DEVELOPMENT OF A NEW THERMODYNAMIC CHART FOR ISENTROPIC EXPANSION OF CONDENSING STEAM FLOW

A new thermodynamic chart for isentropic expansion of compressible steam flow is developed. The steam is assumed to obey local equilibrium thermodynamic model, where condensation onsets as soon as the saturation line is crossed at ``c.o.''. Above the ``c.o.'', the stagnation properties reflect those at inflow. However, beyond the ``c.o.'', the transfer of latent heat toward the vapor portion of the two-phase mixture, rises its stagnation temperature. A non-dimensional function ``zeta'', is defined, which represents the increase in vapor stagnation temperature. The vapor is assumed to be an actual gas obeying the ``Lee-Kesler'' EOS.

Keywords:

Analytical Solution of Steam , Equilibrium Thermodynamics , Compressible Steam Flow