The working principle of a nuclear power plant is that the energy released during the fission process of nuclear fuel is extracted by the coolant circulating in the reactor and transmitted to the boiler to generate steam to drive the turbine and drive the generator to produce electricity.
Nuclear energy, also called atomic energy, is the enormous energy released when the structure of the atomic nucleus changes, in two main forms: fission energy and energy of merger. Currently, nuclear power generation uses fission energy. Taking a pressurized water reactor nuclear power plant as an example, the nuclear fuel heats the high pressure water in the primary circuit using the heat generated by nuclear fission in the reactor, and the water in the primary circuit heats the water from the secondary circuit through the steam generator toturn put it into steam.
Steam enters the steam turbine through the pipeline, driving the turbine generator to produce electricity, and the generated electricity is sent to thousands of homes through the power grid. The energy conversion of the whole process is from nuclear energy to thermal energy, from thermal energy to mechanical energy, and from mechanical energy to electrical energy.
Nuclear power plants can be divided into two parts. One is the nuclear island, including the reactor building, auxiliary building, nuclear fuel building and emergency diesel engine building. The second is the conventional island, including the turbogenerator building and the seawater pump room. The types of reactors currently used in Chinese nuclear power plants include pressurized water reactors, heavy water reactors, pressurized water reactors, gas cooledhigh temperature and fast neutron reactors.
Types of nuclear power plants
(1) Nuclear power plant with gas-cooled reactor The reactor uses natural uranium as fuel, graphite as moderator and carbon dioxide or helium is used as a coolant. This type of reactor is large and expensive to build due to the large amount of fuel loaded into it at one time. Great Britain and France used this type of battery.
(2) Improved gas-cooled reactor type nuclear power plant. The moderator and coolant used in the reactor are the same as those in the gas-cooled reactor type mentioned above. the fuel uses 2.5-3% low enriched uranium, so it is installed in one go. The incoming fuel represents only 1/5 to 1/4 (by mass) of natural uranium, the volume of the reactor is therefore considerable.slightly reduced.
It is also easier to replace fuel, and it can operate at higher temperatures and has higher thermal efficiency. The United States and Germany have adopted this type of battery. The gas-cooled reactor at China's Shidaowan nuclear power plant also adopts this solution.
(3) Light water reactor nuclear power plant. The reactor uses 2% to 3% low-enriched uranium as fuel and water as a moderator and coolant. This type of reactor is small, inexpensive and the technology is easier to master. More than 85% of the world's nuclear power plants use this type of reactor, and the vast majority of China uses this type of reactor.
Reference for the above content: Baidu Encyclopedia-Nuclear Power Plant