Prepared by: Berk Demirgok
Dept. of Electrical and Computer Engineering
Utah State University
3/15/2012
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References
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Overview
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Types of compressors
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Major applications
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Purchasing
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Fluid Mechanics: Fundamentals and
Applications By Yunus A. Çengel, John M.
Cimbala - McGraw-Hill College (2009)
Introduction to Fluid Mechanics [Book] by
Robert W. Fox, Philip J. Pritchard, Alan T.
McDonald
Mechanical measurements by Thomas G.
Beckwith, Roy D. Marangoni, John H. Lienhard
Wikipedia
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http://www.chem.queensu.ca/people/faculty
/mombourquette/firstyrchem/GasLaws/inde
x.htmhttp://www.electronicstutorials.ws/io/io_2.html
http://www.fscconline.com/%22Passing%20Gas%22article/passing_gas.htmlhttp://www.autonics.
com/products/products_2.php?big=01&mid=
01/06
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https://engineering.purdue.edu/~propulsi/pr
opulsion/jets/basics/comp.html
http://knowledgepublications.com/doe/doe_
mechanical_science_web_educational_textbook
_solar_hydrogen_fuel_cells.htm
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Compressors increases pressure on a fluid,
gasses with compressing gasses. With
increasing pressure, volume of gasses are
reduced by compressors. However, liquids are
incompressible and cannot be used as a fluid
for compressors.
Also, note that when compressors change the
pressure of a fluid, fluid’s temperature changes
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Moreover, pumps are like compressors. They
both work in the same principle. However,
pumps can only transport the fluid.
http://www.aardvarkclay.com/catalog_p
ages/compressors.html
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Compressibility helps us to measure volume
change of fluids as a reaction to change in
pressure.
𝑃 ∗ 𝑉 = 𝑛 ∗ 𝑅 ∗ 𝑇 is the relation between
volume, pressure, unity and temperature. This
equation is called ideal gas law and we can use
it as a compressibility factor equation.
Compressibility factor equation is
𝑃∗𝑉 =𝑍∗𝑅∗𝑇
𝑃∗𝑉 =𝑛∗𝑅∗𝑇
𝑃∗𝑉 =𝑍∗𝑅∗𝑇
P is the pressure and its unit is Pa in SI units.
V is the volume and its unit is m^3.
N is the amount of substance of a gas and its unit
is mol.
R is the universal gas constant, 0.08206
L*atm*mol^-1*K^-1.
T is the temperature and its unit is K.
Z is compression factor for gasses.
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For each type of fluid or gasses, they have their
own compression factors. Next slide shows z
factors for only air.
• http://www.chem.queensu.ca/people/
faculty/mombourquette/firstyrchem/G
asLaws/images/compressibility.gif
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Turbo Compressors
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Axial
Centrifugal
Displacement Compressors
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Reciprocating
Rotary
 Screw
http://www.refrigeratortroubleshoot.com
/refrigerating-compressors.html
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Centrifugal Compressors are also called
annular compressors.
It uses a rotating impeller rotating with really
high speed to apply force on refrigerant into a
diffuser. Diffuser section converts the velocity
energy into pressure energy.
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Advantages
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Easy to design and fabrication
It generally rises the pressure enough for efficient
combustion with only one step without any
problems.
Disadvantages
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Less fuel efficiency
Pressure ratio is generally lower causing creating
less thrust.
http://www.georgiapower.com/energy_k
nowhow/images/c00090.gif
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Working fluid goes through out parallel the
axis of rotation. However working fluid goes
vertical for centrifugal compressors.
Advantages
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It creates higher flow rate and pressure so that
increases thrust and fuel efficiency.
High peak efficiency.
They large mass flow volume.
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Disadvantages
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Axial compressors are hard to built and costs a lot
of money to manufacture.
They weigh much higher than centrifugal
compressors.
In order to start axial compressors, it requires high
starting power.
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Typical axial Compressor is shown below.
http://www.adl.gatech.edu/classes/prop
ulsion/prop12.html
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Reciprocating compressors that the volume of
fluid is reduced by a movement of a piston
inside cylinder.
Rotary compressors that the volume of fluid is
reduced by rotation of some parts without
reciprocating or piston movement.
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Reciprocating and rotary compressor
http://nuclearpowertraining.tpub.com/h1
018v2/img/h1018v2_86_1.jpg http://knowledgepublications.com/doe/i
mages/DOE_Mechanical_Science_Recipro
cating_Air_Compressor.gif
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Advantages
They are inexpensive.
 They have very wide-range horsepower options.
 Better mass flow rate.
 Better efficiency.
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Compressors are widely used in our world.
Some of the application areas are:
Medical use
Welding use
Aircrafts
Air conditioner
Pipeline transport
Rail transport
Automotive Industry
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Price range is very different for each type of
compressor. You can reduce your cost by
thinking buying used compressors.
There are some good online stores to buy
compressors.
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www.aircompressorsdirect.com
www.lowes.com
www.compressor.pronto.com
www.northerntool.com