Halbach array linear alternator for thermo-acoustic engine

“…This shows the potential for developing inexpensive electricity generators for energy recovery from waste heat sources based on thermoacoustic technology. Later, a combustion driven prototype was also developed to fully demonstrate the development of low cost thermoacoustic electricity generators for rural communities that are off the national grid [20,21]. Chen et al [22] also reported their development of low cost two-stage travelling-wave thermoacoustic generators to generate electricity from waste heat energy of cooking stoves.…”

Section: Introductionmentioning

confidence: 99%

A two-stage traveling-wave thermoacoustic electric generator with loudspeakers as alternators

Kang

Cheng

et al. 2015

Applied Energy

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This paper presents the design, construction and tests of a traveling-wave thermoacoustic electric generator. A two-stage travelling-wave thermoacoustic engine converts thermal energy to acoustic power. Two low-impedance linear alternators (i.e., audio loudspeakers) were installed to extract and convert the engine's acoustic power to electricity. The coupling mechanism between the thermoacoustic engine and alternators has been systematically studied numerically and experimentally, hence the optimal locations for installing the linear alternators were identified to maximize the electric power output and/or the thermal-to-electric conversion efficiency. A ball valve was used in the loop to partly correct the acoustic field that was altered by manufacturing errors. A prototype was built based on this new concept, which used pressurized helium at 1.8 MPa as the working gas and operated at a frequency of about 171 Hz. In the experiment, a maximum electric power of 204 W when the hot end temperature of the two regenerators reaches 512℃ and 452℃, respectively. A maximum thermal-to-electric efficiency of 3.43% was achieved when the hot end temperature of the two regenerators reaches 597℃ and 511℃, respectively. The research results presented in this paper demonstrate that multi-stage travelling-wave thermoacoustic electricity generator has a great potential for developing inexpensive electric generators.

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“…2,3) In recent years, HAMs have been widely used for highly efficient electromagnetic devices, in addition to mechanical devices such as electric motors, tape recorders and undulators at synchrotron radiation facilities. [4][5][6][7][8][9] However, HAMs are still subject to serious problems in mass production, because HAMs require bonding processes using adhesives and/or fixtures. Such processes increase both the difficulty in precise assembly and the mass production costs, which make it impossible to produce a number of miniature or large sized HAMs.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Multipole Magnets with Enhanced Flux Density Using Anisotropic Bond Magnets for Miniature Optical Pickup Devices

et al. 2015

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A prototype magnetizing fixture was designed based on magnetic flux patterns simulated using the three-dimensional finite-element method of the JMAG software package. Rectangular shaped anisotropic bond magnets with dimensions of 6×12×24 mm were magnetized to multipoles using the prototype and a pulse power source. The result was significant enhancement perpendicular to the surface component of magnetic flux density (Bz) in the hard-axis compared with Bz for conventional simple magnets, of which the front and back surfaces are magnetized to opposite polarities. Moreover, Bz reached the close value for the Halbach arrayed magnet, 0.24 T, with the same body size fabricated for the attainment target. The enhanced Bz was attributed to the cusp field formed by the flux from both side coils. Demonstrations indicated that the cusp field out of the easy-axis could be efficiently enhanced due to focusing of the flux.

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Halbach array linear alternator for thermo-acoustic engine

Cited by 26 publications

References 11 publications

Design and development of a low-cost, electricity-generating cooking Score-Stove™

Design and development of a low-cost, electricity-generating cooking Score-Stove™

A two-stage traveling-wave thermoacoustic electric generator with loudspeakers as alternators

Fabrication of Multipole Magnets with Enhanced Flux Density Using Anisotropic Bond Magnets for Miniature Optical Pickup Devices

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