PROBLEM #4: A back pressure steam turbine of 100,000 kW serves as a prime mover in a cogeneration system. The boiler adm
Posted: Sun Jul 10, 2022 11:41 am
PROBLEM #4: A back pressure steam turbine of 100,000 kW serves as a prime mover in a cogeneration system. The boiler admits the return water at a temperature of 66°C and produces the steam at 6.5 MPa and 455°C. Steam then enters a back pressure turbine and expands to the pressure of the process, which is 0.52 MPa. Assuming a boiler efficiency of 80% and neglecting the effect of pumping and the pressure drops at various locations, what is the incremental heat rate for electric? The following enthalpies have been found: Turbine Entrance = 3306.8 kJ/kg Turbine Exit = 2700.8 kJ/kg Boiler Entrance = 276.23 kJ/kg Boiler Exit = 3306.8 kJ/kg Choices: A. 22,504.23 kJ/kg B. 52,244.32 kJ/kg C. 12,435.72 kJ/kg D. 32,234.82 kJ/kg