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A NUMERICALLY RESEARCH ON ENERGY LOSS EVALUATION IN A CENTRIFUGAL PUMP SYSTEM BASED ON LOCAL ENTROPY PRODUCTION METHOD

ABSTRACT
Inspired by wide application of the second law of thermodynamics to flow and heat transfer devices, local entropy production analysis method was creatively introduced into energy assessment system of centrifugal water pump. Based on Reynolds stress turbulent model and energy equation model, the steady numerical simulation of the whole flow passage of one IS centrifugal pump was carried out. The local entropy production terms were calculated by user defined functions, mainly including wall entropy production, turbulent entropy production, and viscous entropy production. The numerical results indicated that the irreversible energy loss calculated by the local entropy production method agreed well with that calculated by the traditional method but with some deviations which were probably caused by high rotatability and high curvature of impeller and volute. The wall entropy production and turbulent entropy production took up large part of the whole entropy production about 48.61% and 47.91%, respectively, which indicated that wall friction and turbulent fluctuation were the major factors in affecting irreversible energy loss. Meanwhile, the entropy production rate distribution was discussed and compared with turbulent kinetic energy dissipation rate distribution, it showed that turbulent entropy production rate increased sharply at the near wall regions and both distributed more uniformly. The blade region in leading edge near suction side, trailing edge and volute tongue were the main regions to generate irreversible exergy loss. This research broadens a completely new view in evaluating energy loss and further optimizes pump using entropy production minimization.
KEYWORDS
PAPER SUBMITTED: 2015-07-02
PAPER REVISED: 2016-05-30
PAPER ACCEPTED: 2016-06-10
PUBLISHED ONLINE: 2016-07-12
DOI REFERENCE: https://doi.org/10.2298/TSCI150702143H
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2017, VOLUME 21, ISSUE 3, PAGES [1287 - 1299]
REFERENCES
  1. Bogdanović-Jovanović, Jasmina B., et al, Pumps used as turbines power recovery, energy efficiency, CFD analysis, Thermal Science, 18 (2014), 3, pp. 1029-1040.
  2. Zhang, Desheng, et al, Numerical investigation of blade dynamic characteristics in an axial flow pump, Thermal Science, 17 (2013), 5, pp. 1511-1514.
  3. Mahian, Omid, et al, Design of a vertical annulus with MHD flow using entropy generation analysis, Thermal Science, 17 (2013), 4, pp. 1013-1022.
  4. Malvandi, Amir, et al, Series solution of entropy generation toward an isothermal flat plate, Thermal Science, 16 (2012), 5, pp. 1289-1295.
  5. Atashafrooz, Meysam, Nassab Abdolreza Seyyed Gandjalikhan, and Babak Amir Ansari, Numerical investigation of entropy generation in laminar forced convection flow over inclined backward and forward facing steps in a duct under bleeding condition, Thermal Science, 18 (2014), 2, pp. 479-492.
  6. Zhang, H-C., B. Schmandt, and H. Herwig, Determination of loss coefficients for micro-flow devices: A method based on the second law analysis (SLA), ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, American Society of Mechanical Engineers, 2009.
  7. Herwig, H., D. Gloss, and T. Wenterodt, A new approach to understanding and modelling the influence of wall roughness on friction factors for pipe and channel flows, Journal of Fluid Mechanics, 613 (2008), pp. 35-53.
  8. Kock, Fabian, and Heinz Herwig, Entropy production calculation for turbulent shear flows and their implementation in CFD codes, International Journal of Heat and Fluid Flow, 26 (2005), 4, pp. 672-680.
  9. Kock, Fabian, and Heinz Herwig, Local entropy production in turbulent shear flows: a high-Reynolds number model with wall functions, International Journal of Heat and Mass Transfer, 47 (2004), 10, pp. 2205-2215.
  10. Shen Weidao, Jiang Zhimin, Tong Jungeng, Engineering Thermodynamics, Higher Education Press, 3rd ed. Beijing, China, 2001. (In Chinese)
  11. Förste J. Spurk, JH, Strömungslehre, 1989.
  12. Kock, Fabian, Bestimmung der lokalen Entropieproduktion in turbulenten Strömungen und deren Nutzung zur Bewertung konvektiver Transportprozesse, Shaker, 2003.
  13. Herwig, H., and F. Kock, Direct and indirect methods of calculating entropy generation rates in turbulent convective heat transfer problems, Heat and mass transfer, 43 (2007), 3, pp. 207-215.
  14. Duan Lu, Wu Xiaolin, and Ji Zhongli, Application of entropy generation method for analyzing energy loss of cyclone separator, CIESC Journal, 65 (2014), 2, pp. 583-592. (In Chinese)
  15. Xiaomin, Zhang Xiang Wang Yang Xu, and Wang Hongyu. Energy conversion characteristic within impeller of low specific speed centrifugal pump, Transactions of the Chinese Society for Agricultural Machinery 7 (2011), pp. 016. (In Chinese)
  16. Zhou, Xin, et al. The Impeller Improvement of the Centrifugal Pump Based on BVF Diagnostic Method, Advances in Mechanical Engineering, 6 (2014), pp. 464363, DOI No. 10.1155.
  17. Zhou, Xin, et al, The Optimal Hydraulic Design of Centrifugal Impeller Using Genetic Algorithm with BVF, International Journal of Rotating Machinery, 2014 (2014), DOI No.10.1155.
  18. Li Wenguang, Comparisons among several empirical formula of hydraulic efficiency, Mechanical and electrical technology, 2 (1999), pp. 1-4. (In Chinese)

© 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