In this paper we analyse in depth the Lost Work in an irreversible process (i.e. IRREV REV Lost ) W =W -W . This quantity is also called ‘degraded energy’ or ‘Energy unavailable to do work’. Usually in textbooks one can find the relation Lost U W º TDS . Here we show that Lost W can be expressed in terms of internal and external Entropy production, int p and ext p , quantities which enable to write down in a simple way the Clausius inequality. We will show that º + B A Endo ext ext B A Lost sys T T W dp d p int , where sys T is the temperature of the system during the corresponding quasi-static process and ext T is the temperature of the external heat source during the related Endo-reversible process. Endo ext dp is the infinitesimal entropy production in each infinitesimal step of such Endoreversible process. Examples are given for elementary processes.

Entropy production and lost work for some irreversible processes

DI LIBERTO, FRANCESCO
2007

Abstract

In this paper we analyse in depth the Lost Work in an irreversible process (i.e. IRREV REV Lost ) W =W -W . This quantity is also called ‘degraded energy’ or ‘Energy unavailable to do work’. Usually in textbooks one can find the relation Lost U W º TDS . Here we show that Lost W can be expressed in terms of internal and external Entropy production, int p and ext p , quantities which enable to write down in a simple way the Clausius inequality. We will show that º + B A Endo ext ext B A Lost sys T T W dp d p int , where sys T is the temperature of the system during the corresponding quasi-static process and ext T is the temperature of the external heat source during the related Endo-reversible process. Endo ext dp is the infinitesimal entropy production in each infinitesimal step of such Endoreversible process. Examples are given for elementary processes.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11588/102876
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