09-04-2014, 04:58 PM
Study and Fabrication of Compressed Air Engine
Fabrication of Compressed .pdf (Size: 297.4 KB / Downloads: 102)
ABSTRACT
As the world is hard pressed with the energy and fuel crises, compounded by pollution of all kinds, any
technologies that bring out the solutions to this problem is considered as a bounty. In one of such new
technologies, is the development of a new engine called as compressed air engine which does not require any of
the known fuels like diesel, petrol, CNG, LPG, hydrogen etc. this works using only compressed air. This replaces
all types of to-date known fuels and also permanently solves the problems of pollution as its exhaust is clean and
cool measured practically as low as 5oC. A proto type, a horizontal, single cylinder low speed engine was
modified to run on compressed air. Since this engine runs only on high pressure compressed air, the exhaust of
which is undoubtedly only air, making it a zero pollution engine. No heat is generated because there is no
combustion of fuel, hence this engine needs no cooling system and it result in reduced cost, weight, volume and
vibration. Early cost analysis shows that it's very cost effective and the operational cost is ten times less than that
of petrol or diesel. Experimental analysis were carried out on this modified engine to find out its performance
characteristics like brake power, mechanical efficiency, overall efficiency, air to Air ratio, volumetric efficiency,
cost analysis etc. Though the efficiencies were low as the frictional forces were high for the proto designed
engine, however the concept can be applied on a professionally designed engine to improve its performance.
INTRODUCTION
OSSIL fuels (i.e., petroleum, diesel, natural gas
and coal) which meet most of the world's energy
demand today are being depleted rapidly. Also, their
combustion products are causing global problems,
such as the green house effect, ozone layer depletion
acid rains and pollution which are posing great danger
for environment and eventually for the total life on
planet. These factors are leading automobile
manufactures to develop cars fueled by alternatives
energies. Hybrid cars, Fuel cell powered cars,
Hydrogen fueled cars will be soon in the market as a
result of it. One possible alternative is the air powered
car. Air, which is abundantly available and is free from
pollution, can be compressed to higher pressure at a
very low cost, is one of the prime option since
atmospheric pollution can be permanently eradicated.
Whereas so far all the attempts made to eliminate the
pollution has however to reduce it.
Behavior of compressed air
Compressed air is clean, safe, simple and efficient.
There are no dangerous exhaust fumes of or other
harmful by products when compressed air is used as
a utility. It is a non-combustible, non-polluting utility.
When air at atmospheric pressure is mechanically
compressed by a compressor, the transformation
of air at 1 bar (atmospheric pressure) into air at higher
pressure (up to 414 bar) is determined by the laws
of thermodynamics. They state that an increase
in pressure equals a rise in heat and compressing air
creates a proportional increase in heat. Boyle's
law explains that if a volume of a gas (air) halves
during compression, then the pressure is doubled.
Charles' law states that the volume of a gas changes
in direct proportion to the temperature[2].
DESCRIPTION OF AIR ENGINE
A compressed-air vehicle is powered by an air
engine, using compressed air, which is stored in a tank.
Instead of mixing fuel with air and burning it in the
engine to drive pistons with hot expanding gases,
compressed air vehicles (CAV) use the expansion of
compressed air to drive their pistons. One
manufacturer claims to have designed an engine that
is 90 percent efficient[9].
Compressed air propulsion may also be
incorporated in hybrid systems, e.g., battery electric
propulsion and fuel tanks to recharge the batteries.
This kind of system is called hybrid-pneumatic electric
propulsion. Additionally, regenerative braking can also
be used in conjunction with this system.
CONCLUSION
This is a revolutionary engine design which is eco
friendly, pollution free, but also very economical. This
redresses both the problems of fuel crises and
pollution. However excessive research is needed to
completely prove the technology for both its
commercial and technical viability.
It can be seen that the indicated power is increasing
for increase of load. As load is increased, the speed
falls down, to maintain it constant injection pressure
has to be increased. As the injection pressure has to
be increased, the indicated mean effective pressure
gets increased; hence the indicated power is increased
upon the application of the load. Though the applied
load was small, however, the developed power was
in proportion to the applied load. As load was applied
the speed was reduced, to maintain it constant, the
inlet air pressure has to be increased. As shown
injection pressure is increased. In the present case
the speed was maintained constant as 600 rpm. As
the output speed was less the brake power was
significantly lower. The mechanical efficiency is
increasing with the increase of output power. At lower
output it was very low.