Heat Engines and Work: Combining Two Engines

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SUMMARY

The discussion centers on the combination of two heat engines: ENGINE 1, which outputs 50 J of work from a hot reservoir (Th) at 100 J and a cold reservoir (Tc) at 50 J, and ENGINE 2, a Carnot refrigerator that draws 100 J of heat from a hot reservoir at 450 K and a cold reservoir at 270 K. The efficiency equations discussed are efficiency = 1 - QL/QH and ideal efficiency = 1 - TL/TH. The participants express confusion regarding the values needed for ENGINE 2 and the implications of combining both engines.

PREREQUISITES
  • Understanding of thermodynamics, specifically heat engines and refrigerators.
  • Familiarity with Carnot cycle principles and efficiency calculations.
  • Knowledge of heat transfer concepts and energy conservation.
  • Ability to interpret and create thermodynamic diagrams.
NEXT STEPS
  • Study the Carnot cycle and its implications for real-world engines.
  • Learn about the calculations for work output in thermodynamic systems.
  • Research the concept of combining heat engines and refrigerators for efficiency improvements.
  • Explore advanced thermodynamic efficiency equations and their applications.
USEFUL FOR

Students of thermodynamics, engineers working with heat engines, and anyone interested in the principles of energy conversion and efficiency in thermal systems.

hockeybro12
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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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Why does no one know this? Please ask me if you are having trouble understanding the problem.

Bump
 
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
 

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