In this task, you should base your work on a Rankine cycle with water/steam as the working medium. State 1 (into pump/out of condenser): saturated liquid at 30 kPah1=hf (30 kPa) = 289.27 kJ/kg State 2 (out of pump/into boiler): subcooled liquid at 5 MPah2 = 294.35 kJ/kg State 3 (out of boiler/into turbine): superheated steam at 5 MPa, 600°Ch3 = h(5 MPa, 600°C) = 3666.9 kJ/kg State 4 (out of turbine/into condenser): saturated steam at 30 kPah4 = hg (30 kPa) = 2624.6 kJ/kg The heat added in the boiler was calculated to be Qin,boiler = 16863 kW. The mass flow rate of the working fluid remains 5 kg/s. The pump in this cycle is isentropic (pump power is 25.4 kW), while the turbine is non-isentropic. The temperature of the heat source for the boiler is 1000°C (constant). The condenser transfers waste heat to the surroundings at 15°C and 100 kPa. a) Calculate the power output from the steam turbine (in kW or MW).b) Calculate the isentropic efficiency of the turbine.c) Calculate the second-law efficiency of the turbine.d) Calculate the exergy destruction rate in the boiler in kW or MW.e) Calculate the second-law efficiency of the entire system.f) Draw a T-s diagram of the cycle. Show the states and the process curve relative to the saturation curve. Also, draw lines for constant pressure passing through the four relevant states.
In this task, you should base your work on a Rankine cycle with water/steam as the working medium.
State 1 (into pump/out of condenser): saturated liquid at 30 kPa
h1=hf (30 kPa) = 289.27 kJ/kg
State 2 (out of pump/into boiler): subcooled liquid at 5 MPa
h2 = 294.35 kJ/kg
State 3 (out of boiler/into turbine): superheated steam at 5 MPa, 600°C
h3 = h(5 MPa, 600°C) = 3666.9 kJ/kg
State 4 (out of turbine/into condenser): saturated steam at 30 kPa
h4 = hg (30 kPa) = 2624.6 kJ/kg
The heat added in the boiler was calculated to be Qin,boiler = 16863 kW. The mass flow rate of the working fluid remains 5 kg/s. The pump in this cycle is isentropic (pump power is 25.4 kW), while the turbine is non-isentropic. The temperature of the heat source for the boiler is 1000°C (constant). The condenser transfers waste heat to the surroundings at 15°C and 100 kPa.
a) Calculate the power output from the steam turbine (in kW or MW).
b) Calculate the isentropic efficiency of the turbine.
c) Calculate the second-law efficiency of the turbine.
d) Calculate the exergy destruction rate in the boiler in kW or MW.
e) Calculate the second-law efficiency of the entire system.
f) Draw a T-s diagram of the cycle. Show the states and the process curve relative to the saturation curve. Also, draw lines for constant pressure passing through the four relevant states.
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