Consider a steam engine turbine in which steam enters at 10.45 MPa and 780 K with a flow rate of 38.79 kg/s. A portion of the steam is extracted from the turbine after partial expansion at three different locations. The external steam is then led to various heat exchangers. The mass flow rates and the temperatures and pressures at each extraction point are given below.
The remaining wet steam exits the turbine at 11.5 kPa with a quality (x) = 0.88. Determine the minimum pipe diameter required to restrict the maximum pipe inlet velocity to 50 m/s, the max extraction velocities each to 75 m/s, and the turbine outlet to 130 m/s.
Extraction m(kg/s) P(MPa) T(K)
1 4.343 3.054 620
2 4.345 0.332 482
3 2.871 0.136 x = 0.949