IPSEpro Program Modules

PSE is IPSEpro's Process Simulation Environment. With PSE you create a process model based on components from a specific IPSEpro library.

PSE provides a user-friendly flowsheet editor for setting up process models. The user selects the required components from the library menu and arranges them appropriately. All process data is entered directly in the flowsheet. The results are directly displayed on the scheme. PSE generates output protocols automatically, at the end of a simulation run.

PSE uses an equation oriented approach. Optimized mathematical methods guarantee fast and accurate calculations. To solve a system of equations, PSE adopts a 2-phase approach:

Analysis Phase: In the analysis phase PSE first checks the model for errors in the process specifications. If the specifications are correct, it determines the optimum solution method.

Numerical Solution Phase: In this phase PSE solves the equations with the numerical methods pre-defined by the analysis phase.

MDK, IPSEpro's Model Development Kit, is a programming environment that offers all the capabilities required to define and build new component models and to translate them into a form that can be used by IPSEpro's Process Simulation Environment - PSE.

MDK consists of two functional units: MDK Model Editor and MDK Model Compiler.

The Model Editor allows the user to design icons that represent the models and to describe their behavior mathematically.

Model

The Model Editor allows the user to design icons that represent the models and to describe their behavior mathematically. MDK Model Editor makes use of a model description language provided by IPSEpro.

Model Description Language - MDL

MDK provides a Model Description Language (MDL) to describe models mathematically. MDL is highly intuitive due to the fact that it is based on standard mathematical notations. MDL is closely integrated with MDK's user interface.

Simple MDL Code Sample

Important facts about MDL:

• In MDL the user actually writes equation, not assignments like in traditional programming languages. Therefore it is permitted to use expressions on the left hand side.
• The sequence how the equations are written is irrelevant for the actual solution process. PSE's solver determines the optimum solution sequence independently and according to the actual process model.
• It is allowed to use conditional statements inside an equation.
• In the example above "t1" is a test condition. If this condition is not satisfied at the end of a solution process, PSE issues a warning.

Model Compiler

MDK Model Compiler translates the model descriptions written via the Model Editor in MDL into a binary format that guarantees high performance when a process model is solved in IPSEpro's Process Simulation Environment (PSE).

IPSEpro-PSXLink is an extension module that allows to integrate PSE projects with Microsoft Excel worksheets.

Data exchange can be done in both directions:
Use data from Excel calculations as input for IPSEpro-PSE projects.
Use results of IPSEpro-PSE simulations in Excel spreadsheets for further post-processing (e. g. creating diagrams, reports).

It easily possible to carry out parameter variations. Thus sensitivity analysis can be done to identify how certain variables affect calculation results (e. g. effect of component load on cycle efficiency).

IPSEpro-PSE simulations can be completely controlled from Microsoft Excel. No additional screens have to be opened.

PSOptimize is IPSEpro's parameter optimization module

In many projects, once the process layout has been defined, one of the most important issues is to choose the best process parameters. Often these values are determined by technical standards and the availability of appropriate components.

However, there are also many situations where process engineers have freedom in choosing these parameters. Through time consuming variations they attempt to find appropriate values for the process parameters.

With IPSEpro you do not need to resort to variations. The optimizer module of IPSEpro, PSOptimize, allows you to carry out formal optimizations to find the process parameters that optimize the criterion that you define.

Using IPSEpro-PSOptimize you can:

• Define and run your optimization directly in IPSEpro-PSE.
• Have complete freedom in defining your optimization criterion. 
• Select any number of decision variables.                 

PSValidate is the IPSEpro module available for both, that is responsible for increasing the accuracy of your process model, adjusting component models to expected operational behavior, as well as validating results of acceptance tests of a plant.

When you use measured values, you have to be aware that the measured values are never consistent. Since measurements are always subject to errors, the values will not satisfy the model equations. Basic principles, like conservation of mass and energy will not be satisfied.

Process engineers often attempt to solve those kind of problems by identifying "reliable" values and disregarding others. However, this approach is not satisfying since it is time consuming and not repeatable. Using IPSEpro's validation module PSValidate, you have the ideal solution at your disposal.

Using PSValidate

You have a well defined method that allows you to use all data and to exploit the redundancies of the measured data to improve your results within IPSEpro projects.

PSValidate uses statistical methods to eliminate redundancies and to obtain more accurate data. It allows you to:

• Get the most probable and consistent picture of the state of a process.
• Identify sensor failures.
• Increase the accuracy of your model by identifying "weak points".
• Adjust component models to operational behavior.
• Analyze the results of acceptance tests and assess if the required specifications are met.

PSDynamics is IPSEpro's dynamic process simulation module. With PSDynamics it is possible to simulate a wide range of dynamic models.

IPSEpro is often used to investigate the performance of processes where all process parameters can be considered as constant. Such processes are referred to as steady state processes. Storage of energy or mass is neglected. Mathematically such a process is represented by a system of algebraic equations.

If it is necessary to know how a process responds to changes over time it is in general necessary to take into account storage e.g. of energy or mass. A process where changes over time are relevant is called a dynamic processes. Mathematically such a process is represented by a mixed system of differential and algebraic equations.

PSDynamics adds all the functionality that is required to describe a dynamic process and to solve the model. At the core of PSDynamics is a powerful and robust solver that solves the model equations fast and efficiently. This is complemented with functionality for entering external influences over time and for conveniently displaying simulation results.

PSEasy is the IPSEpro module for calculating process models with fixed cycle layout.

Every simulation model that has been set up with IPSEpro-PSE can be transformed into an IPSEpro-PSEasy model. This way the respective cycle layout can no longer be changed. Parameter and variable settings can be changed.

The use of PSEasy is particularly appropriate for standard cycle designs,  where the pre-established process model can be analyzed for different parameter settings by plant operators, but is protected against cycle design modifications.

Existing plant configurations can be represented in IPSEpro-PSEasy models for qualification of operating conditions or for what-if analysis.

IPSEpro-PSEasy uses the same calculation engine as IPSEpro-PSE. This guarantees accurate and consistent results.

• the same calculation engines as PSE and PSEasy for system solution, optimization and data validation. This guarantees that solutions obtained on-line are consistent with results of off-line "What-If" studies.
• the same file formats as PSE and PSEasy for process models. This allows free exchange of process models between on-line and off-line applications.

PSServer implements a freely configurable interface for data exchange with any Plant Data Management (PDM) System. Any actually required calculation sequence is freely programmable.