Today, process plants of all sizes are finding that a wireless sensing infrastructure enabled by a common standard such as WirelessHART can create a framework to support multiple continuous improvement and safety initiatives, with these improvements capable of being implemented very quickly at low cost.
Wireless sensing infrastructure can be used as an alternative or as a complement to wired instrumentation to reduce cost, efficiently manage projects, and reduce the risk of cost escalation.
Start off on the right foot
The first step in implementing a robust wireless network solution is to perform an operational assessment of the plant. Through this assessment, you'll get a better handle on the status of current automation investments and potential problem areas pertaining to reliability, energy, or safety.
[sidebar id =1]The second step is to define an automation roadmap for the site. Implicit within this definition is how technologies such as wireless can achieve a measurable difference in the problem areas defined within the assessment.
Technologies such as WirelessHART are internationally recognized standards that build upon existing HART technology, which is already in common use in process plants. This means the WirelessHART standard is readily accepted and easily integrated into most any automation system, irrespective of the system's age. The user is thus not constrained by the limitations of the site’s existing automation and instrumentation systems.
Address key priorities together
A wireless infrastructure is scalable and flexible, so once it's in place, other operational expense (OPEX) or health, safety, security and environment (HSSE) projects can leverage the initial investment in the wireless network by layering other applications, which can all coexist in the same network. For example, a program to improve compliance to regulatory directives in the monitoring of safety showers can use the same wireless network infrastructure as a heat exchanger monitoring system.
Modernization projects requiring conventional instrumentation upgrades can also significantly benefit. For example, even substituting a few wireless signals on a mostly wired project can deliver significant benefits for the project and into the future. Present benefits are gained when wireless is used to provide access to instruments located in areas, which are difficult and expensive to access with wires. Future benefits are realized by virtue of the fact that once deployed, the wireless infrastructure is there for future projects.
Make the most of the technology
Compared with wired installations, wireless instrument installations are inexpensive, quick and simple. Therefore, wireless infrastructure and instrumentation are often ideal for quickly reducing operating expenses at minimal cost.
The first hurdle to kicking off a conventional wired project on an existing Brownfield site is the sheer complexity of getting all stakeholders aligned and signed up for the required engineering effort. A wireless project, on the other hand, requires minimal support from each department, so interdisciplinary coordination is greatly simplified, and project critical path planning is less onerous. For example, instrument commissioning is not reliant on a whole range of other things being in place such as marshalling panels, junction boxes, conduit, I/O cards, etc. The simplified wireless implementation means the cost and time to deploy is minimal, with installations taking days rather than weeks.
Once in operation, the wireless network can accommodate multiple applications, unlike a wired project, which is typically designed to solve the problem at hand. Ongoing reliability and maintenance is also greatly reduced, as wired instrument installations require periodic inspections as defined in IEC60079 Part 17, while wireless installations do not.
Remember important guidelines
Many process plants have realized benefits by installing wireless instruments and infrastructure for applications such as monitoring heat exchangers, pressure relief valves at flare gas stacks, pumping systems, and steam traps. In many cases, wireless instrumentation can be installed where wired instruments would be too difficult or expensive to install.
Be sure to set up a cross-functional working group to align the organization, define current problem areas and set a road map for functional requirements. Look at manual processes where repeatability and consistency are required for uniform operations, and determine how these can be automated.
In addition, involve maintenance personnel to identify pieces of equipment that cause problems. In many cases, plants rely on manual rounds because conventional instrumentation has been far too expensive to justify considering automating monitoring. With wireless, almost any piece of equipment anywhere in the plant can be monitored for a reasonable cost.
Plants should also put into practice a system of continuous improvements, where manual tasks or lack of information can be addressed through the addition of measurement points. Once a wireless infrastructure is in place, additional projects become easier and less expensive.
Significant benefits can be realized from adopting HART-based technology plantwide. This technology is readily accepted in most every facility because the tools and device interactions for WirelessHART devices are the same as for wired 4-20 mA HART devices. This lets plants focus on the information rather than the technology transport mechanism.
The operational assessment described above can help plants prioritize and justify project budgets previously deemed low-priority or unattainable with conventional wired instrumentation. The assessment also can show how to consolidate projects that enable incremental improvements across multiple areas. Finally, an operational assessment can illustrate how to extend the life of an aging automation system by wirelessly enabling that platform, allowing for an expansion of signals and enhancing the capability to receive additional actionable information through wireless signals.
