capeOpenEquilibriumProp

Calculates one or more properties at phase equilibrium at one or more specified conditions. Both the flash constraints and the properties that can be calculated using this method are given by capeOpenFlashPropList.

Syntax

[values,...]=capeOpenEquilibriumProp(handle,props,X,prop1,val1,prop2,val2,type)

Arguments

handle: package handle, as obtained from capeOpenGetPackage

propNames: string. Multiple properties can be specified; either separate the properties by a space, or use a string matrix for multiple properties.

X: overall composition. Number of columns must match the number of compounds. Multiple rows indicate multiple evaluation conditions. X is in mole fraction or mass fraction, depending on the current basis.

prop1: string, first constraint property. A list of valid flash constraint properties can be obtained using capeOpenFlashPropList.

val1: value for the first flash constraint property. Can be a column vector for multiple conditions. The unit of measure of the value may depend on the basis.

prop2: string, second constraint property.

val2: value for the second flash constraint property. Can be a column vector for multiple conditions. The unit of measure of the value may depend on the basis.

type: string value indicating the desired solution type. Optional. Valid values are "Unspecified" (default), and if vapor fraction is part of the flash constraints, additional valid values are "Normal" or "Retrograde".

For X, val1 and val2, multiple rows mean multiple conditions. If multiple rows are specified for X, val1 or val2, those values that have multiple rows must have the same number of rows. Those values have a single row signify a constant condition or composition.

Returns

values: column vector of values. One vector will be returned for each property. The number of values in each vector matches the number of evaluation conditions.

As opposed to other functions, this function will return partial results if some of the calculations failed. Numbers that are not known are set to NaN; if the messages are turned on (default), failed calculations will produce a message.

Example


» handle=capeOpenGetPackage('TEA (CAPE-OPEN 1.1)','C1_C2');
» %let's calculate and plot the phase envelope at 1 atm for this system
» frac=0:0.05:1

frac =

  Columns 1 through 8

         0    0.0500    0.1000    0.1500    0.2000    0.2500    0.3000    0.3500

  Columns 9 through 16

    0.4000    0.4500    0.5000    0.5500    0.6000    0.6500    0.7000    0.7500

  Columns 17 through 21

    0.8000    0.8500    0.9000    0.9500    1.0000

» X=[frac' 1-frac']

X =

         0    1.0000
    0.0500    0.9500
    0.1000    0.9000
    0.1500    0.8500
    0.2000    0.8000
    0.2500    0.7500
    0.3000    0.7000
    0.3500    0.6500
    0.4000    0.6000
    0.4500    0.5500
    0.5000    0.5000
    0.5500    0.4500
    0.6000    0.4000
    0.6500    0.3500
    0.7000    0.3000
    0.7500    0.2500
    0.8000    0.2000
    0.8500    0.1500
    0.9000    0.1000
    0.9500    0.0500
    1.0000         0

» P=101325

P =

      101325

» tbub=capeOpenEquilibriumProp(handle,'temperature',X,'pressure',P,'vaporFraction',0)

tbub =

  184.5500
  165.1291
  151.3888
  142.7761
  136.9731
  132.7423
  129.4731
  126.8393
  124.6508
  122.7893
  121.1765
  119.7585
  118.4966
  117.3624
  116.3342
  115.3953
  114.5326
  113.7355
  112.9956
  112.3057
  111.6600

» tdew=capeOpenEquilibriumProp(handle,'temperature',X,'pressure',P,'vaporFraction',1)

tdew =

  184.5500
  183.6246
  182.6609
  181.6550
  180.6022
  179.4972
  178.3334
  177.1029
  175.7962
  174.4011
  172.9025
  171.2807
  169.5095
  167.5530
  165.3595
  162.8514
  159.9023
  156.2847
  151.5130
  144.1551
  111.6600

» plot(frac,[tdew tbub])

» %another example: we start at T = 298.15 K and 1 atm, equimolar, and 
» %we add 1 kJ/mol energy. We want to know the temperature increase
» h0=capeOpenEquilibriumProp(handle,'enthalpy',[0.5 0.5],'pressure',P,'temperature',298.15)

h0 =

  -35.9793

» T1=capeOpenEquilibriumProp(handle,'temperature',[0.5 0.5],'pressure',P,'enthalpy',h0+1e3)

T1 =

  320.2588