TURCK's excom replaces the I/O layer including Ex isolation at Chevron Phillips Chemicals International NV, saving significant space in the I&C rooms
When the I/O system used with the Honeywell control system at Chevron Phillips Chemicals International NV (CPChem) in Beringen, Belgium, was discontinued, the specialists on site identified TURCK's excom as the I/O system best suited as a replacement. To support this, Turck Mechatec prepared fully prewired control cabinets with excom racks and dedicated marshaling panels for CPChem, which were commissioned in a very short time. Today, excom saves significant space in the instrumentation and control room because it integrates the separate explosion protection barriers that previously occupied a large amount of space. In addition, all excom systems can be operated in the same way, regardless of whether they are installed in Zone 1, Zone 2 or the safe area.
Anyone who has followed the technology and IT press closely may have read the obituaries for the smartphone a few years ago. Its time was supposedly up—most recently, prominent Silicon Valley CEOs predicted as much. Frequently cited successors include smart glasses, smartwatches and digital assistants such as Amazon's Echo with the Alexa assistant, as well as similar devices. When technologies transition, they create room for innovation. In this respect, consumer and B2B business are alike: when existing device types are replaced or become obsolete, their function—what they provided for a plant or machine—has to be taken over by another device.
Seen in this light, brownfield projects in the chemical industry can be viewed the same way. At petrochemical group Chevron Phillips Chemicals International NV (CPChem), TURCK's excom now replaces the previous I/O system and the formerly separate Ex isolation in a single enclosure. This frees up space in the I&C room, creating room for plant expansions and innovative technologies. The Beringen site has been part of CPChem since late 2011 and was founded in 1991 by Finnish refining company Neste. Polyalphaolefins (PAOs) are produced in Beringen and used in synthetic oils and lubricants, and customers for these oils include the automotive industry and other industrial sectors.
In 2013, the Finnish manufacturer discontinued the I/O system for the Honeywell control system used in Beringen. CPChem's responsible technicians therefore began looking for alternatives. They needed a system that could be connected to the Honeywell control system via Profibus DP and that would provide Ex isolation of the signals—i.e., supply both intrinsically safe and non-intrinsically safe devices. In addition, the system needed to be flexible and support modern diagnostic capabilities and open standards. The new I/O layer also needed to occupy as little space as possible and not affect plant availability.
CPChem approached control system manufacturer Honeywell, which proposed TURCK's excom I/O system as a replacement solution. Honeywell and TURCK have already demonstrated their strong collaboration worldwide on numerous projects—both in terms of the teams involved and the systems deployed. In addition, CPChem researched other potentially suitable systems independently.
"A major advantage was that we were able to carry out much of the preparatory work in advance. After that, we were able to proceed with plug-and-play, since we didn't have much time. The actual installation took just one to two days."
Sarah Gyssels | Ingenieurin | Chevron Phillips
CPChem initially implemented a pilot project with a single control cabinet, in which the I/O cards were replaced by an excom subrack. These were intrinsically safe signals for field devices in Zone 1 or Zone 2. Since the experience in the pilot project was positive, the follow-on projects were also planned with excom. The first takeaway from the pilot project: excom saves a lot of space. Other systems require separate Ex isolation for signals in Zone 1. With excom, signal processing and Ex isolation are integrated in a single enclosure. After the pilot project, CPChem realized that instead of five control cabinets with devices from the old system, only three control cabinets with excom were required.
After the successful pilot project, CPChem replaced a total of 172 I/Os in 2015. The space-saving benefits of excom were fully utilized, and the I/O card replacement was planned in such a way that entire control cabinets became unnecessary. That space is now available for plant expansions or the installation of additional equipment. In a follow-on project in 2017, additional I/O cards for 720 signals were connected via excom.
Time for installing the I/O technology was tight. Although the plant in Beringen is overhauled every two years within a 14-day window, that period is not limited to physical installation. The devices also have to be thoroughly tested during operation and as part of the overall system. A major advantage was that TURCK was able to deliver fully prewired control cabinets equipped with excom and special marshaling distribution blocks that CPChem had already been using. TURCK's in-house provider for custom solutions, Turck Mechatec, built the control cabinets prewired and ready to connect, including the marshaling blocks. This significantly reduced CPChem's installation time, since all field wiring could be retained.
A CPChem contractor only needed to position the control cabinets and land the wires on the correct terminals. "A major advantage was that we were able to complete much of the preparatory work in advance. After that, we were able to proceed with plug-and-play, since we didn't have much time. The actual installation took just one to two days, but testing follows afterward," says engineer Sarah Gyssels, who then explains the site acceptance test (SAT) and the factory acceptance test (FAT). While the FAT was performed at Turck Mechatec before installation, the site acceptance test had to be carried out at the plant after installation. This often takes longer than the installation itself.
By 2019, the complete migration of the I/O cards—including non-intrinsically safe signals—is scheduled to be completed. At that point, all 2000 I/Os will be connected via excom. Having all signals, whether intrinsically safe or not, connected through the same system makes operation easier for plant personnel. The excom systems for Zone 1, Zone 2 and the safe area use the same GSD file and the same DTM. As a result, employees work with a single logic and a single user interface to operate the system. HART communication is not currently used at CPChem, however it is important that excom is HART-capable to be prepared for future expansions.
Unlike many other systems, the individual channels of a module are galvanically isolated from one another. In the event of external interference, such as electromagnetic radiation, this ensures that interference is not transferred to adjacent channels. Overall, this results in more reliable measurements. Short circuits on one channel also have no negative impact on the other channels of the same module.
Anyone who has ever been involved in a retrofit project of this size knows that issues will always crop up. Therefore, the key question for CPChem was how TURCK handles such problems. "TURCK resolved the issues that arose quickly," says Sarah Gyssels in retrospect. "We always had contacts who genuinely took ownership. The on-site training at TURCK was also very helpful for us, because now everyone is on the same page—including the new team members."
User | www.cpchem.com
Project partner | www.honeywell.com
Danny D'Hollander is a sales engineer at Turck Multiprox in Belgium
Turck Mechatec provides mechanical and electrical system solutions tailored to customer specifications for all areas of industrial automation technology. Whenever customers want more than just standard solutions, that's where we come in.
