Is the efficiency of heat engine more in hilly areas than in plains?

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Discussion Overview

The discussion revolves around the efficiency of heat engines in hilly areas compared to plains, focusing on how temperature differences may affect the performance of these engines. Participants explore theoretical aspects, practical implications, and specific conditions related to heat engine operation.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant suggests that lower temperatures in hilly areas could lead to lower temperatures for both the heat source and sink, questioning if this results in the same efficiency as in plains.
  • Another participant asks for clarification on what is meant by "source" and "sink," indicating a need for specificity regarding the type of heat engine being discussed.
  • A further reply reiterates the initial point about temperature differences and introduces the concept of a Carnot engine, proposing that if the cold sink is at ambient temperature, a colder environment could increase efficiency.
  • This same participant also notes that real heat engines do not typically use ambient temperature as a cold sink, explaining that colder intake air could require more heat from the hot reservoir, potentially reducing efficiency in colder conditions, such as winter for car engines.

Areas of Agreement / Disagreement

Participants express differing views on the impact of temperature on heat engine efficiency, with no consensus reached on whether hilly areas provide a distinct advantage or disadvantage compared to plains.

Contextual Notes

Participants have not fully defined the types of heat engines being discussed, nor have they resolved the implications of using ambient temperature as a cold sink versus other configurations.

avistein
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In hilly areas temp is low than plain areas.So the temperature of source as well as sink must be low.But ratio remains same.So efficiency is same as in plain areas? Is my logic correct? Or anything else? Can it be more?
 
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What source?
 
avistein said:
In hilly areas temp is low than plain areas.So the temperature of source as well as sink must be low.But ratio remains same.So efficiency is same as in plain areas? Is my logic correct? Or anything else? Can it be more?
Assuming you had a Carnot engine with a hot reservoir temperature that was constant but a cold sink that was the same as the ambient temperature, your engine would be more efficient in a colder environment.

But real heat engines don't use the ambient temperature as a cold sink. They simply expel the expanded gas to the environment and take in new air. If that new air gets colder the hot reservoir (a chemical reaction) has to use more heat to get its temperature high enough for the engine to use it to produce mechanical work. This is one reason why car engines are less efficient in the winter.

AM
 

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