Thermodynamic analysis of the main devices for thermal energy upgrading

Exergetic analysis of a double stage LiBr–H2O thermal compressor cooled by air/water and driven by low grade heat

“…The physical exergetic balance applied to a fixed control volume is given by the following equation, according to Bejan et al [18]: (1) where Q is the heat transfer rate from or to the system, Wcv the mechanical power supplied by or to the system, ED the exergy destroyed because of the internal irreversibilities and e the physical component of the exergy transfer associated with the streams of matter. When the kinetic and potential energies are neglected, according to Bejan et al [18], the physical exergy 'e' can be evaluated as (2) The specific physical exergy of a flow of matter destroyed (eD) as a consequence of the specific entropy generated (sg) can also be evaluated applying the Goudy Stodola theorem as (3) where T0 is the reference temperature. In the present work T0 = 298 K, which is the comfort temperature.…”

“…However, there is little bibliography on the irreversibilities generated, which can only be evaluated on the basis of the second law. Some works analyzing this problem include those developed by Izquierdo et al [1], Adewusi and Zubair [14], Talbi and Agnew [15], Bisio [3], Meunier et al [16] and Chua et al [17].…”