Problems and prospects of energy development. Thermal energy Advanced technologies of coal energy

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The presentation is an additional material to the lessons on energy development. Energy of any country is the basis for the development of productive forces, 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 search work of students (work with the magazine "Japan Today"), creative work of students (posters). The presentation can be used in geography lessons in grades 9 and 10, in extracurricular activities (elective classes, elective courses), in holding the Geography Week "April 22 - Earth Day", in ecology and biology lessons "Global problems of mankind. Raw materials and energy problem ”.

In my work, I used the method of problem learning, which consisted in creating problem situations in front of students and resolving them in the process of joint activities of students and teachers. At the same time, the maximum independence of students was taken into account under the general guidance of a teacher who guides the activities of students.

Problem-based learning allows not only to form the necessary system of knowledge, abilities and skills among students, to achieve a high level of development of schoolchildren, but, which is especially important, it allows to form a special style of mental activity, research activity and independence of students. When working with this presentation, students are shown an actual direction - the research activities of schoolchildren.

The industry unites a group of industries engaged in the extraction and transportation of fuel, energy generation and transmission to the consumer.

Natural resources that are used for energy production 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 - 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 contains 12% of the world's coal reserves, 13% of oil and 36% of the world's natural gas reserves, which are sufficient to fully meet their own needs and for export to neighboring states. 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.

The current rate of energy consumption is 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 aggravated by the discrepancy between the structure of reserves and consumption of organic raw materials. So, 80% of fossil fuel reserves are coal and only 20% are oil and gas, while 8/10 of modern energy consumption is oil and gas.

Consequently, the time frame is further narrowed. However, only today mankind is getting rid of the ideological ideas that they are practically endless. Mineral resources are limited, virtually irreplaceable.

Energy problem.

Today, the world's energy industry is based on energy sources:

- Combustible minerals;
- Combustible organic minerals;
- Energy of rivers. Non-traditional forms of energy;
- The energy of the atom.

With the current rate of rise in the price of the Earth's fuel resources, the problem of using renewable energy sources is becoming more and more urgent and characterizes the energy and economic independence of the state.

Advantages and disadvantages of TPP.

TPP advantages:

1. The cost of electricity at hydroelectric power plants is very low;
2. Generators of hydroelectric power stations can be quickly switched on and off depending on energy consumption;
3. There is no air pollution.

Disadvantages of TPP:

1. The construction of a hydroelectric power station can be more time consuming and expensive than other energy sources;
2. Reservoirs can cover large areas;
3. Dams can damage fisheries by blocking the path to spawning grounds.

Advantages and disadvantages of hydroelectric power plants.

Hydroelectric power station advantages:
- They are built quickly and cheaply;
- They work in a constant mode;
- Are located almost everywhere;
- The prevalence of thermal power plants in the energy sector of the Russian Federation.

Disadvantages of hydroelectric power plants:

- Consume a lot 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 emitted into the atmosphere;
- Major environmental pollutants.

In the structure of electricity generation in the world, the first place belongs to thermal power plants (TPP) - their share is 62%.
An alternative to fossil fuels and a renewable energy source is hydropower. Hydroelectric power plant (HPP)- a power plant that uses the energy of the water flow as a source of energy. Hydroelectric power plants are usually built on rivers with dams and reservoirs. Hydropower is the generation of electricity through the use of renewable river, tidal, geothermal water resources. This use of renewable water resources implies flood management, strengthening of river beds, transfer of water resources to areas suffering from drought, conservation of underground flow waters.
However, here, too, the energy source is rather severely limited. This is due to the fact that large rivers, as a rule, are far away from industrial centers or their capacities are 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 in Russia have an electrical potential of 15 trillion. kWh, this is as much as all our power plants can generate in 35 years. Today, only nuclear power
capable of sharply and for short term weaken the phenomenon of the greenhouse effect. NPP safety is an urgent problem. The year 2000 marked the beginning of the transition to fundamentally new approaches to standardizing and ensuring the radiation safety of nuclear power plants.
Over 40 years of development of nuclear power in the world, about 400 power units have been built in 26 countries of the world. The main advantages of nuclear energy are high ultimate 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 by fission products of nuclear fuel in an accident and the problem of reprocessing used nuclear fuel.

Unconventional (alternative energy)

1. Solar energy... It is the use of solar radiation to generate energy in some form. Solar energy uses a renewable energy source and can become environmentally friendly in the future.

Benefits of solar energy:

- General availability and inexhaustibility of the source;
- In theory, 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, for example, lead, cadmium, gallium, arsenic, etc., and their production consumes a lot of other hazardous substances.

2. Wind power... This is a branch of energy that specializes 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 energy.

Wind energy prospects.

Wind power is a booming industry, as at the end of 2007 the total installed capacity of all wind turbines was 94.1 gigawatts, an increase of five times since 2000. Wind farms around the world in 2007 produced about 200 billion kWh, which is approximately 1.3% of global electricity consumption. Offshore wind farm Middelgrunden, near Copenhagen, Denmark. At the time of construction, it was the largest in the world.

Opportunities for the implementation of wind energy in Russia. In Russia, the possibilities of wind energy remain practically unrealized to date. A conservative attitude towards the future development of the fuel and energy complex practically impedes the effective introduction 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 power engineering. The sun is a natural fusion reactor. An even more interesting, albeit relatively distant, prospect is the use of nuclear fusion energy. Fusion 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 friendly.

Prospects for thermonuclear energy. This area of ​​energy has great potential, currently within the framework of the "ITER" project, in which Europe, China, Russia, the USA, South Korea and Japan are involved in France, the construction of the largest thermonuclear reactor is underway, the purpose of which is to bring out the CTS (Controlled Thermonuclear Fusion) to a new level. The construction is scheduled for completion in 2010.

4. Biofuel, biogas. Biofuel is a fuel from biological raw materials, obtained, as a rule, as a result of processing sugar cane stalks or rapeseed, corn, soybeans. A distinction is made between liquid biofuels (for internal combustion engines, eg ethanol, methanol, biodiesel) and gaseous (biogas, hydrogen).

Types of biofuels:

- Biomethanol
- Bioethanol
- Biobutanol
- Dimethyl ether
- Biodiesel
- Biogas
- Hydrogen

At the moment, the most developed are biodiesel and hydrogen.

5. Geothermal energy. Hidden under the volcanic islands of Japan are huge amounts of geothermal energy, which can be harnessed by extracting hot water and steam. Benefit: It emits about 20 times less carbon dioxide in electricity generation, which reduces its impact on the global environment.

6. The energy of waves, ebb and flow. In Japan, the most important source of energy is wave turbines, which convert the vertical movement of ocean waves into the air pressure that rotates the turbines of electric generators. A large number of tidal buoys have been installed on the coast of Japan. This is how the energy of the ocean is used to ensure the safety of ocean transport.

The huge potential of the Sun's 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, ebb and flow, geothermal energy, biogas, vegetable fuel, etc. All this leads to the conclusion that the possibilities of the considered so-called "reproducible" and relatively environmentally friendly energy resources are limited, at least in the relatively near future. Although the effect of their use in solving individual private problems of energy supply can already be quite impressive.

Of course, there is optimism about the possibilities of thermonuclear energy and other efficient methods of generating energy, intensively studied by science, but at the current scale of energy production. In the practical development of these possible sources, it will take several decades due to the high capital intensity and the corresponding inertia in the implementation of projects.

Research work of students:

1. Special report "Green Energy" for the future: “Japan is the world leader in solar power generation. 90% of the solar energy produced in Japan comes from solar panels in conventional homes. The Japanese government has set a target for 2010 to generate approximately 4.8 million kWh of energy from solar panels. Power generation from biomass in Japan. Methane gas is emitted from kitchen waste. The engine runs on this gas, which generates electricity, and also creates favorable conditions for the protection of the environment.

Modern heat and power systems industrial enterprises consist of three parts, on the efficiency of interaction of which the volume and efficiency of consumption of fuel and energy resources depend. 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 heating and electrical networks; consumers of energy resources.

Each of the participants 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 participants in the system are leveled by others, so that the total efficiency of the heat and power system turns out to be low. The most difficult is the stage of consumption of energy resources.

The level of use of fuel and energy resources in the domestic industry leaves much to be desired. A survey of enterprises in the petrochemical industry showed that the actual consumption of energy resources exceeds the theoretically required by about 1.7-2.6 times, i.e. targeted use of energy resources is about 43% of the real costs of production technologies. This situation is observed at the enterprises of the chemical, rubber-technical, food and industries, where thermal secondary resources are used insufficiently or ineffectively.

Heat fluxes that are not used in industrial heat engineering and heat power systems of an enterprise are mainly heat fluxes of liquids. (t< 90 0 С) и газов (t< 150 0 С) (см. табл. 1.8).

At present, quite effective designs are known that make it possible to use the heat of such parameters directly at an industrial facility. In connection with the increase in prices for energy resources, interest in them is growing, the production of heat exchangers and utilization thermal transformers is being established, which allows us to hope for an improvement in the near future with the use of such RES in industry.

As calculations of the efficiency of energy-saving measures show, each unit of thermal energy (1 J, 1 kcal) gives an equivalent saving of natural fuel fivefold. In those cases when it was possible to find the most successful solutions, the savings in natural fuel reached tenfold.

The main reason for this is the absence of intermediate stages of production, enrichment, transformation, transport of fuel energy resources to ensure the amount of saved energy resources. Capital investments in energy saving measures are 2-3 times lower than required capital investments into the extractive and related industries to obtain an equivalent amount of fossil fuel.

Within the framework of the traditionally established approach, the heat and power systems of large industrial consumers are considered in the only way - as a source of energy resources of the required quality in the right amount in accordance with the requirements of the technological regulations. The operating mode of heat and power systems is subject to the conditions dictated by the consumer. This approach usually leads to miscalculations in the selection of equipment and acceptance of effective solutions on the organization of heat technology and heat power systems, i.e. to a latent or obvious overspending of fuel and energy resources, which, naturally, affects the cost of production.

In particular, a fairly strong influence on general indicators the efficiency of energy consumption of industrial enterprises is influenced by seasonality. In the summer period, there is usually an excessive supply of VER heat technology and at the same time there are problems associated with an insufficient volume and quality of cooling heat carriers due to an increase in the temperature of the circulating water. In the period of low outside air 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 should 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 ER, and units, which, in turn, are sources of RES. The main tasks of industrial heat power engineering are:

ensuring the balance of energy resources of the required parameters at any time interval for reliable and economical operation of individual units and the production association as a whole; optimal choice of energy carriers in terms of thermophysical and thermodynamic parameters;

determination of the nomenclature and modes of operation of reserve and accumulating sources of energy resources, as well as alternative consumers of energy resources during the period of their excess supply; identification of reserves for the growth of energy efficiency of production at the current level of technical development and in the distant future.

In the future, TPPs PP 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, an external consumer or utilization energy installations that generate other types of energy resources.

Specific heat consumption for product output industrial production ranges from one to tens of gigajoules per ton of 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 efficiency of existing industries and not introducing significant changes in the operating mode of the main technological equipment. The most attractive is the organization of closed heat supply systems based on utilization plants, the enterprises of which have a high share of consumption of medium and low pressure steam and hot water.

The majority of 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 heat carrier in order to recover the discharged heat. This will allow connecting numerous sources and consumers within the entire enterprise or a dedicated subdivision and providing hot water with the required parameters of industrial and sanitary consumers.

Closed heat supply systems are one of the main elements of waste-free production systems. Regeneration of heat of low parameters and its transformation to the required temperature level can return a significant part of energy resources, which is usually discharged into the atmosphere directly or using recycling water supply systems.

V 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 discharged heat 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. Under such conditions, it is possible to organize utilization centralized or local heat pump systems, which make it possible to recover up to 70% of the heat expended 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. At present, the situation is changing and heat pump installations are beginning to be introduced into the systems of both heat supply for housing and communal services and industrial facilities.

One of the most effective solutions is the organization of utilization refrigeration systems based on absorption heat transformers (ATT). Industrial refrigeration systems are based on refrigeration units of the vapor compression type, and the consumption of electricity for the production of cold reaches 15-20% of its total consumption throughout the enterprise. Absorption heat transformers as alternative sources of refrigeration supply have several advantages, in particular:

low-grade heat of industrial water, flue gases or low pressure exhaust steam can be used to drive the ATT;

with the same composition of equipment, ATT is capable of operating both in the cold supply mode and in the heat pump mode for heat release.

Air and cold supply systems of an industrial enterprise do not have a significant effect on the supply of water energy resources and can be considered as heat consumers in the development of 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, one should expect a deterioration in the ecological situation associated with global overheating of the planet due to the intensification of "thermal pollution" - an increase in thermal emissions into the atmosphere.

Control questions and assignments to 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 separation and separation of reaction products in the production of ethylene?

2. Describe the input and output parts of the energy balance of the pyrolysis furnace. How did the organization of feed water heating affect them?

3. Describe the structure of energy consumption in the production of isoprene by the method of two-stage dehydrogenation. What is the share of cold and recycled water consumption in it?

4. Analyze the structure of the heat balance of synthetic ethyl alcohol production by direct ethylene hydration. List the items of the balance sheet expenditure that relate to heat energy losses.

5. Explain why TAC-based heating technology is classified as low temperature.

6. What characteristics make it possible 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 own needs.

8. Using the daily steam consumption schedule at a petrochemical plant, determine its maximum and minimum values ​​and compare them. Describe the monthly heat consumption schedule of a petrochemical plant.

9. What explains the unevenness annual charts thermal loads of industrial enterprises?

10. Compare the graphs of the annual loads of machine-building enterprises and chemical plants and formulate conclusions.

11. Should combustible production wastes always be considered as secondary energy resources?

12. Describe 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 of VER of combustion products sent to waste heat boilers.

14. What is the equivalent saving of fossil fuel given by the saving of a unit of heat at the stage of consumption and why?

15. Compare the volumes of the output of water energy resources in the production of butadiene by the method of two-stage dehydrogenation n-butane and by the method of contact decomposition of alcohol (see table. A.1.1).

Table P.l.l

Secondary energy resources of the petrochemical industry

To assess the prospects of TPPs, first of all, it is necessary to understand their advantages and disadvantages in comparison with other sources of electricity.

The benefits include the following.

• 1. Unlike hydroelectric power plants, thermal power plants can be located relatively freely, taking into account the fuel used. Gas-oil TPPs can be built anywhere, since transportation of gas and fuel oil is relatively cheap (compared to coal). It is advisable to locate pulverized coal thermal power plants near sources of coal mining. By now, the "coal" heat power industry has developed and has a pronounced regional character.
• 2. The specific cost of installed capacity (cost of 1 kW of installed capacity) and the construction period for TPPs are much shorter than for NPPs and HPPs.
• 3. Electricity production at TPPs, in contrast to 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 lands for TPPs are significantly less than for NPPs, and, of course, they cannot be compared with hydroelectric power plants, the impact of which on the environment may have a far from regional character. Examples are the cascades of hydroelectric power plants on the river. Volga and Dnieper.
• 5. At TPPs, you can burn almost any fuel, including the lowest-grade coals, ballasted with ash, water, rock.
• 6. Unlike nuclear power plants, there are no problems with the utilization of TPPs at the end of their service life. As a rule, the infrastructure of a TPP 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 funds, serve for a long time. Most of the TPPs built over 80 years according to the GOELRO plan are still in operation and will continue to work after the installation of new, more advanced turbines and boilers on them.

Along with these advantages, TPP 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. True, to say that nuclear power plants that do not have constant emissions into the atmosphere, but create a constant threat of radioactive pollution and have problems with the storage and processing of spent nuclear fuel, as well as the disposal of the nuclear power plant itself after the end of its service life, or hydroelectric power plants that flood huge areas of economic land and change regional climate, are ecologically more "clean" is possible only with a significant degree of convention.
• 2. Traditional TPPs have a relatively low efficiency (better than that of a nuclear power plant, but much worse than that of a CCGT unit).
• 3. Unlike hydroelectric power plants, thermal power plants hardly participate in covering the variable part of the daily electric load schedule.
• 4. TPPs are significantly dependent on the supply of fuel, often imported.

Despite all these shortcomings, TPPs 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 fossil fuel used. Despite the great advantages of liquid fuel (oil, fuel oil) as an energy carrier (high calorific value, ease of transportation), its use at TPPs will increasingly decrease, 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 great importance. Therefore, liquid fuel (fuel oil) at TPPs will be used either as a backup fuel at gas-oil TPPs, or as an auxiliary fuel at pulverized coal TPPs, which ensures stable combustion of coal dust in a boiler under certain operating conditions.

The use of natural gas at condensing steam-turbine TPPs is irrational: for this, it is necessary to use steam-gas utilization units, which are based on high-temperature gas turbine units.

Thus, the long-term prospect of using classic steam turbine TPPs both in Russia and abroad is primarily associated with the use of coals, especially low-grade ones. This, of course, does not mean the termination of the operation of gas-oil thermal power plants, which will be gradually replaced by steam turbines.

Negative environmental and social impacts of construction large hydropower plants make us look closely at their possible place in the electric power industry of the future.

The future of hydropower

Large hydroelectric power plants perform the following functions in the power system:

1. power generation;
2. fast matching of the generation power with the power consumption, frequency stabilization in the power system;
3. accumulation and storage of energy in the form of potential energy of water in the gravitational field of the Earth with conversion into electricity at any time.

Power generation and power maneuvers are possible at any scale HPP. And the accumulation of energy for a period from several months to several years (for winter and dry years) requires the creation of large reservoirs.

For comparison, a 12-kg, 12-volt, 85-amp-hour car battery can store 1.02 kilowatt-hours (3.67 MJ). To store such an amount of energy and convert it into electricity in a hydroelectric unit with an efficiency of 0.92, you need to raise 4 tons (4 cubic meters) of water to a height of 100 m or 40 tons of water to a height of 10 m.

In order for a hydroelectric power station with a capacity of only 1 MW to operate on stored water 5 months a year for 6 hours a day on stored water, it is necessary to accumulate at an altitude of 100 m and then run through a turbine 3.6 million tons of water. With a reservoir area of ​​1 sq. Km, the level will decrease by 3.6 m. The same volume of production at a diesel power plant with an efficiency of 40% will require 324 tons of diesel fuel. Thus, in cold climates, storing water energy for the winter requires high dams and large reservoirs.

In addition, on b O In the most part of the territory of Russia in the permafrost zone, small and medium-sized rivers freeze to the bottom in winter. In these parts, small hydroelectric power plants are useless in winter.

Large hydroelectric power plants are inevitably located at a considerable distance from many consumers, and the costs of building power lines and energy losses and heating wires should be taken into account. So, for the Transsiberian (Shilkinskaya) hydroelectric power station, the cost of building a transmission line-220 to Transsib with a length of only 195 km (very little for such a construction) exceeds 10% of all costs. The costs of building power transmission networks are so significant that in China the capacity of wind turbines, which have not yet been connected to the grid, exceeds the capacity of the entire energy sector in Russia east of Lake Baikal.

Thus, the prospects for hydropower depend on advances in technology and production, and storage and transmission of energy collectively.

Energy is a very capital intensive and therefore conservative industry. Some power plants are still in operation, especially hydroelectric power plants built at the beginning of the twentieth century. Therefore, to assess the prospects for half a century, instead of volumetric indicators of one or another type of energy, it is more important to look at the speed of progress in each technology. Suitable indicators of technical progress in generation are efficiency (or percentage of losses), unit capacity of units, cost of 1 kilowatt of generation power, cost of transmission of 1 kilowatt per 1 km, cost of storing 1 kilowatt-hour per day.

Energy storage

Storage electricity is a new industry in the energy sector. For a long time, people stored fuel (firewood, coal, then oil and oil products in tanks, gas in pressurized tanks and underground storage facilities). Then mechanical energy storage devices appeared (raised water, compressed air, super flywheels, etc.), among them pumped storage power plants remain the leader.

Outside the permafrost zones, the heat accumulated by solar water heaters can already be pumped underground to heat houses in winter. After the collapse of the USSR, experiments on the use of solar heat energy for chemical transformations ceased.

Known chemical batteries have a limited number of charge-discharge cycles. Supercapacitors have much more O longer durability, but their capacity is still insufficient. The accumulators of magnetic field energy in superconducting coils are being improved very quickly.

A breakthrough in the distribution of energy storage will occur when the price drops to $ 1 per kilowatt-hour. This will make it possible to widely use types of power generation that are not capable of operating continuously (solar, wind, tidal energy).

alternative energy

From technology generating the fastest change is happening now in solar energy. Solar panels make it possible to produce energy in any required amount - from charging a phone to supplying megacities. The energy of the Sun on Earth is a hundred times more than other types of energy combined.

Wind farms have gone through a period of price declines and are at the stage of increasing tower size and generating capacity. In 2012, the capacity of all wind turbines in the world surpassed the capacity of all power plants in the USSR. However, in the 20s of the 21st century, the possibilities for improving wind turbines will be exhausted and solar energy will remain the engine of growth.

The technology of large hydroelectric power plants has passed its "finest hour"; every decade, large hydroelectric power plants are being built less and less. The attention of inventors and engineers turns to tidal and wave power plants. However, tides and large waves are not everywhere, so their role will be insignificant. Small hydroelectric power plants will still be built in the 21st century, especially in Asia.

Getting electricity from the heat coming from the bowels of the Earth (geothermal energy) is promising, but only in certain areas. Fossil fuel combustion technologies will compete with solar and wind energy for several decades, especially where there is little wind and sun.

The fastest improving technologies for producing combustible gas by fermentation of waste, pyrolysis or decomposition in plasma). However, solid household waste always before gasification will require sorting (or better separate collection).

TPP technologies

The efficiency of combined cycle power plants exceeded 60%. Re-equipment of all gas-fired CHPPs into steam-gas (more precisely, gas-steam) will increase electricity generation by more than 50% without increasing gas combustion.

Coal-fired and fuel oil CHPPs are much worse than gas-fired ones in terms of efficiency, the price of equipment, and the amount of harmful emissions. In addition, coal mining requires the most human lives per megawatt hour of electricity. Gasification of coal will prolong the existence of the coal industry for several decades, but the miner's profession is unlikely to survive until the 22nd century. It is very likely that steam and gas turbines will be replaced by rapidly improving fuel cells in which chemical energy is converted into electrical energy bypassing the stages of obtaining thermal and mechanical energy. In the meantime, fuel cells are very expensive.

Nuclear power

The efficiency of nuclear power plants has grown the most slowly over the past 30 years. Improvements to nuclear reactors, each costing several billion dollars, are very slow, and safety requirements are driving up construction costs. The "nuclear renaissance" did not take place. Since 2006, the commissioning of nuclear power plants in the world is less than not only the commissioning of wind farms, but also solar ones. Nevertheless, it is likely that some nuclear power plants will survive until the 22nd century, although due to the problem of radioactive waste, their end is inevitable. Probably, thermonuclear reactors will work in the 21st century, but their small number, of course, "will not make the weather."

Until now, the possibility of realizing a "cold fusion" remains unclear. In principle, the possibility of a thermonuclear reaction without ultra-high temperatures and without the formation of radioactive waste does not contradict the laws of physics. But the prospects for obtaining cheap energy in this way are very dubious.

New technologies

And a little fantasy in the drawings. Now in Russia three new principles of isothermal conversion of heat into electricity are being tested. These experiments have a lot of skeptics: after all, the second law of thermodynamics is violated. So far, one tenth of a microwatt has been received. If successful, the clock and instrument batteries will appear first. Then light bulbs without wires. Each light bulb will be a source of coolness. Air conditioners will generate electricity instead of consuming it. The wires in the house will no longer be needed. It's too early to judge when science fiction comes true.

In the meantime, we need the wires. More than half of the price of a kilowatt-hour in Russia is accounted for by the cost of building and maintaining power lines and substations. More than 10% of the generated electricity goes to heating wires. Reducing costs and losses allows "smart grids", which automatically manage many consumers and producers of energy. In many cases, it is better to transfer direct current than alternating current to reduce losses. In general, heating wires can be avoided by making them superconducting. However, superconductors operating at room temperature have not been found and it is not known whether they will be found.

For sparsely populated areas with high transportation costs, the prevalence and availability of energy sources is also important.

The most common energy is from the Sun, but the Sun is not always visible (especially beyond the Arctic Circle). But in winter and at night the wind often blows, but not always and not everywhere. Nevertheless, wind-solar power plants already now allow to significantly reduce the consumption of diesel fuel in remote villages.

Some geologists claim that oil and gas are formed almost everywhere today from carbon dioxide that enters the ground with water. However, the use of hydraulic fracturing ("fracking") destroys natural places where oil and gas can accumulate. If this is true, then a small amount of oil and gas (ten times less than now) can be extracted almost everywhere without damage to the geochemical circulation of carbon, but exporting hydrocarbons means depriving yourself of the future.

Diversity natural resources in the world means that sustainable power generation requires a combination of different technologies applicable to local conditions. In any case, an unlimited amount of energy on Earth cannot be obtained for both environmental and resource reasons. Therefore, the growth in the production of electricity, steel, nickel and other material things on Earth in the next century will inevitably be replaced by an increase in the production of intellectual and spiritual.

Igor Eduardovich Shkradyuk

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1. Prospects for the development of heat power

Humanity satisfies about 80% of its energy needs through fossil fuels: oil, coal, natural gas. Their share in the balance of the electric power industry is slightly lower - about 65% (39% - coal, 16% - natural gas, 9% - liquid fuels).

According to the forecasts of the International Energy Agency, by 2020, with an increase in primary energy consumption by 35%, the share of fossil fuels will increase to more than 90%.

Today, the demand for oil and natural gas is met for 50-70 years. However, despite the constant growth in production, these periods have not decreased in the last 20-30 years, but are growing as a result of the discovery of new fields and the improvement of production technologies. As for coal, its recoverable reserves will last more than 200 years.

Thus, there is no question of fossil fuel shortages. The point is to use them in the most rational way to improve people's living standards while unconditionally preserving their environment. This fully applies to the electric power industry.

In our country, the main fuel for thermal power plants is natural gas. In the foreseeable future, its share will, apparently, decrease, however, the absolute consumption of power plants will remain approximately constant and rather large. For many reasons - not always sensible - it is not being used effectively enough.

Natural gas consumers are traditional steam turbine TPPs and CHPPs, mainly with steam pressures of 13 and 24 MPa (their efficiency in condensing mode is 36-41%), but also old CHPPs with significantly lower parameters and high production costs.

It is possible to significantly increase the efficiency of gas use when using gas turbine and combined cycle technologies.

The maximum unit capacity of the GTU has reached 300 MW by now, the efficiency at autonomous work- 36-38%, and in multi-shaft gas turbines based on aircraft engines with high pressure ratios - 40% or more, the initial gas temperature is 1300-1500 ° C, the compression ratio is 20-30.

To ensure the practical success of reliability, thermal efficiency, low unit cost and operating costs, today power gas turbines are designed according to the simplest cycle, at the maximum achievable gas temperature (it is constantly growing), with pressure ratios close to the optimal ones in terms of specific work and efficiency of combined plants. which use the heat of the exhaust gases in the turbine. The compressor and turbine are located on the same shaft. Turbo-machines form a compact block with an integrated combustion chamber: annular or block-annular. The zone of high temperatures and pressure is localized in a small space, the number of parts that receive them is small, and these parts themselves are carefully worked out. These principles are the result of many years of design evolution.

Most of the GTU with a capacity of less than 25-30 MW is created on the basis or by the type of aircraft or marine gas turbine engines (GTE), which are characterized by the absence of horizontal connectors and the assembly of casings and rotors using vertical connectors, widespread use of rolling bearings, small weight and dimensions. The service life and availability indicators required for ground and power plant operation are provided in aircraft structures with acceptable costs.

With a capacity of more than 50 MW, the GTU is designed specifically for power plants, and is performed as single-shaft, with moderate compression ratios and a sufficiently high exhaust gas temperature, which facilitates the use of their heat. To reduce the size and cost and increase the efficiency, GTUs with a capacity of 50-80 MW are performed as high-speed ones with an electric generator driven through a gearbox. Typically, such gas turbines are aerodynamically and structurally similar to more powerful units designed for direct drive of electric generators with a rotational speed of 3600 and 3000 rpm. This simulation improves reliability and reduces development and deployment costs.

Cycle air is the main coolant in the gas turbine unit. Air cooling systems are implemented in nozzle and rotor blades, using technologies that provide the required properties at an acceptable cost. The use of steam or water for cooling turbines can improve the performance of GTU and STU with the same cycle parameters or provide a further increase in comparison with air to the initial temperature of gases. Although the technical foundations for using cooling systems with these coolants are far from being as detailed as with air, their implementation is becoming a practical issue.

The gas turbine plant has mastered the "low-toxic" combustion of natural gas. It is most effective in combustion chambers operating on a previously prepared homogeneous mixture of gas with air at large (a = 2-2.1) excess air and with a uniform and relatively low (1500-1550 ° C) torch temperature. With such an organization of combustion, the formation of NOX can be limited to 20-50 mg / m3 under normal conditions (as a standard, they refer to combustion products containing 15% oxygen) with a high completeness of combustion (concentration of CO<50 мг/м3). Проблема заключается в сохранении устойчивости горения и близких к оптимальным условий горения при изменениях режимов. С разной эффективностью это достигается ступенчатой подачей топлива (включением/отключением тех или иных горелок или зон горения), регулированием расхода поступающего на горение воздуха и дежурным диффузионным факелом небольшой мощности.

It is much more difficult to reproduce a similar technology of "low-toxic" combustion on liquid fuel. However, there are certain successes here as well.

Of great importance for the progress of stationary gas turbines is the choice of materials and shaping technologies that ensure long service life, reliability and moderate cost of their parts.

Parts of the turbine and combustion chamber, which are washed by high-temperature gases containing components that can cause oxidation or corrosion, and are exposed to high mechanical and thermal stresses, are made of complex alloyed nickel-based alloys. The blades are intensively cooled and are made with complex internal paths using the precision casting method, which allows using materials and obtaining the shapes of parts that are impossible with other technologies. In recent years, casting of blades with directional and single crystallization has been increasingly used, which makes it possible to noticeably improve their mechanical properties.

The surfaces of the hottest parts are protected with coatings that prevent corrosion and lower the temperature of the base metal.

The simplicity and small size of even powerful gas turbines and their auxiliary equipment make it technically possible to supply them with large, factory-made blocks with auxiliary equipment, pipeline and cable connections, tested and adjusted for normal operation. When installed outside a building, a casing (casing) is a component of each unit, which protects the equipment from bad weather and reduces sound emissions. The blocks are installed on flat foundations and docked. The space under the cladding is ventilated.

The power industry in Russia has a long-term, albeit ambiguous, experience in operating a gas turbine unit with a unit capacity of 2.5 to 100 MW. A good example is the gas turbine CHP, which has been operating for more than 25 years in the harsh climatic conditions of Yakutsk, in an isolated power system with an uneven load.

Currently, gas turbines are operated at power plants in Russia, which are noticeably inferior to foreign ones in terms of their parameters and indicators. To create modern power gas turbines, it is advisable to combine the efforts of power engineering and aircraft engine enterprises based on aviation technology.

A 110 MW power plant has already been manufactured and is being tested, produced by the defense enterprises Mash-Proekt (Nikolaev, Ukraine) and Saturn (Rybinsk Motors), which has quite modern performance.

Various standard sizes of medium-power gas turbines have been created in the country on the basis of aircraft or marine engines. Several units GTD-16 and GTD-25 "Mashinproekt", GTU-12 and GTU-16P of Perm "Aviadvigatel", AL-31ST "Saturn" and NK-36 "NK Engines" compressor stations of main gas pipelines. For many years, hundreds of earlier GTUs of the Trud (now NK Engines) and Mashproekt enterprises have been operating there. There is a rich and, in general, positive experience of operation at power plants of the 12 MW Mashproekt GTU, which served as the basis for more powerful PT-15.

In modern high-power gas turbine plants, the temperature of the exhaust gases in the turbine is 550-640 ° C. Their heat can be used for heat supply or utilized in the steam cycle, with an increase in the efficiency of the combined steam-gas plant up to 55-58%, actually obtained already at the present time. Various combinations of gas turbine and steam turbine cycles are possible and practically applied. Among them, binary ones dominate, with the supply of all heat in the combustion chamber of the GTU, the generation of high-parameter steam in the waste heat boiler behind the GTU and its use in the steam turbine.

The first binary-type PTU in our country has been operating at the North-West TPP of St. Petersburg for about 2 years. Its capacity is 450 MW. The CCGT unit includes two V94.2 gas turbines developed by Siemens, supplied by its joint venture with LMZ, Interturbo, 2 waste-heat boilers and one steam turbine. The supply of a block ACS for the CCGT unit was carried out by a consortium of Western firms. All the rest of the main and auxiliary equipment was supplied by domestic enterprises.

By 01.09.02, the CCGT unit operated in the condensation mode for 7200 hours while operating in the mode in the control range (300-450 MW) with an average efficiency of 48-49%; its calculated efficiency is 51%.

In a similar CCGT unit with the domestic GTE-110, it is possible to obtain even a slightly higher efficiency.

Even higher efficiency, as can be seen from the same table, will ensure the use of the currently designed GTE-180.

With the use of the currently designed GTUs, it is possible to achieve significantly higher indicators, not only in new construction, but also in the technical re-equipment of existing TPPs. It is important that with technical re-equipment with the preservation of the infrastructure and a significant part of the equipment and the implementation of binary CCGT units on them, it is possible to achieve close to optimal efficiency values ​​with a significant increase in the power of power plants.

The amount of steam that can be generated in the waste heat boiler installed behind the GTP-180 is close to the throughput of one exhaust of the K-300 steam turbine. Depending on the number of exhausts retained during those rearmament, it is possible to use 1, 2 or 3 GTE-180. To avoid exhaust overload at low ambient temperatures, it is advisable to use a three-circuit scheme of the steam section with reheating of steam, in which the greater power of the CCGT unit is achieved at a lower steam flow rate into the condenser.

While keeping all three exhausts, a CCGT with a capacity of about 800 MW is placed in a cell of two neighboring power units: one steam turbine remains, and the other is dismantled.

The specific cost of those re-equipment in the CCGT cycle will be 1.5 times or more cheaper than new construction.

Similar solutions are advisable for those re-equipment of gas-and-fuel GRES with power units of 150 and 200 MW. Less powerful GTE-110 can be widely used on them.

For economic reasons, in the first place, CHP plants need technical re-equipment. For them, the most attractive binary CCGT units of this type, as at the North-West CHPP of St. Petersburg, allow to dramatically increase the generation of electricity for thermal consumption and change the ratio between electrical and heat load within wide limits, while maintaining an overall high fuel utilization factor. The module worked out at the Severo-Zapadnaya CHPP: GTU - waste heat boiler generating 240 t / h of steam, can be directly used to power turbines PT-60, PT-80 and T-100.

With a full load of their exhausts, the mass flow rate of steam through the first stages of these turbines will be significantly lower than the nominal one and it will be possible to pass it at the reduced pressures characteristic of CCGT-450. This, as well as a decrease in the temperature of live steam to less than 500-510 ° C, will remove the question of the exhaustion of the resource of these turbines. Although this will be accompanied by a decrease in the capacity of steam turbines, the total capacity of the unit will more than double, and its power generation efficiency will, regardless of the mode (heat supply), be significantly higher than that of the best condensing power units.

Such a change in indicators radically affects the efficiency of CHP plants. The total costs of generating electricity and heat will decrease, and the competitiveness of CHP plants in the markets of both types of products - as evidenced by financial and economic calculations - will increase.

At power plants, in the fuel balance of which there is a large share of fuel oil or coal, but there is also natural gas, in an amount sufficient to power a gas turbine unit, thermodynamically less efficient gas turbine superstructures may be advisable.

For the domestic thermal power industry, the most important economic task is the development and widespread use of gas turbine plants with the parameters and indicators that have already been achieved in the world. The most important scientific task is to ensure the design, manufacture and successful operation of these gas turbines.

Of course, there are still many opportunities for the further development of GTU and CCGT units and an increase in their performance. CCPs with an efficiency of 60% have been designed abroad and the task is to increase it in the foreseeable future to 61.5-62%. To this end, instead of cyclic air, steam is used as a cooler in the gas turbine unit, and a closer integration of the gas turbine and steam cycles is carried out.

Even greater opportunities are opened up by the creation of "hybrid" installations in which a gas turbine (or CCGT) is built on top of a fuel cell.

High-temperature fuel cells (FCs), solid oxide or based on molten carbonates, operating at temperatures of 850 and 650 ° C, serve as heat sources for the gas turbine and steam cycle. Specific projects with a capacity of about 20 MW - mainly in the United States - have calculated efficiencies of 70%.

These units are designed to operate on natural gas with an internal reformer. It is possible, of course, to run them on synthesis gas or pure hydrogen obtained from coal gasification, and to create complexes in which coal processing is integrated into the technological cycle.

The existing programs set the task of increasing the capacity of hybrid plants up to 300 MW and more in the future, and their efficiency - up to 75% on natural gas and 60% on coal.

The second most important fuel for the power industry is coal. In Russia, the most productive coal deposits - Kuznetsk and Kansko-Achinsk - are located in the south of central Siberia. The coals of these deposits are low-sulfur. The cost of their extraction is low. However, the area of ​​their application is currently limited due to the high cost of rail transportation. In the European part of Russia, in the Urals and the Far East, transport costs exceed the cost of extracting Kuznetsk coal by 1.5-2.5 times, and Kansk-Achinsk coal - by 5.5-7.0 times.

In the European part of Russia, coal is mined by a mine method. Basically, these are coal from Pechora, anthracites of the Southern Donbass (power engineers get their screenings - shtyb) and brown coals of the Moscow region. All of them are high-ash and sulphurous. Due to natural conditions (geological or climatic), the cost of their production is high, and competitiveness when used in power plants is difficult to ensure, especially with the inevitable tightening of environmental requirements and the development of a steam coal market in Russia.

Currently, TPPs use coals that differ greatly in quality: more than 25% of their total consumption has an ash content of more than 40%; 18.8% - calorific value below 3000 kcal / kg; 6.8 million tons of coal - sulfur content over 3.0%. The total amount of ballast in coal is 55 million tons per year, including rock - 27.9 million tons and moisture - 27.1 million tons. As a result, it is very important to improve the quality of steam coal.

The prospect of using coal in the Russian electric power industry will be determined by the state policy of prices for natural gas and coal. In recent years, there has been an absurd situation when gas in many regions of Russia is cheaper than coal. It can be assumed that gas prices will grow faster and will become higher than coal prices in a few years.

To expand the use of the Kuznetsk and Kansk-Achinsk coals, it is advisable to create preferential conditions for their rail transportation and develop alternative methods for transporting coal: by water, through pipelines, in an enriched state, etc.

For strategic reasons, in the European part of Russia it is necessary to maintain the production of a certain amount of thermal coal of the best quality and in the most productive mines, even if this requires state subsidies.

The use of coal in power plants in conventional steam power units is commercially viable today and will be efficient for the foreseeable future. gas turbine power industry russia coal

In Russia, coal is burned at condensing power plants equipped with power units of 150, 200, 300, 500 and 800 MW, and at thermal power plants with boilers with a capacity of up to 1000 t / h.

Despite the low quality of coals and the instability of their characteristics during delivery, high technical, economic and operational indicators were achieved on domestic coal blocks soon after their development.

Large boilers use coal dust flaring, mainly with solid ash removal. Mechanical underburning does not exceed, as a rule, 1-1.5% when burning hard coal and 0.5% - brown coal. It increases to q4<4% при использовании низко реакционных тощих углей и антрацитового штыба в котлах с жидким шлакоудалением. Расчетные значения КПД брутто пылеугольных котлов составляют 90-92,5%. При длительной эксплуатации они на 1-2% ниже из-за увеличенных присосов воздуха в газовый тракт, загрязнения и шлакования поверхностей нагрева, ухудшения качества угля. Имеются реальные возможности значительного улучшения КПД котлов.

In recent years, coal blocks have been operating in an alternating mode with deep unloading or overnight shutdowns. A high, close to nominal, efficiency remains on them at unloading up to N3JI = 0.4 - = - 0.5 NH0M.

The situation is worse with respect to environmental protection. At Russian coal-fired TPPs there are no operating systems for flue gas desulfurization, there are no catalytic systems for their removal of NOX. The electrostatic precipitators installed for ash collection are not efficient enough; On boilers with a capacity of up to 640 t / h, various even less efficient cyclones and wet apparatus are widely used.

Meanwhile, for the future of thermal power engineering, its harmonization with the environment is of paramount importance. It is most difficult to achieve when using coal as a fuel, which contains an incombustible mineral part and organic compounds of sulfur, nitrogen and other elements that form substances harmful to nature, people or structures after coal combustion.

At the local and regional levels, the main air pollutants whose emissions are regulated are gaseous oxides of sulfur and nitrogen and particulate matter (ash). Their limitation requires special attention and costs.

One way or another, emissions of volatile organic compounds (the most severe pollutants, in particular benzopyrene), heavy metals (for example, mercury, vanadium, nickel) and polluted wastewater into water bodies are also controlled.

When rationing emissions from thermal power plants, the state limits them to a level that does not cause irreversible changes in the environment or human health that can negatively affect the living conditions of current and future generations. Determination of this level is associated with many uncertainties and depends to a large extent on technical and economic possibilities, since unreasonably strict requirements can lead to increased costs and worsen the economic situation of the country.

With the development of technology and the strengthening of the economy, the possibilities for reducing emissions from TPPs are expanding. Therefore, it is legitimate to speak (and strive!) To the minimum technically and economically conceivable impact of TPPs on the environment and to go for this at increased costs, however, those at which the competitiveness of TPPs is still ensured. Something similar is being done now in many developed countries.

Let's return, however, to traditional coal-fired power plants.

Of course, relatively inexpensive mastered and effective electric and fabric filters for radical dedusting of flue gases emitted into the atmosphere should be used first of all. Difficulties with electrostatic precipitators typical for the Russian energy sector can be eliminated by optimizing their size and design, improving power systems using pre-ionization and alternating, intermittent or pulsed power supply devices, and automating the filter operation control. In many cases, it is advisable to reduce the temperature of the gases entering the electrostatic precipitator.

To reduce emissions of nitrogen oxides into the atmosphere, technological measures are primarily used. They consist in influencing the combustion process by changing the design and operating modes of burners and combustion devices and creating conditions under which the formation of nitrogen oxides is small or impossible.

In boilers operating on Kansk-Achinsk coals, to reduce the formation of nitrogen oxides, it is advisable to use the proven principle of low-temperature combustion. With three stages of fuel supply, the excess air ratio in the active combustion zone will be 1.0-1.05. An excess of oxidant in this zone in the presence of intensive mass transfer in the volume will provide a low rate of slagging. So that the withdrawal of part of the air from the active combustion zone does not increase the temperature of the gases in its volume, a replacement amount of recirculation gases is supplied to the torch. With such an organization of combustion, it is possible to reduce the concentration of nitrogen oxides to 200-250 mg / m3 at the rated load of the power unit.

To reduce nitrogen oxide emissions, SibVTI is developing a system for heating coal dust before combustion, which will reduce NOX emissions to less than 200 mg / m3.

When using Kuznetsk hard coal on 300-500 MW units, low-toxic burners and staged fuel combustion should be used to reduce the formation of NOX. The combination of these measures can provide NOX emissions<350 мг/м3.

It is especially difficult to reduce the formation of NOX during the combustion of low-reactive fuel (ASh and Kuznetskiy lean) in boilers with liquid bottom ash removal. At present, such boilers have NOX concentrations of 1200-1500 mg / m3. If natural gas is available at power plants, it is advisable to organize a three-stage combustion with NOX reduction in the upper part of the furnace (rebenning process). In this case, the main burners are operated with an excess air ratio of agor = 1.0-1.1, and natural gas is supplied to the furnace together with a drying agent to create a reduction zone. This combustion scheme can provide NOX concentrations up to 500-700 mg / m3.

Chemical methods are used to remove nitrogen oxides from flue gases. Two nitrogen-cleaning technologies are industrially used: selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) of nitrogen oxides.

With a higher efficiency of SCR technology, the specific capital costs in it are an order of magnitude higher than in SNCR. On the contrary, the consumption of the reducing agent, most often ammonia, with SCR technology is 2-3 times lower due to the higher selectivity of the use of ammonia in comparison with SNCR.

SNKV-technology, tested at a boiler with a capacity of 420 t / h of the Togliatti CHPP, can be used in the technical re-equipment of coal-fired power plants with boilers operating with liquid bottom ash removal. This will provide them with a NOX emission level of 300-350 mg / m3. In ecologically stressed areas, SCR technology can be used to achieve NOX emissions of about 200 mg / m3. In all cases, the use of nitrogen purification should be preceded by technological measures to reduce the formation of NOX.

With the help of currently mastered technologies, it is possible to economically clean the combustion products of sulfurous fuel with the capture of 95-97% SO2. In this case, natural limestone is usually used as a sorbent; commercial gypsum is a by-product of cleaning.

In our country, at the Dorogobuzhskaya GRES, an installation with a capacity of 500-103 nm3 / h was developed and industrially operated, which implements the ammonia-sulfate desulfurization technology, in which the sorbent is ammonia, and the by-product is commercial ammonium sulfate, which is a valuable fertilizer.

Under the current Russian standards, binding of 90-95% SO2 is necessary when using fuel with a reduced sulfur content S> 0.15% kg / MJ. When burning low and medium sulfurous fuel S< 0,05% кг/МДж целесообразно использовать менее капиталоемкие технологии.

The following are currently considered as the main directions for further increasing the efficiency of coal-fired TPPs:

increase in steam parameters in comparison with the mastered 24 MPa, 540/540 ° С with simultaneous improvement of equipment and systems of steam power plants;

development and improvement of promising coal-fired CCGT units;

improvement and development of new flue gas cleaning systems.

Comprehensive improvement of the schemes and equipment made it possible to increase the efficiency of supercritical coal-fired power units from about 40 to 43-43.5% without changing the steam parameters. Increasing the parameters from 24 MPa 545/540 ° C to 29 MPa, 600/620 ° C increases the efficiency in real projects on coal to about 47%. The rise in the cost of power plants with large (600-800 MW) units due to the use of more expensive materials (for example, austenitic superheater tubes) at higher parameters is relatively small. It is 2.5% with an increase in efficiency from 43 to 45% and 5.5 to 47%. However, even this rise in price pays off at very high coal prices.

Work on the super critical parameters of steam, which began in the middle of the last century in the USA and the USSR, has been commercialized in recent years in Japan and Western European countries with high energy prices.

In Denmark and Japan, power units with a capacity of 380-1050 MW with a live steam pressure of 24-30 MPa and superheating up to 580-610 ° C have been built and are successfully operating on coal. Among them there are blocks with double reheat up to 580 ° С. The efficiency of the best Japanese units is at the level of 45-46%, the Danish ones, operating on cold circulating water with a deep vacuum, are 2-3% higher.

Lignite power units with a capacity of 800-1000 MW with steam parameters up to 27 MPa, 580/600 ° C and an efficiency of up to 45% have been built in Germany.

Work on a power unit with super critical steam parameters (30 MPa, 600/600 ° C), organized in our country, confirmed the reality of creating such a unit with a capacity of 300-525 MW with an efficiency of about 46% in the coming years.

An increase in efficiency is achieved not only by increasing steam parameters (their contribution is about 5%), but also, to a greater extent, due to an increase in the efficiency of the turbine (4.5%) and boiler (2.5%) and improvement of station equipment with a decrease in losses characteristic of his work.

The backlog available in our country was focused on the steam temperature of 650 ° C and the widespread use of austenitic steels. A small experimental boiler with such parameters and a steam pressure of 30.0 MPa has been operating since 1949 at the VTI experimental CHPP for over 200 thousand hours. It is in working order and can be used for research purposes and long-term tests. SKR-100 power unit at Kashirskaya SDPP with a 720 t / h boiler and a 30 MPa / 650 ° C turbine

worked in 1969 over 30 thousand hours. After the termination of operation for reasons not related to its equipment, it was mothballed. In 1955, K. Rakov at VTI worked out the possibilities of creating a boiler with steam parameters of 30 MPa / 700 ° C.

The use of austenitic steels with high coefficients of linear expansion and low thermal conductivity for the manufacture of massive unheated parts: steam lines, rotors and turbine casings and fittings causes obvious difficulties in the case of cyclic loads inevitable for power equipment. With this in mind, nickel-based alloys that can operate at significantly higher temperatures may be more practical in practice.

So in the USA, where, after a long break, work has been resumed aimed at introducing super critical parameters of steam, they concentrate mainly on the development and testing of the materials necessary for this.

For parts operating at the highest pressures and temperatures: superheater tubes, collectors, main steam lines, several nickel-based alloys have been selected. For the reheating path, where the pressures are significantly lower, austenitic steels are also considered, and for temperatures below 650 ° C - promising ferritic steels.

During 2003, it is planned to identify improved alloys, manufacturing processes and coating methods that ensure the operation of power boilers at steam temperatures up to 760 ° C, taking into account the characteristic sweeps, temperature changes and possible corrosion in the environment of real coal combustion products.

It is also planned to adjust the ASME calculation standards for new materials and processes and to consider the design and operation of equipment at steam temperatures up to 870 ° C and pressures up to 35 MPa.

In the countries of the European Union, on the basis of cooperative financing, an improved coal-fired power unit with a maximum steam temperature above 700 ° C is being developed with the participation of a large group of energy and machine-building companies. The parameters of live steam are accepted for it

37.5 MPa / 700 ° C and a cycle with double reheat up to 720 ° C at pressures of 12 and 2.35 MPa. At a pressure in the condenser of 1.5-2.1 kPa, the efficiency of such a unit should be above 50% and can reach 53-54%. And here the materials are critical. They are designed to provide a long-term strength for 100 thousand hours, equal to 100 MPa at temperatures:

nickel-based alloys for pipes of the last bundles of superheaters, outlet headers, steam pipelines, casings and turbine rotors - 750 ° C;

austenitic steels for superheaters - 700 ° C;

ferritic-martensitic steels for boiler pipes and collectors - 650 ° С.

New designs of boilers and turbines, manufacturing technologies (for example, welding) and new close layouts are being worked out in order to reduce the need for the most expensive materials and the unit cost of units without reducing the reliability and performance indicators typical of modern steam power units.

The implementation of the unit is scheduled after 2010, and the ultimate goal in another 20 years is to achieve a net efficiency of up to 55% at steam temperatures up to 800 ° C.

Despite the already achieved successes and the existing prospects for further improvement of steam power units, the thermodynamic benefits of combined plants are so great that much attention is paid to the development of coal-fired CCGT units.

Since the combustion of ash-containing fuel in the gas turbine unit is difficult due to the formation of deposits in the flow path of the turbines and the corrosion of their parts, work on the use of coal in the gas turbine unit is carried out mainly in two directions:

gasification under pressure, purification of combustible gas and its combustion in a gas turbine unit; the gasification unit is integrated with the CCGT unit, the cycle and scheme of which are the same as for natural gas;

direct combustion of coal under pressure in a high-pressure fluidized bed steam generator, purification and expansion of combustion products in a gas turbine.

The implementation of the processes of gasification and purification of artificial gas from coal ash and sulfur compounds at high pressures makes it possible to increase their intensity, reduce the size and cost of equipment. The heat removed during gasification is utilized within the CCGT cycle, and steam and water used during gasification, and sometimes air, are also taken from it. Losses arising from coal gasification and generator gas cleaning reduce the efficiency of the CCGT unit. Yet, with rational design, it can be quite high.

The most developed and practically applied technologies of coal gasification in a bulk bed, in a fluidized bed and in a stream. Oxygen is used as an oxidizing agent, less often air. The use of industrially developed technologies for purifying synthesis gas from sulfur compounds requires gas cooling to 40 ° C, which is accompanied by additional pressure and performance losses. The cost of gas cooling and purification systems is 15-20% of the total cost of TPPs. Currently, high-temperature (up to 540-600 ° C) gas cleaning technologies are being actively developed, which will reduce the cost of systems and simplify their operation, as well as reduce the losses associated with cleaning. Regardless of the gasification technology, 98-99% of coal energy is transferred to combustible gas.

In 1987-91. In the USSR, under the state program "Environmentally friendly energy", VTI and CKTI, together with design institutes, worked out in detail several CCGT units with coal gasification.

The unit capacity of the units (net) was 250-650 MW. All three gasification technologies mentioned above were considered in relation to the most common coals: Berezovsky brown, Kuznetsk stone and ASh, which are very different in composition and properties. Efficiency from 39 to 45% and very good environmental performance were obtained. In general, these projects were in line with the then world level. Abroad, similar CCGT units have already been implemented on demonstration models with a unit capacity of 250-300 MW, and domestic projects were discontinued 10 years ago.

Despite this, gasification technologies are of interest to our country. In VTI, in particular, they continue

experimental work at the gasification plant using the “hearth” method (with a bulk bed and liquid slag removal) and optimization studies of CCGT schemes.

Taking into account the moderate sulfur content in the most promising domestic coals and the progress achieved in the economic and environmental indicators of traditional pulverized coal-fired power units, with which these CCGT units will have to compete, the main reasons for their development are the possibility of achieving higher thermal efficiency and less difficulties in removing CO2 from the cycle. in case it is needed (see below). Bearing in mind the complexity of the CCGT unit with gasification and the high cost of their development and development, it is advisable to take the CCGT unit efficiency at the level of 52-55%, the unit cost of 1-1.05 of the cost of the coal block, SO2 and NOX emissions.< 20 мг/м3 и частиц не более 10 мг/м3. Для достижения их необходимо дальнейшее развитие элементов и систем ПГУ.

Reducing the temperature of the combustible gas at the outlet of the gasifier to 900-1000 ° C, cleaning it from sulfur compounds and particles and directing it into the combustion chamber of the GTU at an elevated temperature (for example, 500-540 ° C at which pipelines and fittings can be made of inexpensive steels ), using air rather than oxygen blast, reducing pressure and heat losses in the gas-air duct of the gasification system and using heat exchange circuits closed inside it, it is possible to reduce the loss of performance associated with gasification from 16-20 to 10-12% and significantly reduce power consumption by own needs.

Projects carried out abroad also indicate a significant decrease in the unit cost of TPPs with CCGT with coal gasification with an increase in productivity and unit capacity of equipment, as well as with an increase in technology development.

Another possibility is a CCGT unit with coal combustion in a fluidized bed under pressure. The required air is supplied to the bed by a gas turbine compressor with a pressure of 1-1.5 MPa, the combustion products, after cleaning from ash and entrainment, expand in the gas turbine and perform useful work. The heat released in the bed and the heat of the exhaust gases in the turbine are used in the steam cycle.

Carrying out the process under pressure while maintaining all the advantages characteristic of coal combustion in a fluidized bed can significantly increase the unit capacity of steam generators and reduce their dimensions with a more complete combustion of coal and sulfur binding.

The advantages of a CCGT unit with KSD are complete (with an efficiency> 99%) combustion of various types of coal, high heat transfer coefficients and small heating surfaces, low (up to 850 ° C) combustion temperatures and, as a result, small (less than 200 mg / m3) NOX emissions, no slagging, the possibility of adding a sorbent (limestone, dolomite) to the layer and binding in it 90-95% of the sulfur contained in the coal.

High efficiency (40-42% in condensing mode) is achieved in a CCGT unit with KSD at moderate power (approx. 100 MW el.) And subcritical steam parameters.

Due to the small size of the boiler and the absence of desulfurization, the area occupied by the CCGT unit with KSD is small. Possible block-complete delivery of their equipment and modular construction with a reduction in its cost and terms.

For Russia, CCGTs with KSD are promising, first of all, for the technical re-equipment of coal-fired CHPPs in confined areas, where it is difficult to locate the necessary environmental protection equipment. Replacing old boilers with HSGs with GTUs will also significantly improve the efficiency of these CHPPs and increase their electrical capacity by 20%.

At VTI, on the basis of domestic equipment, several standard sizes of CCGT with KSD were worked out.

Under favorable economic conditions, such CCGT units could be implemented in our country in a short time.

CCGT technology with KSD is simpler and more familiar to power engineers than gasification plants, which are complex chemical production. Various combinations of both technologies are possible. Their purpose is to simplify gasification and gas purification systems and reduce their characteristic losses from one side, and increase the temperature of gases in front of the turbine and gas turbine power in schemes with KSD on the other side.

Some restraint of the public and reflecting its sentiments of experts and governments in assessing the prospects for a wide and long-term use of coal is associated with growing CO2 emissions into the atmosphere and fears that these emissions may cause global climate change, which will have catastrophic consequences.

Discussion of the solidity of these fears (they are not shared by many competent specialists) is not the subject of this article.

However, even if they turn out to be correct, in 40-60 years, when it is required, or even earlier, it is quite realistic to create competitive TPPs (or energy technology enterprises) operating on coal with negligible CO2 emissions into the atmosphere.

Already today, a significant reduction in CO2 emissions into the atmosphere from TPPs, in particular coal-fired ones, is possible with the combined generation of electricity and heat and increasing the efficiency of TPPs.

Using the already mastered processes and equipment, it is possible to design a CCGT unit with coal gasification, conversion of СО + Н2О into Н2О and СО2, and removal of СО2 from synthesis gas.

The project used a Siemens GTU U94.3A with an initial gas temperature according to the ISO standard 1190 ° C, a PRENFLO gasifier (in-line, on dry dust of Pittsburgh coal No. 8 and oxygen blast), a shift reactor and removal of acid gases: H2S, COS and CO2 in to the Rectisol system of the Lurgi company.

The advantages of the system are the small size of the equipment for carrying out CO2 removal processes at high (2 MPa) pressure, high partial pressure and CO2 concentration. Removal of about 90% of CO2 is taken for economic reasons.

A decrease in the efficiency of the initial CCGT unit when removing CO2 occurs due to the loss of exergy during the exothermic conversion of CO (by 2.5-5%), additional energy losses during the separation of CO2 (by 1%) and due to a decrease in the consumption of combustion products through the gas turbine and the boiler. utilizer after separation of СО2 (by 1%).

The inclusion of devices for the conversion of CO and the removal of CO2 from the cycle in the circuit increases the unit cost of a CCGT with GF by 20%. Liquefying CO2 will add another 20%. The cost of electricity will increase by 20 and 50%, respectively.

As mentioned above, domestic and foreign studies indicate the possibility of a further significant - up to 50-53% - increase in the efficiency of CCGT units with coal gasification, and, consequently, their modifications with removal of CO2.

EPRI in the USA promotes the creation of coal-fired power complexes that are competitive with thermal power plants using natural gas. It is advisable to construct them in stages in order to reduce the initial capital investments and recoup them faster, while at the same time meeting the current environmental requirements.

The first stage: a promising environmentally friendly CCGT unit with GF.

Second stage: introduction of a CO2 removal and transportation system.

The third stage: the organization of the production of hydrogen or clean transport fuel.

There are much more radical proposals. In examines, for example, a coal-fired power plant with "zero" emissions. Its technological cycle is as follows. The first step is gasification of a coal-water suspension with the addition of hydrogen and obtaining CH4 and H2O. Coal ash is removed from the gasifier, and the steam-gas mixture is purified.

In the second step, carbon, which has passed into a gaseous state, in the form of CO2 is bound by calcium oxide in a reformer, where purified water is also supplied. The hydrogen formed in it is used in the hydrogasification process and is supplied, after fine purification, to a solid oxide fuel cell to generate electricity.

In the third step, the CaCO3 formed in the reformer is calcined using the heat released in the fuel cell and the formation of CaO and concentrated CO2 suitable for further processing.

The fourth step is to convert the chemical energy of hydrogen into electricity and heat, which is returned to the cycle.

CO2 is removed from the cycle and mineralized in the process of carbonization of such minerals as, for example, magnesium silicate, which is ubiquitous in nature in quantities that are orders of magnitude higher than coal reserves. The end products of carbonation can be disposed of in depleted mines.

The efficiency of converting coal into electricity in such a system will be about 70%. At a total cost of CO2 removal of US $ 15-20 per tonne, it would increase the electricity cost by about US $ 0.01 / kWh.

The considered technologies are still a matter of the distant future.

Today, the most important measure to ensure sustainable development is economically viable energy conservation. In the field of production, it is associated with an increase in the efficiency of energy conversion (in our case, at thermal power plants) and the use of synergetic technologies, i.e. combined production of several types of products in one installation, something like energy technology, popular in our country 40-50 years ago. Of course, now it is being carried out on a different technical basis.

The first example of such installations was CCGT with gasification of oil residues, which are already being used on commercial terms. The fuel for them is the waste of oil refineries (for example, coke or asphalt), and the products are electricity, process steam and heat, commercial sulfur and hydrogen used at the refinery.

District heating with combined generation of electricity and heat, which is widespread in our country, is essentially an energy-saving synergetic technology and deserves much more attention in this capacity than is currently being given to it.

Under the current “market” conditions in the country, the costs of generating electricity and heat at steam turbine CHPPs equipped with outdated equipment and not optimally loaded are in many cases excessively high and do not ensure their competitiveness.

This provision should by no means be used to revise the fundamentally sound idea of ​​cogeneration of electricity and heat. Of course, the issue is not resolved by the redistribution of costs between electricity and heat, the principles of which have been fruitlessly discussed in our country for many years. But the economy of CHP plants and heat supply systems as a whole can be significantly improved by improving technologies (binary gas-fired CCGT units, coal-fired CCGT units, pre-insulated heat pipelines, automation, etc.), organizational and structural changes and government regulation measures. They are especially needed in a country as cold and with a long heating period as ours.

It is interesting to compare various heat and power technologies with each other. The Russian experience, both digital (pricing) and methodological, does not provide grounds for such comparisons, and the attempts made in this direction are not convincing enough. One way or another, you have to attract foreign sources.

The calculations of many organizations, carried out without coordinating the initial data, both in our country and abroad, show that without a radical change in the price ratio between natural gas and coal, which has now developed abroad (gas per unit of heat is about twice as expensive as coal), modern CCGT units remain competitive. advantages over coal-fired power units. For this to change, the ratio of these prices must increase to ~ 4.

An interesting forecast for the development of technology was made in. It shows, for example, that the use of fuel oil steam power units is forecasted until 2025, and gas power units - until 2035; the use of CCGT with coal gasification - from 2025, and gas-fired fuel cells - from 2035; CCGT units fueled by natural gas will be used after 2100, the release of CO2 will begin after 2025, and at CCGT units with coal gasification after 2055.

With all the uncertainties of such forecasts, they draw attention to the essence of long-term energy problems and possible ways to solve them.

With the development of science and technology, which is taking place in our time, the processes taking place in thermal power plants are increasingly intensified and complicated. The approach to their optimization is changing. It is carried out not according to technical, it was earlier, but according to economic criteria reflecting the requirements of the market, which are changing and require increased flexibility of heat and power facilities, their ability to adapt to changing conditions. Designing power plants over 30 years of almost unchanged operation is now impossible.

Liberalization and introduction of market relations in the electric power industry have caused serious changes in heat and power technologies, ownership structure and methods of financing energy construction in recent years. Commercial power plants have appeared, operating on a free electricity market. The approaches to the selection and design of such power plants are very different from traditional ones. Often, commercial TPPs equipped with powerful CCGT units are not provided with contracts that guarantee year-round uninterrupted supplies of gaseous fuel, and must enter into non-guaranteeing contracts with several gas suppliers or be backed up with more expensive liquid fuel with an increase in the unit cost of TPPs by 4-5%.

Since 65% of the life cycle costs of basic and semi-peak TPPs are related to the cost of fuel, increasing their efficiency is the most important task. Its relevance today has even increased, taking into account the need to reduce specific emissions into the atmosphere.

In market conditions, the requirements for the reliability and availability of TPPs have increased, which are now being evaluated from a commercial standpoint: readiness is necessary when the operation of TPPs is in demand, and the price of unavailability at different times is significantly different.

Compliance with environmental requirements and support from local authorities and the public is essential.

It is generally advisable to increase power during peak load periods, even if this is achieved at the cost of some degradation in efficiency.

Measures to ensure the reliability and readiness of TPPs are specially considered. To this end, MTBF and mean time to recovery are calculated at the design stage, and the commercial efficiency of possible ways to improve availability is assessed. Much attention is paid to

improvement and quality control of suppliers of equipment and components, and in the design and construction of TPPs, as well as technical and organizational aspects of maintenance and repairs.

In many cases, forced shutdowns of power units are the result of malfunctions with their plant auxiliary equipment. With this in mind, the concept of maintenance of the entire TPP is gaining popularity.

Another significant development was the proliferation of branded service. The contracts for it provide for the contractor's guarantees for the performance of current, medium and major repairs within a specified time; the work is performed and supervised by qualified personnel, if necessary in the factory; the problem of spare parts is mitigated, etc. All this significantly increases the availability of hydropower plants and reduces the risks of their owners.

Fifteen or twenty years ago, the power industry in our country was at the most modern level, perhaps, except for gas turbines and automation systems. New technologies and equipment were actively developed, which were not inferior in technical level to foreign ones. Industrial projects were based on research from powerful industry and academic institutions and universities.

Over the past 10-12 years, the potential in the electric power industry and power machine building has been largely lost. The development and construction of new power plants and advanced equipment have practically ceased. Rare exceptions are the development of gas turbines GTE-110 and GTE-180 and the automated process control system KVINT and Kosmotronic, which have become a significant step forward, but have not eliminated the existing gap.

Today, given the physical deterioration and obsolescence of equipment, the Russian power industry is in dire need of renewal. Unfortunately, there are currently no economic conditions for active investment in energy. If such conditions arise in the coming years, domestic scientific and technical organizations will be able - with rare exceptions - to develop and manufacture the advanced equipment necessary for the power industry.

Of course, the development of its production will be associated with large costs for manufacturers, and the use - before the accumulation of experience - with a known risk for the owners of power plants.

It is necessary to look for a source to compensate for these costs and risks, since it is clear that own production of unique energy equipment meets the national interests of the country.

The power engineering industry itself can do a lot for itself, developing the export of its products, thereby creating accumulations for its technical improvement and quality improvement. The latter is essential for long-term stability and prosperity.

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