Composite heat exchanger shell and buoyancy system and method

Abstract

A heat exchanger includes a shell made of a composite material, and a heat exchanger housed substantially within the shell. The shell is made of a composite material further comprises planks positioned in the outer periphery of the shell. The planks, in one embodiment, are substantially hollow or include substantially hollow portions. In some embodiments, the planks are formed of pultruded plastic. The shell of the heat exchanger further includes layers of fiberglass. The pultruded plastic planks are sandwiched between at least a first layer of fiberglass and a second layer of fiberglass. The layers of fiberglass are infused with resin. A floating portion of an Ocean Thermal Energy System includes shells made of composite material. The cold seawater intake can also be an elongated tube of composite material.

What is claimed: 
     
         1 . A heat exchanger comprising:
 a shell made of a composite material; and   a heat exchanger housed substantially within the shell.   
     
     
         2 . The heat exchanger of  claim 1  wherein the shell of composite material further comprises planks positioned in the outer periphery of the shell. The heat exchanger of  claim 2  wherein the planks are substantially hollow. 
     
     
         3 . The heat exchanger of  claim 2  wherein the planks are formed of pultruded plastic. 
     
     
         4 . The heat exchanger of  claim 1  wherein the composite material is further comprised of:
 pultruded plastic core planks; and 
 layers of fiberglass, the pultruded plastic planks sandwiched between at least a first layer of fiberglass and a second layer of fiberglass. 
 
     
     
         5 . The heat exchanger of  claim 1  wherein the layers of fiberglass are infused with resin. 
     
     
         6 . The heat exchanger of  claim 5  wherein the layers of fiberglass are infused with resin using a Vacuum-Assisted Resin Transfer Molding (VARTM) process. 
     
     
         7 . The heat exchanger of  claim 1  wherein the shell further comprises:
 a first end; 
 a second end; and 
 at least one metal flange coupled to one of the first end or second end of the shell. 
 
     
     
         8 . The heat exchanger of  claim 7  wherein at least one metal flange is comprised of:
 an inner termination ring having inner trap-lock grooves therein; and 
 an outer termination ring having inner trap-lock grooves therein. 
 
     
     
         9 . The heat exchanger of  claim 1  wherein the shell of composite material is buoyant. 
     
     
         10 . The heat exchanger of  claim 1  wherein the shell of composite material is over 70 meters in length. 
     
     
         11 . An apparatus for forming elongated tubes of composite material, the apparatus comprising:
 a floating base;   a molding region attached to the base, the molding region including a core ring for receiving a core material;   a fiber supply region for providing a substantially continuous supply of a fiber to the molding region, the fiber supply region supplying fiber to an inner region of the core ring and an outer region of the core ring; and   a resin infusion apparatus for infusing the fiber with resin.   
     
     
         12 . The apparatus for forming elongated tubes of composite material of  claim 11  further comprising a core material that is inserted into the core ring. 
     
     
         13 . The apparatus for forming elongated tubes of composite material of  claim 11  further comprising a core material that is inserted into the core ring, the core material including elongated planks of plastic. 
     
     
         14 . The apparatus for forming elongated tubes of composite material of  claim 11  further comprising a core material that is inserted into the core ring, the core material including elongated planks of pultruded plastic having hollow portions therein. 
     
     
         15 . The apparatus for forming elongated tubes of composite material of  claim 11  further comprising a vacuum assisted resin infusion apparatus to apply a vacuum to a portion of the molding chamber. 
     
     
         16 . The apparatus for forming elongated tubes of composite material of  claim 11  wherein the molding process occurs at a site where the elongated tubes of composite material are used to form a floating heat exchanger for an Ocean Thermal Energy System. 
     
     
         17 . The apparatus for forming elongated tubes of composite material of  claim 11  wherein a plurality of elongated planks are positioned around the ring core in forming the elongated tubes. 
     
     
         18 . The apparatus for forming elongated tubes of composite material of  claim 11  further comprising an apparatus for applying a metal flange to at least one of the ends of the elongated tube. 
     
     
         19 . A floating portion of an Ocean Thermal Energy System comprising:
 a platform;   a plenum attached to the platform;   a cold seawater intake attached to the plenum;   a plurality of heat exchangers attached to the plenum, the heat exchangers including pumps for moving the cold seawater from the plenum through the heat exchangers, wherein the heat exchangers include shells made of composite material.   
     
     
         20 . A floating portion of an Ocean Thermal Energy System of  claim 19  wherein the cold seawater intake is an elongated tube of composite material.