Heat Engine Problem. Does the volume of a reservoir matter?

In summary, the conversation discusses two problems involving a heat engine operating between a tank of water and a river at a constant temperature of 10 degrees Celsius. The first problem asks for the maximum amount of work the engine can perform, while the second problem involves two tanks with the same volume. The speaker initially thought they could find the efficiency of the engine and use it to calculate the work, but the inclusion of volume in the first problem is causing confusion. Another person suggests considering the Carnot efficiency and reminds the speaker that the temperature is not constant in this calculation. The speaker is seeking help and mentions a homework help section.
  • #1
fazerland
1
0
Okay, I thought that I got these two easy problems but for some reason I'm making them hard.

The first problem reads like this.
"A heat engine operates between a tank containing 1*10^3 m^3 of water and a river at a constant temperature of 10 degrees Celcius. If the temperature of the tank is initially 100 degrees Celsius, what is the maximum amount of work that the heat engine can perform?"

At first I thought that I would just find the efficiency of the engine by using the temperatures after converting them to degrees Kelvin and then use it to find the work. But that information about the volume is bothering me. Did the author put it for some reason in there? If so what would I use it for exactly and how?

The second problem is pretty similar except there are two tanks and both of them have the same volume.

If anyone knows how to deal with these problems and could respond I would be so grateful.
 
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  • #2
The amount of energy in the system is the mass of the tank times the delta-T.

The problem may want you to be considering the carnot efficiency of a heat engine that uses a source and sink at those temperatures. Remember when you calculate that, the temperature is not constant...

Btw, we have a homework help section...
 
  • #3


I can say that the volume of a reservoir does matter in a heat engine problem. The volume of the reservoir is directly related to the amount of heat that can be stored in it. In the first problem, the larger volume of the tank allows for more heat to be stored, thus increasing the potential work that can be performed by the heat engine. This is because the efficiency of a heat engine is directly proportional to the temperature difference between the hot and cold reservoirs, and a larger volume results in a higher temperature difference.

In the second problem, both tanks have the same volume, so the amount of heat that can be stored in each tank is the same. This means that the potential work that can be performed by the heat engine will also be the same for each tank.

In conclusion, the volume of a reservoir does matter in a heat engine problem and should be considered when calculating the maximum amount of work that can be performed. It is important to take into account the amount of heat that can be stored in a reservoir in order to accurately determine the efficiency and potential work of a heat engine.
 

1. What is a heat engine problem?

The heat engine problem is a theoretical concept in thermodynamics that involves the transfer of heat energy into mechanical work. It is often used to analyze the efficiency and limitations of various heat engines.

2. How is the efficiency of a heat engine calculated?

The efficiency of a heat engine is calculated by dividing the work output by the heat input. This is known as the Carnot efficiency and is based on the assumption that the heat engine operates between two reservoirs at different temperatures.

3. What is the relationship between volume and efficiency in a heat engine?

The volume of a reservoir does not directly affect the efficiency of a heat engine. However, the size of the reservoirs can impact the heat transfer and therefore the efficiency of the engine. A larger volume may allow for a greater amount of heat to be transferred, potentially increasing efficiency.

4. How does the volume of a reservoir affect the power output of a heat engine?

The volume of a reservoir does not directly affect the power output of a heat engine. However, it can impact the amount of heat that can be transferred and therefore the maximum possible power output. A larger volume may allow for a greater transfer of heat and potentially increase the power output.

5. Can the volume of a reservoir be changed to improve the efficiency of a heat engine?

In theory, changing the volume of a reservoir may improve the efficiency of a heat engine. However, this would require other factors to remain constant, such as the temperature difference between the two reservoirs. In practical applications, changing the volume of a reservoir would not have a significant impact on the efficiency of a heat engine.

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