8C. The enthalpy and entropy of a two-phase stream by the SRK EOS Back to Main
This page is used to determine the enthalpy and entropy of a two-phase stream by SRK Equation of State Method.
1 Gas
3 Liquid
Q 2 Liquid
Suppose
one has a process in which vaporization or condensation is occurring. One simply looks up the enthalpy (h) at each
of the points shown in order to complete the balance. For this case, Q = m1h1 + m2h2
- m3h3. The
enthalpy of gas is higher than that of liquid to account for latent heat.
The
enthalpy at Points (2) and (3) could be found from a liquid enthalpy
correlation such as Table 8.1. The
vapor enthalpy at Point (1) would be found from a gas enthalpy correlation at
the pressure of the process.
In
solving a vaporization and condensation problem (or any problem involving
multiple streams) remember that mass in equals mass out and energy in equals
energy out, if there is no mass accumulation in the system in question. For our system above
m1 + m2
= m3 m1h1
+ m2 h2 = m3 h3 + Q
Once
the mass balance has been completed and values of "h" found the heat
load "Q" can be calculated.
Where: m =
mass
h = enthalpy
Q = heat transfer
Discuss
temperature and pressure.
To
carry out the entropy and enthalpy calculation the Temperature, Pressure, and
Mole % of each component in the mixture must be entered into the appropriate
entry space. To do so use the mouse to click the courser in the entry space and
input the data.
Once
Temperature, Pressure and mole % of each component in the mixture has been
entered, select Run to execute the
solution.
To
convert unit values of data, please refer to “Set
Auto Convert and Unit Conversion” in the main page.
Entropy
is a thermodynamic property associated with the number of different, equivalent
energy states or spatial arrangements in which a system may be found. Spontaneity is associated with an increase
in the randomness or disorder of a system.
The disorder is expressed by this thermodynamic quantity, given the
symbol S. The more disordered a system,
the larger its entropy.