Carnot Heat Engine to Carnot Heat Pump

In summary, the conversation discusses the use of a carnot engine and heat pump with different temperature reservoirs to produce work. The ratio of heat absorbed by the heat engine to the heat absorbed by the heat pump is not applicable due to an incorrect temperature scale being used.
  • #1
keith river
15
0
We have a carnot engine with Th = 800 degrees Celsius, and Tc = 50 degrees Celsius.
This produces a work which is drives a carnot heat pump which has heat reservoirs at Th' = 50 degrees celsius and Tc' = 0 degress Celsius.
What is the ratio of heat absorbed by the Heat Engine to the heat absorbed by the heat pump.

I know the ratio from Qh/Qc for the heat engine would be Th/Tc but when I was planning on doing the same for a heat pump (Qh'/Qc') but It doesn't work out as the ratio would be infinite (divides by 0)
I was going to rearrange for Qh/Qc' as these are the heats absorbed by the heat engine and pump respectfully but this also would be infinite.
 
Physics news on Phys.org
  • #2
keith river said:
We have a carnot engine with Th = 800 degrees Celsius, and Tc = 50 degrees Celsius.
This produces a work which is drives a carnot heat pump which has heat reservoirs at Th' = 50 degrees celsius and Tc' = 0 degress Celsius.
What is the ratio of heat absorbed by the Heat Engine to the heat absorbed by the heat pump.

I know the ratio from Qh/Qc for the heat engine would be Th/Tc but when I was planning on doing the same for a heat pump (Qh'/Qc') but It doesn't work out as the ratio would be infinite (divides by 0)
I was going to rearrange for Qh/Qc' as these are the heats absorbed by the heat engine and pump respectfully but this also would be infinite.
You are using the wrong scale for temperature.

AM
 
  • #3
Thanks AM
I can't believe I never noticed that before. Such a simple problem.
 

1. How does a Carnot heat engine work?

A Carnot heat engine operates on the principle of converting thermal energy into mechanical work. It does this by utilizing a cycle of four processes - isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression - to transfer heat from a hot reservoir to a cold reservoir. This process is governed by the laws of thermodynamics and results in the production of work.

2. What is the efficiency of a Carnot heat engine?

The efficiency of a Carnot heat engine is given by the Carnot efficiency formula, which is the ratio of the temperature difference between the hot and cold reservoirs to the temperature of the hot reservoir. This means that the efficiency of a Carnot heat engine can never be 100%, as some energy will always be lost in the form of heat.

3. What is the difference between a Carnot heat engine and a Carnot heat pump?

A Carnot heat engine and a Carnot heat pump both operate on the same principle, but the direction of energy transfer is different. While a Carnot heat engine converts thermal energy into mechanical work, a Carnot heat pump uses mechanical work to transfer heat from a cold reservoir to a hot reservoir. In other words, a Carnot heat pump is the reverse of a Carnot heat engine.

4. How does a Carnot heat pump contribute to energy efficiency?

A Carnot heat pump is considered to be highly efficient because it utilizes a reversible process that results in minimal energy loss. This means that it can provide more cooling or heating for the same amount of energy compared to other types of heat pumps. It also does not rely on any harmful refrigerants, making it an environmentally friendly option for heating and cooling.

5. What are some real-world applications of Carnot heat pumps?

Carnot heat pumps are commonly used in refrigerators, air conditioners, and heat pumps for heating and cooling buildings. They are also used in industrial processes, such as food and beverage production and chemical production, to maintain specific temperatures. Additionally, Carnot heat pumps are being explored as a potential solution for renewable energy storage and utilization.

Similar threads

  • Advanced Physics Homework Help
Replies
5
Views
1K
Replies
3
Views
443
Replies
1
Views
721
  • Advanced Physics Homework Help
Replies
6
Views
1K
Replies
1
Views
2K
Replies
1
Views
468
  • Introductory Physics Homework Help
Replies
3
Views
3K
  • Introductory Physics Homework Help
Replies
2
Views
867
  • Thermodynamics
Replies
3
Views
4K
  • Thermodynamics
Replies
6
Views
986
Back
Top