIZATION IN THE POROUS STRUCTURES WORKING WITH THE EXCESS OF LIQUID

ABSTRACT
The processes of vaporization in porous structures, working with the excess of liquid are investigated. With regard to the thermal power plants new porous cooling system is proposed and investigated, in which the supply of coolant is conducted by the combined action of gravity and capillary forces. The cooling surface is made of stainless steel, brass, copper, bronze, nickel, alundum and glass, with wall thickness of (0.05-2)•10-3 m. Visualizations of the processes of vaporization were carried out using holographic interferometry with the laser system and high speed camera. The operating conditions of the experiments were: water pressures (0.01-10) MPa, the temperature difference of sub-cooling (0-20)°C, an excess of liquid (1-14) of the steam flow, the heat load (1-60)•104 W/m2, the temperature difference (1-60)°C and orientation of the system (± 0 - ± 90) degrees. Studies have revealed three areas of liquid vaporization process (transitional, developed and crisis). The impact of operating and design parameters on the integrated and thermal hydraulic characteristics was defined. The optimum (minimum) flow rate of cooling fluid and the most effective type of mesh porous structure were also defined.
KEYWORDS
PAPER SUBMITTED: 2016-03-26
PAPER REVISED: 2016-12-11
PAPER ACCEPTED: 2016-12-11
PUBLISHED ONLINE: 2017-01-14
DOI REFERENCE: https://doi.org/10.2298/TSCI160326313G
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2017, VOLUME 21, ISSUE 1, PAGES [363 - 373]
REFERENCES
  1. Polyaev V.M., et al., Methods of Monitoring Energy Processes, Experimental Thermal and Fluid science, International of Thermodynamics, Experimental Heat Transfer, and Fluid Mechanics. Avenue of the Americas, New York, 1995, V.10, April, pp. 273 - 286.
  2. Polyaev V.M, Genbach A.A. Heat Transfer in a Porous System in the Presence of Both Capillary and Gravity Forces, Thermal Engineering, 40, (1993), 7, pp. 551-554.
  3. Polyaev V. M., et al., A limit condition of a surface at thermal influence, Teplofizika vysokikh temperatur (TVT) (in Russian language), 29, (1991) 5, pp. 923-934.
  4. Polyaev V.M., Genbach A.A. Control of Heat Transfer in a Porous Cooling System, Second world conference on experimental heat transfer, fluid mechanics and thermodynamics. 1991, Dubrovnik, Yugoslavia, 23-28 June. pp. 639-644.
  5. Polyaev V. M., et al., Processes in the porous elliptic heat exchanger, Isvestiya vuzov. Mashinostroyenie, (in Russian language), (1991), 4-6, pp. 73-77.
  6. Polyaev V.M, Genbach A.A. Analysis of laws for friction and heat exchange in the porous structure, Bulletin of MGTU. Mechanical engineering series, (in Russian language), (1991), 4, pp. 86-96. (Поляев В.М.,
  7. Polyaev V. M., et al., The influence of pressure on the intensity of heat transfer in a porous system, Isvestiya vuzov. Mashinostroyenie, (in Russian language), (1992), 4-6, pp. 68-72.
  8. Genbach A.A., Bakhytzhanov I.B., Protection against earthquakes TPP bases with the help of porous geo screens, Poisk, MES of RK, (in Russian language), 2 (2012), 1, pp. 289-298.
  9. Genbach A.A., Danilchenko I. Porous desuperheater steam boilers, Promyshlennost Kazakhstana, (in Russian language), 70 (2012), 1, pp. 72-75.
  10. Genbach A.A., Olzhabayeva K. S. Visualization of thermal impact on porous material in thermal energy installations of power plants, Bulletin of the National RK engineering academy, 45, (2012), 3 ,pp. 63-67
  11. Genbach A.A., Islamov F.A. Research of the nozzle fillets in electrical installations,Vestnik KazNTU, (in Russian language), 97, (2013), 3, pp. 245-248.
  12. Genbach A.A., Islamov F.A. Modeling process grazing turbine, Vestnik KazNTU, (in Russian language), 100, (2013), 6, pp.235-240.
  13. Polyaev V.M., Genbach A.A. Field of application of porous system, Isvestiya vuzov, Energetika, (in Russian language), (1991), 12, pp. 97-101.
  14. Polyaev V.M., Genbach A.A. Control of heat transfer in porous structures. Proceedings of the Russian Academy of Sciences. Power Engineering and transport, (in Russian language), 38 (1992), 6, pp. 105-110.
  15. Jamialahmadi M., et al., Experimental and theoretical studies on subcooled flow boiling of pure liquids and multicomponent mixtures, Intern. J Heat Mass Transfer. 51 (2008), pp. 2482-2493
  16. Ose Y., Kunnugi T. Numerical study on subcooled pool boiling, Progr in Nucl. Sci. and Technology. 2, (2011), pp. 125-129.
  17. Krepper E, et al., CFD modeling subcooled boiling-concept, validation and application to fuel assembly design, Nucl. Eng. and Design. (2007), 237, pp. 716-731.
  18. Ovsyanik A.V. Modelling of processes of heat exchange at boiling liquids, Gomel State Technical University named after Sukhoy P.O., Gomel, (in Russian language). (2012), P. 284
  19. Alekseik O. S., Kravets V. Yu. Physical model of boiling on porous structure in the limited space, Eastern-European Journal of Enterprise Technologies, 64, (2013), 4/8, pp. 26-31.

© 2017 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence