The Method Of The S109FA Unit's Operation About Deeply Unloading In The Abnormal Working Conditions－Studying The Actual Production Application In The Deeply Unloading Technology

The S109FA Gas-Steam Combined Cycle Unit has the advantages of high thermal efficiency, environmental protection, quick startup and shutdown, etc. It is generally used as a peak-load adjustment units, playing the key role in the task of peak-load adjustment. This paper expatiates on the function of deeply unloading of the S109FA under abnormal working conditions. Combined with the actual application at the Guangzhou Zhujiang LNG Power Generation Co., Ltd. (hereinafter referred to as "Zhujiang LNG Power Plant"), the deeply unloading technique with auto-stop scheme and sliding parameters stop scheme are studied. We summarize the deeply unloading operation principles and methods for The S109FA Unit, it includes:(1) On-line elimination by deeply unloading to avoid unexpected shutdown; (2) The operation principles of main for auxiliary system equipment when running under abnormal working conditions; (3) The unit can not maintain the load between 40MW and 115MW in the process of auto-stop deeply unloading. It got some application and attention including (1) using the deeply unloading properly, the defects of the S109FA Unit and its auxiliary systems can be eliminated on-line, avoiding unexpected extra downtime to eliminate defects. (2) this technology can reduce the waiting time to stop the turning gear, to achieve 62 hours ahead startup and maintenance of the main equipment.The life-time of the units is also investigated deeply, the conclusions are:(1) When using the sliding parameters shut-down method, we must prevent the increasement of the turbine stress which is caused by rapid decline of the main steam temperature; (2) The sliding parameters shut-down technique can slip the temperature of 1st stage bowl from 560℃to 370℃, reducing 62 hours waiting time for stopping the turning gears; (3) Reduce the influence of deeply unloading on the unit's life-time as much as possible.This research will serve as the site operation guidance and anti-accident measures for Zhujiang LNG Power Plant. The deeply unloading technique can not only bring considerable economic benefits for the enterprise, but also enhance the security credit of Zhujiang LNG Power Plant in the South China Power Grid Co., Ltd..