The world of engineering is complex. Various tools and equipment are built and each of them fulfills a specific purpose. A turbine comprises a set of blades that are mounted on top of a rotor. Now, this helps to extract the kinetic energy from the working fluid and convert the same into electrical or mechanical energy. How useful a turbine is, depends hugely on the design of blades that are put in the turbine.
Turbines have different applications and on the basis of applications offered by turbines they are divided into four key categories:
- Water Turbines
- Gas Turbines
- Steam Turbines
- Wind Turbines
- Water Turbines
Water turbines are used in hydroelectric power plants. In such turbines, water is used as the working fluid. To start on, a huge amount of water is collected inside a water reservoir. The bigger the height of the reservoir the greater is the water pressure. This pressurized water is then made to flow through a big pipe. This pipe is referred to as penstock.
The turbine is put at the rear end of the penstock. When pressurized water hits the turbine blades at high speed, it makes the blades rotate rapidly. This turbine is ultimately linked with a generator and this leads to the generation of electricity. The shape of the turbine blades is dependent on the speed of water and the pressure. Water turbines fall into 2 categories i.e. Reaction type and Impulse type.
- An Impulse turbine- This is driven by several jets of water or a very high-velocity jet of water. There are 3 key kinds of impulse turbines are the Turgo, the Pelton, and the Crossflow turbine.
- A Reaction turbine- In this kind of turbine, the rotor is immersed inside water. It is put inside the pressure casing. Profiling of runner blades is done in such a way that the differences in pressure across the blades impose lift forces. This is usually seen in aircraft wings. This causes the runner to rotate at a faster pace than what can take place with a jet.
- A Gravity turbine- This works as per the weight of water that enters the top of the turbine and then what falls to the bottom. This is where the same is released. These are basically very slow-running machines.
For a very long time, Archimedes Screw is used as a pump, but it has been recently that it is put to use in a reverse manner. Now when we use it that way it becomes a turbine. The principle of operation is the same as that of an overshot waterwheel. The shape of the helix enables the turbine to rotate at a fast pace. The power conversion is very high i.e. more than 80%. However, in comparison to other turbines, it is still a slow-running machine. This is the reason why a multi-stage gearbox is put inside it. The main benefit of the Screw is that it precludes the requirement for a clean screen along with an automatic screen cleaner. All the debris can comfortably pass via the turbine. What’s more Archimedian screw is deemed as a ‘fish-friendly’ turbine.
- Steam Turbines- These are used in thermal or nuclear plants. The water is first heated in order to create steam. And this then flows via the turbines to create electricity. Just like water turbines, steam turbines also fall into two categories- reaction type and impulse type. However, the design as well as the arrangement used is different. Most of the contemporary steam turbines are an amalgamation of reaction and impulse type.
- Gas Turbines- Theseare also referred to as internal combustion engines. They are not just put in power plants; they are also used to propel helicopters and airplanes. The rotating blades suck in a big amount of air. The air is then compressed and then increases the temperature. The air is supplied to a combustion chamber. The fuel is added to it and with help of an ignitor the fuel is ignited. A huge amount of exhaust gases are produced and these gases flow via the turbines.
Different kinds of jet engines are mentioned below:
- Water Turbines- These are the gift of engineering to mankind. Out of different electrical tools that are used, water turbines are highly beneficial. They clean, affordable, and sustainable. They can produce a power of 50MW. The rotor of the water turbines has three blades. It is built in such a way that wind goes through it and the blades start rotating at a fast pace.
The sole issues with wind turbines are that they rotate at a low RPM. So, the electricity of the required frequency is not produced. This is the prime reason why a gearbox is needed to escalate the velocity with which the shat moves. The output that the shaft generates is linked with a generator.
The three different types of wind turbines have been mentioned below:
- Savonius vertical-axis wind turbine i.e. Savonius VAWT
- Horizontal-axis wind turbines i.e. HAWT
- Darrieus vertical-axis wind turbine i.e. Darrieus VAWT
Wind turbines are extremely useful and they are increasingly being used in current times. So, these are different kinds of turbines that are being used. Depending on their application they are put to different uses.