Presentation on the topic of turbines in physics. Steam turbine

The first predecessor of modern steam turbines can be considered a toy engine, which was invented back in the 2nd century. before. AD Alexandrian scientist Heron. The first predecessor of modern steam turbines can be considered a toy engine, which was invented back in the 2nd century. before. AD Alexandrian scientist Heron.

In 1629, the Italian Branca created a design for a wheel with blades. It was supposed to rotate if a stream of steam hit the wheel blades with force. This was the first design of a steam turbine, which later became known as an active turbine. In 1629, the Italian Branca created a design for a wheel with blades. It was supposed to rotate if a stream of steam hit the wheel blades with force. This was the first design of a steam turbine, which later became known as an active turbine. The steam flow in these early steam turbines was not concentrated, and most of its energy was dissipated in all directions, resulting in significant energy losses. The steam flow in these early steam turbines was not concentrated and much of its energy was dissipated in all directions, resulting in significant energy losses.

A steam turbine consists of a series of rotating disks mounted on a single axis, called a turbine rotor, and a series of alternating stationary disks mounted on a base, called a stator. The rotor disks have blades on the outside; steam is supplied to these blades and spins the disks. The stator disks have similar blades mounted at opposite angles, which serve to redirect the flow of steam to the following rotor disks. A steam turbine consists of a series of rotating disks mounted on a single axis, called a turbine rotor, and a series of alternating stationary disks mounted on a base, called a stator. The rotor disks have blades on the outside; steam is supplied to these blades and spins the disks. The stator disks have similar blades mounted at opposite angles, which serve to redirect the flow of steam to the following rotor disks.

Types of steam engines. Steam turbines, formally a type of steam engine, are still widely used to drive electricity generators. Approximately 86% of the world's electricity is generated using steam turbines. Steam turbines, formally a type of steam engine, are still widely used to drive electricity generators. Approximately 86% of the world's electricity is generated using steam turbines.

Energy hidden in fossil fuels such as coal, oil or natural gas, cannot be immediately obtained in the form of electricity. The fuel is first burned. The released energy first heats the water and turns it into steam. The steam rotates the turbine, which in turn rotates an electric generator that produces current. The energy hidden in fossil fuels such as coal, oil or natural gas cannot be immediately obtained in the form of electricity. The fuel is first burned. The released energy first heats the water and turns it into steam. The steam rotates the turbine, which in turn rotates an electric generator that produces current.

Ship steam turbines In our country, steam turbines are built with a power ranging from several kilowatts to a kilowatt. Turbines are used in thermal power plants and on ships. Gas turbines, in which gas combustion products are used instead of steam, are gradually becoming more widely used. In our country, steam turbines with power ranging from several kilowatts to kW are built. Turbines are used in thermal power plants and on ships. Gas turbines, in which gas combustion products are used instead of steam, are gradually becoming more widely used.

• Prepared by Andreev Dmitry,
• student of 190 TM group.
• Head L.A. Pleshcheva,
• teacher

• Shadrinsk 2015

an external combustion heat engine that converts the energy of heated steam into mechanical work of the reciprocating movement of the piston, and then into the rotational movement of the shaft. In more in a broad sense steam engine - any external combustion engine that converts steam energy into mechanical work.

• an external combustion heat engine that converts the energy of heated steam into mechanical work of the reciprocating movement of the piston, and then into the rotational movement of the shaft. In a broader sense, a steam engine is any external combustion engine that converts steam energy into mechanical work.

It was not for nothing that the nineteenth century was called the century of steam. With the invention of the steam engine, a real revolution took place in industry, energy, and transport. It became possible to mechanize work that previously required too many human hands. Expansion of volumes industrial production set the energy industry the task of increasing engine power in every possible way. However, initially it was not high power that brought the steam turbine to life... The hydraulic turbine as a device for converting the potential energy of water into the kinetic energy of a rotating shaft has been known since ancient times. The steam turbine has an equally long history, with one of the first designs known as Heron's turbine and dating back to the first century BC. However, let us immediately note that until the 19th century, turbines driven by steam were more likely technical curiosities, toys, than real industrially applicable devices.

• The hydraulic turbine as a device for converting the potential energy of water into the kinetic energy of a rotating shaft has been known since ancient times. The steam turbine has an equally long history, with one of the first designs known as Heron's turbine and dating back to the first century BC. However, let us immediately note that until the 19th century, turbines driven by steam were more likely technical curiosities, toys, than real industrially applicable devices.

And only with the beginning of the industrial revolution in Europe, after the widespread practical introduction of D. Watt’s steam engine, inventors began to take a closer look at the steam turbine, so to speak, “closely.” The creation of a steam turbine required in-depth knowledge physical properties steam and the laws of its expiration. Its production became possible only with sufficient high level technology for working with metals, since the required manufacturing accuracy of individual parts and the strength of the elements were significantly higher than in the case of a steam engine. However, time passed, technology improved, and the hour practical application steam turbine broke. Primitive steam turbines were first used in sawmills in the eastern United States in 1883-1885. for driving circular saws.

• The Laval steam turbine is a wheel with blades. A jet of steam generated in the boiler escapes from the pipe (nozzle), presses on the blades and spins the wheel. Experimenting with different tubes for supplying steam, the designer came to the conclusion that they should have a cone shape. This is how the Laval nozzle, which is still used today, appeared (patent 1889). This important discovery the inventor did it rather intuitively; it took several more decades for theorists to prove that a nozzle of this particular shape gives the best effect.

• He began working on turbines in 1881, and three years later he was given a patent for his own design: Parsons connected a steam turbine to a generator electrical energy. With the help of a turbine it became possible to generate electricity, and this immediately increased public interest in steam turbines. As a result of 15 years of research, Parsons created the most advanced multi-stage jet turbine at that time. He made several inventions that increased the efficiency of this device (he improved the design of the seals, methods for attaching the blades to the wheel, and the speed control system).

• Created a comprehensive theory of turbomachines. He developed an original multi-stage turbine, which was successfully demonstrated at the World Exhibition held in the capital of France in 1900. For each stage of the turbine, Rato calculated the optimal pressure drop, which ensured high overall coefficient useful action cars.

In his machine, the rotation speed of the turbine was lower, and the steam energy was used more fully. Therefore, Curtis turbines were smaller and more reliable in design. One of the main areas of application of steam turbines is ship propulsion systems. The first ship with a steam turbine engine, the Turbinia, built by Parsons in 1894, reached speeds of up to 32 knots (about 59 km/h).

• In his machine, the rotation speed of the turbine was lower, and the steam energy was used more fully. Therefore, Curtis turbines were smaller and more reliable in design. One of the main areas of application of steam turbines is ship propulsion systems. The first ship with a steam turbine engine, the Turbinia, built by Parsons in 1894, reached speeds of up to 32 knots (about 59 km/h).

The American Doble steam engine was produced in extremely limited quantities: from 1923 to 1932, only 42 copies were made. The example in the illustration is dated 1929. Brooks steam cars leaving the assembly line at a factory in Stratford, Ontario, 1926. STEAM TURBINE Steam turbine– water steam into mechanical work.

• Steam turbine– primary steam engine with rotational movement of the working body - the rotor and a continuous working process; serves to convert thermal energy water steam into mechanical work.

• Schematic longitudinal section of an active turbine with three pressure stages: 1 - annular fresh steam chamber; 2 - first stage nozzles; 3 - first stage working blades; 4 - second stage nozzles; 5 - working blades of the second stage; 6 - third stage nozzles; 7 - third stage working blades.

• Schematic section of a small jet turbine: 1 - annular fresh steam chamber; 2 - unloading piston; 3 - connecting steam line; 4 - rotor drum; 5, 8 - working blades; 6, 9 - guide vanes; 7 - body

• Double-casing steam turbine (with covers removed): 1 - high-pressure housing; 2 - labyrinth seal; 3 - Curtis wheel; 4 - high pressure rotor; 5 - coupling; 6 - low pressure rotor; 7 - low pressure housing.

Sources:

• Steam engines [ Electronic resource] - https://ru.wikipedia.org/wiki/%D0%9F%D0%B0%D1%80%D0%BE%D0%B2%D0%B0%D1%8F_%D0%BC%D0%B0 %D1%88%D0%B8%D0%BD%D0%B0 (access time 09/02/2015)

Subject Physics

Class 8 a class

Lesson on the topic “Steam turbine. Gas turbine. Heat engine efficiency. Ecological problems use of heat engines.

Basic textbook by A.V. Peryshkin Physics 8; M.: Bustard

The purpose of the lesson:

Educational

ensure during the lesson the study of the structure and operating principle of a steam and jet turbine;

formulate in students the concept of heat engine efficiency and consider ways to increase it;

reveal the role and significance of TD in modern civilization

promote the ability to compare the efficiency of a real and ideal heat engine;

show the positive and negative role of heat engines in human life.

Developmental

continue to develop the ability to analyze, highlight the main thing in the material being studied, compare, systematize and draw conclusions;

development of students’ horizons and their acquisition of new natural science knowledge

Educational

continue formation scientific worldview and show that knowledge is based on facts obtained from experience, show the infinity of the process of knowledge;

Lesson type: Combined

Forms of student work: individual and collective, observations.

Necessary Technical equipment: computer, projector

Lesson structure and flow

1. Organizational stage.

* checking the presence of students in the class;

* reminder of TB work in the office;

* friendly attitude of the teacher and students;

* organizing the attention of all students;

* message of the topic and objectives of the lesson.

2. Stage of updating basic knowledge:

Frontal conversation on the following issues:

1) Which engine is called an internal combustion engine?

2) What are the main parts of the simplest internal combustion engine?

3) What physical phenomena occur during the combustion of a combustible mixture in an internal combustion engine?

3. Stage of learning new material.

1. Setting the goal of the lesson.

2. Study of the concepts of “steam turbine” gas turbine", "Heat engine efficiency", the impact of heat engines on the environment

STEAM TURBINE

“In previous lessons we learned about the internal combustion engine. Today we will get acquainted with another type of engine in which steam or gas heated to high temperature rotates the engine shaft without the help of a piston, connecting rod and crankshaft"
(see slide 4 “Steam turbine model”)

Comments on the demo:

steam creating pressure on the turbine blades causes it to rotate along with the shaft on which it is located and lift a weight attached to the thread

(see slide 5 “Steam turbine”)

Practical Use This process is widely used in the energy industry

(see slide 6 "Operation of a thermal power plant") .

Comments on the slide.

Operating principle of the thermal power plant:

Turbine - generator - electric current

Other applications of steam turbines:

GAS TURBINE

An example of an engine in which gas heated to a high temperature rotates the engine shaft(see slide 7 “Jet engine”) :

Comments:

When the turbine is operating, the rotor compressor rotates and sucks air through inlet nozzle . The air, passing through a series of compressor blades, is compressed, its pressure and temperature increase. Compressed air enters combustion chambers . At the same time, liquid fuel (kerosene, fuel oil) is injected into it under high pressure through a nozzle. When fuel burns, the air heats up to 1500-2200 0 C. The air expands and its speed increases. Air and combustion products moving at high speed are directed into gas turbine . Moving from stage to stage, they give up their kinetic energy to the turbine rotor blades, while their temperature decreases to 550 0 C. Part of the energy received by the turbine is spent on rotating the compressor, and the rest is used, for example, to rotate an airplane propeller or the rotor of an electric generator. Exhaust air together with combustion products at a pressure close to atmospheric and at a speed of more than 500 m/s is ejected through outlet nozzle into the atmosphere.

Application in aviation, energy, etc.

HEAT ENGINE EFFICIENCY:

Look at slide 8 “Efficiency of heat engines”

determination of efficiency Look at slide 9 “Efficiency values ​​of various heat engines”-

we talk about engine types and engine efficiency

ECOLOGICAL PROBLEMS OF USING HEAT MACHINES

ways to reduce harmful effects on the environment:

watch the interactive lecture “Ecological problems of using heat engines”

Look at slide 10 “This is interesting...”

Interesting fact!

The combustion of fuel is accompanied by the release into the atmosphere carbon dioxide. The Earth's atmosphere currently contains about 2600 billion tons of carbon dioxide (about 0.0033%). Before the period of rapid development of energy and transport, the amount of carbon dioxide absorbed during photosynthesis by plants and dissolved in the ocean was equal to the amount of gas released during respiration and decay. In recent decades, this balance has become increasingly disrupted. Currently, due to the combustion of coal, oil and gas, an additional 20 billion tons of carbon dioxide enter the Earth's atmosphere annually.

Look at slide 11 “Environmental problems”

"MOU Average comprehensive school No. 1 with in-depth study of the English language"

"MOU Secondary School No...."

Abstract on the topic:

"Steam turbine"

Completed by: student... class...

Checked by: physics teacher...

3-Steam turbine

3-Classification

4-Pros and cons

5-From the history of the steam turbine

6-Carl-Gustav-Patrick de Laval

8- Charles Algernon Parsons

10- Marine boiler and turbine installations

12-Triumph of steam turbine energy

13-Appendix

15-Literature

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Steam turbine - a type of steam engine in which a jet of steam acting on the rotor blades causes it to rotate. Currently, steam turbines are used in conjunction with fossil fuel boilers or nuclear reactors in power plants and large vessels and ships. Steam turbines have been used as prime movers in industrial cogeneration plants for many years. The steam generated in the steam boiler expands and passes through the turbine blades under high pressure. The turbine rotates and produces mechanical energy, which is used by a generator to produce electricity.>

The electrical power of the system depends on how large the steam pressure difference is at the turbine inlet and outlet.

For efficient work steam must be supplied to the turbine with high pressure and temperature (42 bar/400°C or 63 bar/480°C), (Soviet condensing turbines K-800-240 rated power 800 MW, initial pressure 240 bar, 540°C). Such conditions place increased demands on boiler equipment, which leads to a progressive increase in capital expenditures and maintenance costs.

The advantage of the technology is the ability to use a wide range of fuels in the boiler, including solid ones. However, the use of heavy oil fractions and solid fuel reduces the environmental performance of the system, which is determined by the composition of combustion products leaving the boiler. By default, steam turbines produce much more heat than electricity, resulting in high installed capacity costs.

Classification

Condensing systems are actually for the production of electricity, all energy is spent on the production of electricity, the steam output from the turbine to the condenser is produced at the lowest possible pressure and temperature (about 0.03 bar, 30 ° C) to increase thermal efficiency. as a rule, they have high power (in thermal power plants up to 1200 MW, in nuclear power plants up to 1500 MW), used only in power plants. Marked K-800-240, where

K - turbine type (condensing)

800 - rated power, MW

240 - fresh steam pressure, kgf/cm2

With back pressure, the entire steam output is produced with high pressure and temperature determined by necessity, used for heat supply and production, the electrical power is limited by the thermal power of the heat consumer. Marked P-100-130/15, where

P - turbine type (with back pressure)

15 - back pressure, kgf/cm2

District heating and industrial combine the two previous types: part of the steam is taken for production or heating, and part reaches the condenser going through a full cycle; they are used in combined heat and power plants. Turbines with heating extraction are marked T-100/120-130, where

T - turbine type (with heating extraction)

100 - rated power, MW

120 - maximum power, MW

130 - fresh steam pressure, kgf/cm2

Turbines with production selection are marked P-25/30-90/13, where

P - turbine type (with production selection)

25 - rated power, MW

30 - maximum power, MW

90 - fresh steam pressure, kgf/cm2

13 - nominal steam pressure in production extraction, kgf/cm2

pros

operation of steam turbines is possible on various types fuels: gaseous, liquid, solid

high unit power

free choice of coolant

wide power range

impressive resource of steam turbines

Minuses

high inertia of steam installations (long start-up and stop times)

high cost of steam turbines

low volume of electricity produced in relation to the volume of thermal energy

expensive repairs of steam turbines

reduction in environmental performance in the case of using heavy fuel oils and solid fuels

From the history of the steam turbine

It was not for nothing that the nineteenth century was called the age of steam. With the invention of the steam engine, a real revolution took place in industry, energy, and transport. It became possible to mechanize work that previously required too many human hands. Railways dramatically expanded the possibilities of transporting goods by land. Huge ships took to the sea, capable of moving against the wind and guaranteeing the timely delivery of goods. The expansion of industrial production volumes has confronted the energy sector with the task of increasing engine power in every possible way. However, initially it was not high power that brought the steam turbine to life...

The hydraulic turbine as a device for converting the potential energy of water into the kinetic energy of a rotating shaft has been known since ancient times. The steam turbine has an equally long history, as one of the first designs is known as the “Heronian turbine” and dates back to the first century BC. However, let us immediately note that until the 19th century, turbines driven by steam were more likely technical curiosities, toys, than real industrially applicable devices.

And only with the beginning of the industrial revolution in Europe, after the widespread practical introduction of D. Watt’s steam engine, inventors began to take a closer look at the steam turbine, so to speak, “closely.” The creation of a steam turbine required a deep knowledge of the physical properties of steam and the laws of its flow. Its manufacture became possible only with a sufficiently high level of technology for working with metals, since the required precision in the manufacture of individual parts and the strength of the elements were significantly higher than in the case of a steam engine.

Unlike a steam engine, which performs work by using the potential energy of steam and, in particular, its elasticity, a steam turbine uses the kinetic energy of a steam jet, converting it into rotational energy of the shaft. The most important feature of water vapor is its high rate of flow from one medium to another, even with a relatively small pressure drop. Thus, at a pressure of 5 kgf/m2, the steam jet flowing from the vessel into the atmosphere has a speed of about 450 m/s. In the 50s of the last century it was established that for effective use kinetic energy of steam, the peripheral speed of the turbine blades at the periphery must be at least half the speed of the blowing jet, therefore, with a turbine blade radius of 1 m, it is necessary to maintain a rotation speed of about 4300 rpm. The technology of the first half of the 19th century did not know bearings capable of withstanding such speeds for a long time. Based on his own practical experience, D. Watt believed that high speeds movements of machine elements unattainable in principle, and in response to a warning about the threat that a turbine could pose to the steam engine he invented, he answered: “What kind of competition can we talk about if, without the help of God, it is impossible to make the working parts move at a speed of 1000 feet per second ?

However, time passed, technology improved, and the hour for the practical use of the steam turbine struck. Primitive steam turbines were first used in sawmills in the eastern United States in 1883-1885. for driving circular saws. Steam was supplied through the axis and then, expanding, was directed through pipes in the radial direction. Each of the pipes ended with a curved tip. Thus, in design, the described device was very close to the Heron turbine, had extremely low efficiency, but was more suitable for driving high-speed saws than a steam engine with its reciprocating piston movement. In addition, to heat the steam, according to the concepts of that time, waste fuel was used - sawmill waste.

However, these first American steam turbines were not widely used. Their influence on further history There is practically no technology. The same cannot be said about the inventions of the Swede of French origin, de Laval, whose name is known to any engine specialist today.

Carl Gustav Patrick de Laval

De Laval's ancestors were Huguenots who were forced to emigrate to Sweden at the end of the 16th century due to persecution in their homeland. Carl Gustav Patrick (“the main name” was still considered Gustav) was born in 1845 and received an excellent education, graduating from the Institute of Technology and University in Uppsala. In 1872, de Laval began working as a chemical and metallurgical engineer, but soon became interested in the problem of creating an effective milk separator. In 1878, he managed to develop a successful version of the separator design, which became widespread; Gustav used the proceeds to expand work on a steam turbine. It was the separator that gave the impetus to start working on the new device, since it needed a mechanical drive capable of providing a rotation speed of at least 6000 rpm.

In order to avoid the use of any kind of multipliers, de Laval proposed placing the separator drum on the same shaft with a simple jet-type turbine. In 1883, an English patent was taken out for this design. De Laval then moved on to develop a single-stage active-type turbine, and already in 1889 he received a patent for an expanding nozzle (and today the term “Laval nozzle” is in common use), which makes it possible to reduce the steam pressure and increase its speed to supersonic. Soon after this, Gustav was able to overcome other problems that arose in the production of a functional active turbine. So, he proposed using a flexible shaft and a disk of equal resistance and developed a method for securing the blades in the disk.

On international exhibition in Chicago, held in 1893, a small de Laval turbine with a power of 5 hp was introduced. with a rotation speed of 30,000 rpm! The enormous rotation speed was an important technical achievement, but at the same time it became the Achilles heel of such a turbine, since for practical use it required the inclusion of a reduction gear in the power plant. At that time, gearboxes were manufactured mainly as single-stage gearboxes, so the diameter of a large gear was often several times greater than the size of the turbine itself. The need to use bulky gear reduction gears prevented the widespread adoption of de Laval turbines. The largest single-stage turbine with a power of 500 hp. had a steam consumption of 6...7 kg/hp h.

An interesting feature of Laval’s work can be considered his “bare empiricism”: he created completely workable designs, the theory of which was later developed by others. Thus, the theory of a flexible shaft was subsequently deeply studied by the Czech scientist A. Stodola, who also systematized the main issues of calculating the strength of turbine disks of equal resistance. It was the lack of a good theory that did not allow de Laval to achieve great success; moreover, he was an enthusiastic person and easily switched from one topic to another. Neglecting the financial side of the matter, this talented experimenter, not having time to implement his next invention, quickly lost interest in it, being carried away by the new idea. A different kind of person was the Englishman Charles Parsons, son of Lord Ross.