Low entropy heat exchanger especially for use with solar gas processors

Abstract

An apparatus and method for solar energy powered gas processing. There is disclosed a processor assembly for use in heating a process or feed gas by means of a convective heat exchanger which receives solar energy from a focused solar energy collector. A specialized heat exchanger is described, which maximizes the area upon which solar energy can radiate, as well as the available area for heat transfer to the flowing gas. Various modes for operating the processor assembly are described. The apparatus and method may be utilized to heat a gas to drive a heat engine. The apparatus and method also may be used to heat feed gasses to drive a gas processing reaction, such as for steam methane reformation or a reverse water-gas shift reaction.

1 . An apparatus for heating a feed gas comprising:
 a heat exchanger comprising:
 a rolled foil separator; and 
 a rolled corrugated foil baffle, wherein said corrugated foil baffle is rolled with said separator such that said heat exchanger comprises said foil baffle situate between windings of said foil separator; and 
   a collector for reflectively directing solar energy toward said heat exchanger thereby to heat said exchanger;   
     wherein a feed gas flows axially through said heat exchanger to be heated thereby. 
   
   
       2 . An apparatus according to  claim 1  wherein said foil separator and said foil baffle are spiral wound to define alternating windings of separator and baffle. 
   
   
       3 . An apparatus according to  claim 1  wherein said foil separator or said corrugated foil baffle comprises nickel superalloy. 
   
   
       4 . An apparatus according to  claim 1  wherein said foil separator or said corrugated baffle comprises copper alloy. 
   
   
       5 . An apparatus according to  claim 2  wherein each winding of said corrugated foil baffle has a radial thickness dimension, and wherein said radial thickness dimensions of said windings are substantially uniform. 
   
   
       7 . An apparatus according to  claim 2  wherein each winding of said corrugated foil baffle has a radial thickness dimension, and wherein said radial thickness dimensions of said windings vary as a function of the radial distance from the center of said heat exchanger. 
   
   
       8 . An apparatus according to  claim 7  wherein said radial thickness dimensions progressively decrease proceeding radially outward from the center of said heat exchanger. 
   
   
       9 . An apparatus according to  claim 1  further comprising an exchanger housing within which said heat exchanger is disposed;
 said housing and a first face of said exchanger defining a first forward chamber, wherein said collector directs solar energy to said first face of said exchanger;   said housing and a second face of said exchanger defining a second rear chamber;   
     wherein said feed gas flows from one of said chambers to the other of said chambers. 
   
   
       10 . An apparatus according to  claim 9  further comprising:
 an inlet through said housing through which feed gas enters said first chamber en route to said heat exchanger; and   a pump to move feed gas through said heat exchanger from said first chamber to said second chamber.   
   
   
       11 . An apparatus according to  claim 9  further comprising an inlet through said housing through which feed gas enters said second chamber en route to said heat exchanger; and
 a pump to move feed gas through said heat exchanger from said second chamber to said first chamber.   
   
   
       12 . An apparatus according to  claim 9  further comprising a mirror disposed in said second chamber in confronting relation to said second face of said heat exchanger, whereby solar energy passing through said heat exchanger into said second chamber is reflectively redirected toward said second face of said heat exchanger to heat said exchanger.