Heat Engine - Maximum Efficiency

Celsius and one at 375 degrees Celsius can be calculated using the equation e = 1 - Tc/Th, where Tc is the temperature of the cold reservoir and Th is the temperature of the hot reservoir. In summary, the maximum efficiency for this engine is 93.33%.
  • #1
science.girl
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0

Homework Statement


A heat engine operates between a reservoir at 25 degrees Celsius and one at 375 degrees Celsius. What is the maximum efficiency possible for this engine?


Homework Equations



e = [tex]\frac{Qc}{Qh}[/tex]


The Attempt at a Solution



I'm afraid that the equation above requires units in Joules to calculate thermal efficiency. Is there an equation adapted for this situation? Or does this require more figuring?
 
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  • #2
Just a little more figuring ;) think of the Carnot cycle ;)
 
  • #3
Check your textbook for another efficiency equation, one involving absolute temperatures rather than Q's.
 
  • #4
science.girl said:

Homework Statement


A heat engine operates between a reservoir at 25 degrees Celsius and one at 375 degrees Celsius. What is the maximum efficiency possible for this engine?

Homework Equations



e = [tex]\frac{Qc}{Qh}[/tex]
Efficiency is the ratio of Energy (work) out to Energy (heat flow) in. This is not Qc/Qh

AM
 

FAQ: Heat Engine - Maximum Efficiency

What is a heat engine?

A heat engine is a device that converts heat energy into mechanical work. It typically involves the transfer of heat from a high temperature source to a lower temperature sink, which results in the production of work.

How does a heat engine work?

A heat engine works by utilizing the principles of thermodynamics, specifically the laws of thermodynamics. The first law states that energy cannot be created or destroyed, only transformed. The second law states that heat always flows from a high temperature source to a lower temperature sink. By harnessing this flow of heat, a heat engine is able to produce work.

What is the maximum efficiency of a heat engine?

The maximum efficiency of a heat engine is determined by the Carnot efficiency, which is equal to the ratio of the temperature difference between the hot and cold reservoirs to the temperature of the hot reservoir. This means that the maximum efficiency of a heat engine is dependent on the temperature at which it operates.

How can the efficiency of a heat engine be improved?

The efficiency of a heat engine can be improved by increasing the temperature difference between the hot and cold reservoirs, or by decreasing the temperature of the cold reservoir. This can be achieved through various methods, such as using better insulation or optimizing the design of the engine.

What are some real world applications of heat engines?

Heat engines are used in a wide range of applications, including power generation, transportation (such as cars and planes), and industrial processes. They are also commonly used in household appliances, such as refrigerators and air conditioners, to transfer heat and cool a space.

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