The component and functions of the APR1400 Turbine System

The APR1400 Turbine System:
Name:
Institution:
Turbines have been around for decades. The big wooden wheels that were used in sawmills in the early centuries are a simple example of a turbine. Following a century of continuous invention and refinement, turbine system continues to be the world’s leading power generation source which generates over 80% of the world’s energy and electricity. Hence, the APR1400 turbine system that was created by GE and Doosan is another new step in the right path of technologies’ advancement. Having its origins from Korea, the APR1400 employs the biggest ever 60 Hz steam turbine system (modernpowersystems.com, 2008).
For over two decades now, GE a Korean manufacturing company has partnered with Doosan, which was formerly known as Korea Heavy Industry Construction Company (KHICC) to produce steam turbines for the Korean market. In the same time span, other steam engines were also built including the 16.1 MW GE turbine system which was fired by coal as well as the 2.4 GWe combined cycle and the 10.4 GWe nuclear systems (modernpowersystems.com, 2008). This shows that turbine and nuclear energy system have been the backbone of the Korean nuclear energy. Therefore power systems continue to play a huge part in Korea and the world as a whole, giving the option of producing and using energy without polluting the air with carbon dioxide and other toxic emissions which eventually play a significant role in reducing the adverse effects of global warming (modernpowersystems.

com, 2008)
With this in mind, Korea commenced the Korea Next Generation Reactor KNGR) program, with the sole intention of creating larger nuclear power plants that will have greater performance, updated and improved control and operation. This then resulted to the new Advanced Power Reactor (APR) 1400, which is a high and improved Pressurized Water Reactor (PWR) that contains a thermal capacity of 4000 MWt (modernpowersystems.com, 2008)
This article will outline the basic concept of turbine systems, their purpose, the different types of turbine systems and how they differ, the components of turbine systems and their functions and finally compare the turbine system in the APR1400 and the OPR 1000.
Basic Concepts of the Turbine system
The basic idea of any mechanical machine including turbines is simple. A propeller system is the main part of these devices where fluid or gas enters the system at a certain speed with a mass flow added at a certain rate to make the propeller spin to achieve the desired result. This could be moving an object like a plane, a boat or a locomotive engine, or a power plant which taps certain kinds of energy to produce hydroelectric power (stanford.edu, 2016). Turbines are used in many different types of generating energy. For example, production of solar energy, coal- fired, nuclear, biomass, and gas.
The different types of engines
Rockets: These use gasses emitted by an exhaust pipe and other fuels found in the rocket combustion. Small amounts of gas (Mercury) are surged into an electric environment to produce thrust (stanford.edu, 2016).
Ramjets: These are engines that use ambient air. Air is blown into an inlet of the engine at very high speeds and then it is compressed as it is slowed down. This air gets mixed with the fuel and then it is burnt in the combustion chamber and finally released through the nozzle of the jet (stanford.edu, 2016).
Turbo Jets: These are engines that allow for more than one compressor to be added to it when more compression is required. This was a concept that was used till the early 1950s. A more revolutionary form of compression was incepted to increase the amount of pressure ratio using different stages of compression. For instance, for turbojets, a windmill is put in the exhaust on the “in” part of the exhaust to help it withdraw power from the shaft (stanford.edu, 2016).
Turbo fans: These are engines that are required to be very efficient at slower rates of propelling. Fans need air to function and turbofans require a lot of air to function as well. Therefore, turbofans use different types of methodologies to withdraw power. They use both air and fuel at equal proportions. This can be done by channeling the air and fuel through different routes hence bypassing the core of the engine (stanford.edu, 2016).
Turbines and their basic concept
Turbines are machines that are formed and designed to catch energy through a moving liquid or gas so that it can be used the highest percentage of electricity In the world. The whirlwind and water turbines assist in producing renewable energy. Turbines function through using steam, and one will find a turbine in almost every major power plant. Therefore, anywhere there is a community or a group of human beings living in that area, there is always a turbine somewhere in the vicinity (Woodford, 2016).
A windmill, for instance, is the simplest example of a turbine. When the wind blows the mills, sails go round absorbing that wind and use it as kinetic energy. It converts this energy into mechanical energy that is used to move heavy stones within the mill. As the wind blows faster, more mechanical energy is produced for and by the mill (Woodford, 2016).
Parts of a Turbine
The most important parts of a turbine are sets of blades which catch the fluid that is in movement, a shaft which goes round as the blade moves, and a machine that is moved by the shaft (Woodford, 2016).
How Turbines Work
The Impulse and the reaction turbine work in two major ways.
Impulse Turbines
In these impulse turbines, the fast moving fluid is released through a thin nozzle located at the blades to enable them to go round. The blades of such a turbine are shaped like a bucket such that they can capture the fluid and move it in a certain angle or backward as it came in. This fluid is made to hit the turbine with very high speeds. Water turbines are mostly developed as impulse turbines. Impulse turbines have a very simple design, therefore very easy to assemble, and are relatively cheap to maintain (Woodford, 2016).
Pelton: A Pelton wheel consists of one or several jets that discharge water into a space supplied with air. Draft tubes are not a necessity as the runner is mostly situated at high tail water positions to allow for atmospheric pressure to operate (energy.gov, 2016)
Cross-Flow turbines
A cross flow turbine has the shape of a drum and uses long rectangular shaped nozzles that are angled in vanes that are round. The word cross comes from the fact that it allows water to flow through it twice. The first phase has water flowing from the inside to the outside of the blades and the second is from the inside and then back out. A vane that acts a guide directs the flow of water to the runner. The cross-flow turbine was created to handle large amounts of water flow and has a lower head than the person (energy.gov 2016).
Reaction turbines
Reaction turbines consist of blades that occupy a much larger amount of fluid than impulse turbines. These blades go round as the fluid moves or flows by. The reaction turbine does not change the fluid’s direction to a certain angle or send it back the route it from whence it came like impulse turbines (Woodford, 2016). Reaction turbines are mostly made for places with low heads and high flows as opposed to the impulse turbines that are the extreme opposite (energy.gov 2016).
Propeller turbines
These consist of a runner that has between 3 to 6 blades, and the water is meant to contact all the blades periodically. The pitch on the blades can either be set to be fixed or an adjustable one. They comprise of a scroll case, a draft tube, and a wicket gate. Under propeller turbines, there are other different types of turbines;
Bulb Turbine: This is where the generator together with the turbine are sealed and then set directly in the stream of water.
Straflo: This is where the generator is placed next to the turbine perimeter.
Tube Turbine: A penstock bends right before and after a runner to allow for a straight connection to the generator.
Kaplan: This has the two blades and the wicket gates to allow for a vast range of operating.
Francis: This turbine consists of buckets of more than nine fixed vanes. Water is then allowed to flow above and around the runner and then it falls through making it spin. (energy.gov 2016).
Kinetic: These are also known as a free -flow which produces or generate electricity through kinetic energy found in water that is flowing. It works, in rivers, man-made dams, oceans, tide waters and oceans with the current. They make use of the natural path of water flow and do not need water to be diverted to certain angles by mad man efforts like river beds or even pipes. They do not need a lot of civil work and can use already existing structures like bridges, channels or tail races. This makes kinetic turbines the easiest kinds turbines to build and install (energy.gov 2016).
Backward Thinking
Turbines look like giant propellers working backward. For instance, when the engine of an airplane starts, it turns on the propeller at very high speed, and this makes it produce a backward movement air, and that helps to push the plane forward. Therefore when a propeller is present, its blades help to move the air, but with such a turbine, there is air is moving the blades (Woodford, 2016).
Turbines may also be likened to pumps or compressors. A pump has a spinning paddle which sucks water into it via one pipe and pushes it out through another pipe, to have the ability to move water from one point to another. When the water is separated, one can see the paddle wheel called the impeller inside. This is almost the same as what one would find in water turbine. The pump uses energy to make the fluid move, but a turbine takes energy from the fluid that is moving (Woodford, 2016).
Turbines at Work
Turbines are divided into four categories, and this depends on the type of fluid that gets them moving. These are the wind, water, steam, and gas. These four types of turbines generally work in the same way where they move around as the fluid passes through or against them. But they are also very different regarding how they get engineered. For instance, turbines that use steam move around very fast because the steam is released under very high pressure. On the other hand, wind turbines which are used to make electricity turn at much slower speeds basically due to safety reasons. This necessitates the need to make them huge to make them absorb a lot of energy to function (Woodford, 2016). For gas turbines, their alloys need to be made from very strong steel as they are exposed to very high temperatures. Water turbines are the largest as they need to get energy from a whole river. Therefore the rivers are purposely diverted to flow through them. Water turbines like the gas turbines are also slow because the water is very heavy regarding mass even when its flow is not high (Woodford, 2016).
Water turbines
Water turbines go way back 2000 years ago to the Greek age. However, the same concept has been used to make produce electric power in power plants. The basic principle is always to convert a river into a dam to utilize its energy. This happens when water is made to fall from a certain specified height known as a head so that it can gain momentum, and pick potential energy, which is then converted into Kinetic energy, instead of the natural way where it falls from a hill or a mountain freely (Woodford, 2016).
A variety of water turbines could be used, and this depends on the area that the river flows from, the quantity of water present, together with the distance at which it could be converted into a head. Hydroelectric plants use various types of turbines, e.g., Francis, Kaplan, or Diaz reaction turbines. This is all dependent on the above factors to ensure that the maximum amount of energy is extracted and utilized (energy.gov 2016).
Water turbines work almost the same as fuel power plants in that they use a turbine that spins a metal shaft in a generator (reference.com, 2016). Water turbines are also called hydropower plants because they use water to produce and generate electricity. The turbines use kinetic power energy of moving water. Water is frequently moving around us through evaporation from lakes, rivers and oceans, which are converted into clouds then water falls as rain and flows back to the ocean to begin the same process again. This process produces energy which is motivated by the sun, and this energy is tapped to benefit humankind like producing electricity or for mechanical activities like manufacturing products (energy.gov 2016). Hydropower is considered a renewable energy because none of the fluids used in the process get used up. As we have also seen above, the cycle of getting water is an endless one.
How hydroelectric turbines work
A hydropower plant transforms the energy of natural moving water into electric energy. (kinetic energy) But for this to happen, it will need a machine that will be able to transform this energy into mechanical energy, and this is where the water turbine comes in. This turbine has got big blades with curves that can withstand the pressure and motion of the moving water. This turbine is known as the Francis turbine, and it is the commonly used type of water turbine (reference.com, 2016).
The process of converting mechanical energy into electrical energy requires a revolutionary force. This is mostly achieved through the use of a generator. And that is why generators are placed at the very top of the shaft which is connected to the water turbine. As water is flowing, the turbine catches the water with its blades, and this causes the blades to spin around. The generator acquires the needed force and can generate electricity.
Hydroelectric power plants depend on the natural amount of water drops originating from a powerful river. These drops facilitate the flowing water to be captured into the turbine through a penstock This moving water moves and spin the propeller. And then field loops of wire are put around the steel made of the magnet and then it is put around the rotor. As water flows through, the rotor moves around at a certain speed; then the magnetic poles are move beyond the conductor.This then produced electric power through the outer terminals. Therefore, it is always important to ensure that there is plenty of flowing water behind the power turbine to enable it to function efficiently. Hydroelectric power is the only form of the electric producing version that is clean and environmentally because it originates from nature (reference.com, 2016).
The impulse version of water turbines uses water to move the runner. After reaching the runner, water flows out of the turbine section. Reaction turbines, however, use both flowing water and pressure. In this case, the water does not have to reach and hit every blade of the turbine but hits the runner directly. This has made reaction turbines more popular and available than impulse turbines. This is because of the double benefit of the ability to use both water and pressure. Therefore water is used efficiently. When the water flow reduces due to natural reasons, the pressure is still “able to maintain the functionality” of the water turbine (reference.com, 2016).
Wind Turbines
Wind turbines are the long white poles with turbines that go around with the intensity of the wind which makes them look like airplanes moving on the spot. In these moving turbines, there is energy captured and locked in there and then it is converted into electricity (Woodford, 2016).
How wind turbines generate electricity
The big blades in front of the wind turbine are the part with the turbine. They are curved in the shape that looks like airplanes wings. The Wind blows past an airplane’s wings, and this pushes them up with a force that is called a lift, as the wind blows past the turbines, it makes them spin around. This makes the wind lose some of its energy (kinetic), and the turbine acquires an equivalent amount of energy. The variations of wind determine the amount of electricity produced. Therefore, several numbers of wind turbines are placed together in a farm which helps in combining the energy hence producing large volumes of electricity.
For a wind turbine, the longer the rotor blades, the more energy they can get from the flowing wind. These blades help to multiply the force of the wind therefore even a little breeze of wind can make the blades spin. However, wind turbines are stationary almost 15 % of the time, therefore, are not able to produce enough power. (Woodford, 2016). A normal wind turbine is 85 meters long, and this is mostly for a reason. The Wind always travels faster in places where there are no obstructions like tall buildings, trees, or hills. Therefore, for wind turbines to capture the maximum energy, they must be high above all the distractions on the ground level. (Woodford, 2016).
Two types of wind turbines exist. These are the horizontal axis and those with a vertical axis. Most of the wind turbines are the ones with a horizontal axis. These are further classified into upwind turbines where the wind hits the blades before it hits the tower and the downwind where the wind hits the tower before the blades. Upwind towers consist of a yaw drive, as well as a motor which are gadgets that help to keep the rotor in the direction of the wind by turning the nacelle every time the wind changes direction (energy.gov 2016).
Vertical axis turbines remain a foreign concept to the world market, and manufacturers are yet to produce them in a higher percentage, unlike the horizontal axis. However, vertical axis also has two main categories of design, i.e. the Drag-based, or Savonius turbines which have rotors with hard vanes that spin around a vertical axis, and the Lift-based, or Darrieus, turbines which have a long, vertical airfoil make up. Some also seem to have the egg beater design.
Wind turbines seem to still have a long future ahead and therefore efforts are being made by existing governing states to ensure more modern, reliable and efficient turbines are easily accessed in the market at a fair price. The Wind program council has worked to ensure that the capacity of the wind turbines is increased in the market as they promote the green energy campaign (energy.gov 2016).
Steam Turbines
Steam engines burn charcoal openly so that it can release the heat it contains. This heat is then used to boil water which creates the steam. This steam pushes a piston located in the cylinder to power machines likes train locomotives. Steam engines were first incepted by Engineer Charles Parsons, a British engineer who used steam engines to power a motor boat known as the Turbines in the 1800’s. They are now used in various ways. For instance, power plants produce electric power using steam engines. In contrast with the water and wind turbines, steam turbines have several numbers of turbines called stages that are arranged sequentially in a pipe that is closed. The steam enters through these pipes and then it is directed through each stage in a progressive manner to get as much energy as possible. This makes steam turbines to be the fastest to run compared to wind and water turbines. (Woodford, 2016).
Steam turbines have similar blades to a wind turbine which go round when steam blows across them. Like a water turbine, the blades are placed in a sealed container to contain the steam and force it through the channel at high speed. Steam turbines use very high-pressured steam to propel electricity generators at very high speeds. Therefore, they rotate faster than the wind and water turbines.
Parts of a steam turbine
Rotor and blades: the rotor is found at the center of the steam turbine that transfers the power away from the turbine into the machine the turbine is meant to operate. This could be a generator or a rail locomotive. The blades make the most important equipment part of the turbine and are therefore designed very carefully. This is because their design determines the amount of energy that is extracted from the steam. This energy is what is used to spin the rotor. The rotor and steel are made of alloy steel case which helps in protecting them from the effects of exposure to high temperatures (Woodford, 2016).
Apart from the rotor and the blade, there are other important parts that the steam engine needs, and this includes a steam inlet that looks like a nozzle that helps to channel the steam to the required destination. One will find most steam turbines in big power plant settings which are driven by very big furnaces and therefore becomes very difficult to control or reduce the amount of heat reduced. Therefore a control mechanism will help to deal with the fluctuations of the heat released (Woodford, 2016).
In the real sense steam turbines are more complicated than we have described so far. For instance, instead of having one set of rotor blades, there are normally some sets, and they help to maximize the amount of energy extracted. Each set is called a stage, and they work by an impulse or reaction. And a turbine can have a mixture of both all put on the same rotor and are made to turn the machine at the same time. The impulse phase happens before the extraction stage. (Woodford, 2016).
Condescending and now- condescending
Steam turbines are also different in the way that they cool the steam that goes by and through them. Condescending turbines which are mostly found in huge power plants that produce electricity partially transform the steam into water using the cooling equipment. This helps the steam to expand creating an environment for the turbine to extract more energy from it and this further helps the electricity to be processed much smoother. A huge amount of cold water is required to be present all the time to cool the steam. This explains why many hydroelectric plants are stationed near a natural water river. On the other hand, the noun- condescending turbines do not cool the steam but use the heat to heat water, and this is called combined heat and power (CPH). Steam turbines come in all shapes and sizes and also produce different levels of power (Woodford, 2016).
Gas Turbines
A gas turbine is an engine that can convert natural gas or other liquid fuels into mechanical energy. The mechanical energy is then used to drive the equipment to produce the desired result, for instance, driving a generator to produce electricity.
How a gas turbine works
To produce electricity, the gas turbine heats a mixture of air and fuel at a high temperature making the turbine blades to go round. This movement makes the generator convert kinetic energy into electric power (powergen.com, 2016). A gas turbine is comprised of 3 sections:
The Compressor, which pulls air into the engine, puts pressure on it and then transfers it to the combustion chamber at very high speeds (energy.gov 2016).
The combustion system: This is made up of circular fuel transmitters that transmit fuel into the combustion chambers so that it can be mixed with air. This mixture is then burnt at very high temperatures, and high-pressure gas is produced and released through the turbine section (energy.gov 2016).
The turbine: This is comprised of nonmoving aerofoil blades. Hot gas from the combustion chamber expands in the turbine forcing the blades to rotate. This rotation performs two tasks
It pushes the compressor to acquire more pressurized air into the combustion part, and then
It rotates the generator causing it produce electricity.
There are also land-based gas turbines that are in two forms.
i. Heavy frame engines
Heavy frame engines have low-pressure ratios and are large physically. Pressure ratio is defined as the ratio of the pressure that is released in and out from the compressor.
ii. Aero-derivative engines.
From the name, aero-derivative engines are taken from jet engines and function at very high-pressure ratios. These are used in places where a small amount of power or energy is required (energy.gov 2016).
To be able to tell an efficient steam turbine, it must have the ability to operate and function at very high temperatures. This is because high temperatures represent efficiency in the turbine energy language which also means that the operation will be economical in all aspects. Gas that flows through a normal steam turbine ranges from 2000 degrees F. This is where the energy program was able to achieve a breakthrough when they surpassed previous impediments on turbine temperatures using modern technology and innovation through cooling equipment and modern raw materials. They then produced turbines that were able to withstand temperatures of as high as 2600 degrees F (energy.gov 2016).
Another way to enhance efficiency is to put a heat recovery mechanism to recover energy that is being wasted as it is released through the exhaust pipe.For instance, a heat recovery steam generator. This equipment can take wasted heat from the exhaust section. This recovered heat is used to add on to the overall electric power produced (energy.gov 2016).
A simple gas turbine setting can produce up to 30% of energy conversion. And with the breakthrough from the energy program, the future is bright for gas turbines especially with the breakthrough of wasted heat recovery mechanisms.
Comparison between the APR1400 and OPR 1000
They APR 1400 is an advanced form of light water reactor, (LWR) that was developed in 2002 in the Korean nation. The design was largely influenced by the Optimum Power Reactor of 100 MWe ( OPR 1000), which was the very first water reactor in Korea. The APR1400 uses modern technology and includes several features of design to meet the economic needs of the modern world as well as meeting the new safety rules and regulations to improve safety in the power plants (aris.iaea.org, 2016).
In the 1980s Korea introduced an independent technology program that handled every aspect of owning and operating a nuclear power plant construction project. This was made possible through the OPR1000 design and construction projects. As of August 2010, Korea had a total of 8 OPR1000 that were operating at optimum efficiency while there are four units of modern OPR100 that are in the construction phase. This helped set the bar in internationally through the accumulation of design, technology, construction, operation and maintenance. The APR1400 design was developed in 1992 and was completed in 2002 after 2 years of the research process. The PWR designs were being developed around the world, therefore, called for a review. In the review process, safety and performance goals were incepted to meet the demands of ALWRS in the future (aris.iaea.org, 2016). The APR1400 system is an evolved version of the OPR 1000, but the basic form of configuring the equipment is still the same. There have been some advancements made to the APR1400 as a way to evolve and modernize turbine technology (aris.iaea.org, 2016).
Advancements on the OPR1400
The direct vessel injection has been changed from the safety injection vessel, changes have been made in the passive flow of the regulator in the safety injection tank, the water containment supply system, the depressurization system has been advanced and modified to safety, and other accident response and management system. The main control room is newly designed with a human factor of engineering in mind. It has the full digital equipment and I&C systems (aris.iaea.org, 2016). The new and improved reactor coolant system has increased thermal margin, it burns up to 555,000 MWD/MTU, It economizes neutrons, has increased resistance and now has a filter nozzle (Gon, 2016)
Both the APR 1400 and the OPR100 are designed with a double solid tandem compound design with one HP and three other turbine segments. They also rotate with a speed of 1800 rpm because of the high rate of flow which consists of a double looped Pressurized Water Reactor. They also have got four reactor cooling loops.
Conclusion
The energy sector has evolved and with the introduction of newer and advanced forms of the different types of turbines, energy will be harnessed and therefore be able to provide more power and energy and overall positive service to human beings. However, some types of energy producing turbines, like the gas and fuel turbines, they have contributed to global warming and the effects are being felt by every living creature. The effects of global warming have also contributed to the shortage of more environmentaly friendly turbine usage like the hydroelectric power plant, which operates through the use of water turbines. There has been shortage of sufficient water to run these turbines. And this has encouraged even more use of the toxic and harzadous forms of energy producing methods. Nations like Korea have set an example by taking very positive steps in ensuring that they build power plants that are more environmentaly and human-friendly. This brings hope not only to the environment but to other nations around the world. It is important for other nations intending to build energy-producing power plants will get on board and ensure that they also build modern plants that are approved by the energy program. The energy program is recognized for its efforts to ensure that they manufacture and avail cheap and safe turbine equipment in their quest to encourage nations to make use of the natural resources available in their areas.
References
aris.iaea.org,. (2016). Status report 83 – Advanced Power Reactor 1400 MWe (APR1400) (1st ed.). Retrieved from https://aris.iaea.org/sites/..%5CPDF%5CAPR1400.pdfenergy.gov,. (2016). Types of Hydropower Turbines | Department of Energy. Energy.gov. Retrieved from http://energy.gov/eere/water/types-hydropower-turbinesGon, K. (2016) (1st ed.). Retrieved from https://www.iaea.org/NuclearPower/Downloadable/Meetings/2011/2011-07-04-07-08-WS-NPTD/6_KOREA_APR1400_OPR1000_KHNP_Kim.pdfmodernpowersystems.com,. (2008). Korea’s APR1400 employs largest ever 60 Hz steam turbine – Modern Power Systems. Modernpowersystems.com. Retrieved from http://www.modernpowersystems.com/features/featurekorea-s-apr1400-employs-largest-ever-60-hz-steam-turbine/powergen.com,. (2016). HOW A GAS TURBINE WORKS. Retrieved from https://powergen.gepower.com/resources/knowledge-base/what-is-a-gas-turbine.htmlreference.com,. (2016). How does a water turbine work?. Retrieved from https://www.reference.com/science/hydroelectric-energy-work-7e985d0129d8d1e8#stanford.edu,. (2016). Propulsion Systems: Basic Concepts. Adg.stanford.edu. Retrieved from http://adg.stanford.edu/aa241/propulsion/propulsionintro.htmlWoodford, C. (2016). How turbines work | Impulse and reaction turbines. Explain that Stuff. Retrieved from http://www.explainthatstuff.com/turbines.html