Stirling engine - Revision history

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2018-06-25T14:30:30Z

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Jmdonev at 01:36, 9 June 2018

2018-06-09T01:36:14Z

← Older revision		Revision as of 01:36, 9 June 2018
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	[[Category:Done ~~2015~~-09-05]]		[[Category:Done 2018-06-15]]
	[[File:Gotland.jpg\|300px\|thumb\|Figure 1. Gotland class submarines ~~are the first to~~ use Stirling engines.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://en.wikipedia.org/wiki/Gotland-class_submarine#/media/File:Swedish_attack_submarine_HMS_Gotland.jpg</ref>]]		[[File:Gotland.jpg\|300px\|thumb\|Figure 1. Gotland class submarines use Stirling engines.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://en.wikipedia.org/wiki/Gotland-class_submarine#/media/File:Swedish_attack_submarine_HMS_Gotland.jpg</ref>]]

	<onlyinclude>'''Stirling engines''' are a type of [[reciprocating engine\|reciprocating]] [[external heat engine]] that uses one or more [[piston]]s to achieve useful [[work]] through some input of [[heat]] from an [[external combustion engine\|external]] source. They differ vastly from [[internal combustion engine]]s that are seen in most vehicles.</onlyinclude> Stirling engines use the same [[gas]] over and over, unlike internal combustion engines which constantly intake and exhaust the gas. Also, Stirling engines do not use explosions like normal [[gasoline]] engines, therefore they are very quiet.<ref name=hsw>How Stuff Works, ''How Stirling Engines Work'' [Online], Available: http://auto.howstuffworks.com/stirling-engine.htm</ref>		<onlyinclude>'''Stirling engines''' are a type of [[reciprocating engine\|reciprocating]] [[external heat engine]] that uses one or more [[piston]]s to achieve useful [[work]] through some input of [[heat]] from an [[external combustion engine\|external]] source. They differ vastly from [[internal combustion engine]]s that are seen in most vehicles.</onlyinclude> Stirling engines use the same [[gas]] over and over, unlike internal combustion engines which constantly intake and exhaust the gas. Also, Stirling engines do not use explosions like normal [[gasoline]] engines, therefore they are very quiet.<ref name=hsw>How Stuff Works, ''How Stirling Engines Work'' [Online], Available: http://auto.howstuffworks.com/stirling-engine.htm</ref>

	Although these seem like major advantages to an ordinary engine, they ~~lack practicality~~ in ~~everyday~~ vehicles because they require external heat, rather than internal heat. ~~Because~~ of ~~this, it takes~~ extra time for the heat ~~to reach~~ the inside of the engines ~~which~~ makes the engine far less responsive than internal combustion engines.<ref name=hsw/> Stirling engines have also been found to be largely impractical in [[power plant]]s; Stirling engines have low [[specific power]], meaning that the engine has to be quite large in order to produce a relatively small amount of power.<ref>Electropaedia, ''The Stirling Engine'' [Online], Available: http://www.mpoweruk.com/stirling_engine.htm</ref>		Although these seem like major advantages to an ordinary engine, they are less practical in most vehicles because they require ''external'' heat, rather than ''internal'' heat. The external source of hit needs extra time for the heat get the inside of the engines. This heat transfer makes the engine far less responsive than internal combustion engines.<ref name=hsw/> Stirling engines have also been found to be largely impractical in [[power plant]]s; Stirling engines have low [[specific power]], meaning that the engine has to be quite large in order to produce a relatively small amount of power.<ref>Electropaedia, ''The Stirling Engine'' [Online], Available: http://www.mpoweruk.com/stirling_engine.htm</ref>

	==Operation==		==Operation==

	The key unique characteristic of Stirling engines is that there is a '''fixed amount of gas inside'''.<ref name=hsw/> ~~This~~ gas can be manipulated by ~~''increasing'' [[pressure]] through~~ adding heat and ~~raising its [[~~temperature~~]] and by ''decreasing''~~ pressure ~~through removal of heat~~ and ~~decreasing its~~ temperature. By changing how these two processes are done, the engine can be made to deliver useful work. The engine follows the "Stirling cycle" ~~which we will describe~~ in a general form and can be seen in Figure 2. The cycle is as follows:<ref name=hsw/>		The key unique characteristic of Stirling engines is that there is a '''fixed amount of gas inside'''.<ref name=hsw/> The pressure of the gas can be manipulated by adding or removing heat. Adding heat will increase the pressure (and temperature)—in contrast, removing heat will decrease the pressure (and temperature). By changing how these two processes are done, the engine can be made to deliver useful work. The engine follows the "Stirling cycle" described below in a general form and can be seen in Figure 2. The cycle is as follows:<ref name=hsw/>

	#'''Heating and expansion'''- Heat is input from an external source, raising the temperature and therefore pressure of the gas. This causes a piston to expand and provide '''useful work.'''		#'''Heating and expansion'''- Heat is input from an external source, raising the temperature and therefore pressure of the gas. This causes a piston to expand and provide '''useful work.'''
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	[[File:EuroDishSBP_front.jpg\|200px\|thumb\|Figure 3. A Stirling engine, as seen in the center of this parabolic mirror, can be heated by the Sun.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://upload.wikimedia.org/wikipedia/commons/e/ed/EuroDishSBP_front.jpg</ref>]]		[[File:EuroDishSBP_front.jpg\|200px\|thumb\|Figure 3. A Stirling engine, as seen in the center of this parabolic mirror, can be heated by the Sun.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://upload.wikimedia.org/wikipedia/commons/e/ed/EuroDishSBP_front.jpg</ref>]]
	[[File:MM-7_Stirling_Engine.jpg\|200px\|thumb\|Figure 4. A Low temperature differential (LTD) Stirling engine, can generate around 1 W of power from a person's palm.<ref>~~Wikimedia Commons~~ [~~Online].~~ (~~June 4 2015). Available:~~ http://~~upload~~.~~wikimedia~~.org/~~wikipedia~~/~~commons~~/e/ed/~~EuroDishSBP_front~~.~~jpg~~</ref>]]		[[File:MM-7_Stirling_Engine.jpg\|200px\|thumb\|Figure 4. A Low temperature differential (LTD) Stirling engine, can generate around 1 W of power from a person's palm.<ref>By Arsdell [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons</ref>]]

	*'''Cogeneration''' ('''CHP''')- In a [[cogeneration]] unit, a Stirling engine can make use of [[waste heat]] that is produced due to the [[second law of thermodynamics]]. This waste heat can go towards powering the Stirling engine for industrial or agricultural processes.		*'''Cogeneration''' ('''CHP''')- In a [[cogeneration]] unit, a Stirling engine can make use of [[waste heat]] that is produced due to the [[second law of thermodynamics]]. This waste heat can go towards powering the Stirling engine for industrial or agricultural processes.
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	The U.S. has also developed a Stirling engine to generate electricity for use in space exploration.		The U.S. has also developed a Stirling engine to generate electricity for use in space exploration.

			==For Further Reading==
			*[[External combustion engine]]
			*[[Heat engine]]
			*[[Solar power]]
			*[[Nuclear power]]
			*[[Cogeneration]]
			*Or explore a [[Special:Random\|random page]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

J.williams: 1 revision imported

2015-09-03T18:23:00Z

1 revision imported

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Jmdonev at 23:53, 28 August 2015

2015-08-28T23:53:59Z

← Older revision		Revision as of 23:53, 28 August 2015
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	[[Category:Done 2015-06-11]]		[[Category:Done 2015-09-05]]
	[[File:Gotland.jpg\|300px\|thumb\|Figure 1. Gotland class submarines are the first to use Stirling engines.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://en.wikipedia.org/wiki/Gotland-class_submarine#/media/File:Swedish_attack_submarine_HMS_Gotland.jpg</ref>]]		[[File:Gotland.jpg\|300px\|thumb\|Figure 1. Gotland class submarines are the first to use Stirling engines.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://en.wikipedia.org/wiki/Gotland-class_submarine#/media/File:Swedish_attack_submarine_HMS_Gotland.jpg</ref>]]

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	*'''Solar power generation'''- Placed at the focus of a parabolic mirror as seen in Figure 2, Stirling engines can convert [[solar energy]] to [[electricity]] with an [[efficiency]] better than some [[photovoltaic cell]]s.		*'''Solar power generation'''- Placed at the focus of a parabolic mirror as seen in Figure 2, Stirling engines can convert [[solar energy]] to [[electricity]] with an [[efficiency]] better than some [[photovoltaic cell]]s.

	*'''Submarines'''- Stirling powered ~~[[submarine]]s~~ can stay submerged much longer than conventional submarines. Swedish ship builder Kockums first installed Stirling engines in submarines, and with them the submarine doesn't have to surface to recharge its batteries, extending its submersion from days to weeks.<Ref>Saab. (June 4, 2015). ''The Stirling Engine'' [Online]. Available: http://saab.com/naval/Submarines-and-Warships/technologies/The-Stirling-Engine/</ref>		*'''Submarines'''- Stirling powered submarines can stay submerged much longer than conventional submarines. Swedish ship builder Kockums first installed Stirling engines in submarines, and with them the submarine doesn't have to surface to recharge its batteries, extending its submersion from days to weeks.<Ref>Saab. (June 4, 2015). ''The Stirling Engine'' [Online]. Available: http://saab.com/naval/Submarines-and-Warships/technologies/The-Stirling-Engine/</ref>

	*'''Nuclear power plants'''- There is potential for Stirling engines to replace [[steam]] [[turbine]]s in [[nuclear reactor]]s, and could increase the plant's efficiency and reduce radioactive by-products. These would use liquid sodium as coolant, and remove the need for [[water]] anywhere in the cycle.<ref name=nuc/>		*'''Nuclear power plants'''- There is potential for Stirling engines to replace [[steam]] [[turbine]]s in [[nuclear reactor]]s, and could increase the plant's efficiency and reduce radioactive by-products. These would use liquid sodium as coolant, and remove the need for [[water]] anywhere in the cycle.<ref name=nuc/>

J.williams: 1 revision imported

2015-08-26T21:31:41Z

1 revision imported

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J.williams at 16:59, 12 August 2015

2015-08-12T16:59:08Z

New page

[[Category:Done 2015-06-11]]
[[File:Gotland.jpg|300px|thumb|Figure 1. Gotland class submarines are the first to use Stirling engines.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://en.wikipedia.org/wiki/Gotland-class_submarine#/media/File:Swedish_attack_submarine_HMS_Gotland.jpg</ref>]]

<onlyinclude>'''Stirling engines''' are a type of [[reciprocating engine|reciprocating]] [[external heat engine]] that uses one or more [[piston]]s to achieve useful [[work]] through some input of [[heat]] from an [[external combustion engine|external]] source. They differ vastly from [[internal combustion engine]]s that are seen in most vehicles.</onlyinclude> Stirling engines use the same [[gas]] over and over, unlike internal combustion engines which constantly intake and exhaust the gas. Also, Stirling engines do not use explosions like normal [[gasoline]] engines, therefore they are very quiet.<ref name=hsw>How Stuff Works, ''How Stirling Engines Work'' [Online], Available: http://auto.howstuffworks.com/stirling-engine.htm</ref>

Although these seem like major advantages to an ordinary engine, they lack practicality in everyday vehicles because they require external heat, rather than internal heat. Because of this, it takes extra time for the heat to reach the inside of the engines which makes the engine far less responsive than internal combustion engines.<ref name=hsw/> Stirling engines have also been found to be largely impractical in [[power plant]]s; Stirling engines have low [[specific power]], meaning that the engine has to be quite large in order to produce a relatively small amount of power.<ref>Electropaedia, ''The Stirling Engine'' [Online], Available: http://www.mpoweruk.com/stirling_engine.htm</ref>

==Operation==

The key unique characteristic of Stirling engines is that there is a '''fixed amount of gas inside'''.<ref name=hsw/> This gas can be manipulated by ''increasing'' [[pressure]] through adding heat and raising its [[temperature]] and by ''decreasing'' pressure through removal of heat and decreasing its temperature. By changing how these two processes are done, the engine can be made to deliver useful work. The engine follows the "Stirling cycle" which we will describe in a general form and can be seen in Figure 2. The cycle is as follows:<ref name=hsw/>

#'''Heating and expansion'''- Heat is input from an external source, raising the temperature and therefore pressure of the gas. This causes a piston to expand and provide '''useful work.'''
#'''Flow and cooling'''- The piston moves up forcing the gas into another cylinder, where it is cooled. The cooling of the gas allows for easier compression, which means that less work is needed than was produced in step 1.
#'''Compression'''- The gas is now compressed, and the excess heat created from this compression is removed by the cooling source.
#'''Reverse flow and heating'''- The compressed gas moves back into the initial chamber where the cycle repeats.

[[File:Sterlingcycle.png|800px|center|thumb|Figure 2. Basic ideal Sterling cycle.<ref>''Made internally by a member of the Energy Education team''</ref>]]

The Stirling cycle can give more power by having a hotter source of heat in step 1, or by having a cooler cold sink in step 2.

[http://stirlingshop.com/html/stirlingengines_types.html Click here] to learn about the different types of Stirling engines.

==Application==

Stirling engines have many applications:<ref name=nuc>Stirling Shop. (June 4, 2015) ''Stirling engine - Applications'' [Online]. Available: http://stirlingshop.com/html/applications_.html</ref>

[[File:EuroDishSBP_front.jpg|200px|thumb|Figure 3. A Stirling engine, as seen in the center of this parabolic mirror, can be heated by the Sun.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://upload.wikimedia.org/wikipedia/commons/e/ed/EuroDishSBP_front.jpg</ref>]]
[[File:MM-7_Stirling_Engine.jpg|200px|thumb|Figure 4. A Low temperature differential (LTD) Stirling engine, can generate around 1 W of power from a person's palm.<ref>Wikimedia Commons [Online]. (June 4 2015). Available: http://upload.wikimedia.org/wikipedia/commons/e/ed/EuroDishSBP_front.jpg</ref>]]

*'''Cogeneration''' ('''CHP''')- In a [[cogeneration]] unit, a Stirling engine can make use of [[waste heat]] that is produced due to the [[second law of thermodynamics]]. This waste heat can go towards powering the Stirling engine for industrial or agricultural processes.

*'''Solar power generation'''- Placed at the focus of a parabolic mirror as seen in Figure 2, Stirling engines can convert [[solar energy]] to [[electricity]] with an [[efficiency]] better than some [[photovoltaic cell]]s.

*'''Submarines'''- Stirling powered [[submarine]]s can stay submerged much longer than conventional submarines. Swedish ship builder Kockums first installed Stirling engines in submarines, and with them the submarine doesn't have to surface to recharge its batteries, extending its submersion from days to weeks.<Ref>Saab. (June 4, 2015). ''The Stirling Engine'' [Online]. Available: http://saab.com/naval/Submarines-and-Warships/technologies/The-Stirling-Engine/</ref>

*'''Nuclear power plants'''- There is potential for Stirling engines to replace [[steam]] [[turbine]]s in [[nuclear reactor]]s, and could increase the plant's efficiency and reduce radioactive by-products. These would use liquid sodium as coolant, and remove the need for [[water]] anywhere in the cycle.<ref name=nuc/>

*'''Educational demonstration'''- A low temperature difference Stirling engine will run on any low temperature difference, for example the difference between the palm of a hand as seen in Figure 4.

The U.S. has also developed a Stirling engine to generate electricity for use in space exploration.

==References==
{{reflist}}
[[Category:Uploaded]]