Digital twin simulation technology enables many opportunities to improve process and plant personnel performance. In an Intech article, Digital Twins for the Virtual Plant, recently retired from Emerson’s Greg McMillan shares how this improved performance is possible. Here is the article’s opening.
We have exceptional opportunities offered by today’s automation system capabilities to meet the needs and challenges of sustainable and productive plant operation. Smart instrumentation performance and intelligence and the increasing capabilities of control algorithms, data analytics, diagnostics and simulation to deal with a wide spectrum of process situations offers incredible possibilities. This is particularly important considering increasingly prevalent control expertise retirements, tighter budgets and schedules, and equipment and professionals stressed to perform beyond original expectations.
Greg describes the relationship between the virtual plant and a digital twin.
A virtual plant is a software model that encompasses all the latest capabilities in an adaptable real-time simulation that includes the dynamic responses of the process, the equipment and automation system. The digital twin sets up the understanding required to import the configuration and files that are used by the actual plant. The digital twin setup and use are normally within the functional realm of experienced process control engineers. Many can help improve and connect dynamic simulations. However, the models and advanced control tools related to virtual plants are more likely developed by specialists.
He explains the functional value of this technology by:
…highlighting the bidirectional flows of the control system and process/equipment knowledge of process control and analysis tools, including online key performance indicators (KPIs) and real-time accounting (RTA) metrics for greater analysis and justification of improvements. The two-way knowledge flow is the key to improving the process/equipment and the control system in addition to the dynamic model and data analytics.
The virtual plant consists of the actual operator graphics, alarm system, trend charts, and batch & continuous control configuration, all on a DCS workstation or virtual computer on a server. Dynamic process models and online data analytics are embedded modeling tools. Online process metrics and model predictive control are embedded advanced control tools. Coming in and out of this virtual plant are control knowledge & associated online metrics and process knowledge & associated online metrics.
Greg notes that the:
…most familiar use of a digital twin is for testing and training. To check out batch sequences and train operators, it is important to be able to simulate batch phases repetitively and rapidly. The ability to stop, start, save, restore and replay scenarios and record operator actions is critical.
Digital twin technology offers:
…flexible and fast exploring => discovering => prototyping => testing => justifying => deploying => testing => training => commissioning => maintaining => troubleshooting => auditing => continuous improvement showing the “before” and “after” benefits of solutions from online metrics.
Read the article for more on how this technology enables continuous performance improvements, excellent opportunities for application, and how it could be applied to a bioreactor system as an example. For further depth on this application, look for Greg’s book, Advanced pH Measurement and Control: Digital Twin Synergy and Advances in Technology, fourth edition, ISA 2023.
