Problem # p039

Mixing of 2 streams of steam, entropy change

At a pressure of p=1 MPa two streams of superheated water vapor, a and b, are mixed.

Stream a : T=500oC at 0.4 kg/s
Stream b : T=250oC at 0.8 kg/s

Mixing takes place inside a well insulated container. Using the steam table provided below and linear interpolation when necessary, determine :

  1. The mass flow rate, enthalpy and temperature of the steam exiting the container.

  2. The entropy entering the mixing container per second.

  3. The entropy leaving the mixing container per second.

  4. The entropy produced per second during the mixing process.

      ToC   v[m3/kg]    u[kJ/kg]   h[kJ/kg]    s[kJ/(kg K)]
      2000.20602621.92827.96.6940
      2500.23272709.92942.66.9247
      3000.25792793.23051.27.1229
      3500.28252875.23157.77.3011
      4000.30662957.33263.97.4651
      5000.35413124.43478.57.7622