Dynamic Process Simulation

​Apros is a simulation software product developed by VTT and Fortum. Since 1986, Apros has been used for simulation of combustion and nuclear power plants, but Apros is also used for dynamic simulations for other industries, for example in pulp and paper mills, desalination plants, solid oxide fuel cell systems, district heating and cooling network simulations and recently also for solar power (PV and CSP). To the end users we provide Apros licenses as well as training, expert consultation and software integration services. In these services we can involve top experts from the product development organization.

Apros includes a comprehensive library of component models such as valves, pipes, pumps, tanks, measurement devices and controllers. Using the versatile library of automation functions, it is easy to model measurements and controls, as well as interlocks and sequences. AC/DC systems can also be modelled. The user can create his own device modules using model components and also specific custom codes. User components can be included in the calculation and reused later in other simulation models. The new Apros version 6 provides a user-friendly modelling environment and some advanced tools, such as an OPC UA interface for effective simulation data transfer and a high level SCL programming environment.

Apros simulates systems by solving dynamic mass, energy and momentum balances, all balances being solved for every simulation time step. In addition, empirical correlations can be used, for example for heat transfer calculations. Apros offers several alternative thermohydraulic calculation models responding to the varying needs of modelling in different parts of the process and for different modelling applications. Calculation models are verified using physical test cases and also against data of measurements made from existing plants.


P.O. Box 1000, FI-02044 VTT, Finland
Tel. exchange +358 20 722 111
Opening hours Mon - Fri 8:00 - 16:30,
UTC +2 time zone


Tel. +358 20 722 7070
Opening hours Mon - Fri 9:00 - 11:00 and 12:00 - 15:00,
UTC +2 time zone