ProSim DEP

Dynamic simulation of vessel depressurization

ProSim DEP is a depressuring unit operation dynamic simulator.

ProSim DEP allows to:

  • solve the mass and energy balances for all the process unit operations;
  • compute the streams characteristics (flowrate, composition, temperature, pressure, properties) at any point of the installation and overtime;
  • carry out a pre-designing of the main equipment and provide the necessary elements for a complete design calculation;
  • optimize the process operating conditions according to various criteria (cost, manufacturing, environment…).

Main features

  • A rigorous dynamic model
  • Multi-tank systems can be simulated
  • Many options for thermal transfer in tanks (API RP520, fire case…)
  • The contents of an enclosure can be liquid, vapor or liquid / vapor
  • Drains in the upper part and / or in the lower part are supported
  • Flexible configuration of valves and pipes
  • Geometry of the tanks described in detail
  • Complex scenarios can be simulated (description of events)
  • Complete thermodynamic library for representing highly non-ideal systems and a wide range of processes.
    User-friendly graphical interface allowing a simple description of the installation and quick access to the results
  • Easy-to-use and open software

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The depressurization of the tanks is made for safety reasons: to avoid an explosion when a heat source appears (in the event of fire), to drain into the vents network if a leak appears in the installation, in the event of an electrical failure… The problem to be solved is therefore to drain the equipment within a time considered reasonable to avoid any problem in the plant.
ProSim DEP software allows to determine the evolution over time of the characteristics of the depressurized equipment (temperature, pressure, compounds quantity, composition of the phases, flow rate evacuated through the safety valve and its composition, flow through the breach, etc.).


A dynamic simulation environment

The depressuring module allows to determine time-pressure-temperature relationship when a vessel containing liquid, vapor or liquid/vapor mixture is depressured through a relief or control valve. Emptying can be done from the liquid phase or the vapor phase, depending on the different types of flow.


Depressuring module is integrated into ProSimPlus’ dynamic simulation environment

  • Sequential modular approach is used with:
  • A global simulation duration (time horizon)
  • An increment of integration (step duration)



A user-friendly and easy-to-use graphical interface

From your description of the problem, enabled by a quality graphical user interface, ProSim DEP automatically establishes the connection between these programs to carry out the complete process simulation. This architecture presents many advantages: user-friendly environment, flexibility, ability to carry out modifications (more or less sophisticated model, modifications of the diagram…).



ProSim DEP contains two databases:

  • a library of various, effective and accurate physical properties estimation programs and fluid phase equilibria calculations, with access to a database of pure component properties, this library being easily extensible;
  • a mathematical model library of unit operations which is also extensible.


A simple sequence of steps and ease of use of the results

For each equipment, the use of more or less complex phenomenological models makes it possible to consider a progressive approach to the unit to be simulated. In addition, the availability of a wide range of thermodynamic models makes it possible to deal with the most complex systems.

Step 1 – Tank description

Step 2 – Initial conditions of the calculation

Step 3 – Heat exchanges definition

Step 4 – Draining description (liquid and/or vapor)

Step 5 – Stop events

Step 6 – List of predetermined events: the user can define a list of predetermined events

Step 7 – Numerical parameters: the user can modify the default values

Step 8 – Exploitation of the results


Following the start of the calculation, it is possible to follow the evolution of the convergence equipment by equipment or in a more general way on the whole process.

In addition, the consultation of the simulation report is intended to be as interactive as possible since each equipment has its own window for consulting the results. A general summary file in HTML format can also be edited and / or printed.

Finally, exporting the simulation results to Microsoft Excel™ can be done very easily.