Question

Determine the phase and the specific volume for ammonia

a. –10°C, 150 kPa

b. 20°C, 100 kPa

c. 60°C, quality 25%

Answer 1

Ammonia, NH3, properties

(a) P < Psat(-10 °C) = 291 kPa

Superheated vapor v = 0.8336 m3 /kg

(b) Psat = 847.5 kPa so P < Psat

Superheated vapor v = 1.4153 m3 /kg

(c) enter with T (this is two-phase L + V)

v = vf + x vfg = 0.001834 + x × 0.04697 = 0.01358 m3/kg