How Much Heat Does a Power Plant Transfer to a River Each Second?

[Runaway]

Homework Statement

A power plant has a power output of 1246 MW and operates with an efficiency of 34.8 percent. Excess energy is carried away as heat from the plant to a nearby river that has a flow rate of 1.4 * 10^6 kg/s.
How much energy is transferred as heat to the river each second.
Answer in J/s

Homework Equations

change in entropy = Q/T

The Attempt at a Solution

I'm not sure how to set this one up, is 1246 the total output ie the fuel being consumed expels that much and 34.8 percent of that goes to making power, or is 1246 what goes to making power, and the other 65.2 percent goes to the river, and where does the rate of flow of the river come into play?

 

[supratim1]

1246 must be 34.8% of total fuel power. the flow rate of river is associated with how much heat 1 kg of water absorbs in 1 second. but for that we need other data.

 

[kreil]

I interpreted it as: The power plant has a power output of 1246 MW, which represents 34.8% of the energy put in.

So if the total energy is x, then:

[tex] \frac{1246}{x} = \frac{34.8}{100}[/tex]

And so the amount of energy being released as heat is H = x - 1246.

The flowrate of the river affects how quickly the heat released by the power plant gets absorbed. The quicker the water flow, the quicker we expect the heat to get absorbed. If you use the flowrate of the river (kg/s) along with the specific heat of the water (J/kg*K) and the temperature (K), you will get an answer in J/s.