Second law of thermodynamics.pptx

Second law of thermodynamics

1. Second law of thermodynamics

2. Origin of second law of thermodynamics Carnot’s work Clapeyron Recognised carnot’s work. Related ideal carnot engine to the P-V indicator diagram. Proponent of caloric theory. Caloric was conserved in the operation of heat engines. He postulated that work done by a steam engine due to flow of caloric from the hotter body to a colder body. Flow of caloric is analogous to Flow of Fluid ( work due to potential gradient )

3. Lord Kelvin Caloric conservation in the work of carnot. Interconvertibility of heat and work in Joule‘s work. Clausius Justified carnot’s theorem of maximum efficiency. He proved that heat is actually converted in to work. Second Law of thermodynamics Rejected, assumption of no heat loss.

4. A reservoir A reservoir is a device having infinite thermal capacity and which can absorb , retain or reject unlimited quantity of heat without any change in its temperature.

5. Kelvin – Planck statement It is impossible to get a continuous supply of work from a body (or engine) which can transfer heat with a single heat reservoir. Or No process is possible whose sole result is complete conversion of heat in to work. According to this statement zero degree temperature is not attainable ,because no heat is rejected to the sink at zero degree Kelvin.

6. Clausius statement “It is impossible to make heat flow from a body at a lower temperature to a body at a higher temperature without doing external work on the working substance” . Or “No process is possible whose sole result is the transfer of heat from a body at a lower temperature to a body at a higher temperature.”

7. Thank you