Oman Salalah II Project Achieved Success on APS Start-up and Shutdown with One Button


  With the guidance of the EPC project and the joint effort of the project commissioning team and other parties, Oman Salalah Phase II GT Combined Cycle Power Generation Project achieved success on APS on November 23rd, 2017 and passed the owner’s acceptance check, which means that the project can be controlled automatically from GT blowing to ST synchronization with specified load, and it created conditions to accomplishing the following works to the project.
  The APS means the automatic control from GT starting, to the automatic load rising after combined cycle unit synchronization, including GT automatic ignition and synchronization, boiler temperature and pressure rising, ST ATC running, automatic synchronization with load, and the automatic control from normal operation to safe shutdown. It is not only a comprehensive test to the plant control system and the process system but also the biggest test to the project before reliability operation.
  Oman Salalah Phase II has the three-pressure HRSG, its steam turbine is the three-pressure reheat, axial exhaust and direct air cooling type, and the gas turbine is the 6FA double fuel turbine. At the beginning of the project construction, there was no available APS logic and no regulation of temperature and pressure rising under combined cycle and ST running parameters, which brought great challenge to APS commissioning work.
  However, our project team did not lose heart. With the guidance of the leaders of head office and the EPC project, the team set APS group to take the responsibility of the programme design and commissioning optimization works.
  The group made a whole design and optimization plan according to the onsite reality, including the technological requirement, control system breakpoint, system architecture, APS starting and shutting methods, connection design between GT, ST and boiler, functional group using and quitting. It worked on starting curve optimization, steam combining optimization, water-steam cycle middle link optimization, vacuum speed up, high, middle and low bypass interlock optimization, ST valve and pipes parameters optimization, improved the unit starting and shutting speed and response smoothness a lot, achieved success on APS and enriched the APS production of the company.