Wednesday, October 22, 2008

TE 303 - HW #5, P4 - Analysis of a Two-Stage, Adiabatic Turbine - 12 pts

A well-insulated two-stage turbine operating at steady-state is shown in the diagram. Steam enters at 3 MPa and 400oC with a volumetric flow rate of 85 m3/min. Some steam is extracted from the turbine at a pressure of 0.5 MPa and a temperature of 180oC. The rest expands to a pressure of 6 kPa and a quality of 90%. The total power developed by the turbine is 11,400 kW. Changes in kinetic and potential energies are negligible. Determine:

a.) The mass flow rate of the steam at each of the two exits.

b.) The diameter in meters of the duct through which the 0.5 MPa steam is extracted if the velocity there is 20 m/s.



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1 comment:

Anonymous said...

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HINTS:
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* Be sure to check out the comments from Dr. B's course!

* The key to this problem is the splitter. It is just like a tee in a pipe. So, the properties of streams 2,3, and 4 are the same.

* Think about what you define as the "system" (or control volume) in this problem.

* You will need to use the steam tables to get some of your values. Be sure to think about the phase of your materials at the appropriate places.

* You will need to write a mass balance equation to find the mass flow rate at 4.

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ANSWERS:
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mass flow rate at 4: 3.151 kg/s

mass flow rate at 5: 11.105 kg/s

D4 = 28.47 cm