Enriched high conductivity geothermal fill and method for installation

Abstract

A geothermal fill material composed of one or more high heat conductivity materials alone or in combination to produce a fill that can be used to cover and encapsulate geothermal ground coils to improve heat transfer between the ground and the fluid inside the coils and to improve the rate of heat recovery of the fill in contact and in the vicinity of the coils. These materials can be in the form of particulates, rods or wire mesh and in any combination. Further enhancements are to cover this high conductivity material with low conductivity materials near the surface of the ground or to install the coils in a ground coil field below a structure in order to reduce ground heat loss to the atmosphere in the winter and to reduce heat gain from the atmosphere in the summer.

1 . A process whereby materials with higher heat conductivity than natural ground formations, which are typically 1.1 W/m.K or lower, are selected and are used alone or in combination with natural ground materials such as sand and gravel to produce a mixture with a heat conductivity value of 1.5 W/m.K or higher and using this mixture to cover and encapsulate geothermal ground coils to improve heat transfer between the ground and the fluid inside the coils and to improve the heat recovery of the ground in contact and in the vicinity of the coils.  
   
   
       2 . A method of  claim 1  wherein the higher heat conductivity material is metallic in nature and can be in any form such as wire mesh and rods similar to those used to reinforce concrete or in the form of particulates such as scrap metal from salvage operation or crushed aluminum cans from recycle centers.  
   
   
       3 . A method of  claim 1  whereby the higher conductivity material consists of scrap materials from ceramic or glass cookware production such as Corningware® or Pyrex® brand products having a heat conductivity value of 1.5 W/m.K or higher.  
   
   
       4 . A method of  claim 1  whereby the higher conductivity material is mineral in nature such as bentonite iron ore, bauxite and other metal containing minerals and ores that have a heat conductivity value of 1.5 W/m.K or higher.  
   
   
       5 . A method of  claim 1  whereby the higher conductivity material is a polymer that has metal or other high conductivity material as fill and has a heat conductivity value of 1.5 W/m.K or higher.  
   
   
       6 . A process according to  claim 1  where the heat loss in winter and the heat gain in summer between the ground coil field and the atmosphere is minimized by installing the ground coil field below a structure or below a layer of low heat conductivity material having a heat conductivity value of less than 1.0 W/m.K.  
   
   
       7 . A method of encapsulating geothermal ground coils with said high conductivity fill mixture to improve heat transfer between the ground and the fluid in the coils comprising: 
 A. mixing particulate materials with high heat conductivity values of 1.5 W/m.K or greater to produce a high heat conductivity fill mixture of 1.5 W/m.K or greater.    B. placing the high conductivity fill mixture beneath a plurality of geothermal ground coils to form a bottom layer.    C. placing the high conductivity fill mixture around said ground coils to a height equal to the top of these coils.    D. placing the high conductivity fill mixture over said ground coils to form a top layer.    
   
   
       8 . The method of  claim 7  whereby metallic mesh or metallic rods, similar to those used to reinforce concrete are placed horizontally between the ground coils and the bottom and top layers of the high conductivity fill mixture and a plurality of more metal rods or metallic wire mesh are positioned vertically or at any angle to form a grid which would improve heat conductivity and heat recovery to the high conductivity fill mixture in contact and in the vicinity of the ground coils. Grout can be used to bond the ground coils to the wire mesh, rods and high conductivity fill mixture to further improve heat transfer. The elimination of any of these steps does not void the spirit of this invention.