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CRYOGENIC CARS

WHAT ACTUALLY IS:

A cryogenic car is a car that works on the fuel at a very low temperature (cryogenic

temperature), less than -150oc or 123k.

WHY:

There are mainly two reasons behind it:

1. The need of automobiles is growing day by day. Statistics shows that the fuel used perday is increasing at a high rate every year mainly due to transportation. But the

amount of stored bio-fuel (e.g. coal, petroleum) is limited

2. All so called bio-fuel driven cars need combustion to get the energy. Carbon di oxide,carbon monoxide, sulphur di oxide, Oxides of nitrogen, PM are some of the bi-products

of the combustion. Some of these are greenhouse gasses adding a greater aspect to

global warming.

These are the reasons why we need alternative fuels. Cryogenic fuel is one of such alternative

fuels.

HISTORY:

1st idea introduced by Dennis Papin at the year of 1687 at the British Royal Council.

In 1926 Lee Barton Williams of Pittsburg USA presented his invention: an automobile which,

he claims runs on air. The motor starts on gasoline, but after it has reached a speed of ten

miles an hour the gasoline supply is shut off and the air starts to work. At the first test his

invention attained a speed of 62 miles an hour.

Grumman-Olson Kubvan was the first with a 15-hp, 5-cylinder air motor plus a preheater to

deal with the nitrogen in 1984.

In 1997, the University of North Texas (UNT) developed the CooLN2Car, which also ran off of

cryogenic liquid nitrogen using an isothermal expansion engine.

In 2000, the University of Washington created the LN2000, which was a converted mail delivery

van that ran on liquid nitrogen.

Energy density

Compressed air has relatively low energy density. Air at 30 MPa (4,500 psi) contains about 50

Wh of energy per liter. For comparison, a lead

acid battery contains 60-75 Wh/l. A lithium-ionbattery contains about 250-620 Wh/l. Gasoline contains about 9411 Wh per liter.[1]; however,

a typical gasoline engine with 18% efficiency can only recover the equivalent of 1694 Wh/l. The

energy density of a compressed air system can be more than doubled if the air is heated prior

to expansion.

In order to increase energy density, some systems may use gases that can be liquified or

solidified. "CO2 offers far greater compressibility than air when it transitions from gaseous to

supercritical form."

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1 Barrel= 42 US Gallons (roughly 159 liters)

MDI = Motor Development International

BMW has a production ready Mini vehicle powered by liquid hydrogen, called the BMW Mini

Hydrogen rolled out in 2001. In 1999, the BMW 750hl was introduced as the first liquid

hydrogen powered car. The BMW 750hl was powered by a 12-cylinder combustion engine withtwo independent fuel induction systems, which are electronically controlled to run off of either

gasoline or liquid hydrogen fuel tanks. The BMW 750hl also contains a solar-powered voltaic

array which generates electricity to split water into hydrogen and oxygen. The oxygen is

released into the atmosphere and the hydrogen is liquefied and stored at extremely low

temperatures (-253 C). During the internal combustion phase, the hydrogen combines with

oxygen to power the vehicle and water is released as steam.

Another exciting development in liquid hydrogen fuel technology is the world's first Unmanned

Aerial Vehicle (UAV) powered by cryogenic liquid hydrogen has completed flight tests.

California-based AeroVironment developed the UAV for purposes such as hurricane tracking

from heights such as 65,000 - 98,000 feet above sea level. The unmanned plane can stay in the

air for approximately 24-hours before it needs refueling.

To ensure smooth running and to optimize energy efficiency, our engines use a simple electromagnetic distribution

system which controls the flow of air into the engine.This system runs on very little energy and alters neither the

valve phase nor its rise.

Advantages

The principal advantages of an air powered vehicle are:

Refueling can be done at home using an air compressor [4] or at service stations. The energy required for

compressing air is produced at large centralized plants, making it less costly and more effective to manage carbon

emissions than from individual vehicles.

Compressed air engines reduce the cost of vehicle production, because there is no need to build a cooling system,

spark plugs, starter motor, or mufflers.[5]

The rate of self-discharge is very low opposed to batteries that deplete their charge slowly over time. Therefore,

the vehicle may be left unused for longer periods of time than electric cars.

Expansion of the compressed air lowers its temperature; this may be exploited for use as air conditioning.

Reduction or elimination of hazardous chemicals such as gasoline or battery acids/metals

Some mechanical configurations may allow energy recovery during braking by compressing and storing air.

Recent findings from Southwest Research Institute indicate that air-hybrids would allow for up to 50 percent

better fuel economy and an 80 percent reduction in emitted toxins compared to conventional engines [citation

needed]. Swedens Lund University also reports that buses could see an improvement in fuel efficiency of up to 60

percent using an air-hybrid system[6] But this only refers to hybrid air concepts (due to recuperation of energy

during braking), not compressed air-only vehicles.

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Disadvantages

The principal disadvantage is the indirect use of energy. Energy is used to compress air, which - in turn - provides

the energy to run the motor. Any conversion of energy between forms results in loss. For conventional combustion

motor cars, the energy is lost when chemical energy in fossil fuels is converted to heat energy, most of which goes

to waste. For compressed-air cars, energy is lost when chemical energy is converted to electrical energy, and then

when electrical energy is converted to compressed air.

When air expands in the engine it cools dramatically (Charles's law) and must be heated to ambient temperature

using a heat exchanger. The heating is necessary in order to obtain a significant fraction of the theoretical energy

output. The heat exchanger can be problematic: while it performs a similar task to an intercooler for an internal

combustion engine, the temperature difference between the incoming air and the working gas is smaller. In

heating the stored air, the device gets very cold and may ice up in cool, moist climates.

Conversely, when air is compressed to fill the tank it heats up. If the stored air is not cooled as the tank is filled,

then when the air cools off later, its pressure decreases and available energy decreases. The tank may require an

internal heat-exchanger in order to cool the air quickly and efficiently while charging, since without this it may

either take a long time to f ill the tank, or less energy is stored.

Refueling the compressed air container using a home or low-end conventional air compressor may take as long as

4 hours, though specialized equipment at service stations may fill the tanks in only 3 minutes.[4] To store 14.3 kWh

@300 bar in 300 liter reservoirs (90 m3 of air @ 1 bar), requires about 30 kWh of compressor energy (with a single-

stage adiabatic compressor), or approx. 21 kWh with an industrial standard multistage unit. That means a

compressor power of 360 kW is needed to fill the reservoirs in 5 minutes from a single stage unit, or 250 kW for a

multistage one.[7][citation needed] However, intercooling and isothermal compression is far more efficient and

more practical than adiabatic compression.

The overall efficiency of a vehicle using compressed air energy storage, using the above refueling figures, is around

50-70%. For comparison, well to wheel efficiency of a conventional internal-combustion drivetrain is about 14%,[8]

Early tests have demonstrated the limited storage capacity of the tanks; the only published test of a vehicle

running on compressed air alone was limited to a range of 7.22 km.[9]

A 2005 study demonstrated that cars running on lithium-ion batteries out-perform both compressed air and fuel

cell vehicles more than threefold at the same speeds.[10] MDI claimed in 2007 that an air car will be able to travel

140 km in urban driving, and have a range of 80 km with a top speed of 110 km/h (68 mph) on highways,[11] when

operating on compressed air alone, but in as late as mid 2011, MDI has still not produced any proof to that effect.

A 2009 University of Berkeley Research Letter found that "Even under highly optimistic assumptions the

compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas

emissions than a conventional gas-powered car with a coal intensive power mix." However, they also suggested, "apneumaticcombustion hybrid is technologically feasible, inexpensive and could eventually compete with hybrid

electric vehicles."[12]