Superheated steam at 20 bar and 380?C enters a steam turbine with a velocity of

Question

Superheated steam at 20 bar and 380?C enters a steam turbine with a velocity of 60 m/s. The
pressure, quality and velocity of the water at the discharge section of the turbine are 0.75 bar,
0.95, and 200 m/s, respectively. The entrance section of the turbine has an area of 0.025 m
2 and it is 3 m above the exit section. The rate of heat loss from the turbine casing to the surroundings
is 8.5 kW. Calculate (a) the mass flow rate (kg/s) of the steam, and (b) the power output (MW)
of the turbine.

Explanation / Answer

the amount of gas entering per sec = 60*0.025 =1.5m^3 so the no of moles entering per sec according to PV=nRT is n= PV/RT = 559.58 moles hence the mass flow rate =559.8*18 = 100.72KG/s as 18 = molecular weight of 1 mole steam A>100.72Kg/s the power out put +loss of heat energy=potential energy due to 3 m height difference + 2*(380-0.95)*100.72 as 2 Kj is the sp heat of steam hence the out put =76358.772-8.5 =76350.2KW cheers :)

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.