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CRYOCAR
Cryo - means cold
Genics - means science.
The branches of physics and engineering that involve the study of very low temperatures, how to produce them, and how materials behave at those temperatures.
It is a liquid nitrogen powered vehicle.
Propulsion systems are cryogenic heat engines in which a cryogenic substance is used as a heat sink.
It is a engine which uses very cold substances to produce useful energy.
There is always some heat input to the working fluid during the expansion process.
Cryoengine works on Rankin Cycle
Liquid Nitrogen is the cheapest, widely produced and most common cryogen.
It is mass produced in air liquefaction plants
The liquefaction process is very simple.
Normal, atmospheric air is passed through dust precipitator and pre-cooled.
A pressurized tank to store liquid nitrogen.
Pressurant bottles of N2 gas substitute for a pump. The gas pushes the liquid nitrogen out of the Dewar that serves as a fuel tank.
A primary heat exchanger that heats (using atmospheric heat) LN2 to form N2 gas, then heats gas under pressure to near atmospheric temperature.
An Expander to provide work to the drive shaft of the vehicle.
An economizer or a secondary heat exchanger, which preheats the liquid N2 coming out from the pressurized tank taking heat from the exhaust.
LN2 at –320 °F (-196 °C) is pressurized and then vaporized in a heat exchanger by ambient temperature of the surrounding air.
This heat exchanger is like the radiator of a car but instead of using air to cool water, it uses air to heat and boil liquid nitrogen.
Liquid N2 passing through the primary heat exchanger quickly reaches its boiling point.
The N2 expands to a gas with a pressure of 150 psi.
Much like electrical vehicles, liquid nitrogen vehicles would ultimately be powered through the electrical grid. Which makes it easier to focus on reducing pollution from one source, as opposed to the millions of vehicles on the road.
Transportation of the fuel would not be required due to drawing power off the electrical grid. This presents significant cost benefits. Pollution created during fuel transportation would be eliminated.
Lower maintenance costs
Conti……
Liquid nitrogen tanks can be disposed of or recycled with less pollution than batteries.
Liquid nitrogen vehicles are unconstrained by the degradation problems associated with current battery systems.
The tank may be able to be refilled more often and in less time than batteries can be recharged, with re-fueling rates comparable to liquid fuels.
The N2 passing through the tubes of the heat exchanger is so cold that the moisture in the surrounding air would condense on the outside of the tubes, obstructing the air flow.
Then there's the safety issue. Should a nitrogen car be kept in a poorly ventilated space and, if the Nitrogen leaks off, it could prove fatal.
Turning N2 gas into a liquid requires a lot of energy. So while cryogenic cars have zero emissions, they rely on energy produced at emission generating power plants.
The principal disadvantage is the inefficient use of primary energy. Energy is used to liquefy nitrogen, which in turn provides the energy to run the motor. Any conversion of energy results losses. For liquid nitrogen cars, electrical energy is lost during the liquefaction process of nitrogen.
Liquid nitrogen is not yet available in public refueling stations.
The LN2 car can travel 15 miles on a full (48 gallon) tank of liquid nitrogen going 20 MPH.
Its maximum speed is over 35 MPH.
Even though the technology is 10 to 12 years old, still it has not come to the market for two reasons.
Safety issues have not been sorted out as yet.
Lack of funds for research.
Technology has certain limitations such speed, leakage hazard, generating liquid nitrogen etc.
In a real sense, the more such vehicles are used, the cleaner the air will become.
In addition to the environmental impact of these vehicles, refueling using current technology can take only a few minutes, which is very similar to current gas refueling times.
Research paper on “Liquid Nitrogen as a Non-Polluting Vehicle Fuel” by Mitty c. Plummer, Carlos A. Ordonez and Richard F. Reidy, University of North Texas.