A typical coal-fired power plant burns 320 metric tons of coalevery hour to generate 760 MW of electricity. 1 metric ton= 1000kg. The density of coal is 1500 kg/m^3 and its heat of combustionis 28 MJ/kg. Assume that all heat is transferred from the fuel tothe boiler and that all the work done in spinning the turbine istransformed into electrical energy.
What is the power plant's thermal efficiency?
What I know:
e= W/Qh
1 Watt = 1 Joule/sec
How I've tried to solve it:
320 metric tons * 1000 kg = 320000kg / 28 MJ/kg = 11428.6 MJ? I'mnot sure if I've done it to get the right units.
I know I need both the above number and the 760 MWatts to be inJoules per second.
When I divide the two resulting numbers I get 6.7% efficiency whichisn't correct. Can someone explain where I'm going wrong?
A typical coal-fired power plant burns 320 metric tons of coalevery hour to generate 760 MW of electricity. 1 metric ton= 1000kg. The density of coal is 1500 kg/m^3 and its heat of combustionis 28 MJ/kg. Assume that all heat is transferred from the fuel tothe boiler and that all the work done in spinning the turbine istransformed into electrical energy.
What is the power plant's thermal efficiency?
What I know:
e= W/Qh
1 Watt = 1 Joule/sec
How I've tried to solve it:
320 metric tons * 1000 kg = 320000kg / 28 MJ/kg = 11428.6 MJ? I'mnot sure if I've done it to get the right units.
I know I need both the above number and the 760 MWatts to be inJoules per second.
When I divide the two resulting numbers I get 6.7% efficiency whichisn't correct. Can someone explain where I'm going wrong?
