Modifying unique site configurations can rapidly introduce a host of complications and uncertainty. TRAX Energy Solutions can provide a dynamic engineering study to optimize plant operation and control logic for a variety of clients and specialized process types.
See how TRAX helped a client determine the impacts of a process change and provided recommendations to improve plant behavior
TRAX was retained by a client to examine the impact of adding a gas turbine and associated ductwork and dampers to two existing ethylene cracking furnaces. To predict the behavior of the future configuration during a gas turbine trip, TRAX built high-fidelity process and controls models to examine both the steady-state and dynamic behaviors of the plant. The steady-state analysis highlighted issues such as incorrect fan sizing, control set points, and excess O2 control. The dynamic analysis provided insight into how the system responded to unexpected events and showed that it was possible to smoothly transition to ambient air combustion without tripping the furnace on a gas turbine trip.
In the client’s model, the future configuration was established with the gas turbine discharging into the ethylene cracking furnace. The hot exhaust gas was added to the ambient combustion air and the gas turbine was used to augment the electrical load of the plant. The model predicted temperatures at the furnace radiant coil outlet and the convection section outlet, as well as associated dynamic radiant and convective heat loads. The control system was tuned to run to steady-state as effectively as possible. Once tuned, the control system achieved steady-state within five minutes.
The control system response was analyzed, looking for issues with pressures, flows, and excess O2, during the dynamic event and in the resulting steady-state condition. Based on the results of these analyses, TRAX formulated and tested an alternate set of control logic that allowed for a smooth and efficient transition to ambient air combustion and demonstrated these TRAX-proposed controls to the client. Several key changes —outlined below — improved the plant response.
TRAX can help clients address a number of concerns for a variety of process types and unique or unusual configurations.
Thermal Stress
Heat generated by the gas turbine can add stress on the furnace. A study can include a focus on the thermal stress of the boiler and turbine. Reduced thermal stress leads to better availability.
Damage Prevention
Good controls help avoid situations that include the possibility of equipment damage. This includes conditions like turbine differential expansion excursions and steam temperature excursions.
Environmental Compliance
TRAX can optimize controls to prevent or reduce the occurrence of certain conditions, such as venting through bypass stacks or bypassing environmental equipment in emergency scenarios.
Control/Process Test Bed
With a study, it is possible to test control systems before adding them to a live unit. They are a valuable tool for testing new controls.
Agility in Startup and Shutdown
A study can be used to reduce stress on equipment and increase ramp speed during startup.
Heat Rate Awareness
A study can be used to examine heat rate in different scenarios. Promoting savings in fuel helps the environment and economics of the unit, both crucial to long-term sustainability.
A TRAX study can help protect vulnerable equipment by predicting and mitigating severe pressure and temperatures during transient events. A study will also present recommendations for the best future configuration and suggestions for controls improvements of plant operation.
By addressing potential risks from a position of knowledge, plant owners can successfully leverage the benefits of making process changes while mitigating potential risks effectively. These studies can be especially useful for new technologies or complex process types, such as…
TRAX has delivered a carbon capture simulator for a 150 MW coal-fired unit that models the capture of the full flue gas stream. The system provides both CO2 and SO2 capture, delivering the captured CO2 to a pipeline for industrial use and underground storage.
—CO2 and SO2 capture
—Sulfuric acid plant
—CO2 and SO2 amines filtration and purification
—CO2 compression
—CO2 pipeline and cavern
As shown below, TRAX built a modular simulation replicating the plant layout using our software, ProTRAX. ProTRAX contains a full suite of modules specific to carbon capture functions and can model a wide variety of processes. TRAX also virtually replicated the user interface that appears in the plant.
Upon initial delivery, the TRAX simulator was used to debug control logic and processes prior to site installation and to provide operations training prior to plant startup. There was a clear need to begin training operators as early as possible since they had multiple unfamiliar systems to learn.
Thanks to the ProTRAX simulator, our customer gained considerable insight into control functionality and system interactions, resulting in modification to some control logic and correction of simple errors. TRAX was able to assist with controls tuning, and helped in development of initial plant Operating Procedures.
The latest upgrade brings the model into alignment with the as-built plant condition by updating and tuning the simulator models to match the current plant dynamics. In addition, TRAX has updated the simulator controls and HMI graphics to the as-built state. Keeping the simulator aligned with the current plant condition is critical to maintaining a positive training value, and is of paramount importance to the customer.
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