Source: The Hindu
All About Heat: From Powering Machines to Causing Climate Change
What is Heat?
Heat is a form of energy related to the motion of atoms and molecules.
Temperature reflects the average kinetic energy of an object's particles.
Heat transfer occurs when objects at different temperatures come in contact.
How do we use Heat?
Internal Combustion Engines (ICEs): Convert heat from burning fuel into mechanical work using the Carnot cycle.
Thermal Power Plants: Utilize the Rankine cycle to generate electricity from heat, often from burning fossil fuels or nuclear fission.
The Relationship Between Heat and Work:
Heat and work have the same units but not all heat can be converted to work due to entropy (disorderliness).
Adiabatic processes involve work done without heat exchange (isentropic expansion/compression in Carnot cycle).
Heat Applications Across Industries:
Metallurgy, materials science, mining, refineries, chemical reactions, electronics, meteorology, transportation, and HVAC systems.
Heat pumps and air conditioners utilize reversed Carnot or Rankine cycles.
Heat and Climate Change:
Mitigation: Finding ways to produce heat without fossil fuels and reduce emissions from existing technologies.
Adaptation: Addressing heat waves and their health impacts.
Global warming is caused by the greenhouse gas effect, where certain gases trap heat from the sun, causing the planet to warm.
Additional Points:
Heat engines and pumps operate on various cycles depending on the medium and desired conditions (e.g., Brayton,Stirling cycles).
Heat waves pose significant health risks, especially in vulnerable populations.
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