Hu also depends on MiMiC to debug programs. “We are batch process, which is sequence-intensive. We put the process online and simulate it to make sure instruments are doing the right thing at the right time.”
Training and Graying
Training is another territory simulation software is staking out in process operations. When more and more trained and experienced workers walk out the door with their retirement packages, new workers without that valuable institutional history and experience need to be brought up to speed quickly.
“Simulation allows us to keep our training current,” says Larry Fedorek, Project Manager for TransAlta. “In this industry, there are always a lot of enhancements and ongoing upgrades and changes to our operating systems.”
To keep up his employees up to speed with these changes Fedorek depends on simulation software. “The essence is to make things as efficient as possible and squeeze every ounce of energy from all our fuels. In order to maintain a high level of expertise within our operations group, we must be committed to keeping [employees] up to date on our system changes. This inherently allows us a better degree of safety from all aspects as well.”
Training new workers is key, says Fedorek. “We mainly use training simulations for new operators. They go through rigorous sessions to ensure they are ready for all situations before even heading into the Main Control Room (MCR).”
Mike Hutchen, TransAlta’s training manager puts it bluntly, “There are a limited number of operating procedures that you can practice in real time. Practicing for an event or an upset to occur,” he says, “is not possible without actually experiencing the event, and we struggled with finding a way to develop people skills for it.”
Fedorek says that running simulations improves operator effectiveness just as Hutchen requires. “If the simulator or simulation is done well, and the instructor gets the student ‘in the zone,’ there is no difference between the simulation and the live system,” Fedorek says. “The instructor runs through almost every possible scenario and upset condition. The operator is much better prepared than learning ‘on the job,’ and this also results in better safety and reliability stats.”
Genencor also uses simulation for training. “It’s a high-fidelity simulation,” says Hu. “For the operator, it looks like the real thing. Basically we use it when we roll over the system. [We have people] learning the real process on old system and the simulated process on new system. It allows people to get familiar with it.
For all their benefits, simulators have a downside. For one thing, getting full benefit from them takes time. “We continue to use the simulation if it is something really major, but not as frequently as I would like,” Hu says. “It takes a lot of time to implement the simulation, and sometimes we simply don’t have the time to do it. It took a good month or two to setup for our DeltaV rollover. It depends of the degree of sophistication, too. As far as verifying sequence goes, you don’t need too realistic a setting.”
Some simulators provide the ability to get feedback, but that takes time too. “One thing about the MiMiC software is the simulator feedback. There’s no I/O attached, so we simulate the field response. For 1000 I/O points, it would take a week to set up,” says Hu.
“Understand that it is not just hardware/software. It takes a lot of resources to implement. You need a big buy-in from management. The simulator is just a tool. You will take a while to get there for good results.”
A way to save some of that time would go a long way toward making “simulator perfect” for Hu. He’d like, “a way that I wouldn’t have to program in the dynamics. Those responses have to be put in. It was relatively easy for me because I had the data. I would say that I’d like a simulator that was smart enough to know the basic thermo and fluid dynamics so that they wouldn’t have to be programmed in.”
Larry Fedorek is also looking for “simulator perfect.” “To me,” he says, “simulator perfect means an operator cannot tell the difference and that includes the actual room he is training or working in.”
While we’re a ways from “simulator perfect” yet, the rewards gained by Lubrizol, TransAlta, Genencor and other companies would seem to indicate that simulators must be worth the hard work.
“Do not sell short the value,” says TransAlta’s Fedorek. “Put in the time to develop a useable and user-friendly system. The initial time commitment required by the owners’ team, in order for the simulation team to do a good job needs to be recognized up front.”
Barry Hu also sees the value and the work involved. “You will take a while to get there for good results. It takes a bit to learn. I can do the low-level stuff pretty easily now. But with hi-fi simulation, we’re not just talking about programming anymore. You need engineering help. You need to understand the dynamics of your process to make the simulation work”
The Kids Get It
In the past few years, training in the use of simulators has become ubiquitous in chemical engineering schools and has permeated the chemical engineering profession. Students are taught the use of simulation software such as HYSYS from Aspen Technology. At Rowan University, in New Jersey, for example, according to a paper “Process Simulators in the ChE Curriculum”, “we introduce process simulators in the freshmen year and use them as a teaching aid in several courses throughout the curriculum.”
Based on the standard chemical engineering process flow diagram, simulators can be used to model widely varying processes. In fact, at Rowan University, freshman ChemE students have modeled the human lung and used HYSYS to reverse-engineer everything from common chemical processes to those found in automatic coffee makers.
When these students move to real plants, they will find that simulators are regularly used for loop tuning, operator training, advanced process control and process optimization.