MAGNETO HYDRODYNAMIC

GENERATORS

PRESENTED BY

NITHIN GOPAL

CONTENTS

1 . Introduction

2 . Brief Story

3 . Principles Behind

4 . Construction

5 . Working

6 . Classifications

6 . M.H.D Systems

7 . Merits and Demerits

8 . Applications

9 . Contents taken from…

INTRODUCTION Energy produced from the conventional methods is not sufficient for the daily use because of energy

crisis is on its maximum level.

So , more energy must be produced by non conventional methods of energy production.Magneto hydro dynamics is dynamics of electrically-conducting fluids and their interactions with magnetic field.

M.H.D generator is a new non conventional power generation system which has high efficiency and low pollution.

BRIEF STORY

o It was Michael Faraday who first discussed about M.H.D generators in 1832.

o First international conference on M.H.D power in1962.

o First M.H.D generator was found in 1965.

o At the beginning of 70s,interest in MHD declined because nuclear power was becoming more widely available.

o In 1975, UNESCO became persuaded the MHD might be the most efficient way to utilise world coal reserves .

o By 1994, Russia had developed and operated the coal-operated facility .

PRINCIPLES BEHIND

The main principles behind M.H.D generators are:

1.FARADEY’S LAW OF ELECTRO MAGNETIC INDUCTION.

2.‘LORENTZ FORCE LAW.

FARADAY’S LAW OF ELECTRO MAGNETIC INDUCTION

When a conductor is placed in a changing magnetic field , an E.M.F is induced in that conductor.

LORENTZ FORCE LAW

A charged particle moving through a magnetic field experiences a force that is at right angles to both the direction in which the particle is moving and the direction of the applied field.

F=Q .(v*B)

CONSTRUCTION

Linear MHD channel (front view):-

Linear MHD channel (side view):-

Wall assembly of the disc MHD channel:-

Components of disc MHD generator:-

Components of the ionized seed injection system:

WORKING

WORKING

Classifications

According to the construction, it can be classified into four:

1. Faraday generator

2. Hall generator

3. Diagonal generator

4. Disc generator

Faraday generator

Hall generator

Diagonal generator

Disc generator

M.H.D. POWER GENERATING SYSTEM

An M.H.D power generating system consists of the following parts:

1.Heater

2.M.H.D generator

3.Cooler

4.Compressor

Simple block diagram of a M.H.D system

CLASSIFICATIONS OF M.H.D SYSTEMS

M.H.D systems

Open cycle system

Closed cycle system

Seeded inert gas system

Liquid metal system

Open cycle system

In open cycle system ,oil or gasified coal may used as fuel.

The fuel is burnt in the combustor and the hot gases from the combustor is then mixed with a small amount of an ionized alkali metal (cesium or potassium) to increase the electrical conductivity of the gas.

OPEN CYCLE SYSTEM

Closed cycle system In this system , instead of

directly feeding the burnt gas is into the generator , a heat exchanger is used to transfer the heat from combustor to the generator.

According to the medium used to transfer the heat, this system is broadly classified into two.

1. Seeded inert gas system

2. Liquid metal system

Seeded inert gas system

This system uses inert gases as energy carriers from heat exchanger to the generator . Some ionized materials are seeded into the carrier as in the open cycle system.

Seeded inert gas system

Liquid metal system

Here the carrier is liquified metal . Usually Sodium is used as the working fluid .This directly induces the E.M.F into the generator . So no seeding is needed.

Liquid metal system

MERITS OF M.H.D GENERATORSHigh efficiency as compared to

steam power plants.

Large amount of power is generated.

No moving parts .

Closed cycle produces less pollutants.

It can be started instantaneously.

Much smaller sized plant can be used.

Direct conversion of heat into electricity is happened.

Solar energy also can be used for producing heat.

DEMERITS OF M.H.D GENERATORS

Since the generator works at very high temperature, the materials used for the construction must withstand high temperature.

Pollution cannot be neglected.

Less efficient than Hydro power generation.

Seed materials attack the insulation.

High capital cost.

APPLICATIONS

o They are used in large scale power production for industrial and domestic applications.

o Is used in space applications like power production in Rockets , Space ships etc.

CONTENTS TAKEN FROM…Non conventional energy sources-G .D . Rai

www.ehow.com

www.wikipeadia.com

www.electropedia.com

www.buzzle.com

Renewable sources of energy – M.Rrjalingam

THANK YOU