ME 3320: Thermodynamics II Handout #10 Homework #10...
Transcript of ME 3320: Thermodynamics II Handout #10 Homework #10...
-
ME 3320: Thermodynamics II Handout #10
Homework #10: Problems 10-14, 10-34,10-46,10-70E,10-84
-
10-44 The closed feedwater heater of a regenerative Rankine cycle is to heat 7000 kPa feedwater from 260°C to a saturated liquid exiting the mixing chamber. The turbine supplies bleed
steam at 6000 kPa and 325°C to this unit. This steam is condensed to a saturated liquid before entering pump 2. Calculate
the amount of bleed steam required to heat 1 kg of feedwater in
this unit.
-
10-46 Repeat Prob. 10-45 by replacing the open feedwater heater with a closed feedwater heater. Assume that the feedwater
leaves the mixing chamber at the condensation temperature of the
extracted steam and that the extracted steam leaves the heater as a
saturated liquid and is pumped to the line carrying the feedwater.
-
10-69 Steam enters the turbine of a cogeneration plant at 4 MPa
and 500°C. One-fourth of the steam is extracted from the turbine
at 1200-kPa pressure for process heating. The remaining steam
continues to expand to 10 kPa. The extracted steam is then
condensed and mixed with feedwater at constant pressure and the
mixture is pumped to the boiler pressure of 4 MPa. The mass
flow rate of steam through the boiler is 55 kg/s. Disregarding any
pressure drops or the heat losses in the piping, and assuming the
turbine and the pump to be isentropic, determine the net power
produced and the utilization factor of the plant.