types of turbines

WHAT IS A TURBINE?

Last week, we looked at the history of turbine blades in our “ALL ABOUT BLADES” section. This week, we're going to focus on what a turbine is, how it works, and what makes it different.

A turbine is a machine for continuous energy production, in which a wheel or a rotor, which is usually provided with blades, is rotated by a fast-flowing stream of water, steam, gas, wind, or other liquid. Examples include the Hoover Dam or the mighty Niagara Falls, where water flows through turbines that rotate under the pressure of falling water and generate almost 4.9 million kilowatts, which supply 3.8 million households with electricity. Did you know that there have been 7,254 hydroelectric power plants in Germany as of 2020? Or think of the famous old windmills in Holland, the forerunners of today's wind turbines, which are an effective and cost-effective source of renewable energy to generate electricity.

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DIFFERENT TYPES OF TURBINES

In mechanical engineering, turbomachines are machines that transfer energy between a rotor and a fluid or steam. This includes both turbines and compressors, which are frequently used in the automotive industry (turbochargers), in aerospace (aircraft turbines), in the energy sector (gas and steam turbines) and in industry (compressors).

Turbines can be subdivided according to the direction of flow. The three main areas are radial, diagonal and axial, and the flow medium determines which type of turbine it is. The four main types are steam, gas, water, and wind. All turbines are important and play a big role in industry, but we will only focus on steam and gas, which will lead us to look at the axial and radial flow directions.

What is the difference between axial and radial turbines? In a radial turbine, the flow is oriented uniformly perpendicular to the axis of rotation and drives the turbine in the same way that water drives a watermill. The result is a lower mechanical load (and a lower thermal load in the case of hot working fluids), which means that a radial turbine can be simpler, more robust and more efficient (in a similar output range) compared to axial turbines. In an axial turbine, the working medium flows parallel to the axial compressor of the shaft and converts the flow of the medium into mechanical rotational energy.

All turbines are important, but it is the complex profile of the jet turbine that we measure most frequently.

MORE ABOUT AXIAL TURBINES AND COMPRESSORS

#allaboutblades is essentially about turbine blades, and that's why we want to focus on axial turbomachinery. Axial turbines and compressors consist of several stages. Steps are the combination of a pair of rotating and stationary blades (guide blades). The blades are connected to the rotor, and the guide blades are connected to the cast part. The main function of the blades is to ensure the transfer of energy between the gas and the rotor. The blades, on the other hand, prepare the gas for entry into the next set of rotating blades and divert the flow of the gas flowing through from the previous set of blades to the next set of blades. This results in a flow of compressed air, energy-rich steam or exhaust gas through the turbine/compressor to transfer the largest possible amount of energy.

Axial turbines and compressors are different types of turbomachinery with the same basic principles, only in reverse form. Turbines are fed with energy-rich gas, which flows through the turbine. Step by step, it transfers its energy to the blades. The gas flowing through expands, and as a result, the blades and guide vanes increase in size along the axial flow path of the gas. In the end, all energy is transferred to the blades and thus to the rotor to finally drive another machine. When generating energy in power plants, the turbine is connected to a generator to generate electricity.

A compressor works in the opposite way and is driven by a motor. The air is sucked in by the rotating blades and forced through the compressor. Each set of vanes/valves is slightly smaller, which gives the air more energy and compression.

GAS TURBINES — COMBINING BOTH WORLDS

Aircraft turbines have both a compressor and a turbine, and the combustion chamber is located between them. The air is sucked into the turbine, compressed and mixed with the fuel so that combustion takes place, which results in thrust. In addition, a turbine in the exhaust gas flow is activated by the exhaust gas flow. The turbine impeller is connected to the compressor and therefore acts as a mechanical connecting motor to the compressor, which drives the compressor. However, the main energy of the hot exhaust gas is used to generate thrust by increasing its speed through the nozzle.

This basic principle is also found in turbojet/jet engines, the simplest types of aircraft gas turbines.

Die Turbofan-Gas turbine is the most common type of turbine engine used in aircraft today. The basic principle is the same, but the components are more complex. In addition, there is a fan and a bypass system to further increase the efficiency and stability of the turbine.

Turboshaft motors are commonly used in applications that require sustained high performance, high reliability, small size, and low weight. They find this application in helicopters, auxiliary engines, boats and ships, tanks, hovercraft and stationary systems.

THE STRUCTURE OF THE LEAF

The shovel and wing have different functions but have similar geometric elements. The blade diverts the flow path while the blade transfers energy between gas and rotor. The blades must operate at high speeds and temperatures, while the guide blades conduct the current driven by the rotating blades to the next turbine stage with optimum efficiency. Both the blades and the guide blades must be resistant to oxidation, corrosion and wear and have a long service life.

This is one of the most important aspects that companies have when it comes to Consider improving your shovelsto increase performance and extend the life of the blades.

MEASUREMENT INCREASES EFFICIENCY

The structure and function of the blade consists of three aspects:

1) The root is used to attach the blade to the rotor or housing. Depending on the mechanical load, required fixing precision and manufacturing costs, the roots may be different. We will address this issue again in detail in the future.

2) The blade, which is functionally shaped to ensure proper interaction with the gas flow, is intended to redirect the flow path while the blade transfers energy between gas and rotor. The profile merges into the root and the jacket via a transition radius and a curved platform surface. The profile consists of a print and a suction page with a front and a back edge, which will be part of our detailed blog.

3) The cover band is optional and depends on the turbine's application. Jacketed blades are used to control and minimize leakage flows between blade tips and blades and to limit vibration amplitudes to ensure the creation of a stable outer ring.

WENZEL MEASURES #MOREPARTSFASTER

When manufacturing shovels, there is a wide variety of shapes, dimensions and requirements for every desired application. The profiles are designed to maximize the required performance. Regardless of size, interface, or lead time, CORE has no limitations. The high-speed optical scanning system was developed for the harsh conditions of a direct production environment. CORE M is characterized by temperature stability, dirt and vibration resistance. Highly dynamic linear drives and the robust basic machine of the 6-axis measurement system enable measurements at high speed.

The innovative optical high-intensity light scanner from WENZEL ensures rapid point detection, even on hard-to-reach components and highly reflective surfaces, without time-consuming repositioning of the component or pretreatment of surfaces.

The CORE M has a measurement volume of 500 mm x 500 mm x 2,500 mm and is therefore ideal for measuring large components. Within the machine housing, there is a system of dynamic balancing weights that counteract the forces generated by the high-speed movement of the scanner, so that no loss of accuracy occurs even at remarkably high measurement speeds. WENZEL's extensive software package enables simple and quick evaluations of blades using the WM | Blade Analyzer blade analysis software developed in collaboration with industrial partners.

As you may have already noticed, we love gauge turbine blades with their gunmetal gray and smooth, graceful design. These small pieces have a significant impact, allowing us to travel around the world, build our economy, and protect our countries and loved ones — all of which are good reasons why. I'd like to encourage you to enjoy a relaxing river trip on an old steamboat, marvel at the size of the big wind turbines, visit Niagara Falls, and think about how far we've come over the centuries. Recall that improvements have been made through measurements and that technology has evolved.

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