Energy transfer machines

Abstract

A novel engine for producing power from a temperature differential with additional benefits of low cost, high efficiency, quiet operation minimal wear of components, and the ability to produce power or cooling from low grade heat sources.

1 - 19 . (canceled) 
     
     
         20 . An energy transfer machine comprising:
 a conduit having a first end and a second end and containing a fluid;   a pressure-displacement coupled interface within the conduit, the pressure-displacement coupled interface separating the first end of the conduit from the second end of the conduit;   a high pressure zone communicating with the conduit through a first high pressure valve at the first end of the conduit and a second high pressure valve at the second end of the conduit, pressure in the high pressure zone being produced by expansion of water as it freezes or is cooled to near freezing; and   a low pressure zone communicating with the conduit through a first low pressure valve at the first end of the conduit and a second low pressure valve on the second end of the conduit,   the first high pressure valve, the second high pressure valve, the first low pressure valve and the second low pressure valve being operable to convert pressure in the high pressure zone into displacement of the pressure-displacement coupled interface.   
     
     
         21 . The energy transfer machine of  claim 20  in which the pressure in the high pressure zone is produced by expansion of water as it freezes. 
     
     
         22 . The energy transfer machine of  claim 21  in which the fluid comprises the freezing water in a liquid matrix. 
     
     
         23 . The energy transfer machine of  claim 22  in which the liquid matrix is a non-freezing hydrophobic liquid. 
     
     
         24 . The energy transfer machine of  claim 23  in which the non-freezing hydrophobic liquid is oil or gasoline. 
     
     
         25 . The energy transfer machine of  claim 22  further comprising mixing means arranged to keep the freezing water suspended in the liquid matrix. 
     
     
         26 . The energy transfer machine of  claim 25  in which the mixing means is arranged to keep water droplets and/or ice particles of the freezing water small. 
     
     
         27 . The energy transfer machine of  claim 20  further comprising an output device coupled to the pressure-displacement coupled interface for converting the reciprocal motion of the pressure-displacement coupled interface into electrical energy. 
     
     
         28 . The energy transfer machine of  claim 20  in which the low pressure zone and high pressure zone, in combination with the conduit, comprise passageways forming a closed loop. 
     
     
         29 . The energy transfer machine of  claim 28  in which there is unidirectional flow around the closed loop. 
     
     
         30 . The energy transfer machine of  claim 20  in which the pressure-displacement coupled interface comprises a piston or diaphragm. 
     
     
         31 . The energy transfer machine of  claim 30  in which the piston or diaphragm has equal surface area at each end of the piston or diaphragm against which the fluid exerts pressure. 
     
     
         32 . The energy transfer machine of  claim 31  in which the pressure-displacement coupled interface comprises a free piston. 
     
     
         33 . The energy transfer machine of  claim 20 , further comprising:
 a first accumulator on the high pressure zone to accommodate pressure variation in the high pressure zone; and   a second accumulator on the low pressure zone to accommodate pressure variation in the low pressure zone.   
     
     
         34 . The energy transfer machine of  claim 20 , further comprising an accumulator at one or more of the first end and the second end of the conduit. 
     
     
         35 . The energy transfer machine of  claim 20 , further comprising a control system configured to send control signals to the first high pressure valve, the second high pressure valve, the first low pressure valve, and the second low pressure valve,
 the first high pressure valve, the second high pressure valve, the first low pressure valve, and the second low pressure valve opening and closing in response to control signals from the control system.   
     
     
         36 . The energy transfer machine of  claim 20 , further comprising a first rebound spring and a second rebound spring, the first rebound spring lying within the conduit between the first end of the conduit and the pressure responsive element and the second rebound spring lying within the conduit between the second end of the conduit and the pressure-displacement coupled interface.