In recent years, steam systems have improved their energy efficiency but have become increasingly complex, integrated and interactive. While such steam system designs provide for optimal steady-state operation, they tend to limit the transient capability of a plant and have a negative impact on variability.
Enero Steam Simulators can troubleshoot complex multivariable steam systems. Control strategies and tuning parameters derived using this first-principle simulation and process models have typically proven to be so accurate that no significant tuning or control changes are required during startup.
Our steam simulation is based on the non-linear nature of thermodynamics and uses steam and water tables as the only tool to convert state variables to process variables. Using steam tables together with local mass and energy balances makes the simulation design more complex but results in a more accurate model. Because a steam system is highly coupled, thousands of blocks and dozens of differential equations are simultaneously solved by this simulation using numerical analysis techniques.
Enero Solutions regularly designs first principle simulations of steam-water systems and provide the following benefits:
Minimize the time required to configure, troubleshoot, tune and optimize the control logic during the commissioning phase of a project
Help plants design the best control strategies for specific dynamics and process load disturbances
Help to understand the dynamics of future steam systems and to change the operation of the powerhouse to load disturbances
As an example of a steam process simulation, Figure 2 shows the effect of a rapid change in the turbine governor valve position on the throttle pressure of a subcritical power boiler:
- When the boiler energy inventory is high, the system has a higher thermal inertia and can provide extra energy while minimizing the variations in throttle pressure and temperature
- When the boiler energy inventory is low, the system has a lower thermal inertia and can only provide extra energy by decreasing the steam pressure