The mass rate of flow into a steam turbine is 4500 kg/h and the heat transfer from the turbine is 8.8 kW. The following data are known for the steam entering and leaving the turbine.
Pressure 20 bar 1 bar
Temperature 420 C
Velocity 60 m/s 150 m/s
Elevation above datum 5 m 3 m
Determine the output power of the turbine.© BrainMass Inc. brainmass.com December 24, 2021, 7:46 pm ad1c9bdddf
SOLUTION This solution is FREE courtesy of BrainMass!
Please see the attachment for a solution.
The useful power can be determined by applying the equation of energy:
steam (water) mass flow rate (kg/s)
inlet specific static enthalpy (and similarly for the outlet) (kJ/kg)
inlet, respectively outlet velocities (m/s)
elevations above datum (m)
g = gravity acceleration (g = 9.8 m/s2)
output (useful) power of turbine (kW)
heat transfer rate from turbine (kW)
Assuming an isentropic process between inlet and outlet, the following formula applies:
k = adiabatic exponent (for superheated steam, k = 1.3)
T1 = 420C = 420 + 273 = 693 K
specific heat of steam at constant pressure (kJ/kg.K)
Assuming a constant average value of specific heat during the process, we can use the formula:
R = steam gas constant, R = 461.9 J/kg.K
By substituting in (2), one yields: