Question

The steam is heated to raise its temperature to 150°C. Show the process on a sketch of the p–v diagram, and evaluate the pressure, increase in enthalpy, increase in internal energy, increase in entropy of steam, and the heat transfer. Evaluate also the pressure at which the steam becomes dry saturated.

Answer 1

Answer

Specific volume is given by

$V_m=V/m=0.86/1$

$V_m=0.86kg/m^3$

Here pressure is

$p=2bar=2\times10^5N/m^2$

Internal energy is written as

$E=3PV/2=$ $3\times200000\times0.86$

$E=258000J$

Enthalpy

H=U+PV=258+172=430000J

Entropy is given

S=U/T=258/423=0.61J/K