What is the Power Output and Efficiency of a Coal-Burning Power Plant?

AI Thread Summary
The discussion focuses on calculating the heat discarded and the heat supplied by a coal-burning power plant with a power output of 491 MW and a thermal efficiency of 39.0%. Participants express uncertainty about how to approach the problem, particularly in applying thermodynamic equations related to power and efficiency. The relevant equation for efficiency is highlighted as η = W/Qh, prompting questions about the definition of Qh. The conversation emphasizes the need for clarity in understanding thermodynamic principles to solve the problem effectively. Overall, the thread illustrates the challenges faced in applying theoretical concepts to practical calculations in thermodynamics.
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Homework Statement



At a coal-burning power plant a steam turbine is operated with a power output of 491 MW. The thermal efficiency of the power plant is 39.0%.
(a) At what rate is heat discarded to the environment by this power plant?
______ GW

(b) At what rate must heat be supplied to the power plant by burning coal?
______ GW



Homework Equations


e = W/Qh = Qh-Qc / Qh


The Attempt at a Solution


I don't know how to approach this problem. Is there some equation for power to use for thermodynamics?

Thanks!
 
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planke said:

The Attempt at a Solution


I don't know how to approach this problem. Is there some equation for power to use for thermodynamics?

Thanks!

Start with the definition of efficiency η.

Remember power is nothing but the rate of change of energy. (1 W = 1 J/s)
 
I think this problem should be really straightforward, but I am still having trouble understanding how to solve it.
 
planke said:
I think this problem should be really straightforward, but I am still having trouble understanding how to solve it.

In your relevant equations you posted

e=W/Qh

So what is Qh ?
 

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