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

In summary, the conversation is about a problem involving a coal-burning power plant and its efficiency. The question is how much heat is discarded to the environment and how much heat is needed to be supplied by burning coal to operate a steam turbine with a power output of 491 MW. The relevant equation is e = W/Qh and the main difficulty is understanding how to solve the problem.
  • #1
planke
5
0

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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  • #2
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)
 
  • #3
I think this problem should be really straightforward, but I am still having trouble understanding how to solve it.
 
  • #4
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 ?
 

What is power output?

Power output is the rate at which energy is transferred or converted from one form to another. It is typically measured in units of watts (W) or horsepower (hp).

How is power output related to thermodynamics?

Power output is closely related to the laws of thermodynamics, specifically the first and second laws. The first law states that energy cannot be created or destroyed, only transferred or converted, while the second law states that energy tends to flow from higher to lower temperatures. These laws govern the efficiency of power output in various systems.

What factors affect power output?

Several factors can affect power output, including the type of energy source, the efficiency of the conversion process, and the size and design of the system. Other factors such as temperature, pressure, and heat transfer also play a role in determining power output.

How is power output measured?

Power output can be measured using various techniques, depending on the type of system. In general, it involves measuring the amount of energy transferred or converted over a specific period of time. This can be done using instruments such as wattmeters, dynamometers, or calorimeters.

What are some examples of power output in everyday life?

Power output is present in many aspects of our daily lives. Some common examples include the power output of a car engine, the electricity generated by a power plant, or the power output of the human body during physical activity. Other examples include the power output of electronic devices, such as computers or smartphones, and the power output of renewable energy sources, such as solar panels or wind turbines.

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