Underwater cooling assembly

Abstract

A lightweight underwater cooling assembly with a high cooling capacity comprises: an assembly of heat exchanger tubes ( 4 ) arranged in a submerged refrigerant boiling chamber ( 5 ); a thin walled water cooled condenser ( 6 ) in which refrigerant vaporized in the boiling chamber ( 5 ) is condensed and from which condensed refrigerant is recirculated into the boiling chamber ( 5 ); and a thin walled pressure compensating membrane ( 9 ) which maintains the fluid pressure (˜p sea ) within the boiling chamber ( 5 ) and condenser ( 6 ) substantially similar to the fluid pressure (p sea ) of the (sea) water surrounding the submerged refrigerant boiling chamber ( 5 ).

1 . An underwater cooling assembly, comprising:
 an assembly of heat exchanger tubes arranged in a submerged refrigerant boiling chamber;   a water cooled condenser in which refrigerant vaporized in the boiling chamber is condensed and from which condensed refrigerant is recirculated into the boiling chamber; and   a pressure compensating membrane which maintains the fluid pressure within the boiling chamber substantially similar to the fluid pressure of the water surrounding the submerged refrigerant boiling chamber.   
   
   
       2 . The underwater cooling assembly of  claim 1 , wherein the assembly forms part of an underwater gas and/or crude oil production assembly. 
   
   
       3 . The underwater cooling assembly of  claim 2 , wherein the assembly is configured to cool a production stream of natural gas and/or crude oil and/or underwater equipment, such as one or more electrical motors and/or gas compressors. 
   
   
       4 . The underwater cooling assembly of  claim 1 , wherein the condenser is an elongate thin walled substantially vertically oriented vessel with an internal permeable reinforcement frame and external cooling fins and wherein the pressure compensating membrane also keeps the pressure within the condenser substantially similar to the pressure of the surrounding water. 
   
   
       5 . The underwater cooling assembly of  claim 1 , wherein the boiling chamber and condenser have an outer wall, which is less than 3 millimeters thick.