Heat Engines and Work: Combining Two Engines

In summary: OfFact: A carnot refrigerator is a machine which moves heat from the cold reservoir to the hot reservoir. It is not a refrigerator.
  • #1
hockeybro12
14
0

Homework Statement



There is a heat engine with Th on top at 100 J pointing down, Tc on bottom pointing down with 50 J and the work output is 50 J pointing right out of the engine. (ENGINE 1)

a) Draw the diagram for a carnot refrigerator which draws 100 J of heat from the hot reservoir (Th = 450 K and Tc = 270 K). we have to find the work output and the heat dumped to the cold reservoir. Using this information, make a new heat engine. (ENGINE 2)

b) what is the engine that results when you combine the two engines. (#1 and 2)

c) what is interesting about this combination?


Homework Equations



efficiency = 1 - QL/QH
ideal efficiency = 1 - TL/TH


The Attempt at a Solution



A carnot engine is basically one in which everything is perfect. This can never exist in reality. In the refrigerator heat engine, the arrow for TH should point up, the arrow for TL(TC) should point up and the energy should point in. However, I am not able to figure out the values for them besides the fact that TH is 100 J since that is given. Without this information, I can't do part B and C
 
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  • #2
Why does no one know this? Please ask me if you are having trouble understanding the problem.

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  • #3
hockeybro12 said:

Homework Statement



There is a heat engine with Th on top at 100 J pointing down, Tc on bottom pointing down with 50 J and the work output is 50 J pointing right out of the engine. (ENGINE 1)

a) Draw the diagram for a carnot refrigerator which draws 100 J of heat from the hot reservoir (Th = 450 K and Tc = 270 K). we have to find the work output and the heat dumped to the cold reservoir. Using this information, make a new heat engine. (ENGINE 2)
A refrigerator moves heat from the cold reservoir to the hot reservoir. What you are describing is a heat engine, not a refrigerator.

The reason no one has responded so far may be because the question makes no sense. Please give us the exact wording.

AM
 

Related to Heat Engines and Work: Combining Two Engines

1. What is a heat engine?

A heat engine is a device that converts thermal energy (heat) into mechanical energy (work). It follows the principles of the first and second laws of thermodynamics, and operates in a cycle to produce useful work.

2. How does a heat engine work?

A heat engine works by taking in heat from a high-temperature source, using this heat to do work, and then releasing the remaining heat to a low-temperature sink. This process is known as a thermodynamic cycle and is repeated continuously to produce a continuous output of work.

3. What is the efficiency of a heat engine?

The efficiency of a heat engine is the ratio of the amount of work output to the amount of heat input. It is given by the formula efficiency = work output / heat input. The maximum possible efficiency for a heat engine is determined by the Carnot cycle and is dependent on the temperatures of the heat source and sink.

4. What types of heat engines are there?

There are two main types of heat engines - external combustion engines and internal combustion engines. External combustion engines, such as steam engines, use an external heat source to generate steam and produce work. Internal combustion engines, such as car engines, use the combustion of fuel within the engine to produce work.

5. What is the difference between heat and work in a heat engine?

In a heat engine, heat is the energy transferred from a high-temperature source to a low-temperature sink. This heat is used to do work, which is the energy transferred to an object to move it a certain distance. While heat is a form of energy transfer, work is the actual energy being used to perform a task or produce a desired effect.

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