Ammonia is throttled from P1 = 169 bars and T1 = 214°C to a very low pressure P2 (note P2 ≪ critical pressure, Pc) using steady flow state device. The ideal gas specific heat can be assumed to be a constant and equal to cp0 = 2.130 kJ/kg K. For ideal gas enthalpy assume h0 = cp0 × T.
a. Verify whether gas at state (1) is real. What about the state of gas at (2): ideal or real?
b. Determine T2 in ° C
c. Estimate the average Joule–Thomson coefficient based on inlet and exit conditions
d. Calculate change u2 – u1 in kJ/kg.
Use Kessler tables and ignore Pitzer factor. Let M = 17.04 kg/kmole.
