[sidebar id =1]Starting up a new unit, facility or control system can be the thrill of a lifetime, even when everything goes according to plan. An operator training simulator (OTS) can contribute to that success by allowing operators to be trained before startup, and providing a way to test and improve the controls. “You can shave off enough startup time to pay for the system – it doesn’t take many days to pay for it,” said Greg Rogers, director of control engineering, Enterprise Products. It also can help you achieve best practices in operations, improve productivity and prevent upsets.
But only if it’s done right. Enterprise Products is a leading North American provider of midstream energy services including natural gas processing, pipeline transportation, storage and marine services. “Enterprise exports more propane than any country in the world, including the U.S., if you take us out,” Rogers told attendees of his session, “OTS: A Safe BET,” on the topic of OTS benefits, execution and traps (BET) at Honeywell Users Group Americas 2016, this week in San Antonio. He recently completed an OTS project on a new system, and while he didn’t go into details about the process, he did say, “If it was just a simple fractionator, we wouldn’t be here.”
Learn by doing
Learning retention studies show that short of actually teaching someone else, the most effective way to learn is by practice, which results in 75% retention. Simulation is a safe way to allow operators to practice. An OTS is a computer-based training system that uses a dynamic simulation of a process integrated into a replicated plant control system. Components include dynamic simulation software, a process model, operator and instructor interface, and control system integration software. Depending on how it’s specified and executed, the combination of operator training and process simulation can help:
- Better train operations staff on the process;
- Train prior to startup
- Give better response to upsets and at startup and shutdown;
- Reduce startup time;
- Increase facility uptime with safer operations and improved reliability;
- Allow refresher training;
- Provide evaluation tools;
- Standardize best practices among operators;
- Improve operating procedures;
- Protect production, prevent equipment damage and avoid environmental upsets;
- Avoid costs of poor quality, material loss and reprocessing;
- Validate control and logic systems; and,
- Debottleneck and test plant operating ranges without upsetting the running plant.
Best practices can improve productivity and increase reliability by retraining “the overcautious control operator who is not making you money, and the one who’s running the plant on the jagged edge,” said Rogers. Well trained operators make fewer mistakes, and “Avoiding a mistake that costs two days of downtime can save a lot of money,” he added.
Simulation also can be used to validate the control logic, tuning and fidelity of the models, and provide a test bed for process improvements. “I can see issues and get them fixed before they affect production,” Rogers said. “We can try out changes to try to relieve a bottleneck without swinging or knocking down the plant.”
Execution starts with a vision
“When you know what an OTS can do, you can begin to develop your scope,” Rogers said. “You can decide what you really want the OTS to accomplish.” Is your vision just to replicate the logic, or do you want to simulate the entire operator environment – the room, the workstation and the chairs? Do you want it to be “kind of like” the operator station, or exactly? What level of training do you want to accomplish, and what level of function (how it looks to the operator) and fidelity (how closely it matches the process) do you need?
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What system will you use – the vendor and architecture? Where will operators access the system from, who will maintain it, and do you need to manage operator competency? The answers to these questions will help define (and largely determine the cost of) the system components, including functional fidelity, model fidelity, interface, software license, hardware and long-term support requirements.
Enterprise selected Honeywell Unisim Operations for its process based on its dynamic model accuracy, instructor capability, process and control simulation, instrument and control system (ICS) interfaces, and trainee evaluation tools. The choice was also influenced by Honeywell’s background in gas processing and fractionation, and its support capabilities. Other selection criteria include in-house capabilities for integration and long-term support, ability to use remote support, and initial, annual, and license costs.
“Answer these questions for both the model and the system, and budget for support because you’ll need it,” Rogers said. “If you’re not going to keep the system up to date with process changes, don’t waste your money buying it.”
Traps can be avoided
Like any project, agreeing on the right scope will avoid many problems, but, “You also need to understand the bill of materials (BOM) – what you’re getting,” Rogers said. “And the vendor also has to really understand what you expect.” Go over the BOM and be sure you agree on exactly what’s included and what it will do.
Consider contingencies. “Our DCS system was delayed, but the operators had to be trained, so we had to break the system into phases,” Rogers said. “It didn’t cost a lot more, but it’s best to consider the possible problems before you ask for the money in the first place. Put in some contingency, and you’ll be all right.”
Before you start, assemble a team with engineering, operations, system and vendor experts. “We put together an awesome team, and you really need these guys. Also, we had Honeywell, ourselves and process licensor all give input on the models,” Rogers said.
“We’re using the simulator now on one system, but our goal is to use it for all of them,” Rogers concluded. “Operations loves it. At first, they were skeptical – they thought they didn’t need it – but when they saw it, they said it’s awesome.”
