Air at 25°C and 5 atm is throttled by a valve to 1 atm. If the valve is adiabatic and the change in kinetic energy is negligible, determine the exit temperature of air. Solve using appropriate software.

Respuesta :

Answer:

[tex]T_{2} = 25^{\circ}C[/tex]

Solution:

As per the question:

Temperature, [tex]T_{1} = 25^{\circ}C[/tex]

Pressure, [tex]P_{1} = 5 atm[\tex]

Now,

We know that the process of throttling occurs in adiabatic conditions where no heat is transferred in between the system and the surrounding, i.e., Q = 0

Thus no work is done in this process, i.e., W = 0

Enthalpy also remains same from one state to the other state, i.e., [tex]\Delta h = 0[/tex]

Therefore, from the eqn:

[tex]Q - W = \Delta h + \Delta KE[/tex]

We can write:

[tex]\Delta h = h_{1} - h_{2} = 0[/tex]

[tex]\Delta h = C_{p}\Delta T[/tex]

[tex]C_{p}(T_{2} - T_{1}) = 0[/tex]

Thus

[tex]T_{1} = T_{2} = 25^{\circ}C[/tex]

where

[tex]T_{2}[/tex] = Exit temperature