This document summarizes a proposed vehicle called the Cryocar that is powered by liquid nitrogen. The Cryocar works similarly to a steam engine by pressurizing and vaporizing liquid nitrogen using ambient heat, which expands to drive the vehicle. It has zero emissions and refueling takes only a few minutes. However, issues around safety from nitrogen leaks and the energy required to liquefy nitrogen have prevented commercialization. The document outlines the components, working principle, advantages over electric vehicles, drawbacks, and potential solutions of the Cryocar concept.

1. CRYOCAR
 PRESENTED BY UNDER GUIDENCE OF
 KIRAN KUMAR PROF. RITESH MULGE
 USN-3AE10ME012

2. ABSTRACT
 Cryogens are effective thermal storage medium which
can be used for automotive propulsion, that boils at a
temperature below about 110k
 An automotive propulsion concept is present with
open rankine cycle which utilise liquid nitrogen as
work fluid.
 Pressurised liquid nitrogen(LN2) can be vapourised by
only heat input to engine which is supplied by ambient
heat exchanger , resulting in easy propulsion of
automobile.
 Refill of LN2 requires only few minutes .

3. CONTENTS
 INTRODUCTION
 THEORY BEHIND CRYOCAR
 WHAT IS CRYOCAR
 COMPONENTS OF CRYOCAR
 WORKING OF CRYOCAR
 ADVANTAGES AND DISADVANTAGES

4. INTRODUCTION
 Various factors that influence choice of car include
performance , fuel ,pollution etc.
 As price of fuels are increasing and availability is
decreasing we have to go for alternate choice.
 At this point of view we have “ CRYOCARS “ as an
alternate choice.

5. THEORY BEHIND CRYOCAR
 Research at the university of Washington are
developing a new Zero Emission automobile
propulsion concept that uses LN2 as fuel .
 Principle of operation is like that of steam engine ,
except there is no combustion involved.
 Instead LN2 is pressurised and then vapourised in a
heat exchanger by ambient temperature of
surrounding air.

6. WHAT IS CRYOCAR?
 It is a liquid nitrogen powered vehicle.
 Propulsion systems are cryogenic heat engines in
which a cryogenic substance is used as a heat sink.

7. Cryogenic Heat Engine
 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.

8. Liquid Nitrogen(LN2)
 Liquid Nitrogen is the 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.

9. LIQUEFACTION OF LN2
Atmospheric
Air passes
Dust
Precipitator
Fractional
Distillation
Inter cooler
Nozzle
LN2
Insulated
chamber
Expansion
Turbo
pumps
Dewar Flask

10. Main Components of the Engine:
 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.

12. Principle of Operation:
 LN2 at –320oF (-196oC) 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.

13. •The pressurised N2 gas drives the motor.
•The only exhaust is nitrogen, which is major constituent of our
atmosphere.
•Energy+N2(l)-->N2(g)
Hence, there is no pollution produced by running this car.

15. Advantages over electric cars:
 A liquid nitrogen car is much lighter and refilling its
tank takes only about 10-15 minutes.
 The exhaust produced by the car is environmental
friendly.
 A cryogenic car could have three times the range of an
electric car of the same weight and no battery disposal
concerns .

16. Drawbacks:
 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.
 If nitrogen car is kept in a poorly ventilated space and, if
there is a 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.

17. Probable Solutions:
 A tube within a tube design.
 N2 passes back and forth inside a set of three nested
tubes.
 By the time it reaches the outermost tubes, the N2 is
warm enough that the exterior wall of the tube
remains above the freezing point of water.
 Route the exhaust from the fossil fuel power plants
through cryogenic plants, so that the pollutants and
the greenhouse gases could be condensed for later
disposal

18. Efficiency:
 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.

19. Why not commercialized?
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.

20. Conclusion:
 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.

21. REFERENCE
[1] “LN2000”, University of Washington Research Team, Sept. 18, 2007
<http://www.aa.washington.edu/AERP/CRYOCAR/CryoCar.htm>."
[2] “Liquid Nitrogen”, Wikipedia Online Encyclopedia, Sept. 13, 2007
<http://en.wikipedia.org/wiki/Liquid nitrogen>.
[3] “Cryogenic Chilling and Freezing”, BOC Gases, Sept. 18, 2007 <http://www.boc-gases.
com/products and services/by process/cryogenic_chilling_and_freezing.asp>.
[4] “Cryogenic Paint Removal”, Sig Attilio Bernasconi, Sept. 18, 2007
<http://www.p2pays org/ref/10/09444.htm

22. THANK YOU