Once, when we were driving into the glorious city of Cheboksary, from the east, my wife noticed two huge towers standing along the highway. "And what is it?" - she asked. Since I absolutely did not want to show my wife my ignorance, I dug a little into my memory and came out victoriously: “These are cooling towers, don’t you know?” She was a little confused: “What are they for?” “Well, there’s something there to cool, it seems.” "And what?". Then I became embarrassed because I didn’t know how to get out of it any further.
This question may remain forever in the memory without an answer, but miracles happen. A few months after this incident, I see a post in my friend feed about a recruitment of bloggers who want to visit the Cheboksary CHPP-2, the same one that we saw from the road. You have to suddenly change all your plans; missing such a chance would be unforgivable! So what is CHP? According to Wikipedia, CHP - short for combined heat and power plant - is a type of thermal station that produces not only electricity, but also a source of heat, in the form of steam or hot water. I’ll tell you how everything works below, but here you can see a couple of simplified diagrams of the station’s operation.

So, it all starts with water. Since water (and steam, as its derivative) at a thermal power plant is the main coolant, before it enters the boiler, it must first be prepared. In order to prevent scale from forming in boilers, at the first stage, the water must be softened, and at the second, it must be cleaned of all kinds of impurities and inclusions. All this happens on the territory of the chemical workshop, in which all these containers and vessels are located.


Water is pumped by huge pumps.
The work of the workshop is controlled from here.
There are a lot of buttons around...
Sensors...
And also completely incomprehensible elements... The quality of the water is checked in the laboratory. Everything is serious here...

The water obtained here will be called “Clean Water” in the future. So, we've sorted out the water, now we need fuel. Usually it is gas, fuel oil or coal. At the Cheboksary CHPP-2, the main type of fuel is gas supplied through the Urengoy - Pomary - Uzhgorod gas pipeline. Many stations have a fuel preparation point. Here, natural gas, like water, is purified from mechanical impurities, hydrogen sulfide and carbon dioxide. The thermal power plant is a strategic facility, operating 24 hours a day and 365 days a year. Therefore, here everywhere, and for everything, there is a reserve. Fuel is no exception. In the absence of natural gas, our station can operate on fuel oil, which is stored in huge tanks located across the road.
Now we have Clean water and prepared fuel. The next point of our journey is the boiler and turbine shop. It consists of two sections. The first contains boilers. No not like this. The first contains BOILERS. To write differently, a hand doesn’t rise, each one is the size of a twelve-story building. There are five of them at CHPP-2 in total.
This is the heart of the power plant and where most of the action takes place. The gas entering the boiler burns, releasing a crazy amount of energy. “Clean water” is also supplied here. After heating, it turns into steam, more precisely into superheated steam, having an outlet temperature of 560 degrees and a pressure of 140 atmospheres. We will also call it “Clean Steam”, because it is formed from prepared water. In addition to steam, we also have exhaust at the exit. At maximum power, all five boilers consume almost 60 cubic meters of natural gas per second! To remove combustion products, you need a non-childish “smoke” pipe. And there is one like this too.

The pipe can be seen from almost any area of ​​the city, given the height of 250 meters. I suspect that this is the tallest building in Cheboksary. Nearby there is a slightly smaller pipe. Reserve again. If the thermal power plant operates on coal, additional exhaust cleaning is necessary. But in our case this is not required, since natural gas is used as fuel. The second section of the boiler-turbine shop contains installations that generate electricity.
There are four of them installed in the turbine hall of the Cheboksary CHPP-2, with a total capacity of 460 MW (megawatt). This is where superheated steam from the boiler room is supplied. It is directed under enormous pressure onto the turbine blades, causing the thirty-ton rotor to rotate at a speed of 3000 rpm.
The installation consists of two parts: the turbine itself, and a generator that generates electricity.

And this is what the turbine rotor looks like.
Sensors and pressure gauges are everywhere.

Both turbines and boilers can be stopped instantly in case of an emergency. For this purpose, there are special valves that can shut off the supply of steam or fuel in a fraction of a second.
I wonder if there is such a thing as an industrial landscape, or an industrial portrait? There is beauty here.
There is terrible noise in the room, and in order to hear your neighbor you have to strain your ears. Plus it's very hot. I want to take off my helmet and strip down to my T-shirt, but I can’t do that. For safety reasons, short-sleeved clothing is prohibited at the thermal power plant; there are too many hot pipes. Most of the time the workshop is empty; people appear here once every two hours, during their rounds. And the operation of the equipment is controlled from the Main Control Panel (Group Control Panels for Boilers and Turbines). This is what the duty officer's workplace looks like.
There are hundreds of buttons around.

And dozens of sensors.
Some are mechanical, some are electronic. This is our excursion, and people are working.
In total, after the boiler-turbine shop, at the output we have electricity and steam that has partially cooled and lost some of its pressure. Electricity seems to be easier. The output voltage from different generators can be from 10 to 18 kV (kilovolts). With the help of block transformers, it increases to 110 kV, and then electricity can be transmitted over long distances using power lines (power lines).
It is not profitable to release the remaining “Pure Steam” to the side. Since it is formed from “Clean Water”, the production of which is a rather complex and costly process, it is more expedient to cool it and return it back to the boiler. And so on in a vicious circle. But with its help and with the help of heat exchangers, you can heat water or produce secondary steam, which you can safely sell to third-party consumers.
In general, this is how you and I get heat and electricity into our homes, having the usual comfort and coziness. Oh yes. But why are cooling towers needed anyway?
It turns out that everything is very simple. To cool the remaining “Clean Steam” before feeding it into the boiler again, the same heat exchangers are used. It is cooled using technical water; at CHPP-2 it is taken directly from the Volga. It does not require any special preparation and can also be reused. After passing through the heat exchanger, the water turns into steam, which cools in the cooling towers, condenses, and turns back into water. Water leaves the cooling towers through a special channel, after which, with the help of a pumping station, it is sent for reuse. In short, cooling towers are needed to cool steam, which cools other steam. Sorry for the tautology...
All operation of the thermal power plant is controlled from the main control panel.
There is always a duty officer here.
All events are logged.
Don't feed me bread, let me take a picture of the buttons and sensors...


That's almost all. Finally, there are a few photos of the station left. This is an old pipe that is no longer working. Most likely it will be demolished soon. There is a lot of agitation at the enterprise.

They are proud of their employees here.
And their achievements.
It seems that it was not in vain...
Without exaggeration, they are true professionals in their field.

The impeller blades of this steam turbine are clearly visible.

A thermal power plant (CHP) uses the energy released by burning fossil fuels - coal, oil and natural gas - to convert water into high-pressure steam. This steam, having a pressure of about 240 kilograms per square centimeter and a temperature of 524°C (1000°F), drives the turbine. The turbine spins a giant magnet inside a generator, which produces electricity.

Modern thermal power plants convert about 40 percent of the heat released during fuel combustion into electricity, the rest is discharged into the environment. In Europe, many thermal power plants use waste heat to heat nearby homes and businesses. Combined heat and power generation increases the energy output of the power plant by up to 80 percent.

Steam turbine plant with electric generator

A typical steam turbine contains two sets of blades. High-pressure steam coming directly from the boiler enters the flow path of the turbine and rotates the impellers with the first group of blades. The steam is then heated in the superheater and again enters the turbine flow path to rotate impellers with a second group of blades, which operate at a lower steam pressure.

Sectional view

A typical thermal power plant (CHP) generator is driven directly by a steam turbine, which rotates at 3,000 revolutions per minute. In generators of this type, the magnet, also called the rotor, rotates, but the windings (stator) are stationary. The cooling system prevents the generator from overheating.

Power generation using steam

At a thermal power plant, fuel burns in a boiler, producing a high-temperature flame. The water passes through the tubes through the flame, is heated and turns into high-pressure steam. The steam spins a turbine, producing mechanical energy, which a generator converts into electricity. After leaving the turbine, the steam enters the condenser, where it washes the tubes with cold running water, and as a result turns into a liquid again.

Oil, coal or gas boiler

Inside the boiler

The boiler is filled with intricately curved tubes through which heated water passes. The complex configuration of the tubes allows you to significantly increase the amount of heat transferred to the water and thereby produce much more steam.

Thermal power plants can be equipped with steam and gas turbines, with internal combustion engines. The most common are thermal stations with steam turbines, which in turn are divided into: condensing (KES)— all the steam in which, with the exception of small selections for heating feedwater, is used to rotate the turbine and generate electrical energy; heating power plants- combined heat and power plants (CHP), which are the source of power for consumers of electrical and thermal energy and are located in the area of ​​their consumption.

Condensing power plants

Condensing power plants are often called state district power plants (GRES). IES are mainly located near fuel extraction areas or reservoirs used for cooling and condensing steam exhausted from turbines.

Characteristic features of condensing power plants

1. for the most part, there is a significant distance from consumers of electrical energy, which necessitates the need to transmit electricity mainly at voltages of 110-750 kV;
2. block principle of station construction, which provides significant technical and economic advantages, consisting in increasing operational reliability and facilitating operation, and reducing the volume of construction and installation work.
3. The mechanisms and installations that ensure the normal functioning of the station constitute its system.

IES can operate on solid (coal, peat), liquid (fuel oil, oil) fuel or gas.

Fuel supply and preparation of solid fuel consists of transporting it from warehouses to the fuel preparation system. In this system, the fuel is brought to a pulverized state for the purpose of further injecting it into the burners of the boiler furnace. To maintain the combustion process, a special fan forces air into the firebox, heated by the exhaust gases, which are sucked out of the firebox by a smoke exhauster.

Liquid fuel is supplied to the burners directly from the warehouse in a heated form by special pumps.

The preparation of gas fuel consists mainly of regulating the gas pressure before combustion. Gas from the field or storage facility is transported through a gas pipeline to the gas distribution point (GDP) of the station. Gas distribution and regulation of its parameters are carried out at the hydraulic fracturing site.

Processes in the steam-water circuit

The main steam-water circuit carries out the following processes:

1. The combustion of fuel in the firebox is accompanied by the release of heat, which heats the water flowing in the boiler pipes.
2. Water turns into steam with a pressure of 13...25 MPa at a temperature of 540..560 °C.
3. The steam produced in the boiler is supplied to the turbine, where it performs mechanical work - it rotates the turbine shaft. As a result, the generator rotor, located on a common shaft with the turbine, also rotates.
4. The steam exhausted in the turbine with a pressure of 0.003...0.005 MPa at a temperature of 120...140°C enters the condenser, where it turns into water, which is pumped into the deaerator.
5. In the deaerator, dissolved gases are removed, and primarily oxygen, which is dangerous due to its corrosive activity. The circulating water supply system ensures that the steam in the condenser is cooled with water from an external source (reservoir, river, artesian well). Cooled water, having a temperature not exceeding 25...36 °C at the outlet of the condenser, is discharged into the water supply system.

An interesting video about the operation of the thermal power plant can be viewed below:

To compensate for steam losses, make-up water, which has previously undergone chemical purification, is supplied to the main steam-water system by a pump.

It should be noted that for the normal operation of steam-water installations, especially with supercritical steam parameters, the quality of the water supplied to the boiler is important, therefore the turbine condensate is passed through a system of desalting filters. The water treatment system is designed to purify make-up and condensate water and remove dissolved gases from it.

At stations using solid fuel, combustion products in the form of slag and ash are removed from the boiler furnace by a special slag and ash removal system equipped with special pumps.

When burning gas and fuel oil, such a system is not required.

There are significant energy losses at IES. Heat losses are especially high in the condenser (up to 40..50% of the total amount of heat released in the furnace), as well as with exhaust gases (up to 10%). The efficiency of modern IES with high steam pressure and temperature parameters reaches 42%.

The electrical part of the IES represents a set of main electrical equipment (generators, ) and electrical equipment for auxiliary needs, including busbars, switching and other equipment with all connections made between them.

The station's generators are connected into blocks with step-up transformers without any devices between them.

In this regard, a generator voltage switchgear is not being built at the IES.

Switchgears for 110-750 kV, depending on the number of connections, voltage, transmitted power and the required level of reliability, are made according to standard electrical connection diagrams. Cross connections between blocks take place only in switchgears of the highest level or in the power system, as well as for fuel, water and steam.

In this regard, each power unit can be considered as a separate autonomous station.

To provide electricity for the station's own needs, taps are made from the generators of each block. Generator voltage is used to power powerful electric motors (200 kW or more), while a 380/220 V system is used to power lower-power motors and lighting installations. Electrical circuits for the station’s own needs may be different.

Another interesting video about the work of a thermal power plant from the inside:

Combined heat and power plants

Combined heat and power plants, being sources of combined generation of electrical and thermal energy, have a significantly larger CES (up to 75%). This is explained by this. that part of the steam exhausted in turbines is used for the needs of industrial production (technology), heating, and hot water supply.

This steam is either directly supplied for industrial and domestic needs or partially used to preheat water in special boilers (heaters), from which water is sent through the heating network to consumers of thermal energy.

The main difference between the technology of energy production in comparison with IES is the specificity of the steam-water circuit. Providing intermediate extraction of turbine steam, as well as in the method of energy delivery, according to which the main part of it is distributed at the generator voltage through a generator switchgear (GRU).

Communication with other power system stations is carried out at increased voltage through step-up transformers. During repairs or emergency shutdown of one generator, the missing power can be transferred from the power system through the same transformers.

To increase the reliability of the CHP operation, sectioning of busbars is provided.

Thus, in the event of an accident on the tires and subsequent repair of one of the sections, the second section remains in operation and provides power to consumers through the remaining energized lines.

According to such schemes, industrial ones are built with generators up to 60 MW, designed to power local loads within a radius of 10 km.

Large modern ones use generators with a power of up to 250 MW with a total station power of 500-2500 MW.

These are built outside the city limits and electricity is transmitted at a voltage of 35-220 kV, no GRU is provided, all generators are connected into blocks with step-up transformers. If it is necessary to provide power to a small local load near the block load, taps from the blocks are provided between the generator and the transformer. Combined station schemes are also possible, in which there is a main switchgear and several generators connected according to block diagrams.

An electrical power plant is a power plant that converts natural energy into electrical energy. The most common are thermal power plants (TPPs), which use thermal energy released by burning organic fuel (solid, liquid and gaseous).

Thermal power plants generate about 76% of the electricity produced on our planet. This is due to the presence of fossil fuels in almost all areas of our planet; the possibility of transporting organic fuel from the extraction site to a power plant located near energy consumers; technical progress at thermal power plants, ensuring the construction of thermal power plants with high power; the possibility of using waste heat from the working fluid and supplying it to consumers, in addition to electrical energy, also thermal energy (with steam or hot water), etc.

A high technical level of energy can only be ensured with a harmonious structure of generating capacities: the energy system must include nuclear power plants that generate cheap electricity, but have serious restrictions on the range and rate of load change, and thermal power plants that supply heat and electricity, the amount of which depends on the demand for energy. heat, and powerful steam turbine power units operating on heavy fuels, and mobile autonomous gas turbine units that cover short-term load peaks.

1.1 Types of electrical power plants and their features.

In Fig. 1 presents the classification of thermal power plants using fossil fuels.

Fig.1. Types of thermal power plants using fossil fuels.

Fig.2 Schematic thermal diagram of thermal power plant

1 – steam boiler; 2 – turbine; 3 – electric generator; 4 – capacitor; 5 – condensate pump; 6 – low pressure heaters; 7 – deaerator; 8 – feed pump; 9 – high pressure heaters; 10 – drainage pump.

A thermal power plant is a complex of equipment and devices that convert fuel energy into electrical and (in general) thermal energy.

Thermal power plants are characterized by great diversity and can be classified according to various criteria.

Based on their purpose and type of energy supplied, power plants are divided into regional and industrial.

District power plants are independent public power plants that serve all types of consumers in the region (industrial enterprises, transport, population, etc.). District condensing power plants, which generate mainly electricity, often retain their historical name - GRES (state district power plants). District power plants that produce electrical and thermal energy (in the form of steam or hot water) are called combined heat and power plants (CHP). As a rule, state district power plants and district thermal power plants have a capacity of more than 1 million kW.

Industrial power plants are power plants that supply thermal and electrical energy to specific production enterprises or their complex, for example a chemical production plant. Industrial power plants are part of the industrial enterprises they serve. Their capacity is determined by the needs of industrial enterprises for thermal and electrical energy and, as a rule, it is significantly less than that of district thermal power plants. Often industrial power plants operate on the general electrical network, but are not subordinate to the power system dispatcher.

Based on the type of fuel used, thermal power plants are divided into power plants running on organic fuel and nuclear fuel.

Condensing power plants operating on fossil fuels, at a time when there were no nuclear power plants (NPPs), were historically called thermal power plants (TES - thermal power plant). It is in this sense that this term will be used below, although thermal power plants, nuclear power plants, gas turbine power plants (GTPP), and combined cycle power plants (CGPP) are also thermal power plants operating on the principle of converting thermal energy into electrical energy.

Gaseous, liquid and solid fuels are used as organic fuel for thermal power plants. Most thermal power plants in Russia, especially in the European part, consume natural gas as the main fuel, and fuel oil as a backup fuel, using the latter due to its high cost only in extreme cases; Such thermal power plants are called gas-oil power plants. In many regions, mainly in the Asian part of Russia, the main fuel is thermal coal - low-calorie coal or waste from the extraction of high-calorie coal (anthracite coal - ASh). Since before combustion such coals are ground in special mills to a dusty state, such thermal power plants are called pulverized coal.

Based on the type of thermal power plants used at thermal power plants to convert thermal energy into mechanical energy of rotation of the rotors of turbine units, steam turbine, gas turbine and combined cycle power plants are distinguished.

The basis of steam turbine power plants are steam turbine units (STU), which use the most complex, most powerful and extremely advanced energy machine - a steam turbine - to convert thermal energy into mechanical energy. PTU is the main element of thermal power plants, combined heat and power plants and nuclear power plants.

STPs that have condensing turbines as a drive for electric generators and do not use the heat of exhaust steam to supply thermal energy to external consumers are called condensing power plants. STUs equipped with heating turbines and releasing the heat of exhaust steam to industrial or municipal consumers are called combined heat and power plants (CHP).

Gas turbine thermal power plants (GTPPs) are equipped with gas turbine units (GTUs) running on gaseous or, in extreme cases, liquid (diesel) fuel. Since the temperature of the gases behind the gas turbine plant is quite high, they can be used to supply thermal energy to external consumers. Such power plants are called GTU-CHP. Currently, in Russia there is one gas turbine power plant (GRES-3 named after Klasson, Elektrogorsk, Moscow region) with a capacity of 600 MW and one gas turbine cogeneration plant (in the city of Elektrostal, Moscow region).

A traditional modern gas turbine unit (GTU) is a combination of an air compressor, a combustion chamber and a gas turbine, as well as auxiliary systems that ensure its operation. The combination of a gas turbine unit and an electric generator is called a gas turbine unit.

Combined-cycle thermal power plants are equipped with combined cycle gas units (CCGs), which are a combination of gas turbines and steam turbines, which allows for high efficiency. CCGT-CHP plants can be designed as condensing plants (CCP-CHP) and with thermal energy supply (CCP-CHP). Currently, four new CCGT-CHP plants are operating in Russia (North-West CHPP of St. Petersburg, Kaliningrad, CHPP-27 of Mosenergo OJSC and Sochinskaya), and a cogeneration CCGT plant has also been built at the Tyumen CHPP. In 2007, the Ivanovo CCGT-KES was put into operation.

Modular thermal power plants consist of separate, usually of the same type, power plants - power units. In the power unit, each boiler supplies steam only to its turbine, from which it returns after condensation only to its boiler. All powerful state district power plants and thermal power plants, which have the so-called intermediate superheating of steam, are built according to the block scheme. The operation of boilers and turbines at thermal power plants with cross connections is ensured differently: all boilers of the thermal power plant supply steam to one common steam line (collector) and all steam turbines of the thermal power plant are powered from it. According to this scheme, CESs without intermediate overheating and almost all CHP plants with subcritical initial steam parameters are built.

Based on the level of initial pressure, thermal power plants of subcritical pressure, supercritical pressure (SCP) and supersupercritical parameters (SSCP) are distinguished.

The critical pressure is 22.1 MPa (225.6 at). In the Russian heat and power industry, the initial parameters are standardized: thermal power plants and combined heat and power plants are built for subcritical pressure of 8.8 and 12.8 MPa (90 and 130 atm), and for SKD - 23.5 MPa (240 atm). For technical reasons, thermal power plants with supercritical parameters are replenished with intermediate overheating and according to a block diagram. Supersupercritical parameters conventionally include pressure more than 24 MPa (up to 35 MPa) and temperature more than 5600C (up to 6200C), the use of which requires new materials and new equipment designs. Often thermal power plants or combined heat and power plants for different levels of parameters are built in several stages - in queues, the parameters of which increase with the introduction of each new queue.

The modern world requires a huge amount of energy (electrical and thermal), which is produced at power plants of various types.

Man has learned to extract energy from several sources (hydrocarbon fuel, nuclear resources, falling water, wind, etc.) However, to this day thermal and nuclear power plants, which will be discussed, remain the most popular and efficient.

What is a nuclear power plant?

A nuclear power plant (NPP) is a facility that uses the decay reaction of nuclear fuel to produce energy.

Attempts to use a controlled (that is, controlled, predictable) nuclear reaction to generate electricity were made by Soviet and American scientists simultaneously - in the 40s of the last century. In the 50s, the “peaceful atom” became a reality, and nuclear power plants began to be built in many countries around the world.

The central unit of any nuclear power plant is the nuclear installation in which the reaction occurs. When radioactive substances decay, a huge amount of heat is released. The released thermal energy is used to heat the coolant (usually water), which, in turn, heats the secondary circuit water until it turns into steam. Hot steam rotates turbines, resulting in the generation of electricity.

There is ongoing debate around the world about the feasibility of using nuclear energy to generate electricity. Supporters of nuclear power plants talk about their high productivity, the safety of the latest generation of reactors, and the fact that such power plants do not pollute the environment. Opponents argue that nuclear power plants are potentially extremely dangerous, and their operation and, especially, the disposal of spent fuel are associated with enormous costs.

What is TES?

The most traditional and widespread type of power plants in the world are thermal power plants. Thermal power plants (as this abbreviation stands for) generate electricity by burning hydrocarbon fuels - gas, coal, fuel oil.


The operation scheme of a thermal power plant is as follows: when fuel burns, a large amount of thermal energy is generated, with the help of which water is heated. The water turns into superheated steam, which is supplied to the turbogenerator. Rotating, the turbines set the parts of the electric generator in motion, generating electrical energy.

At some thermal power plants, the heat transfer phase to the coolant (water) is absent. They use gas turbine units, in which the turbine is rotated by gases obtained directly from the combustion of fuel.

A significant advantage of thermal power plants is the availability and relative cheapness of fuel. However, thermal stations also have disadvantages. This is, first of all, a threat to the environment. When fuel is burned, large amounts of harmful substances are released into the atmosphere. To make thermal power plants safer, a number of methods are used, including: fuel enrichment, installation of special filters that trap harmful compounds, the use of flue gas recirculation, etc.

What is CHP?

The very name of this object resembles the previous one, and in fact, thermal power plants, like thermal power plants, convert the thermal energy of burned fuel. But in addition to electricity, combined heat and power plants (CHP stands for) supply heat to consumers. CHP plants are especially relevant in cold climate zones, where it is necessary to provide residential buildings and industrial buildings with heat. This is why there are so many thermal power plants in Russia, where central heating and water supply to cities are traditionally used.

According to the principle of operation, thermal power plants are classified as condensing power plants, but unlike them, at thermal power plants, part of the generated thermal energy is used to produce electricity, and the other part is used to heat the coolant, which is supplied to the consumer.


CHP is more efficient compared to conventional thermal power plants, since it allows you to use the received energy to the maximum. After all, after the rotation of the electric generator, the steam remains hot, and this energy can be used for heating.

In addition to thermal power plants, there are nuclear thermal power plants, which in the future should play a leading role in the electricity and heat supply of northern cities.