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How does a steam turbine work?

Introduction – How does a steam turbine work?

To understand How Does a Steam Turbine Work, we must first understand some details about its operating fuel, steam.

Steam, like all fluids, has basically three basic forms of energy:

Inside the turbines there are many parts that we will discuss throughout the topics. But today we will highlight and discuss one of the most important ones, which are the blades.

Each blade of a steam turbine contains an aerodynamic profile that causes a pressure difference when steam passes through it.

So basically, the process is as follows:

1° The steam enters the turbine at a certain temperature and pressure;

2° The steam is directed to a part (expansion plate or diaphragm ) that directs the entire steam flow to the blades;

3° The blades are fixed to wheels, which in turn are connected to an axle or the turbine rotor;

Therefore, during the operation of a steam turbine, the steam will always be directed towards the blades, where at the top of the profile, that is, inside the blade, there is a higher pressure and outside, a lower steam pressure.

This pressure difference, aided by Newton’s action and reaction force , creates a type of lifting force, and it is this force that is responsible for making the rotor turn.

What is a Steam Turbine?

A steam turbines is a mechanical device that extracts thermal energy from pressurized steam and converts it into mechanical work.

This mechanical energy can then be used to drive electrical generators, pumps, or compressors. Steam turbines are widely regarded for their efficiency and adaptability, making them a cornerstone in power generation and industrial processes.

Steam turbines consist of a series of rotors and stators. Steam flows through these components, causing the rotor blades to spin and generate rotational energy.

Their versatility allows them to operate in various environments, from small-scale industrial applications to massive utility-scale power plants.

During the operation of a steam turbine, the steam expands, which means that it gains speed while its pressure and temperature decrease as the steam passes through the turbine wheels.

But going back a little further, before the steam passes through the turbine wheel blade, it is necessary to expand this steam to increase its speed.

Therefore, the pressure and temperature of the steam are lower in each stage (wheel + expander assembly) towards the turbine exhaust.

Thus, the lifting force of the steam alone is not effective and cannot make the rotor turn on its own.

"A steam turbine is a mechanical device that extracts thermal energy from pressurized steam and converts it into mechanical work."

How does steam expansion occur in steam turbines?

The expansion of steam in the turbine occurs through the pressurization of the steam, to achieve a gain in kinetic speed.

Inside steam turbines, the parts that do this are the diaphragms and the expander plates.

Why does the steam turbine have a stepped shape?

This staggered appearance of steam turbines, that is, successively larger wheels and blades along the turbine, has the function of accommodating all the expansion of the steam.

In any closed system, physical or chemical, matter is never created or eliminated, it is only possible to transform it from one form to another.

Therefore, the mass of steam entering the turbine must be the same as that leaving the turbine.

Furthermore, in any pressurized system such as a turbine, which uses steam as fuel, every time there is a drop in pressure in the process, there is an increase in volume, therefore the steam flow increases.

Another detail is that the smaller blades are subjected to higher temperatures and pressures, while the larger blades undergo greater stress and mechanical stress.

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How do these parts extract energy from the steam?

Looking at the profile of an expansion plate or diaphragm, we observe a reduction in the area through which the steam passes, i.e., a restriction in the flow of steam.

This causes a decrease in pressure but an increase in the kinetic speed of the steam. This effect is called Venturi .

Applications of Steam Turbines

Steam turbines is used in a variety of settings:

- Power Plants: Coal, natural gas, nuclear, and geothermal power stations.
- Oil and Gas Industry: Driving compressors in refineries and pipelines.
- Chemical and Pharmaceutical Plants: Supporting manufacturing processes.
- Desalination Plants: Powering systems that convert seawater into freshwater.

Principle of Operation Steam Turbines

The operation of a steam turbine is based on thermodynamic principles, particularly the Rankine cycle:

High-pressure steam enters the turbine through nozzles.
The steam expands and loses energy, causing the rotor blades to spin.
The rotational energy is transmitted to a shaft, which drives an external load, such as an electric generator.
Low-pressure steam exits the turbine, often utilized in heat recovery systems or condensed into water for reuse.

Types of steam turbines

Steam turbines are divided into two types:

Condensing steam turbines

Condensing steam turbines are those that make the most of the potential energy of steam.

Therefore, the steam that leaves the turbine can no longer be used to generate energy due to its content already being in a liquid state.

In these turbines, steam at a pressure lower than atmospheric pressure (vacuum) is directed to the condenser.

Backpressure steam turbine

In backpressure turbines , the steam leaving the turbine still has enough energy to power other industrial processes before returning as water to a boiler.

The exhaust steam from these turbines is mostly found in the superheated region.

This type of joint generation of electrical energy and thermal energy from a single fuel source is commonly called cogeneration.

In these turbines, the output steam has a pressure greater than atmospheric pressure.

Comparing Steam Turbine Solutions

Criteria	Condensing Turbine	Backpressure Turbine
Primary Use	Power generation	Industrial heat and power
Efficiency	Higher thermal efficiency	Optimized for cogeneration
Steam Usage	Fully exhausted	Partially used
Cost	Higher upfront cost	More economical

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DIGITAL STEAM TURBINE COURSE ADVANCED MODULE

See the topics in the tab below. Total course load 25h.

*Includes the Essential Module

SUBJECTS / CLASSES

ESSENTIAL – Module 1

Start Here
Features and Tools
Course Presentation
Introduction
Application
Rankine Cycle – Transforming Heat into Work
Thermal Cycle Equipment
Types of Steam Turbines
Condensing Turbine
Backpressure Turbine
Types of Extraction
Speed Diagram
Principles of Action and Reaction
Stage / Action Turbine (Impulse)
Stage / Reaction Turbine
Curtis Type Stage
Rateau Type Stage

ESSENTIAL – Module 2

Single and Multistage Turbines
Direction of Rotation
LOA-LA / HP-LP / AP-BP Concept
Components
Components – Steam Chamber
Components – Emergency Valve
Components – Partializing Valve
Components – Casings
Components – Injector / Expander
Components – Rotor
Components – Vanes
Components – Belt
Components – Fixed Vanes (Reverser)
Components – Diaphragm
Components – Diaphragm Holder
Components – Vane Holder
Components – Radial Bearing
Components – Axial Bearing
Components – Bearing Housing
Components – Vapor Sealing System
Components – Vapor Sealing – Carbon Ring
Components – Vapor Sealing – Labyrinth Ring
Components – Vapor Sealing – Sealing Blades
Components – Oil Sealing
Components – Mechanical Speed Regulator
Components – Electronic Speed Regulator
Components – Actuator
Components – Coupling
Components – Reducer
Components – Slow Rotation
Components – Lubrication System
What is TRIP?
Condensation System
Condensation System – Devices
Certificate
Final Considerations and Certificate

ADVANCED – Module 1 – Introduction and Fundamentals

Start Here
Course Presentation
Introduction
Historical Context
Application
Waste To Energy – Energy Recovery Plant “URE”
Module 1 Handout

ADVANCED – Module 2 – Basic Thermodynamics for Steam Turbines

Thermodynamic Characteristics
Steam Thermal Plant Cycles
Rankine Cycle – Transforming Heat into Work
Thermal Cycle Analysis – Condensation Turbine (Efficiency Comparison)
Thermal Cycle Equipment
Practical Rankine Cycle
TS Diagram
Mollier Diagram
Rankine Cycle Variations
Reheat Cycle
Regenerative Cycle
Combined Cycle
Reuse of Thermal Energy
What is Steam?
Quiz 1
Module 2 Handout

ADVANCED – Module 3 -Classification of Steam Turbines

Classification of Steam Turbines
Types of Steam Turbines
Condensing Turbine
Backpressure Turbine
Pressure Reduction Turbine
Types of Extraction
Operating Principle
Speed Diagram
Principles of Action and Reaction
What is a Stage?
Action (Impulse) Stage / Turbine
Reaction Stage / Turbine
Curtis Type Stage
Rateau Type Stage
Quiz 2
Single and Multistage Turbines
Radial and Axial Turbines
Direction of Rotation
LOA-LA / HP-LP / AP-BP Concept
Applicable Standards
Internal Losses
Turbine Efficiency
Saturation Curve
Quiz 3
Module 3 Handbook

ADVANCED – Module 4 – Components Part 1

Components
Components – Steam Chamber
Components – “Quick Closing” Emergency Valve
Components – “Quick Closing” Emergency Valve Part 2
Components – Partializing Valve
Components – Casings
Torquing Turbine Casings – Hydraulic Tensioner
Sealant for Junction Plane (Housings) and Flanges
Components – Hood Spray System
Components – Injector / Expander
Components – Rotor
Rotor Components – Balance Piston
Rotor Components – Control Wheel (Wheel Chamber)
Rotor Components – Rigid and Flexible
Rotor Components – Runout
Rotor Components – Magnetization
Quiz 4

ADVANCED – Module 5 – Components Part 2
Automatically released after 7 days from the date of purchase.

Rotor Components – Alignment
Rotor Components – Mechanical Alignment
Rotor Components – Piano String Alignment
Rotor Components – Laser Alignment
Rotor Components – Catenary Curve
Rotor Components – Critical Speed
Rotor Components – Vibration
Rotor Components – Balancing
Quiz 5
Balancing – High Speed Balance
Components – Vanes
Components: Vanes: 3D Printing
Components – Belt
Components – Fixed Vanes (Reverser)
Components – Diaphragm
Components – Diaphragm Holder
Components – Vane Holder
Module 5 Handbook

ADVANCED – Module 6 – Components Part 3

Automatically released after 7 days from the date of purchase.

Components – Radial Bearing
Bearing Components – Operating Principle
Radial Bearing Components – Cylindrical
Radial Bearing Components – Pressure Dam
Radial Bearing Components – Multilobular
Radial Bearing Components – Tilting Pad
Radial Bearing Components – Oil Lift
Bearing – General Concepts
Bearing Components – Materials
Bearing Components – Temperature Monitoring
Components – Tilting Pad Bearing – Temperature Monitoring
Radial Bearing Components – Alignment
Radial Bearing Components – Clearance
Radial Bearing Components – Clearance Complement
Components – Radial Bearing – Clearance Check
Axial Expansion
Components – Axial Bearing
Quiz 6

ADVANCED – Module 7 – Components Part 4
Automatically released after 7 days from the date of your purchase

Components – Bearing Housing
Components – Vapor Sealing System
Components – Vapor Sealing – Carbon Ring
Components – Vapor Sealing – Ring Maze
Components – Vapor Sealing – Sealing Blades
Components – Oil Sealing
Turbine Speed Control – Overview
Components – Mechanical Speed Governor
Mechanical-Hydraulic Speed Governor – Deep Dive
Components – Electronic Speed Governor
Components – Actuator
Components – Coupling
Quiz 7
Components – Reducer
Components – Slow Rotation
Components – Thermal / Acoustic Insulation
Components – Base and Foundation

ADVANCED – Module 8 – Systems: Condensation, Control, Safety and Others
Automatically released after 7 days from the date of purchase.

Condensation System – Overview
Condensation System – Devices
What is TRIP?
Types of TRIP – Turbine Disarming
TRIP Disarming Standards and Criteria
Synchronization

ADVANCED – Module 9 – Lubrication System
Automatically released after 7 days from the date of purchase.

Lubrication System – Overview
Lubrication System – Consumers
Lubrication System – Hydraulic Unit
Oil Catcher Ring Applied in Single-Stage Turbines
Oil Contamination Level – NAS Indicator
Limit Concentration of Water in Oil
Flushing in Lubrication System

ADVANCED – Module 10 – Operation, Inspection and Maintenance
Automatically released after 7 days from the date of purchase.

Turbine Start-up and Stop Curves
Turbine Start-up Procedures
Main Materials
NDT – Non-Destructive Testing
Routine Operation and Maintenance
Failure Analysis and Solutions
Performance Analysis and Diagnosis
Assembly Clearances
Questionnaire 8
Certificate
Instructions for issuing your Certificate
Final Considerations and Certificate

Module – Learning About Varnish

Handout 4

Concept, formation, detection, correction and prevention of varnish formation
Introduction to varnish
Types of Turbine Oils
What is varnish?
Varnish Formation
Why the increasing trend in varnish formation? Varnish Presence Limits and Correction
Patent Metal Adhesion Module

Inspection Guide and Technical Standards
Introduction
Patent Metal Application Methods
Patent Metal Application Standards
Details ISO 4386 Part 2 Destructive Testing
Design for ISO 4386 Part 2 Laboratory Testing
Manufacturing Test Specimens for ISO 4386 Part 2 Laboratory Testing
Execution of Destructive Tensile and Compression Testing

Failure Analysis Modules

Steam Turbine Blade – Shear
Failure Analysis of Unexpected Steam Turbine Trips
Remote Diagnostic Analysis – Excessive Vibration Problem Solution
Rotor and Stator Blade Erosion Analysis
Vane Failure – Change in Opening of Partializing Valves
PED Bearing Resonance LOA
Introduction to SCC Failure Analysis in Steam Turbines
Failure Analysis Vibration Peaks Steam Turbines (Turbopumps)

505 Controller Module

Hardware Overview and Front Panel
Installation, Power and Startup Basics
Changing Modes and Languages
Installation, Power and Startup Basics
Navigation Screens
Wiring Connections for Analog and Speed Signals
Wiring Connections for Communication Links
Wiring Connections for Discrete Signals
Ethernet IP Address Settings

SST 800 Module

SST 800 Condensing and Backpressure Steam Turbine Details and Systems
Lubrication System – Hydraulic Unit
Lubrication System – Consumers
Control System
Condensing System
Steam System – Condensing Turbine
Steam System – Backpressure Turbine

SST 400 Module

SST 400 Condensing Steam Turbine Details and Systems
Lubrication System – Hydraulic Unit
Lubrication System – Consumers
Control System
Condensation System

Frequently Asked Questions About Steam Turbines

What are the main types of steam turbines?
Condensing, backpressure, reheat, and extraction turbines.
How can I improve the efficiency of my steam turbine?
Regular maintenance, proper steam conditions, and operational adjustments.
What industries benefit most from steam turbines?
Energy, oil & gas, manufacturing, and water treatment.
What is the lifespan of a steam turbine?
Typically 20–30 years with proper maintenance.
Are steam turbines suitable for renewable energy?
Yes, they are widely used in geothermal and biomass applications.
Does TURBIVAP offer customized training?
Absolutely! We tailor courses to your team’s specific needs.

"Steam flows through these components, causing the rotor blades to spin and generate rotational energy."

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Common Challenges and Solutions

Blade Erosion: Caused by high-velocity steam or impurities.
- Solution: Regular cleaning and protective coatings.

Rotor Imbalance: Results from wear or deformation.
- Solution: Dynamic balancing during maintenance.

Seal Leakage: Leads to efficiency losses.
- Solution: Periodic seal inspections and replacements.

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Conclusion

Steam turbines are indispensable in energy production and industrial processes, offering unmatched efficiency and reliability.

To ensure optimal performance, investing in the right training and solutions is crucial.

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