How  much heat must be supplied to water at 180 degrees celcius to make 1 kg of wet steam at 9000 kpa , having a dryness fraction of 80% ?.

How  much heat must be supplied to water at 180 degrees celcius to make 1 kg of wet steam at 9000 kpa , having a dryness fraction of 80% ?.

I was given this as an answer ;but dont know where they found the enthalpy at a 180 degrees in steam table , and dont know how they got 163 for h1 at then end equation to calculate heat ?

given;

mass,m=1 kg

temperature , t =180 degrees celcius

pressure,p=9000kpa

find q

solution:

from steam table at 180 degrees celcius , the enthalpy , hf=h10103 kj/kg

from the steam table at 9000 kpa hf=763.22

hfg=1378.9

therefore :

h2=hf + x (hfg)

=763.22 +0.8(1378.9)

=1866 kj/kg

calculate heat required:

q=h2-h1=1866-163=1703