Energy conversion process of thermal power station

Waste heat

Nuclear reactors need to be cooled, typically with water (sometimes not directly). Using water to take energy away from a heat source requires a cold source, a process called the Rankine cycle. There is a limit to how much heat can be converted into energy through the Rankine cycle. The excess heat needs to be discharged as waste heat, which requires cooling water. Rivers are the most commonly used source of cooling water and also the site of waste heat discharge. The temperature of the waste water must be limited, otherwise it will kill the fish in the river. Hot water that is warmer than normal in the biosphere is a potential long-term hazard. In most new nuclear plants, this problem is solved by cooling towers. Wastewater is a problem for all conventional power plants, including coal, oil and gas power plants, because they rely on the Rankine cycle to generate energy. The four power plants differ only in their heat sources.

The need to limit exhaust gas temperatures will also limit power generation capacity. In extremely hot weather, when electricity use is highest, a nuclear power plant's output can drop because the cooling water in the plant becomes hotter, making it less efficient. Engineers take this into account when improving the design of a nuclear power plant, because increased cooling capacity means more money to build.

Hydropower is the use of water potential and kinetic energy into electricity to generate electricity. Hydropower plants are called hydroelectric power plants, referred to as hydropower plants, also known as hydropower stations.

The drop of water forms kinetic energy under the action of gravity, and the water is diverted from the high water source such as a river or reservoir to the low place. The pressure or flow rate of water is used to impact the turbine and make it rotate, thus converting the water energy into mechanical energy, and then the turbine drives the generator to rotate and cut the magnetic field line to produce alternating current.

Favorable aspect

Clean: Water can be a renewable energy source, basically pollution-free.

Low operating cost, high efficiency;

Power supply on demand;

Inexhaustible, inexhaustible, renewable

Flood control

Provision of irrigation water

Improve river navigation

The project will also improve the transportation, power supply and economy of the area, especially the development of tourism and aquaculture. The Tennessee River Comprehensive Development Program in the United States was the first large-scale water project to drive overall economic development.

downside

Ecological damage: increased erosion of the water flow below the dam, changes in the river and the impact on flora and fauna. However, these negative effects are predictable and mitigated. Such as reservoir effect

It is necessary to build DAMS and immigrants, and the infrastructure investment is large

In areas with large variations in precipitation seasons, electricity generation is low or even stopped during the rainy season

There is less fertile alluvial soil downstream

The working principle of nuclear power plant: Nuclear power plant is the use of nuclear fission reaction released energy, energy conversion and electricity generation.

Energy conversion situation:

1, the first way: this process is the conversion of nuclear fission energy to 1, the first way: this process is the energy conversion process of nuclear fission energy into heat energy.

2, the second circuit: this process is called the energy conversion process of heat energy into mechanical energy.

A nuclear power plant is a facility that converts nuclear energy into electricity through appropriate equipment. Nuclear power plants use nuclear reactors to replace the boilers of thermal power plants, and the special form of "combustion" of nuclear fuel in the nuclear reactor generates heat, so that nuclear energy is converted into heat energy to heat water and produce steam.

The system and equipment of a nuclear power plant are usually composed of two major parts: the nuclear system and equipment, also known as the nuclear island; Conventional systems and equipment, also known as conventional island

Nuclear power plant

Systems and equipment that convert nuclear energy released by nuclear fission into electrical energy are usually called nuclear power plants or atomic power stations. Nuclear power station is a kind of power station with high energy and low material consumption. Taking a power station with a power generation of 1 million kilowatts as an example, if coal is burned, it needs to consume about 7,000 to 8,000 tons of coal every day, and it needs to consume more than 2 million tons a year. If a nuclear power plant is used, it only consumes 1.5 tons of fissile uranium or plutonium per year, and a refueling can run continuously at full power for a year. It can greatly reduce the transportation and storage problems of fuel for power stations. In addition, during the combustion of nuclear fuel in the reactor, new nuclear fuel can also be produced. Nuclear power plants have high infrastructure investment, but lower fuel costs, lower power generation costs, and reduce pollution. By the end of 1986, 397 nuclear power plants had been built in 28 countries and regions. According to the statistics of the International Atomic Energy Agency, it is expected that 58 countries and regions will build nuclear power plants in the early 21st century, and the total number of power plants will reach 1000, the installed capacity will reach 800 million kilowatts, and the nuclear power will account for 35% of the total power generation. It can be seen that in the future for a long period of time, nuclear power will become the main energy of the power industry.