Suppose X1 has a lower bound of 20 (this means that the upper bound of X2 is 50 minus 20, or 30). The following table shows two components expressed in amounts, proportions, and pseudo-components.
Pseudo-components, in effect, rescale the constrained data area so the minimum amount allowed (the lower bound) of each component is zero. Usually, you can reduce the correlations between the coefficients by transforming the components to pseudo-components. the property packages in the simulation programs (e.g., UniSim, Hysys, Aspen.
The simple usage ofIt also allows you to restrict the range of pipe sizes that may be selected by UniSim Flare during design calculations. If the component represents more than a single real component, the pseudo critical pressure should be used.
For example, a cake mixture cannot contain more than 5% baking powder.Constrained designs (those in which you specify lower and/or upper bounds) produce coefficients which are highly correlated. In case pure components boiling point (NBP i.e. Pseudo-components are coded variables used to simplify design construction and model fitting, and reduce the correlation between component bounds in constrained designs. fractions, HYSYS will automatically regress the 1i term for each pseudo component against the Lee-Kesler vapour pressure curves.