How to select fluid package in Aspen Hysys

 

Table below provide a rough guide on selection of fluid package.

However, the guide doesn't provide a detail description in selection of   activity coefficient.

Source: Elliot, Liraj : Prentiice Hall , 1999

Non-intrusive type pig detector

 

Generally, pig detector is group by intrusive and non-intrusive type. For non-intrusive type pig, there is no mechanical part that required to be installed inside the pipeline.

Henceforth, it has a number of benefits:

1. Any type of PIG can be detected in both directions.

2. There are no mechanical moving parts resulting in low maintenance.

3. Non-intrusive design benefits include:

- No wetted parts

- No pipe pressure drop

- Easy to install (no tappings or welding required)

- No shutdown required for installation

4. Finally, it is easy to retrofit for existing installations with no need for modifications to the piping or PIG

The non-intrusive pig detector is an acoustic device. When a PIG travels through the pipe, the friction between the PIG and the pipe will generates a characteristic noise. This noise contains information that can be interpreted to gain more knowledge on the situation inside the pipe. The noise is detected and can be transformed into digital signal.

Image courtesy from Roxar Pig Detector catalogue. Emerson Process Management.

Typical process in refinery

• Fractionation (distillation) is the separation of crude oil in atmospheric and vacuum distillation towers into groups of hydrocarbon compounds of differing boiling-point ranges called "fractions" or "cuts."
• Conversion Processes change the size and/or structure of hydrocarbon molecules. These processes include:
  • Decomposition (dividing) by thermal and catalytic cracking;
  • Unification (combining) through alkylation and polymerization; and
  • Alteration (rearranging) with isomerization and catalytic reforming.
• Treatment Processes are intended to prepare hydrocarbon streams for additional processing and to prepare finished products. Treatment may include the removal or separation of aromatics and naphthenes as well as impurities and undesirable contaminants. Treatment may involve chemical or physical separation such as dissolving, absorption, or precipitation using a variety and combination of processes including desalting, drying, hydrodesulfurizing, solvent refining, sweetening, solvent extraction, and solvent dewaxing.
• Formulating and Blending is the process of mixing and combining hydrocarbon fractions, additives, and other components to produce finished products with specific performance properties.
• Other Refining Operations include: light-ends recovery, sour-water stripping, solid waste and wastewater treatment, process-water treatment and cooling, storage and handling, product movement, hydrogen production, acid and tail-gas treatment and sulfur recovery.
• Auxiliary Operations and Facilities include: steam and power generation, process and fire water systems, flares and relief systems, furnaces and heaters, pumps and valves, supply of steam, air, nitrogen, and other plant gases, alarms and sensors, noise and pollution controls, sampling, testing, and inspecting and laboratory, control room, maintenance, and administrative facilities.

 

Problem In Plotting Txy Diagram In Hysys 8.4

 

A strange condition where the Equilibrium Unit Operation Extension fail to generate neither Txy plot nor xy plot.

The Plot and update plot tab seems unresponsive.

Your Comment is highly appreciated.

 

Controller Action: Direct and Reverse

Controller Action: Direct and Reverse
There are two types of controller action: Direct action and reverse action.
What type of change in the controller output (increase or decrease) is required to bring the process variable in line with the control setpoint?” If an improper action setting is selected, the controller will respond in a manner opposite the intended response (increasing temperature, rather than decreasing it, for example).
Direct action causes the output value to change in the same direction as the change in PV (increase in PV à increase in controller output).
The control valve will fail in the closed position.
The error is initially positive (PV - SP>0). The positive error is counteracted by an increased controller output; therefore, this controller is direct-acting.

Reverse action causes the output value to change in the opposite direction as the change in PV (increase in PV à decrease in controller output).
The control valve will fail in the open position.
The error is initially positive (PV - SP>0). The positive error is counteracted by a decreased controller output; therefore, this controller is reverse-acting.

 
Remember:
PV ­+ , MV + ­ = Direct Control
PV +,  ­MV -   = Reverse Control
 
Good reference of Controller action can be found in:

1. http://www.controlglobal.com/articles/2014/controllers-direct-vs-reverse-acting-control/

Great Hysys Training material

Internet is always a great place to learn. One of the interesting manual available to learn hysys especially for young engineers is:

HYSYS: an introduction to chemical engineering simulation for UTM Degree++ program

The book is written by Abd Hamid, Mohd Kamaruddin for University Technology Malaysia/
Below is the extract obtain from UTM website
Abd Hamid, Mohd Kamaruddin (2007) HYSYS: an introduction to chemical engineering simulation for UTM Degree++ program. Manual. Universiti Teknologi Malaysia. (Unpublished)

                               Click the link to download the tutorial manual.
 
 
Also click Aspen and Hysys tag  for more information.

 

Abstract

HYSYS is a powerful engineering simulation tool, has been uniquely created with respect to the program architecture, interface design, engineering capabilities, and interactive operation. The integrated steady state and dynamic modeling capabilities, where the same model can be evaluated from either perspective with full sharing of process information, represent a significant advancement in the engineering software industry. The various components that comprise HYSYS provide an extremely powerful approach to steady state modeling. At a fundamental level, the comprehensive selection of operations and property methods allows you to model a wide range of processes with confidence. Perhaps even more important is how the HYSYS approach to modeling maximizes your return on simulation time through increased process understanding. 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. HYSYS is widely used in universities and colleges in introductory and advanced courses especially in chemical engineering. In industry the software is used in research, development, modeling and design. HYSYS serves as the engineering platform for modeling processes from Upsteam, through Gas Processing and Cryogenic facilities, to Refining and Chemicals processes. There are several key aspects of HYSYS which have been designed specifically to maximize the engineer’s efficiency in using simulation technology. Usability and efficiency are two obvious attributes, which HYSYS has and continues to excel at. The single model concept is key not only to the individual engineer’s efficiency, but to the efficiency of an organization. Books about HYSYS are sometimes difficult to find. HYSYS has been used for research and development in universities and colleges for many years. In the last few years, however, HYSYS is being introduced to universities and colleges students as the first (and sometimes the only) computer simulator they learn. For these students there is a need for a book that teaches HYSYS assuming no prior experience in computer simulation.

Cause of thermal expansion inside cavity:

 
Cause of thermal expansion inside cavity:
For the floating type/soft seat ball valve, and liquid fluid
1) In case of temperature of fluid and atmosphere has some increasing(for example""water: 30°C"", depends on fluid), and valve not operated for the time of increasing temperature,"
2) In case of valve position is "Full Open" for the time of increasing temperature,
3) In case of valve position is ""Full Close"" for the time of increasing temperature and differential pressure between upstream and downstream is below 0.98MPa,
4) In case of operation frequency is little and ball seat is new,
The above conditions are happened more than 2subjects, fluid inside body cavity(inside pocket) is increased pressure by thermal expansion. This condition is called "Thermal Expansion Inside Cavity".
 
Thermal Expansion inside Cavity is happened other problems as followings.
1) Operation torque is increased suddenly, and happened operation problem for on-off valve and manual valve.
2)There is possibility to get damage for seal parts.
3)There is a possibility to get damage for valve body. (especially for cast iron body.)

 
In order to avoid thermal expansion in cavity:
1)Making a hole (bypass) body cavity to valve port. (For the time of increasing temperature and valve position ""Full Open"", body cavity and port is same pressure condition.) Standard Spec. for HF5 model."
2) In case of increased temperature, valve position "full open" and fluid pressurizing direction 1-way,
1. make a relief groove on ball seat at upstream side.
2. make a hole on ball face at upstream side pass to port.
3) In case of increasing tempertaure, valve position ""full close"" and fluid pressurizing direction non-fixed, valve should be used Trunnion type ball valve."


 
Reference:
http://www.hisaka.co.jp/english/valve/techDoc/techDoc08.html