Exergy Analysis of Organic Rankine Cycle with Internal Heat Exchanger

In recent years Organic Rankine Cycle (ORC) has become a field of intense research and appears a promising technology for conversion of heat into useful work or electricity. In this work thermodynamic performance of ORC with internal heat exchanger is comparatively assessed for various working fluids based on the second law of thermodynamics. Special attention is paid to the effect of turbine inlet pressure on the exergy destructions (anergies) at various system components and the exergy efficiency of system. Results show that for a given source the component at which the greatest anergy occurs differs with working fluid. As turbine inlet pressure increases, exergy efficiency increases for working fluid such as ammonia or R22, but decreases for working fluid with low critical pressure such as iso-pentane or n-pentane.