Internal water tank solar heat exchanger

Abstract

A heat exchanger which is adapted to an existing water tank to allow it to be heated or cooled using a hot or cold toxic or non-toxic liquid. Solar collectors, other heat sources and heat pumps can provide hot or cold liquids. To transfer this heat economically to an existing hot water tank requires a simple, efficient, heat exchanger, which can be easily adapted to the existing tank. The invention recited fills this need by simply screwing into the existing hot or cold water tank and allows heat or cold to be added or extracted via a simple fluid loop which is double wall isolated for toxic and non-toxic heat exchange fluids.

1 . An insertable double wall, in-tank heat exchange adapter for existing water tanks, comprised of a heat exchanger having a tubular element, an inlet, and an outlet defining a flow path for heat exchange fluid; an adapter on which said heat exchanger is mounted; said adapter having a male threaded portion surrounding an open port through which said heat exchanger extends adapted to screw into a threaded port provided on a water tank; and an outlet/inlet port provided on the adapter surrounded by a complementary female (or male) threaded portion which matches the male threaded portion and communicates with the open port to allow the supply or withdrawal of fluid to or from the tank when the adapter is connected thereto.  
   
   
       2 . An insertable heat exchanger according to  claim 1  which has double isolated heat exchange fluid tubes and a path for all leaking water or heat exchange fluids to exit outside of the water tank.  
   
   
       3 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed with flexible/foldable foil sheets, or flexible/bendable bristles, or flexible/bendable foil fins, which can be collapsed or bent for insertion and fold out or spring back in the hot water tank to increase the heat transfer surface in contact with the water to be heated.  
   
   
       4 . A union type coupling to allow the heat exchanger according to  claim 1  to be inserted with an adapter union so it does not need to be rotated inside the tank and can be bent to allow insertion from both top and side ports and to avoid other tank inserts, such as heating elements and temperature measuring devices.  
   
   
       5 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed of flexible/foldable foil sheets.  
   
   
       6 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed of flexible/bendable bristles.  
   
   
       7 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed of flexible/bendable foil fins.  
   
   
       8 . An insertable in-tank heat exchanger according to  claim 1  which screws into the sacrificial anode port and has an integral sacrificial anode built into it.  
   
   
       9 . An insertable in-tank heat exchanger according to  claim 1  with fluid tubes shaped as D's back to back, to form a round core.  
   
   
       10 . An insertable in-tank heat exchanger according to  claim 1  with fluid tubes formed from a single tube with an internal separator.  
   
   
       11 . An insertable in-tank heat exchanger according to  claim 1  with fluid tubes formed as a spur tube (tube inside a tube), with fluid flowing inside the center tube and returning in the annular space or vice versa.  
   
   
       12 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed as spiral flutes.  
   
   
       13 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed as stacked flutes.  
   
   
       14 . An insertable in-tank heat exchanger according to  claim 1  in which the second heat exchanger wall is formed as columnar flutes.