Steam locomotives, the device of which is primitive against other technologies today, are still used in some countries. They are autonomous locomotives using a steam engine as an engine. The very first such locomotives appeared in the 19th century and played a key role in the formation of the economy of a number of countries.
The device of the engine was constantly improved, as a result of which new designs appeared that were very different from the classic. So there were models with gears, turbines, without a tender.
Today, the arrangement of a steam locomotive can be considered obsolete, since in the middle of the 20th century diesel locomotives and electric locomotives were created - more economical locomotives. Although, as already mentioned, even now steam engines continue to work.
Principle of operation and arrangement of a steam locomotive
Despite the fact that there are various modifications of the structures of this transport, they all have three main parts:
- steam engine;
- boiler;
- crew.
Steam is produced in a steam boiler - it is this unit that is the primary source of energy, and steam is the main working fluid. In a steam engine, it is converted into a reciprocating mechanical movement of the piston, which, in turn, is transformed into a rotary mechanism using a crank mechanism. Due to this, the wheels of the engine rotate. Also, steam drives a steam air pump, a steam turbine generator and is used in whistle.
The crew of the car consists of a running gear and a frame and is a mobile base. These three elements are fundamental in the design of the engine. Also, a tender - a carriage, which serves as a storage of coal (fuel) and water, can adjoin the car.
Steam boiler
When considering the device and the principle of operation of the engine, you need to start with the boiler, as this is the primary source of energy and the main component of this machine. There are certain requirements for this element: reliability and safety. The vapor pressure in the installation can reach 20 atmospheres or more, which makes it practically explosive. Malfunctioning of any element of the system can lead to an explosion, which will deprive the machine of a source of energy.
Also, this element should be convenient in management, repair, maintenance, be flexible, that is, be able to work with different fuels (more or less powerful).
Firebox
The main element of the boiler is the firebox, where solid fuel is burned, which is supplied by means of a coal feeder. If the machine runs on liquid fuel, then it is fed through nozzles. High-temperature gases released as a result of combustion transfer heat through the walls of the fire box to water. Then the gases, having given most of the heat to evaporate the water and heat the saturated steam, are discharged into the atmosphere through the chimney and spark arrestor.
The steam formed in the boiler is accumulated in the dry-hood (in the upper part). When the vapor pressure exceeds 105 Pa, a special safety valve releases it, releasing excess into the atmosphere.
Hot steam under pressure is supplied through pipes to the cylinders of the steam engine, where it presses on the piston and crank mechanism, leading to rotation of the drive axle. The exhaust steam enters the chimney, creating a vacuum in the chimney, which increases the air flow into the boiler furnace.
Scheme of work
That is, if you describe the principle of work in a general way, everything seems extremely simple. What the layout of the steam locomotive’s device looks like can be seen in the photo posted in the article.
The steam boiler burns fuel that heats the water. Water is converted to steam, and as it warms up, the vapor pressure in the system increases. When it reaches a high value, it is fed into the cylinder, where the pistons are located.
Due to the pressure on the pistons, the axis rotates and the wheels are driven. Excess steam is released into the atmosphere through a special safety valve. By the way, the role of the latter is extremely important, because without it the boiler would burst from the inside. This is what the steam boiler boiler looks like.
Benefits
Like other types of locomotives, locomotives have certain advantages and disadvantages. The advantages are as follows:
- Simplicity of design. Due to the simple arrangement of the steam engine of the steam locomotive and its boiler, it was not difficult to establish production at machine-building and metallurgical plants.
- Reliability in work. The mentioned simplicity of design provides high reliability of the entire system. There is practically nothing to break, because of which the locomotives have been working for 100 years or more.
- Powerful traction when starting.
- The ability to use different types of fuel.
Previously, there was such a thing as omnivorous. It was applied to steam locomotives and determined the ability to use wood, peat, coal, fuel oil as fuel for this machine. Sometimes locomotives were heated with production waste: various sawdust, grain husk, wood chips, defective grain, and used lubricants.
Of course, the traction capabilities of the machine were reduced, but in any case, this saved considerable funds, since classic coal is more expensive.
disadvantages
It was not without drawbacks either:
- Low efficiency. Even on the most advanced steam locomotives, the efficiency was 5–9%. This is logical, given the low efficiency of the steam engine itself (about 20%). Inefficiency of fuel combustion, large heat loss during the transfer of steam heat from the boiler to the cylinders.
- The need for huge reserves of fuel and water. This problem became especially urgent when operating machines in arid areas (in deserts, for example), where it is difficult to get water. Of course, steam engines with condensation of exhaust steam were invented a little later, however, this did not solve the problem completely, but only simplified it.
- Fire hazard due to open fire of burning fuel. This drawback is absent on fuelless steam locomotives, but their range is limited.
- Smoke and soot emitted into the atmosphere. This problem becomes serious when steam locomotives move within settlements.
- Difficult conditions for the team that serves the car.
- The complexity of the repair. If something fails in the steam boiler, the repair takes a long time and requires investment.
Despite the shortcomings, steam locomotives were very much appreciated, since their use significantly increased the level of industry in different countries. Of course, today the use of such machines is not relevant, due to the presence of more modern internal combustion engines and electric motors. Nevertheless, it was the locomotives that laid the foundation for the creation of railway transport.
Finally
Now you know the design of the engine of the engine, its features, the pros and cons of operation. By the way, today on the highways of underdeveloped countries (for example, in Cuba), these machines are still used. Until 1996, they were used in India. In European countries, USA, Russia, this type of transport exists only in the form of monuments and museum exhibits.