Потери эксергетической мощности в теплоутилизационных системах с пластинчатыми теплоутилизаторами

Authors

  • Н. М. Фиалко
  • А. И. Степанова
  • Р. А. Навродская

Abstract

LOSS OF EXERGENCY CAPACITY IN HEAT UTILIZATION SYSTEMS WITH PLATE INSULATED HEAT UTILIZERS

N. Fialko, А. Stepanovа, R. Navrodska

Abstract. The problem of developing efficient technologies for utilizing the heat of waste gases from power plants is an important part of the overall problem of modernizing Ukraine's energy sector. Development of high-quality heat recovery equipment for power plants of various types is inextricably linked with the development and use of effective methods for optimizing heat recovery systems. These methods are quite diverse and can be based on complex approaches that include exergy methods combined with methods of thermodynamics of irreversible processes. This determines the relevance of the work.

 The purpose of the work is to increase the efficiency of the plate heat exchangers by reducing the losses of exergy power.

 The work analyses the loss of exergy power in heat conduction processes during the transfer of heat through the cross-section of an unlimited plate. An unlimited plate simulated the gas-air plate heat exchanger plate. The results of numerical calculations of losses of exergic power in heat conduction processes in an unbounded plate under boundary conditions of the third kind are presented.

 The mathematical model of the studied processes includes the exergy equation, the balance equation of exergy and entropy, the equation of continuity of a three-phase thermodynamic system with a change in the concentration of one of the phases, the equation of phase motion, the energy equation, the balance equation for enthalpies, the Gibbs equation, and the heat equation for boundary conditions of the third kind.

 When obtaining formulas for calculating the losses of exergy power, a local differential equation of the exergy balance of a three-phase system with a variable concentration of one of the phases is used. The derivation of this equation is presented in [1]. In the equation, one of the terms determines the loss of exergy power in the system, these loss are caused by the irreversibility of the processes and are related to the thermal conductivity, phase viscosity, phase-to-phase heat exchange, and friction between phases. Based on this equation and the solution of the heat equation under boundary conditions of the third kind for an unbounded plate, formulas are obtained for calculating the loss of exergy power and the losses in the gas-air plate heat exchanger are calculated.

Key words: heat recovery system, heat conduction processes, loss of exergy power

References

D’yarmati, I. (1974). Neravnovesnaya termodinamika [Nonequilibrium thermodynamics]. Moskow: «Mir», 247.

Pod red. V. M. Brodyanskogo. (1967). Eksergeticheskiy metod i ego prilozheniya [The exergy method and its applications]. Moskow: «Mir», 247.

Belousov, V.S. (2003). Razvitiye metodov eksergeticheskogo analiza i issledovaniye protsessov v odnofaznykh i dispersnykh sredakh na osnove neravnovesnoy termodinamiki: avtoref. dis. d-ra tekhn. nauk [Development of methods for exergetic analysis and study of processes in single-phase and disperse media on the basis of nonequilibrium thermodynamics: the author's abstract. UGTU – UPI. Ekaterinburg, 48.

Stepanova, A. I. (2016). Makroskopicheskaya model’ trekhfaznoy termodinamicheskoy sistemy peremennoy massy [Macroscopic model of a three-phase thermodynamic system of variable mass ]. Energetika і avtomatika, 4, 133-144.

Pekhovich, A. I., Zhidkikh, V. M. Raschety teplovogo rezhima tverdykh tel [Calculations of the thermal regime of solids]. (1976). Leninhrad.: Energiya,– 351.

Downloads

Published

2017-10-26

Issue

No. 3 (2017)

Section

Статті

License

Relationship between right holders and users shall be governed by the terms of the license Creative Commons  Attribution – non-commercial – Distribution On Same Conditions 4.0 international (CC BY-NC-SA 4.0):https://creativecommons.org/licenses/by-nc-sa/4.0/deed.uk

Authors who publish with this journal agree to the following terms:

  • Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
  • Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
  • Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).