Modern heat and power systems of industrial enterprises consist of three parts, the efficiency of their interaction determines the volume and efficiency of consumption of fuel and energy resources. These parts are:
sources of energy resources, i.e. enterprises producing the required types of energy resources;
systems of transport and distribution of energy resources between consumers. Most often these are heat and electrical networks; consumers of energy resources.
Each participant in the system producer-consumer of energy resources has its own equipment and is characterized by certain indicators of energy and thermodynamic efficiency. In this case, a situation often arises when the high efficiency indicators of some of the system participants are offset by others, so that the total efficiency of the heat and power system turns out to be low. The most difficult stage is the consumption of energy resources.
The level of use of fuel and energy resources in domestic industry leaves much to be desired. A survey of petrochemical industry enterprises showed that the actual consumption of energy resources exceeds the theoretically required by approximately 1.7-2.6 times, i.e. the targeted use of energy resources is about 43% of the real costs of production technologies. This situation is observed at enterprises in the chemical, rubber, food and other industries where thermal secondary resources are used insufficiently or inefficiently.
The number of VERs that do not find application in industrial heat-technological and heat-power systems of an enterprise includes mainly heat flows of liquids (t< 90 0 С) и газов (t< 150 0 С) (см. табл. 1.8).
Currently, quite effective developments are known that make it possible to use the heat of such parameters directly at an industrial facility. Due to the increase in prices for energy resources, interest in them is growing, the production of heat exchangers and recycling thermotransformers is being established, which allows us to hope for an improvement in the near future in the situation with the use of such HER in industry.
As calculations of the effectiveness of energy-saving measures show, each unit of thermal energy (1 J, 1 kcal) provides an equivalent saving of natural fuel by a factor of five. In those cases where it was possible to find the most successful solutions, the savings in natural fuel reached tenfold.
The main reason for this is the lack of intermediate stages of extraction, enrichment, transformation, and transportation of fuel energy resources to ensure the amount of saved energy resources. Capital investments in energy-saving measures turn out to be 2-3 times lower than the necessary capital investments in mining and related industries to obtain an equivalent amount of natural fuel.
Within the framework of the traditionally established approach, heat and power systems of large industrial consumers are considered in one way - as a source of energy resources of the required quality in the required quantity in accordance with the requirements of technological regulations. The operating mode of thermal power systems is subject to the conditions dictated by the consumer. This approach usually leads to miscalculations when selecting equipment and making ineffective decisions on the organization of heat technology and heat power systems, i.e. to hidden or obvious overconsumption of fuel and energy resources, which naturally affects the cost of products.
In particular, seasonality has a fairly strong impact on the overall efficiency of energy consumption of industrial enterprises. In the summer, there is usually an excess supply of thermal energy technologies and at the same time there are problems associated with the insufficient volume and quality of cooling fluids due to an increase in the temperature of the circulating water. During periods of low outdoor temperatures, on the contrary, there is an overconsumption of thermal energy associated with an increase in the share of heat losses through external fences, which is very difficult to detect.
Thus, modern heat and power systems must be developed or modernized in an organic relationship with industrial heat technology, taking into account the time schedules and operating modes of both units - consumers of energy resources, and units, which, in turn, are sources of energy resources. The main objectives of industrial heat power engineering are:
ensuring the balance of energy resources with the required parameters at any time for reliable and economical operation of individual units and the production association as a whole; optimal choice of energy carriers based on thermophysical and thermodynamic parameters;
determination of the nomenclature and operating modes of backup and storage sources of energy resources, as well as alternative consumers of energy resources during the period of their excess supply; identifying reserves for increasing the energy efficiency of production at the current level of technical development and in the distant future.
In the future, PP TPPs appear to be a complex energy-technological complex in which energy and technological flows are closely interconnected. At the same time, consumers of fuel and energy resources can be sources of secondary energy for technological installations of a given production, external consumers or recycling energy installations that generate other types of energy resources.
The specific heat consumption for the production of industrial products ranges from one to tens of gigajoules per ton of the final product, depending on the installed capacity of the equipment, the nature of the technological process, heat losses and the uniformity of the consumption schedule. At the same time, the most attractive are measures aimed at increasing the energy and economic efficiency of existing production facilities and without introducing significant changes in the operating mode of the main technological equipment. The most attractive seems to be the organization of closed heat supply systems based on recovery plants, the enterprises of which have a high share of consumption of medium and low pressure water steam and hot water.
Most enterprises are characterized by significant losses of heat supplied to the system in heat exchangers cooled by circulating water or air - in condensers, coolers, refrigerators, etc. In such conditions, it is advisable to organize centralized and group systems with an intermediate coolant in order to recover waste heat. This will make it possible to connect multiple sources and consumers within the entire enterprise or a dedicated division and provide hot water of the required parameters to industrial and sanitary consumers.
Closed heat supply systems are one of the main elements of waste-free production systems. By regenerating heat of low parameters and transforming it to the required temperature level, a significant part of the energy resources can be returned, which is usually discharged into the atmosphere directly or using recycling water supply systems.
In technological systems using steam and hot water as energy carriers, the temperature and pressure of the supplied and discharged heat in the cooling processes are the same. The amount of heat discharged may even exceed the amount of heat introduced into the system, since cooling processes are usually accompanied by a change in the state of aggregation of the substance. In such conditions, it is possible to organize recycling centralized or local heat pump systems, which make it possible to regenerate up to 70% of the heat spent in heat-consuming installations.
Such systems have become widespread in the USA, Germany, Japan and other countries, but in our country not enough attention has been paid to their creation, although theoretical developments carried out in the 30s of the last century are known. Currently, the situation is changing and heat pump units are beginning to be introduced into heat supply systems of both housing and communal services and industrial facilities.
One of the effective solutions is the organization of recycling refrigeration systems based on absorption heat transformers (ATTs). Industrial refrigeration systems are based on vapor-compression refrigeration units, and the electricity consumption for cold production reaches 15-20% of its total consumption throughout the entire enterprise. Heat absorption transformers as alternative sources of cooling supply have some advantages, in particular:
to drive the ATT, low-grade heat of process water, flue gases or low-pressure exhaust steam can be used;
with the same composition of equipment, ATT is capable of operating both in refrigeration supply mode and in heat pump mode for heat supply.
The air and cold supply systems of an industrial enterprise do not have a significant impact on the supply of renewable energy sources and can be considered as heat consumers when developing utilization measures.
In the future, we should expect the emergence of fundamentally new waste-free industrial technologies created on the basis of closed production cycles, as well as a significant increase in the share of electricity in the structure of energy consumption.
The growth in electricity consumption in industry will be associated, first of all, with the development of cheap energy sources - fast neutron reactors, thermonuclear reactors, etc.
At the same time, we should expect a worsening of the environmental situation associated with the global overheating of the planet due to the intensification of “thermal pollution” - an increase in thermal emissions into the atmosphere.
Test questions and assignments for topic 1
1. What types of energy carriers are used to carry out the main technological processes in the pyrolysis department, as well as at the stage of isolation and separation of reaction products in the production of ethylene?
2. Characterize the input and output parts of the energy balance of a pyrolysis furnace. How did the organization of heating feedwater affect them?
3. Characterize the structure of energy consumption in the production of isoprene by two-stage dehydrogenation. What share of it is the consumption of cold and recycled water?
4. Analyze the structure of the heat balance for the production of synthetic ethyl alcohol by the method of direct hydration of ethylene. List the items on the expenditure side of the balance sheet that relate to thermal energy losses.
5. Explain why TAC-based heat technology is classified as low-temperature.
6. What characteristics allow us to assess the uniformity of heat loads throughout the year?
7. Give examples of industrial technologies that belong to the second group in terms of the share of heat consumption for their own needs.
8. Using the daily schedule of steam consumption at a petrochemical plant, determine its maximum and minimum values and compare them. Describe the monthly heat consumption schedule of a petrochemical enterprise.
9. What explains the unevenness of the annual heat load schedules of industrial enterprises?
10. Compare the annual load graphs of mechanical engineering enterprises and chemical plants and formulate conclusions.
11. Should combustible industrial waste always be considered secondary energy resources?
12. Characterize the structure of heat consumption in industry, taking into account the temperature level of heat perception.
13. Explain the principle of determining the available amount of heat from combustion products sent to waste heat boilers.
14. What equivalent savings of natural fuel does the saving of a unit of heat provide at the consumption stage and why?
15. Compare the yield volumes of VER in the production of butadiene using the two-stage dehydrogenation method n-butane and the method of contact decomposition of alcohol (see Table A.1.1).
Table P.l.l
Secondary energy resources of petrochemical industry production
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The presentation is additional material to lessons on energy development. The energy sector of any country is the basis for the development of productive forces and the creation of the material and technical base of society. The presentation reflects the problems and prospects of all types of energy, promising (new) types of energy, uses the experience of museum pedagogy, independent research work of students (work with the magazine “Japan Today”), and creative works of students (posters). The presentation can be used in geography lessons in grades 9 and 10, in extracurricular activities (elective classes, elective courses), during Geography Week “April 22 – Earth Day”, in ecology and biology lessons “Global problems of humanity. Raw materials and energy problem.”
In my work, I used the method of problem-based learning, which consisted of creating problem situations for students and resolving them in the process of joint activity between students and the teacher. At the same time, maximum independence of students was taken into account and under the general guidance of a teacher directing the activities of students.
Problem-based learning allows not only to form in students the necessary system of knowledge, skills and abilities, to achieve a high level of development of schoolchildren, but, most importantly, it allows the formation of a special style of mental activity, research activity and independence of students. When working with this presentation, students become aware of a current direction - the research activities of schoolchildren.
The industry unites a group of industries engaged in the extraction and transportation of fuel, generation of energy and transmission of it to the consumer.
Natural resources that are used to produce energy are fuel resources, hydro resources, nuclear energy, as well as alternative types of energy. The location of most industries depends on the development of electricity. Our country has huge reserves of fuel and energy resources. Russia was, is and will be one of the leading energy powers in the world. And this is not only because the country’s depths contain 12% of the world’s coal reserves, 13% of the world’s oil and 36% of the world’s natural gas reserves, which are sufficient to fully meet its own needs and for export to neighboring countries. Russia has become one of the world's leading energy powers, primarily due to the creation of a unique production, scientific, technical and personnel potential of the fuel and energy complex.
Raw material problem
Mineral resources– the primary source, the initial basis of human civilization in almost all phases of its development:
– Fuel minerals;
– Ore minerals;
– Non-metallic minerals.
Modern rates of energy consumption are growing exponentially. Even if we take into account that the growth rate of electricity consumption will decrease somewhat due to the improvement of energy-saving technologies, the reserves of electrical raw materials will last for a maximum of 100 years. However, the situation is further aggravated by the discrepancy between the structure of reserves and consumption of organic raw materials. Thus, 80% of fossil fuel reserves come from coal and only 20% from oil and gas, while 8/10 of modern energy consumption comes from oil and gas.
Consequently, the time frame is further narrowed. However, only today humanity is getting rid of ideological ideas that they are practically endless. Mineral resources are limited and virtually irreplaceable.
Energy problem.
Today, the world's energy sector is based on energy sources:
– Combustible mineral resources;
– Combustible organic fossils;
– River energy. Non-traditional types of energy;
– Energy of the atom.
At the current rate of increase in the price of the Earth's fuel resources, the problem of using renewable energy sources is becoming increasingly urgent and characterizes the energy and economic independence of the state.
Advantages and disadvantages of thermal power plants.
Advantages of TPP:
1. The cost of electricity at hydroelectric power stations is very low;
2. Hydroelectric power station generators can be turned on and off quite quickly depending on energy consumption;
3. No air pollution.
Disadvantages of TPP:
1. Construction of hydroelectric power stations can be longer and more expensive than other energy sources;
2. Reservoirs can occupy large areas;
3. Dams can harm fisheries by blocking access to spawning grounds.
Advantages and disadvantages of hydroelectric power stations.
Advantages of hydroelectric power stations:
– They are built quickly and cheaply;
– Operate in constant mode;
– Located almost everywhere;
– The predominance of thermal power plants in the energy sector of the Russian Federation.
Disadvantages of hydroelectric power plants:
– Consume a large amount of fuel;
– Requires a long stop during repairs;
– A lot of heat is lost in the atmosphere, a lot of solid and harmful gases are released into the atmosphere;
– Largest environmental polluters.
In the structure of electricity generation in the world, the first place belongs to thermal power plants (TPPs) - their share is 62%.
An alternative to fossil fuels and a renewable source of energy is hydropower. Hydroelectric power station (HPP)- a power plant that uses the energy of water flow as an energy source. Hydroelectric power plants are usually built on rivers by constructing dams and reservoirs. Hydropower is the production of electricity through the use of renewable river, tidal, and geothermal water resources. This use of renewable water resources involves managing floods, strengthening river beds, transferring water resources to areas suffering from drought, and preserving groundwater flows.
However, here too the energy source is quite limited. This is due to the fact that large rivers, as a rule, are very far from industrial centers or their capacity is almost completely used. Thus, hydropower, which currently provides about 10% of the world's energy production, will not be able to significantly increase this figure.
Problems and prospects of nuclear power plants
In Russia, the share of nuclear energy reaches 12%. The reserves of mined uranium available in Russia have an electrical potential of 15 trillion. kWh, this is as much as all our power plants can produce in 35 years. Today only nuclear energy
is capable of dramatically and in a short period of time weakening the greenhouse effect. A pressing issue is the safety of nuclear power plants. The year 2000 marked the beginning of the transition to fundamentally new approaches to regulation and ensuring radiation safety of nuclear power plants.
Over the 40 years of development of nuclear energy in the world, about 400 power units have been built in 26 countries. The main advantages of nuclear energy are high final profitability and the absence of emissions of combustion products into the atmosphere; the main disadvantages are the potential danger of radioactive contamination of the environment with fission products of nuclear fuel in an accident and the problem of reprocessing used nuclear fuel.
Non-traditional (alternative energy)
1. Solar energy. This is the use of solar radiation to produce energy in some form. Solar energy uses a renewable energy source and has the potential to become environmentally friendly in the future.
Advantages of solar energy:
– Public availability and inexhaustibility of the source;
– Theoretically, completely safe for the environment.
Disadvantages of solar energy:
– The flow of solar energy on the Earth’s surface is highly dependent on latitude and climate;
– The solar power plant does not work at night and does not work efficiently enough in the morning and evening twilight;
Photovoltaic cells contain toxic substances such as lead, cadmium, gallium, arsenic, etc., and their production consumes a lot of other hazardous substances.
2. Wind energy. This is a branch of energy specializing in the use of wind energy - the kinetic energy of air masses in the atmosphere. Since wind energy is a consequence of the activity of the sun, it is classified as a renewable form of energy.
Prospects for wind energy.
Wind energy is a rapidly growing industry, and at the end of 2007 the total installed capacity of all wind turbines was 94.1 gigawatts, having increased fivefold since 2000. Wind farms worldwide produced about 200 billion kWh in 2007, representing approximately 1.3% of global electricity consumption. Coastal wind farm Middelgrunden, near Copenhagen, Denmark. At the time of construction it was the largest in the world.
Opportunities for implementing wind energy in Russia. In Russia, the potential of wind energy remains practically unrealized to this day. A conservative attitude towards the long-term development of the fuel and energy complex practically hinders the effective implementation of wind energy, especially in the Northern regions of Russia, as well as in the steppe zone of the Southern Federal District, and in particular in the Volgograd region.
3. Thermonuclear energy. The sun is a natural thermonuclear reactor. An even more interesting, although relatively distant, prospect is the use of nuclear fusion energy. Thermonuclear reactors, according to calculations, will consume less fuel per unit of energy, and both this fuel itself (deuterium, lithium, helium-3) and the products of their synthesis are non-radioactive and, therefore, environmentally safe.
Prospects for thermonuclear energy. This area of energy has enormous potential; currently, within the framework of the ITER project, in which Europe, China, Russia, the USA, South Korea and Japan participate, the largest thermonuclear reactor is being built in France, the goal of which is to develop CTS (Controlled Thermonuclear Fusion) to a new level. Construction is scheduled to be completed in 2010.
4. Biofuel, biogas. Biofuel is fuel from biological raw materials, usually obtained by processing sugar cane stalks or rapeseed seeds, corn, and soybeans. There are liquid biofuels (for internal combustion engines, for example, ethanol, methanol, biodiesel) and gaseous (biogas, hydrogen).
Types of biofuel:
– Biomethanol
– Bioethanol
– Biobutanol
– Dimethyl ether
– Biodiesel
– Biogas
– Hydrogen
At the moment, the most developed are biodiesel and hydrogen.
5. Geothermal energy. Hidden beneath Japan's volcanic islands are vast amounts of geothermal energy, which can be harnessed by extracting hot water and steam. Advantage: It emits approximately 20 times less carbon dioxide when generating electricity, reducing its impact on the global environment.
6. Energy of waves, ebbs and flows. In Japan, the most important source of energy is wave turbines, which convert the vertical movement of ocean waves into air pressure that rotates the turbines of electric generators. There are a large number of buoys installed on the coast of Japan that use the energy of tides. This is how ocean energy is used to ensure the safety of ocean transport.
The enormous potential of solar energy could theoretically provide all the world's energy needs. But the efficiency of converting heat into electricity is only 10%. This limits the possibilities of solar energy. Fundamental difficulties also arise when analyzing the possibilities of creating high-power generators using wind energy, tides, geothermal energy, biogas, vegetable fuel, etc. All this leads to the conclusion that the capabilities of the considered so-called “renewable” and relatively environmentally friendly energy resources are limited, at least in the relatively near future. Although the effect of their use in solving certain particular problems of energy supply can already be very impressive.
Of course, there is optimism about the possibilities of thermonuclear energy and other effective methods of generating energy, which are being intensively studied by science, but at the modern scale of energy production. The practical development of these possible sources will require several decades due to the high capital intensity and corresponding inertia in the implementation of projects.
Research works of students:
1. Special report “Green Energy” for the future: “Japan is the world leader in the production of solar electricity. 90% of the solar energy produced in Japan comes from solar panels in ordinary homes. The Japanese government has set a goal in 2010 to obtain approximately 4.8 million kW of energy from solar panels. Electricity production from biomass in Japan. Methane gas is released from kitchen waste. This gas powers an engine that generates electricity, and also creates favorable conditions for protecting the environment.
The electric power industry, like other industries, has its own problems and development prospects.
Currently, the Russian electric power industry is in crisis. The concept of “energy crisis” can be defined as a tense state that has developed as a result of a discrepancy between the energy needs of modern society and energy reserves, including due to the irrational structure of their consumption.
In Russia it is currently possible to distinguish 10 groups most pressing problems:
- 1). The presence of a large proportion of physically and morally outdated equipment. An increase in the share of physically worn-out assets leads to an increase in the accident rate, frequent repairs and a decrease in the reliability of energy supply, which is aggravated by excessive utilization of production capacities and insufficient reserves. Today, wear and tear of equipment is one of the most important problems in the electric power industry. At Russian power plants it is very high. The presence of a large proportion of physically and morally obsolete equipment complicates the situation with ensuring the safety of power plants. About one fifth of production assets in the electric power industry are close to or have exceeded their design service life and require reconstruction or replacement. Equipment upgrades are being carried out at an unacceptably low pace and in clearly insufficient quantities (table).
- 2). The main problem of energy is that, along with ferrous and non-ferrous metallurgy, energy has a powerful negative impact on the environment. Energy enterprises generate 25% of all industrial emissions.
In 2000, the volume of emissions of harmful substances into the atmosphere amounted to 3.9 tons, including emissions from thermal power plants - 3.5 million tons. Sulfur dioxide accounts for up to 40% of total emissions, solids - 30%, nitrogen oxides - 24%. That is, thermal power plants are the main cause of the formation of acid residues.
The largest air pollutants are Raftinskaya State District Power Plant (Asbest, Sverdlovsk region) - 360 thousand tons, Novocherkasskaya (Novocherkassk, Rostov region) - 122 thousand tons, Troitskaya (Troitsk-5, Chelyabinsk region) - 103 thousand tons, Verkhnetagilskaya (Sverdlovsk region) - 72 thousand tons.
The energy sector is also the largest consumer of fresh and sea water, spent on cooling units and used as a heat carrier. The industry accounts for 77% of the total volume of fresh water used by Russian industry.
The volume of wastewater discharged by industry enterprises into surface water bodies in 2000 amounted to 26.8 billion cubic meters. m. (5.3% more than in 1999). The largest sources of water pollution are thermal power plants, while state district power plants are the main sources of air pollution. This is CHPP-2 (Vladivostok) - 258 million cubic meters. m, Bezymyanskaya CHPP (Samara region) - 92 million cubic meters. m, CHPP-1 (Yaroslavl) - 65 million cubic meters. m, CHPP-10 (Angarsk, Irkutsk region) - 54 million cubic meters. m, CHPP-15 and Pervomaiskaya CHPP (St. Petersburg) - a total of 81 million cubic meters. m.
The energy sector also produces a large amount of toxic waste (slag, ash). In 2000, the volume of toxic waste amounted to 8.2 million tons.
In addition to air and water pollution, energy enterprises pollute soils, and hydroelectric power plants have a strong impact on river regimes, river and floodplain ecosystems.
- 3). Strict tariff policy. In the electric power industry, questions have been raised about the economical use of energy and tariffs for it. We can talk about the need to save generated electricity. Indeed, the country currently uses 3 times more energy per unit of production than the United States. There is a lot of work to be done in this area. In turn, energy tariffs are growing at a faster pace. The current tariffs in Russia and their ratio do not correspond to world and European practice. The existing tariff policy has led to unprofitable activities and low profitability of a number of regional energy companies.
- 4). A number of areas are already experiencing difficulties in providing electricity. Along with the Central region, electricity shortages are observed in the Central Black Earth, Volga-Vyatka and North-Western economic regions. For example, in the Central Economic Region in 1995, a huge amount of electricity was produced - 19% of the all-Russian indicators (154.7 billion kW), but it was all consumed within the region.
- 5). Capacity growth is decreasing. This is due to low-quality fuel, worn-out equipment, work to improve the safety of units and a number of other reasons. The underutilization of hydroelectric power plants is due to the low water content of rivers. Currently, 16% of the capacity of Russian power plants has already exhausted its resource. Of these, hydroelectric power stations account for 65%, thermal power plants - 35%. The commissioning of new capacities decreased to 0.6 - 1.5 million kW per year (1990-2000) compared to 6-7 million kW per year (1976-1985).
- 6). The emerging opposition from the public and local authorities to the placement of electric power facilities due to their extremely low environmental safety. In particular, after the Chernobyl disaster, many survey work, construction and expansion of nuclear power plants at 39 sites with a total design capacity of 109 million kW were stopped.
- 7). Non-payments, both from electricity consumers and from energy companies for fuel, equipment, etc.;
- 8). Lack of investment, associated both with the current tariff policy and with the financial “opacity” of the industry. The largest Western strategic investors are ready to invest in the Russian electric power industry only if tariffs increase in order to ensure return on investment.
- 9). Interruptions in power supply to certain regions, in particular Primorye;
- 10). Low efficiency of energy resources. This means that 57% of energy resources are lost annually. Most losses occur in power plants, in engines that directly use fuel, and in technological processes where fuel serves as a raw material. When transporting fuel, large losses of energy resources also occur.
As for development prospects electric power industry in Russia, then, despite all its problems, the electric power industry has sufficient prospects.
For example, the operation of thermal power plants requires the extraction of a huge amount of non-renewable resources, has a fairly low efficiency, and leads to environmental pollution. In Russia, thermal power plants operate on fuel oil, gas, and coal. However, at this stage, regional energy companies with a high share of gas in the structure of the fuel balance are attractive, as a more efficient and environmentally beneficial fuel. In particular, it can be noted that gas-fired power plants emit 40% less carbon dioxide into the atmosphere. In addition, gas stations have a higher installed capacity utilization rate compared to oil and coal stations, have a more stable heat supply and do not incur fuel storage costs. Gas-fired stations are in better condition than coal and oil-fired ones, since they were put into operation relatively recently. Gas prices are also regulated by the state. Thus, the construction of thermal power plants using gas as fuel becomes more promising. Also, at thermal power plants it is promising to use dust cleaning equipment with the highest possible efficiency, while the resulting ash can be used as a raw material in the production of building materials.
The construction of a hydroelectric power station, in turn, requires the flooding of a large amount of fertile land, or as a result of water pressure on the earth's crust, a hydroelectric power station can cause an earthquake. In addition, fish stocks in rivers are declining. The construction of relatively small hydroelectric power plants, which do not require major capital investments and operate automatically mainly in mountainous areas, as well as the embankment of reservoirs to free up fertile lands, is becoming promising.
As for nuclear energy, the construction of nuclear power plants has a certain risk, due to the fact that it is difficult to predict the scale of the consequences if the operation of nuclear power units becomes complicated or under force majeure circumstances. Also, the problem of disposal of solid radioactive waste has not been resolved, and the protection system is also imperfect. Nuclear power engineering has the greatest prospects in the development of thermonuclear power plants. This is an almost eternal source of energy, almost harmless to the environment. The development of nuclear power in the near future will be based on the safe operation of existing capacities, with the gradual replacement of first-generation units with the most advanced Russian reactors. The largest expected increase in capacity will occur due to the completion of construction of already started stations.
There are 2 opposing concepts for the further existence of nuclear power in the country.
- 1. Official, which is supported by the President and the Government. Based on the positive features of nuclear power plants, they propose a program for the broad development of the Russian electric power industry.
- 2. Ecological, headed by Academician Yablokov. Proponents of this concept completely reject the possibility of new construction of nuclear power plants, both for environmental and economic reasons.
There are also intermediate concepts. For example, a number of experts believe that it is necessary to introduce a moratorium on the construction of nuclear power plants based on the shortcomings of nuclear power plants. Others suggest that stopping the development of nuclear power could lead to Russia completely losing its scientific, technical and industrial potential in nuclear power.
Based on all the negative impacts of traditional energy on the environment, much attention is paid to studying the possibilities of using non-traditional, alternative energy sources. The energy of ebbs and flows and the internal heat of the Earth have already received practical application. Wind power plants are available in residential settlements in the Far North. Work is underway to study the possibility of using biomass as an energy source. In the future, solar energy may play a huge role.
The experience of developing the domestic electric power industry has produced the following principles of location and operation of enterprises this industry:
- 1. concentration of electricity production at large regional power plants using relatively cheap fuel and energy resources;
- 2. combining the production of electricity and heat for district heating of populated areas, especially cities;
- 3. extensive development of hydro resources, taking into account the integrated solution of problems in the electric power industry, transport, and water supply;
- 4. the need to develop nuclear energy, especially in areas with a tense fuel and energy balance, taking into account the safety of using nuclear power plants;
- 5. creation of energy systems that form a single high-voltage network of the country.
At the moment, Russia needs a new energy policy that would be sufficiently flexible and provide for all the features of this industry, including the features of location. As main tasks of Russian energy development the following can be distinguished:
b Reducing the energy intensity of production.
ь Preservation of the integrity and development of the Unified Energy System of Russia, its integration with other energy associations on the Eurasian continent;
b Increasing the power factor of power plants, increasing operating efficiency and ensuring sustainable development of the electric power industry based on modern technologies;
ь Complete transition to market relations, liberation of energy prices, complete transition to world prices.
ь Speedy renewal of the power plant fleet.
b Bringing the environmental parameters of power plants to the level of world standards, reducing the harmful impact on the environment
Based on these tasks, a “General Scheme for the Location of Electric Power Industry Facilities until 2020” was created, approved by the Government of the Russian Federation. (diagram 2)
The priorities of the General Scheme within the established guidelines for long-term state policy in the electricity sector are:
ь accelerated development of the electric power industry, creation of an economically sound structure of generating capacities and power grid facilities in it to reliably supply the country's consumers with electric and thermal energy;
b optimization of the fuel balance of the electric power industry through the maximum possible use of the development potential of nuclear, hydraulic, and coal-fired thermal power plants and reducing the use of gas in the fuel balance of the industry;
b creation of a network infrastructure that is developing at a faster pace than the development of power plants and ensures the full participation of energy companies and consumers in the functioning of the electric energy and power market, strengthening intersystem connections that guarantee the reliability of mutual supplies of electric energy and power between the regions of Russia, as well as the possibility of exporting electric energy ;
b minimizing specific fuel consumption for the production of electrical and thermal energy through the introduction of modern, highly economical equipment operating on solid and gaseous fuels;
b reduction of the technogenic impact of power plants on the environment through the efficient use of fuel and energy resources, optimization of the industrial structure of the industry, technological re-equipment and decommissioning of obsolete equipment, increasing the scope of environmental protection measures at power plants, implementing programs for the development and use of renewable energy sources.
Based on the results of monitoring, a report on the progress of implementation of the General Scheme is submitted annually to the Government of the Russian Federation. In a few years, it will be clear how effective it is and how much its provisions regarding the use of all prospects for the development of Russian energy are being implemented.
In the future, Russia must abandon the construction of new large thermal and hydraulic power plants, which require huge investments and create environmental tension. It is planned to build low- and medium-power thermal power plants and small nuclear power plants in remote northern and eastern regions. In the Far East, it is planned to develop hydropower through the construction of a cascade of medium and small hydroelectric power stations. New thermal power plants will be built on gas, and only in the Kansk-Achinsk basin is it planned to build powerful condensing power plants due to cheap, open-pit coal mining. There are prospects for the use of geothermal energy. The areas most promising for the widespread use of thermal waters are Western and Eastern Siberia, as well as Kamchatka, Chukotka, and Sakhalin. In the future, the scale of use of thermal waters will steadily increase. Research is being carried out to involve inexhaustible energy sources, such as the energy of the sun, wind, tides, etc., into economic circulation, which will make it possible to save energy resources in the country, especially mineral fuels.
B.P. Varnavsky, member of the editorial board of NT, director for energy production and capital construction, EuroSibEnergo OJSC, Moscow
On the importance of thermal power plants in the Soviet Union
In the development of the energy system of the Soviet Union, combined heat and power plants (CHPs) played a key role. Everyone understood perfectly well that the intensive development of industry required a huge amount of electricity and, most importantly, industrial thermal energy. Based on this, it was thermal power plants that received fundamental development as a key form of energy supply to large industrial enterprises and cities in which (or near which) these industrial facilities were located.
For example, the Omsk Oil Refinery, included in the ranking of the world's 100 best oil refineries, is the only enterprise on this list that does not have its own block station, but receives heat and electricity from external thermal power plants.
In foreign countries, they followed a different principle for the development of the energy supply scheme - each large industrial enterprise (with large volumes of thermal energy consumption, with a high yield of secondary resources and the need for their recycling) must have its own block station, which will allow it to meet its needs for electricity and heat - energy. In this case, it becomes possible to optimize the energy supply scheme of any such enterprise, avoiding intermediaries.
Speaking about domestic thermal power plants, the number of which rapidly increased until 1990, it should be noted that in the Soviet years a type of thermal power plant was formed, which was (depending on the type of load) a balanced set of turbines of the PT, T and R types. A project appeared that received the name “Typical design of CHPP-300”, which was later modernized into “Typical project of CHPP-350”, which greatly simplified the design of thermal power plants. It is known that, having standard solutions, it is much easier to develop a project, and there is no need to attract highly qualified specialists at this stage. The presence of such a standard project contributed to the emergence of unified building structures, individual elements, components, circuit solutions (including a thermal circuit, excluding the type of fuel), etc. And today we work on this unified equipment almost throughout the country.
Operation of thermal power plants in the post-Soviet period
Today one can argue about the correctness of the chosen direction for the development of the energy system in
Soviet Union, but, of course, the choice made many years ago seriously affected the economic performance of thermal power plants in the post-Soviet era, when the industrial load of many of them, for various reasons, decreased significantly, and in some cases fell to zero. Since now all industrial enterprises operate in market conditions, their production plan fluctuations are quite large, while the daily heat load of the enterprise can change two or more times (for example, fall from 800 to 400 t/h). As the practice of operating thermal power plants in the post-Soviet period has shown, the main troubles of thermal power plants were their underutilization and inflexibility in responding to changes in heat loads. Thus, thermal power plants and energy supply schemes from them, created in Soviet times, were not ready to work in market conditions.
As a result, problems arose with heat loads for the heat supply needs of other (non-industrial) urban facilities, which also decreased due to the disconnection of individual consumers from the thermal power plant. Suffice it to recall the boom that took place in 1990-2000, when in various regions of the country the decentralization of heat supply systems began due to the sometimes thoughtless and not supported by feasibility study construction of attached and roof-top boiler houses, as well as the equipping of multi-storey residential buildings with apartment boilers. Moreover, it was believed that all these new technical solutions were much more economical and profitable compared to centralized heat supply (DH) systems from large boiler houses and thermal power plants, but their operation (with the exception of certain cases) showed the opposite. And today, CHP plants are still considered the main element of district heating systems.
When considering a central heating system from a combined heat and power plant, we must not forget about reasonable heat supply radii. Probably, heating network radii of 20-30 km today cannot be considered acceptable values, not only from the point of view of efficiency, but also from the point of view of system reliability. We must not forget about the issue of reliability of the system as a whole and in the presence of a large thermal power plant in the city, on which 500 thousand residents “hang”, which is the only source for a particular territory. At the same time, increasing reliability through redundancy at thermal power plants is very expensive. First of all, at a minimum, it must be protected from various types of emergency situations in order to be able to cover its own needs and provide heat load to consumers. As for the electrical load, it is possible to “lose” it (of course, it is undesirable), because its redundancy can be provided by a common power system. But how not to “lose” the heat load of the station and the main heating network? Is it necessary to reserve main heating networks from thermal power plants (for example, with a diameter of DN 1200 mm) with corresponding colossal financial investments? These issues have still not been resolved.
There is one more very important detail that needs to be paid attention to - the functioning of the heat supply system in Soviet times. Thus, the Soviet Union spent 50% of the extracted fuel natural resources on providing thermal energy to consumers; for electricity - 25%. However, the normative and technical standardized arrangement of electricity production was two orders of magnitude higher than that of thermal energy production. In the heat supply sector, there were too few regulations that would allow for the creation of reliable energy sources and heating networks, in contrast to the electricity sector. If we follow the reliability criterion “n-1” (quantitative redundancy), adopted in the electric power industry, then it is difficult to transfer it to the thermal power industry, since it sharply increases capital costs. There are no real revolutionary ways to improve the reliability of district heating systems with large energy sources.
In our opinion, increasing the reliability of any district heating system, the basis of which is a combined heat and power plant, does not consist in implementing measures based on the “p-1” criterion, but in increasing the level of reliability of individual elements of the system (auxiliary, general station equipment and heating network equipment) to the requirements for the main equipment of the station, and the corresponding attitude towards it (i.e. in this case it will be considered that the failure of system elements is comparable to the failure of the main equipment). For example, quantitative redundancy of main heating networks, when the existing main supply of heating networks of low quality is supplemented with a third pipeline of similar quality, is unlikely to lead to an actual increase in the reliability of the system while its cost increases significantly. But if there is a high-quality backup of the same pipelines of heating networks, which will allow you to practically forget about them for the declared resource of 25 years or more, then this is a completely different way to increase reliability, which in the end turns out to be cheaper than quantitative backup.
The situation is similar with pumping equipment. This may be a revolutionary idea, but if the system is operated by a network pump with a high working life (for example, 15 years), which is achieved through the use of other materials, technical solutions (this is the task of the manufacturer), which has the same reliability as the source of heat supply, then their number at the thermal power plant can be reduced to one. If such an approach to the level of requirements for auxiliary and other equipment in terms of reliability prevails, then manufacturing companies will make appropriate equipment according to these requirements. At the same time, the number of various fittings is reduced, the circuits are simplified, which will make them more reliable and understandable, despite the increase in capital costs. These schemes are easier to automate, it is easier to build an automated process control system on them, because the algorithms are simpler. If this approach is used in the development of technical progress, then such centralized systems will have the right to continue life.
The next serious question is what to do with thermal power plants that have exhausted their service life? Today there are projects to replace most of them. As for the electrical load, no questions arise here. But what to do with the thermal load is not clear. On average, the standard service life of the main equipment of a station is 250 thousand hours, and in Russia most of the equipment of thermal power plants has long expired this established standard service life. For example, the second stage of the Avtozavodskaya CHPP (Nizhny Novgorod) worked for 400 thousand hours, and the hot water load of 500 thousand residents of Nizhny Novgorod “sits” on it. Finally, a decision was made to replace the equipment of the second stage of this station. Question: how to replace capacity at existing thermal power plants? Obviously, this should be the same site or close to it. Of course, the best option is to completely liquidate the old station and build a new modern one, but it doesn’t work that way. For example, we considered a lot of options for Irkutsk: how to replace old thermal power plants. It is clear that it is necessary to build up the appropriate capacity, and then remove the worn-out capacity, everything is logical, but where to get the free space. As a rule, almost all thermal power plants are industrial heating plants; they are squeezed on all sides by all kinds of combines and factories, i.e. Thermal power plants are in absolute cramped conditions. The construction of a thermal power plant on a new site with the transfer of heating networks is a very expensive pleasure. Thus, the relevance of the issue of replacing outdated thermal power plants is increasing every day, but there are no established principles for replacement; they need to be created. Someone needs to take the initiative to resolve this issue.
Is this the task of each energy company individually or is it the task of the state, which must monitor the implementation of the energy strategy? But the replacement process is a strategic issue, not a tactical one. But today we are unlikely to get any help from the state in solving this problem. Since we inherited just such a system from the Soviet Union, today we must know what to do with it next.
All thermal power plants, as a rule, are participants in the wholesale electricity market. In this market, the interests of district heating, no matter how we declare them, are not taken into account. Although, in principle, priority is formally given: when operating a thermal power plant on the market or to cover the load of the dispatch schedule, there is an obvious decision made that it should operate under conditions of 100% output of electricity generated in the combined cycle; CHP operation in condensation mode is not allowed, etc. But in real life, it is difficult for CHP plants to comply with these priorities, which is why it is not always possible to maintain the economic indicators that are protected in tariffs, etc. Therefore, more stringent boundaries should be established on this issue, and in this position I support A.B. Bogdanov is that priorities should be given to the cost of electricity generated in the combined cycle, which is supplied by thermal power plants to urban residents, which he wrote about in a number of publications on the pages of NT magazine (see series of articles
A.B. Bogdanov “The boiler installation of Russia is a disaster on a national scale” in the NT magazine, published in the period 2006-2007 - Approx. ed.). Thus, the economic mechanisms for the operation of thermal power plants are underdeveloped, as a result of which their current situation throughout the country is very unstable.
We carried out an analysis of the increase in heat load at thermal power plants in various cities of Russia, it turned out that these indicators basically stand still, because a new connection to a thermal power plant looks more expensive than building your own boiler house. Until we change the state of things on this issue, we will mark time. Let us give an example of the Ust-Ilimsk Thermal Power Plant, which at one time was built to supply energy to a pulp and paper mill located in close proximity to this power plant. In recent years, the plant has changed its nomenclature and reduced production volumes, which, naturally, affected the amount of heat load and the operation of the thermal power plant and the ensuing problems that were discussed above. The pulp and paper mill began to deal with issues of energy saving; first of all, they began to utilize the waste of the enterprise (bark, sawdust, etc.), accumulated over the years, the combustion of which makes it possible to fully cover the mill's own needs for thermal energy. Thus, today this enterprise no longer needs the previous volumes of heat load. The management of the Ust-Ilimskaya CHPP, understanding how this situation could affect the economic indicators of the power plant, did its best to accommodate the pulp and paper mill, but bidding on the cost of the supplied gigacalorie of thermal energy is only possible up to a certain value - up to its cost, below which the energy supply The company cannot go down. Thus, even our proposal for the supply of thermal energy from thermal power plants at cost was inferior to the cost of thermal energy generated by the plant from its secondary resources. As a result, the thermal power plant lost most of its industrial output and, accordingly, the technical and economic indicators at the station seriously dropped. We have given only one example, but it is not the only one; this trend, detrimental to existing thermal power plants, continues. Given this undesirable trend, we must understand how we can modernize the existing fleet today to use P-type turbines, which are essentially unnecessary when the steam load is lost. Here various schemes can be implemented that would allow us to use type P machines for the heat supply needs of non-industrial consumers. Everything is good, except for one thing - we need to expand the market for district heating from combined heat and power plants.
For example, in Irkutsk, the expansion of this market is due to the purchase of communal boiler houses and heating networks, for which huge amounts of money are spent. Then, as a rule, boiler houses are closed, the largest of them are transferred to peak mode. Heat networks accepted on the balance sheet of the generating company are necessarily modernized - their condition is brought to an acceptable level, for which it is necessary to invest 3-4 times more money in them than in the existing (main) heat networks of the generating company. In this case, it becomes possible to additionally load the thermal power plant only after the heat load of the boiler houses has been “transferred” to it. Loading the thermal power plant in this way makes it possible to partially reimburse the costs that previously arose due to the loss of industrial load. But similar and other programs (on energy saving, increasing reliability) need government incentives, at least similar to what is available in the electric power industry, because For private companies that have entered the “big” energy sector today, such programs require colossal cash injections. At the same time, local authorities do not always make such decisions as in Irkutsk.
As another solution, we will give the example of St. Petersburg, where there are quite a lot of efficient boiler houses on the balance sheet of the State Unitary Enterprise “TEK SPb”. Such boiler houses turn out to be quite competitive with thermal power plants, not in essence, but in terms of general economic indicators.
We have given several examples, from which it is clear that in each individual case it is necessary to look for mechanisms that will allow for the further development of combined heat and power generation, taking into account the introduction of new cycles, for example, the combined cycle cycle.
When introducing a CCGT unit in Russia, the first question that arose was its economical loading. As soon as you “hang” the heating load on the CCGT unit, in the summer you still have to work in inefficient modes due to a decrease in the heat load, because There is only a load on the DHW. For example, during the reconstruction of the Avtozavodskaya CHPP to replace the second stage of the station, we first of all equalized the parameters for live steam, selected steam, and district heating outputs so that the new replacement unit could operate in parallel with other lines. This sharply narrows the choice of gas turbines, since the turbines must provide exhaust parameters such that the CCGT recovery boiler produces steam with parameters of 140 atm, 540 °C. But in the future, this solution will make it possible to load this new unit based on the CCGT at full capacity , and the damper will be less economical equipment (despite the fact that it has high steam parameters). Thus, when modernizing and reconstructing thermal power plants, especially when introducing CCGT units, it is necessary to use appropriate progressive schemes, which depend on a number of factors. The main criterion, of course, is the existing and future load of the thermal power plant.
Russia will remain a country in which the cost of production, all other things being equal, will always be higher due to the difference in average annual heating temperatures compared to foreign analogues. Accordingly, the volume of fuel and energy resources (FER) required to produce any unit of product in Russia will always be objectively higher compared to similar products produced abroad. Are we doomed to be forever uncompetitive due to objective reasons or not? There is only one way out: Russia needs to be half a length ahead of other countries in terms of the use and generation of various types of energy. For Russia, the only thing that makes the situation easier is that our country has its own fuel and energy resources, and not imported ones, as in many foreign countries; accordingly, we get them cheaper. It is necessary to constantly reduce the amount of the fuel component in the production of any type of product, including heat and electricity. This requires not the isolated work of all Russian generating companies, but the coordination of all our efforts in terms of carrying out relevant research, R&D aimed at improving existing energy supply systems, etc.
Here it is also necessary to note one more point, which indirectly relates to the issue raised above. Today, any project for the construction of any facility undergoes a state examination for compliance with the required criteria (for example, structural strength, etc.). In this regard, until the project passes this examination, a construction permit will not be obtained. Everything is fine, but the existing examination does not include criteria for the energy component. In our opinion, at the level of state examination of the project, the energy efficiency parameters of an object (primarily a large one) should be equated to its reliability parameters (strength, structural safety, etc.). Yes, this is an administrative resource, but it is necessary in the existing Russian conditions. Thus, at the project stage, a decision must be made on the feasibility of constructing a particular facility, taking into account the parameters (criteria) indicated above.
When we talk about the design of global facilities, it is necessary to take into account world experience, and at large enterprises that are located within the city, we must act in such a way that the “big” energy sector does not end up in the position of the Ust-Ilimsk Thermal Power Plant. Replacement at city-forming thermal power plants in today's conditions should be based on the guaranteed load of heat supply to the population, and not on the industrial load, which should be the concern of industrial enterprises themselves!
In conclusion, it should be noted that the “big” energy industry should not forget about new technologies, for example, technology such as heat pumps. For example, in Baikalsk (Irkutsk region), we faced a dilemma when introducing a heat pump in the presence of cheap electricity generated at a hydroelectric power station. As a result, we decided to install a heat pump in order to study the features of its operation, which should be taken into account in the further implementation of this technology. Perhaps this position is flawed in some ways, but today everything cannot be reduced to bare profit, especially in the energy sector; there must also be so-called altruistic (non-profit-making) programs.
To assess the prospects of thermal power plants, it is first necessary to understand their advantages and disadvantages in comparison with other sources of electricity.
The advantages include the following.
- 1. Unlike hydroelectric power plants, thermal power plants can be placed relatively freely, taking into account the fuel used. Gas and fuel oil thermal power plants can be built anywhere, since the transportation of gas and fuel oil is relatively cheap (compared to coal). It is advisable to locate pulverized coal power plants near coal mining sources. By now, “coal” thermal power engineering has developed and has a pronounced regional character.
- 2. The specific cost of installed power (cost of 1 kW of installed power) and the construction period of thermal power plants are significantly less than those of nuclear power plants and hydroelectric power plants.
- 3. Electricity production at thermal power plants, unlike hydroelectric power plants, does not depend on the season and is determined only by the delivery of fuel.
- 4. The areas of alienation of economic land for thermal power plants are significantly smaller than for nuclear power plants, and, of course, cannot be compared with hydroelectric power plants, the impact of which on the environment may be far from regional in nature. Examples include cascades of hydroelectric power stations on the river. Volga and Dnieper.
- 5. At thermal power plants, you can burn almost any fuel, including the lowest-grade coals, ballasted with ash, water, and rock.
- 6. Unlike nuclear power plants, there are no problems with the disposal of thermal power plants at the end of their service life. As a rule, the infrastructure of thermal power plants significantly outlasts the main equipment (boilers and turbines) installed on it, and the buildings, turbine hall, water supply and fuel supply systems, etc., which make up the bulk of the assets, continue to serve for a long time. Most thermal power plants built over 80 years ago according to the GOELRO plan are still operating and will continue to operate after the installation of new, more advanced turbines and boilers.
Along with these advantages, TPP also has a number of disadvantages.
- 1. Thermal power plants are the most environmentally “dirty” sources of electricity, especially those that run on high-ash sulfur fuel. It is true to say that nuclear power plants that do not have constant emissions into the atmosphere, but create a constant threat of radioactive contamination and have problems storing and reprocessing spent nuclear fuel, as well as disposal of the nuclear power plant itself after the end of its service life, or hydroelectric power plants that flood vast areas of economic land and change regional climate, are environmentally “cleaner” is possible only with a significant degree of convention.
- 2. Traditional thermal power plants have relatively low efficiency (better than that of nuclear power plants, but significantly worse than that of combined cycle gas turbine units).
- 3. Unlike hydroelectric power plants, thermal power plants are difficult to cover the variable part of the daily electrical load schedule.
- 4. Thermal power plants significantly depend on the supply of fuel, often imported.
Despite all these shortcomings, thermal power plants are the main producers of electricity in most countries of the world and will remain so for at least the next 50 years.
The prospects for the construction of powerful condensing thermal power plants are closely related to the type of organic fuel used. Despite the great advantages of liquid fuel (oil, fuel oil) as an energy carrier (high calorie content, ease of transportation), its use at thermal power plants will be increasingly reduced not only due to limited reserves, but also due to its great value as a raw material for petrochemical industry. For Russia, the export value of liquid fuel (oil) is also of considerable importance. Therefore, liquid fuel (fuel oil) at thermal power plants will be used either as a reserve fuel at gas-oil thermal power plants, or as an auxiliary fuel at pulverized coal thermal power plants, ensuring stable combustion of coal dust in the boiler under certain conditions.
The use of natural gas in condensing steam turbine thermal power plants is irrational: for this, it is necessary to use utilization-type combined cycle gas plants, the basis of which are high-temperature gas turbine units.
Thus, the long-term prospect of using classical steam turbine thermal power plants both in Russia and abroad is primarily associated with the use of coal, especially low-grade coal. This, of course, does not mean the cessation of operation of gas-oil thermal power plants, which will be gradually replaced by steam turbine units.