Saic - Siemens steam turbine common problems and Suggestions

Saic - Siemens steam turbine common problems and measures 2019 - 07 - 29 ( Zhejiang electricity institute) 1 Siemens steam turbine design, prevent the big shaft, holding in death of the seal clearance is small, the high load after downtime, no. 1 and 2 watts because the shaft seal steam temperature mismatch, lead to turning phenomenon occurs when the rotor, holding in death. Suggested measures: operation of electric heater of the shaft sealing device satisfies the requirement of shaft gland steam temperature; Strengthen the rotor eccentricity, 1 watt and turning speed vibration monitoring, increment, 1 watt vibration found eccentric and turning speed falls, should carry on the adjustment of the shaft sealing, destroy the vacuum when necessary and stop of the shaft sealing; Occurs after the rotor, holding in death of the boring cylinder processing, for the cylinder temperature drop after turning. More than 2, medium pressure steam door bolt fracture Siemens medium voltage main steam turbine door to tone and medium pressure bolt fracture, some of them are into bulk fracture, seriously affect the safe operation of the unit. Recommended measures: shortened when fastening bolt elongation; To improve bolt heating process; Change the material. 3, medium voltage tone diffusion tube crack medium pressure valve and the intermediate pressure cylinder with flange connection, medium voltage tone seat equipped with steam diffusion tube, after the intubation is located inside of flange connection, appears on many units diffusion tube at the bottom of the longitudinal crack phenomenon. At the bottom of the suggested measures: cancel the hydrophobic structure; Replace the crack intubation; Spread outside the bottom of the corresponding cylinder parts with monitoring station, strengthen the monitoring of intermediate pressure cylinder exhaust temperature. 4, the main door of the main steam valve screen broken Siemens unit mesh by corrugated steel strip coil assembly, on the outside of mesh frame for permanent filter, filter corrugated steel belt worn off, was rushed to the situation of high pressure cylinder. Recommended measures: to improve the structure of the main valve strainer; Improved filter processing and assembly process; To filter of 320 hz frequency vibration waveform, prevent the crushing of the screen when the high frequency vibration waveform caused by jumping. 5, steam unit gate valve disc sealing surface crack more steam gate valve disc of the sealing surface with a layer of hard alloy welded layer, the crack of hard alloy layer peeling phenomenon, even to judge from the macro crack has the characteristics of thermal fatigue crack. Suggested measures: repair the sealing surface, welding material choice and welding process on the improvement. 6, the wear of the high pressure rotor unit saic Siemens high voltage and medium voltage rotor bearing section of the parent metal welding, hardness is low, under the hard composition repeated friction, easy to cause the rotor wear surfacing layer. ( Note: this figure is only for your use) Recommended measures: unit overhaul key check the no. 1 and no. 2, prevent oil gear scale and large shaft wear; Equipped with instrument with air pipe purging piping; Strengthen the no. 1 and no. 2 bearing vibration monitoring. 7, damage to the hydraulic disc clutch, suggested measures: considering hydraulic turning when installation and large shaft connection Yang degrees; Cold is input, manual turning can confirm the steam turbine rotor rotation normally. Eight, six levels of two extraction steam pipe steam temperature deviation in high load big suggested measures: six levels of two extraction steam pipe drain pipe road separate arrangement, open when in low degree of superheat steam trap; Six levels of extraction steam in the condenser is equipped with two heat insulation board.