Turbine helpful intro

Steam Turbine Training

Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

2

Topics  General

Information about steam turbine

1) Definition of steam turbine 2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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Steam Turbine Definition



A steam turbine is a device that extracts thermal energy

from pressurized steam and uses it to do mechanical work on a rotating output shaft.

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Topics  General 1)

Information about steam turbine

Definition of steam turbine

2) History of steam turbine 3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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History of steam turbine

The first device that may be classified as a reaction steam turbine was little more than a toy, the classic Aeolipile.

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History of steam turbine  Parson  de

steam turbine in 1884, 7.5 kW (10 hp) of electricity.

Laval turbine

 Aurel

Stodola, a Slovak physicist and engineer and professor at Swiss Polytechnical The Steam Turbine and its perspective as a Heat Energy Machine.

 Brown-Curtis

turbine developed in the 1900s

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3) Turbine type 4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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Turbine Types  According

to Steam Supply & exhaust condition

1. Condensing turbine 2. Back pressure turbine 3. Reheat turbine 4. Extracting type turbine

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Turbine Types  According

to Casing or shaft arrangement

1. Single casing turbine 2. Tandem compound turbine 3. Cross compound turbine 

Two-flow rotors turbine



According the way extracting energy from steam

1. Reaction turbine 2. Impulse turbine

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Impulse & reaction turbine  To

maximize turbine efficiency the steam is expanded, doing work, in a number of stages. These stages are characterized by how the energy is extracted from them and are known as either impulse or reaction turbines. Most steam turbines use a mixture of the reaction and impulse designs: each stage behaves as either one or the other, but the overall turbine uses both. Typically, higher pressure sections are impulse type and lower pressure stages are reaction type.

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Impulse turbines 

An impulse turbine has fixed nozzles that orient the steam flow into high speed jets. These jets contain significant kinetic energy, which is convert into shaft rotation by the bucket like shaped rotor blades, as the steam jet changes direction.

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Impulse turbines 

In the reaction turbine, the rotor blades themselves are arranged to form convergent nozzle's. This type of turbine makes use of the reaction force produced as the steam accelerates through the nozzles formed by the rotor. Steam is directed onto the rotor by the fixed vanes of the Stator. It leaves the stator as a jet that fills the entire circumference of the Rotor

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4) Principle of operation and design 5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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Principle of operation and design  An

ideal steam turbine is considered to be an isentropic process, or constant entropy process, in which the entropy of the steam entering the turbine is equal to the entropy of the steam leaving the turbine.

 No

steam turbine is truly isentropic, however, with typical isentropic efficiencies ranging from 20–90% based on the application of the turbine.



The interior of a turbine comprises several sets of blades, One set of stationary blades is connected to the casing and one set of rotating blades is connected to the shaft. The sets intermesh with certain minimum clearances, with the size and configuration of sets varying to efficiently exploit the expansion of steam at each stage. The world leader in gases for industry, health and the environment

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5) Operation & Maintenance 6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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Operation & Maintenance  Steam

Turbine warm up

1) the main steam stop valves (after the boiler) have a bypass line to allow superheated steam to slowly bypass the valve and proceed to heat up the lines in the system along with the steam turbine. 2)

Also, a turning gear is engaged when there is no steam to the turbine to slowly rotate the turbine to ensure even heating to prevent uneven expansion.

3) After first rotating the turbine by the turning gear, allowing time for the rotor to assume a straight plane (no bowing), then the turning gear is disengaged and steam is admitted to the turbine, first to the astern blades then to the ahead blades slowly rotating the turbine at 10–15 RPM (0.17–0.25 Hz) to slowly warm the turbine.

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Operation & Maintenance  Speed

regulation

The control of a turbine with a governor is essential, as turbines need to be run up slowly, to prevent damage while some applications (such as the generation of alternating current electricity) require precise speed control. Uncontrolled acceleration of the turbine rotor can lead to an overspeed trip, which causes the nozzle valves that control the flow of steam to the turbine to close. If this fails then the turbine may continue accelerating until it breaks apart, often spectacularly. Turbines are expensive to make, requiring precision manufacture and special quality materials.

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Operation & Maintenance  Steam

turbine maintenance

1) Vibration (imbalance of rotor) 2) Rapid impingement / erosion of the blade (water get in) 3) Destruction of thrust bearing (water get in)



Maintain steam quality (Dry & Superheated steam)

1) PH (J10 water, 9.6 to 10.2) 2) Degas cation Conductivity 0.2 to 0.3 ps/cm 3) Pressure (J10, ST2, 10.2 bar, ST1, 42 bar) 4) Temperature (J10, ST2, saturated T 187°C, ST T 217°C, ST1 T 373°C)

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6) Thermodynamics of steam turbines 

HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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Thermodynamic of steam turbines  Rankine

cycle

The Rankine cycle is a cycle that converts heat into work The world leader in gases for industry, health and the environment

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Thermodynamic of steam turbines  Process

1-2: pressure build up

 Process

2-3: temperature build up

 Process

3-4: translate pressure & temperature into kinetics

 Process

4-1: condense stage

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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HTC turbine type



HTC mainly supplies the reaction turbine with following 10 basic models:

NK, NG, HG, ENK, ENG, HNK, HNG, EHNK, EHNG and WK. The meanings of each letter are defined as follow: 1.

N: usual inlet steam parameters 10.0Mpa (a), 510°C, max

2.

H: High inlet steam parameters 14.0Mpa(a), 510°C, max

3.

K: Condensing steam turbine

4.

G: Back-pressure steam turbine

5.

E: Extraction steam turbine

6.

WK: Condensing steam turbine with double split flow, Max Inlet steam parameters: 1.6Mpa(a), 420°C

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HTC turbine type  ST5001 Type: NG32/25 NG: Backpressure steam turbine with usual inlet steam parameters 32: the inner diameter of steam inlet section is 320 mm 25: the diameter of last stage of the rotor is 250 mm No extension section

 ST5002  Type:

NK50/56

NK: Condensing steam turbine with usual steam parameters 50: the inner diameter of steam inlet section is 500 mm 56: the diameter of last stage of the rotor is 560 mm No extension section The world leader in gases for industry, health and the environment

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1) Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Turbine casing

9) Main oil pump

4)

Seal ring of L-shaped cross section

5)

Eccentric guide stem

6)

Guide blade carrier The world leader in gases for industry, health and the environment

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HTC turbine – Condensing system

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HTC turbine – Condensing system  Main

Function of Condenser

1) Condense the exhaust steam into condensate & carry off the heat when steam was condensed 2) Build & maintain the vacuum at turbine exhaust port so that the steam expander pressure is reduced as low as possible 3) It increase the usable enthalpy drop of steam 4) Condensate may be circularly used

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HTC turbine – Condensing system  The

main failure of Condenser

Vacuum is keeping decreasing for some reasons

 How

to detect the vacuum failure

1. Through vacuum gauge 2. Temperature condition of exhaust casing 3. Inlet opening of air ejector 4. Starting of the standby air ejector

 Potential

cause of the vacuum failure

1. No cooling water supply 2. Not enough cooling waiter supply 3. Water level high 4. Cooling surface dirt of condenser 5. Vacuum system leakage is excess 6. Air ejector working abnormal The world leader in gases for industry, health and the environment

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC 1)

Turbine Introduction

Condensing system

7) Rotor

2) Air ejector

8) Control Valve

3)

Control system

9) Main oil pump

4)

Turbine casing

5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7)

Guide blade carrier

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HTC turbine – Air ejector  The

main function of air ejector

To extract air from steam side of condenser continuously so that condenser maintain a vacuum and transmits heat

 Main

failure of air ejector

1. Difference between water outlet temperature & the vent steam temperature is increased 2. Water/steam accumulation

in vent outlet

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HTC turbine – Air ejector  Potential

cause of air ejector failure

1.

Leakage on the air suction piping or valve stem

2.

Steam pressure is different with the design value

3.

Humidity of steam is too high

4.

Damage of the strainer cause nozzle blocked

5.

Nozzle & expansion piping is rusty

6.

Nozzle location is wrong

7.

Condensing pressure is high

8.

Ejector is running at over-load condition

9.

Drain piping of inner-condenser and after condenser is chocked

10. Leakage with the tube sheet 11. The cooling of mix air is not enough 12. Cooling water quantity is not enough The world leader in gases for industry, health and the environment

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3) Control system 4)

Turbine casing

5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7)

Guide blade carrier

9) Main oil pump

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HTC turbine – Control system  Control

system = Governing system + Auxiliary system + Monitoring system + protection system 1. Governing system=speed control 505 2. Auxiliary system= steam control, pump control, ect 3. Monitoring system=vibration & position monitoring 4. Protection system= shutdown signal control

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Control system

9) Main oil pump

4) Turbine casing 5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7)

Guide blade carrier

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HTC turbine – turbine casing 

The casing is a container for the through-flow section of the turbine. The casing consists of the front casing and rear casing (exhaust casing) which have vertical joint surface. They are also divided along the horizontal plane into top and bottom halves. The vertical and horizontal split flanges are connected with bolts.



The front casing is a steel casting, while the exhaust casing is iron casting or welds.

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Control system

9) Main oil pump

4)

Turbine casing

5) Seal ring of L-shaped cross section 6)

Eccentric guide stem

7)

Guide blade carrier

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HTC turbine – Seal ring of L-shaped cross section 

In the reaction turbine (except for the model WK), an seal ring of L-shaped cross section is used as the connection between the outer casing and inner casing, nozzle box or steam chamber. The steam from the governing valve enters into the corresponding steam dome of the nozzle box via the angle ring. There are 2 structures of angle ring.

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HTC turbine – Seal ring of L-shaped cross section 

In the reaction turbine (except for the model WK), an seal ring of L-shaped cross section is used as the connection between the outer casing and inner casing, nozzle box or steam chamber. The steam from the governing valve enters into the corresponding steam dome of the nozzle box via the angle ring. There are 2 structures of angle ring.

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Control system

9) Main oil pump

4)

Turbine casing

5)

Seal ring of L-shaped cross section

6) Eccentric guide stem 7)

Guide blade carrier

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HTC turbine – Eccentric guide stem 

The lateral or axial centres of the inner casing, the steam chamber, the guide blade carrier and the labyrinth seal is adjusted with the eccentric guide stem when mounting them into the outer casing. In the backpressure turbine, the alignment between the casing and the rear pedestal is adjusted with the eccentric guide stem.

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Control system

9) Main oil pump

4)

Turbine casing

5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7) Guide blade carrier

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HTC turbine – Guide blade carrier 

The guide blade carrier is one of the essential component in turbine through-flow section and accommodates several stages of fixed blades. There is one or several guide blade carriers of pressure stages with different size in a turbine according to the different parameters and characteristics. The structure of the guide blade carrier is showed below.



The guide blade carrier is horizontally split into top and bottom halves jointed with bolts and positioned with the pins

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Control system

9) Main oil pump

4)

Turbine casing

5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7)

Guide blade carrier

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HTC turbine - Rotor

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HTC turbine - Rotor



The rotor is a single forging together with the control stage disc and thrust collar, on which the emergency governor, the moving blades, the sealing strips, the ratchet wheel for turning gear and the coupling are mounted.



3 kinds of blades, control

stage, the pressure stage (or called as drum stage) and the low-pressure stage. The front two are the milled straight blades with integral shroud, while the moving blade of the low-pressure stage is twisted blade made with finish forging or machined electrochemically.



The low-pressure stages of the condensing turbine work in the wet-steam region, so the steam flowing out of the guide blade contains the water droplets. The axial

distance between the guide and moving blades in the low-pressure stage is kept large to facilitate the acceleration, separation and atomization of any water droplets. This will reduce the impact and corrosion of the droplets on the leading edges of the blades. Taken the effects of the speed, humidity and condenser pressure into account, the leading edges of the last moving blades are hardened if necessary.

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HTC turbine - Rotor  dynamic

balancing and over speed testing of the

rotor 1.

The rotor dynamic balancing is done on the high speed dynamic balancing machine at the turbine operating speed to correct the dynamic unbalance quantity within the limit defined in the relative standard through changing the mass distribution of the balancing weights or screws on the balancing planes. The dynamic unbalance quantity on the rotor is caused by non-uniform mass distribution of the rotor material, machining error and assembling deviation.

2.

The rotor over speed test is one of the factory inspection items, it should be done on special device under defined operating condition and environment,

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control

3)

Control system

9) Main oil pump

4)

Turbine casing

5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7)

Guide blade carrier

Valve

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HTC turbine – Control valve

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HTC turbine – Control valve  Function

of Control valve

The control valve functions for regulating the steam flow based on the command from the control unit to make the controlled parameters (output or speed , inlet steam pressure, back pressure and etc.) of the turbine meet the operation requirement.

 Structure

of Control valve

The control valve consists of three main sections, the governing

valve -- valve spindle, valve beam, valve cone and valve seat, the operating mechanism-- support and lever, the oil relay

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HTC turbine – Control valve  Governing

Valve

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HTC turbine – Control valve  Oil

relay

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Topics  General

Information about steam turbine

1)

Definition of steam turbine

2)

History of steam turbine

3)

Turbine type

4)

Principle of operation and design

5)

Operation & Maintenance

6)

Thermodynamics of steam turbines



HTC turbine type

 HTC

Turbine Introduction

1)

Condensing system

7) Rotor

2)

Air ejector

8) Control Valve

3)

Control system

9) Main

4)

Turbine casing

5)

Seal ring of L-shaped cross section

6)

Eccentric guide stem

7)

Guide blade carrier

oil pump

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HTC turbine – Main oil pump

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HTC turbine – Main oil pump  Function

of main oil pump

1. The main oil pump provides the turbine-set with governing oil and lubricating oil. It is a single-stage, horizontal centrifugal pump and is directly driven by the turbine rotor.

 Structure

of main oil pump

1. single-cast design 2. aluminium alloy impellor

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Steam Turbine Training

END Q&A

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