Changes

===Vapor absorption cycle===

===Vapor absorption cycle===

The first cyclic refrigeration system used the vapor absorption cycle.  Since then, it has become much less common in modern refrigeration, since it is less effective than vapor compression (it has a low coefficient of performance). The vapor absorption cycle does not use very much electricity compared to other methods, but does require plenty of heat.

The first cyclic refrigeration system used the vapor absorption cycle.  Since then, it has become much less common in modern refrigeration, since it is less effective than vapor compression (it has a low coefficient of performance). The vapor absorption cycle does not use very much electricity compared to other methods, but does require plenty of heat.

The key to this process is ammonia, which is used as the refrigerant.  Ammonia easily dissolves into water, which is why this specific substance is so important.  The main difference between this and the modern norm--vapor compression--is the compressor, or specifically for vapor absorption, the lack of one.  Rather than a mechanical compressor, this method uses an absorber which contains [[water]].<ref name="brighthubengineering apor-absorption-cycle">http://www.brighthubengineering.com/hvac/20355-methods-of-refrigeration-vapor-absorption-cycle</ref> Here is the process: <!--sounds choppy.  Improve flow?-->

The key to this process is ammonia, which is used as the refrigerant.  Ammonia easily dissolves into water, which is why this specific substance is so important.  The main difference between this and the modern norm—vapor compression—is the compressor, or specifically for vapor absorption, the lack of one.  Rather than a mechanical compressor, this method uses an absorber which contains [[water]].<ref name="brighthubengineering apor-absorption-cycle">http://www.brighthubengineering.com/hvac/20355-methods-of-refrigeration-vapor-absorption-cycle</ref> Here is the process: <!--sounds choppy.  Improve flow?-->

#Gaseous ammonia is first pushed into the absorber, where it dissolves into the water.  It is somewhat pressurized by a pump and heated significantly before exiting.

#Gaseous ammonia is first pushed into the absorber, where it dissolves into the water.  It is somewhat pressurized by a pump and heated significantly before exiting.

#The ammonia is then moved under pressure to the condenser, where it is cooled.  Pressure is also reduced at this point, as the liquid shrinks due to the temperature decrease.

#The ammonia is then moved under pressure to the condenser, where it is cooled.  Pressure is also reduced at this point, as the liquid shrinks due to the temperature decrease.

#The refrigerant is next pushed through a throttling valve, which allows it to rapidly decompress.  This also cools the refrigerant significantly.

#The refrigerant is next pushed through a throttling valve, which allows it to rapidly decompress.  This also cools the refrigerant significantly.

#Lastly, the already chilled refrigerant enters the evaporator, where it takes heat from its surroundings and provides a cooling effect.

#Lastly, the already chilled refrigerant enters the evaporator, where it takes heat from its surroundings and provides a cooling effect.

#As a gas once again, the ammonia is again moved to the absorber, so that the process can repeat.<ref name="brighthubengineering apor-absorption-cycle">http://www.brighthubengineering.com/hvac/20355-methods-of-refrigeration-vapor-absorption-cycle</ref><ref>http://www.slideshare.net/IanLouiseCelestino/simple-vapor-absorption-refrigeration-system</ref><ref>http://mechanicalbuzz.com/simple-vapour-absorption-refrigeration-system-972.html</ref>

#As a gas once again, the ammonia is again moved to the absorber, so that the process can repeat.<ref name="brighthubengineering apor-absorption-cycle"/><ref>http://www.slideshare.net/IanLouiseCelestino/simple-vapor-absorption-refrigeration-system</ref><ref>http://mechanicalbuzz.com/simple-vapour-absorption-refrigeration-system-972.html</ref>

Although less efficient than modern options, vapor absorption still has its uses.  Electricity is required (by the pump), but much less is needed since it uses no compressor.  Rather, a large amount of the energy required is used as heat. This system is very common in mobile homes and recreational vehicles, where propane or natural gas is readily available, but battery power is limited.  It is also useful in some industries where excess heat can be put to good use.<ref name="brighthubengineering apor-absorption-cycle">http://www.brighthubengineering.com/hvac/20355-methods-of-refrigeration-vapor-absorption-cycle</ref>

Although less efficient than modern options, vapor absorption still has its uses.  Electricity is required (by the pump), but much less is needed since it uses no compressor.  Rather, a large amount of the energy required is used as heat. This system is very common in mobile homes and recreational vehicles, where propane or natural gas is readily available, but battery power is limited.  It is also useful in some industries where excess heat can be put to good use.<ref name="brighthubengineering apor-absorption-cycle"/>

===Gas cycle===

===Gas cycle===

===Vortex tube===

===Vortex tube===

[[File:Ranque-Hilsch Vortex Tube.png|thumbnail|300px|Ranque-Hilsch Vortex Tub diagram]]

[[File:Ranque-Hilsch Vortex Tube.png|thumbnail|300px|Ranque-Hilsch Vortex Tub diagram]]

Vortex tube cooling requires high pressure air to be forced through the vortex spin chamber.  It rotates first through the outer section of the tube (at about 1,000,000 RPM), then some escapes through a control valve at the far end.  The remaining air is sent back through the chamber, now in the inner portion.  This returning air releases some of it's energy in the form of heat, which goes into the outer, hotter stream.  The now-cold inner stream exits at the same end it entered, where it can be put to use while the hot air from the far end is ejected.<ref>http://www.exair.com/en-US/Primary%20Navigation/Products/Vortex%20Tubes%20and%20Spot%20Cooling/Vortex%20Tubes/Pages/How%20a%20Vortex%20Tube%20Works.aspx</ref><br />

Vortex tube cooling requires high pressure air to be forced through the vortex spin chamber.  It rotates first through the outer section of the tube (at about 1,000,000 RPM), then some escapes through a control valve at the far end.  The remaining air is sent back through the chamber, now in the inner portion.  This returning air releases some of its energy in the form of heat, which goes into the outer, hotter stream.  The now-cold inner stream exits at the same end it entered, where it can be put to use while the hot air from the far end is ejected.<ref>http://www.exair.com/en-US/Primary%20Navigation/Products/Vortex%20Tubes%20and%20Spot%20Cooling/Vortex%20Tubes/Pages/How%20a%20Vortex%20Tube%20Works.aspx</ref><br />

Vortex tube cooling has not proven an efficient cooling method as of yet, but could still be used, especially as an addition to another system.<ref>http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1536&context=iracc</ref>

Vortex tube cooling has not proven an efficient cooling method as of yet, but could still be used, especially as an addition to another system.<ref>http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1536&context=iracc</ref>