CRYOCAR

PRESENTED BY UNDER GUIDENCE OF

KIRAN KUMAR PROF. RITESH MULGE

USN-3AE10ME012

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 .

CONTENTS INTRODUCTION

THEORY BEHIND CRYOCAR

WHAT IS CRYOCAR

COMPONENTS OF CRYOCAR

WORKING OF CRYOCAR

ADVANTAGES AND DISADVANTAGES

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.

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.

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.

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.

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.

LIQUEFACTION OF LN2

Atmospheric

Air passes

Fractional

Distillation

Dust

Precipitator

Inter cooler

Nozzle

LN

2

Insulated

chamber

Expansion

Turbo

pumps

Dewar Flask

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.

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.

•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.

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 .

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.

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

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.

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.

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.

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

THANK YOU