Problem # p009

Open System. Conservation of energy. Entropy

Steam is streaming out of a tank through a nozzle in an adiabatic, reversible fashion and is expanding to a pressure of 1 MPa.
The conditions inside the tank are :

T = 700oC , p = 6 MPa , v = 0.07352 m3/kg

u = 3453.1 kJ/kg , h = 3894.2 kJ/kg , s = 7.4234 kJ/(kg K)

Assume that the steam enters the nozzle with negligibly small velocity and that changes in potential energies can be neglected.

Properties of superheated steam at 1 MPa
    T [oC]     p [MPa]     v [m3/kg]     u [kJ/kg]     h [kJ/kg]     s [kJ/(kg K)]
320 1.0 0.2678 2826.1 3093.9 7.1962
360 1.0 0.2873 2891.6 3178.9 7.3349
400 1.0 0.3066 2957.3 3263.9 7.4651

Based on the information given above determine :
  1. The enthalpy and temperature of the exiting steam
  2. The exit velocity
Linear interpolation is required. Note : 1kJ/kg = 1000 Nm/kg = 1000 (m/s)²