HYSYS simulation package

Developed a model using a Hysis Simulation package. 

Compressible fluid program performance has also been checked using the HYSYS simulation package and the results are presented Table 2.19. 

The HYSYS simulation package is used for general flash calculation and to estimate the physical properties. 

The simulator packages such as Aspen Plus and Hysys may be useful in analyzing distillation column systems to improve recovery and separation capacity, and to decrease the rate of entropy production. For example, for the optimization of feed conditions and reflux, exergy analysis can be helpful. A complete exergy analysis, however, should include both an examination of the exergy losses related to economic and environmental costs and suggestions for modifications to reduce these costs. Otherwise, the analysis is only theoretical and less effective. 

When no data are available, there are simulation packages available that can provide estimates. ASPEN and HYSYS are two popular ones. The thermodynamics book by Sandler (1989) contains a diskette that can be used for phase equiUbrium calculations. Additional texts are Prausnitz ef a/. (1980), Prausnitz et al. (1986), and Reid et al. (1987). 

For oil, gas and petrochemical applications, the Peng-Robinson EOS (PR) is generally the recommended property package. For more details, please refer Aspen HYSYS Simulation Basis Manual. 

HYSYS, unlike the majority of other simulation packages, solves the flowsheet after each addition/change to the flowsheet. This feature can be disabled by clicking the... 

If desired, you can save the Fluid Package with the attached reaction sets. This will allow you to reopen this FP in any number of HYSYS simulations. 

For all other components than Hi and HiS the Henry laws constant Hi is assumed to be zero. The constants for these two components have been calculated as a function of temperature from HYSYS (a commercial process simulation package) simulations. The simulated oil had the same boiling point distribution as the actual gas oil. From these simulations we also got the oil vapor pressure. The reactor equation for all compounds is then ... 

HYSYS simulation software was used as a tool to complete the simulation of the process (sample is shown in Fig.l). Fluid packages used in the simulation were Amines package which was used for Acid Gas Sweetening and CO2 Removal units, and Peng Robinson which was used for the rest of the units. When simulation was finalized, the following were collected ... 

The best path to an in-depth understanding of a reactor simulation is a solid understanding and familiarity of how to arrange equations for a reaction system, but when the reactor system becomes too complicated to be simulated with a mathematical package (MATLAB, POLYMATH), then it is the turn of the process simulator package (ASPEN plus, ANSYS, ChemCAD, HYSYS, etc.) to simulate it. 

Selected screen captures from the Aspen HYSYS simulation of the Selexol-based process, (a) Selecting the DBR amines package (b) Temporary specifications for the loaded solvent stream (c) Working around problems with convergence issues with flash drum specifications (d) The final converged flowsheet. 

In the proposed framework, HYSYS. PLANT simulation package is used to validate both the steady state and dynamic models even though the switchability fiom steady state to dynamic mode is not a trivial procedure, as it will be shown in the case study section. 

The application of rigorous simulation packages, such as HYSYS, provides a valuable basis for the design and overall evaluation of advanced process control applications to the simulated processes. Steady state and dynamic simulations help in the process development by analysing and validating the design and/or ideas before their implementation to avoid costly modifications and to ensure safe operation. The simulation of the VCM plant is developed in HYSYS.PLANT in both steady state and dynamic modes and could be used for further economical, environmental and operational evaluations. Table 2 shows the characteristics of the VCM plant model and the detailed data and specifications of the main processes. Fig. 10 shows the process flowsheet of the simulated VCM plant in HYSYS including the main reactors and distillation columns. 

To demonstrate the earlier procedure, the problem of flash distillation is considered. Flash calculations are very common, perhaps one of the most common chemical engineering calculations. They are a key component of simulation packages like Hysys and Aspen. 

The results of material balance calculations obtained with hand calculations, Hysys, PRO/II, Aspen, and SuperPro Designer simulation package are the... 

Develop a working knowledge of the HYSYS steady-state dynamic simulation package. 

Unsteady-state or dynamic simulation accounts for process transients, from an initial state to a final state. Dynamic models for complex chemical processes typically consist of large systems of ordinary differential equations and algebraic equations. Therefore, dynamic process simulation is computationally intensive. Dynamic simulators typically contain three units (i) thermodynamic and physical properties packages, (ii) unit operation models, (hi) numerical solvers. Dynamic simulation is used for batch process design and development, control strategy development, control system check-out, the optimization of plant operations, process reliability/availability/safety studies, process improvement, process start-up and shutdown. There are countless dynamic process simulators available on the market. One of them has the commercial name Hysis [2.3]. 

Throughout this book, we have seen that when more than one species is involved in a process or when energy balances are required, several balance equations must be derived and solved simultaneously. For steady-state systems the equations are algebraic, but when the systems are transient, simultaneous differential equations must be solved. For the simplest systems, analytical solutions may be obtained by hand, but more commonly numerical solutions are required. Software packages that solve general systems of ordinary differential equations— such as Mathematica , Maple , Matlab , TK-Solver , Polymath , and EZ-Solve —are readily obtained for most computers. Other software packages have been designed specifically to simulate transient chemical processes. Some of these dynamic process simulators run in conjunction with the steady-state flowsheet simulators mentioned in Chapter 10 (e.g.. SPEEDUP, which runs with Aspen Plus, and a dynamic component of HYSYS ) and so have access to physical property databases and thermodynamic correlations. 

To comprehend why HYSYS is such a powerful engineering simulation tool, you need look no further than its strong thermodynamic foundation. The inherent flexibility contributed through its design, combined with the unparalleled accuracy and robustness provided by its property package calculations leads to the presentation of a more realistic model. 

This chapter begins by starting HYSYS and how to select the right components and fluid package for simulation pmposes. Knowing how to start HYSYS and get familiar with its desktop is very important in this chapter. The second part is about how to enter and re-enter the simulation enviromnent, and get familiar with simulation flowsheet. In this part, users will be informed some important features of HYSYS. The last part is dealing with how to add and specify material streams for simulation. Variables specification is one of the important steps that users need to understand when dealing with HYSYS. 

Before any simulation can occur, HYSYS needs to imdergo an initial setup. Dining an initial setup, the components and the fluids package that will be used will be selected. 

In the first part of this chapter, we opened it with how to start HYSYS and get familiar with its desktop environment. We also discussed how to select components that will be used in simulation. Selecting the right fluid/thermodynamic package is veiy important and therefore we provided a flowchart that will assist users to select the right thermodynamics models. 

The first step in building any simulation is defining the fluid package. A brief review on how to define a fluid package and install streams is described below. For a complete description, see the previous chapter (Chapter 1 Starting with HYSYS). 

In recent years, property information systems have become widely available in computer packages. Some are available on a stand-alone basis, such as PPDS2 (1997), while others are available within the chemical process simulators, such as ASPEN PLUS, HYSYS.Plant, PRO/n, CHEMCAD, BATCH PLUS, and SUPERPRO DESIGNER. Commonly, constants and parameters are stored for a few thousand chemical species, with programs provided to estimate the property values of mixtures, and determine the constants and parameters for species that are not in the data bank using estimation methods or the regression of experimental data. Virtually all of the property systems estimate the properties of mixtures of organic chemicals in the vapor and liquid phases. Methods are also provided for electrolytes and some solids, but these are less predictive and less accurate. 

Many packages are available for steady-state simulation, as discussed in Chapter 4. To manipulate the linearized models in the Laplace, frequency, and time domains, MATLAB and SIMULINK are used commonly, and example scripts are introduced in Section 21.6. The most recent commercial packages permit steady-state and dynamic simulations. These include HYSYS.Plant, CHEMCAD, and ASPEN DYNAMICS, with the former used in this section and in Section 21.5. 

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