Steam engine

piston and cylinder of an atmospheric steam engine
atmospheric steam engine after Newcomen
Aeolipile, first steam engine after Heron of Alexandria
Watt'sche Niederdruckdampfmaschine
Watt' low pressure steam engine
support steam engine of 1864
Förderdampfmaschine einer Kohlenzeche
promotion steam engine of a coal bill
Die Dampfmaschine im Wülfing-Museum mit einer Leistung von über 300 PS
the steam engine in the Wülfing museum with an achievement of over 300 HP
Pumpenhaus der ersten Dampfmaschine in Pumpe-Stich 1793
pump house firstSteam engine in pump pass 1793

a steam engine is a thermal engine, the heat energy partly into mechanical work converts. Today the industrially spread design is the steam turbine. Under a “steam engine” however above all the piston steam engine becomes, a steam-driven in German Piston engine, understood, which it concerns in this article. The steam engine was the first prime mover, which was operated with fossil fuels in the form of hard coal.

Table of contents

impact of a piston steam engine

the piston steam engine converts thermodynamic energy (steam pressure) into mechanical Rotationsenergie. A piston in the associated cylinder moves back and forth, it leadsa reciprocating movement out. For the mechanical Nutzenergie however mostly a rotation is needed.

The movement of the piston is implemented with pressure of steam as clock rate. The return motion is implemented with on one side subjected piston from stored rotation momentum energy. With bilateralsubjected piston however is likewise performed the return motion of the piston as clock rate, by steam pressure control now on the lower surface of the piston.

The Dampfzufuhr into the cylinder steers a slidegate valve. The piston becomes with the pressure only downward and/or. inDirection of the crankshaft shifted. The linear movement of the piston is converted by means of crosshead and piston rod as coupling element at the crankpin of the crankshaft into a rotation. The piston rod pushes afterwards (in the one-sided enterprise) with in the flywheel and in the crankshaft stored Rotationsenergiethe pistons the lower situation linear back into its upper starting position.

The working procedure of a steam engine is arranged thus into two clocks and is therefore a secondary act procedure.

Atmospheric steam engine

in an atmospheric steam engine becomes the cylinder space under that Piston filled with water vapour, which is then cooled down up to the condensation. Thereupon the piston is pressed by the outside atmospheric pressure into the cylinder. The driving out movement of the piston takes place from the outside, for example via a rotor.

The most well-known representative of this designthe atmospheric steam engine of Thomas Newcomen was starting from 1712 (S. and)

Low pressure steam engine

with a low pressure steam engine presses additionally steam with some 100 mbar positive pressure on the other side of the piston. The piston affect thereby positive pressure plus atmospheric pressure, which the efficiencyincreased. The most well-known representatives of this design were the steam engines of James Watt starting from approximately 1769 (S. and).

High pressure steam engine

with high pressure steam engines is warmed up steam well over 100 °C, so that a higher pressure constructs itself. On a cooling outcan to the cylinder of withdrawing water vapour be done without (exhaust enterprise). The condenser can be omitted thus, what makes this type of machine in connection with the higher power density of steam which is at pressure substantially easier and made possible thus the use of steam engines in steam engines only.Representatives of this design are practically all piston steam engines in vehicles since smelling pool of broadcasting corporations Trevithick starting from approximately 1802 (S. and).

History of the steam engine

the first equipment propelled by steam became from the Greek Heron of Alexandria in the 1. Century invented, but only asPlaything uses (Aeolipile). Some further attempts, which did not find all a large application, followed among other things from Denis Papin 1690 and Thomas Savery 1698.

The first usable steam engine was designed 1712 by Thomas Newcomen and served forEvacuate the water in a mine. This atmospheric steam engine in such a way specified produced a negative pressure by injecting water into a cylinder filled with steam in relation to the atmosphere. With this difference of pressure the piston in the clock rate of the atmospheric air pressure became afterdown pressed and afterwards by the dead weight of the Pumpenstange which can be propelled again upward into the starting position pulled. The power transmission between piston rod and balance took place by means of a chain. The efficiency of the Newcomen machine was with 0,5 per cent.

James Watt,to that often falsely one attributes the invention of the steam engine, improved the efficiency of the Newcomen' steam engine substantially, by shifting the cooling procedure from the cylinder starting from 1769 on the one hand into a separate condenser, on the other hand the pistons alternating of the one andthe other side with steam fed - and on the side facing in each case the discharge opening to the condenser opened. So Watt without mechanical reconducting of the piston, and let the machine could do with both piston strokes work perform. Together with thatInvention of the Watt' parallelogram was possible it to be moveable the machine a flywheel. James Watt called this invention its most important; it is also today still considered as example to the solution of the task, a circular movement into a straight-lineto convert only by swivel joints.

James Watt is considered as a discoverer of the use of the steam expansion. With the steam engine this effect is reached by premature closing of the valves; thus the supply of steam is interrupted into the cylinder, duringthe steam of far work included in it carries out. Further James Watt introduced the centrifugal governor for the speed control of its machine. This mechanical component had been already inserted before with the building and enterprise by mills.

In order to demonstrate the ability of its steam engines, Watt inventedthe unit of power horse power.

The wattsche steam engine saved a multiple of the heat energy, which was necessary for the enterprise of the machine by these improvements opposite its predecessors. The efficiency of the Watt' machine reached finally 3.0 per cent.

With its commercial partner Matthew Boultonsold it its machines however not, but put it to its customers at the disposal, in order to be able to be disbursed a part of the saved fuel costs. Thus an early form of the machine leasing was born.

The high pressure steam engine was designed 1784 of olive Evans. Thatfirst copy was built by him however only 1812. It came before smelling pool of broadcasting corporations Trevithick, which built 1801 the first high pressure steam engine into a road vehicle. A condition for the operability of the high pressure steam engines was the progress in the metal production and - treatment to thisTime, because in printing machines the machine parts must sit very properly matching. In addition the danger of the explosion of the boiler existed.

Where the first steam engine of Germany stood, is contentious. One of the first steam engines of Germany stood 1793 in Eschweiler. 1803 built Franz Dinnendahlthe first steam engine in the Ruhr district. Manufactured in England, it was taken to Langendreer on the bill full moon in Bochum - in enterprise. In the one field museum the first German steam engine is located to Watt design, those on the king Friedrich pit with Hettstedt in the year 1785 in enterpriseone took. The machine can be demonstrated in motion. Also the oberschlesische Tarnowitz suns itself in this fame. Here became alleged to 19. January 1788 the first steam engine on the European mainland taken in enterprise. It served that for the drainageTarnowitzer of mines.

With these developments steam engines became starting from the second half 18. Century now also economically.

The continuous advancement of the pressure-claimant steam engine, which worked first with “saturated steam so mentioned “, led across the einzylindrige superheated steam machine to the two orthree-cylindrical Compound machine and last to the more-cylindrical superheated steam high pressure steam engine, as it was offered by Kemna. With the Sattdampfmaschine it is in the boiler all Siederohre for the steam generation in the water bed, the superheated steam machine possesses a second Röhrensystem that of the fire or the hot flue gasesone coats. Thus steam “is spanned” and reaches temperatures by 350 degrees Celsius. The Compound machine or group machine possesses a high pressure cylinder with small drilling and one or more (n) low pressure cylinders switched into series. As superheated steam into the high pressure cylinder the fed, nowpart-eased and cooler escaping steam has still enough work abilities, in order to operate the low pressure cylinder provided with a substantially larger drilling. It is tried to co-ordinate the Zylinderbohrungen in such a way that the produced torque of both cylinders is about alike on the crankshaft.Also the volume of both cylinders must be co-ordinated with the number of revolutions of the steam engine, so that the relaxation of steam is distributed on both cylinders. There were Compound machines in the synchronisation (both piston rods go at the same time into the same direction) and in the Gegenlauf (Kurbelwellenkröpfungby 180 degrees shifts). Kemna built starting from 1908 steam engines with 2 high pressure cylinders.

The best machines had already around 1910 a very high efficiency and reached with hard coal of middle quality a consumption of approximately 0.5 kg/HP-grant.

Early applications of the steam engines founditself in the textile industry to the drive of textile machines and in the mining industry to the dewatering. Steam engines , steam ships as well as Lokomobilen and truck followed. Also the first airship was propelled 1852 by a steam engine. The industrielle revolution became by thoseSteam engine only makes possible.

Modern times

pattern of one triple expansion steam engine

as vehicle drive steam engines were replaced by combustion engines, which start without preheating time, a higher efficiency have, larger achievement with smaller weight to offer to a large extent and more comfortably serve are. Further the steam engine haslost their function as central energy source of an industrial enterprise by the surface covering supply of electricity, which held it long time. In the hard coal mining and still steam engines are used in conveyor plants, because there the steam engine knows both and hoisting engine for liftingfrom coal and as brake for letting down disalignment material serve. When braking the energy is used for the heating of steam.

Although the time of the piston steam engine seems to be for a long time past, one Renaissance is not impossible. One of their advantagesopposite the combustion engine is their continuous Verbrennungsvorgang, which can be arranged more emissionsärmer. A further advantage of the steam engine is their extreme overload capacity with the demand of Leistungsspitzen. As a result of the today usual closed cycle of steam and feed water one arisesemissionsarme lubrication of cylinder and piston of the machine. In this sense as modernized steam engine the steam engine was developed.

On behalf Volkswagen AG the IAV GmbH developed such a modern “steam engine” into the late 1990er years, overan extremely emission-free external burn a certain supply of high-pressure steam produces, which is then injected as with the diesel engine over nozzles depending upon power requirement. At the end of of 2000 came out from this the company Enginion and has from the ZEE (Zero emission engine) - prototypesthe today's „SteamCell “develops further. In addition this machine works in the secondary act procedure, is practically emission-free and gets along without usual lubricants, because the wearing parts from modern carbon components are manufactured.

See also

Resuming literature

  • Heinrich Dubbel, sketching and calculation of the steam engines, 2. improved edition, Berlin, Springer 1907
  • F. Merrily, piston steam engines, in: Dubbels paperback for mechanical engineering, 11. edition worked on 1953, second completely again volumes, S.93ff
  • Conrad Matschoss, history of the steam engine:its cultural meaning, technical. Development and. their large men, 3. Aufl. Berlin 1901, Reprint: Gerstenberg, Hildesheim, ISBN 3806707200
  • technology easily understandably specialized editorship technology of the bibliographic institute under the direction of Johannes Kunsemüller, torch/flare book club
  • Lucian Haas, Tim Schröder, Monika wow,Movement signals machines and worlds (brochure for the year of the technology), Bonn: Federal Ministry for education and research, 2004, Download:http://www.bmbf.de/pub/bewegungssignale_maschinen_und_welten.pdf
  • Sigvard Strandh, the machine, history - elements - function, Freiburg in mash gau [among other things]: Herder, 1980, ISBN 3-451-18873-2
  • Otfried Wagenbreth,Helmut Düntzsch, Albert Gieseler, the history of the steam engine, Aschendorff publishing house, Münster 2001, ISBN 3-402-05264-4
  • Gerhard shrub man, harsh ore Clemens, Michael Hoetger, Bertold Mayr, the steam engine - level of development and market chances, special edition from MTZ engine-technical magazine 05/2001, 62. Class, Friedr. Vieweg& son, Verlagsges. ltd., Wiesbaden

off print from MTZ engine-technical magazine of 62/2001 - volume. 5, Friedr. Vieweg & son, Verlagsges. ltd., Wiesbaden

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