Contents:
What is isothermal compression?
Isothermal compression is the process of reducing the volume of a certain mass of fluid, by keeping its temperature constant throughout the process.
Therefore the internal energy of the fluid also remains constant.
Hence, ∆U = 0
Isothermal compression PV and TS diagram:-
Here is the PV and TS plot for the isothermal compression process.
Isothermal compression work:-
For isothermal compression process, formula for the work done is given by,
`W=-RT\times ln[\frac{V_{2}}{V_{1}}]`
Here -ve sign indicates that work is done on the fluid for the compression.
Isothermal compression formula / equation:-
Some of the formulae used in the isothermal compression process are as follows,
i] PV relation:
The relation between pressure and volume for isothermal compression is given by
`[\frac{P_{1}}{P_{2}}]=[\frac{V_{2}}{V_{1}}]`
ii] Change in internal energy:
As the value for ∆T is zero, therefore value for change in internal energy is also zero.
du = 0
iii] Heat transfer:
The heat transfer in isothermal compression is given by,
`Q=-RT\times ln[\frac{V_{2}}{V_{1}}]`
Here -ve sign indicates that heat is rejected by the system.
iv] Change in entropy:
The change in entropy during the isothermal process is given by,
`\Delta S =-mR\times ln[\frac{V_{2}}{V_{1}}]`
v] Change in enthalpy:
The change in enthalpy for the isothermal compression process is zero.
∆h = 0
Is Isothermal compression possible?
The isothermal process is a quasi-static process which means that the process occurs slowly to remain the system in thermodynamics equilibrium.
But the compression process is a faster process, therefore during compression, the temperature of the system also increases. Hence it is not possible to maintain a constant temperature during the compression process, therefore in actual conditions, isothermal compression is not possible.
Read also:
