Analysis on Cause of Full Opening of Compressor Surge Valve and its Solution
Zhang Xide,Abudurehemu.Tuohuti,Gu Xingchun(PetroChina Tarim Petrochemical Company,Korla,Xinjiang, 841000,China)
Surge vent valve of multi-shaft air compressor opened suddenly three times within one day and air entering the secondary reformer was cut off,which resulted in fertilizer unit shutdown. Investigated and analyzed are causes of the accidents and found are relative influence factors. The results show that different causes resulted in such accidents. In one of the accidents,outlet valve and bypass line valve of the air compressor were in fully closed position, outlet pressure of one section rose rapidly up to more than 1.5MPa as pressure of the compressor was increased,which led to sudden full opening of its surge vent valve. Immediately following that,RPM (Revolutions per Minute)of the compressor steam turbine rose rapidly up to electronic tripping speed and trip happened. In other two accidents,steam extraction pipe was not fully heated,condensate in the pipe was carried into medium pressure steam pipe network when the turbine was running for steam extraction,and steam temperature in the pipe network greatly dropped and RPMof its steam turbine dropped down to less than 5743rpm,which led to sudden full opening of its surge vent valve. Corresponding measures have been taken according to the above- mentioned accident causes and good effect has been obtained and similar accidents can be avoided effectively.