thermodynamics

Question

A sealed rigid vessel has volume of 1 m3 and contains 2 kg of water at 100◦C. The vessel is now heated. If a safety pressure valve is installed, at what pressure should the valve be set to have a maximum temperature of 200◦C

Answer 1

Process: v = V/m = constant

State 1: v₁ = 1/2 = 0.5 m³/kg from it's 2-phase

State 2: 200°C, 0.5 m³/kg

between 400 and 500 kPa so interpolate

P≅ 400+0.5−0.53422/0.42492−0.53422×(500−400)

= 431.3 kPa