Difference between the Steam turbine and Gas turbine
Gas and steam turbines have different structures even though they operate on the same concept. They differ in the type of fuel used to power the turbine, and the gas turbine additionally has a compressor that pushes a lot of air into the combustion chamber. The main distinction between steam and gas turbines is that: Gas turbines use an external fuel source, such as natural gas or petroleum gases, while steam turbines only use steam. The hot, expanding gases from burning fuel turn a shaft in a gas turbine engine, which subsequently drives an electric generator.
Steam Turbine:
A steam turbine is a device that uses pressurized steam as a heat source and recovers thermal energy from it to drive mechanical work on a revolving output shaft. Charles Parsons created it in its current form in 1884. Modern metalworking processes are used to construct steam turbines; which was first made possible in the 20th century. The continuing improvement of steam turbines’ resilience and efficacy are still essential to the energy economics of the 21st century.
The utilization of many stages in the expansion of the steam, which results in a closer approach to the ideal reversible expansion process, is a major contributor to the steam turbine’s gain in thermodynamic efficiency. Since a turbine generates circular motion, it can be utilized to power an electrical generator. In 2014, steam turbines provided around 85% of the electricity used in the US. Combining a steam turbine and an electric generator yields a turbo generator.
Why does steam contain so much energy?
If you’ve ever burnt yourself with steam, you know how painful it is—much more excruciating than a burn from regular hot water. Why does steam hurt more when water is at the same temperature? just because it has a lot more vitality. The amount of energy required to convert 1kg (2.2lb) of water heated to 100°C (212°F) into 1kg of steam at the same temperature is around 2257 kilojoules or nearly 1000 times the energy that an electric kettle or toaster uses in one second. That is a colossal amount of energy! We refer to it as the latent heat of water vaporization.
When 100°C boiling water strikes your body; it cools and then releases heat that causes you to get burned. When 100°C steam comes into contact with your body, it initially condenses back into the water before cooling down, burning you similarly to hot water while also transferring the latent heat of vaporization to your body. A steam burn is far more serious and painful than a hot water burn because of this extra significant amount of heat energy. On the plus side, steam’s latent energy, which is “hidden,” is what makes steam engines and steam turbines so effective!
Working Principle of Steam Turbines:
We are now aware that a steam turbine relies on steam pressure to operate. It is preferable to start with examining the steam’s composition because it is the most crucial component of a steam turbine in order to understand how it operates. These pieces of machinery function according to the dynamic motion of steam.
Greater pressure steam coming from the nozzle is impacted by the snug-fitting disc on the shaft’s revolving blades. The device’s blades acquire energetic pressures as a result of the higher steam velocity, which causes the shaft and blades to rotate uniformly.
The jet engines dissipate the stem’s energy before it is converted to kinetic energy and sent through the tube. Since the rotor has a connection to the steam turbine generator and works as a middleman, the change in kinetic energy causes mechanical motion in the rotor blades.
Due to their efficient construction; devices generate the least noise as compared to other rotating machinery. The majority of turbines have a linear relationship between the speed of the rotating blades and the speed of the stream going past them.
- Compressed steam from a boiler serves as the steam turbine’s operating fluid.
- As the superheated steam entering the turbine loses pressure (enthalpy) while passing through the blades of the rotors; the rotors rotate the shaft to which they are connected.
- The thermal efficiency of a steam turbine is higher than that of a reciprocating engine but lower than that of gas turbine engines due to the higher operating temperatures of the gas turbines (Gas turbines 1500°C and steam turbines 550°C). Steam turbines produce electricity at a steady, consistent rate.
- Although steam turbines are primarily utilized today to generate electricity; they were once the dominant source of power for ships and locomotives around the turn of the 20th century. As an exception; steam engines are still employed in some marine propulsion systems; such as those on aircraft carriers and submarines; where diesel engines are unworkable.
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Gas Turbine:
A gas turbine or combustion turbine is a continuous flow internal combustion engine. The power-producing component of gas turbine engines; also referred to as the gas generator or core; is made up of the following primary components; listed in the order of flow:
- a combustor,
- a compressor-driving turbine,
- and a revolving gas compressor.
The gas generator needs to have extra parts to fit its intended use. An air intake is a feature that all have in common, although they are all configured differently to meet the needs of flying at different speeds, from supersonic to stationary to land use. The addition of a propelling nozzle provides thrust for flight. At subsonic flying speeds; An additional turbine powers a turboprop or ducted fan.; which reduces fuel consumption (by improving propulsive efficiency). A second turbine is also necessary to power an electrical generator, a maritime propeller, a land vehicle’s turboshaft, or a helicopter’s rotor (power turbine). The inclusion of an afterburner increases the thrust-to-weight ratio for flying.
- A gas turbine, or just a gas turbine, is an internal combustion engine that operates on gases like air.
- the compressor, combustion chamber, and turbine in a gas turbine engine as opposed to a steam turbineare assembled along a rotating shaft to perform various operations of an internal combustion engine.
- Gas turbines can be used to generate thrust; or a combination of the two (which drives military fighter aircraft) (used in turboprop engines).
- Because they may use a variety of fuels and working fluids, gas turbines are more flexible. It is readily available and requires constant feeding (air).On the other side, steam turbines need a lot of water to operate and frequently have issues in colder temperatures because of ice.
- These engines are favored above others; especially reciprocating engines; due to their greater durability and superior power-to-weight ratio. Low vibration, quick working speeds, and high operating rates.
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How does Gas Turbine work?
A gas turbine is a combustion engine at the center of a power plant that may transform mechanical energy from natural gas or other liquid fuels. This power then propels a generator, which creates the electrical energy that travels via power lines to residences and commercial buildings.
Which gas does a gas turbine run on?
Although liquefied natural gas (LNG) or natural gas is the fuel of choice for roughly 90% of gas turbines globally due to its purity and ease of combustion; despite frequent claims to the contrary.
Gas Turbine Parts:
