Apros software is renewed to simulate clean power plants of the future

Apros is already widely used for dependable analysis of combustion and nuclear power plants in particular but also of other industrial processes. Even the most difficult process failures can be simulated by using this software. Apros simulation software is the result of a quarter century's development work by VTT experts in co-operation with Fortum, and it is already used in 26 countries.

Apros version 5.09 brings several new features for its end users. The separate phase thermal hydraulics calculation (6-equation model) of Apros has now been extended to cover all parts of the steam and water circuits, including the turbine sector models. Also non-condensable gases can be included in these circuits, enabling e.g. for studies of starting up operations from cold shutdown with only gases in the circuits. Material properties of air and flue gas circuits have been extended to include liquid oxygen, nitrogen and carbon dioxide to allow simulation of oxygen production and carbon capture processes. Apros also introduces a new fluidized bed combustion component that can be used for modeling of both bubbling and circulating bed combustors. Furthermore, the modeling of different types of desalination plants has been improved. Apros is able to simulate accurately multi-stage flash distillation, reverse osmosis and multiple-effect evaporators. Apros provides a large library of blocks for elementary model building enabling the user to graphically specify extensive process component models in detail. Model specifications can be written to ASCII-files using the versatile model specification language of Apros and easily transported to new Apros software versions, computer hardware or operation systems. The specification language enables interconnection of Apros to other design tools and especially to new semantic design databases of both processes and control systems.

Product Manager Janne Liuko from Fortum says: "In Finnish nuclear industry, Apros has been exploited in independent analysis calculations of the EPR plant under construction in Olkiluoto and in designing and testing of new digital automation systems for the Loviisa VVER plants. Other full-scope Apros-based simulators have been developed to replicate nuclear power plants of Russian, Swedish and Chinese design. As well as a design tool for prominent contractors and engineering agencies, Apros is used to train operators and engineers on how the processes and full scale power plants operate."

According to the main designer of the Apros software, Dr Kaj Juslin from VTT, Apros is continuously developed to suite analysis needs of evolving new types of power plants such as clean combustion power plants as well as generation IV nuclear power plants.

The quality of each new Apros version is thoroughly verified and validated. Along the way, numerous end users have given valuable feedback and new goals to the developers. A new software product - Apros Testing Station - will soon be available. It supports easy comparisons of simulation runs to measured transients. It makes the validation and regression testing of new Apros models very efficient. It has also been used for managing the simulation assisted testing of digital automation systems. The Apros Instructors Station software, on the other hand, supports the instructors in training simulator applications to plan new training sessions and to supervise ongoing simulator training.

Source: VTT Technical Research Centre of Finland