Efficiencies and Irreversible Losses

Irreversible processes are accompanied by entropy generation, \(\dot{S}_{gen} > 0,\) e.g., due to friction, heat transfer over finite temperature differences, mixing, or other uncontrolled processes. In the discussion of work losses for closed and open systems we found that irreversibilities reduce the efficiency of energy conversion devices. In this chapter, we study work loss to irreversibility in greater detail. The arguments used are similar to “exergy accounting”, which is briefly discussed.