LAHORE: The 747 megawatts combined-cycle Guddu power plant is all set to be upgraded to Advance Gas Path (AGP) — a modern technology meant for a massive reduction in the scheduled annual maintenance of such projects.
The technology is expected to enhance efficiency and generation capacity of the plant by 1 per cent and 5pc respectively, Dawn has learnt.
According to Muhammad Imran of Gencos Holding, the total cost of shifting the plant to this technology is $72 million.
Mr Imran said the reason behind going to the AGP technology was that the Hot Gas Path Inspection (HGPI) of the plant required parts’ replacement, maintenance and other works. “So we thought to better go towards upgradation of the plant with AGP provision if it costs a little more than the charges of HGPI. Therefore, we finally negotiated with the supplier (GE) that agreed to receive the total cost of the AGP in 16 quarterly instalments,” the official maintained.
The former premier Nawaz Sharif had inaugurated the gas-fired plant in April 2014 after it was completed at the cost of about Rs60 billion. Initially the project had been commissioned in simple cycle with operation of its two gas turbines (243MW each). However, its capacity increased to 747MW at a later stage after installation of the third turbine (steam turbine), enabling the plant to run in combined cycle mode.
Official sources said that the existing technology demands outages of the plant after every 8,000 hours (one year) for completion of the maintenance cycle. But after switching to new AGP technology, the plant will require various maintenance related jobs after every 32,000 hours (four years).
“The current maintenance cycle of the plant involves various inspections, tests etc. Under this cycle, this plant requires to be shut down after 8,000 hours for first combustion inspection (CI). It further requires for another CI after next 8,000 hours and for next three years (24,000 hours), it requires similar inspections, including one related to gas after every 8,000 hours. And finally, the plant needs the final major inspections after 48,000 hours. It is the complete maintenance cycle of such plants,” a senior official explained while talking to Dawn on Tuesday.
For such inspections and tests, the plant—a project of the Central Power Generation Company Limited (CPGCL/Generation Companies-II)--was required to be shut for a period ranging between 10 and 20 days, the official who requested anonymity added.
Talking about the AGP technology, he said the plant machines could easily be upgraded/converted to the AGP technology. After conversion into new technology, the plant would only require such inspections, maintenance after every 32,000 hours. It would also increase generation capacity and operational efficiency of the plant. “The AGP technology will also help to save time, money, labour etc besides adding electricity to the national grid uninterruptedly,” the official added.
He said the parts and other material purchased and required for the plant’s upgradation to AGP was mobilised to the project site. The CPGCL’s administration has also sought the plant’s shutdown for a period of about 20 days. And this has almost been approved by the quarters concerned. Hopefully the CPGCL (Gencos-II) administration would be informed formally by end of this week.
The official said the work on this would start within next two weeks or so, as all preparatory arrangements have been completed at site while the project would complete within a period of 60 days—30 days for each gas turbine.
Published in Dawn, March 11th, 2018