Geothermal heat exchange using coil assemblies

Abstract

A heat-exchange system includes a casing and a coil assembly disposed within the casing. The coil assembly may include a supply inlet configured to receive heat-exchange fluid and a first manifold disposed downstream of the supply inlet. The first manifold may include a supply conduit and a number of manifold outlets. The coil assembly may include a number of exchange conduits coupled, at a first end, to one of the plurality of manifold outlets. A second manifold may be disposed downstream of the first manifold, and may include a return conduit and a number of manifold inlets, where each exchange conduit is coupled, at a second end, to one of the manifold inlets. A return outlet may be configured to return the heat-exchange fluid.

We claim: 
     
         1 . A heat-exchange system comprising:
 a casing; and   a coil assembly disposed within the casing, the coil assembly comprising:
 a supply inlet configured to receive heat-exchange fluid; 
 a first manifold disposed downstream of the supply inlet, the first manifold comprising a supply conduit and a plurality of manifold outlets; 
 a plurality of exchange conduits, wherein each exchange conduit is coupled, at a first end, to one of the plurality of manifold outlets; 
 a second manifold disposed downstream of the first manifold, the second manifold comprising a return conduit and a plurality of manifold inlets, wherein each exchange conduit is coupled, at a second end, to one of the plurality of manifold inlets; and 
 a return outlet configured to return the heat-exchange fluid. 
   
     
     
         2 . The system of  claim 1 , the casing comprising a perforated polyvinyl chloride (PVC) pipe. 
     
     
         3 . The system of  claim 1 , the casing comprising an annular wall. 
     
     
         4 . The system of  claim 3 , the casing further comprising a lower wall at least partially closing a first end of the annular wall. 
     
     
         5 . The system of  claim 4 , the casing further comprising an upper wall at least partially closing a second end of the annular wall. 
     
     
         6 . The system of  claim 3 , the casing further comprising at least one aperture defined in the annular wall, the at least one aperture being configured to allow water to pass therethrough. 
     
     
         7 . The system of  claim 1 , further comprising at least one additional coil assembly disposed within the casing. 
     
     
         8 . The system of  claim 7 , wherein the at least one additional coil assembly is operatively coupled to the coil assembly. 
     
     
         9 . The system of  claim 8 , wherein the coil assembly and the at least one additional coil assembly are operatively coupled in series and/or in parallel. 
     
     
         10 . The system of  claim 1 , wherein at least one of the first manifold and the second manifold has a length of at least approximately three feet. 
     
     
         11 . The system of  claim 1 , the plurality of exchange conduits comprising between 75 and 125 exchange conduits. 
     
     
         12 . The system of  claim 11 , the plurality of exchange conduits comprising 117 exchange conduits. 
     
     
         13 . The system of  claim 1 , each of the plurality of exchange conduits having a length of between at least approximately 15 feet and 25 feet. 
     
     
         14 . The system of  claim 13 , each of the plurality of exchange conduits having a length of at least approximately 19.5 feet. 
     
     
         15 . The system of  claim 1 , wherein the plurality of exchange conduits are arranged in a parallel orientation with respect to each other. 
     
     
         16 . The system of  claim 1 , wherein at least one of the plurality of exchange conduits is coiled with respect to a central axis. 
     
     
         17 . The system of  claim 16 , further comprising at least one spacer disposed between adjacent loops of the at least one of the plurality of exchange conduits. 
     
     
         18 . The system of  claim 17 , the at least one spacer comprising a plurality of spacers positioned to maintain an at least approximately constant gap between each pair of adjacent loops. 
     
     
         19 . The system of  claim 1 , wherein the casing is configured to be disposed in a heat-exchange cavity, the heat-exchange cavity comprising at least one of an underground water storage reservoir, an above-ground water storage reservoir, and a borehole. 
     
     
         20 . A method, comprising:
 positioning a coil assembly within a casing, the coil assembly comprising:
 a supply inlet configured to receive heat exchange fluid; 
 a first manifold disposed downstream of the supply inlet, the first manifold comprising a supply conduit and a plurality of manifold outlets; 
 a plurality of exchange conduits, wherein each exchange conduit is coupled, at a first end, to one of the plurality of manifold outlets; 
 a second manifold disposed downstream of the first manifold, the second manifold comprising a return conduit and a plurality of manifold inlets, wherein each exchange conduit is coupled, at a second end, to one of the plurality of manifold inlets; and 
 a return outlet configured to return the heat exchange fluid; and 
   positioning the casing within a heat-exchange cavity.