Thermoacoustic Thermomagnetic Generator

Abstract

This Thermoacoustic Thermomagnetic Generator uses the thermal gradient in thermoacoustic waves to periodically raise the temperature of a thermomagnetic material past its Curie point so that it alternates between magnetic and non-magnetic states. In conjunction with a stator, induction windings and magnet, the metal alloy forms a magnetic circuit that is periodically interrupted and re-established by the action of the thermoacoustic waves. The expanding and collapsing magnetic field induces an alternating current in the stator windings. The resultant generator has no moving parts. This Thermoacoustic Thermomagnetic Generator embodies hot and cold heat exchangers, a working fluid contained in a reservoir that is divided into hot and cold zones, a resonant waveguide means and an electrical generating means that are typical of the art of thermoacoustic engine-generators, but the thermal-to-electric conversion means and process are entirely unique. This basic arrangement of components can be scaled in size from the micro-miniature to the very large. The thermoacoustic thermomagnetic generators can also be arrayed in multiple units with common waveguide, housing and hot and cold heat exchanger means, such as in a panel array of multiple miniature units.

1 - 14 . (canceled)  
   
   
       15 . A Thermoacoustic Thermomagnetic Generator comprised of: 
 a) a combination waveguide and hot-side heat exchanger means for thermally amplifying and directing thermoacoustic waves through a contained elastic working fluid;    b) a stator means of ferromagnetic or magnetically permeable material for supporting and channeling magnetic fields;    c) a plurality of induction windings for conducting electric current;    d) a magnetic circuit opening and closing means of thermomagnetic material which is able to change states from magnetic to non-magnetic in response to changes in temperature and so disposed as to bridge the poles of the stator means to complete a magnetic circuit;    e) a magnetic field generating means magnetically coupled to the poles of the stator means;    f) a housing means which in conjunction with the waveguide contains the generator components and working fluid;    g) a thermal insulating means which divides the housing means into two sections, a hot section and a cold section;    h) a cold-side heat exchanger means to cool the working fluid;    i) a component sharing and configuration means so that multiple thermomagnetic generators can be configured in arrays that share a common waveguide-heat exchanger means, housing means, thermal insulating means and cold side heat exchanger means.    j) a pumping means to periodically circulate the working fluid from the cold section to the hot section of the engine;    
   
   
       16 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which the waveguide in the hot section acts as both a waveguide and a hot-side heat exchanger that conducts thermal energy from an external source through the wall of the waveguide in order to heat the elastic working fluid contained therein.  
   
   
       17 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which acoustic waves are caused to propagate through the working fluid contained within the waveguide, said acoustic waves being amplified by thermal energy in order to increase their energy in terms of thermal amplitude and pressure amplitude.  
   
   
       18 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which the thermal insulating means serves as a barrier between the waveguide and hot-side heat exchanger, and the cold section of the housing in which the thermomagnetic generator resides.  
   
   
       19 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which the magnetic circuit opening and closing means extends through the thermal insulating means from the cooler section of the housing into the hot-side waveguide section in order that the thermoacoustic waves can impinge on the magnetic circuit opening and closing means.  
   
   
       20 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which the magnetic circuit opening and closing means is a thermomagnetic or pyromagnetic material which changes state from a ferromagnetic condition to an austenitic non-magnetic condition when its temperature is periodically increased past its Curie Point temperature by the thermal energy transported by the thermoacoustic waves impinging upon it.  
   
   
       21 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which a magnetic field generating means is physically and magnetically coupled to a magnetically permeable stator means capable of supporting a magnetic field and channeling magnetic lines of force.  
   
   
       22 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which the poles of the stator means are physically and magnetically connected by the magnetic circuit opening and closing means in order to complete a magnetic circuit or loop of magnetic force.  
   
   
       23 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which induction windings are so disposed as to be in physical proximity with and magnetically coupled to the stator means so that the periodic opening and closing of the magnetic circuit creates a magnetic flux in the stator means that induces an alternating electric current in the induction windings.  
   
   
       24 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which thermally amplified thermoacoustic waves propagating through the working fluid are directed by the waveguide to impinge upon the magnetic circuit opening and closing means and periodically increase the temperature amplitude of the magnetic circuit opening and closing means past its Curie Point thereby periodically opening and closing the magnetic circuit and thereby producing a changing magnetic flux in the stator means and inducing an alternating electric current in the induction windings.  
   
   
       25 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which an external cold-side heat exchanger cools the working fluid exiting the waveguide and returns it to the cooler section of the housing.  
   
   
       26 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which an external source of thermal energy is converted into electrical energy.  
   
   
       27 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which Thermomagnetic Generators can be arrayed in multiple units with a common waveguide and hot-side heat exchanger means, housing means, thermal insulating means and cold-side heat exchanger means.  
   
   
       28 . The Thermoacoustic Thermomagnetic Generator as claimed in  claim 15 , in which Thermoacoustic Thermomagnetic Generators can be scaled in size and be arrayed in multiple miniature units with a common waveguide-heat exchanger means, housing means, thermal insulating means and cold-side heat exchanger means in a panel array.