CHAMELI DEVI GROUP OF INSTITUTIONS

Department of mechanical engineering Seminar on-

CRYOCARAMAN

KAPOOR By-

Topic of interest-1) Introduction

2) What is liquid nitrogen vehicle?

3) Why nitrogen as a vehicle fuel?

4) Parts of a LNPC

5) Principle of operation

6) Liquid nitrogen propulsion cycle

7) Advantages over electric cars

8) Efficiency

9) Drawbacks

10)Why not commercialized?

11)Conclusion

INDRODUCTION

Use of alternate resource

sPollutionHuman

greed

CRYOCAR

uses

Cryogenic fuel

like

Liquid Nitrogen

What is liquid nitrogen vehicle? It is a vehicle which uses Cryogenic fluid(liquid nitrogen) as a working fluid.

Propulsion system is a cryogenic heat engine in which a cryogenic substance is used as a heat sink.

CRYOGENICSCryogenic can be defined as the branch of the physics that deals with the study of the production of very low temperature (below −150 °C, −238 °F or 123 K) and the behavior of materials at those temperatures.

Why nitrogen as a vehicle fuel?

High cost and limited availability of fossil fuels like petrol and diesel.

Due to high level of pollution associated with the combustion of fossil fuels the need of ZEV(Zero Emission Vehicle) has been generated. (presently the battery powered electric vehicle is the only commercially available ZEV but not successful due to high initial cost, slow recharge and limited range).

And the most important is the huge availability of Nitrogen gas(78% of air is nitrogen).

Note: According to Petroleum Conservation and Research Association petroleum production will be at its peak in 2012 and is likely to decrease after that.

Parts of a LNPC 1)

Cryogen storage vessel

A pressurized tank(24 gallon) to store liquid nitrogen.

Low boil-off rate , minimum size and mass and reasonable cost.

2)Pump

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

Operating pressure between 500-600psi

3)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…….

4)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.........

5)Expande

r

An Expander to provide work to the drive shaft of the vehicle.

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 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)

Hence, there is no pollution produced by running this car.

Liquid nitrogen propulsion cycleCryogen storage vessel

Pump

EconomizerHeat Exchanger

Expander Engine

EXHA

UST

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

ZEV

Efficiency- The LN2 car can travel 79 miles(127.58 km) on a full 24 gallon(90

liter) tank of liquid nitrogen going 20 MPH.

Its maximum speed is over 35 MPH.

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.

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.

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.

SAD

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.

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