9E Turning Gear Failure.doc

9E gas turbine turning failure analysis and processingThe Dongguan the Shennengyuan ZhangYang Electricity Co., Ltd. Li WeihuaAbstract: This article describes a few cases 9E gas turbine turning failure phenomenon, analysis and reasons given for may cause failure of turning, and given the failure of prevention and handling approaches. Keywords: 9E gas turbine, to deal with turning failure The gas turbine combined cycle generating unit has many fine characteristics, characteristic of the starting fast is one of the most important performance of the daily start and stop cycling unit. 9E gas turbine cooler and operation before the firing process, which we call turning. Turning failure, the unit from the normal stop cannot be assured, the normal overhaul faults elimination it is difficult to carry out. Failure of gas turbine turning Reason Analysis, and using appropriate methods to solve handling, it is very important. A) Definition of turning failure following a fault phenomenon, called turning failure.(1) Combustion engine during deceleration, when the speed reaches the turning speed, turning into losing gas turbine speed down to zero speed;(2) In the case of gas turbine in the process of low disk without instruction issued stop turning, the gas turbine speed down to zero speed;(3) Gas turbines stop turning to zero speed, in the case of start command is issued turning gas turbine remains zero speedB) The various causes of the failure of turning the main reason for turning failure can be divided into two categories:First class: due to the friction between the gas turbine rotor and stator the polishing the torque greater than the turning torque, making the turning gear stop in the middle or from zero turning failed. Such failure is caused by the following conditions.(1) Compressor / turbine rotor blade tip and the cylinder wall scuffing, scraping cylinder phenomenon;(2) A compressor / turbine top of the stator blades and the rotor hub outer wall exists abrasion;(3) The turbine moving blade contact Mount Sassafras exists between the roots and the top of the nozzle seal teeth;(4) gas turbine rotor journal and bearing between Mount Sassafras resistance increases, which may be due to damage to the bearing, bearing concentricity deviation from the design value, the rotor journal the concentricity deviation from the design value, bearing oil supply shortage orlow lube oil temperature and other causes;(5) jacking oil system is put from the top of the generator journal height is lower than the standard value, making the generator journal and bearing between Mount Sassafras resistance increases. Second category: power end starter motor (88CR) of low speed Turning gear (88TG) or failure of the hydraulic torque converter (HM1), makes the turning torque is lower than the design value, the turning cannot be normal.C) Turning failure cases1) 2004-07 early 3 # gas turbine load rejection test run was made after 30 minutes, the trip occurred for other reasons in the base-load state, low disk into losing speed dropped to 3.3% SPD, straight down to zero speed. The next day after inspection and manual / hydraulic disc car a few laps later, successfully put into turning. Analysts believe that the main reason for the failure of two, the first gas turbine is running in the basic load state shorter time, expansion of the rotor and the stator imbalance, the expansion of the rotor is greater than the stator; second is when the door opening between the turbine significantly faster cylinder cooling contraction; 2:00 caused friction between the rotor blades and stator cylinder wall, and the moment of resistance is greater than the turning torque.2) 2004-07 early # 3 gas turbine 40MW load hours after normal shutdown when the speed dropped to 3.3% SPD, low disk into losing speed straight down to zero speed. Reach zero speed for about 20 minutes, reverted to the the 88 CR start the motor, the gas turbine perform automatically from the cast plate car program, re-turning normal input. The reasons of the failures and examples are basically similar.3) 04-12-14, at 05:40,3 # in the morning gas turbine rinsed with water after the first water rinse, stop turning to do maintenance work, after 70 minutes, from zero cast and turning failed. turning manual / hydraulic turning 180 and throw the is not successful; disk and then turn 450 , the success of the cast and turning. The failure appears, we feel more accidents, because before this # 3 gas turbine experienced a dozen times successfully stop turning / zero from the cast plate car. The cause of the failure of the plate of the car to be investigation.4) 2005-01-02 night, the end of the minor repair work, # 3 gas turbine stops turning after 55 hours, from zero cast and turning failed. To the early morning of 2005-01-03, manual / hydraulic turning 450 , and successfully put into turning. The cause of the failure of the plate of the car to be investigation.5,1 # gas turbine after the shutdown normal input and low disc, then turn off after no more than one hours, the operating personnel in the inspection found in the turbine room exception scraping grinding sound, so open the door to enter the check after about 10 minutes, burningthe rotor has stopped rotating. After 13 hours by manual / hydraulic turning 450 , after zero-turning invest successfully. Analysts believe that the main reason of the failure is due to the gas turbine cylinder and rotor uneven cooling and contraction after the shutdown, the compressor / turbine rotor blade tip and the cylinder wall scuffing, scraping cylinder phenomenon, Mount polishing the moment of resistance is greater than the torque of the turning the last disc car down.turning failure examples through the example of the five turning failure inductive analysis, you can know the compressor / turbine rotor blade tip and the cylinder wall scuffing, scraping cylinder phenomena turning failure downward deflection of the natural, generally occurs after flameout of the shutdown process of deceleration and turning; experience from previous open cylinder check under Bangang wall scuffing probability, because the rotor heat up Wen Hougang decreased increases, the rotor blade easily come into contact with the inner wall of the next Bangang. Stop turning from zero turning failed, the reasons are more complex, involving many factors; start the motor power end (88CR), the torque converter (HM1), gas turbine rotor, stator, bearing and journal bearing, generator the jacking height of the oil pressure / temperature, any link failure will cause the turning failure. gas turbine start-ended input tray car unit rotor torque can not overcome the static friction torque, is the main reason for the failure of the zero-plate cars. The following is a list of the # 1, # 3 machine turning parameter table.# 1, # 3 machine turning parameter tableUNIT # Idling time LowdiskspeedHighdisk speedTMGV Opening Zero-turningperformance1# GT12 min 15 sec 4.0%SPD 24.1%SPD Higher value：63 Lower value：43 Anormalzerofromturning3# GT 12 min 18sec3.7%SPD 22.1%SPD Higher value：68Lower value：43 Not normallyzerosinceturning.Aftera certainpoint of viewofthe manual/hydraulicdisccar,to get ready forturning.Throughthistable informationanalysis,draw the following conclusions:1,1#3# gas turbine idling timebasicallyequal to2 sets ofgas turbineintherangeofidlingthe dragtorqueis basically the same;2, ifthetwosetsof gas turbineof the torque converterperformance intact,and# 3ofthe dragofthegas turbinerotortorqueisgreater than# 1inthelow / highdisc state,agas turbine;Inthelow/highdiskstate,ifthemoment of resistanceand1 #3#gas turbinerotorsufferedbasically the same,you canthat3#machinetorque converterinsufficient output;4,3#Barringgas turbinefrom zero, TMGVangleof68 ,# 1the machine5,butstill notsmoothfrom thedisk,theDescription3#machinerotorstatic frictionSassafrasthan1 #bigmore;5, in thezerospeed condition,combustion engine3 #manual /hydraulic disccar,allowsthepad surfacetocreateafilm,to improvetheunit eachbushlubricating propertiessuch thattherotor journalstaticfrictionforce reductionin thecrankingtorquethe sa