CHP: decoding. Cogeneration plants (CHP)

Supplying the population with heat and electricity is one of the main tasks of the state. In addition, without generating electricity, it is impossible to imagine a developed manufacturing and processing industry, without which the country's economy can not exist in principle.

One of the ways to solve the energy shortage is to build a CHP plant. The interpretation of this term is quite simple: it is the so-called thermal power plant, which is one of the most common types of thermal power plants. In our country, they are very common, because they work on organic fossil fuels (coal), to the characteristics of which they make very modest demands.

Features

That's what a CHP plant is. Deciphering the concept you already know. But what are the specific features of this type of power plant? After all, it is no coincidence that they are singled out in a separate category !?

The fact is that they produce not only electricity, but also heat, which is supplied to consumers in the form of hot water and steam. It should be noted that electricity is a by-product, since steam, which is supplied to heating systems, first rotates the turbines of the generators. Combination of two enterprises (boiler and power plants) is good because it is possible to significantly reduce fuel consumption.

However, this also leads to a rather insignificant "distribution area" of the thermal power station. The decoding is simple: since not only electricity is supplied from the station, which can be transported to thousands of kilometers with minimal losses, but also a heated coolant, they can not be located at a significant distance from the settlement. Not surprisingly, almost all CHP plants are built in close proximity to the cities where they heat and light the inhabitants.

Ecological significance

Thanks to the fact that in the construction of such a power plant it is possible to get rid of many old city boiler houses that play an extremely negative role in the ecological state of the district (a huge amount of soot), the city's air purity can sometimes be increased by an order of magnitude. In addition, new CHP plants allow the elimination of garbage debris in urban landfills.

The newest cleaning equipment makes it possible to effectively purge the emission, and the energy efficiency of such a solution is extremely high. Thus, the release of energy from burning a ton of oil is identical to the volume that is released when recycling two tons of plastic. And this "good" is enough for tens of years to come!

Most often, the construction of a combined heat and power plant involves the use of fossil fuels, as we mentioned above. However, in recent years it is planned to create nuclear power plants, which will be installed in the hard-to-reach regions of the Far North. Since fuel delivery there is extremely difficult, nuclear power is the only reliable and constant source of energy.

What are they like?

There are CHP (photo of which is in the article) industrial and "household", heating. As it is easy to guess from the name, industrial power plants provide electricity and heat to large industrial enterprises.

Often, they are being built at the stage of erecting the plant, forming together with it a single infrastructure. Accordingly, "household" varieties are erected near the sleeping microdistricts of the city. In industrial CHP, heat is transferred in the form of hot steam (no more than 4-5 km), in the case of heating - using hot water (20-30 km).

Information about the equipment of stations

The main equipment of these enterprises are turbine units that transfer mechanical energy into electricity, and boilers responsible for producing steam that rotates the flywheels of generators. The turbine unit includes both a turbine and a synchronous generator. Tubes with a back pressure of 0.7-1.5 MN / m2 are put on those CHPPs that supply heat and power to industrial facilities. Models with a pressure of 0.05-0.25 MN / m2 serve to provide household consumers.

Efficiency issues

In principle, all the heat produced can be used completely. That's just the amount of electricity that is generated at the CHP (the decoding of this term you already know), directly depends on the heat load. Simply put, in the spring-summer period, its output is reduced almost to zero. Thus, back-pressure installations are used only to supply industrial capacity, where the consumption value is more or less uniform throughout the period.

Condensing type plants

In this case only so-called "steam of selection" is used for supplying consumers with heat, and all other heat is often simply lost, dissipated in the environment. To reduce energy losses, such CHP should operate with minimal heat output to the condensing unit.

However, since the times of the USSR such stations have been built in which the hybrid regime is constructively provided: they can operate as conventional condensing thermal power plants, but their turbine generator is quite capable of operating in back pressure mode.

Universal varieties

Not surprisingly, it is the steam condensation plants that have been maximized due to their versatility. So, only they enable practically independently to regulate electric and thermal load. Even if the heat load is not expected at all (in the case of a particularly hot summer), the population will be supplied with electricity according to the previous schedule (Western CHP in St. Petersburg).

"Thermal" types of CHPP

As you could already understand, the generation of heat at such power stations is characterized by extreme unevenness throughout the year. Ideally, about 50% of hot water or steam is used to heat consumers, and the rest of the heat transfer medium is used to generate electricity. This is how the South-Western TPP works in the Northern capital.

Heat release in most cases is carried out by two schemes. If an open version is used, hot steam from turbines goes directly to consumers. In the event that a closed circuit was selected, the coolant is supplied after passing the heat exchangers. The choice of the scheme is determined on the basis of many factors. First of all, the distance from the object provided by heat and electricity, the amount of population and season is taken into account. So, the South-Western TPP in St. Petersburg operates in a closed system, as it provides greater efficiency.

Characteristics of the fuel used

Solid, liquid and gaseous fuels can be used. Since CHP plants are often built in close proximity to large settlements and cities, it is often necessary to use its valuable types, gas and fuel oil. The use of coal and garbage as such in our country is rather limited, since not all stations have modern efficient air-cleaning equipment.

To clean the exhaust of the plants, special particulate trappers are used. In order to dissipate solid particles in sufficiently high layers of the atmosphere, pipes are built at a height of 200-250 meters. As a rule, all cogeneration plants (CHP) stand at a sufficiently large distance from water supply sources (rivers and reservoirs). Therefore, artificial systems are used, which include cooling towers. Direct water supply is extremely rare, in very specific conditions.

Features of gas stations

Gas heating plants stand apart. Heat supply of consumers is realized not only due to the energy that is generated when burning liquefied gas, but also with the utilization of heat of gases, which are formed in this case. The efficiency of such plants is extremely high. In some cases, nuclear power plants can also be used as thermal power plants. This is especially common in some Arab countries.

There, these stations play two roles at once: they supply the population with electricity and industrial water, as they simultaneously serve as desalters for sea water. And now we will consider the main thermal power stations of our country and near abroad.

South-West, St. Petersburg

In our country, Western Thermal Power Plant, which is located in St. Petersburg, is famous. It is registered as OJSC "Yugo-Zapadnaya CHPP". The construction of this modern facility pursued several functions at once:

• Compensation of a strong deficit of thermal energy, which hampered the intensification of the housing construction program.
• Increasing the reliability and energy efficiency of the city system as a whole, since St. Petersburg was the problem with this aspect. The CHP allowed us to partially solve this problem.

But this station is also known for being one of the first in Russia to comply with the strictest environmental requirements. For the new enterprise, the city government allocated an area of more than 20 hectares. The fact is that the reserve area was reserved for the construction, remaining from the Kirov district. In those parts there was an old collection of ash from CHPP-14, and therefore the district was not suitable for housing construction, but extremely well located.

The launch took place at the end of 2010, and almost all the city's leadership attended the ceremony. Two new automatic boiler plants were commissioned .

Murmansk

The city of Murmansk is known as the base of our fleet on the Baltic Sea. But it is also characterized by extreme severity of climatic conditions, which imposes certain demands on its energy system. Not surprisingly, Murmansk CHP is in many respects a completely unique technical facility, even in the whole country.

It was put into operation as far back as 1934, and since then it continues to regularly supply heat and electricity to the city's residents. However, in the first five years Murmansk CHP was a conventional power plant. The first 1150 meters of the heating main were laid only in 1939. The case in the neglected Nizhne-Tulomskaya HPP, which almost completely blocked the city's electricity needs, and therefore it became possible to release part of the heat output for heating the city's houses.

The station is characterized by the fact that the whole year it works in a balanced mode, since its thermal and energy output is approximately equal. However, in the conditions of the polar night, the CHP plant, at some peak moments, starts using most of the fuel just for electricity generation.

Novopolotsk station, Belarus

The design and construction of this facility began in August 1957. The new Novopolotsk CHPP was supposed to solve the problem of not only the heat supply of the city, but also the provision of electricity to the oil refinery that was being built in the same area. In March 1958 the project was finally signed, approved and approved.

The first stage was put into operation in 1966. The second was launched in 1977. At the same time Novopolotskaya CHPP was modernized for the first time, its peak capacity was increased to 505 MW, and a little later laid the third stage of construction, completed in 1982. In 1994 the station was transferred to liquefied natural gas.

To date, about 50 million US dollars have already been invested in the modernization of the enterprise. Thanks to such impressive cash injections, the company was not only fully transferred to gas, but also received a huge amount of completely new equipment, which will allow the station to serve for decades.

conclusions

Oddly enough, to date, it is the obsolete CHP plants that are truly universal and promising stations. Using modern neutralizers and filters, it is possible to heat water by burning almost all the garbage that produces a settlement. In this case, a triple benefit is achieved:

• Landfill is unloaded and cleared.
• The city receives cheap electricity.
• The problem with heating is being solved.

In addition, in the coastal areas it is quite feasible to build a CHP plant, which will simultaneously be a desalination plant for sea water. Such a liquid is quite suitable for irrigation, for livestock complexes and industrial enterprises. In a word, the real technology of the future!