Boiler-turbine, conservation of energy, actual vs. Carnot efficiency
The figure below despicts schematically a power plant cycle containing
a turbine which is fed from a boiler with
superheated steam and exhausts saturated steam at lower pressure into
a condensor. Due to poor insulation the turbine looses heat at a
rate of 1000 kJ/s.
- At which rate (kg/s) must steam be provided to the turbine in order
for the turbine to have a power output of 10 MW ?
- At what rate [kJ/s] must heat be transferred to the water
inside the boiler ?
- What is the efficiency (benefits/costs) of the turbine if the costs
consists of the heat transferred inside the boiler ? You may neglect
the work needed by the pump.
- What would the efficiency of a Carnot cycle be if it were to operate
between the temperature of the superheated steam entering the turbine
and the temperature of the exiting saturated steam ?