Question

Consider a rigid system containing water at 22 bars and 375°C:(1) Determine the phase at this condition, why?(2)Determine the specific volume under this condition.(3) If the system is cooled to a temperature of 195 o C at the new thermal equilibrium condition, what is the quality and enthalpy?

Answer 1

Answer and Explanation:

considering a rigid system

fixed volume V = C

water at P1=22bar and T1=375ºC

at 22 bar Tsat =217.2ºC

so...

T1>Tsat

thus

Steam is superheated (phase at this condition)

Specific Volume, V1

V1= Vg * [ Tsup/Tsat]

V1= 0.090663* ((375+273)/(217.2+273))

V1= 0.1198 m³/kg (specific volume under this condition)

V=C, T2=195ºC

from Mollier Diagram we have that..

P2= 6bar (quality and enthalpy)

h2= 2840 KJ/kg

Superheated Steam