10.1007/s40095-015-0172-2

Unification perspective of finite physical dimensions thermodynamics and finite speed thermodynamics

  1. Department of Engineering Thermodynamics, Engines, Thermal and Refrigeration Equipments, University Politehnica of Bucharest, Bucharest, 060042, RO
  2. University of Lorraine, LEMTA, URA CNRS, Vandœuvre Cedex, 54518, FR
Cover Image

Published in Issue 2015-04-15

How to Cite

Petrescu, S., Feidt, M., Enache, V., Costea, M., Stanciu, C., & Boriaru, N. (2015). Unification perspective of finite physical dimensions thermodynamics and finite speed thermodynamics. International Journal of Energy and Environmental Engineering, 6(3 (September 2015). https://doi.org/10.1007/s40095-015-0172-2

HTML views: 36

PDF views: 113

Abstract

Abstract The paper studies the possibility of unifying the two branches of the irreversible engineering thermodynamics, namely finite physical dimensions thermodynamics (FPDT) and finite speed thermodynamics (FST), aiming to take into account their benefits and successes and to eliminate as much as possible their disadvantages. Actually, the two branches have the same goal, that of optimizing the performance of thermal machines and they were developed almost in parallel. Analysis of thermal machines cycles using the FPDT is based on the first and second law of thermodynamics, in the presence of the external irreversibility generated by the heat transfer at finite temperature difference at the thermal reservoirs and internal irreversibility, using the internal source of entropy considered as parameter or function to be specified. The FST is based on the mathematical expression of the first law for process with finite speed that involves three causes of internal irreversibility, namely the finite speed of the piston, internal friction and throttling. The direct method is used in the analysis of thermal machines cycles to provide analytical expression of the machine performance (efficiency and power) as a function of the speed of the process. The significant progress of these two branches of irreversible engineering thermodynamics makes their unification a desirable outcome. We hope that the new model yielded from this study will provide an even more important tool for engineers that will help their attempt to a better design and optimization of thermal machines.

Keywords

  • Finite physical dimensions thermodynamics,
  • Finite speed thermodynamics,
  • Internal and external irreversibility,
  • Source of internal entropy,
  • Thermal machines

References

  1. Feidt, M.: Thermodynamics and energetic optimization of systems and processes. TEC and DOC, Paris (1st edition 1987, 2nd edition 1996)
  2. Costea, M.: Performances improvement of heat exchangers in view of thermodynamic optimization of Stirling machine. heat transfer in non-steady-state regime in porous media (FL). Ph.D. Thesis, UP Bucharest, Romania and UHP Nancy 1, France (1997)
  3. Feidt et al. (2007) Optimization of the direct Carnot cycle 27(5–6) (pp. 829-839) https://doi.org/10.1016/j.applthermaleng.2006.09.020
  4. Petre, C.: Use of thermodynamics with finite speed for studying and optimization of Carnot cycle and Stirling machines (RL), Ph.D. Thesis, UP Bucharest, Romania and UHP Nancy 1, France (2007)
  5. Petre et al. (2009) A model for study and optimization of real-operating refrigeration machines 33(2) (pp. 173-179) https://doi.org/10.1002/er.1433
  6. Feidt and Costea (2012) Energy and exergy analysis and optimization of combined heat and power systems (pp. 3701-3722)
  7. Feidt (2013) Hermès
  8. Petrescu et al. (2002) Application of the direct method to irreversible stirling cycles with finite speed 26(7) (pp. 589-609) https://doi.org/10.1002/er.806
  9. Petrescu et al. (2010) A methodology of computation, design and optimization of solar stirling power plant using hydrogen/oxygen fuel cells 35(2) (pp. 729-739) https://doi.org/10.1016/j.energy.2009.10.036
  10. Petrescu, S., Costea, M., Petrescu, V., Malancioiu, O., Boriaru, N., Stanciu, C., Banches, E., Dobre, C., Maris, V., Leontiev, C.: Development of thermodynamics with finite speed and direct method. AGIR Bucharest, p. 362 (2011)
  11. Petrescu et al. (2012) The direct method from thermodynamics with finite speed used for performance computation of a quasi-Carnot irreversible cycles, part I. Evaluation of coefficient of performance and power for refrigeration machines with mechanical compression of vapor 63(1) (pp. 74-81)
  12. Petrescu, S., Petre, C., Costea, M., Mladin, E.C., Harman, C., Feidt, M.: Entropy generation calculation for the reversed cycle machine using the finite speed thermodynamics and the direct method. ECOS’08, Cracovia, Poland, Ed. A. Ziebik, Z. Kolenda, W. Stanek, 1, 121–128 (2008)
  13. Petrescu, S., Dobre, C., Tirca-Dragomirescu, G., Costea, M.: Performance evaluation of a reversed quasi-Carnot irreversible cycle using the direct method from finite speed thermodynamics. COFRET 2012-Conference Proceedings, Sozopol, Bulgaria, 244–249 (2012)
  14. Dobre, C., Grosu, L., Costea, M., Martaj N.: Beta type Stirling engine. schmidt and finite physical dimensions thermodynamics methods faced to experiments. Environ Eng Manag J.
  15. http://omicron.ch.tuiasi.ro/EEMJ/accepted.htm
  16. (in print 2014)
  17. Petrescu, S., Feidt, M., Costea, M., Petre, C., Boriaru, N.: Entropy generation calculation in an irreversible thermal engine with isothermal heat exchange at source and sink using the thermodynamics with finite speed and the direct method, COFRET’08, Nantes, France, and Termotehnica Journal 2 (2008)