S.T.J INSTITUTE OF TECHNOLOGY

Department of Mechanical Engineering

Seminar on-

CRYOCAR

PUNEET M GAONKAR

By-

CONTENTS1. INTRODUCTION

2. LIQUID NITROGEN VEHICLE

3. MANUFACTURE OF LIQUID NITROGEN

4. LIQUID NITROGEN PROPULISION CYCLE

5. PARTS OF LNPC

6. PRINCIPLE OF OPERATION

7. EFFICIENCY

8. ADVANTAGES

9. TECHNICAL ISSUES

10. CONCLUSION

11. REFERENCES

INDRODUCTION

Use of Alternate Resources

PollutionHuman Greed

CRYOCAR

uses

Cryogenic fuel

like

Liquid Nitrogen

LIQUID NITROGEN VEHICLE

It is a vehicle which uses Cryogenic fluid(liquid nitrogen) as a

working fluid.

The propulsion systems in these vehicles were cryogenic heat

engines in which a cryogenic substance is used as a heat sink for

heat engine.

LIQUID NITROGEN VEHICLE….

The liquid nitrogen powered vehicles was independently developed by University of North Texas (UNT)

and University of Washington (UW).

The vehicle (car) was named as LN2000.

The main Scientist behind this discovery is Abraham Hertzberg.

MANUFACTURE OF LIQUID NITROGEN Atmospheric air is passed

through dust precipitator and pre-cooled.

It is then compressed inside large turbo pumps.

Air allowed to expand rapidly through a nozzle into an insulated chamber.

By running several cycles the temperature of the chamber becomes low enough. The air entering it starts to liquefy.

Liquid nitrogen is removed and is stored inside well-insulated Dewar flasks or Storage vessel.

Atmospheric

Air passes

Fractional

Distillation

Dust

Precipitator

Inter cooler

Nozzle

LN2

Insulated chamber

Expansion

Turbo

pumps

Dewar Flask

LIQUID NITROGEN PROPULISION CYCLE

The main parts of a liquid

nitrogen propulsion system are:

1. Cryogen Storage Vessel.

2. Pump.

3. Economizer.

4. Heat Exchanger

5. Expander Engine.

PARTS OF LNPC

Cryogen

Storage

Vessel

A pressurized tank to store liquid nitrogen.

Resistance to deceleration forces in the horizontal plane in the event of

traffic accident, Low boil-off rate , minimum size and mass and

reasonable cost.

Pump

The pump is used to pump the liquid nitrogen into the engine. The

pump which are used for this purpose have an operating pressure

ranging between 500 – 600 Psi. As the pump, pumps liquid instead

of gas, it is noticed that the efficiency is high.

Economizer

A Preheater, called an economizer, uses left over heat in the

engine’s exhaust to preheat the liquid nitrogen before it enters

the heat exchanger.

Improves efficiency.

PARTS OF LNPC…….

Heat

Exchanger

A primary heat exchanger that heats (using atmospheric heat)

LN2 to form N2 gas, then heats gas under pressure to near

atmospheric temperature

PARTS OF LNPC…….

ExpanderAn Expander to provide work to the drive shaft of the

vehicle.

Principle of operation

Cryogen Storage Vessel

Pump

Economizer

Heat Exchanger

Expander Engine

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 KPa.

The pressurized N2 gas drives the motor.

The only exhaust is nitrogen, which is major constituent of

our atmosphere.

Energy+N2(l)-->N2(g)

EFFICIENCY

The first LN2 car could travel 79 miles (127.58 km) on a full 24 gallon (90 liter)

tank of liquid nitrogen going 32 Kmph.

Its maximum speed was over 56 Kmph.

After further Researches, the Efficiency has improved as follows:

Power : 78KW or 104.5bhp @ 97Kmph

400 Liters (106 gallon) gives a mileage of 560Km and weighs 280Kg

Operating Cost is around 2.4cents per Km( Re 1 per Km)

Advantages

ZEV

Electric Car

Weight & Refilling

Range

Environment friendly

As Compare to Electric Cars:

Advantages …..

Fossil Fuels

Burning Fossil fuels in a Power

Plant

Very easy to Produce

Eco Friendly

As Compared to Fossil Fuels:

TECHNICAL ISSUES

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.

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.

CONCLUSION In a real sense, the more such vehicles are used, the cleaner the air will become

Time to recharge, infrastructure investment and environmental impact are among the

issues to consider , in addition to range and performance , when comparing the relative

merits of different ZEV technologies.

Manufacturing LN2 from ambient air inherently removes small quantities of

atmospheric pollutants and the installation of large-scale liquefaction equipment at

existing fossil-fuel power stations could make flue gas condensation processes

economical.

Extra research work is needed to utilize the most of the available energy

REFERENCES

[1] “LN2000”, University of Washington Research Team, Sept. 18, 2007

[2] “Liquid Nitrogen”, Wikipedia Online Encyclopedia.

[3] Proceeding of 18th International Cryogenic Engineering Conference (Edited by K.G

Narayankhedhar, Narosa Publishing House)

[4] AICTE-ISTE Short term Programme on contribution to technology development from

Space Research.

[5] “Cryogenic Chilling and Freezing”, BOC Gases.

[6] “Cryogenic Paint Removal”, Sig Attilio Bernasconi

[7] Processes and Materials of Manufacture by R.A. LINDBERG

-by Puneet Gaonkar…