Refineries, petrochemical and other process plants face similar challenges in daily operations, as each facility must mitigate risk, anticipate maintenance, optimize operations and minimize operational expenses. To achieve these goals, plant personnel rely heavily on data to drive decisions.
The excitement around the Industrial Internet of Things (IIoT) is its ability to deliver this data at lower cost and in greater volumes than ever before. This is accomplished when IIoT implementations take advantage of advancements in the areas of wired and wireless sensors, networking and data storage technologies.
The driving forces for these innovations are declining costs and increased connectivity options, enabling plants to measure far more parameters of interest, many of which were too expensive to monitor with older solutions.
Most of these sensors will be connected to a plant's existing regulatory control or asset management system. Wired sensors with 4-20mA outputs require spare inputs on these systems, but many newer sensors and instruments will use field bus digital communications, simplifying wiring and lowering costs.
Wireless sensors can be connected to a plant's control or asset management system via a gateway. The sensors connect to a gateway that is hardwired to the host, usually via an Ethernet connection, eliminating the need for additional input points.
Access to this data by engineers and plant management may be enabled worldwide to anyone with intranet or internet connectivity and proper security credentials. The proliferation of high-speed Wi-Fi and cellular networks has made this type of connectivity ubiquitous and reliable.
However, collecting, storing and disseminating data is just the starting point for IIoT implementations. Process and reliability engineers, often referred to as subject matter experts (SMEs), must analyze this data and derive results to provide operational guidance.
This is best accomplished by using advanced analytics software to connect to the myriad of data sources. The right software is a very effective tool in the hands of SMEs, enabling them to create and share insights using a workflow process, as shown in FIG. 1.
The following examples show how advanced analytics software can be used in refineries and petrochemical plants to improve operations.
Preventing vessel brittle fracture.
Vessels in refineries and petrochemical plants require scheduled inspection and maintenance because many different factors can cause degradation of vessel integrity. A major risk requiring attention during transient operations is brittle fracture.
Brittle fracture occurs when a vessel experiences high stress, such as elevated pressure, without being sufficiently preheated. The minimum temperature at which a vessel can withstand pressure is often represented by a minimum allowable temperature (MAT) curve plotted on an x-y diagram, with pressure on the x-axis and temperature on the y-axis. Awareness and careful monitoring of pressure and temperature during vessel heat up and cool down can mitigate risks of brittle fracture.
Plant personnel often use the MAT diagram appropriate for a piece of equipment given its metallurgy, and transpose these as limits, particularly for startup and shutdown procedures.
A better approach is to use advanced analytics software to convert the relationship between pressure...