A

Seminar Report
On
MAGNETIC HYDRO-DYNAMIC
POWER GENERATION
Submitted in partial fulfillment of the requirement
For the award of the
Degree of
Bachelor of Technology
In
Mechanical Engineering

Submitted By: Under the supervision of:

Harsh Jain Dr. Om Shankar Prajapati

(17/148) Associate Professor
(VIII Semester) Dept. of Mechanical Engineering
UTD, RTU Kota

Department of Mechanical Engineering

RAJASTHAN TECHNICAL UNIVERSITY, KOTA
Jun 2021
1
 CERTIFICATE
This is to certify that Mr. Harsh Jain, student of B.Tech (Mechanical Engineering)
VIIIth Semester has submitted his seminar entitled “Magnetic Hydro-dynamic”under
my guidance.

Dr. Om Shankar Prajapati

Associate Professor

i
 ACKNOWLEDGEMENT
First of all, I want to show my deepest gratitude to my guide Dr. Om Shankar Prajapati for his
constant support and guidance throughout the project period. The result presented in the report
are due to numerous useful discussions and suggestions given by him. Things became smoother
in progressing ahead with the project due to his supervision and dedication. His in-depth
knowledge and experience in this field along with enthusiastic spirit has been a constant source
of inspiration for me to understand fundamentals with clear ideas on the physics of the problem.
The work in the project would not have reached this level without his supervision

Harsh Jain
17/148

ii
 ABSTRACT
The Magneto hydrodynamic (MHD) power generation process is basically based on the physics
background of space plasma. The basic principle is the Faradays Law of electromagnetic
induction. In this device plasma (Ionized gas) is the working fluid similar to the mechanism that
happening in the magnetosphere of our earth’s atmosphere. Except here the process is controlled
and we increase the fluid density and pressure to get maximum efficiency in the generating
power. Most problems come from the low conductivity feature in the gas at high temperature.
High temperature gaseous conductor at high velocity is passed through a powerful magnetic field
and a current is generated and extracted by placing electrodes at suitable position in the gas
stream, and hence the thermal energy of gas is directly converted in to electrical energy. In this
paper the process involved in MHD power generation will be discussed in detail along with the
simplified analysis of MDH system and recent developments in magneto hydrodynamics and
their related issues.

iii
 LIST OF FIGURES

Figure 1: Basics of MHD .............................................................................................................................. 6

Figure 2: Direct energy Conversation stages ................................................................................................ 7
Figure 3: MHD Generator ............................................................................................................................. 9
Figure 4: Working Principle of MHD Power generation .............................................................................. 10
Figure 5: Different component of MHD ...................................................................................................... 13
Figure 6: Schematic diagram of faraday MHD generator ............................................................................. 15
Figure 7: Schematic diagram of Hall Effect MHD generator ....................................................................... 15
Figure 8: A disc type MHD System .............................................................................................................. 16
Figure 9: An open cycle coal fired MHD system. ........................................................................................ 18
Figure 10: A closed cycle MHD System ....................................................................................................... 19
Figure 11: Coal fired MHD topping unit with steam turbine........................................................................ 20
Figure 12: A typical closed cycle scheme for Nuclear source ...................................................................... 21
Figure 13: Schematic of two-phase cycle generator system ......................................................................... 22

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 TABLE OF CONTENTS
CERTIFICATE ............................................................................................................................................ i
ACKNOWLEDGEMENT .......................................................................................................................... ii
ABSTRACT ................................................................................................................................................ iii
LIST OF FIGURES ................................................................................................................................... iv
TABLE OF CONTENTS............................................................................................................................ v
INTRODUCTION....................................................................................................................................... 6
1.1 Literature Review ............................................................................................................................. 7
1.2 History................................................................................................................................................ 8
1.3 Working Principle............................................................................................................................. 9
1.4 MHD Generation Component ..................................................................................................... 11
1.4.1 MHD Fluid Channel ............................................................................................................... 11
1.4.2 Magnetic Field ......................................................................................................................... 11
1.4.3 Fluid Conductor ...................................................................................................................... 12
1.4.4 MHD Generation Electrodes.................................................................................................. 12
TYPES OF MHD GENERATION ......................................................................................................... 14
2.1 Faraday MHD Generation ........................................................................................................... 14
2.2 Hall MHD Generation .................................................................................................................. 15
2.3 Disc MHD Generation .................................................................................................................. 16
2.4 Liquid Metal MHD........................................................................................................................ 17
2.5 Open and Closed Cycle MHD ...................................................................................................... 17
ALLIANCE ................................................................................................................................................ 18
3.1 Working System of MHD with other Thermal Power Plant ...................................................... 18
3.2 Alliance of MHD with Conventional Thermal System ............................................................... 19
3.3 Alliance of MHD with Gas-steam plant ...................................................................................... 20
3.4 Alliance of MHD with nuclear plant ............................................................................................. 21
RESULTS AND DISCUSSION ............................................................................................................... 22
4.1 Possible development of MHD ....................................................................................................... 22
4.2 Advantages and Disadvantages ..................................................................................................... 23
CONCLUSION ......................................................................................................................................... 25
REFERENCES .......................................................................................................................................... 26

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CHAPTER 1
INTRODUCTION

The whole world is already familiar with the conventional power generating resources like
hydra, thermal and nuclear resources etc. In all the conventional thermal and nuclear resources
etc. In all the conventional systems the potential or thermal energy is first converted into
mechanical energy and then this mechanical energy is converted into electrical energy. The
conversion of potential energy into mechanical energy is significantly. This requires huge capital
cost as well as maintenance cost. All across the world researches are trying to convert thermal
energy directly into electrical energy by eradicating the mechanical process involved in energy
conversions which have significant energy losses. Research is now focusing its efforts on
conversion process that do not involve mechanical energy conversion step. In the absence of
moving mechanical part may allow in achieving the operating temperature much higher than the
typical conventional processes to attain effective power generating systems. These processes are
known as direct conversion systems in which primary or secondary energy is directly converted
into electrical energy without passing through the stage of mechanical energy.

Figure 1: Basics of MHD

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 Figure 2: Direct energy Conversation Stages

1.1 Literature Review

With the increase industry and agricultural activities, Power demand is also highly increased.
This means an additional capacity of power is required next 10 year. The answer to this is in
non-convectional energy. The MHD power generation is in advance advanced stage today and
closer to commercial utilization significant progress has been made in development of all
critical component and sub system technologies coal burning MHD combined steam power
plant promise significant economic and environmental advantages compared to other coal
burning power generate technologies. Also, in order to reduce CO2 emission, use nuclear power
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with high efficiency. We have to construct nuclear powered energy re-circulating type system.
Also idea of CO2 recovery type power generation system must be developed. Energy
recalculating type Nuclear/MHD power system was proposed to achieve high efficiency using
high operating temperature and eliminating bottoming cycle. For reduction of CO2 emission,
CO2 recovery type generator system was proposed, which has special features of using coal
synthesized gas burning with pure oxygen and heat recovery systems. In the MHD generator the
advantage of having no moving parts allows to work at higher temperatures than a conventional
energy conversion. It is possible to work with temperature around 3000K and a these
temperature the maximum theoretical efficiency would be near 90%.

1.2 History
In 1893, Michael Faraday was the first person who gives the idea of energy conversion in MHD.
Almost for the half of century no work was done on this concept. Later on in 1938, Westing
house research laboratory (USA) took the first step in utilizing the concept for developing a
MHD generator. "Process for the Conversion of Energy" was the initial patent on MHD by given
by B. Karlovitz, in 1940. Further research in 1960s was done by R. Rosa which established the
practicality of MHD with fossil-fuel systems. The International Conference on MHD Power was
held in Newcastle upon Tyne, UK by Dr. Brian C in 1962. After words in early 1970’s the
MHD-steam power plant U- 25 having a capacity of 75MW of which 25 MW is generated
through MHD was implemented. In 1975, the pilot plant was Lorentz installed in Tiruchirapalli
by BARC. The Japanese program in the late 1980s concentrated on closed-cycle MHD. The
belief was that it would have higher forced between the plates with a kinetic energy and pressure
differential sufficient to overcome the magnetic induction force Find. The end view drawing
illustrates the construction of the flow channel. An ionized gas is employed as the conducting
fluid. Ionization is produced either by thermal means i.e. by an elevated temperature or by
seeding with substance.

Over more than a ten-year span, engineers in former Yugoslavian Institute of Thermal and
Nuclear Technology (ITEN), Energoinvest Co., Sarajevo, had built the first experimental
Magneto-Hydrodynamic facility power generator in 1989. It was here it was first patented.

World War II interrupted development. In 1962, the First International Conference on MHD
Power was held in Newcastle upon Tyne, UK by Dr. Brian C. Lindley of the International

8
Research and Development Company Ltd. The group set up a steering committee to set up
further conferences and disseminate ideas. In 1964, the group set up a second conference in
Paris, France, in consultation with the European Nuclear Energy Agency.

Figure 3: MHD generator

1.3 Working Principle

The MHD generator generates electric energy by converting the kinetic energy directly into
electricity. The major constructional difference of an MHD generator from a conventional
electric generator is that the MHD generator uses the ionized fluids (gas or liquid or plasma) as
the electrical conductors. In a MHD generator, an ionized fluid is forced to move at a particular
velocity through a powerful magnetic field, an electromotive force (e.m.f.) is generated, which
can be suitably utilized to harvest the electric energy by placing two electrodes across fluid
stream (Fig. 1). The direction of the generated emf could be found by applying the Fleming’s
right hand rule. If the fluid moves along a direction perpendicular to the magnetic field, the
e.m.f. will be found to be developed perpendicular to the direction of fluid motion and that of the
magnetic field.

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 Figure 4: Working Principle of MHD Power Generation [4]

According to the principle of Faraday’s electromagnetic induction the amplitude of the generated
e.m.f. will be proportional to the fluid velocity and to the magnitude of the magnetic flux density.
In a MHD Generator, if the velocity of the fluid and the magnetic field density are denoted by V
and B respectively, the e.m.f. induced (E) across the MHD conductor is given by:

E=V×B (1)

Therefore, the induced current density (J) will be given by,

J=σ (2)

Where, σ = electric conductivity and Eind is the electric field intensity.

The retarding force on the conductor is the Lorentz force which will be represented by

F=J×B (3)

In a practical MHD system as shown below (Fig. 2) the fuel is used to generate heat to make the

10
gas ionized. The combustion chamber takes the fuel and air to produce the ionized gas or plasma.
The gas-plasma is passed through a nozzle to decrease the gas-pressure to increases the speed of
gas. As the gas speed is increased the power output is increased as described by the Eq. 1. The
gas exhausted from the MHD chamber is passed through a heat exchanger which takes the air as
an input and feed the air to the compressor after raising its temperature. Compressor takes the hot
air from the heat exchanger and supplies it to the combustion chamber for producing plasma.

1.4 MHD Generation Components

1.4.1 MHD Fluid Channel

The fluid flow in a MHD generator is guided and confined within a pipe or duct made up of
insulating materials. The shape or geometry of the duct may be different such as duct with
rectangular cross section or circular cross section. Also the inlet diameter is smaller compared to
the outlet diameter to reduce the pressure for increasing the speed of the flow to generate higher
amount of electricity. The performance of the MHD generator depends on the geometry of the
fluid flow, MHD duct and other components.

1.4.2 Magnetic Field

The voltage generation depends on the properties of the magnetic field [17] used in the MHD
system. The density of the magnetic field of a MHD generating system should be very high which
can be obtained ideally by a superconducting magnet [18]. A superconducting magnet is an
electromagnet which is developed with the current carrying conductor/coil made up of
superconducting wire. The superconducting wires can be considered as special electrical
conductors which are developed from superconducting materials. Superconducting materials are
the materials which exhibit no electrical resistance at their superconducting state and hence they
can conduct a considerably large amount of electric currents than conventional electrical
conductors. Therefor the superconducting magnets can be supplied with a large amount of
electrical current producing a huge amount of magnetic fields which can be very useful in many
applications where a large magnetic field is required such as MHD generating system, magnetic
resonance imaging system (MRI) etc.

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1.4.3 Fluid Conductor
The conducting medium in MHD generation is produced either by heating a gas to its plasma state
or to add the salts of alkali metals which are other easily ionizable substances and hence they can
enhance the conductivity. The MHD power generation can be performed either using gas-plasma
or the liquid metal flow or else. The Plasma MHD is a MHD generator when the conducting fluid
used in it is plasma. Plasma [20], which is often called “the fourth state of matter”, is an ionized
gas comprising of electrons (negatively charged particles and the ions. Therefore, the plasma is
superheated gaseous matter in which all or most of the electrons are found freely moving as the
electrodes are ripped away from the atoms by applying extra energy to the atoms making them
ions and making the gas ionized.
As a conducting fluid flow through a magnetic field can generate electric voltage, in plasma MHD
the plasma is passed through a channel kept in a magnetic field and the motion of the conducting
plasma through this magnetic field induces a voltage across the plasma. The direction of the emf
will be perpendicular to the direction of the plasma flow as well as the direction of the magnetic
field. Utilizing thermal ionization process gas-plasma is produced for the MHD generators.
In thermal ionization process the temperature of the gas is raised up to the point at which the
electrons are ripped away from the atoms by applying extra energy and can move freely along
with the ionized atoms (ionised after losing the electrodes) and hence the gas becomes electrically
conductive and makes the gas-plasma. Sometimes some seeding materials are mixed with the gas
to bring down the temperature at which the gas becomes ionized as a considerable high
temperature is required to convert the gas to gas-plasma applying the heat energy only. If some
chemical agents (like alkali metal, salts etc.) are mixed with the chemicals helps the gas to get
ionized easily even at the lower temperatures.

1.4.4 MHD Generator Electrodes

The MHD electrodes are used to collect the electricity generated in the MHD system. Generally
electrodes are metal components in MHD systems though the other materials are also possible to
be used. The geometry and position of the electrodes in MHD systems are very crucial as the
MHD performance depends on the electrode geometry and positions. MHD generators are
developed with multi-electrode configuration also.

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Figure 5: Different component of MHD

13
CHAPTER 2

Types of MHD Generation

A system with MHD generator has high potential of an ultimate efficiency i.e. 60 to 65% which
is much improved than the efficiency of conventional thermal power station i.e. 30 to 35%.
Output power of MHD generator for each cubic meter channel volume is directly proportional to
square of gas velocity and gas conductivity and square of the strength of the magnetic field
through which the gas flows. Moreover, for its competitive good performance the electrical
conductivity of the plasma (ionized gas) must be above the temperature range of 2000K. Usually
a number of issues like generator efficiency, economics, toxic products etc. are occurred during
the working of MHD generator .MHD generator is classified in three different designs which are
mentioned below:

● Faraday Generator

● Hall Generator

● Disk Generator

2.1 Faraday Generation

A Faraday generator is developed with a pipe or tube material kept under a magnetic field
created either by a permanent magnet or by an electromagnet (Fig. 3). The pipe should be
developed with an insulating material which will allow an electrically conducting fluid to flow
through it. Under a strong magnetic field (perpendicular to the pipe) as soon as a conductive
fluid flows through the pipe, an e.m.f. is induced across the conductor which will be
perpendicular to both the magnetic field and the fluid stream. The emf can be utilized to extract
the electrical power by placing two electrodes across the fluid flow (along the direction of
e.m.f.). In the Faraday generator, the magnitude of the electrical power available at the generator
output is found to be not only proportional to the cross sectional area of the tube and but also to
the speed of the conductor (conductive fluid flow).

The major drawback of the Faraday generating system is that there may be short circuit path
through the electrodes on the sides of the pipe used. Moreover, the design is also suffer from the
limitations imposed the density of the fluid as well as the type of magnetic field used. Due to the
14
flow of the fluid the temperature and the velocity of the fluid are reduced. The system also
suffers from the problem created by the Hall-effect current which makes the Faraday generator
very inefficient. A large Faraday generator needs an extremely powerful magnetic field which
can be developed with superconducting magnets.

Figure 6: Schematic Diagram of a Faraday MHD generation

2.2 Hall MHD generation

In Faraday MHD generation, the large amount of current produced at the generator output
interacts with the magnetic field present in the system and hence results in the displacement of
charge particle towards the perpendicular direction of the fluid flow path which is known as the
Hall Effect [31-32]. As a result, a transverse current is produced perpendicular to the fluid flow
direction and the total current produced is found as the vector sum of the components of traverse
current components and axial current component. To overcome this problem and to reduce the
energy loss and to improve efficiency, other MHD configurations are developed which such as
the Hall MHD generator. In Hall MHD generator, each of the rectangular electrodes are split into
an array of segments and placed side by side on both the side of the fluid channel. To harvest the
electrical power at a higher voltage with a lower current amplitude, all the electrode segments of
same side of the channel are kept insulated.

Figure 7: Schematic Diagram of a hall effect MHD generation

15
The Hall generator is developed with the arrays of segmented short electrodes which are used in
place of single rectangular electrodes. The electrical power is collected from the first and last
electrodes and among all other intermediate electrode one electrode is shorted to the electrode
placed just opposite to that electrode placed on the other side of the fluid channel. As a result, the
losses of the Hall generator are found less compared to a Faraday generator. The induced voltage is
also obtained with a higher value because there is less shorting of the final induced current.
However, this design has problems because the generator's efficiency very sensitive to its load.

2.3 Disk Generation

The Hall Effect Disc Type MHD generator is developed with a disc type MHD chamber through
which the fluid can flow through between the centres of the disc exhausted through the ducts
placed around the edge of the discs. The magnetic field is produced by a two circular Helmholtz
coils above and below the disk. Two pairs of the ring electrodes (RE) are placed inside the disc
chamber to provide the paths to flow the Hall Effect current. One pair of ring electrodes with
smaller diameter (Re) is placed near the inlet duct at the disc Centre where as the other pair of
ring electrodes with larger diameter (RE) is placed at near the periphery of the disc. In this MHD
system, the Faraday currents are conducted through the periphery of the disk and the Hall Effect
currents are passed between the Re and the RE. The wide flat gas flow, parallel magnetic field
lines and increased magnetic field strength enhance the efficiency of the system.

Figure 8: A disk type MHD system

16
2.4 Liquid Metal MHD
Liquid metal MHD generators use the liquid metals as their electrically conducting fluids and
hence they are known as the Liquid metal MHD generators. As the electrical conductivity of the
metals are extremely high and as the liquid metals can be converted into a fluid flow, the liquid
metals can suitably be used as the conducting fluids in MHD generating systems. The Liquid
metal MHD generators can be operated at lower temperature as the high temperature is not
required for the producing of plasma. The liquid metals are first combined with a driving gas or
are accelerated by a thermodynamic pump and then separated from the driving gas before it
passes through the MHD channel.

2.5 Open and Closed Cycle

MHD Depending on the flow paths of the conducting fluids the MHD systems can be classified
as the open cycle MHD system or the closed cycle MHD systems. In open cycle MHD systems
the working fluid is discharged to the atmosphere after the generation of the electricity whereas
the closed cycle MHD system recycles the working fluid heat sources to utilize the heat energy
present in the fluid after it comes out from the MHD chamber.

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CHAPTER 3
ALLIANCES

3.1 Working System of MHD with other Thermal Power Plant

Following are the two distinct approaches to retrofitting a thermal power plant with MHD as
topping cycle.
3.1.1 Open Cycle System
In open cycle system heat exhausted by toping MHD plant is used in steam plants such plants are
likely used as base load power plants. In this type of system potassium (K) is used as a working
fluid. High magnetic flux density 4-6 Tesla and superconducting magnet are involved.
Temperature ranges in between 2300 to 2700°C. Residual gases are exhausted into the
atmosphere.

Figure 9: An open cycle Coal Fired MHD system

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3.1.2 Closed Cycle System
In this type of system high magnetic flux density 4-6 Tesla and superconducting magnet are
involved. Temperature of closed cycle system is quite lesser than that of open cycle system i.e.
1400°C.[15] Residual gases are recycled again in the plant by doing this efficiency of the plant
increases.

Figure 10: A Closed cycle MHD System

3.2 Alliance of MHD with Convectional Power Plant

The serious challenge of present time is to cope with the severe energy crises as well as fuel
consumption. As we already know that the existing energy generating plants are failed to meet
the rising demand of energy so repowering old power station with modern MHD plant could be
satisfactory in technical sense. By integrating MHD power generating plant with conventional
thermal power plants successfully meet the energy crises and also save the fuel consumption.
The major aim of doing this is to increase the power capacity, efficiency and reduction of
19
pollution. The exhaust of MHD generator is almost as hot as the flame of conventional steam
boiler by using the exhaust gases of MHD generator into a boiler to make the steam, both MHD
and steam Rankine cycle can convert thermal energy of fossil fuels into electricity with an
improving efficiency of typical coal fired thermal power plant from 35% to 60% or more. If
triple cycle, including a MHD generator, a gas turbine and a steam turbine is utilized than
efficiency greater than 65 to 70% could be achieved.

3.2 Alliance of MHD Power with Gas-steam Plant

The efficiency of any existing conventional thermal power plant can be improved by repowering
MHD could be a out a number of combined cycle gas stream will offer 40 to very good option
with steam plant as bottoming unit. After wide range of extensive research and studies carried
55% but on the other hand combined cycle MHD-steam plant would be able to achieve
efficiency of 60% or more plants with coal gasification than MHD-steam plant would. If
comparison is made between conventional combined cycle gas-steam plants and combined cycle
MHD steam be a topping plant with steam bottoming.

Figure 11: Coal fired MHD topping unit with steam turbine bottom unit

20
3.3 Alliance of MHD with Nuclear Power Plant
Magneto hydrodynamics (MHD) is integrated with nuclear reactor either nuclear fission or
fusion. Operating temperature of this type of reactors is about 2000°C.Pumping coolant of
reactor into MHD generator before heat exchanger an estimated efficiency of 60% can be
released. Power generation system with nuclear fission reactor must be increased in order to
reduce CO2 emission.

Figure 12: A typical closed cycle scheme for nuclear source

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CHAPTER 4
RESULTS AND DISCUSSION

4.1 Possible development of MHD Power Generation

Since the invention of MHD power generating technology a lot of research and development is in
progress. This paper also highlights the possible development in energy conversion using liquid
metal instead of gases in MHD generators. In liquid metal magneto hydrodynamics energy
conversion (LMMHDEC) thermodynamic fluid i.e. gas or vapor is mixed with electro dynamic
fluid i.e. liquid metal (Li) because heat capacity of liquid is greater than gases and as a result
high thermal energy conversion reached approximately near to the ideal Carnot cycle Liquid
metal magneto hydrodynamics energy conversion. (LMMHDEC) was proposed by Elliott is
based upon high temperature Rankine cycle. In LMMHDEC lithium (Li) is used as MHD fluid
and cesium (Cs) is used as a vaporizable fluid.

Figure 13: Schematic Of two-phase cycle generator system.

This vaporizable fluid ionizes and accelerates the MHD liquid through a strong magnetic field at

22
higher velocity. When MHD liquid passes through intensive magnetic field with high velocity its
kinetic energy is directly converted into electrical energy. The MHD fluid and vaporizable fluid
are separated before passing through MHD generator with the help of separator and remaining
liquid fluid is allowed to pass through MHD generator to generate electricity. After leaving
MHD generator the liquid metal returns back. By source device the vaporizable fluid which
separates from to the mixer nozzle. Passing through a diffuser and heat liquid metal at separator
flows through regenerative heat exchanger and condenser unit then returns back to mixer loop.

4.2 Advantages and Disadvantages

Conventional coal-fired thermal power plants can achieve a maximum efficiency of about 35%
whereas this efficiency can be enhanced up to 50% - 60% by implementing the MHD generators
which utilize the energy from the hot gas-plasma prior to send it to standard steam turbines. The
MHD generator generates electrical energy by recycling the heat energy from the hot plasma
which remains sufficiently hot to boil water to drive the steam turbines to produce additional
power. In MHD generators there are no solid moving parts and hence frictional or mechanical
losses ere very less. Also wear and tear is almost negligible. Running cost is less compared to the
conventional thermal power plant. Compared to the conventional thermal power plants MHD
generators contribute less in pollution in the atmosphere as it is not generating any waste or
pollutants. CO2 emission is negligible and could be avoided in the MHD power generation
schemes. The higher cost of the required for the construction of MHD systems is one of the
major hurdles in applications of MHD systems. Huge amount of magnetic field is required which
needs a special design, higher cost and magnetic shielding in some case. Plasma or ionized fluid
velocity must be high for large amount of energy generation.

In MHD the thermal pollution of water is eliminated. (Clean Energy System) Use of MHD plant
operating in conjunction with a gas turbine power plant might not require to reject any heat to
cooling water. These are less complicated than the conventional generators, having simple
technology. There are no moving parts in generator which reduces the energy loss. These plants
have the potential to raise the conversion efficiency up to 55-60%. Since conductivity of plasma
is very high (can be treated as infinity). It is applicable with all kind of heat source like nuclear,
thermal, thermonuclear plants etc. Extensive use of MHD can help in better fuel utilization. It
contribute greatly to the solution of serious air and thermal pollution faced by steam plants.

23
The construction of superconducting magnets for small MHD plants of more than 1kW electrical
capacity is only on the drawing board. Difficulties may arise from the exposure of metal surface
to the intense heat of the generator and form the corrosion of metals and electrodes. Construction
of generator is uneconomical due to its high cost. Construction of Heat resistant and non-
conducting ducts of generator & large superconducting magnets is difficult. MHD without
superconducting magnets is less efficient when compared with combined gas cycle turbine.

24
 CHAPTER 5
CONCLUSION

Electrical energy generation is essential for the survival of the modern society. Fossil fuels are
limited and create pollution. Also the conventional power generation systems using fossil fuel
have lesser efficiency due to a higher amount of losses in different sections of the plants. MHD is
found as a nonconventional energy generation system which has the capability to enhance the
thermal power plant efficiency significantly. Also the MHD systems can be utilized alone to
harvest the electrical energy from hot plasma in many industrial applications. The channel
geometry, electrode geometry, fluid properties and the other design parameters are extremely
crustal for the performance and efficiency of the MHD system. As the velocity and magnetic
field strength are two major parameters for electric power generation the superconducting
magnets are promising to enhance the system performance. Also plasma generation needs
seeding elements to reduce the heat energy requirement in MHD systems. Though the liquid
metals can provide a highly conductive paths in MHD systems but its velocity is reduced
compared to the gas-plasma. MHD generation is very promising in the multimodal power
generation systems when coupled with the thermal power plant. With the development of the
computational fluid dynamics and other computer simulation tools the opportunities to explore
the MHD technique and the systems are open in recent time. More research investigation arse
required in various parts of the MHD systems such as fluid, electrodes, magnetic field and the
system geometry.

All the conventional thermal and hydro power plants are associated with immense losses due to
thermo mechanical and hydro mechanical operating systems. This causes various efficiency losses
i.e. mechanical breakage, thermal leakage, frictional losses. 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 MHD combined
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 overcome and MHD system would transform itself from non- conventional
to conventional energy sources. The conventional conversion systems have significant losses
25
(thermodynamics conversion) and these traditional systems are also failed to fulfill the needs of
energy of the modern world. So, the performance from the point of efficiency and reliability is
limited which can be improved by the combined operation with MHD generators. MHD generator
has no moving part which allows working at higher temperature i.e. around 3000°C without any
mechanical losses. In near future, MHD power generation system can improve the efficiency of
other conventional systems.

26
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