An insulated steam turbine produces 25.0 MW of power. Steam enters the turbine at 10.0 MPa, 500°C, and with a velocity of 150 m/s, through a duct with a cross-sectional area of 0.01 m2. The steam exits with a velocity of 10 m/s, at a pressure of 100 kPa. Determine the exit temperature and, if applicable, the exit quality of the steam.
Given: P1 = 10.0 MPa; T1 = 500°C; V1 = 150 m/s; A1 = 0.01 m2; P2 = 100 kPa; V2 = 10 m/s; W?=25.0 MW=25,000 kW; Steam
Assume: Q? = 0 (insulated) Also, for a turbine, assume steady-state, steady-flow, single-inlet, single-outlet flow, with ?PE = 0
What will be an ideal response?
With these assumptions, the First Law for open systems reduces to
For steam, the following properties can be found:
v1 = 0.03281 m3/kg
h1 = 3375.06 kJ/kg
Then, m?=V1A1/v1 = 45.72 kg/s
Solving the First Law for h2:
h2=?25,000 kW45.72 kgs+(150ms)2?(10ms)22 (1000JkJ)+3375.06 kJ/kg = 2839.43 kJ/kg
With P2 and h2, the final state of the steam is T2 = 182°C, and the steam is superheated (no quality).
You might also like to view...
A block of tin with a volume of 0.002 m3 is cooled from 150°C to 80°C. If the density of tin is 7304 kg/m3 and its specific heat is 0.22 kJ/kg-K, determine the change in total internal energy of the tin during the process.
Given: Sn; V = 0.002 m3; T1 = 150°C; T2 = 80°C; ? = 7,304 kg/m3; c = 0.22 kJ/kg-K What will be an ideal response?
Most dairy cattle are registered
Indicate whether this statement is true or false.
Material prices are determined from suppliers who are required to quote prices to supply and deliver items that meet specifications.
Answer the following statement true (T) or false (F)
If R1 = 12 k? and R2 = 5 k? and they are wired in series across a 20 V source, what is VR1 and VR2?
A) VR1 = 0 V, VR2 = 20 V B) VR1 = 5.88 V, VR2 = 14.12 V C) VR1 = 10 V, VR2 = 10 V D) VR1 = 14.12 V, VR2 = 5.88 V