Page 115 - DJJ20063- Thermodynamics 1
P. 115
DJJ20063- Thermodynamics 1
a) Heat energy supplied = change in enthalpy of fluid
Q = H2 – H1
= m( h2 - h1 )
= 2.25( 280 – 210 )
= 157.5 kJ
b) For a constant pressure process
W = P(V2 – V1)
5
= 7 x 10 x ( 0.2 – 0.1)
4
= 7 x 10 J
= 70 kJ
Applying the non-flow energy equation
Q – W = U2 – U1
gives
U2 – U1 = 157.5 – 70
= 87.5 kJ
106 | P a g e
