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1. STEAM TURBINE STRUCTURE , SYSTEMS, OPERATION AND MAINTENANCE

2. TURBINE STRUCTURE Turbine rotating part Cylinder Slide pin system Bearing &bushing

3. Rotor structure of turbine Rotor definition: the combination of all rotating components in a turbine is called rotor

4. 1-shaft ； 2-impeller ； 3-blade ； 4-axial thrust ring; 5-bearing journal; 6-shoulder of HP and LP gland seal;7-beading of interstage or diaphragm gland seal; 8-overspeed cutoff device; 9-helical worm; 10-impeller of oil pump; 11-blade balance hole; 12-balance ring; 13-shaft coupling

5. Turbine body 、 Cylinder Turbine body are the fixed parts include the nozzle chamber cylinder, diaphragm, static blades, gland seal; The composition of control parts are conditioning systems, protection device, oil systems and so on. Definition of cylinder: The steam turbine cylinder is the shell of the steam turbine

6. The role of the cylinder is separated the turbine flow passage (nozzle, diaphragm, rotor, etc.) from the atmosphere, to ensure process of steam doing work in the turbine. In addition, it also support some of the stationary part of the turbine (diaphragm, the nozzle chamber, steam envelope, etc.), to bear their weight, but also to withstand the thermal stress produced by temperature uneven distribution along the cylinder axial and radial.

7. Steam turbine slide pin system In order to reach the long-term steady unit operation, the thermal expansion of cylinder shall satisfy the following requirements When temperature changes, the center of cylinder and rotor must always be consistent, can not cause vibration and the friction of static and dynamic components; Temperature changes will not cause the deformation and crack of the cylinder, bearing block and other related parts; The axial clearance of turbine rotor and static part meets the requirements, ensuring the operation safety and economy.

8. To meet the above requirements, cylinder is equipped with a sliding pin system:

9. Horizontal pin : usually mounted on the transverse center line of the Exhaust steam casing of the low-pressure cylinder, or mounted at the rear of the Exhaust steam casing. Both sides are equipped with one. It guides cylinder to expand laterally and restricts the cylinder to move in an axial (longitudinal) direction

10. The longitudinal pin : it is usually installed on the support surface of the low-pressure cylinder exhaust chamber, bottom of front bearing box, joint surface between bottom of middle bearing and others and turbine base plate surface

11. BEARING AND BUSHING Function: to bear the full weight of the rotor and the additional force of the rotor vibration caused by part of the inlet steam, and to determine the radial position of the rotor, keep its center and the cylinder center are consistent.

12. Bushing grinding: in order to meet the requirements of tile contact surface between the rotating shaft and the bushing, make sufficient lubricating oil film between the rotating shaft and the bushing, reduce operation friction, in the process of installation or maintenance in order to achieve this purpose, to carry out corresponding artificial technology treatment.

13. Function and structure of thrust bearing Function of thrust bearing: bear the axial thrust that the steam acting on the rotor and to determine the axial position of the rotor, keep a certain clearance between the rotor and the stationary part.

14. STEAM TURBINE SYSTEM Turbine oil supply system Turning gear system Main steam system Control and protection system Shaft sealing system Extraction system Vacuum system Feed pump and condensing system

15. TURBINE OIL SUPPLY SYSTEM Function of oil system Function of oil supply system Lubrication Cooling For regulating system For security system

16. MAIN PARTS OF OIL SYSTEM Main oil pump Auxiliary oil pump (HP ) Emergency DC and AC oil pump Jacking oil pump Coolers ,filter ,ejectors and foam extraction fans

17. TURNING GEAR SYSTEM Definition : The device that drives rotor before units’ startup or after shutdown called turning gear Function :- At the beginning of turbine warming up ， the steam heat flow is up and the upper part of rotor is heated faster than the lower part, resulting in rotor bending upward. In order to ensure friction-free between the static part and movement part, low-speed rotation driven by turning gear first to ensure the rotor is heated evenly. The cylinder and rotor are from hot to cold after shutdown. This is certain to affect the clearance between static part and movement part, and increase the bending of rotor, so it needs to start turning gear after unit shutdown, in order to ensure that the rotor uniform cooling and the unit startup.

18. Turning gear starting condition all main steam valves close. Lube oil pressure normal. Jacking oil pressure normal Electronic equipment normal. Rotor speed zero.

19. MAIN STEAM SYSTEM Definition: From super heater outlet steam goes through main steam pipe, main steam valve, adjustment steam valve and steam chamber of turbine, and goes into high pressure casing equipment and pipes, called as main steam system. Electrical isolation valve function : is in front of main steam valve, in charge of shutting off the steam inlet when turbine shut down, usually not connected with protection system. Auto main steam valve function : When emergency shut down of turbine is needed, the safety protection device will work, and turn off the main steam valve immediately, cut off the steam resource, ensure the equipment safe.

20. CONTROL AND PROTECTION SYSTEM The principle of turbine's regulation: The main steam turbine generator torque and counter torque imbalance speed changes into the pulse signal to control the steam turbine into, so as to ensure that in the new condition, the main steam turbine generator torque and counter torque rebalance, and maintain a substantially constant rotational speed of the turbine generator.

21. Electrohydraulic system （ 1 ） Speed adjustment circuit （ 2 ）Power conditioning circuit （ 3 ）Power - frequency adjustment circuit Using power, frequency this two adjustment signal s , and three basic adjustment circuit:

22. DEH is composed of electronic control part and hydraulic control security part. The electronic control is mainly composed by distributed control system DCS and DEH special module, it completes signal acquisition, comprehensive calculation, logic processing, man-machine interface and so on. Hydraulic control security part is mainly composed by electro-hydraulic converter, electromagnetic valve, servomotor, steam distribution device and so on, it converts electrical control signal into hydraulic mechanical control signal, and eventually control the opening of the steam inlet valve.

23. VACUUM AND SHAFT SEALING SYSTEM VACUUM JET SYSTEM : In the process of starting or stopping, the vacuum in the condenser is formed by the extraction of air from the main and auxiliary air suction units; In normal operation, the vacuum in the condenser is formed due to the sudden condensation of the exhaust gas of the turbine in the condenser and the decrease of the specific volume of the water (the effect of the pumping unit is to draw out non condensable gas)

24. Principle of water jet steam ejector: the working water from water jet pump with certain pressure enter into the nozzle through the water chamber. The nozzle will transfer the pressure energy of pressure water into speed energy, high speed waterflow eject from nozzle, make the air suction chamber produces high vacuum, draw out of steam and gas mixture in the condenser to go into the diffusion tube, then waterflow is getting slower, pressure gradually increases, at last it is discharged out of diffusion tube with pressure slightly higher than the atmospheric pressure. At the inlet of air suction chamber equipped with check valve, it can prevent water sucked into the condensing chamber when air extractor failure.

25. GLAND SEALING SYSTEM

26. The function of gland Seal System is to prevent the air leak into the cylinder or steam escaping from the cylinder at the position that rotor pass through the cylinder, and recovery of the leakage steam of turbine gland seal, use its heat heating part of the condensate water, while it can extract the gas mixture out of the steam of the turbine shaft seal system to prevent steam leak into the turbine room or oil system. Gland seal system mainly consists of the surge tank, gland seal heater, gland seal heater fan (steam jet air ejector), pipeline, valves and other components

27. Function of gland sealing cooler: The gland sealing cooler is a heat exchanger, using the function of steam jet ejector (gland seal heater fan) to lead the steam leakage of gland seal heater at the end of turbine, and use the heat of leaked steam to heat the condensed water, reclaiming heat and work medium. Air and uncondensed gas will be discharged by the air ejector installed on top of air cooler. Generally using main condensate water as cooling medium.