What any steam engine consists of. The history of the invention of steam engines. Creation of a steam engine. Steampunk as a trend in the era of steam engines

It began its expansion at the beginning of the 19th century. And already at that time, not only large units for industrial purposes were being built, but also decorative ones. Most of their buyers were wealthy nobles who wanted to amuse themselves and their children. After steam engines became a part of the life of society, decorative engines began to be used in universities and schools as educational models.

Modern steam engines

At the beginning of the 20th century, the relevance of steam engines began to decline. One of the few companies that continued to produce decorative mini-engines was the British company Mamod, which allows you to purchase a sample of such equipment even today. But the cost of such steam engines can easily go over two hundred pounds, which is not so little for a trinket for a couple of nights. Moreover, for those who like to assemble all sorts of mechanisms on their own, it is much more interesting to create a simple steam engine with their own hands.

It's very simple. The fire heats up the boiler of water. Under the influence of temperature, the water turns into steam, which pushes the piston. As long as there is water in the tank, the flywheel connected to the piston will rotate. This is the standard design for a steam engine. But you can assemble a model with a completely different configuration.

Well, let's move on from the theoretical part to more fun things. If you are interested in doing something with your own hands, and you are surprised by such exotic cars, then this article is for you, in it we will gladly tell you about different ways how to assemble a steam engine with your own hands. At the same time, the very process of creating a mechanism gives joy no less than its launch.

Method 1: DIY mini steam engine

So, let's begin. Let's assemble the simplest steam engine with our own hands. Drawings, complex tools and special knowledge are not required.

To begin with, we take from under any drink. Cut off the lower third from it. Since the result will be sharp edges, they must be bent inward with pliers. We do this carefully so as not to cut ourselves. Since most aluminum cans have a concave bottom, it will need to be leveled. It is enough to press it firmly with your finger to some hard surface.

At a distance of 1.5 cm from the upper edge of the resulting "glass", it is necessary to make two holes opposite each other. It is advisable to use a hole punch for this, since it is necessary that they turn out to be at least 3 mm in diameter. Put a decorative candle at the bottom of the jar. Now we take ordinary table foil, wrinkle it, and then wrap our mini-burner on all sides.

Mini nozzles

Next, you need to take a piece of copper tube 15-20 cm long. It is important that it is hollow inside, since this will be our main mechanism for setting the structure in motion. The central part of the tube is wrapped around the pencil 2 or 3 times, so that a small spiral is formed.

Now you need to place this element so that the curved place is placed directly above the candle wick. To do this, give the tube the shape of the letter "M". At the same time, we display the sections that go down through the holes made in the bank. Thus, the copper tube is rigidly fixed above the wick, and its edges are a kind of nozzles. In order for the structure to rotate, it is necessary to bend the opposite ends of the "M-element" 90 degrees in different directions. The construction of the steam engine is ready.

Engine starting

The jar is placed in a container with water. In this case, it is necessary that the edges of the tube are under its surface. If the nozzles are not long enough, a small weight can be added to the bottom of the can. But be careful not to sink the entire engine.

Now you need to fill the tube with water. To do this, you can lower one edge into the water, and with the second draw in air like through a tube. We lower the jar into the water. We light the wick of the candle. After a while, the water in the spiral will turn into steam, which, under pressure, will fly out of the opposite ends of the nozzles. The jar will start rotating in the container quickly enough. This is how we got a steam engine with our own hands. As you can see, everything is simple.

Adult Steam Engine Model

Now let's complicate the task. Let's assemble a more serious steam engine with our own hands. First you need to take a paint can. In doing so, you should make sure that it is absolutely clean. Cut a rectangle with dimensions of 15 x 5 cm on the wall 2-3 cm from the bottom. The long side is placed parallel to the bottom of the can. Cut out a piece of 12 x 24 cm from the metal mesh. Measure 6 cm from both ends of the long side. Bend these sections at an angle of 90 degrees. We get a small "platform table" with an area of ​​12 x 12 cm with 6 cm legs. We install the resulting structure on the bottom of the can.

Several holes must be made around the perimeter of the lid and placed in a semicircle shape along one half of the lid. It is desirable that the holes have a diameter of about 1 cm. This is necessary in order to ensure proper ventilation of the interior space. A steam engine will not work well if there is not enough air to reach the fire source.

Main element

We make a spiral from a copper tube. Take about 6 meters of 1/4-inch (0.64 cm) soft copper tubing. We measure 30 cm from one end. Starting from this point, it is necessary to make five turns of a spiral with a diameter of 12 cm each. The rest of the pipe is bent into 15 rings with a diameter of 8 cm. Thus, there should be 20 cm of free pipe at the other end.

Both leads are passed through vents in the lid of the can. If it turns out that the length of the straight section is not enough for this, then one turn of the spiral can be unbend. Coal is placed on a pre-installed platform. In this case, the spiral should be placed just above this platform. Coal is carefully laid out between its turns. The jar can now be closed. As a result, we got a firebox that will power the engine. The steam engine is almost done with our own hands. Left a little.

Water tank

Now you need to take another paint can, but already in a smaller size. A hole with a diameter of 1 cm is drilled in the center of its lid. Two more holes are made on the side of the can - one almost at the bottom, the second higher, near the lid itself.

Take two crusts, in the center of which a hole is made from the diameters of the copper tube. A 25 cm of plastic pipe is inserted into one of the crusts, and 10 cm into the other, so that their edge barely peeks out of the corks. A crust with a long tube is inserted into the lower opening of a small can, and a shorter tube is inserted into the upper opening. Place the smaller can on the large can of paint so that the hole in the bottom is on the opposite side from the ventilation passages of the large can.

Result

As a result, you should get the following construction. Water is poured into a small jar, which flows through a hole in the bottom into copper tube... A fire is kindled under the spiral, which heats up the copper container. Hot steam rises up the tube.

In order for the mechanism to be complete, it is necessary to attach a piston and a flywheel to the upper end of the copper tube. As a result, the thermal energy of combustion will be converted into mechanical forces of rotation of the wheel. There are a huge number of different schemes for creating such an engine. external combustion, but in all of them two elements are always involved - fire and water.

In addition to this design, you can collect steam, but this is material for a completely separate article.

Oftentimes, steam engines or Stanley Steamer cars come to mind at the mention of "steam engines", but the use of these mechanisms is not limited to transportation. Steam engines, which were first created in a primitive form about two millennia ago, have become the largest sources of electrical power over the past three centuries, and today steam turbines produce about 80 percent of the world's electricity. To better understand the nature of the physical forces on the basis of which such a mechanism works, we recommend that you make your own steam engine from ordinary materials using one of the methods suggested here! To get started, go to Step 1.

Steps

Tin can steam engine (for children)

Cut the bottom of the aluminum can at a distance of 6.35 cm. Using metal scissors, cut the bottom of the aluminum can evenly about a third of the height.

Fold and press the bezel down with pliers. To avoid sharp edges, fold the rim of the can inward. Be careful not to injure yourself while doing this.

Press down on the bottom of the can from the inside to flatten it. Most aluminum beverage cans will have a round base and a curved inward. Straighten the bottom by pushing with your finger or using a small flat-bottomed glass.

Punch two holes on opposite sides of the can, 1.3 cm from the top. For making holes, either a paper hole punch or a nail with a hammer will work. You will need holes with a diameter of just over three millimeters.

Place a small tealight candle in the center of the jar. Crumple up the foil and place it underneath and around the candle to keep it from moving. Such candles usually come in special stands, so the wax should not melt and flow into the aluminum can.

Wrap the center piece of copper tubing 15-20 cm long around the pencil 2 or 3 turns to form a coil. The 3mm tube should bend easily around the pencil. You will need enough curved tubing to stretch across the top of the can, plus an additional 5cm straight on each side.

Thread the ends of the tubes through the holes in the jar. The center of the coil should be over the wick of the candle. It is desirable that the straight sections of the tube on both sides of the can be the same length.

Bend the ends of the pipes with pliers to make a right angle. Bend the straight sections of the tube so that they point in opposite directions from opposite sides of the can. Then again fold them down so they drop below the base of the can. When everything is ready, you should get the following: the serpentine part of the tube is located in the center of the can above the candle and turns into two inclined, looking in opposite directions "nozzles" on both sides of the can.

Dip the jar into a bowl of water, while the ends of the tube should be submerged. Your "boat" must be firmly on the surface. If the ends of the tubing are not submerged enough in water, try to make the jar a little heavier, but never sink it.

Fill the tube with water. The most in a simple way will dip one end into the water and pull on the other end like a straw. You can also block one outlet from the tube with your finger, and substitute the other under the stream of water from the tap.

Light a candle. After a while, the water in the tube will heat up and boil. As it turns into steam, it will escape through the "nozzles", causing the entire jar to rotate in the bowl.

Paint can steam engine (for adults)

1. Cut a rectangular hole near the base of the 4 liter paint can. Make a 15 x 5 cm horizontal rectangular hole in the side of the can near the base.

   • Make sure that this can (and the other one used) contains only latex paint, and wash thoroughly with soapy water before use.

2. Cut a 12 x 24 cm strip of metal mesh. Bend 6 cm along the length from each edge at an angle of 90 o. You will have a 12 x 12 cm square platform with two 6 cm legs. Place it in the jar with the legs facing down, aligning it with the edges of the cut hole.

   Make a semicircle of the holes around the perimeter of the lid. Subsequently, you will burn coal in the can to provide heat to the steam engine. If there is a lack of oxygen, the coal will not burn well. To ensure that the jar has the necessary ventilation, drill or punch several holes in the lid that form a semicircle along the edges.

   • Ideally, the diameter of the ventilation holes should be about 1 cm.

3. Make a coil from a copper tube. Take about 6 m of soft copper tubing with a diameter of 6 mm and measure at one end 30 cm.Starting at this point, make five turns with a diameter of 12 cm.Fold the remaining length of the pipe into 15 turns with a diameter of 8 cm.You should have about 20 cm ...

   Pass both ends of the coil through the vents in the cover. Bend both ends of the coil so that they point up and pass both through one of the holes in the cover. If the length of the pipe is not enough, then you will need to slightly unbend one of the turns.

   Place the coil and charcoal in the jar. Place the coil on the mesh platform. Fill the space around and inside the coil with charcoal. Close the cover securely.

   Drill the tubing holes in the smaller can. Drill a 1 cm hole in the center of the lid of a liter can. Drill two 1 cm holes on the side of the can - one near the base of the can, and the other above it near the lid.

   Insert the sealed plastic tube into the side holes of the smaller can. Use the ends of the copper tube to punch holes in the center of the two plugs. Insert a rigid plastic tube 25 cm long into one plug, and the same tube 10 cm long into the other plug. They should sit tightly in traffic jams and look out a little. Insert the plug with the longer tube into the lower hole of the smaller can and the plug with the shorter tube into the upper hole. Secure the tubes to each plug with hose clamps.

   Connect the tube of the larger can to the tube of the smaller can. Place the smaller jar over the larger jar with the tube and stopper facing away from the vents of the larger jar. Using metal tape, secure the tubing from the bottom plug to the tubing coming out of the bottom of the copper coil. Then, in the same way, secure the tube from the top plug with the tube coming out of the top of the coil.

   Insert the copper tube into the junction box. Using a hammer and screwdriver, remove the center section of the round metal electrical box. Secure the cable clamp with the retaining ring. Insert 15 cm of 1.3 cm diameter copper tubing into the cable tie so that the tubing extends a few centimeters below the hole in the box. Blunt the edges of this end inward with a hammer. Insert this end of the tube into the hole in the lid of the smaller jar.

   Insert the skewer into the dowel. Take a regular wooden barbecue skewer and insert it into one end of a 1.5 cm long, 0.95 cm diameter hollow wooden dowel. Insert the dowel with the skewer into the copper tube inside the metal junction box with the skewer pointing up.

   • During the operation of our engine, the skewer and the dowel will act as a "piston". To better see the movement of the piston, you can attach a small paper "flag" to it.

4. Prepare the engine for operation. Remove the junction box from the smaller top jar and fill the top jar with water, letting it pour into the copper coil until the jar is 2/3 full of water. Check all connections for leaks. Secure the jar lids tightly by tapping them with a hammer. Reinstall the junction box over the smaller top jar.

5. Start the engine! Crumple up pieces of newspaper and place them in the space under the net at the bottom of the engine. When the charcoal is lit, let it burn for about 20-30 minutes. As the water heats up in the coil, steam will start to accumulate in the upper can. When the steam has reached sufficient pressure, it will push the dowel and skewer upward. After the pressure is released, the piston will move downward by gravity. If necessary, cut off part of the skewer to reduce the weight of the piston - the lighter it is, the more often it will "pop up". Try to make a skewer of such a weight that the piston "moves" at a constant pace.

   • You can speed up the burning process by increasing the flow of air into the vents with a hairdryer.

6. Observe safety. We believe it goes without saying that care must be taken when working and handling a homemade steam engine. Never run it indoors. Never run it near flammable materials such as dry leaves or overhanging tree branches. Only use the engine on a solid, non-combustible surface such as concrete. If you are working with children or teenagers, then they should not be left unattended. Children and adolescents are prohibited from approaching the engine while charcoal is burning in it. If you do not know the temperature of the engine, then assume that it is so hot that it cannot be touched.

   • Make sure that steam can escape from the upper "boiler". If, for any reason, the piston gets stuck, pressure can build up inside the smaller can. In the worst case scenario, the bank can explode, which very dangerous.
• Place the steam engine in a plastic boat, dipping both ends into the water to create a steam toy. You can cut a simple boat out of a plastic soda bottle or bleach bottle to make your toy more sustainable.

Steam machines were used as drive motor in pumping stations, locomotives, on steam ships, tractors, steam cars and other vehicles. 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 made the latter 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 each time during the cooling of the container, and rather dangerous in operation, since due to high pressure steam containers and engine lines sometimes exploded. Since this device could be used both for rotating the wheels of a water mill, and for pumping water from mines, the inventor called him “the miner's friend”.

Then the English blacksmith Thomas Newcomen in 1712 demonstrated his “ atmospheric 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 working steam pressure. Newcomen may have been based on a description of Papen's experiments in the Royal Society of London, which he may have had access to 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 green, closed - 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 had already been created, driven by the mechanism of the engine itself.

The first in Russia two-cylinder vacuum steam engine was designed by the mechanic I.I.Polzunov in 1763 and built in 1764 to drive 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 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 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 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 car. The self-propelled steam tractor turned out to be very useful as a mobile source of mechanical energy, which set in motion other agricultural machines: threshers, presses, etc. In 1788, a steamboat built by John Fitch was already carrying 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 road competed with its route. In 1802, Scottish engineer William Symington built a competitive steamer, and in 1807, American engineer Robert Fulton used Watt's steam engine to power the first commercially successful steamer. 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 in 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 piston pumps, in any case, there is no evidence that they were used for other purposes. When a vacuum-type steam engine is operating, at the beginning of the stroke, low-pressure steam is admitted into 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 ineffective, 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 water evaporation 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; it did vacuum machines intended for industrial use are too large and expensive.

Compression

The outlet port of the cylinder of the steam engine closes a little earlier than the piston reaches its extreme position, which leaves some of the exhaust steam in the cylinder. This means that there is a compression phase in the cycle of work, 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 the end position, that is, there is some advance of the admission. This advance is necessary so that before the piston begins 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 changes 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 drop 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 arranged 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, in part 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 stringent, and most importantly, such a scheme made it easy to use a condenser that returns waste steam in the form of fresh water back to the boiler (use salt 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 advent 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 drawback 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 window, 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. Straight-through machines single expansion machines show approximately the same efficiency as compounding 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 action.

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 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 machine 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 similar devices that must stop frequently and change direction of rotation.
• Power machines that rarely stop and should not change direction of rotation. These include power engines in power plants, and industrial motors used in factories, factories and cable railways before the widespread use of electric traction. Low power engines are used on ship 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 machines

Steam engines have been used to drive various types of 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 miles 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 terrain 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 from Swiss Locomotive and Machine Works (SLM) models, with many modern improvements such as the use of roller bearings, modern thermal insulation, combustion of light petroleum fractions as fuel, improved steam pipelines, 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 history of the development of the steam engine is described in sufficient detail in this article. There are also the most famous solutions and inventions of the times of 1672-1891.

First developments.

To begin with, as early as the seventeenth century, steam began to be considered as a means of driving, all kinds of experiments were carried out with it, and only in 1643 the forceful action of steam pressure was discovered by Evangelist Torricelli. Christian Huygens, 47 years later, designed the first power machine, powered by an explosion of gunpowder in a cylinder. This was the first prototype of an internal combustion engine. Abbot Otfey's water intake machine is based on a similar principle. Soon, Denis Papin decided to replace the force of the explosion with a less powerful force of steam. In 1690 he built the first steam engine, also known as a steam boiler.

It consisted of a piston, which, with the help of boiling water, moved up in the cylinder and, due to subsequent cooling, dropped again - this was how an effort was created. The whole process took place in this way: a furnace was placed under the cylinder, which simultaneously served as a boiler; when the piston was in the upper position, the furnace was retracted to facilitate cooling.

Later, two Englishmen, Thomas Newcomen and Cowley - one a blacksmith, the other a glazier - improved the system by separating the boiler and cylinder and adding a tank of cold water. This system was operated by valves or taps, one for steam and one for water, which were opened and closed in turn. Then the Englishman Bayton rebuilt the valve control into a truly stroke one.

The use of steam engines in practice.

Newcomen's machine soon became known everywhere and, in particular, was improved by the double-acting system developed by James Watt in 1765. Now Steam engine proved to be complete enough for use in vehicles, although due to its size it was better suited for stationary installations... Watt offered his inventions to industry; he also built machines for textile factories.

The first steam engine used as a vehicle was invented by the Frenchman Nicolas Joseph Cugno, an engineer and amateur military strategist. In 1763 or 1765, he created a car that could carry four passengers at an average speed of 3.5 and a maximum speed of 9.5 km / h. The first attempt was followed by a second - a vehicle appeared for transporting guns. It was tested, of course, by the military, but due to the impossibility of long-term operation (continuous cycle of work new car did not exceed 15 minutes), the inventor did not receive the support of the authorities and financiers. Meanwhile, the steam engine was being improved in England. After several unsuccessful Watt-based attempts by Moore, William Murdoch and William Symington, Richard Travisick's rail vehicle was created for the Welsh Coal Mine. An active inventor came to the world: from underground mines he ascended to earth and in 1802 presented to mankind a powerful a car, reaching a speed of 15 km / h on level ground and 6 km / h on the rise.

Ferry-powered vehicles were increasingly used in the United States: Nathan Reed surprised the Philadelphia residents in 1790 with his steam car model... However, his compatriot Oliver Evans became even more famous, who fourteen years later invented the amphibious car. After the Napoleonic wars, during which "automobile experiments" were not carried out, work began again on invention and improvement of the steam engine... In 1821, it could be considered perfect and reliable enough. Since then, every step forward in the field of steam-powered vehicles has definitely contributed to the development of future cars.

In 1825 Sir Goldsworth Garney organized the first passenger line on a 171 km stretch from London to Bath. In doing so, he used a carriage patented by him, which had a steam engine. This was the beginning of the era of high-speed road carriages, which, however, disappeared in England, but became widespread in Italy and France. Such vehicles reached their highest development with the appearance in 1873 "Reverance" Amede Balle weighing 4500 kg and "Mansel" - more compact, weighing just over 2500 kg and reaching a speed of 35 km / h. Both were forerunners of the performance technique that became characteristic of the first "real" cars. Despite the great speed steam engine efficiency was very small. Bolle was the one who patented the first well-functioning steering system, and he arranged the steering and control elements so well that we still see it on the dashboard today.

Despite the tremendous progress in the field of the internal combustion engine, the steam power still provided a more even and smoother machine running and, therefore, had many supporters. Like Bolle, who built other light cars, such as the Rapide in 1881 with a speed of 60 km / h, the Nouvelle in 1873, which had a front axle with independent wheel suspension, Leon Chevrolet launched several cars between 1887 and 1907. with a lightweight and compact steam generator, patented by him in 1889. The company De Dion-Bouton, founded in Paris in 1883, produced cars with steam engines for the first ten years of its existence, and at the same time achieved significant success - its cars won the Paris-Rouen race in 1894.

The success of Panhard et Levassor in the use of gasoline led, however, to the fact that De Dion also switched to internal combustion engines. When the Bolle brothers took over their father's company, they did the same. Then the Chevrolet company rebuilt its production. Steam-powered cars were disappearing from the horizon faster and faster, although they were in use in the United States even before 1930. At this very moment, production stopped and invention of steam engines

I came across an interesting article on the Internet.

"American inventor Robert Green has developed a completely new technology that generates kinetic energy by converting residual energy (like other fuels). Green's steam engines are piston-powered and designed for a wide variety of applications."
That's it, no more, no less: a completely new technology. Well, of course I began to look, tried to understand. It is written everywhere one of the most unique advantages of this engine is the ability to generate energy from the residual energy of the engines. More specifically, the residual exhaust energy from the engine can be converted to energy going to the pumps and cooling systems of the unit. So what of this, as I understand it exhaust gases bring water to a boil and then convert the steam into motion. How necessary and cost-effective, because ... even though this engine, as they say, is specially designed from a minimum number of parts, but still it costs so much and is there any sense in fencing a garden, all the more fundamentally new in this invention I do not see ... And a lot of mechanisms for converting reciprocating motion into rotational motion have already been invented. On the author's website, the two-cylinder model is sold, in principle, not expensive
only $ 46.
On the author's website there is a video using solar energy, there is also a photo of someone on a boat using this engine.
But in both cases, this is clearly not residual heat. In short, I doubt the reliability of such an engine: "Ball bearings are at the same time hollow channels through which steam is supplied to the cylinders." What is your opinion, dear site users?
Articles in Russian