Direction: The inlet and the outlet conditions of steam for an adiabatic steam turbine are as indicated in the notations are as usually followed.
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If mass flow rate of steam through the turbine is 20 kg/s, the power output of the turbine (in MW) is
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- 12.157
- 12.941
- 168.001
- 168.785
Correct Option: A
SFEE h1 + z1g + | + Q = h2 + z2g + | + W | ||
2 | 2 |
For adiabatic process, Q = 0
∴ h2 + z1g + | = h2 + z2g + | + W | ||
2 | 2 |
Or 3200 × 10³ + 10 × 9.81 + | |
2 |
= 2600 × 10³ + 6 × 9.81 + | + W | |
2 |
⇒ W = 600 × 10³ + 39.24 + | + W | |
2 |
= 607839.24 × 20 J/s = 12.156 MW
Applying S.F.E.E
w1 | h1 + | + gz1 | + | w2 | h2 + | + gz2 | + | ||||||||
2 | dτ | 2 | dτ |
Here, w1 = mass flow rate
= 0 for insulated turbine | |
dτ |
∴ 20 | 3200 + | × 9.81 × 10 | |||
2 × 10³ |
= 20 | 2600 + | + | + | |||||
2 × 10³ | 10³ | dτ |
Or | = 20 | (3200 - 2600) + | - | + | |||||||||
dτ | 10³ | 2 | 2 | 10³ |
= 20 × {600 + 7.8 + 0.03924}
= 20 × 607.83924 kW
= 12156.7848 kW ≃ 12.157MW