Download pdf - mhd boiler

7/29/2019 mhd boiler

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Contents

1. Introduction2. Need of MHDs3. Principle Of MHD Power Generation4. Types of MHD SYSTEM5. Open Cycle MHD System6. Closed Cycle MHD System7. Diffrence between Open Cycle and

Closed Cycle MHD System8. Advantages OF MHD System9. Disadvantages of MHD System10. Applications

11. Conclusion


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Introduction

Magneto HydroDynamic (MHD) system is a non-conventional source of energy which is based upon

Faradays Law of Electromagnetic Induction, which

states that energy is generated due to the movement of

an electric conductor inside a magnetic field.


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Concept given by Michael Faraday in

1832 for the first time.

MHD System widely used in advancedcountries.

Under construction in INDIA.


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Need of MHDs

At present a plenty of energy is needed to

sustain industrial and agricultural production,

and the existing conventional energy sources

like coal, oil, uranium etc are not adequate to

meet the ever increasing energy demands.

Consequently, efforts have been made for

harnessing energy from several non-conventional energy sources like Magneto

Hydro Dynamics(MHD) System.


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Principle Of MHD Power

Generation: When an

electric conductor moves across a magnetic field, an emf isinduced in it, which produces an electric current .


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Lorentz Force on the

charged particle (vector),

F = q(v B)where,

v = velocity of the particle(vector)

q= charge of the particle

(scalar) B = magnetic field (vector)


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Comparison between a Turbo

generator and a MHD generator


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Types of

MHD SYSTEM

(1)Open cycle System

(2)Closed cycle System

(i)Seeded inert gas systems

(ii) Liquid metal systems


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OPEN CYCLE MHD SYSTEM


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HYBRID MHD STEAM PART

OPEN CYCLE


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CLOSED CYCLE MHD

SYSTEM

DIFFERENCE BETWEEN OPEN


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DIFFERENCE BETWEEN OPEN

CYCLE AND CLOSED CYCLE

SYSTEMOpen Cycle System

Working fluid after generating

electrical energy is discharged

to the atmosphere through astack .

Operation of MHD generator is

done directly on combustion

products .

Temperature requirement :2300C to 2700C.

More developed.

Closed Cycle System Working fluid is recycled to the

heat sources and thus is used

again.

Helium or argon(with cesium

seeding) is used as the working

fluid.

Temperature requirement : about530C.

Less developed.


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NEED FOR FURTHER

RESEARCH

The MHD channel operates on extreme conditions of

temperature, magnetic and electric fields .

So, numerous technological advancements are needed

prior to commercialization of MHD systems .

Search is on for better insulator and electrode

materials which can with stand the electrical, thermal,mechanical and thermo-chemical stresses and

corrosion.


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ADVANTAGES OF

MHD SYSTEM Conversion efficiency of about 50% .

Less fuel consumption. Large amount of pollution free power generated .

Ability to reach full power level as soon as started.

Plant size is considerably smaller thanconventional fossil fuel plants .

Less overall generation cost.

No moving parts, so more reliable .


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DISADVANTAGES OF

MHD SYSTEM

Suffers from reverse flow (short circuits) ofelectrons through the conducting fluids around theends of the magnetic field.

Needs very large magnets and this is a majorexpense.

High friction and heat transfer losses.

High operating temperature.

Coal used as fuel poses problem of molten ashwhich may short circuit the electrodes. Hence, oilor natural gas are much better fuels for MHDs.Restriction on use of fuel makes the operationmore expensive.


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APPLICATIONS

Power generation in space craft.

Hypersonic wind tunnel experiments.

Defense application.


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CONCLUSION

The MHD power generation is in advanced stage today

and closer to commercial utilization. Significant progress

has been made in development of all critical components

and sub system technologies. Coal burning MHDcombined steam power plant promises significant

economic and environmental advantages compared to

other coal burning power generation technologies. It will

not be long before the technological problem of MHD

systems will be overcame and MHD system would

transform itself from non- conventional to conventional

energy sources.


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THANK YOU !!