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Title: Double-duct liquid metal magnetohydrodynamic engine

Abstract

An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

Inventors:
 [1]
  1. (Oak Ridge, TN)
Publication Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
OSTI Identifier:
870996
Patent Number(s):
US 5637935
Assignee:
Martin Marietta Energy Systems, Inc. (Oak Ridge, TN) ORNL
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
double-duct; liquid; metal; magnetohydrodynamic; engine; internal; combustion; mhd; alternating; current; generator; combination; provide; useful; electric; energy; output; design; pistons; double; duct; configuration; containing; sodium; potassium; confined; free; located; forced; flow; forth; movement; alternatively; driven; process; lm-mhd; ducts; pass; close; proximity; hartmann; transformer; power; produced; operating; flowing; counter; directions; amount; maintained; varied; provides; variable; stroke; length; frequencies; correspond; demands; vehicular; propulsion; maintain; nearly; constant; efficiency; throughout; range; usage; automobiles; trucks; powered; transmission; converter; devices; required; metal main; magnetohydrodynamic generator; combustion process; close proximity; internal combustion; liquid metal; alternating current; mhd generator; free piston; electric energy; nearly constant; variable stroke; provides variable; stroke length; power usage; output transformer; metal magnetohydrodynamic; provide useful; energy output; containing sodium; double-duct liquid; generator provides; power converter; generator duct; engine design; mhd duct; power demand; duct configuration; duct containing; ducts pass; magnetohydrodynamic engine; /310/

Citation Formats

Haaland, Carsten M. Double-duct liquid metal magnetohydrodynamic engine. United States: N. p., 1997. Web.
Haaland, Carsten M. Double-duct liquid metal magnetohydrodynamic engine. United States.
Haaland, Carsten M. 1997. "Double-duct liquid metal magnetohydrodynamic engine". United States. doi:. https://www.osti.gov/servlets/purl/870996.
@article{osti_870996,
title = {Double-duct liquid metal magnetohydrodynamic engine},
author = {Haaland, Carsten M.},
abstractNote = {An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1997,
month = 1
}

Patent:

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  • An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has-four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann ductmore » with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.« less
  • A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal inmore » the channel. High efficiency is obtained over a wide range of frequency and power output.« less
  • A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal inmore » the channel. High efficiency is obtained over a wide range of frequency and power output. 5 figs.« less
  • Operating principles, features and applications of the Liquid Metal (LM) engine are presented. This engine combines a free-piston internal combustion engine with an MHD AC power generator. Liquid metal (LM) oscillates back-and-forth in two separate channels, driven by free pistons coupled magnetically to pistons driven by internal combustion. One of the principal breakthroughs is the concept of using double ducts in a Hartmann configuration for MHD production of alternating current. The LM flows in opposing directions in the two adjacent Hartmann ducts, thus eliminating magnetic-induced instabilities, eliminating vibration, and providing an ideal setup for attaching an output transformer on onemore » side provide to provide useful ranges of current and voltage. Because LM is used, the length of the piston stroke can be easily varied over a large range, thus making possible an engine that, changes size, according to variation in output load requirements. Increasing the stroke length results in increased compression ratio, which requires computer controlled modification of the fuel injection mixture. Higher fuel efficiencies will result, whether the engine is idling or operating at maximum power. Because of viscous dissipation losses in the LM, this engine will be more efficient for larger engines. Applications include any power generation where variable load is required, such as stationary electric generators for remote towns and cities, temporary military encampments, and mobile primary power generators for off-road and on-road automotive equipment, including caterpillars, cars, military vehicles, trucks, and trains. The advantages for automotive propulsion will be described in comparisons with current and developmental vehicles using internal combustion engines. Because the LM-engine generates electricity, an LM-engine vehicle is readily adaptable to hybrid concepts. An R&D program will be outlined for bringing the concept of the LM engine to commercial application.« less
  • A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include a straight path segment (26) and an arcuate connecting segment (36). A respective straight metal liner (92) and an arcuate metal liner (94) may be each inwardly disposed onto a metal outer shell (38) along the straight path segment and the arcuate connecting segment (36) of the exit piece. Structural arrangements are provided to securely attach the respective liners in the presence of substantialmore » flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liners can be readily removed and replaced as needed.« less