Thermodynamics issue with absorption heat pumps

Click For Summary
SUMMARY

This discussion centers on the thermodynamics of absorption heat pumps and their operation compared to standard heat pumps. It clarifies that while both types of heat pumps utilize energy to transfer heat, absorption heat pumps function as both heat engines and heat pumps, converting lower quality heat into higher quality energy. The conversation highlights the misconception regarding the application of a Carnot heat pump in conjunction with an absorption heat pump, emphasizing that the latter does not violate the second law of thermodynamics as it operates within the constraints of energy conversion efficiency.

PREREQUISITES
  • Understanding of thermodynamics principles
  • Familiarity with heat pump technology
  • Knowledge of the Carnot cycle and its implications
  • Concept of energy quality and entropy in thermodynamic systems
NEXT STEPS
  • Research the principles of absorption heat pumps and their applications
  • Study the Carnot cycle and its relevance to heat engines
  • Explore the second law of thermodynamics in detail
  • Investigate energy conversion efficiency in thermodynamic systems
USEFUL FOR

Students and professionals in mechanical engineering, thermodynamics researchers, and anyone interested in the efficiency and operation of heat pump systems.

striphe
Messages
125
Reaction score
1
I have been recently trying to advance my understanding of thermodynamics, but i have encountered a problem when it comes to absorption heat pumps and similar systems.

The standard heat pump requires an energy input, to move heat energy from one location to another. Most would consider absorption heat pumps no different as they use heat, a form of energy to operate. My consideration would say otherwise, as a standard heat pump uses, high quality energy to operate. Using high quality energy one can yield much more heat energy, using a heat pump.

From my understanding, a Carnot heat pump creates a heat gradient efficient enough for a Carnot heat heat engine to utilise and extract the exact amount of energy that was required to create the heat gradient. There is no reduction of entropy in this perfect system and so there is no second law violation.

If i decided to use a Carnot heat pump to operate an absorption heat pump, the heat added by the Carnot heat pump, is less than the heat expelled by the absorption heat pump. Using a Carnot heat engine to make use of the gradient, I would expect that the engine would produce surplus high quality energy, in violation of the second law.

So where have a gone wrong in my understanding in this case?
 
Science news on Phys.org
After more consideration I understand where my mistake has come from.

An absorption heat pump is not purely a heat pump, it is a heat engine and a heat pump. The heat used is converted to a higher quality energy which is utilised by the heat pump.

however I still have problems with another heat pump concept, but i will do another post for that one.
 
Last edited:

Similar threads

  • · Replies 19 ·
Replies
19
Views
5K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 20 ·
Replies
20
Views
3K