Consider a steam turbine in which steam enters at 1500 psia and 900 F with a flow

Question:

Consider a steam turbine in which steam enters at 1500 psia and 900 F with a flow rate of 85.4 lbm/s. As shown in the sketch for Problem 3.55, a portion of the steam is extracted from the turbine after partial expansion at different locations.

The extracted steam is then led to various heat exchangers. The mass flow rates and the temperatures and pressures at each extraction point are given in the following table.

The remaining wet steam exits the turbine at 2.0 psia with a quality of 0.8564.

(i) Determine the minimum pipe diameters in inches required to restrict the maximum inlet velocity to 160 ft/s, the maximum extraction velocities each to 240 ft/s, and the turbine outlet velocity to 350 ft/s.

(ii) Sketch a temperature specific-volume plot showing the various points and their associated isobars.

Problem 3.55

Consider a steam turbine in which steam enters at 10.0 MPa and 780 K with a flow rate of 39.0 kg/s. As shown in the sketch, a portion of the steam is extracted from the turbine after partial expansion at three different locations. The extracted steam is then led to various heat exchangers. The mass flow rates and the temperatures and pressures at each point are given in the following table:

The remaining wet steam exits the turbine at 12.0 kPa with a quality of 0.88.

(i) Determine the minimum pipe diameters required to restrict the maximum inlet velocity to 40 m/s, the maximum extraction velocities each to 65 m/s, and the turbine outlet velocity to 120 m/s. Use the tables in Appendix B to obtain any necessary steam properties.

(ii) Sketch a temperature–specific-volume plot showing the various state points and their associated isobars.