Magnetohydrodynamic Magnetohydrodynamic (MHD)(MHD)

GeneratorGenerator

Sarah HerderSarah Herder

Aubrey SpildeAubrey Spilde

Margaret ZahllerMargaret Zahller

ESM 288ESM 288

May 17, 2006May 17, 2006

MHD power generation uses the MHD power generation uses the interaction of an electrically conducting interaction of an electrically conducting fluid with a magnetic field to convert part fluid with a magnetic field to convert part of the energy of the fluid directly into of the energy of the fluid directly into electricityelectricity

Converts thermal or kinetic energy into Converts thermal or kinetic energy into electricity electricity

WhereWhere F is the force of the acting particle (vector)F is the force of the acting particle (vector) V is the velocity of the particle (vector)V is the velocity of the particle (vector) Q is the charge of the particle (scalar)Q is the charge of the particle (scalar) B is the magnetic field (vector)B is the magnetic field (vector)

Lorentz Force Law:Lorentz Force Law:F = QvBF = QvB

Conversion EfficiencyConversion Efficiency

MHD generator alone: 10-20%MHD generator alone: 10-20%

Steam plant alone: Steam plant alone: ≈ ≈ 40%40%

MHD generator coupled with a steam MHD generator coupled with a steam plant: up to 60%plant: up to 60%

Losses Losses

Heat transfer to wallsHeat transfer to walls

FrictionFriction

Maintenance of magnetic fieldMaintenance of magnetic field

MHD + Steam plantMHD + Steam plant

What we thought in What we thought in 1975:1975: Maximum electric power generation is Maximum electric power generation is unlimitedunlimited by physical by physical

principle, principle, onlyonly by technological development by technological development

With no dynamically or thermally stressed components, the With no dynamically or thermally stressed components, the system is expected to be system is expected to be robustrobust, with high operational , with high operational safetysafety, and , and littlelittle required maintenance required maintenance

Can yield full output of power in between Can yield full output of power in between 0.3 to 0.5 seconds0.3 to 0.5 seconds Ideally suited for emergency Ideally suited for emergency back-up or reserve powerback-up or reserve power or or experimental experimental scientific usesscientific uses (pulsed power) (pulsed power)

Research under way by a number of countries including the Research under way by a number of countries including the US, China, Italy, and JapanUS, China, Italy, and Japan

ENTER: ENTER: The Department of Energy The Department of Energy (DOE)(DOE)

Called for a Called for a ‘Proof-of-Concept’‘Proof-of-Concept’ program to be program to be completed between 1983-1993completed between 1983-1993

focused development on open-cycle, coal-fired, focused development on open-cycle, coal-fired, commercial MHD power plants & creating a commercial MHD power plants & creating a database for the private sectordatabase for the private sector

Tested combinations with other power Tested combinations with other power conversion components (nuclear & steam)conversion components (nuclear & steam)

Results of DOE ResearchResults of DOE Research

““successfully proved the concept of MHD successfully proved the concept of MHD technology” technology”

Program was Program was discontinued in 1993discontinued in 1993 due to the due to the high cost of designing, constructing, and high cost of designing, constructing, and operating a complete systemoperating a complete system Much higher than the corresponding costMuch higher than the corresponding cost for other for other

coal-fired power generation options already in usecoal-fired power generation options already in use Lower efficiencyLower efficiency than developing gas turbine than developing gas turbine

technologytechnology

More Results of DOE More Results of DOE ResearchResearch

Knowledge benefits: Knowledge benefits: database of technologies for pressurized database of technologies for pressurized

high-temperature gas heatershigh-temperature gas heaters Contributed to subsequent clean coal Contributed to subsequent clean coal

technology projectstechnology projects

““NO realized economic, environmental, NO realized economic, environmental, or security benefits”or security benefits”

(Total Money spent on MHD program: $1.02 Billion by government & $90 million by industry (in constant 1999 dollars))

““Lessons Learned” Lessons Learned” (according to the DOE)(according to the DOE)

““Private sector interest in developing a technology, as evidenced Private sector interest in developing a technology, as evidenced by a willingness to cost share in the demonstration process, must by a willingness to cost share in the demonstration process, must be considered.”be considered.”

““There must be an understanding of where a technology fits in an There must be an understanding of where a technology fits in an R&D portfolio from a priority standpoint, so that decision makers at R&D portfolio from a priority standpoint, so that decision makers at all levels can be provided with all the information they need to all levels can be provided with all the information they need to make the best decisions in the interest of the overall R&D make the best decisions in the interest of the overall R&D program.”program.”

““Difficult decisions to terminate programs must be made as early Difficult decisions to terminate programs must be made as early as possible and available funds redirected to the areas of greatest as possible and available funds redirected to the areas of greatest potential.”potential.”

Other uses of MHD Other uses of MHD TechnologyTechnology

The “Yamoto”: a boat The “Yamoto”: a boat built by Mitsubishi built by Mitsubishi powered solely by powered solely by MHD propulsionMHD propulsion

Can travel at up to Can travel at up to 15 km/hr15 km/hr

Final application:Final application:

Caterpillar driveCaterpillar drive uses MHD uses MHD technology to silently technology to silently power sub (no moving power sub (no moving parts) so that the Commies parts) so that the Commies can attack the US can attack the US undetected (but Sean undetected (but Sean Connery defects and saves Connery defects and saves the day)the day)

The Hunt for Red October