Thermodynamics Problem Clarification

  • Thread starter Thread starter neelakash
  • Start date Start date
  • Tags Tags
    Thermodynamics
Click For Summary
SUMMARY

The discussion clarifies the relationship between the Clausius and Kelvin-Planck statements of the second law of thermodynamics. The Clausius statement asserts that heat cannot spontaneously flow from a colder body to a hotter body, while the Kelvin-Planck statement indicates that no cyclic process can produce net work from a single thermal reservoir. The proposed scenario demonstrates that if the Clausius statement were false, it would allow for a heat engine to produce net work while interacting with only one thermal reservoir, thereby violating the Kelvin-Planck statement. This logical contradiction underscores the interdependence of these two fundamental thermodynamic principles.

PREREQUISITES
  • Understanding of the Clausius statement of the second law of thermodynamics
  • Familiarity with the Kelvin-Planck statement of the second law of thermodynamics
  • Basic knowledge of heat engines and heat pumps
  • Concept of thermal energy reservoirs
NEXT STEPS
  • Study the implications of the Clausius statement in thermodynamic cycles
  • Explore the derivation and applications of the Kelvin-Planck statement
  • Investigate real-world examples of heat engines and heat pumps
  • Learn about the Carnot cycle and its significance in thermodynamics
USEFUL FOR

Students of thermodynamics, physics educators, and professionals in engineering fields focused on energy systems and heat transfer.

neelakash
Messages
491
Reaction score
1

Homework Statement



Show that if the Clausius statement of the 2nd law were not true a violation of Kelvin Planck statement would be possible.

Homework Equations





The Attempt at a Solution



My attempts: Please check it and confirm if I am correct.

Clausius Statement - States that it is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a lower temperature body to a higher temperature body.

Kelvin-Planck Statement - States that no system can produce a net amount of work while operating in a cycle and exchanging heat with a single thermal energy reservoir.

let there be a heat pump HP which takes Q2 heat from TL and delivers it to TH(Clausius statement)
Let us consider another Heat engine that takes heat a source TH and delivers a wet work out put W_net and rejects Q2 heat to sink.

Now we can remove T(LOW), and feed the Q2 heat from HE to HP

Now considering HE+HP as a single heat engine, we see it produces a net work Wnet while exchanging heat with a single energy reservior(KelvinP statement)
 
Physics news on Phys.org

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 7 ·
Replies
7
Views
16K
  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K