Multi_R_Designer Quick Guide Manual

---

SIMULATION

EDIT USER MODEL INFORMATION:

This functionality allows the user to add proprietary moldel(s) to the list of the models available in Multi_R_Designer and test its (their) performance(s) using the integrated databanks. The User model editor presents two options: the creation of a frame in which the model could be written (Create button), the edition of informations about a user's model previously edited in Multi_R_Designer.

Create: It allows to create a template (if this option is selected) where the inputs and outputs of the model would be defined by the user. A name must be allowed to the model in the User model creator window, then all pertinent informations related to the model could be saved in the Model info editor. The user may give a reference (tittle, year, no of pages...), a type (ex: phenomenological model, empirical correlation ...). Then model's inputs could be selected by pressing Add button in the Input section. In the Property choosier window all variables available in Multi_R_Designer are listed. The selection of more than one variable is done by pressing simultaneously  the mouse left button and Ctrl.  The user may also defined an other variable in the user property section as well as its unity if necessary or specify if it as a code. The same procedure is for the model's output. Moreover, the range of applicability of the inputs-ouputs and some comments about  the model could be specified in the Applicability panel.
The user's model is saved in TrickleBed/user/models/*.binfo if Trickle Bed is the reactor selected in the Reactor option in the main menu. The code of the model could be written using any editor and compiled as it is explained in the example: how to add user's model. The user must check if modellib.jar is in the directory.

SUMMARY OF MODELS' INPUTS:

It allows the user to get an overview of all required inputs for the application of the models integrated in the Multi_R_Designer simulator. For each property, the models are identified in the table heading row and the variables in the first column. The user can have information about any model and variable by pressing the corresponding heading.

START NEW SIMULATION:

This option allows the prediction of hydrodynamics, mass transfer and heat transfer parameters available in Multi_R_Designer with a complete description of the models. Moreover, the simulation results can be saved in a file for a subsequent use with other data processing softwares.

The Start new simulation window presents: the parameters to be simulated (Output panel), the simulation inputs (Input panel), the simulation results (Result panel) and the MEXA.

Properties: Hydrodynamics, heat and mass transfer properties are simulated using most important models and correlations available in the open literature.

Simulated Outputs: (ex: for the trickle bed reactor) The Output panel is divided in three sections (columns):

 
1) Properties: classified in alphabetical order

• Dynamic liquid holdup
• Ergun constant E1
• Ergun constant E2
• Frictional pressure drop
• General flow regime: Classifies the operation regime in three important categories, the low interaction regime (LIR), high interaction regime (HIR) and transition regime between LIR and HIR.
• k_G: Gas-side mass transfer coefficient
• k_Ga_LG: Gas-side volumetric mass transfer coefficient
• k_L: Liquid-side mass transfer coefficient
• k_La_LG: Liquid-side volumetric mass transfer coefficient
• k_LS-particle: Liquid-particle mass transfer coefficient
• k_LSphi_LS-particle: Liquid-particle mass transfer coefficient for partial wetting
• K_LSphi_LS-Reactor's wall: Global liquid-solid mass transfer coefficient for partial wetting at the wall reactor
• LG interfacial area: Liquid-to-gas interfacial area
• Liquid axial dispersion coefficient
• Radial effective thermal conductivity
• Shear slip correction factor in the extended Holub model (fs)
• Static liquid holdup
• Total liquid holdup
• Total pressure drop
• G (gas mass flow rate) at trickle/pulsing transition flow
• L (liquid mass flow rate) at trickle/pulsing transition flow
• Velocity slip correction factor in the extended Holub model (fv)
• Wall heat transfer coefficient
• Wetting efficiency

2) Unit: unit system in which the selected property will be simulated. It can be changed from SI system to an other unit system.

3) Model: several models are available in the simulator for each parameter. Near , the fraction A/B means that A models, among B available, are selected to run simulation.

• The list of models is presented in a separate dialog window . The model selection is achieved by pressing the Use heading. The check boxes are used for individual selections.
• Their performance based on the Multi_R_Designer integrated databank is given in terms of AARE (average absolute relative error) and standard deviation of the AARE.
• Specific information about a model is available in the Info dialog window:
• In the General tab, the publication Reference for the specified model is depicted as well as the Type (empirical correlation using dimensionless inputs), model Inputs in dimensional form (liquid density, gas density, etc...) and model Output in dimensional form.
• In an Applicability tab, a domain of validity for each input is given. The units (if available) can be changed. Simulated parameters marked by open symbols on graphics indicate that at least one input domain of validity was violated. Some pertinent Comments about the formulation of the model may be also presented in this panel.
• All these information can be printed or saved in .html file by selecting Export.

Simulation Inputs: Once the models are selected, their inputs are displayed in the Input panel. It contains two sub-panels: a Model panel and a User panel.

• In the Model tab, the inputs can be introduced in three ways: Manually, from a File (in .csv format). This can be selected in the Mode case. Some inputs are qualitative variables such as the general and specific flow regime, the nature of the fluids (coalescing and foaming), the packing materials (beads, cylinders, ...), and they are identified by the following icon (  ). The user should consult the coded variables before any simulation. Moreover, if the simulation is carried out from a .csv file, it would be wise to use a frame file. Data assignation from the .csv file to the Multi_R_Designer inputs would become easier. The icon ( ) near an input means that it can be estimated from a correlation/model if not available in the user's file. The converter option allows the user to replace an input by an associated variable (which combines two or more inputs) in order to reduce the total number of inputs.
• In the User tab, data can be added such as the experimental output (to display on a parity plot), or other pertinent information which are stored in the results' file.

Simulation Results: The Result panel contains all the variables set up in the Input panel (identified by input) and the predicted outputs (identified by the model's name).

• Variables (inputs or outputs) estimated by a model are identified in blue in the column heading (its selection will display a information panel about the model).
• If inputs are not available, a <null> is written and a Missing input ... (of this variable) is also indicated in the corresponding model's output.
• A value (model's output) displayed in red means that it is out of range relative to the applicability specifications. Focusing the corresponding cell will give the calculated value and the reason why it is considered invalid. These invalid data are symbolized by open points when plotted.
• If the model is not applicable, a brief comment is given.

Mexa: MEXA is a tool helping the user to find the best model predicting hydrodynamics, mass or heat transfer properties providing a range of operating conditions such as velocities, fluid properties and packing properties (common model inputs). If the user wants to predict, for example, total liquid holdup for specific operating conditions, he can assign a range for the liquid and gas velocities, particle dimensions and choose one or several models available in the Multi_R_Designer simulator. MEXA will find the number of experimental data in the Multi_R_Designer integrated databank matching the specified conditions and will divulge the performance of the selected models on these data. With this tool, the user can determine the model or correlation exhibiting the best prediction capability of the studied property for the operating condition setup.
 

AUTOMATIC SIMULATION SETUP: This option allows the selection of properties to be automatically simulated on a User database.

The Automatic simulation setup window presents two panels:

• Properties panel: contains all the properties which are automatically simulated. The undesired variables may be deselected in the Sim field. Nevertheless, these variables can be used as inputs to estimate other models' output (example: Ergun's constants E1 and E2 to predict pressure drop or liquid holdup in some models). If  these data are not available in the user database, a model can be chosen in the Default as input column, to evaluate them. No default means that this property will not be estimated if used as input in some model.
• in Models panel are listed the models used to automatically simulate the selected properties. Some models may be deselected (not used) if desired.

AUTOMATIC SIMULATION OF USER DATABASE:

• An automatic simulation can be processed immediately after the creation of  a user database (see User database) or later by selecting Simulation/Automatic simulation of user database in the bar menu. The user have to choose the name and location of the user database and the file where the simulated data will be stored, if this was not done previously (see Open user database). Once the simulation finished, a simulation report is displayed in an Automatic simulation log window. For each property simulated, the model used as well as the processing time is reported. The ? symbol means that the simulation corresponding to the model was achieved because it was not applicable or an input was missing (not found in the user database).