New technologies to achieve refinery modernization objectives: Laser Scan Surveys, SIS/HIPS, and Arc Flash Reduction

Ambitech

Ambitech Engineering Corporation (Ambitech) has completed highly complex and logistically challenging refinery revamp, upgrade, and modernization projects at a large number of international and domestic facilities over the last quarter century.

Ambitech routinely uses state-of-the-art technologies to improve the design engineering process itself as well as its sequencing to optimize the installation of the final design in the field. It is through these efforts that Ambitech is able to consistently help facility owners achieve significant, long-term benefits.

Given the compressed timeframe in which many refinery upgrade programs must be completed, it is imperative that the design engineering process be as efficient, cost-effective, safe, and accurate as possible. One of the new technologies being utilized to attain this objective is the use of laser scan technology. This application allows the designer to accurately identify the tie-in locations of the existing system to be revamped without the need for laborious and possibly dangerous field measurement.

Because the single most important strategic goal of most modernization programs is to maintain high-capacity and uninterrupted process throughput while maintaining safety, the implementation of technologically advanced Safety Instrumented Systems (SIS) and High Integrity Protection Systems (HIPS) is now playing an increasingly important role. As refinery processes are being expanded, the need for relief valve venting is causing a problem with existing flare relieving capacity. Costly flare expansions and equipment downtimes are being considered as a result. Ambitech has helped refineries save money by avoiding these flare expansions by implementing HIPS, which have a reliability equal to or better than traditional relieving means.

Finally, as existing refinery process systems become increasingly strained to expand output, the use of arc flash hazard analyses to help minimize the likelihood of arc flash occurrences and resultant facility disruptions are also in need.

As existing refinery infrastructure continues to age, the use of new technologies that improve engineering design data and processes and ensure upgrade and modernization program objectives are achieved in the shortest amount of time in the safest manner is rapidly becoming a strategic necessity. Ambitech works within this environment, understands these objectives as a matter of standard practice, and employs technologies to help assure these successes are attained.

Laser Scan Technology

As-built documentation generated from laser scan technology is quickly becoming the tool of choice for project teams tasked with revamp and upgrade projects. Laser scanning, which replaces current line-of-site surveying techniques and equipment, reduces costs, improves quality and shortens schedules. Laser scan data is also the foundation for the development of an as-built 3D model of the specific area within a refining facility that is targeted for the upgrade or revamp.

Laser scan data shows the existing points of the process systems within a refinery, allows for the selection of the exact pieces of those processes that will be part of the upgrade, and allows for the design of those components in a value-added 3D environment. With improved data and 3D modeling to enhance the mechanical and structural engineering design of the upgrade or revamp, and the ability to take the generated isometric drawings into the field for and during construction, facility owners can be assured that office design work can be brought to and constructed in the field in the least amount of time and cost.

As suggested above, laser scan technology is a value-added application that reduces refinery revamp and upgrade costs for the current effort as well as future modernization programs. Costs in the field for data collection are reduced, construction rework and field changes are minimized, and the as-built and readily transportable laser scan data and resultant 3D model is available for future projects. A reduced field schedule is beneficial for several reasons. First, it provides the project team with valuable data sooner so that engineering and design options and decisions can be evaluated and executed earlier in the upgrade program. Second, it minimizes the amount of time workers need to be in a potentially hazardous environment.

Laser scan data, and the way in which it is collected, enhances quality without increasing a project’s cost. Because of the congested and complicated layout and hazardous environment of most refineries, traditional line-of-site surveying challenges the most experienced personnel in their efforts to collect accurate data. Accurate data collected through laser-scan practices leads to improved quality and more informed decisions regarding construction, start-up, safety, and maintenance.

Many modernization, upgrade and revamp efforts are scheduled during refinery turnarounds where the window of opportunity to complete project construction and the work leading up to that point is often small and firmly established. Laser scan technologies help minimize this schedule by reducing the amount of time needed in the field for data collection. Additionally, since the data generated is subsequently used in a 3D model, the design engineering schedule is compressed as design efficiencies are achieved.     

Because the collection of laser scan data requires fewer individuals than traditional surveying techniques and because the data can be collected in fewer work days and with fewer trips, the number of people and time spent in potentially hazardous environments reduces the opportunity for an accident to occur.

Combining all of the above positive attributes, Ambitech has employed laser scan technology and 3D modeling at several refinery facilities including a recent HF Alky unit upgrade project for a client in the United States. For this particular effort, under previous technology applications, a significant number of workers would have been required to suit-up to enter a restricted, hazardous area of the refinery over a three week period to locate and take dimensions of existing equipment. Instead, laser scan technology was employed. The work only required a few workers and the task to take an electronic snapshot of the entire area of the facility to be impacted by the upgrade was done in a single day. This streamlined, more accurate technology minimized risk, generated cost savings, and reduced the project’s schedule by nearly three weeks. Additional time savings were attained because, as the 3D model was constructed, the laser scanned data negated the need to go back into the field to reconfirm or gather additional data. With the 3D as-built model generated, it was a relatively simple step to place all of the new structures, equipment, and piping in the best possible location within the site’s many physical constraints. An added benefit of the 3D as-built model was that it met the request of government agencies for detailed renderings to assist with their inspection work.

SIS and HIPS

Ambitech Engineering Corporation has experience in process instrumentation and controls upgrades at refineries including triple-redundant Safety Instrumented Systems (SIS) and High Integrity Protection Systems (HIPS). SIS, an integrated system of sensors, logic solvers, and final control components that functions independently of any basic process control system(s), takes the targeted process or processes to a safe state once predetermined conditions are compromised. HIPS is a SIS with the same function and objective, but specifically relates to vessel or pipeline overpressure prevention in lieu of a pressure relief valve (PRV).

HIPS technology is becoming the option of choice to reduce the need to replace flare systems in existing refineries when new equipment and/or units are added. Often, the capital and installation costs associated with HIPS are attractive when compared to the downtime and equipment costs associated with flare modifications. Another benefit of HIPs is that the process unit often will not need to flare as much as one designed for full flare loading. This is of particular value to refineries located in regions of the world with more restrictive environmental requirements.

SIS and HIPS, particularly as applied in a reactive environment, can help refinery facilities achieve modernization and upgrade objectives established to achieve uninterrupted facility throughput. This is of particular value in situations where the acquisition of an expanded environmental permit is not probable. Additionally, in many reactive environments, the use of a pressure relief valve is not practical and therefore, other methods to prevent overpressure scenarios must be employed to achieve risk reduction. Specifically, pressure relief valves can be ineffective when the reaction:
•    generates materials that block the PRV;
•    occurs in a localized area at a rapid pressure or temperature rate such that a PRV cannot react or internal detonation/fire occurs prior to PRV reaction;
•    generates pressure at an uncontrollable rate such that a properly sized PRV is not possible.

It is in these situations and others that a Safety Instrumented System can be established to achieve a high enough level of safety availability to exceed conventional design. Prior to implementing any HIPS, a quantitative and/or qualitative risk analysis of the proposed system must be performed to identify and address credible overpressure and/or over-temperature scenarios. The result of this analysis must be the demonstration that the proposed SIS or HIPS is completely independent of the potential causes of overpressure and/or over-temperature, that it is at least as safe or safer than a pressure relieve valve, and is completely capable of mitigating any overpressure event.

As laser scanning technology has positively impacted the design engineering process itself and the output of the mechanical and structural design effort, SIS and HIPS have significantly improved the process engineering’s task to further increase refinery efficiency, enhance safety, and maintain uninterrupted output. These technologically advanced systems allow facility owners to more effectively lower the risk of production stoppages in areas of the refinery previously unavailable due to existing and limited technologies and designs.

Ambitech has significant analysis, evaluation, design and installation experience of Safety Instrumented Systems in a wide variety of refinery environments and units. Several recently completed projects include:
•    a SIS system engineered to shutdown process feeds to prevent releases to the environment and redirect reliefs to the flare
•    a SIS system and specified emissions analyzers, O2, moisture, CEMS, CO analyzers
•    BMS and combustion control, SRU Incinerator at tail-end of process, and specified redundant fuel gas pressures and temperatures, instrumentation and controls
•    triple-redundant hardware and control system architecture for Plant Deluge System driven by cameras for water spray system for safety containment of HF release on a HF Alky Unit.

Arc Flash Hazard Reduction

As refinery owners strive to increase production within their aging facility through a variety of means, a new and rapidly expanding point of attack to maintain consistent production throughput is to address, and ultimately improve, the facility’s electrical distribution systems.

In an arc flash incident, enormous amounts of concentrated radiant energy catastrophically explode outward from electrical equipment creating pressure waves, a high-intensity flash, and a superheated ball of gas that can severely injure workers and damage adjacent equipment and structures. Within a refinery, an arc flash incident can occur in any electrical device, regardless of voltage, including panel boards and switchboards, MCCs, transformers, and motor starters and drive cabinets

Ambitech works closely with clients during all phases of an Arc Flash Hazard Analysis project. Since the adequacy of a refinery’s electrical distribution system model (from which failure scenarios are run) is dependent on the accuracy and detail of single-line diagrams, it is necessary to commit qualified personnel to collect the data needed to create, verify, and update the facility’s single-line diagrams. Once the electrical system model is generated and failure scenarios are run, cost-effective measures and/or state-of-the-art equipment are identified to negate some or all of the need to have facility employees in full Personal Protective Equipment (PPE) as they conduct their typical job functions. Such measures help increase productivity and maintain consistent production volumes while meeting safety objectives.

Conclusion

For refinery upgrades, revamps and modernizations; the need to utilize the latest state-of-the-art technologies to (1) reduce cost while increasing the efficiency, safety, and accuracy of the engineering design and modeling process; (2) achieve the refinery owner’s modernization and throughput objectives, and (3) minimize process disruptions, is as critical as ever as refineries in many parts of the world begin to age. Modernization programs are particularly time sensitive and can be disruptive to a facility’s operation and as such, need to be done as quickly, safely, and cost-effectively as possible while attaining the facility and process gains demanded. Ambitech Engineering Corporation remains committed to the value and benefits that new technologies can deliver to our worldwide clients and continues to seek out and use those technologies that make our work ever more value-added.

For more company information, please visit www.ambitech.com.