Interest in water vapor as an accessible source of energy appeared along with the first scientific knowledge of the ancients. People have been trying to tame this energy for three millennia. What are the main stages of this path? Whose reflections and projects have taught humanity to derive the maximum benefit from it?
Prerequisites for the appearance of steam engines
The need for mechanisms that can facilitate labor-intensive processes has always existed. Until about the middle of the 18th century, windmills and water wheels were used for this purpose. The possibility of using wind energy directly depends on the vagaries of the weather. And to use water wheels, factories had to be built along river banks, which is not always convenient and expedient. And the effectiveness of both was extremely low. Essentially needed new engine, easily manageable and devoid of these disadvantages.
The history of the invention and improvement of steam engines
The creation of a steam engine is the result of long deliberation, success and failure of the hopes of many scientists.
The beginning of the way
The first, one-off projects were just interesting curiosities. For example, Archimedes designed a steam cannon, Heron of Alexandria used the energy of steam to open the doors of ancient temples. And the researchers find notes on the practical use of steam energy for activating other mechanisms in the works Leonardo da Vinci.
Let's consider the most significant projects on this topic.
In the 16th century, the Arab engineer Tagi al-Din developed a project for a primitive steam turbine. However, it did not receive practical application due to the strong scattering of the steam jet supplied to the turbine wheel blades.
Fast forward to medieval France. Physicist and talented inventor Denis Papin, after many unsuccessful projects, stopped at the following design: a vertical cylinder was filled with water, over which a piston was installed.
The cylinder was heated, the water boiled and evaporated. The expanding steam lifted the piston. It was fixed at the upper lifting point and the cylinder was expected to cool down and steam condensed. After condensation of steam in the cylinder, a vacuum was formed. The piston, released from the fastening, was rushed into vacuum under the influence of atmospheric pressure. It was this piston fall that was supposed to be used as a working stroke.
So, the useful stroke of the piston was caused by the formation of a vacuum due to condensation of steam and external (atmospheric) pressure.
Because the Papen steam engine like most subsequent projects were named steam-atmospheric machines.
This design had a very significant drawback - the repeatability of the cycle was not provided. Denis comes up with the idea of getting steam not in a cylinder, but separately in a steam boiler.
Denis Papin went down in the history of the creation of steam engines as the inventor of a very important detail - the steam boiler.
And since they began to receive steam outside the cylinder, the engine itself passed into the category of external combustion engines. But due to the lack of a distribution mechanism that provides smooth operation, these projects have found almost no practical application.
A new milestone in the development of steam engines
For about 50 years, it has been used for pumping water in coal mines Thomas Newcomen's steam pump. It largely repeated the previous designs, but contained very important innovations - a pipe for removing condensed steam and a safety valve for releasing excess steam.
Its significant disadvantage was that the cylinder had to be heated before steam injection, then cooled before condensation. But the demand for such engines was so high that, despite their obvious inefficiency, the last copies of these machines served until 1930.
In 1765 English mechanic James Watt, taking up the improvement of the Newcomen machine, separated the condenser from the steam cylinder.
Now it is possible to keep the cylinder constantly heated. The efficiency of the machine immediately increased. In subsequent years, Watt significantly improved his model, equipping it with a device for supplying steam from one side or the other.
It became possible to use this machine not only as a pump, but also for driving various machine tools. Watt received a patent for his invention - a continuous steam engine. Mass production of these machines begins.
By the early 19th century, more than 320 Watt steam engines were in operation in England. Other European countries began to buy them as well. This contributed to a significant increase in industrial production in many sectors of both England itself and neighboring countries.
Twenty years earlier, Watt, in Russia, an Altai mechanic Ivan Ivanovich Polzunov worked on a steam engine project.
The factory bosses asked him to build a unit that would drive the blower of the smelting furnace.
The machine he built was two-cylinder and provided continuous operation of the device connected to it.
Having worked successfully for more than one and a half months, the boiler started to leak. By this time, Polzunov himself was no longer alive. They did not repair the car. And the wonderful creation of a lone Russian inventor was forgotten.
Due to the backwardness of Russia at that time the world learned about II Polzunov's invention with a great delay….
So, in order to drive a steam engine, it is necessary that the steam generated by the steam boiler, expanding, press on the piston or on the turbine blades. And then their movement was transmitted to other mechanical parts.
The use of steam engines in transport
Despite the fact that the efficiency of steam engines of that time did not exceed 5%, by the end of the 18th century they began to be actively used in agriculture and transport:
- a car with a steam engine appears in France;
- in the United States, a steamboat begins to run between the cities of Philadelphia and Burlington;
- a steam-powered railway locomotive was demonstrated in England;
- a Russian peasant from the Saratov province patented the crawler with a capacity of 20 liters. with.;
- Attempts were made repeatedly to build an aircraft with a steam engine, but, unfortunately, the low power of these units with the large weight of the aircraft made these attempts unsuccessful.
By the end of the 19th century, steam engines, having played their role in the technological progress of society, are giving way to electric motors.
Steam devices in the 21st century
With the advent of new energy sources in the 20th and 21st centuries, the need for the use of steam energy appears again. Steam turbines are becoming an integral part of nuclear power plants. The steam that powers them is obtained from nuclear fuel.
These turbines are also widely used in condensing thermal power plants.
In a number of countries, experiments are being carried out to obtain steam from solar energy.
Reciprocating steam engines have not been forgotten either. In the highlands as a locomotive steam locomotives are still used.
These reliable workers are both safer and cheaper. They do not need power lines, and fuel - wood and cheap coal are always at hand.
Modern technologies make it possible to capture up to 95% of atmospheric emissions and increase the efficiency to 21%, so people decided not to part with them for now and are working on a new generation of steam locomotives.
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Steam engines have been used as a driving engine in pumping stations, locomotives, steam ships, tractors, steam cars and others. Vehicle Oh. Steam engines contributed to the widespread commercial use of machines in factories and provided the energy basis for the industrial revolution in the 18th century. Later, steam engines were supplanted by internal combustion engines, steam turbines, electric motors and nuclear reactors, the efficiency of which is higher.
Steam engine in action
Invention and development
The first known device, powered by a steam, was described by Heron of Alexandria in the first century - the so-called "Heron's bath", or "eolipil". Steam escaping tangentially from the nozzles attached to the ball caused the latter to rotate. It is assumed that the transformation of steam into mechanical movement was known in Egypt during the Roman period and was used in simple devices.
First industrial engines
None of the devices described have actually been used as a means of solving useful problems. The first steam engine used in production was a "fire engine" designed by the English military engineer Thomas Severy in 1698. Severy received a patent for his device in 1698. It was a piston steam pump, and obviously not very efficient, since the heat of the steam was lost every time during the cooling of the container, and quite dangerous in operation, since due to high pressure steam containers and engine lines sometimes exploded. Since this device could be used both to rotate the wheels of a water mill, and to pump water out of mines, the inventor called him “the miner's friend”.
Then the English blacksmith Thomas Newcomen in 1712 demonstrated his “ naturally aspirated engine”Which was the first steam engine for which there could be commercial demand. It was an improved Severy steam engine in which Newcomen significantly reduced the operating pressure pair. Newcomen may have been based on a description of Papen's experiments in the Royal Society of London, to which he may have had access through fellow member Robert Hooke who worked with Papen.
Scheme of the Newcomen steam engine.
- Steam is shown in purple, water is shown in blue.
- Open valves are shown in green, closed valves in red
The first application of the Newcomen engine was to pump water out of a deep shaft. In the mine pump, the rocker arm was connected to a thrust that went down into the mine to the pump chamber. Reciprocating thrust movements were transmitted to the pump piston, which supplied water to the top. The valves of early Newcomen engines were opened and closed manually. The first improvement was the automation of the valves, which were driven by the machine itself. Legend has it that this improvement was made in 1713 by the boy Humphrey Potter, who had to open and close the valves; when he got tired of it, he tied the valve handles with ropes and went to play with the children. By 1715, a lever control system was already created, driven by the mechanism of the engine itself.
The first in Russia two-cylinder vacuum steam engine was designed by mechanic I.I.Polzunov in 1763 and built in 1764 to power the blower bellows at the Barnaul Kolyvano-Voskresensk factories.
Humphrey Gainsborough built a model of a steam engine with a condenser in the 1760s. In 1769, Scottish mechanic James Watt (possibly using Gainsborough's ideas) patented the first significant improvements to Newcomen's vacuum engine that made it significantly more fuel efficient. Watt's contribution was to separate the condensation phase of the vacuum engine in a separate chamber, while the piston and cylinder were at a steam temperature. Watt added several other important details to Newcomen's engine: he placed a piston inside the cylinder to expel the steam and converted the reciprocating motion of the piston into the rotational motion of the drive wheel.
Based on these patents, Watt built a steam engine in Birmingham. By 1782, Watt's steam engine was more than 3 times the capacity of Newcomen's machine. Improving the efficiency of the Watt engine led to the use of steam energy in industry. In addition, unlike the Newcomen engine, the Watt engine made it possible to transmit rotational motion, while in early models of steam engines the piston was connected to the rocker arm rather than directly to the connecting rod. This engine already had the basic features of modern steam engines.
A further increase in efficiency was the use of high pressure steam (American Oliver Evans and Englishman Richard Trevithick). R. Trevithick has successfully built high pressure industrial single-stroke engines known as "Cornish engines". They operated at 50 psi, or 345 kPa (3.405 atmospheres). However, as the pressure increased, there was also a great danger of explosions in machines and boilers, which initially led to numerous accidents. From this point of view, the most important element the high pressure machine had a safety valve that released excess pressure. Reliable and safe operation began only with the accumulation of experience and the standardization of procedures for the construction, operation and maintenance of equipment.
French inventor Nicholas-Joseph Cugno demonstrated in 1769 the first operational self-propelled steam vehicle: the "fardier à vapeur" (steam cart). Perhaps his invention can be considered the first automobile. The self-propelled steam tractor turned out to be very useful as a mobile source of mechanical energy that set in motion other agricultural machines: threshers, presses, etc. In 1788, a steamboat built by John Fitch already carried out a regular service on the Delaware River between Philadelphia (Pennsylvania) and Burlington (New York State). He lifted 30 passengers on board and walked at a speed of 7-8 miles per hour. J. Fitch's steamer was not commercially successful as a good overland route competed with it. In 1802, Scottish engineer William Symington built a competitive steamboat, and in 1807, American engineer Robert Fulton used Watt's steam engine to power the first commercially successful steamboat. On February 21, 1804, the first self-propelled railway steam locomotive, built by Richard Trevithick, was on display at the Penidarren Steel Works in Merthyr Tydville, South Wales.
Reciprocating steam engines
Reciprocating engines use steam energy to move a piston in a sealed chamber or cylinder. The reciprocating action of the piston can be mechanically converted into linear motion of piston pumps or into rotary motion to drive rotating parts of machine tools or vehicle wheels.
Vacuum machines
The early steam engines were initially called "fire engines" and Watt's "atmospheric" or "condensing" engines. They operated on a vacuum principle and are therefore also known as "vacuum motors". Such machines worked to drive reciprocating pumps, in any case, there is no evidence that they were used for other purposes. When operating a vacuum-type steam engine at the beginning of the cycle, steam low pressure admitted to the working chamber or cylinder. The inlet valve is then closed and the steam is cooled and condensed. In a Newcomen engine, cooling water is sprayed directly into the cylinder and condensate drains into a condensate collector. This creates a vacuum in the cylinder. Atmospheric pressure in the upper part of the cylinder presses on the piston and causes it to move downward, that is, the working stroke.
The constant cooling and reheating of the machine's slave cylinder was very wasteful and inefficient, however, these steam engines allowed water to be pumped from deeper depths than was possible before their appearance. In the year, a version of the steam engine appeared, created by Watt in collaboration with Matthew Boulton, the main innovation of which was the removal of the condensation process in a special separate chamber (condenser). This chamber was placed in a cold water bath and connected to the cylinder by a tube overlapped by a valve. A special small vacuum pump (a prototype of a condensate pump) was connected to the condensation chamber, driven by a rocker and used to remove condensate from the condenser. The resulting hot water was supplied by a special pump (a prototype of a feed pump) back to the boiler. Another radical innovation was the closure of the upper end of the working cylinder, in the upper part of which there was now low pressure steam. The same steam was present in the double jacket of the cylinder, maintaining its constant temperature. During the upward movement of the piston, this vapor was transmitted through special pipes to the lower part of the cylinder, in order to undergo condensation during the next stroke. The machine, in fact, ceased to be "atmospheric", and its power now depended on the pressure difference between the low-pressure steam and the vacuum that it could get. In the Newcomen steam engine, the piston was lubricated with a small amount of water poured onto it from above, in Watt's car this became impossible, since there was now steam in the upper part of the cylinder, it was necessary to switch to lubrication with a mixture of grease and oil. The same grease was used in the cylinder rod oil seal.
Vacuum steam engines, despite the obvious limitations of their efficiency, were relatively safe, they used low pressure steam, which was quite consistent with the general low level of boiler technology in the 18th century. Machine power was limited by low steam pressure, cylinder size, rate of fuel combustion and evaporation of water in the boiler, as well as the size of the condenser. The maximum theoretical efficiency was limited by the relatively small temperature difference on both sides of the piston; this made vacuum machines intended for industrial use too large and expensive.
Compression
The outlet window of the cylinder of the steam engine closes a little earlier than the piston reaches its extreme position, which leaves a certain amount of exhaust steam in the cylinder. This means that there is a compression phase in the cycle of operation, which forms the so-called "steam cushion", which slows down the movement of the piston in its extreme positions. It also eliminates the sudden pressure drop at the very beginning of the intake phase when fresh steam enters the cylinder.
Advance
The described effect of the "steam cushion" is also enhanced by the fact that the admission of fresh steam into the cylinder begins somewhat earlier than the piston reaches its end position, that is, there is some advance of the admission. This advance is necessary so that before the piston starts its working stroke under the action of fresh steam, the steam would have time to fill the dead space that arose as a result of the previous phase, that is, the intake-exhaust channels and the volume of the cylinder that is not used for the movement of the piston.
Simple extension
Simple expansion assumes that the steam only works when it expands in the cylinder, and the exhaust steam is released directly into the atmosphere or enters a special condenser. In this case, the residual heat of the steam can be used, for example, for heating a room or a vehicle, as well as for preheating the water entering the boiler.
Compound
During the expansion process in the cylinder of the high-pressure machine, the temperature of the steam drops in proportion to its expansion. Since there is no heat exchange in this case (adiabatic process), it turns out that steam enters the cylinder with a higher temperature than it leaves. Such temperature fluctuations in the cylinder lead to a decrease in the efficiency of the process.
One of the methods of dealing with this temperature difference was proposed in 1804 by the English engineer Arthur Wolfe, who patented Wolfe High Pressure Compound Steam Machine... In this machine, high-temperature steam from a steam boiler was fed into a high-pressure cylinder, and after that, the steam exhausted in it with a lower temperature and pressure entered the low-pressure cylinder (or cylinders). This reduced the temperature difference in each cylinder, which in general reduced temperature losses and improved the overall efficiency of the steam engine. Low pressure steam had a larger volume and therefore required a larger cylinder volume. Therefore, in compound machines, low-pressure cylinders had a larger diameter (and sometimes longer) than high-pressure cylinders.
This is also known as double expansion because the expansion of steam occurs in two stages. Sometimes one high pressure cylinder was associated with two low pressure cylinders, resulting in three cylinders of approximately the same size. This arrangement was easier to balance.
Two-cylinder compounding machines can be classified as:
- Cross compound- The cylinders are located side by side, their steam conduits are crossed.
- Tandem compound- The cylinders are in series and use one stem.
- Corner compound- The cylinders are angled to each other, usually 90 degrees, and work on one crank.
After the 1880s, compound steam engines became widespread in manufacturing and transport and became practically the only type used on steamships. Their use on steam locomotives was not so widespread, as they turned out to be too difficult, partly due to the fact that the working conditions of steam engines on railway transport were difficult. Despite the fact that compound locomotives never became a mass phenomenon (especially in the UK, where they were very rare and not used at all after the 1930s), they gained some popularity in several countries.
Multiple extension
Simplified diagram of a triple expansion steam engine.
High pressure steam (red) from the boiler passes through the machine, leaving the condenser at low pressure (blue).
The logical development of the compound scheme was the addition of additional expansion stages to it, which increased the efficiency of the work. The result was a multiple expansion scheme known as triple or even quadruple expansion machines. These steam engines used a series of double-acting cylinders, the volume of which increased with each stage. Sometimes, instead of increasing the volume of low-pressure cylinders, an increase in their number was used, just like on some compound machines.
The image on the right shows the operation of a triple expansion steam engine. Steam flows through the car from left to right. The valve block of each cylinder is located to the left of the corresponding cylinder.
The emergence of this type of steam engines became especially relevant for the fleet, since the size and weight requirements for ship vehicles were not very strict, and most importantly, such a scheme made it possible to easily use a condenser that returns waste steam in the form of fresh water back to the boiler (use salted sea water to power the boilers was not possible). Ground-based steam engines usually did not have problems with water supply and therefore could discharge waste steam into the atmosphere. Therefore, such a scheme was less relevant for them, especially given its complexity, size and weight. The dominance of multiple expansion steam engines ended only with the emergence and widespread use of steam turbines. However, modern steam turbines use the same principle of dividing the flow into high, medium and low pressure cylinders.
Direct-flow steam machines
Direct-flow steam engines arose as a result of an attempt to overcome one disadvantage inherent in steam engines with traditional steam distribution. The fact is that steam in a conventional steam engine constantly changes its direction of movement, since the same window on each side of the cylinder is used for both inlet and outlet of steam. When the exhaust steam leaves the cylinder, it cools the walls and the steam distribution channels. Fresh steam, accordingly, spends a certain part of the energy on heating them, which leads to a drop in efficiency. Direct-flow steam engines have an additional port, which is opened by a piston at the end of each phase, and through which the steam leaves the cylinder. This increases the efficiency of the machine as the steam moves in one direction and the temperature gradient of the cylinder walls remains more or less constant. Single expansion straight-through machines show approximately the same efficiency as compound machines with conventional steam distribution. In addition, they can operate at higher speeds, and therefore, before the advent of steam turbines, they were often used to drive power generators that require high speed.
Direct-flow steam engines are available in both single and double acting.
Steam turbines
A steam turbine is a series of rotating discs mounted on a single axis, called a turbine rotor, and a series of alternating stationary discs fixed on a base, called a stator. The rotor discs have blades on the outside, steam is supplied to these blades and turns the discs. The stator discs have similar vanes, set at the opposite angle, which serve to redirect the steam flow to the following rotor discs. Each rotor disc and its corresponding stator disc are called a turbine stage. The number and size of stages of each turbine are selected in such a way as to maximize the use of the useful energy of the steam at the same speed and pressure that is supplied to it. The exhaust steam leaving the turbine enters the condenser. Turbines rotate at a very high speed, and therefore special reduction transmissions are usually used when transferring rotation to other equipment. In addition, turbines cannot change the direction of their rotation, and often require additional reverse mechanisms (sometimes additional stages of reverse rotation are used).
Turbines convert steam energy directly into rotation and do not require additional mechanisms for converting reciprocating motion into rotation. In addition, turbines are more compact than reciprocating machines and have a constant force on the output shaft. Because turbines are simpler in design, they generally require less maintenance.
Other types of steam engines
Application
Steam machines can be classified according to their application as follows:
Stationary machines
Steam hammer
Steam engine in an old sugar factory, Cuba
Stationary steam machines can be divided into two types according to the mode of use:
- Variable-speed machines, which include rolling mill machines, steam winches and the like, which must stop frequently and change direction of rotation.
- Power machines that rarely stop and should not change direction of rotation. These include power motors in power plants, as well as industrial motors used in factories, factories and cable railways before the widespread use of electric traction. Low power engines are used on marine models and in special devices.
The steam winch is essentially a stationary motor, but it is mounted on a base frame so that it can be moved. It can be fixed with a cable to the anchor and moved by its own traction to a new place.
Transport vehicles
Steam machines were used to drive different types vehicles, among them:
- Land vehicles:
- Steam car
- Steam tractor
- Steam excavator, and even
- Steam plane.
In Russia, the first operating steam locomotive was built by E. A. and M. E. Cherepanov at the Nizhne-Tagil plant in 1834 to transport ore. He developed a speed of 13 versts per hour and transported more than 200 poods (3.2 tons) of cargo. The length of the first railway was 850 m.
The advantages of steam engines
The main advantage of steam engines is that they can use almost any heat source to convert it into mechanical work. This distinguishes them from engines. internal combustion, each type of which requires the use of a specific type of fuel. This advantage is most noticeable when using nuclear energy, since a nuclear reactor is not able to generate mechanical energy, but only produces heat, which is used to generate steam that drives steam engines (usually steam turbines). In addition, there are other heat sources that cannot be used in internal combustion engines, such as solar energy. An interesting direction is the use of the energy of the temperature difference of the World Ocean at different depths.
Other types of external combustion engines, such as the Stirling engine, also have similar properties, which can provide very high efficiency, but are significantly larger in weight and size than modern types of steam engines.
Steam locomotives perform well at high altitudes, since their efficiency does not decrease due to low atmospheric pressure. Steam locomotives are still used today in the mountainous regions of Latin America, despite the fact that in the flat areas they have long been replaced by more modern types of locomotives.
In Switzerland (Brienz Rothhorn) and Austria (Schafberg Bahn), new dry steam locomotives have proven their worth. This type of steam locomotive was developed on the basis of the Swiss Locomotive and Machine Works (SLM) models, with many modern improvements such as the use of roller bearings, modern thermal insulation, combustion of light oil fractions, improved steam lines, etc. ... As a result, these locomotives have 60% lower fuel consumption and significantly lower maintenance requirements. The economic qualities of such locomotives are comparable to those of modern diesel and electric locomotives.
In addition, steam locomotives are significantly lighter than diesel and electric ones, which is especially important for mountain railways. The peculiarity of steam engines is that they do not need a transmission, transmitting power directly to the wheels.
Efficiency
Coefficient of performance (COP) heat engine can be defined as the ratio of useful mechanical work to the expended amount of heat contained in the fuel. The rest of the energy is released into the environment as heat. The efficiency of the heat engine is
The process of inventing the steam engine, as is often the case in technology, stretched out for almost a century, so the choice of the date for this event is rather arbitrary. However, no one denies that the breakthrough that led to the technological revolution was carried out by the Scotsman James Watt.
People thought about using steam as a working medium even in ancient times. However, only at the turn of the XVII-XVIII centuries. managed to find a way to do useful work with steam. One of the first attempts to put steam at the service of man was made in England in 1698: the machine of the inventor Savery was designed to drain mines and pump water. True, the invention of Savery was not yet an engine in the full sense of the word, since, apart from several valves that were manually opened and closed, there were no moving parts in it. Savery's machine worked as follows: first, a sealed tank was filled with steam, then the outer surface of the tank was cooled with cold water, which condensed the steam, and a partial vacuum was created in the tank. After that, water - for example, from the bottom of the mine - was sucked into the tank through the intake pipe and, after the next portion of steam was injected, was thrown out.
The first steam engine with a piston was built by the Frenchman Denis Papin in 1698. Water was heated inside a vertical cylinder with a piston, and the resulting steam pushed the piston upwards. When the steam cooled and condensed, the piston was pushed down by atmospheric pressure. Through a system of blocks, Papen's steam engine could drive various mechanisms, such as pumps.
A more perfect machine was built in 1712 by the English blacksmith Thomas Newcomen. As in the Papen machine, the piston moved in a vertical cylinder. Steam from the boiler entered the base of the cylinder and lifted the piston up. When cold water was injected into the cylinder, the vapor condensed, a vacuum was formed in the cylinder, and the piston sank down under the influence of atmospheric pressure. This reverse removed water from the cylinder and, by means of a chain connected to a rocker, moving like a swing, raised the pump rod. When the piston was at the lowest point of its stroke, steam entered the cylinder again, and with the help of a counterweight attached to the pump rod or on the rocker arm, the piston was raised to its original position. After that, the cycle was repeated.
The Newcomen machine has been in widespread use in Europe for over 50 years. In the 1740s, a machine with a cylinder 2.74 m long and 76 cm in diameter did the work in one day, which a team of 25 people and 10 horses, working in shifts, did in a week. And yet, its efficiency was extremely low.
The industrial revolution manifested itself most vividly in England, primarily in the textile industry. The mismatch between the supply of fabrics and the rapidly increasing demand has attracted the best design minds to the development of spinning and weaving machines. The names of Cartwright, Kay, Crompton, Hargreaves have forever entered the history of English technology. But the spinning and weaving machines they created needed a qualitatively new one, universal engine, which would continuously and evenly (this is what a water wheel could not provide) would drive the machines in a unidirectional rotational movement. It was here that the talent of the famous engineer, the "wizard from Greenock" James Watt, appeared in all its brilliance.
Watt was born in the Scottish town of Greenock in the family of a shipbuilder. While working as an apprentice in workshops in Glasgow, in the first two years, James acquired the qualifications of an engraver, a master in the manufacture of mathematical, geodetic, optical instruments, and various navigational instruments. On the advice of his uncle, a professor, James entered the local university as a mechanic. It was here that Watt began working on steam engines.
James Watt tried to improve Newcomen's steam-atmospheric engine, which, in general, was only suitable for pumping water. It was clear to him that the main drawback of the Newcomen machine was the alternating heating and cooling of the cylinder. In 1765, Watt came to the idea that a cylinder could be permanently hot if the steam was drained into a separate tank through a pipeline with a valve prior to condensation. In addition, Watt made several more improvements that finally turned the steam-atmospheric engine into a steam one. For example, he invented a hinge mechanism - "Watt's parallelogram" (so called because some of the links - levers that make up it form a parallelogram), which converted the reciprocating movement of the piston into the rotational movement of the main shaft. Now the looms could run continuously.
In 1776, Watt's car was tested. Its efficiency turned out to be twice that of the Newcomen machine. In 1782, Watt built the first universal double-acting steam engine. Steam entered the cylinder alternately from one side of the piston, then from the other. Therefore, the piston made both a working and a reverse stroke with the help of steam, which was not in previous machines. Since the piston rod was pulling and pushing in a double-acting steam engine, the old chain-and-rocker drive system, which only reacted to pull, had to be redesigned. Watt developed a system tied rods and used a planetary gear mechanism to convert the reciprocating motion of the piston rod into rotary motion, using a heavy flywheel, a centrifugal speed regulator, a disc valve and a pressure gauge to measure vapor pressure. Watt's patented "rotary steam engine" was first widely used in spinning and weaving mills, and later in other industrial enterprises. Watt's engine was suitable for any machine, and the inventors of self-propelled mechanisms were not slow to take advantage of this.
Watt's steam engine was truly the invention of the century, and the beginning of the Industrial Revolution. But the inventor didn't stop there. Neighbors more than once watched in amazement as Watt chased horses through the meadow, pulling specially selected weights. This is how the unit of power appeared - Horsepower, which subsequently received universal recognition.
Unfortunately, financial difficulties forced Watt, already in adulthood, to conduct geodetic surveys, work on the construction of canals, build ports and marinas, and finally go to an economically enslaving alliance with entrepreneur John Rebeck, who soon suffered a complete financial collapse.
On April 12, 1933, William Besler took off from the Oakland Municipal Airfield in California on a steam-powered aircraft.
The newspapers wrote:
“The takeoff was normal in every way, except for the absence of noise. In fact, when the plane had already detached from the ground, it seemed to observers that it had not yet picked up sufficient speed. At full power, the noise was no more noticeable than when the plane was gliding. All that could be heard was the whistle of the air. When running on full steam, the propeller produced only a little noise. It was possible to distinguish through the noise of the propeller the sound of the flame ... 
When the plane went to land and crossed the border of the field, the propeller stopped and started slowly in the opposite direction with the help of reverse shifting and the subsequent small opening of the throttle. Even with very slow reverse rotation of the propeller, the reduction became noticeably steeper. Immediately after touching the ground, the pilot gave full reverse, which, together with the brakes, quickly stopped the car. The short range was especially noticeable in this case, as the weather was calm during the test, and usually the landing range reached several hundred feet. "
At the beginning of the 20th century, records of the height reached by aircraft were set almost annually: 
The stratosphere promised considerable benefits for flight: lower air resistance, constancy of winds, lack of cloud cover, stealth, and inaccessibility for air defense. But how to take off to an altitude of, for example, 20 kilometers?
[Gasoline] engine power drops faster than air density. 
At an altitude of 7000 m, the motor power is reduced by almost three times. In order to improve the high-altitude qualities of aircraft, at the end of the imperialist war, attempts were made to use supercharging, in the period 1924-1929. blowers are being introduced into production even more. However, it is becoming increasingly difficult to maintain the power of an internal combustion engine at altitudes above 10 km.
In an effort to raise the "height limit", designers of all countries more and more often turn their eyes to the steam engine, which has a number of advantages as a high-altitude engine. Some countries, such as Germany, pushed on this path and strategic considerations, namely, the need in the event of a major war to achieve independence from imported oil.
In recent years, numerous attempts have been made to install a steam engine on an aircraft. The rapid growth of the aviation industry on the eve of the crisis and monopoly prices for its products made it possible not to rush to implement experimental work and accumulated inventions. These attempts, which took on a special scale during the economic crisis of 1929-1933. and the subsequent depression - not an accidental phenomenon for capitalism. In the press, especially in America and France, reproaches were often thrown at large concerns about their agreements on artificially delaying the implementation of new inventions.
Two directions have emerged. One is represented in America by Besler, who installed a conventional piston engine on an aircraft, the other is due to the use of a turbine as aircraft engine and is mainly associated with the work of German designers.
The Besler brothers took Doble's piston steam engine for a car as a basis and installed it on a Travel-Air biplane [a description of their demonstration flight is given at the beginning of the post].
Video of that flight:
The machine is equipped with a reversing mechanism, with which you can easily and quickly change the direction of rotation of the machine shaft, not only in flight, but also when the aircraft is landing. The engine, in addition to the propeller, drives through coupling sleeve a fan that blows air into the burner. At the start, they use a small electric motor. 
The machine developed a power of 90 hp, but under the conditions of the well-known forcing of the boiler, its power can be increased to 135 hp. with.
Steam pressure in the boiler is 125 at. The steam temperature was maintained at about 400-430 °. In order to maximize the automation of the boiler operation, a normalizer or device was used, with the help of which water was injected at a known pressure into the superheater as soon as the steam temperature exceeded 400 °. The boiler was equipped with a feed pump and steam drive, as well as primary and secondary feed water heaters heated by waste steam. 
Two condensers were installed on the plane. The more powerful one was redesigned from the OX-5 engine radiator and installed on top of the fuselage. The less powerful is made from the condenser of Doble's steam car and is located under the fuselage. The capacity of the condensers, it was claimed in the press, was insufficient to operate a steam engine at full throttle without venting into the atmosphere "and approximately corresponded to 90% of the cruising power." Experiments have shown that with a consumption of 152 liters of fuel, 38 liters of water were required.
The total weight of the aircraft's steam plant was 4.5 kg per liter. with. Compared to the OX-5 engine running on this aircraft, this gave an extra weight of 300 pounds (136 kg). There is no doubt that the weight of the entire installation could be significantly reduced by lightening the motor parts and capacitors.
The fuel was gas oil. The press claimed that "no more than 5 minutes elapsed between turning on the ignition and starting at full speed."
Another direction in the development of a steam power plant for aviation is associated with the use of a steam turbine as an engine.
In 1932-1934. information about an original steam turbine for an aircraft designed in Germany at the Klinganberg electric plant has penetrated into the foreign press. The chief engineer of this plant, Huetner, was named its author.
The steam generator and the turbine, together with the condenser, were here combined into one rotating unit having a common housing. Hütner notes: “The engine represents a power plant, a distinctive characteristic feature which consists in the fact that a rotating steam generator forms one structural and operational whole with a turbine and a condenser rotating in the opposite direction ”.
The main part of the turbine is a rotating boiler, formed from a series of V-shaped tubes, with one elbow of these tubes connected to a feedwater header, the other to a steam collector. The boiler is shown in FIG. 143. 
The tubes are located radially around the axis and rotate at a speed of 3000-5000 rpm. The water entering the tubes rushes under the action of centrifugal force into the left branches of the V-shaped tubes, the right knee of which acts as a steam generator. The left elbow of the pipes has fins that are heated by the flame from the nozzles. Water, passing by these ribs, turns into steam, and under the action of centrifugal forces arising from the rotation of the boiler, the steam pressure increases. The pressure is automatically regulated. The difference in density in both branches of the tubes (steam and water) gives a variable level difference, which is a function of the centrifugal force, and therefore the speed of rotation. A diagram of such a unit is shown in Fig. 144. 
A feature of the boiler design is the arrangement of the tubes, in which, during rotation, a vacuum is created in the combustion chamber, and thus the boiler acts as a suction fan. Thus, according to Hütner, "the rotation of the boiler determines simultaneously its power supply, the movement of hot gases, and the movement of cooling water." 
It takes only 30 seconds to start the turbine. Hüthner hoped to achieve a boiler efficiency of 88% and a turbine efficiency of 80%. The turbine and boiler need starting motors to start.
In 1934, a message flashed in the press about the development of a project for a large aircraft in Germany, equipped with a turbine with a rotating boiler. Two years later, the French press claimed that a special aircraft had been built by the military department in Germany under conditions of great secrecy. A steam power plant of the Hüthner system with a capacity of 2500 liters was designed for it. with. The length of the aircraft is 22 m, the wingspan is 32 m, the flight weight (approximate) is 14 t, the absolute ceiling of the aircraft is 14,000 m, the flight speed at an altitude of 10,000 m is 420 km / h, the ascent to an altitude of 10 km is 30 minutes.
It is quite possible that these press reports are greatly exaggerated, but there is no doubt that the German designers are working on this problem, and the upcoming war may bring unexpected surprises here.
What is the advantage of a turbine over an internal combustion engine?
1. The absence of reciprocating motion at high rotational speeds allows the turbine to be made rather compact and smaller than modern powerful aircraft engines.
2. An important advantage the relative quietness of the operation of the steam engine is also important, which is important both from the point of view of the military and from the point of view of the possibility of lightening the aircraft due to soundproofing equipment on passenger aircraft.
3. A steam turbine, unlike internal combustion engines, which are almost non-overloading, can be overloaded for a short period up to 100% at a constant speed. This advantage of the turbine makes it possible to shorten the takeoff run of the aircraft and facilitate its ascent into the air.
4. The simplicity of the design and the absence of a large number of moving and operating parts are also an important advantage of the turbine, making it more reliable and durable compared to internal combustion engines.
5. The absence of a magneto on the steam plant, the operation of which can be influenced by radio waves, is also essential.
6. The ability to use heavy fuel (oil, fuel oil), in addition to economic advantages, provides a greater fire safety of the steam engine. In addition, it is possible to heat the aircraft.
7. The main advantage of the steam engine is that it maintains its rated power while rising to the height.
One of the objections to a steam engine comes mainly from aerodynamics and comes down to the size and cooling capabilities of the condenser. Indeed, a steam condenser has a surface area 5-6 times larger than that of a water radiator in an internal combustion engine.
That is why, in an effort to reduce the drag of such a capacitor, the designers came up with the placement of the capacitor directly over the surface of the wings in the form of a continuous row of tubes, following exactly the contour and profile of the wing. In addition to imparting significant rigidity, this will also reduce the risk of icing the aircraft.
There are, of course, a whole series of other technical difficulties in operating a turbine on an airplane.
- The behavior of the nozzle at high altitudes is unknown.
- To change the fast load of the turbine, which is one of the conditions for the operation of an aircraft engine, it is necessary to have either a water supply or a steam collector.
- The development of good automatic device to regulate the turbine.
- The gyroscopic effect of a rapidly rotating turbine on an airplane is also unclear.
Nevertheless, the successes achieved give reason to hope that in the near future the steam power plant will find its place in the modern air fleet, especially in commercial transport aircraft, as well as in large airships. The hardest part in this area has already been done, and practicing engineers will be able to achieve ultimate success.
Throughout its history, the steam engine has had many variations of embodiment in metal. One of such incarnations was the rotary steam engine of mechanical engineer N.N. Tverskoy. This steam rotary engine (steam engine) was actively used in various fields of technology and transport. In the Russian technical tradition of the 19th century, such a rotary engine was called a rotary machine. The engine was distinguished by its durability, efficiency and high torque. But with the advent of steam turbines, it was forgotten. Below are archival material raised by the author of this site. The materials are quite extensive, therefore, so far only a part of them is presented here.
Test scrolling with compressed air (3.5 atm) steam rotary engine.
The model is designed for 10 kW of power at 1500 rpm at a steam pressure of 28-30 atm.
At the end of the 19th century, steam engines - "N. Tverskoy's rotary locomotives" were forgotten because piston steam engines turned out to be simpler and more technologically advanced in production (for industries of that time), and steam turbines gave more power.
But the remark regarding steam turbines is valid only in their large mass and dimensions. Indeed, with a power of more than 1.5-2 thousand kW, multi-cylinder steam turbines outperform rotary steam engines in all respects, even with the high cost of turbines. And at the beginning of the 20th century, when ships power plants and power units power plants began to have a capacity of many tens of thousands of kilowatts, then only turbines could provide such opportunities.
BUT - steam turbines have another drawback. When scaling their mass-dimensional parameters downward, the performance characteristics of steam turbines deteriorate sharply. The power density significantly decreases, the efficiency decreases, while the high cost of manufacturing and high revs the main shaft (the need for a gearbox) - remain. That is why - in the area of capacities less than 1.5 thousand kW (1.5 MW), it is almost impossible to find a steam turbine efficient in all parameters, even for a lot of money ...
That is why a whole bunch of exotic and little-known designs has appeared in this power range. But more often they are also expensive and ineffective ... Screw turbines, Tesla turbines, axial turbines, etc.
But for some reason everyone forgot about steam "rotor machines" - rotary steam engines. And meanwhile - these steam engines are many times cheaper than any blade and screw mechanisms (I say this with knowledge of the matter, as a person who has already made more than a dozen of such machines with his own money). At the same time, N. Tverskoy's steam rotor machines have a powerful torque from the smallest revolutions, have an average speed of the main shaft at full speed from 1000 to 3000 rpm. Those. such machines, even for an electric generator, even for a steam car (a car - a truck, a tractor, a tractor) - will not require a gearbox, coupling, etc., but will directly connect with their shaft with a dynamo, wheels of a steam car, etc.
So - in the form of a rotary steam engine - the system of "N. Tverskoy's rotary machine", we have a universal steam engine that will perfectly generate electricity from a solid fuel boiler in a remote forestry or taiga village, in a field mill or generate electricity in a boiler house in a rural settlement or "spinning" on waste of process heat (hot air) at a brick or cement plant, in a foundry, etc.
All such heat sources have a power of less than 1 MW, therefore, conventional turbines are of little use here. And the general technical practice does not yet know other machines for heat recovery by converting the pressure of the obtained steam into operation. So this heat is not utilized in any way - it is simply lost stupidly and irretrievably.
I have already created a "steam rotor machine" to drive an electric generator of 3.5 - 5 kW (depending on the pressure in the steam), if everything goes as planned, then soon there will be a machine of 25 and 40 kW. Just what you need to provide cheap electricity from a solid fuel boiler or process heat waste to a rural estate, a small farm, a field camp, etc., etc.
In principle, rotary motors are well scaled upwards, therefore, by fitting many rotor sections onto one shaft, it is easy to multiply the power of such machines by simply increasing the number of standard rotor modules. That is, it is quite possible to create rotary steam machines with a capacity of 80-160-240-320 and more kW ...
But, in addition to medium and relatively large steam power plants, steam power schemes with small steam rotary engines will be in demand in small power plants.
For example, one of my inventions - "Camping and tourist electric generator on local solid fuel."
Below is a video where a simplified prototype of such a device is tested.
But a small steam engine is already cheerfully and energetically turning its electric generator and, using wood and other fossil fuel, produces electricity.
The main direction of commercial and technical application rotary steam engines (rotary steam engines) are the generation of cheap electricity from cheap solid fuels and combustible waste. Those. small energy - distributed power generation on steam rotary engines. Imagine how a rotary steam engine will perfectly fit into the operation of a sawmill-sawmill, somewhere in the Russian North or in Siberia (Far East) where there is no central power supply, electricity is expensively supplied by a diesel generator using diesel fuel imported from afar. But the sawmill itself produces at least half a ton of chips per day - sawdust - slabs, which have nowhere to go ...
Such wood waste is a direct road to the boiler furnace, the boiler produces high-pressure steam, the steam drives the rotary steam engine and it turns the electric generator.
In the same way, you can burn millions of tons of crop waste from agriculture and so on, unlimited in volume. And there is also cheap peat, cheap thermal coal, and so on. The author of the site calculated that the cost of fuel when generating electricity through a small steam power plant (steam engine) with a steam rotary engine with a power of 500 kW will be from 0.8 to 1,
2 rubles per kilowatt.
Another interesting application of a rotary steam engine is the installation of such a steam engine on a steam vehicle. The truck is a tractor steam vehicle with powerful torque and cheap solid fuel - a very useful steam engine in agriculture and forestry. With the use of modern technologies and materials, as well as the use of the "Organic Rankine Cycle" in the thermodynamic cycle, the effective efficiency can be increased to 26-28% using cheap solid fuel (or inexpensive liquid fuel, such as "heating oil" or waste engine oil). Those. truck - tractor with steam engine
and a rotary steam engine with a capacity of about 100 kW, it will consume about 25-28 kg of thermal coal per 100 km (cost 5-6 rubles per kg) or about 40-45 kg of wood chips (take away the price in the North for nothing) ...
There are many more interesting and promising areas of application of the rotary steam engine, but the size of this page does not allow considering all of them in detail. As a result, the steam engine can still take a very prominent place in many areas of modern technology and in many sectors of the national economy.
START-UP OF A STEAM POWER GENERATOR WITH A STEAM ENGINE
May -2018 After lengthy experiments and prototypes, a small high-pressure boiler was made. The boiler is pressurized at 80 atm of pressure, so it will keep the operating pressure of 40-60 atm without difficulty. Launched into operation with a prototype of a steam axial piston engine of my design. Works great - watch the video. For 12-14 minutes from ignition on wood, it is ready to give high pressure steam.
Now I am starting to prepare for the piece production of such installations - a high-pressure boiler, a steam engine (rotary or axial piston), a condenser. The units will operate in a closed circuit with a water-steam-condensate turnover.
The demand for such generators is very high, because 60% of the territory of Russia does not have a central power supply and is powered by diesel generation. And the price of diesel fuel is growing all the time and has already reached 41-42 rubles per liter. And even where there is electricity, energy companies raise tariffs, and they require a lot of money to connect new capacities.
