A steam turbine is supplied with steam at 8000 F and 600 psi

A steam turbine is supplied with steam at 8000 F and 600 psia. The stem is expanded adiabatically to saturated vapor at 20 psia. If the properties of steam at initial and final states are as given here, determine the work output of the turbine per pound of steam.

600 psia and 800 F 20 psia (saturated vapor)

h = 1408.3 Btu/lbm h = 1156.3 Btu/lbm

v = 1.1892ft3 /lbm v 20.087 ft3 /lbm

u = 1276.2 Btu/lbm u = 1081.94 Btu/lbm

Solution

Work output of turbine is,

W=h₁-h₂

   _{=1408.3-1156.3}

_{=252 Btu/lbm}