Optimal paths for minimizing lost available work during heat transfer processes with a generalized heat transfer law

AUTOR(ES)
FONTE

Brazilian Journal of Physics

DATA DE PUBLICAÇÃO

2009-03

RESUMO

A common of finite-time heat transfer processes between high- and low-temperature sides with a generalized heat transfer law [q ∝ (Δ(Tn ))m] are studied in this paper. The optimal heating and cooling configurations for minimizing lost available work are derived for the fixed initial and final temperatures of the working fluid of the system (low-temperature side). Optimal paths are compared with the common strategies of constant heat flux, constant source (reservoir) temperature and the minimum entropy generation operation by numerical examples. The condition corresponding to the minimum lost available work strategy is that corresponding to a constant rate of lost available work, not only valid for Newton's heat transfer law [q ∝ ΔT] but also valid for the generalized convective heat transfer law [q ∝ (ΔT)m ]. The obtained results are more general and can provide some theoretical guidelines for the designs and operations of practical heat exchangers.

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