Senin, 08 Juli 2013

power plants

NPP basically operates on the same principle as conventional power plants, but the differences in the way the generation of heat to generate steam. In the conventional power plants, the heat generated from the combustion of fossil (oil, coal, gas), while the heat generated from nuclear fission reactions of atomic nuclei fuel (Uranium) in a nuclear reactor. The resulting heat is used to generate steam in the steam generators and then, just as in a conventional power plant, the steam is used to drive a turbine and generator to produce electricity. In electricity generation, nuclear power does not release fumes or dust containing heavy metals or CO2, SO2, NOx into the environment.

 The figure below shows the operation principle of the scheme NPP press type reactor (PWR).

As mentioned above, the heat to generate steam in a nuclear core obtained from the division process. The figure below shows the core division process. When a neutron particle successful entry into the nucleus of uranium fuel, the uranium core becomes unstable and consequently have cleavage. The results of this division are two other pieces of material atoms, 2 to 3 pieces of new neutrons and energy. Total mass of all the materials that formed after the fission of uranium nuclei is smaller than before the division. The difference is that the mass turned into energy. Newly formed neutron core after division can grind other uranium nuclei and so generate other material atoms, 2-3 pieces of new neutrons and energy. And so on, forming a chain reaction. One gram of Uranium will be able to generate power equal to 1 million watts for 1 day. If a home uses energy of 1000 kilowatt-hours in a day, the energy produced 1 gram of uranium can be used for about 24 days.

In order for a chain reaction does not develop into uncontrollable, like the atom bomb, the control material is used, among others, made out of cadmium, to create a chain reaction running stable and controllable. New neutron fission results have a very high speed, therefore in order to more easily fit into the nucleus of neutrons must be slowed. Materials often used as pelambat or moderator is plain water that has minerals removed. Can also use heavy water, or graphite as a moderator in accordance with the type of fuel. The heat generated in the uranium fuel is very high. If the cooling is not done then the fuel could be damaged or melted. There are several types of materials that are usually used as a coolant, such as light water, heavy water, liquid sodium metal, and gas. Selection of type of coolant depends also on the type of fuel. Fulfillment Energy Indoneseia that once rich with energy resources, is now no longer the case. Indonesian petroleum resources of around 321 billion barrels (1.2 percent of the world's potential), about 507 TSCF gas (3.3 percent of the world's potential), coal about 50 billion tonnes (3 per cent of the world's potential), approximately 27,000 MW of geothermal (40 percent of the potential of the world), and about 75,000 MW hydropower (0.02 per cent of the world's potential). Proved reserves of crude oil in 2002, about 5 billion barrels, proven natural gas reserves around 90 TSCF, and proven coal reserves of about 5 billion tons. With a production level as in 2002, and in the absence of new proven reserves, oil reserves will be exhausted within 10 years, 30 years of natural gas, and coal 50 years. Minister of Energy and Mineral Resources (ESDM) in the First Congress of Accounting Professional Organization Practitioner of Natural Resources and Environment in Baturaden, December 12, we estimate the oil reserves can only provide for up to seven years. How do we meet the energy needs of the future.
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Diesel engine driving

Diesel engine driving a generator that is widely used in the field, generally single-cylinder diesel engine water-cooled horizontal. Cooling water circulation system uses natural circulation or the cooling water circulation pump does not use circulators (water pump). Circulation of this kind took place because of the differences in specific gravity due to propagation of the cooling water heat received from the cylinder block. The cooling water circulation can be understood by considering the illustration above water heated furnace, the following:

High water temperature (heat) has a lower specific gravity and tend to move to the top (surface). Instead of water where the temperature is lower (cooler) its density will be higher and tend to move down (around the block cylinder). The advantage of this type does not require a circulation pump circulators so much simpler construction.
Broadly speaking, the amount of water in the cooling system can be divided into 3 types / construction, include: (a). Hopper type, (b). Radiator type and (c). Condenser type.
Diesel engine cooling system type hopper, the cooling effect is obtained with the cylinder block merambatkan heat to the cooling water, so the water will evaporate into the surface. Within a certain period of operation (40 minutes to 1 hour) of cooling water in the tank should be added. Indicator of the amount of cooling water hopper type typically use floating balls. If the ball is not visible apungnya, means the amount of cooling water has been depleted and need to be added. Diesel engine with radiator type cooling system, usually equipped with a cooling fan (cooling fan) and close the radiator. When the engine is operating, the water was around the block cylinder gets hot and moving up to the top of the tank by passing through the fins (fin) radiator. Obtained from the cooling effect of air flow from the cooling fan to the fins (fin) radiator. Radiator cap serves to increase the air pressure in the tank resulting in cooling water boiling point will be higher than 1000C, so it can slow down the process of evaporation. The advantage compared to the type of hopper is the frequency of addition of cooling water into the lower tank. Diesel motor with the type of condenser cooling system is also equipped with a cooling fan (cooling fan), but part of it is not closed (no radiator cap). Cooling effects utilizing the principle of condensation (condensation). Cooling water vapor is passed to the small pipes that fed air from the cooling fan, so it will condense and become water again. The water will be collected in the condenser tank. When the amount of cooling water in the tank bottom (above the cylinder block) is reduced, the air pressure will drop (happened kevacuman). This caused the water in the condenser tank is sucked down into the tank (in the block). Advantages type radiator and cooling system condenser type is compared with hopper type machine can be operated for about 10 hours continuously without adding cooling water into the tank.
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