Steam turbines are essential devices in the transformation of thermal energy from steam into mechanical or electrical energy. They play an important role in the generation of electricity in thermal and nuclear power plants. However, many people do not know what a steam turbine is or what its parts are.
Therefore, we are going to dedicate this article to tell you What is a steam turbine and what are its main parts?.
What is a steam turbine
A steam turbine is a machine that converts high-pressure steam energy into rotary mechanical energy. This process is carried out by expanding the steam through a series of blades mounted on a rotor, which generates the rotary motion.
The operation of a steam turbine is based on thermodynamic principles. First, steam is generated in a boiler, where water is heated to become steam at high pressure and temperature. Then, this steam is directed to the turbine, where it passes through stages of fixed and moving blades that redirect and transform the steam energy into mechanical work.
Parts of a steam turbine
A steam turbine is made up of several main parts, each with a specific function to ensure its efficient operation. Although there are many types of turbines, they all have a few main components.
- Housing (turbine body): It is the outer structure that encloses and protects the internal components. It also serves to contain the steam and direct it to the correct areas within the turbine. The casing is designed to withstand high pressures and temperatures.
- Rotor: It is the main shaft of the turbine to which the moving blades are mounted. The rotor rotates when steam flows through the blades, transforming the steam's energy into rotary motion.
- Blades or vanes: There are fixed blades, which are attached to the casing and redirect the flow of steam towards the moving blades, and moving blades, which are mounted on the rotor and are those that receive the direct thrust of the steam, generating the rotary movement.
- bearings: These are mechanical elements that support the rotor and allow it to rotate smoothly and stably. There are support bearings and thrust bearings, which ensure the axial position of the rotor and minimize friction.
- Steam seals: They prevent high-pressure steam from escaping from the turbine through the connections between the rotor and the casing. This ensures that the steam energy is used efficiently.
- Control valves: They regulate the flow and pressure of the steam entering the turbine. These valves allow the generated power to be adjusted according to the system demand.
- Condenser: Although not a direct part of the turbine, the condenser plays an important role by cooling the steam after it passes through the turbine, converting it back to water for recirculation into the system.
- Lubrication systems: They ensure that the moving parts of the turbine, such as the rotor and bearings, operate smoothly and without excessive wear.
- Air extraction system: In condensing turbines, this system removes air and non-condensable gases that could reduce process efficiency.
What is a steam turbine used for?
Steam turbines have a wide variety of applications due to their ability to efficiently transform steam energy into mechanical or electrical energy. The main purpose of a steam turbine is to convert the thermal energy of steam into rotary mechanical energy. This mechanical energy can be used in two main ways:
- To generate electrical energy
- To supply mechanical energy directly
In most power plants, the steam turbine is connected to an electric generator. The rotary motion of the turbine rotor is transferred to the generator, which converts this mechanical energy into electricity. This is the most common use of steam turbines in the world.
In certain industrial processes, steam turbines are used directly to drive machines, such as pumps, compressors or propulsion systems. This eliminates the need to convert energy into electricity, making it more efficient for specific applications.
Areas of application of steam turbines
Steam turbines are used in many industrial areas as they are a fundamental part of electricity generation. Let's look at some of the most commonly used areas:
- Thermal power plants: They use fossil fuels (coal, natural gas or oil) to heat water and generate steam. The steam drives the turbine, producing electricity.
- nuclear power plants: In these facilities, the heat needed to generate steam comes from nuclear reactions in the reactor. The steam turbine is the link between nuclear energy and electricity generation.
- Geothermal plants: They harness the natural steam from the Earth's interior to power turbines, generating electricity sustainably.
- Industrial processes: In chemical, petrochemical and refinery industries, steam turbines drive compressors and pumps that are essential in processes such as distillation, refrigeration and gas compression.
- Paper production: Steam turbines are used in paper mills to power heavy machinery and generate the heat needed to dry paper.
- Boat propulsion: In the past, steam turbines were common on large vessels, including cruise ships and military ships, as they offered power and reliability. Although they have been partly replaced by diesel engines, they are still used in some cases.
- Cogeneration: In installations where electricity and heat are needed at the same time, steam turbines make it possible to use the residual thermal energy of the process for heating or industrial processes.
- Renewable energy: In solar thermal power plants, mirrors concentrate sunlight to heat a fluid that generates steam, which drives the turbine.
As you can see, the steam turbine is one of the most important elements in the generation of electrical energy in many industrial areas. I hope that with this information you can learn more about what a steam turbine is, what it is used for and what its main parts are.