Flownex® is the leading software for modeling Heat Recovery Steam Generators (HRSG's) and boilers, additionally utilized for rapid and precise steady-state and transient simulations.


Steady-State Design

  • Analysis of natural circulation boiling sections.
  • Modeling and design of the heat transfer between the gas and steam side of a heat exchanger.
  • Modeling of the complete system, including superheaters, economizers, evaporators, pumps, turbines, etc.
  • Adaptable modeling approach according to the required level of detail.
  • Assists in proper and economical design for the expected operational conditions.


Transient Analysis

  • Determine rates of change in material temperatures.
  • Evaluate control philosophy.
  • Determine plant power ramp rates.


  • Detection of unwanted operating conditions involving:
    • Boiling oscillations.
    • Departure of Nucleate Boiling (DNB)
  • Evaluation of off-design or accident scenarios.
  • Evaluation of temperature gradient during start-up.
  • Evalution of start-up, shut down and load changes.
  • Flow stability analysis.
  • Flow distribution.
  • Balancing of flow in parallel paths.


HRSG web image


Flownex® proved to perform well also for simulations of start-ups (or shutdowns), making it a valuable tool for studying and optimizing such procedures.

Carlo Favalli - Politecnico di Milano - MS Thesis - Eng.