Calculating Efficiency and Thermal Source Rate in a Steam-Electric Power Plant

In summary, the steam-electric power plant has an efficiency of 22.42% and a rate of energy delivery of 4013 MW. The surplus heat is exhausted into a river, causing a change in temperature of 1.35 oC. The rate of the thermal source is equivalent to the total input power of 4013 MW.
  • #1
rlc
128
1

Homework Statement


A steam-electric power plant delivers 900 MW of electric power. The surplus heat is exhausted into a river with a flow of 5.51×105 kg/s, causing a change in temperature of 1.35 oC.
What is the efficiency of the power plant?
What is the rate of the thermal source?

Homework Equations


Q=cm(delta T)
c=4.186 J/g*Celsius

The Attempt at a Solution


I know how to answer the first question already:
Q=(4186 J/kg C)(5.51E5 kg/s)(1.35 C)
Q=3113756100 J/s (J/s=Watt)
Convert from Watt to Megawatt --> 3113.76 MW
900+3113.76=4013.76=Total output
900/total output=0.2242=22.42 %

I don't know how to calculate the rate of the thermal source.
What am I missing?
 
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  • #2
Input power = 4013,76 MW = 900 MW + 3113,76 MW

That's the input, i.e., the power delivered by the high-temp source to the machine, and not the output.

The original, high-temp power (4013,76 MW) is transformed by the machine in 900 MW of electricity and 3113,76 of 'rejected', low-temp power.

The calculation of the efficiency is right: 900/Total input
 
  • #3
That makes sense, but how do you calculate the rate of the thermal source?
 
  • #4
rlc said:
That makes sense, but how do you calculate the rate of the thermal source?

I don't know what you mean by that. I suspect that it may be the rate of energy delivery of the thermal source. That's the power.
 
  • #5
Yeah, the question was asked in a weird way.
I tried 4013 MW and it said that that is correct for the rate.

Thank you for helping me!
 

FAQ: Calculating Efficiency and Thermal Source Rate in a Steam-Electric Power Plant

What is an Efficiency PowerPlant?

An Efficiency PowerPlant is a type of power plant that is designed to produce energy with the highest possible efficiency. This means that it can convert a higher percentage of the input energy into usable output energy.

How does an Efficiency PowerPlant work?

An Efficiency PowerPlant typically uses advanced technology and engineering to optimize the conversion of energy. This can include using combined cycle systems, waste heat recovery, and other methods to improve efficiency.

What are the benefits of using an Efficiency PowerPlant?

Using an Efficiency PowerPlant can result in significant cost savings, as it requires less fuel to produce the same amount of energy compared to traditional power plants. It also reduces emissions and helps to conserve natural resources.

Are there any downsides to using an Efficiency PowerPlant?

The main downside of an Efficiency PowerPlant is the initial cost of building and implementing the advanced technology. It may also require more maintenance and specialized knowledge to operate compared to traditional power plants.

Can an Efficiency PowerPlant be used for all types of energy production?

An Efficiency PowerPlant can be used for a variety of energy sources, including fossil fuels, nuclear, and renewable energy. However, the efficiency gains may vary depending on the specific energy source and technology used.

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