A power plant when viewed from raw material to produce it, then Fired Power generators can be said is made raw water. Why not STEAM? Steam power player here only as a turbine, while steam to produce a certain amount of water needed. Interestingly in the power plant there is a continuous process of ongoing and repetitive. The process of water into steam and then steam back into water and so on. This process is a cycle power plant.
Water used in power plant cycle is called Demin Water (Demineralized), ie, water that has levels of conductivity (the ability to conduct electricity) amounted to 0.2 us (micro Siemens). As a comparison of mineral water we drink everyday has a conductivity level of about 100-200 us. To get this demin water, every power plant units are usually equipped with Desalination Plant and demineralization plant which is used to produce this demin water.
In simple terms how to cycle power plant can be seen when the process of cooking water. Initially housed in the cooking water and then given the heat of the fire that burns beneath the axis. As a result of combustion raises the temperature of the water continues to increase until the limit of its boiling point. Because the burning continues, the water that is cooked beyond its boiling point until steam arises. This steam is used to turn turbines and generators that will produce electrical energy.
Cycle Power Plant
First demin water is located in a place called Hotwell.
From Hotwell, water flowing to the Condensate Pump for then pumped into the LP Heater (Low Pressure Heater) that pungsinya to warm the first stage. Location hotwell and condensate pump is located at the base of the plant floor or so-called Ground Floor. Furthermore, the water flow into the Deaerator.
In dearator water will undergo a process of release of mineral ions remaining in the water and not needed, such as Oxygen and others. Can also be said deaerator has puncture to remove bubble / balloon commonly found in surface water. In order for this release process is complete, the water temperature must meet the required temperature. Hence, during the journey to Dearator, water experienced by some process of heating device called LP Heater. Location dearator were upstairs (but not the top). As an illustration in the Muara Karang power plant unit 4, dearator located on the 5th floor of 7 floor available.
From dearator, water fall back into the Ground Floor. Arriving at Ground Floor, water is pumped directly by the Boiler Feed Pump / BFP (water pump filler) to the boiler or place, Äúmemasak, Äù water. You can imagine this like a drum boiler, but a giant-sized drums. The water being pumped is highly pressurized water, because it provided for the steam generated is also high pressure. That's why making dearator power plant construction is on the floor above and the BFP are on the ground floor. Since the launching of water from a height make the water high pressure.
Before entering the boiler to, Äúdirebus, Äù, again amended water heating process at HP Heater (High Pressure Heater). Afterwards, the water enters the boiler is located in the floor above.
In these boilers there cooking process water to produce steam. This process requires a fire which generally use coal as the basic material with the assistance of combustion air from the FD Fan (Force Draft Fan) and lubricants derived from Fuel Oil tank.
The fuel is pumped into the boiler through the Fuel Oil Pump. Power plant fuel manifold. Some use oil, oil and gas or the term dual firing and coal.
While the air produced by Force Draft Fan (FD Fan). FD Fan took the outside air to assist the combustion process in boilers. In perjalananya toward the boiler, the air temperature is increased by the water heater (air heater) for the combustion process can occur in the boiler.
Back to the water cycle. After combustion, the water began to change form into vapor. However steam combustion products has not been feasible to rotate the turbine, because it is still in the form of saturated steam or steam that still contains moisture. The water content is harmful to the turbine, because the rotation up to 3000 rpm, a drop of water able to make turbine blades become eroded.
To remove water content, the saturated vapor in the dry in the super heater so that the steam produced to steam dry. This dry steam is used to turn turbines.
When successful spin turbines spin generators will then be automated spinning, because between the turbine and generator are on one axis. This generator produces electrical energy.
In the generator there is a giant magnetic field. Turnover generator produces a potential difference in these magnets. The potential difference is the embryo of electrical energy.
Electrical energy is delivered to the transformer to change voltage and then distributed through a transmission line PLN.
Dry steam used to turn turbines will fall back to the ground floor. Steam is undergoing a process of condensation within the condenser so that eventually transformed back into the water and enter into hotwell.
Cycle Power Plant is a closed cycle (close cycle) which ideally do not need more water if the conditions are sufficient. But the reality is still needed plenty of water booster every day. This indicates a lot of leaks in water pipes and steam lines in a power plant.
To keep the cycle is still running, then to cover the shortage of water in the cycle due to leakage, hotwell always added water according to the needs of demineralized water from tanks.
Coal Power Plant Working System
1. Clean coal combustion system
The working principle is the coal power plant that will be used / worn burned in the boiler in stages. This is intended to obtain a low firing rate and without reducing the temperature required to obtain low NOx formation. Coal before burning it rolled up to resemble grains of rice, then put into a container (boiler) by spraying, in which the basic shape of the container and a perforated grill frame. Combustion can occur with the help of a blown air from the bottom up and the speed of air inflatable arranged, resulting in grain brick embers carried slightly raised slightly without forming a layer of coal grains are floating. In addition to floating point is also moving coal means it indicates the occurrence of air circulation that will give good effect so that the grain was all burned. Because the coal grains relative has the same size and the distance of adjacent consequently it became a floating layer of heat is good. Because the low temperature combustion process so that the resulting NOx levels to be low, thus this combustion system can reduce the pollutant. When inserted into the boiler furnace lime (Ca) and from the bottom of the furnace the temperature of 750-950 ¼ C air entered the floating layer is formed as a result of burns. On that layer chemical reaction occurs that causes the sulfur bound with lime to produce CaSO4 in the form of dust, so easy to fall with ash. This causes a reduction in emissions to 98% and its ash CaSO4 can be utilized. The advantage of this combustion system is able to use low-quality coal with high sulfur content coal as it is widely available in Indonesia.
2. The process of electrical energy
Burning coal will produce steam and hot exhaust gas. Exhaust gas it serves also to heat the boiler pipe above the floating layer. Flue gas then flowed to the cleaners where there is dust settling after a gas appliance is clean and then thrown into the air through the chimney. While the steam flowing to the turbine which will cause the turbine to move, but because the shaft coupled turbine / generator shaft is coupled with the result that the turbine movement or motion will cause the generator to produce electrical energy. Steam was then fed to a condenser so that turned into water and with the help of water pumps that fed water to the boiler as filler.
Generators are usually large with a total of more than one unit and operated in different ways. While medium-sized generator is designed based on the assumption that during the period of benefit will occur 10,000 times star-stop. Means for a year carried out 250 x star-stop the aging plant can reach 40 years. If the generator power increases, the speed increase as well and when the speed of criticism it is necessary to pass control shaft vibration generator so that did not happen. For the rotor and stator construction and installation of quality needs improvement. Boilernya using natural circulation and produces steam with a pressure of 196.9 kg/cm2 and a temperature of 554 ¼ C. This power plant is equipped with an electro static precipitator is a device for controlling the particle that will come out the chimney and coal ash processing equipment. Who's the steam that is used and then cooled in a condenser so that the produced water that flowed into the boiler. At the time of the coal power plant operates at a condenser temperature rising so fast, resulting in the condenser becomes hot. Moderate to cool the condenser water can be used, but must in large numbers, it is this which causes the power plant was built close to water sources much like the river or the beach.
Efficiency
When the coal power plant kondensornya pressure falls, the power point increases. Usually the condenser pressure are directly related or proportional to the amount of cooling water temperature from the steam in the condenser. So when the temperature is low, then the prisoner was also low and the lowest temperature will be generated / occurred saturated pressure. Because the cooling water is typically consists of water originating from the steam turbine and water comes from the sea and rivers. As a result, the lowest temperature in accordance with the amount of water used to pressure saturated difficult to obtain. Increased efficiency can be done by re-heating and combustion of low quality coal
1. Warming Birthdays
This can be done by dividing the turbine into two parts, high pressure (TT) and the low pressure (TR) located on a single shaft. Thus, this plant has the following composition: Boilers - TT - TR - Generator.
How it works:
Steam from the boiler input / channeled to the TT, setela h steam is used streamed back to the boiler for reheating. Then the steam from the boiler was drained back into the turbine TR to be used as an activator generator. Therefore, the amount of energy that can be utilized as a major usability or efiseinsi result of no decision. From this it can be concluded if the turbine is divided into three parts, namely TT, TM, and TR, the energy obtained is also great, this is usually used on machines with large size.
Increasing temperature (up to 560 ¼ C) and pressures (up to 250 kg/cm2 mancapai) steam power plant would lead to more rapid growth. This is indicated by the increased efficiency and reliability. With the increased power also means the design of the boiler must be repaired is equipped with NOx control equipment, equipment to remove sulfur from flue gases and equipment to prevent a variety of particles out of the chimney. Improved efficiency in coal fired power plant can also be done by increasing the length of the blade. This is because with long blades which means that loss-offs will be reduced.
2. Floating Layer Combustion Pressure
Combustion process using pressurized air or compressed means of heat transfer is increased as a result of steam and exhaust gas temperature also increases. This hot exhaust gas after cleaning can be used to drive gas turbines coupled with generators to produce electrical energy. So the electrical energy in the combustion process is produced by steam and exhaust gas, it is this which causes the combustion efficiency of this increase. Apart from the gas turbine also produces enough hot exhaust gas that can be used to heat water coming out of the steam turbine condenser is then fed into the boiler is gas that has cooled in the exhaust into the air through the chimney. By using a floating layer of pressurized combustion, then the low-quality coal that can be used to become an environmentally friendly electrical energy. q
