Maintenance: An extra spurt of effort for full power
Gas turbine #2 at the Pesqueria Power Plant has just passed its first major inspection, which will allow it to continue functioning in tip-top condition. A close-up look into the heart of the turbine, six years after startup.
The Pesqueria Power Plant, which has been supplying energy since 2016 to the main industrial plants of Ternium and Tenaris Tamsa in Mexico, has just been overhauled as part of a major maintenance shutdown process. The aim is to ensure it can continue to produce electricity in optimal technical conditions.
The last maintenance shutdown was performed on gas turbine #1 (GT1) in September 2021, so in May this year, it was GT2’s turn. The service is carried out every 48,000 hours of machine fire and involves a temporary exceptional effort from our own resources and a team of specialized contractors. The remit is to carry out a full inspection and repair routine, including part replacements, as efficiently as possible to minimize the time involved, as the plant can only produce two-thirds of its usual electricity output while the stoppage lasts.
Over 300 people were involved in this latest effort, which lasted nearly thirty days, working around the clock in shifts, although planning for this operation began as much as eighteen months earlier. There were many conditions to be set, including, first and foremost, the need to follow a set of strict protocols. Alma Rivera, the plant's operating engineer, told Tecpetrol Hoy about the different roles and responsibilities and explained that hers was to “manage synergy between our own staff and contracted personnel, always in compliance with our quality standards (the Quality Plan Checklist) and within the deadlines set.”
During the shutdown period, Alma was at the helm during the night shift, which meant a radical change to her routine, built around her tasks of monitoring critical goals. “I had to be fully up-to-speed with all personnel permits and schedules, keeping track of all the activities going on in order to avoid delays,” she explained. In reference to the company’s protocols and policies, she emphasized that "for us, safety is of the utmost importance and thus a priority throughout our work."
As regards the maintenance of the gas turbine, one of the main tasks during the shutdown was a thorough review of the rotor which is considered “the heart of the plant.” This involved removing all the casings and performing a close-up visual inspection, as well as a detailed examination of the compressor and generator, all of which were performed together with an expert technician from the supplier, General Electric.
"Our experience in 2021 meant that this time around, we were able to manage the timing more efficiently and return to full-load production earlier," Rivera explained. "On this occasion, the shutdown period ran from April 25 to May 23, which was less than the thirty days we’d originally envisaged when drawing up the schedule."