COSTS AND IRREVERSIBILITY IN HEAT EXCHANGERS / IRREVERSIBILIDADE E CUSTOS EM TROCADORES DE CALOR
AUTOR(ES)
CARLOS EDUARDO SANTOS MOREIRA DA COSTA
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
16/04/1986
RESUMO
From the second Law of Thermodynamics, the concepts of availability and irrervesibility are applied to heat exchangers. Equations relating the irreversibility to the heat-exchanger effectiveness are developed and applied to several cases. Relations between the decrease of irreversibility and operational costs are also established. Although it is commonly Said that the counterflow heat-exchanger is less irrerversible than the parallel flow heat-exchanger, the present work shows that this is not always true. A very simple criterion, based on the minimum loss of availability, was established. This criterion indicares, for the two types of heat exchangers, which one has the minimum irrerversibilty. It has been also proved that the heat-exchanger irreversibility has a point of maximum given by E iqual Cmax/ (Cmin more Cmax), where e is the heat-exchanger effectiveness. This value of e is na important parameter and it does not depend on the type of heat-exchanger under consideration.
ASSUNTO(S)
custo costs trocadores de calor heat exchangers
