The accumulation of new practical knowledge in the 16th-17th centuries led to unheard-of upsurges of human thought. Water and wind wheels rotate machine tools, set bellows in motion, help metallurgists lift ore from mines, that is, where human hands cannot cope with hard work, the energy of water and wind comes to their aid. The main technological achievements of that time were due not so much to scientists and science as to the painstaking work of skilled inventors. Achievements in mining technology, in the extraction of various ores and minerals were especially great. It was necessary to lift the mined ore or coal from the mine, pump out the groundwater that flooded the mine all the time, constantly supply air to the mine, and a lot of a wide variety of labor-intensive work was required so that mining would not stop. Thus, the developing industry imperiously demanded more and more energy, and at that time it was mainly water wheels that could provide it. They have already learned to build powerful enough. In connection with the increase in the power of the wheels, metal has become increasingly used for shafts and some other parts. In France, on the Seine River in 1682, master R. Salem, under the leadership of A. de Ville, built the largest installation for that time, consisting of 13 wheels with a diameter of 8 m, which served to drive more than 200 pumps that supplied water to a height of over 160 m , and providing water to fountains in Versailles and Marly. The first cotton mills used hydraulic motor. Arkwright's spinning machines were powered by water from the beginning. However, water wheels could only be installed on a river, preferably full-flowing and fast. And if a textile or metalworking factory could still be built on the banks of the river, then ore deposits or coal seams had to be developed only in places of occurrence. And for pumping out the groundwater that flooded the mine and lifting the mined ore or coal to the surface, energy was also needed. Therefore, in the mines remote from the rivers, it was necessary to use only the power of animals.
The owner of an English mine in 1702 had to keep 500 horses to operate the pumps that pump water out of the mine, which was very unprofitable.
The developing industry needed powerful engines new type, which would allow you to create production anywhere. The first impetus for the creation of new engines that can work anywhere, whether there is a river nearby or not, was precisely the need for pumps and lifts in metallurgy and mining.
The ability of steam to produce mechanical work has long been known to man. The first traces of the actual intelligent use of steam in mechanics are mentioned in 1545 in Spain, when a naval captain
Blasco de Garay designed a machine with which he set in motion the side paddle wheels of the ship and which, by order of Charles V, was first tested in the harbor of Barcelona when transporting 4,000 quintals of cargo by ship three nautical miles in two hours. The inventor was rewarded, but the machine itself was left without use and was consigned to oblivion.
At the end of the 17th century, in countries with the most developed manufactory production, elements of new machine technology were born using the properties and power of water vapor.
Early attempts to create a heat engine were associated with the need to pump water from mines where fuel was mined. In 1698, the Englishman Thomas Savery, a former miner and then captain of the merchant marine, first proposed pumping water using a steam water lift. The patent received by Savery read: "This new invention of raising water and getting propulsion for all kinds of production by means of the motive power of fire is of great importance for the drying of mines, the water supply of cities, and the production of motive power for factories of all kinds that cannot use water power or the constant work of wind." The Severi water lift worked on the principle of sucking water at the expense of atmospheric pressure into the chamber, where a rarefaction was created when the steam condensed with cold water. Severi's steam engines were extremely uneconomical and inconvenient to operate, they could not be adapted to drive machine tools, they consumed a huge amount of fuel, the coefficient useful action they were not higher than 0.3%. However, the demand for pumping water from the mines was so great that even these bulky pump-type steam engines gained some popularity.
Thomas Newcomen (1663-1729) - English inventor, blacksmith by profession. Together with the tinker J. Cowley, he built a steam pump, the experiments to improve which lasted about 10 years, until he began to work properly. The Newcomen steam engine was not a universal engine. The merit of Newcomen is that he was one of the first to realize the idea of using steam to obtain mechanical work. The Society of British Technologists bears his name. In 1711, Newcomen, Cowley, and Savery formed the "Company of Owners of Rights to Invent Apparatus for Raising Water by Fire." As long as these inventors were patent holders for "using the power of fire", all their work on the manufacture of steam engines was carried out in the strictest confidence. The Swede Triwald, who was involved in setting up Newcomen's machines, wrote: “... the inventors Newcomen and Cowley were very suspicious and careful to keep the secret of building and using their invention for themselves and their children. The Spanish envoy to the English court, who came from London with a large retinue of foreigners to look at the new invention, was not even allowed into the room in which the machines were located. But in the 20s of the XVIII century, the patent expired and many engineers took up the manufacture of water-lifting installations. Literature appeared that described these settings.
The process of distribution of universal steam engines in England by the beginning of the 19th century. confirms the enormous significance of the new invention. If for a decade from 1775 to 1785. 66 cars were built double action with a total power of 1288 hp, then from 1785 to 1795. 144 double-acting machines with a total power of 2009 hp were already created, and in the next five years - from 1795 to 1800. - 79 cars with a total capacity of 1296 hp
Actual application in industry steam engine began in 1710, when the English workers Newcomen and Cowley first built a steam engine that powered a pump installed in a mine to pump water out of it.
However, Newcomen's machine was not a steam engine in the modern sense of the word, since the driving force in it was still not water vapor, but atmospheric air pressure. Therefore, this machine was called "atmospheric". Although in the machine, water vapor served, as in Severi's machine, mainly to create a vacuum in the cylinder, a movable piston was already proposed here - the main part of the modern steam engine.
On fig. Figure 4.1 shows the Newcomen-Cowley steam lift. When lowering the sucker rod 1 and load 2, the piston 4 rose and steam entered the cylinder 5 through the open tap 7 from the boiler 8, the pressure of which was slightly higher than atmospheric. Steam served to partially lift the piston in the cylinder, open at the top, but its main role was to create a vacuum in it. For this purpose, when the piston of the machine reached its upper position, tap 7 was closed, and cold water was injected from tank 3 through tap 6 into the cylinder. The water vapor quickly condensed, and atmospheric pressure returned the piston to the bottom of the cylinder, lifting the sucker rod. Condensate was discharged from the cylinder by a tube9, the piston was raised again due to the supply of steam, and the process described above was repeated. Newcomen's machine is a batch engine.
Newcomen's steam engine was more perfect than Savery's, easier to operate, more economical and productive. However, the machines of the first releases worked very uneconomically, to create power in one horsepower up to 25 kg of coal was burned per hour, that is, the efficiency was about 0.5%. The introduction of automatic distribution of steam and water flows simplified the maintenance of the machine, the piston stroke time decreased to 12–16 minutes, which reduced the dimensions of the machine and made the design cheaper. Despite the high fuel consumption, this type of machine quickly became widespread. Already in the twenties of the XVIII century, these machines worked not only in England, but also in many European countries - in Austria, Belgium, France, Hungary, Sweden, they were used for almost a century in the coal industry and for supplying water to cities. In Russia, the first Newcomen steam-atmospheric machine was installed in 1772 in Kronstadt to pump water from the dock. The prevalence of Newcomen machines is evidenced by the fact that the last machine of this type in England was dismantled only in 1934.
Ivan Ivanovich Polzunov (1728-1766) is a talented Russian inventor who was born in the family of a soldier. In 1742, the mechanic of the Yekaterinburg plant, Nikita Bakharev, needed quick-witted students. The choice fell on the fourteen-year-olds I. Polzunov and S. Cheremisinov, who were still studying at the Arithmetic School. Theoretical training at school gave way to practical familiarization with the operation of the most modern machines and installations of the Yekaterinburg plant in Russia at that time. In 1748, Polzunov was transferred to Barnaul to work at the Kolyvano-Voskresensky factories. After an independent study of books on metallurgy and mineralogy in April 1763, Polzunov proposed a project of a completely original steam engine, which differed from all machines known at that time in that it was designed to drive blower bellows and was a unit continuous action. In his memorandum on the "fire machine" dated April 26, 1763, Polzunov, in his own words, wanted " ... by the addition of a fiery machine stop the water management and, for these cases, completely destroy it, and instead of dams for the movable foundation of the plant, establish it so that it is able to all the burdens imposed on itself, which are usually necessary for fanning the fire, carry and, at will ours, what will be necessary, to correct. And then he wrote: “In order to achieve this glory (if the forces allow) for the Fatherland, and so that for the benefit of the whole people, due to the great knowledge about the use of things that are still not very familiar (following the example of other sciences), introduce into the custom. In the future, the inventor dreamed of adapting the machine for other needs. Project I.I. Polzunov was introduced to the royal office in St. Petersburg. The decision of Catherine II was as follows: “Her Imperial Majesty is not only Polzunov, mercifully pleased to be, but for the greatest encouragement she deigned to command: welcome Evo, Polzunov, to the mechanics with the rank and salary of a lieutenant captain, and give him 400 rubles as a reward” .
Newcomen's machines, which worked perfectly as water-lifting devices, could not satisfy the urgent need for a universal engine. They only paved the way for the creation of universal continuous steam engines.
At the initial stage of the development of steam engines, it is necessary to single out the “fiery machine” of the Russian mining master Polzunov. The engine was intended to drive the mechanisms of one of the smelting furnaces of the Barnaul plant.
According to Polzunov's project (Fig. 4.2), steam from the boiler (1) was supplied to one, say, left cylinder (2), where it raised the piston (3) to its highest position. Then a jet of cold water (4) was injected from the tank into the cylinder, which led to the condensation of steam. As a result of atmospheric pressure on the piston, it descended, while in the right cylinder, as a result of steam pressure, the piston rose. Water and steam distribution in the Polzunov machine was carried out by a special automatic device(5). The continuous working force from the pistons of the machine was transmitted to a pulley (6) mounted on a shaft, from which the movement was transmitted to the water and steam distribution device, the feed pump, and also to the working shaft, from which the blower bellows were set in motion.
Polzunov's engine belonged to the "atmospheric" type, but in it the inventor first introduced the summation of the work of two cylinders with pistons for one common shaft, which ensured a more even running of the engine. When one of the cylinders was on Idling, the other had a working move. The engine had automatic steam distribution and for the first time was not directly connected to working machine. I.I. Polzunov created his car in extremely difficult conditions, with his own hands, without necessary funds and special machines. He did not have skilled craftsmen at his disposal: the plant management seconded four students to Polzunov and allocated two retired workers. The ax and other simple tools used in the manufacture of then conventional machines were of little use here. Polzunov had to independently design and build new equipment for his invention. Construction big car, about 11 meters high, immediately from the sheet, not even tested on a model, without specialists, it required a huge effort. The car was built, but on May 27, 1766, I.I. Polzunov died of transient consumption, not having lived a week before the tests of the "big machine". The machine itself, tested by Polzunov's students, which not only paid for itself, but also brought profit, worked for 2 months, did not receive further improvement, and after a breakdown was abandoned and forgotten. After the Polzunov engine, half a century passed before steam engines began to be used in Russia.
James Watt - English inventor, creator of the universal steam engine, member of the Royal Society of London - was born in Greenock, Scotland. Since 1757, he worked as a mechanic at the University of Glasgow, where he got acquainted with the properties of water vapor and conducted research on the dependence of the temperature of saturated steam on pressure. In 1763-1764, while adjusting the model of Newcomen's steam engine, he proposed to reduce steam consumption by separating the steam condenser from the cylinder. From that time on, his work began on improving steam engines, researching the properties of steam, building new machines, etc., which continued throughout his life. On Watt's monument in Westminster Abbey, the inscription is carved: "... applying the power of creative genius to the improvement of the steam engine, he expanded the productivity of his country, increased the power of man over nature and took an outstanding place among the most famous men of science and the true benefactors of mankind." In search of funds for the construction of his engine, Watt began to dream of a profitable job outside of England. In the early 70s, he told his friends that "he was tired of the fatherland," and seriously started talking about moving to Russia. The Russian government offered the English engineer "an occupation according to his taste and knowledge" and with an annual salary of 1,000 pounds sterling. Watt's departure for Russia was prevented by a contract that he concluded in 1772 with the capitalist Bolton, the owner of a machine-building enterprise in Soho near Birmingham. Bolton had long known about the invention of a new "fiery" machine, but hesitated to subsidize its construction, doubting the practical value of the machine. He hurried to conclude an agreement with Watt only when there was a real threat of the inventor's departure to Russia. The agreement linking Watt to Bolton proved to be very effective. Bolton proved to be an intelligent and far-sighted man. He did not stint on the cost of building the machine. Bolton realized that the genius of Watt, freed from the petty, exhausting concern for a piece of bread, would unfold in full power and enrich the enterprising capitalist. In addition, Bolton himself was a major mechanical engineer. Watt's technical ideas also captivated him. The plant in Soho was famous for its first-class equipment for those times, and had skilled workers. Therefore, Watt enthusiastically accepted Bolton's offer to set up the production of steam engines of a new design at the plant. From the beginning of the 70s until the end of his life, Watt remained the chief mechanic of the plant. At the end of 1774, the Soho factory built the first double-acting machine.
Newcomen's machine was greatly improved over the century of its existence, but remained "atmospheric" and did not meet the needs of the rapidly growing technology of manufacturing production, which required the organization of rotational movement at high speed.
The search for many inventors was aimed at achieving the goal. In England alone, during the last quarter of the 18th century, more than a dozen patents were issued for universal engines of the most different systems. However, only James Watt managed to offer the industry a universal steam engine.
Watt began his work on the steam engine almost simultaneously with Polzunov, but under different conditions. In England at this time, industry was booming. Watt was actively supported by Bolton, the owner of several factories in England, who later became his partner, Parliament, and had the opportunity to use highly qualified engineering personnel. In 1769, Watt patented a steam engine with a separate condenser, and then the use of excess steam pressure in the engine, which significantly reduced fuel consumption. Watt was rightfully the creator of the steam piston engine.
On fig. 4.3, a diagram of one of Watt's first steam engines is shown. The steam boiler 1 is connected with the piston cylinder 3 by a steam pipeline 2 through which steam is periodically admitted into the upper cavity above the piston 4 and into the lower cavity below the piston of the cylinder. These cavities are connected to the condenser by a pipe5, where the exhaust steam is condensed with cold water and a vacuum is created. The machine has a balancer 6, which connects the piston with a crankshaft with the help of a connecting rod 7, at the end of which a flywheel is mounted 8.
For the first time, the principle of double action of steam was applied in the machine, which consists in the fact that fresh steam is admitted into the cylinder of the machine alternately into the chambers on both sides of the piston. Watt's introduction of the principle of steam expansion consisted in the fact that fresh steam was let into the cylinder only for part of the piston stroke, then the steam was cut off, and further movement The piston was carried out due to the expansion of steam and the drop in its pressure.
Thus, in Watt's machine, the decisive driving force was not atmospheric pressure, but the elasticity of the high-pressure steam that sets the piston in motion. The new principle of steam operation required a complete change in the design of the machine, especially the cylinder and steam distribution. To eliminate steam condensation in the cylinder, Watt first introduced a steam jacket of the cylinder, with the help of which he began to heat its working walls with steam, and insulated the outer side of the steam jacket. Since Watt could not use a connecting rod-crank mechanism in his machine to create a uniform rotational movement (a protective patent was taken for such a transmission by the French inventor Picard), in 1781 he took out a patent for five ways to convert a rocking motion into a continuous rotational one. At first, for this purpose, he used a planetary, or solar, wheel. Finally, Watt introduced a centrifugal speed controller to change the amount of steam supplied to the cylinder of the machine with a change in the number of revolutions. Thus, Watt, in his steam engine, laid down the basic principles of the design and operation of a modern steam engine.
Watt's steam engines ran on saturated steam low pressure 0.2–0.3 MPa, with a small number of revolutions per minute. Steam engines thus modified gave excellent results, reducing the consumption of coal per hp / h (horsepower per hour) several times compared with Newcomen's machines, and ousted the water wheel from the mining industry. In the mid 80s of the XVIII century. The design of the steam engine was finally developed, and the double-acting steam engine became a universal heat engine that found wide application in almost all sectors of the economy in many countries. In the 19th century, shaft lifting steam power plants, steam power blowers, rolling steam power plants, steam hammers, steam pumps, etc., became widespread.
Further increase in efficiency The steam power plant was achieved by Watt's contemporary Arthur Wolf in England by introducing multiple expansion of steam in succession in 2, 3 and even 4 steps, while the steam passed from one cylinder of the machine to another.
The rejection of the balancer and the use of multiple steam expansion led to the creation of new constructive forms of machines. Double-expansion engines began to take shape in the form of two cylinders - a high-pressure cylinder (HPC) and a low-pressure cylinder (LPC), which received the exhaust steam after the HPC. The cylinders were located either horizontally (compound machine, Fig. 4.4, a), or sequentially, when both pistons are seated on a common rod (tandem machine, Fig. 4.4, b).
Of great importance for increasing efficiency. steam engines began to use superheated steam with a temperature of up to 350 ° C in the middle of the 19th century, which made it possible to reduce fuel consumption to 4.5 kg per hp / h. The use of superheated steam was first proposed by the French scientist G.A. Girnom.
Born into a working-class family, George Stephenson (1781–1848) worked in the Newcastle coal mines where his father and grandfather also worked. He did a lot of self-education, studied physics, mechanics and other sciences, was interested in inventive activity. Stephenson's outstanding abilities led him to the post of mechanic, and in 1823 he was appointed chief engineer of the company for the construction of the first public railway Stockton-Darlington; this opened up great opportunities for him to design and inventive work.
In Russia, the first steam locomotives were built by Russian mechanics and inventors Cherepanovs - Efim Alekseevich (father, 1774–1842) and Miron Efimovich (son, 1803–1849), who worked at the Nizhny Tagil factories and were former serfs of the Demidovs factory owners. Cherepanovs through self-education became educated people, they visited the factories of St. Petersburg and Moscow, England and Sweden. For inventive activity, Miron Cherepanov and his wife were given freedom in 1833. Efim Cherepanov and his wife were given freedom in 1836. The Cherepanovs created about 20 different steam engines that worked at the Nizhny Tagil factories.
High steam pressure for steam engines was first used by Oliver Evans in America. This resulted in a further reduction in fuel consumption of up to 3 kg per hp/h. Later, steam locomotive designers began to use multi-cylinder steam engines, overpressure steam, and a reversing device.
In the XVIII century. there was a completely understandable desire to use the steam engine for land and water transport. In the development of steam engines, an independent direction was locomotives - mobile steam power plants. The first installation of this type was developed by the English builder John Smith. In fact, the development of steam transport began with the installation of fire tubes in fire-tube boilers, which significantly increased their steam output.
Many attempts were made to develop steam locomotives - steam locomotives, operating models were built (Fig. 4.5, 4.6). Of these, the Rocket steam locomotive built by the talented English inventor George Stephenson (1781–1848) in 1825 stands out (see Fig. 4.6, a, b).
The Rocket was not the first steam locomotive designed and built by Stephenson, but this one was superior in many respects and was voted the best locomotive at a special exhibition at Rayhill and recommended for the new Liverpool-Manchester railway, which became exemplary at that time. In 1823, Stephenson organized the first locomotive plant in Newcastle. In 1829, a competition was organized in England for the best steam locomotive, the winner of which was the machine of J. Stephenson. His steam locomotive "Rocket", developed on the basis of a fire boiler, with a train mass of 17 tons, developed a speed of 21 km / h. Later, the speed of the "Rocket" was increased to 45 km / h.
Railways began to play in the XVIII century. huge role. The first passenger railway in Russia with a length of 27 km, by decision of the tsarist government, was built by foreign entrepreneurs in 1837 between St. Petersburg and Pavlovsk. The Petersburg-Moscow double-track railway began operating in 1851.
In 1834, the father and son Cherepanovs built the first Russian steam locomotive (see Fig. 4.6, c, d), carrying a load of 3.5 tons at a speed of 15 km / h. Their subsequent locomotives carried cargo weighing 17 tons.
Attempts to use a steam engine in water transport have been made since the beginning of the 18th century. It is known, for example, that the French physicist D. Papin (1647–1714) built a boat driven by a steam engine. True, Papin did not achieve success in this matter.
Problem solved American inventor Robert Fulton (1765–1815), born in Little Briton (now Fulton), Pennsylvania. It is curious to note that the first great successes in the creation of steam engines for industry, railway and water transport fell to talented people who have acquired knowledge through self-education. Fulton was no exception in this regard. Fulton, who later became a mechanical engineer, came from a poor family, and at first did a lot of self-education. Fulton lived in England, where he was engaged in the construction of hydraulic structures and the solution of a number of other technical problems. While in France (in Paris), he built the Nautilus submarine and a steam ship which was tested on the Seine River. But all this was just the beginning.
Real success came to Fulton in 1807: returning to America, he built the Clermont paddle steamer with a carrying capacity of 15 tons, driven by a 20 hp steam engine. s., which in August 1807 made the first flight from New York to Albany with a length of about 280 km.
The further development of shipping, both river and sea, went quite quickly. This was facilitated by the transition from wooden to steel ship structures, the growth in power and speed of steam engines, the introduction of a propeller, and a number of other factors.
With the invention of the steam engine, man learned to convert energy concentrated in fuel into movement, into work.
The steam engine is one of the very few inventions in history that dramatically changed the picture of the world, revolutionized industry, transport, and gave impetus to a new rise in scientific knowledge. It was the universal engine of industry and transport throughout the 19th century, but its capabilities no longer met the requirements for engines that arose in connection with the construction of power plants and the use of high-speed mechanisms at the end of the 19th century.
Instead of a low-speed steam engine, a high-speed turbine with a higher efficiency enters the technical arena as a new heat engine.
Steam engines were used as a driving engine in pumping stations, locomotives, on steam ships, tractors, steam cars and other vehicles. Steam engines contributed to the widespread commercial use of machines in enterprises and were the energy basis of the industrial revolution of the 18th century. Later steam engines were superseded by internal combustion engines, steam turbines, and electric motors, which are more efficient.
invention and development
The first known device powered by steam was described by Hero of Alexandria in the first century. The steam coming out tangentially from the nozzles fixed on the ball made the latter rotate. The actual steam turbine was invented much later, in medieval Egypt, by the 16th-century Arab philosopher, astronomer, and engineer Taqi al-Din Muhammad ( English). He proposed a method of rotating the spit by means of a stream of steam directed to the blades fixed on the rim of the wheel. A similar machine was proposed in 1629 by the Italian engineer Giovanni Branca for rotating a cylindrical anchor device, which alternately raised and released a pair of pestles in mortars. 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.
However further development The steam engine demanded an economic environment in which engine developers could take advantage of their results. Such conditions did not exist either in antiquity, or in the Middle Ages, or in the Renaissance. It wasn't until the late 17th century that steam engines were created as singular curiosities. The first machine was created by the Spanish inventor Jeronimo Ayans de Beaumont, whose inventions influenced the T. Severi patent (see below). The principle of operation and application of steam engines was also described in 1655 by the Englishman Edward Somerset. In 1663 he published a design and installed a steam-powered device to raise water on the wall of the Great Tower at Raglan Castle (the recesses in the wall where the engine was installed were still visible in the 19th century). However, no one was willing to risk money for this revolutionary new concept, and the steam engine remained undeveloped. One of the experiments of the French physicist and inventor Denis Papin was the creation of a vacuum in a closed cylinder. In the mid-1670s in Paris, he collaborated with the Dutch physicist Huygens on a machine that forced air out of a cylinder by exploding gunpowder in it. Seeing the incompleteness of the vacuum created by this, Papin, after arriving in England in 1680, created a variant of the same cylinder, in which he obtained a more complete vacuum with the help of boiling water, which condensed in the cylinder. Thus, he was able to lift a load attached to the piston by a rope thrown over a pulley. The system worked like a demo, but to repeat the process, the entire apparatus had to be dismantled and reassembled. Papen quickly realized that in order to automate the cycle, the steam had to be produced separately in a boiler. Papin is therefore considered the inventor of the steam boiler, thus paving the way for the Newcomen steam engine. However, he did not propose the design of an operating steam engine. Papin also designed a boat, propelled by a jet-powered wheel, in a combination of the concepts of Taqi al-Din and Severi; he is also credited with inventing many important devices, such as a safety valve.
None of the described devices has actually been used as a means of solving useful problems. The first steam engine used in production was the "fire engine", designed by the English military engineer Thomas Savery in 1698. Severi received a patent for his device in 1698. It was a reciprocating steam pump, and obviously not very efficient, since the heat of the steam was lost each time the container was cooled, and rather dangerous in operation, because due to the high pressure of the steam, the tanks and engine pipelines sometimes exploded. Since this device could be used both to turn the wheels of a water mill and to pump water out of mines, the inventor called it a "miner's friend."
The first two-cylinder vacuum steam engine in Russia was designed by the mechanic I. I. Polzunov in 1763 and built in 1764 to drive blower bellows at the Barnaul Kolyvano-Voskresensky factories.
A further increase in efficiency was the use of high pressure steam (American Oliver Evans and Englishman Richard Trevithick). Trevithick successfully built industrial high-pressure single-stroke engines known as "Cornish engines". They operated at 50 psi, or 345 kPa (3.405 atmospheres). However, with increasing pressure, there was also a greater danger of explosions in machines and boilers, which initially led to numerous accidents. From this point of view, the most important element of the high-pressure machine was the safety valve, which 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 Nicolas-Joseph Cugnot demonstrated the first working self-propelled steam vehicle in 1769: 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 was already making regular service along the Delaware River between Philadelphia (Pennsylvania) and Burlington (state of New York). He lifted 30 passengers on board and went at a speed of 7-8 knots. On 21 February 1804, the first self-propelled railway steam locomotive, built by Richard Trevithick, was on display at the Penydarren ironworks at Merthyr Tydfil in South Wales.
Reciprocating steam engines
Reciprocating engines use steam power to move a piston in a sealed chamber or cylinder. The reciprocating action of a piston can be mechanically converted into linear motion for piston pumps, or into rotary motion to drive rotating parts of machine tools or vehicle wheels.
vacuum machines
Engraving of a Newcomen engine. This image is copied from a drawing in Desaglieres' A Course in Experimental Philosophy, 1744, which is a modified copy of an engraving by Henry Beaton dated 1717. Probably depicted is the second [hoy]Newcomen engine installed around 1714 in the Greef colliery in Workshire.
Early steam engines were called at first "fire engines", and also "atmospheric" or "condensing" Watt engines. They worked on the vacuum principle and are therefore also known as "vacuum engines". Such machines worked to drive piston pumps, in any case, there is no evidence that they were used for other purposes. During the operation of a vacuum-type steam engine, at the beginning of the cycle, low-pressure steam is admitted into the working chamber or cylinder. Inlet valve after that, it closes, and the steam cools, condensing. In a Newcomen engine, the cooling water is sprayed directly into the cylinder and the condensate escapes into a condensate collector. This creates a vacuum in the cylinder. Atmospheric pressure at the top of the cylinder presses on the piston, and causes it to move down, that is, the power stroke.
Constant cooling and reheating of the working cylinder of the machine was very wasteful and inefficient, however, these steam engines allowed pumping water from a greater depth than was possible before their appearance. In 1774, 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 closed by a valve. A special small vacuum pump (a prototype of a condensate pump) was attached 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 the feed pump) back to the boiler. Another radical change was the closure upper end working cylinder, in the upper part of which 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 steam was transferred through special tubes to the lower part of the cylinder in order to be condensed during the next stroke. The machine, in fact, ceased to be "atmospheric", and its power now depended on the pressure difference between low-pressure steam and the vacuum that could be obtained.
Watt's version of the steam engine
In the Newcomen steam engine, the piston was lubricated with a small amount of water poured on top of it, in Watt's engine this became impossible, since steam was now 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 stuffing box.
Vacuum steam engines, despite the obvious limitations of their efficiency, were relatively safe, using low pressure steam, which was quite consistent with the general low level of 18th century boiler technology. The power of the machine was limited by low steam pressure, cylinder size, the rate of fuel combustion and water evaporation in the boiler, and the size of the condenser. The maximum theoretical efficiency was limited by the relatively small temperature difference on either side of the piston; it did vacuum machines, intended for industrial use, are too large and expensive.
Steam distribution
Indicator diagram showing the four-phase cycle of a double-acting reciprocating steam engine
In most reciprocating steam engines, steam changes direction with each stroke of the operating cycle, entering and exiting the cylinder through the same manifold. A complete engine cycle takes one full revolution of the crank and consists of four phases - intake, expansion (working phase), exhaust and compression. These phases are controlled by valves in a "steam box" adjacent to the cylinder. Valves control the flow of steam by connecting the manifolds on each side of the working cylinder in series to the intake and exhaust manifolds of the steam engine. The valves are driven by some type of valve mechanism. The simplest valve mechanism gives a fixed duration of the working phases and usually does not have the ability to change the direction of rotation of the machine shaft. Most valve mechanisms are more advanced, have a reverse mechanism, and also allow you to adjust the power and torque of the machine by changing the "steam cutoff", that is, changing the ratio of the intake and expansion phases. Since usually the same sliding valve controls both the inlet and outlet steam, changing these phases also symmetrically affects the relationship between the exhaust and compression phases. And here there is a problem, since the ratio of these phases should ideally not change: if the exhaust phase becomes too short, then most of the exhaust steam will not have time to leave the cylinder, and will create a significant back pressure in the compression phase. In the 1840s and 1850s, many attempts were made to get around this limitation, mainly by creating circuits with an additional shut-off valve mounted on the main control valve, but such mechanisms did not work satisfactorily, and were also too expensive and complicated. Since then, the usual compromise solution has been to lengthen the sliding surfaces. spool valves so that the inlet window is closed longer than the outlet. Later schemes with separate intake and exhaust valves were developed that could provide an almost perfect cycle of operation, but these schemes were rarely used in practice, especially in transport, due to their complexity and operational problems.
Compression
The outlet port of a steam engine cylinder closes slightly before the piston reaches its end position, leaving some exhaust steam in the cylinder. This means that there is a compression phase in the work cycle, which forms the so-called "vapor cushion", slowing down the movement of the piston in its extreme positions. Moreover, it eliminates sharp drop pressure at the very beginning of the intake phase, when fresh steam enters the cylinder.
Advance
The described “vapor cushion” effect is also enhanced by the fact that the intake of fresh steam into the cylinder begins somewhat earlier than the piston reaches its extreme position, that is, there is some advance of the intake. 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 not used for piston movement.
simple extension
A 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. The residual heat of the steam can then be used, for example, to heat a room or a vehicle, as well as to preheat the water entering the boiler.
Compound
During the expansion process in the cylinder of a high-pressure machine, the temperature of the steam drops in proportion to its expansion. Since there is no heat exchange (adiabatic process), it turns out that the steam enters the cylinder at a higher temperature than it leaves it. 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 Wulff high-pressure compound steam engine. In this machine, high-temperature steam from the steam boiler entered the 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 generally reduced temperature losses and improved the overall efficiency of the steam engine. The low-pressure steam had a larger volume, and therefore required a larger volume of the cylinder. Therefore, in compound machines, the low pressure cylinders had a larger diameter (and sometimes longer) than the high pressure cylinders.
This arrangement is also known as "double expansion" because the vapor expansion occurs in two stages. Sometimes one high-pressure cylinder was connected to two low-pressure cylinders, resulting in three approximately the same size cylinders. Such a scheme was easier to balance.
Two-cylinder compounding machines can be classified as:
- Cross compound- Cylinders are located side by side, their steam-conducting channels are crossed.
- Tandem compound- Cylinders are arranged in series and use one rod.
- Angle compound- The cylinders are at an angle to each other, usually 90 degrees, and operate on one crank.
After the 1880s, compound steam engines became widespread in manufacturing and transportation, and became virtually the only type used on steamboats. Their use on steam locomotives was not as widespread as they proved to be too complex, partly due to the difficult operating conditions of steam engines in rail transport. Although compound locomotives never became a mainstream 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 expansion
The logical development of the compound scheme was the addition of additional expansion stages to it, which increased the efficiency of 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 that increased in volume with each stage. Sometimes, instead of increasing the volume of low pressure cylinders, an increase in their number was used, just as on some compound machines.
The image on the right shows a triple expansion steam engine in operation. Steam flows through the machine from left to right. The valve block of each cylinder is located to the left of the corresponding cylinder.
The appearance of this type of steam engines became especially relevant for the fleet, since the size and weight requirements for ship engines were not very strict, and most importantly, this scheme made it easy to use a condenser that returns the exhaust steam in the form of fresh water back to the boiler (use salty sea water to power the boilers was not possible). Ground-based steam engines usually did not experience problems with water supply and therefore could emit exhaust steam into the atmosphere. Therefore, such a scheme was less relevant for them, especially considering its complexity, size and weight. The dominance of multiple expansion steam engines ended only with the advent and widespread use of steam turbines. However, modern steam turbines use the same principle of dividing the flow into sections of high, medium and low pressure.
Direct-flow steam engines
Once-through steam engines arose as a result of an attempt to overcome one drawback inherent in steam engines with traditional steam distribution. The fact is that the steam in an ordinary 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 its walls and steam distribution channels. Fresh steam, accordingly, spends a certain part of the energy on heating them, which leads to a drop in efficiency. Once-through 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 improves 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. Once-through single expansion machines show about the same efficiency as compound machines with conventional steam distribution. In addition, they can work for more high revs, and therefore, before the advent of steam turbines, they were often used to drive electric generators that required high rotational speeds.
Once-through steam engines are either single or double acting.
Steam turbines
A steam turbine is a drum or a series of rotating disks fixed on a single axis, they are called a turbine rotor, and a series of fixed disks alternating with them, fixed on a base, called a stator. The rotor disks have blades on the outer side, steam is supplied to these blades and turns the disks. The stator disks have similar (in active or similar in reactive) blades installed at an opposite angle, which serve to redirect the steam flow to the following rotor disks. Each rotor disc and its corresponding stator disc is called a turbine stage. The number and size of the stages of each turbine are selected in such a way as to maximize the use of the useful energy of the steam of the speed and pressure that is supplied to it. The exhaust steam leaving the turbine enters the condenser. Turbines spin at very high speeds, and so special step-down transmissions are commonly used when transferring power to other equipment. In addition, turbines cannot change their direction of rotation, and often require additional reverse mechanisms (sometimes additional reverse rotation stages 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 have more simple design they tend to require less maintenance.
Other types of steam engines
In addition to reciprocating steam engines, rotary steam engines were actively used in the 19th century. In Russia, in the second half of the 19th century they were called " rotary machines" (that is, "rotating the wheel" from the word "kolo" - "wheel"). There were several types, but the most successful and effective was the "rotary machine" of the St. Petersburg mechanical engineer N. N. Tverskoy. Steam engine of N. N. Tverskoy. The machine was a cylindrical body in which the impeller rotor rotated, and special locking drums locked the expansion chambers. The “rotary machine” of N. N. Tverskoy did not have a single part that would perform reciprocating movements and was perfectly balanced. The Tversky engine was created and operated mainly on the enthusiasm of its author, but it was used in many copies on small ships, in factories and to drive dynamos. One of the engines was even installed on the Shtandart imperial yacht, and as an expansion machine - driven by a cylinder of compressed ammonia gas, this engine set in motion one of the first experimental submarines - the "underwater destroyer", which was tested by N N. Tversky in the 80s of the 19th century in the waters of the Gulf of Finland. However, over time, when steam engines were replaced by internal combustion engines and electric motors, N. N. Tverskoy's "rotary machine" was practically forgotten. However, these "rotary machines" can be considered the prototypes of today's rotary internal combustion engines.
Application
Steam engines can be classified according to their application as follows:
Stationary machines
steam hammer
Steam engine in an old sugar factory, Cuba
Stationary steam engines can be divided into two types according to the mode of use:
- Variable duty machines such as rolling mills, steam winches and similar devices that must stop and change direction frequently.
- Power machines that rarely stop and do not have to change direction of rotation. They include power motors in power stations, as well as industrial motors used in factories, factories, and cable railways before the widespread use of electric traction. Low power engines are used in marine models and in special devices.
The steam winch is essentially a stationary engine, but mounted on a base frame so that it can be moved around. It can be secured by a cable to the anchor and moved by its own thrust to a new location.
Transport vehicles
Steam engines were used to power various types of vehicles, among them:
- Land vehicles:
- 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 Nizhny Tagil plant in 1834 to transport ore. He developed a speed of 13 miles per hour and carried more than 200 pounds (3.2 tons) of cargo. The length of the first railway was 850 m.
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 internal combustion engines, 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 sources of heat 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 also have similar properties, such as the Stirling engine, which can provide very high efficiency, but have significantly greater weight and dimensions than modern types of steam engines.
Steam locomotives perform well at high altitudes, since their efficiency does not drop due to low atmospheric pressure. Steam locomotives are still used in the mountainous regions of Latin America, despite the fact that in the flat areas they have long been replaced by more modern types locomotives.
In Switzerland (Brienz Rothhorn) and Austria (Schafberg Bahn), new steam locomotives using dry steam have proved their worth. This type of steam locomotive was developed from the Swiss Locomotive and Machine Works (SLM)'s models, with many modern improvements such as the use of roller bearings, modern thermal insulation, burning light oil fractions as fuel, improved steam pipelines, etc. As a result, such locomotives have 60% less fuel consumption and significantly lower maintenance requirements. The economic qualities of such locomotives are comparable to modern diesel and electric locomotives.
In addition, steam locomotives are significantly lighter than diesel and electric locomotives, which is especially true for mountain railways. A feature of steam engines is that they do not need a transmission, transferring power directly to the wheels. At the same time, the steam engine of a steam locomotive continues to develop pulling force even in the case of a stop of the wheels (emphasis on the wall), which is different from all other types of engines used in transport.
Efficiency
A steam engine venting steam to the atmosphere will have a practical efficiency (boiler included) of 1 to 8%, but an engine with a condenser and expansion of the flow path can improve efficiency by up to 25% or even more. A thermal power plant with a superheater and regenerative water heating can achieve an efficiency of 30 - 42%. Combined cycle plants, in which fuel energy is first used to drive a gas turbine and then to a steam turbine, can reach an efficiency of 50 - 60%. At CHP plants, efficiency is increased by using partially exhausted steam for heating and production needs. In this case, up to 90% of the energy of the fuel is used and only 10% is dissipated uselessly in the atmosphere.
Such differences in efficiency are due to the peculiarities of the thermodynamic cycle of steam engines. For example, the largest heating load falls on winter period, so the CHP efficiency increases in winter.
One of the reasons for the decrease in efficiency is that the average temperature of the steam in the condenser is slightly higher than the temperature environment(formed so-called.
The steam engine became the first mechanical engine for which there was a wide practical application. The first reciprocating steam engines were first used in factory production, and later they were able to be connected to wheels and get self-propelled machines:
- steamships;
- locomotives;
- tractors;
- cars.
History of the invention of the steam engine
The basic principle of operation of any steam engine is that the energy of hot steam is converted into mechanical energy, which can be:
- reciprocating;
- rotational.
And the resulting mechanical energy can already be used for useful purposes. The principle of operation of a steam engine was clear to the ancient Greeks, but in the dark ages people forgot about it. Again, interest in this problem revived only in the 17th century. The Italian Giovanni Branca proposed a model of his own steam turbine in 1629. But due to unacceptably large energy losses, this first steam engine in the world did not find practical application.
This Frenchman, a physician by education, moved to England in 1675, where he was noted for a number of inventions. So, he invented the "Papenov's boiler" - the prototype of a modern double boiler. Papen was able to notice the relationship between the increase in pressure and the boiling point of a liquid. He was able to build an airtight boiler, where increased pressure was maintained. As a result, the water in it boiled at elevated temperature, and it became possible to cook food at temperatures above 100 degrees, which speeded up the cooking process.
On the eve of moving to Foggy Albion, Papin invented a powder engine. Gunpowder burning in the cylinder pushed the piston. The resulting powder gases were removed through the valve, and the remaining ones cooled, due to which a slight rarefaction occurred in the cylinder, and the pressure of the atmosphere returned the piston to its place.
By the same principle, Papin created in 1698 a similar engine, but already on the water. It was actually the first steam engine.
Despite the fact that the idea itself promised considerable benefits, it did not bring dividends to its author. The fact is that a little earlier, Savery (an English mechanic) patented his steam pump, which at that time was the only way to use a steam engine. It so happened that the inventor of the first steam engine, Denis Papin, died in 1714 in London, being poor and lonely.
Thomas Newcomen's car
This enterprising Englishman was able to achieve big profits. He was 35 years old when the Papin machine was created. Newcomen carefully studied the legacy of Papin and Savery and noted the shortcomings of both models, and adopted strong ideas. Collaborating with a specialist in plumbing and glass D. Calli, Newcomen created his first model by 1712, continuing the history of the creation of steam engines. Her basic work looked like this:
- the design had a vertical cylinder with a piston (from Papin);
- steam was generated in a separate boiler, which operated on the principle of Savery's invention;
- The tightness of the steam cylinder was ensured by skin tight around the piston.
By building up pressure, Newcomen's device raised water from the mines. But it was very bulky and extremely voracious on coal. But these shortcomings did not prevent half a century of operation of this invention in the mines. Thanks to him, it became possible to revive mines that were previously abandoned due to groundwater flooding. But since his machine was a compilation of early inventions, Newcomen could not get a patent for it.
Watt machine
The decisive step was taken by the Briton James Watt, thanks to whose efforts a sufficiently powerful and compact first reciprocating steam engine appeared. As a mechanic at the University of Glasgow, in 1763 Watt took up the repair of Newcomen's steam engine. During the repair process, he came up with a way to reduce her gluttony - her cylinder had to be kept warm.
But it was necessary to solve the problem of steam condensation. He caught the solution as he passed laundries, steam pouring from the lids of their boilers. He realized that steam is a gas, which should be put into a cylinder with reduced pressure. He achieved a tight piston-cylinder system by wrapping the first with oiled hemp rope, after which it became possible to abandon atmospheric pressure - a noticeable step forward.
In 1769, Watt patented a steam engine in which the temperature of the steam and important details was the same.
Video of James Watt's first steam engine
But in life, Watt was less lucky, and he had to pawn the patent for debts. After 3 years, he met a wealthy industrialist Matthew Bolton, who bought Watt his patents. Under his tutelage, Watt returned to work. Already in 1773 new model Watta demonstrated much lower coal consumption in tests than her predecessors required. And a year later, England began the industrial production of Watt machines. In 1781, Watt patented a steam engine that powered industrial machines. A little later, these same technologies began to be used for the movement of ships and trains, which will become a true technical revolution.
No less dear to us is Ivan Polzunov, the Russian inventor of the first steam engine, which was able to power many working mechanisms. Moreover, he made this invention before White - in 1763, while working at the Altai mining plants. He acquainted the head of the factories with his project, and he received approval from the capital to assemble the unit. Polzunov was ordered to build a large machine.
This work took 21 months, but when it was almost ready, the consumptive inventor died a few days before her first tests. Polzunov's steam engine could work continuously and in automatic mode. This was proven as a result of tests conducted in 1766 by Polzunov's students. A month later, the machine had already begun to work, not only recouping all the costs of its creation, but also bringing profit to the owners.
Who do you think was the first inventor of the steam engine? Tell about it in
People were able to put steam at the service of mankind only at the very end of the 17th century. But even at the beginning of our era, the ancient Greek mathematician and mechanic Heron of Alexandria clearly showed that it is possible and necessary to be friends with the steam. A clear confirmation of this was the Geronian eolipil, in fact, the first steam turbine - a ball that rotated with the power of jets of water vapor. Unfortunately, many amazing inventions of the ancient Greeks were forgotten for many centuries. It is only in the 17th century that a description of something resembling a steam engine refers. The Frenchman Salomon de Caus, who at one time was a builder and engineer with Frederick V of the Palatinate, in his work of 1615 described a hollow iron ball with two tubes: receiving and removing liquid. If you fill the ball with water and heat it, then the water will begin to rise up through the second tube, obeying the influence of vapors. In 1663, the Englishman Edward Somerset, Marquis of Worcester, wrote a pamphlet in which he spoke about a machine that could lift water up. Then Somerset received a patent ("privilege") for the described machine. As you can see, all the thoughts of the inventors of the New Age revolved around pumping water out of mines and mines, which, it should be noted, stemmed from an urgent task. Therefore, it is not surprising that the next three inventors, which will be discussed below, were also primarily concerned with the creation of a steam engine for pumping water. Toward the very end of the 17th century, two men in Europe worked more effectively than others to tame steam - Denis Papin (Denis Papin) and Thomas Savery (Thomas Savery).
"Fire" machine Savery.
On July 2, 1698, the Englishman Savery received a patent for a machine for pumping water from mines. The patent stated: "The privilege is complained to Thomas Savery for his alone testing a new invention for lifting water, turning all kinds of mills by the forces of fire, which will be very important for draining mines, supplying cities with water and turning all kinds of mills." A prototype called the "Fire engine" (Fire engine) in 1699 was paraded at the Royal Society in London. Savery's machine worked in this way: a sealed tank was filled with steam, and then the outer surface of the tank was cooled with cold water, due to which the steam condensed, creating a partial vacuum in the tank. Then the water from the bottom from the bottom of the mine through the intake pipe was sucked into the tank and, after the admission of a new portion of steam, was pushed out through the outlet pipe. It is worth noting that Savery's invention was similar to Somerset's machine, and many believe that Savery was directly based on the latter. Unfortunately, Savery's "fiery" machine had some shortcomings. The most important of them is the inability to raise water from a depth of more than 15 meters, although at that time there were already mines whose depth exceeded 100 meters. In addition, the machine consumed a lot of fuel, which was not justified even by the proximity of a large amount of coal in the mine. The Frenchman Denis Papin, a physician by training, moved to London in 1675. Papen made several discoveries that forever inscribed his name in history. To begin with, Papin invents a pressure cooker - "Papen's cauldron". The former physician was able to establish the relationship between pressure and the boiling point of water. Sealed boiler with safety valve thanks to high blood pressure inside, he brought the water to a boil much later, so the temperature of the food processing increased and the latter were cooked many times faster. In 1674, Papin created a powder engine: gunpowder was ignited in a cylinder, which caused the piston to move inside the cylinder. One "batch" of gases was released from the cylinder through a special valve, and the other was cooled. A vacuum (albeit a weak one) was formed in the cylinder, and atmospheric pressure lowered the piston down. In 1698, Papin invented a steam engine using water that was heated inside a vertical cylinder - the resulting steam moved the piston up. The cylinder was then cooled with water, the steam condensed and a vacuum was created. All the same atmospheric pressure forced the piston to lower. Despite the progressiveness of his machine (the presence of a piston), Papin could not extract any significant dividends from it, since Savery patented a steam pump, and there were no other applications for steam engines at that time (although Savery's patent indicated the possibility of "rotation mills"). In 1714, in the capital of the British Empire, Papin died in need and loneliness. Far more fortunate was another Englishman, Thomas Newcomen, born in 1663. Newcomen carefully read the work of both Savery and Papin, weak spots previous machines, while taking the best from them. In 1712, together with glazier and plumber John Calley, he built his first steam engine. It used a vertical cylinder with a piston, like the Papin machine. However, the steam was generated in a separate steam boiler, which was similar to the principle of operation of Savery's "fiery" machine. The tightness inside the steam cylinder was enhanced by the skin being secured around the piston. Newcomen's machine was also vapor-atmospheric, i.e. the rise of water from the mine was carried out under the influence of atmospheric pressure. She was rather bulky and "ate" a lot of coal. Nevertheless, Newcomen's machine brought incomparably more practical use, which is why it was used in mines for almost half a century. In England, for example, it allowed the reopening of abandoned mines that were flooded with groundwater. And another striking example of the effectiveness of Newcomen's machine - in 1722 in Kronstadt, in a dry dock, water was pumped out of the ship from the ship within two weeks, while with an outdated pumping system using windmills, it would have taken a year. Despite all this, Thomas Newcomen did not receive a patent for his steam engine because of Savery's patent. The possibility of using a Newcomen steam engine to propel a vehicle was considered by the designers, in particular, to drive a paddle wheel on a ship. However, the attempts were not crowned with success. The compact but powerful steam engine was invented by James Watt. In 1763 Watt, a mechanic at the University of Glasgow, was given the task of fixing Newcomen's steam engine. In the process of repair, Watt comes up with the following idea - the cylinder of the steam engine must be kept constantly heated, which will drastically reduce fuel consumption. It only remained to figure out how to condense the steam in this case. It dawned on Watt when he made an evening exercise near the laundries. At the sight of clouds of steam trying to get out from under the covers of the boilers, the inventor suddenly realized that the steam is a gas, and it must move into a cylinder with reduced pressure. Watt resolutely gets down to business. He uses a water pump and metal tubes, from which the pump will pump out water and steam, creating a reduced pressure in the latter, and it, from the tubes, will begin to be transferred to the working cylinder of the steam engine. For the power stroke, Watt uses steam pressure, thereby giving up atmospheric pressure, which was a big step forward. For this purpose, so that steam does not pass between the cylinder and the piston, a hemp rope soaked in oil was wrapped around the piston along special grooves. This method made it possible to achieve a sufficiently high tightness inside the steam cylinder. In 1769, Watt received a patent for "a steam engine in which the temperature of the engine will always be equal to the temperature of the steam, despite the fact that the steam will be cooled to a temperature below one hundred degrees." In 1772, James Watt met the industrialist Matthew Bolton. This wealthy gentleman bought and returned to Watt all his patents, which the unlucky inventor had to pawn for debts. With Bolton's encouragement, Watt's work accelerated. Already in 1773, Watt was testing his steam engine; it performed the same function as a steam pump, but required much less coal. Seeing the obvious advantages of Watt's machine, Bolton opens a company with the inventor to produce steam engines, and in 1774 their production begins in England. The implementation of steam engines was going so well that Bolton wanted to build a new rolling mill, for which he asked Watt to create a special steam engine to drive rolling machines. Watt brilliantly coped with the task, and in 1781 he patented a steam engine "for the implementation of movement around an axis for the purpose of driving other machines." Thus, the first steam engine was born not to raise water from the bottom of mines, but to set machines in motion. Watt's new machine had a number of improvements. For example, a regulator for uniform rotation of the main shaft of a steam engine, as well as a planetary mechanism for creating roundabout. The last Watt invents because to apply crank mechanism he is not allowed by the current patent. But in 1784, Watt still managed to get permission to use a crank mechanism in a steam engine. Thus, the world's first universal steam engine, created by Watt, began to set in motion industrial machines, heralding the advent of the era of steam engines. Very soon, steam will move steamboats and trains, due to which human life will change radically. The enormous merits of James Watt did not go unnoticed by posterity - in 1819, by order of the English Parliament, a marble monument was erected to the great inventor in Westminster Abbey. It is believed that the first steamboat was built by the American Robert Fulton in 1807 - his paddle-wheel ship was called the Claremont. At first, Fulton tried to use steam to drive the oars, but then he turned to the more successful idea of \u200b\u200bthe wheel. Fulton made his first voyage on the Claremont alone, as the inhabitants of the surrounding area flatly refused to sit in the "devilish" smoky vessel. But on the way back to Fulton, one brave man nevertheless got hooked, for which he received from the inventor the right to a lifetime free ride on the Claremont. Then the flights of the Fulton ship became commonplace - the Claremont transported people along the Hudson River from New York to Albany, developing at a speed of about 5 knots (9 km / h). The first screw steamer was built in 1838 by Englishman Francis Smith. The use of propellers instead of paddle wheels has significantly improved driving performance steamships. Auxiliary sails are gradually disappearing on steamboats (remember that in 1819 the American steamer Savannah crossed the Atlantic Ocean for the most part with the help of sails), and by the beginning of the 20th century, the sailing ships themselves go down in history. The first steam locomotive was built by Briton Richard Trevithick. It was a steam-powered wagon moving along rails at a speed of 7 km/h and carrying a train weighing 7 tons. In 1804, a small railroad was built in London to test the Trevithick steam locomotive. In our time, both steamboats and steam locomotives have long become a historical curiosity, which, however, can be found in the most different countries. So, in Norway, on Lake Mjøs, the oldest paddle steamer in the world, the Skibladner, built back in 1856, still operates. In turn, steam locomotives are actively operated in third world countries, which means that steam still serves humanity faithfully."Steam Cart" Cugno.
A separate milestone in the history of steam - steam cars. The first operating steam car ("steam cart") was built by the Frenchman Nicolas-Joseph Cugnot (Cugot) in 1769. It was a very heavy cart, weighing more than a ton, which two people could barely handle. Aesthetically, the car did not look very nice - the boiler, like a pot on a grip, was placed in front of the transport. "Cart" Cugno developed a speed of about 2-4 km / h and could carry up to 3 tons of cargo. It was difficult to operate it - to maintain the steam pressure, which was rapidly falling, it was necessary to stop every quarter of an hour and light the firebox. In the end, on another test drive, Cugnot and the stoker (by the way, the stoker in French sounds like "chauffeur", from which the word "chauffeur" then came from) crashed on a sharp turn, which caused the boiler to explode, making noise all over Paris. Cugno built a new "cart", but it did not go to the masses. In 1794 it was handed over to the museum. Another Frenchman, Leon Emmanuel Serpollet, made a significant contribution to the development of steam vehicles. In 1875, he created a small but powerful steam car. Leon decided that it would be better to heat the water not in a boiler, but in heated tubes, where it turns into steam very quickly. Serpollet's first working machine was a two-seat, three-wheeled wooden carriage. At first, the police forbade the Frenchman to travel even at night, but in 1888 they still gave in and issued an official travel permit paper. Serpolla didn't stop there. Instead of coal, he begins to use liquid fuel, which was fed to two burners. In 1900, he opens a company together with the American Frank Gardner (Frank Gardner) - Gardner-Serpollet. In 1902, Serpollet created a racing steam car and set a world speed record on land with it in Nice - 120.77 km / h. It is not surprising that at that time steam cars competed quite successfully with gasoline and electric counterparts. The first ones flourished especially in the USA, where, for example, in 1900, 1690 steam, 1585 electric and only 936 gasoline cars were produced. Steam cars were used in the USA until the 1930s. In the first half of the 19th century, steam tractors were also built, in particular, with caterpillar tracks. However, the efficiency of steam engines was only 5%. For this reason, at the beginning of the 20th century, steam engines in cars were replaced by internal combustion engines. With their help, cars have become more economical, lighter and faster. It is impossible not to mention other, less successful applications of steam in the late 19th and early 20th centuries. The widespread use of steamboats, steam locomotives and steam cars prompted inventors to think that steam could be used in aviation and in the army. Alas, steam could not be useful in these areas. Although by the middle of the nineteenth century there were several attempts to create airplanes with a steam engine. The Englishman William Henson built the Ariel Steam Carridge apparatus, which had a 25-30 hp steam engine that drove propellers with a diameter of 3.05 m. To reduce the weight of the machine, the conventional boiler was replaced by a system of vessels conical shape using an air condenser. In 1844-1847, Henson unsuccessfully tested his airplanes. They all ended in failure. But already in 1848, John Stringfellow nevertheless built an airplane that took off the ground, although not for long. The apotheosis of "feromania" in the aircraft industry was the Hayrem Stevens Maxim airplane, which had a 360 hp steam engine, and could be compared with a two-story house in size. It is not surprising that Maxim's airplane crashed overnight, like all man's dreams of conquering the air with the help of steam. Although, we note that in 1896, the American Samuel Pierpont Langley (Samuel Pierpont Langley) nevertheless built an airplane with a steam engine, which flew about a kilometer without a pilot until it ran out of fuel. Langley called his creation "airfield" (translated from ancient Greek - "running in the air"). However, by the beginning of the 20th century, it was clear to everyone that bulky steam engines were not suitable for aeronautics, especially since by that time gasoline engines had proven themselves to be excellent on airplanes - on December 17, 1903, the famous Wright brothers airplane appeared in the sky, equipped with a gasoline engine. Things were no better with the steam in the army. But even Leonardo da Vinci himself described a cannon that fires projectiles with the power of only fire and water. The great Florentine suggested that a long copper barrel with a core, placed in the furnace at one end, could throw a projectile if a little water was injected into the compartment behind the core when the pipe was very hot. Leonardo believed that water at such a high temperature would evaporate very quickly and, becoming an analogue of gunpowder, would push the core out at great speed. It is worth noting that the idea of the steam gun is attributed to Archimedes. The ancient manuscripts mention that during the siege of Syracuse in 212 BC, Roman ships were fired from cannons. But then there was no gunpowder in Europe! And Leonardo da Vinci suggested that Archimedes, whose devices defended Syracuse, had steam cannons. The Greek engineer Ionis Sakkas decided to test this idea of da Vinci. He built a wooden cannon, to the back of which a cauldron heated to 400°C was attached. As suggested by Leonardo da Vinci, water was supplied to a special valve, which, evaporating instantly, burst into the muzzle with steam, which caused the concrete core in Sakkas's experiments to fly away at a distance of 30-40 m. Students of the University of MIT and participants in the television series "MythBusters", however, without success, similar to the achievement of Saccas. In the 19th century, they returned to the steam again, but it was not possible to create a really combat-ready weapon (cannon or machine gun). In 1826-1829, the Russian engineer-colonel of the communications corps A. Karelin made a copper 7-linear (17.5 mm) experimental steam gun. Shooting was carried out with ball bullets using water vapor, the rate of fire reached 50 rounds per minute. But tests conducted in 1829 did not impress the "selection committee", which considered the gun too complicated for use in the field. At the end of this article, one cannot fail to mention steampunk (English "steampunk", from "steam" - "steam" and "punk" - "protest"). This branch of science fiction describes the steam era of Victorian England (second half of the 19th century) and early capitalism (early 20th century). City landscapes, characters, public moods, etc. are described accordingly. The term itself appeared in 1987. The steampunk genre gained popularity after the appearance of the novel " difference engine"William Gibson and Bruce Sterling (1990). The forerunners of steampunk can be called Jules Verne and Grigory Adamov. In last years many steampunk movies have appeared, the most famous of them are Wild Wild West (1999), The Time Machine (2002), The League of Extraordinary Gentlemen (2003) and Van Helsing (2004). Steampunk is chronologically adjacent to dieselpunk - a genre that describes the technological world of the 20-50s of the XX century, which, it should be noted, is very close to the technoworld of the early XX century.The invention of the steam engine was a turning point in the industrial and general history of mankind. At the turn of the 17th-18th centuries, prerequisites appeared for replacing low-power and inefficient living "engines", windmills and water wheels with mechanisms of a completely new type - steam engines. It was steam engines that made possible the industrial revolution and the achievement of the modern level of technological development.
It is believed that invented the first steam engine Scottish mechanic James Watt - after all, it is not for nothing that the international unit of power Watt is named after him! However, in reality, Watt made a lot of improvements and proposed a new type of engine, and the history of steam engines dates back much earlier.
The use of steam to actuate a mechanism was first described by the ancient Greek scientist Heron of Alexandria, who worked around the 1st century AD. e. It was Heron who invented the famous Eolipil (or "Eol's ball") - a sphere fixed on an axis with nozzles coming out of it. A ball filled with water was heated on fire, and the steam coming out of the nozzles caused the sphere to rotate.
Of course, all this is nothing more than a toy, but it has been forgotten for more than a millennium and a half. For the first time after Heron, the Arab engineer and philosopher Tagi al-Dinome tried to use the power of steam - in the 16th century he created a prototype of a steam turbine that rotated a spit. Almost a century later - in 1615 - the Frenchman Solomon de Caux describes a device that, with the help of steam, can raise water. And in 1629, the Italian Giovanni Branca also creates turbine-like machine, - heated steam came out of the tube and hit the blades on the wheel, thereby causing this wheel to rotate.
Around the same time, the Spanish engineer Jeronimo Ayanz de Beaumont created steam engine with cylinder- this mechanism had some influence on the development of events in the field of improving steam engines. And in 1663, the Englishman Edward Somerset describes a steam engine for lifting water from wells and mines, and subsequently receives a patent for this invention. The machine created by Somerset worked for some time in one of the English castles, but showed far from the best results.
Two people played a huge role in the development of steam engines: the Frenchman Denis Papin and the Englishman Thomas Savery. Pa-pen invented a cylinder in the mid-70s of the 17th century, in which a vacuum is created by the explosion of gunpowder, and then (in 1680) he adapted this cylinder to work from steam. By the end of the century, a French scientist approached the creation of an industrial model of a steam engine, but Savery was ahead of him - in 1698 an Englishman received a patent for a machine, and in 1702 the mechanism of its design began to be used to lift and pump out water. However, these steam engines received a very limited distribution - they were too imperfect.
But if the devices of Papin and Savery were little used in practice, then why did these people play important role in the history of technology? The thing is that the ideas of these engineers-inventors formed the basis of the steam engine, created in 1712 by the Englishman Thomas Newcomen. The inventor combined a Savery-designed machine with a Papin cylinder, resulting in a fairly perfect steam-powered engine. An interesting detail: the machine was controlled manually - for this purpose a special person was hired, whose task was to open and close the valves at certain intervals. According to legend, in 1713, a boy named Humphrey Potter, who worked on one of the machines, figured out how to make the valves work on their own. And only in 1715 on the steam engines of the Newcomen system appeared completely automatic system steam distribution.
Two important remarks must be made here. First, all of the above steam engines are vacuum(or atmospheric). In machines of this type, steam was used only to heat the cylinder in which the piston moved. The principle is simple: steam enters the cylinder, heating it to a high temperature, after which cold water is poured onto the cylinder. As a result, a sharp cooling occurs, and a rarefaction (vacuum) is formed in the cylinder, due to which, under the influence of atmospheric pressure, the piston enters deep into the cylinder, while doing work. Secondly, all these machines were used only for lifting and moving water - it never occurred to the inventors that various mechanisms could be set in motion with the help of steam. So even Newcomen's car often referred to as a steam pump.
For more than half a century, Newcomen's steam engines were the only machines suitable for industrial use. It was only in the early 1760s that progress occurred in this area - Humphrey Gainsborough created improved steam engine, which, however, has not received significant distribution. And the Scottish engineer and inventor James Watt was destined to make a real revolution in this area.
In 1765, Watt put forward the idea that it is not necessary to cool the cylinder, but it is better to use the force of steam pressure, and not vacuum. Already in 1769, he received a patent for this invention, but the new design machine itself was created only in 1776 - Watt at that time was tight with money and he simply had nothing to implement his ideas.
But the most important invention of James Watt, which made him famous, appeared only in 1781: it was then that the engineer created a steam engine capable of doing any job. This was made possible by converting the reciprocating motion of the piston into the rotation of the flywheel using the so-called planetary mechanism. And in 1784, Watt's steam engine acquired its final form - a more convenient and simple crank mechanism and many minor improvements appeared in it. It was this development that became known as universal steam engine, and not in vain: the machine soon appeared in factories and factories, and at the beginning of the 19th century, the Watt system engines were installed on the first steam locomotive and steamboat.
It is interesting that a functioning steam engine (and not even one) was also created in Russia - that's all famous cars Ivan Polzunov, built between 1763 and 1766. Polzunov's first engines showed good results, and in 1764 construction began on a large steam engine for a metal foundry. Construction ended in 1766, and the launch was made after the death of the inventor. Unfortunately, Polzunov's steam engine worked for only 42 days - after a breakdown, it ceased to be used, and after some time it was dismantled.
As you can see, the history of steam engines does not begin with the discovery of James Watt, but it was this inventor who created a truly efficient and comfortable car which had a huge impact on the development of industry and technology. For these merits, in 1882, the unit of power, known to us as the watt, began to be named after Watt.
