Thermal power generation. In this case, the electrical energy is converted to thermal energy of the combustion of fossil fuels (coal, gas, oil, peat, oil shale), the main usage is in industry and utilities. The principle of operation of thermal power stations is thе following: heat is selected as a result of fuel burning in the special combustion chamber. The heat turns water into steam in a special conduit system arranged in the boiler. Vapor pressure rotates a rotor of the turbine transferring energy of rotation to a shaft of the generator, which generates electric current. Thereafter, the steam is condensed and becomes water again, which is returned to the pipe system. It is a vicious process.
The thermal power industry has thermal power plants (TPP), which are of two main types:
- Condensation thermal power plant (CTPP);
- Heating thermal power plant (combined heat and power, TPP). Combined framing of electrical and thermal energy at the same station is called heating. The principal difference between TPP and CTPP is that part of the heated steam in the boiler goes to heating needs.
- Relatively free geographical location, associated with widespread fuel resources;
- The ability to generate electricity without seasonal fluctuations of power;
- As a rule the areas of alienation and withdrawal from economic circulation of land for construction and operation are less than the following is needed for nuclear power plants and hydroelectric power plants.
However, the TPP has a direct and severe adverse impact on the environment and is the most "dirty" sources of energy. Plants working on coal bring the greatest damage to the environment surrounding regions, among the most environmentally "clean" there is TPP using natural gas in its process.
Placing of generating capacities of power industry depends on two main factors: the resource and the consumer. Before the advent of power lines electric power industry focused primarily on consumers, using imported fuel. Now, after the construction of networks of high voltage transmission lines and creating of the Unified Energy System of Russia (UES) bigger attention is paid to a resource factor in case of placing of power stations.
In Russia, they began to create power plants in the late XIX and early XX centuries, however, the rapid growth of thermal power was in the 20-ies of XX century. The first thermal power plant was built in the USSR in 1922 and was called "Utkin creek". Power station №3, which was converted to the combined production of heat and electricity, is the first combined heat-and-power plant in Russia.
Technical assistance to foreign countries in the construction of thermal power plants were in the late 50- ies of the last century. Since 1956 there have been put into operation thermal power plants in such countries as Bulgaria, Hungary, Poland, Greece, Vietnam, China, Mongolia, Iran, Iraq. The range of input capacity is of 8 MW to 5200 MW; such thermal power plants have been constructed on the basis of the traditional and combined cycle, using all types of fuel (coal, brown coal, lignite, fuel oil, diesel fuel).
Currently, there were introduced new environmental safety standards for thermal power plants, which claim that all plants should be compulsory equipped by multistage systems of trapping and utilization of harmful dust and gas bursts (filters, catalyst stages), and also plants of essentially new types were widely adopted:
- Gas turbine plants (GTP), where instead of steam turbines there are gas turbines on liquid or gaseous fuels;
- Gas and steam turbine plants (GSTP), where waste heat is used for heating water to produce low-pressure steam in steam generators;
- Magnetohydrodynamic generators ( MHDG ) for direct conversion of thermal energy into electrical energy.