May 2019

Columns

Power: Temporary power tips for turnarounds and maintenance activities

Maintenance activities and turnarounds often prove challenging to a facility’s electrical power system.

Smith, B., Aggreko Process Services

Maintenance activities and turnarounds often prove challenging to a facility’s electrical power system. Such work might vary from a relatively short duration (2 d–7 d) for production curtailments, such as power equipment repairs or inspections, to turnaround extensions focused on a long timeline, such as critical-path electrical system work.

Temporary critical-power utilities address these complex issues to keep the tight schedule, and, most importantly, keep the facility’s personnel and contractors safe.

Early plans a prerequisite

To ensure a safe and less stressful project, prepare crucial aspects of temporary power generation  12 mos before the scheduled turnaround or maintenance start date. Pre-plans prevent issues that might extend the time frame and cost of a turnaround or raise safety risks to personnel.

Pre-plans outline the refineries’ and petrochemical plants’ electrical needs (e.g., operating voltage, power and other electrical parameters, the load and type of equipment) to keep a plant steady. Pre-plans help design the most efficient temporary power system for a specific turnaround. Flexible temporary power equipment avoids either too little power or too much power as project needs evolve.

Update proper safety labels

Electrical hazards make accurate labels for electrical equipment and panels a necessity for plant safety. Inaccurate labels on temporary electrical equipment and panels—even the smallest panels—present a difficult situation for plants and may result in severe injury or equipment damage.

Update temporary electrical equipment with arc flash decals that list the required level of flash and shock protection. Proper labels allow plant personnel to understand system configurations and assess personal protective equipment requirements quickly.

Know fuel options

Pre-plans help determine the best fuel options, as well. For example, prior to a large-scale turnaround at a US refinery, the plant wanted to limit nitrogen oxide (NOx) emissions from the diesel generators. The refiner switched to natural gas as a fuel source, which reduced NOx emissions by more than 80%, while saving $250,000 in diesel fuel costs. This also avoided the logistical challenges associated with frequent diesel fuel deliveries to the facility.

Pinpoint locations and cable routing

Before the project, determine the optimal placement of generators and cable routes in the facility. Layout drawings made through online maps or computer-aided design (CAD) software programs provide plant engineers with a thorough understanding of the proposed location of equipment in the facility. Options include a site-to-site power configuration or, for more significant turnarounds, a distributed, mini-grid style power supply.

Create one-line diagrams

Prior to a project, create a detailed one-line diagram for the plant’s electrical power needs. These diagrams identify the type, size and location of all generators, circuits, and panel and cable sizes to ensure that equipment goes to the right positions and life-critical systems stay active in case of faults.

These drawings save up to 20% in labor costs and the time associated with equipment moves.

Maintenance service and refuel access

No matter the generator selected, all generators require periodic maintenance and refueling on a scheduled basis. A plant must install two generators, rather than one, for backup purposes to keep the facility operating.

To avoid power disruptions, organize each generator’s fuel needs and options in advance. Unfortunately, some plants overlook this aspect of critical response planning and then face power shortages at a site, or across the whole plant, as the plant waits for a refueling truck to arrive. If possible, utilize the generator’s onboard remote monitoring service and associated smartphone app to receive low fuel alerts.

Secure the site and identify critical contacts

As with any high-voltage electrical equipment, temporary generators and cables in a plant pose risks. To increase safety, fence the temporary power generators, anchor the cables and give only trained and qualified personnel access to the area.

Plant management also should prepare a list of key contacts to reach in case of an emergency. These contacts include plant personnel who will be responsible for onsite electrical equipment, as well as representatives from any contractors or vendors that work with the plant to support its electrical needs.

Keep interim power needs a priority to achieve a higher level of efficiency in turnaround operations, enhance workplace safety, minimize congestion in core work areas and reduce operating costs and emissions. HP

The Author

Related Articles

From the Archive

Comments

Comments

{{ error }}
{{ comment.comment.Name }} • {{ comment.timeAgo }}
{{ comment.comment.Text }}