Experiments

Measurements »
The Measurements Node is used to select the measured variables in the experiment sets. You may also select variables that may be not be measured in this grid. This is useful when you are interested in seeing the evolution of these variables along with the other variables. To ensure that REX does not consider this variable for reconciliation, you should check that the variable is not selected in the Reconciled Measurements grid of the Weights node, or, ensure that the weighting factors for this variable are indeed zero. Pseudo-compounds and derived quantities may also be reconciled. To learn more about the pseudo-compound calculations at data points, please view the information provided in Note1. Grid Views Actions Grid Views Basic Measurements Basic Measurements This grid displays the list of variables and is organized as follows: Item: This column displays the list of variables (items) Total Moles or Total Mass: Check this column to specify the item in this row as measured. For compounds, checking this row means that you will provide the Total Moles / Mass of this compound in the reactor. Furthermore, common variables such as temperature and pressure are also provided in the same Total Moles / Mass data series. Note that the data provided in the Total Moles / Mass Series at the initial point (or reactor entry) is assumed to be the initial (or inlet) condition for the REX reactor model. Phase Name(s): Check this column to specify the item in this row as measured in the corresponding phase. The values provided in each phase at the initial point(or reactor entry) are not used in the reactor model specification, and are used only as estimates of phase compositions. REX will calculate the phase compositions directly from the initial conditions provided in the Total Moles series and the phase distribution parameters. Note1: Pseudo-compounds and derived quantities may be reconciled only in the Total Moles series. The values of the pseudo-compounds at the datapoints are calculated as follows. Care should be taken to provide the measured values consistent with the way the calculated values are computed. Method 1: For pseudo-compounds that are Not Conserved and Not Specified by Data, the pseudo-compound value at each data point is calculated by using the reaction phase molarity, partial pressure or mass density of the compounds that are in the defining equation of the pseudocompound. The choice of molarity, partial pressure or mass density is based on the concentration option selected in Units Configuration. For example, with this method, when a pseudo-compound is a linear combination of real compounds, but marked as not conserved, the equivalent molarity, partial pressure or mass density of the pseudo-compound is shown as the calculated value in the total moles series at each data point Method 2: For Conserved pseudo-compounds that are Not Specified by Data, when Molarity is selected in the Units Configuration, the pseudo-compound is calculated in all phases, and the values in each phases are multiplied by the phase's volume, to obtain an equivalent total moles or total mass for the pseudocompound in the reactor. Method 3: For Conserved pseudo-compounds that are Not Specified by Data, when Partial Pressure is selected in the Units Configuration, REX internally calculates an equivalent molarity for the pseudo-compounds in the gas phase (based on an ideal gas law), and that equivalent molarity is multiplied by the phase volume. This is then added to the moles of the conserved pseudocompound in other phases (for a multiphase reactor) to calculate an equivalent total moles over the whole reactor which may then be reconciled. Method 4: For pseudo-compounds that are Specified by Data, no reconciliation can be done. However, you must provide values for the Datapoints in order to numerically define values for this special type of pseudo-compound. For derived quantities, the value to be reconciled is obtained from its definition in the Derived Quantities node. Note2: Variables such as temperature and pressure which are assumed to be uniform across the phases are available for specification only in the Total Moles / Mass series. Likewise, inflows and outflows must be specified in the Total Moles / Mass data series. Top of Topic Actions Merged Sets Included Sets Quick Run Open Solver Merge Sets When Merge Sets toggle button is active, the data for all the sets is merged into one child node Sets. When the sets are merged, you may add new experimental datapoints only with the Add Datapoint action on the Sets node . When Merge Sets toggle button is inactive, the experimental data are shown separately by set, as it is shown by default. Here, each set is a child node of this node. This action can be executed in the Measurements node, the Initialization Values node and the Profiles node. Whatever is selected in any one of these nodes results will impact in all of these nodes. Included Sets When Included Sets toggle button is active, it is shown only the included sets in Experiments node. if Included Sets toggle button is inactive, all sets are displayed. Top of Topic See Also: Project Explorer Pseudo-Compounds Units Configuration Derived Quantities Estimation Experiments

The Measurements Node is used to select the measured variables in the experiment sets.
You may also select variables that may be not be measured in this grid. This is useful when you are interested in seeing the evolution of these variables along with the other variables. To ensure that REX does not consider this variable for reconciliation, you should check that the variable is not selected in the Reconciled Measurements grid of the Weights node, or, ensure that the weighting factors for this variable are indeed zero.
Pseudo-compounds and derived quantities may also be reconciled. To learn more about the pseudo-compound calculations at data points, please view the information provided in Note1.

Grid Views

Actions

Grid Views

Basic Measurements

Basic Measurements

This grid displays the list of variables and is organized as follows:

Item: This column displays the list of variables (items)
Total Moles or Total Mass: Check this column to specify the item in this row as measured. For compounds, checking this row means that you will provide the Total Moles / Mass of this compound in the reactor. Furthermore, common variables such as temperature and pressure are also provided in the same Total Moles / Mass data series. Note that the data provided in the Total Moles / Mass Series at the initial point (or reactor entry) is assumed to be the initial (or inlet) condition for the REX reactor model.
Phase Name(s): Check this column to specify the item in this row as measured in the corresponding phase. The values provided in each phase at the initial point(or reactor entry) are not used in the reactor model specification, and are used only as estimates of phase compositions. REX will calculate the phase compositions directly from the initial conditions provided in the Total Moles series and the phase distribution parameters.

Note1: Pseudo-compounds and derived quantities may be reconciled only in the Total Moles series. The values of the pseudo-compounds at the datapoints are calculated as follows. Care should be taken to provide the measured values consistent with the way the calculated values are computed.

Method 1: For pseudo-compounds that are Not Conserved and Not Specified by Data, the pseudo-compound value at each data point is calculated by using the reaction phase molarity, partial pressure or mass density of the compounds that are in the defining equation of the pseudocompound. The choice of molarity, partial pressure or mass density is based on the concentration option selected in Units Configuration. For example, with this method, when a pseudo-compound is a linear combination of real compounds, but marked as not conserved, the equivalent molarity, partial pressure or mass density of the pseudo-compound is shown as the calculated value in the total moles series at each data point
Method 2: For Conserved pseudo-compounds that are Not Specified by Data, when Molarity is selected in the Units Configuration, the pseudo-compound is calculated in all phases, and the values in each phases are multiplied by the phase's volume, to obtain an equivalent total moles or total mass for the pseudocompound in the reactor.
Method 3: For Conserved pseudo-compounds that are Not Specified by Data, when Partial Pressure is selected in the Units Configuration, REX internally calculates an equivalent molarity for the pseudo-compounds in the gas phase (based on an ideal gas law), and that equivalent molarity is multiplied by the phase volume. This is then added to the moles of the conserved pseudocompound in other phases (for a multiphase reactor) to calculate an equivalent total moles over the whole reactor which may then be reconciled.
Method 4: For pseudo-compounds that are Specified by Data, no reconciliation can be done. However, you must provide values for the Datapoints in order to numerically define values for this special type of pseudo-compound.
For derived quantities, the value to be reconciled is obtained from its definition in the Derived Quantities node.

Note2: Variables such as temperature and pressure which are assumed to be uniform across the phases are available for specification only in the Total Moles / Mass series. Likewise, inflows and outflows must be specified in the Total Moles / Mass data series.

Top of Topic

Actions

Merged Sets

Included Sets

Quick Run

Open Solver

Merge Sets

When Merge Sets toggle button is active, the data for all the sets is merged into one child node Sets. When the sets are merged, you may add new experimental datapoints only with the Add Datapoint action on the Sets node .
When Merge Sets toggle button is inactive, the experimental data are shown separately by set, as it is shown by default. Here, each set is a child node of this node.

This action can be executed in the Measurements node, the Initialization Values node and the Profiles node. Whatever is selected in any one of these nodes results will impact in all of these nodes.

Included Sets

When Included Sets toggle button is active, it is shown only the included sets in Experiments node. if Included Sets toggle button is inactive, all sets are displayed.

Measurements »