Water heating apparatus and system

Abstract

A fluid heating apparatus comprising a chamber for containing a quantity of fluid to be heated and a heating device in the chamber. The heating device comprises a hollow body having a flow inlet and a return outlet to allow a heating medium to flow through the hollow body. The hollow body has a first heat exchanging surface extending along the chamber between a fluid inlet and fluid outlet and defining a smooth, straight fluid passage between the inlet and outlet. The preferred apparatus takes the form of a thermosyphon and is particularly suited for use with a water storage tank, where it is arranged to cause thermosyphonic circulation of water between the thermosyphon and the tank.

1 . A fluid heating apparatus comprising a body defining a chamber for containing a quantity of fluid to be heated, the chamber having a fluid inlet and a fluid outlet spaced apart in a first axial direction; and means for heating the fluid in said chamber, the heating means being located in said chamber between said fluid inlet and fluid outlet, the heating means comprises a hollow body having a flow inlet and a return outlet to allow a heating medium to flow through said hollow body, wherein said hollow body comprises a first heat exchanging surface extending along the chamber in said first axial direction between said fluid inlet and said fluid outlet, said first heat exchanging surface facing an internal surface of said chamber to define a passage for said fluid therebetween, said passage extending in said first axial direction. 
   
   
       2 . An apparatus as claimed in  claim 1 , wherein said first heat exchanging surface and said internal surface of said body are substantially solid, and preferably substantially smooth, along said passage. 
   
   
       3 . An apparatus as claimed in  claim 1 , wherein said passage is substantially straight in said first axial direction. 
   
   
       4 . An apparatus as claimed in  claim 1 , wherein said hollow body substantially fills said chamber. 
   
   
       5 . An apparatus as claimed in  claim 1 , wherein said passage is substantially annular in a plane perpendicular with said first axial direction. 
   
   
       6 . An apparatus as claimed in  claim 1 , wherein the hollow body comprises an annular outer section, said first heat exchanging surface being provided by an outer external surface of said annular outer section. 
   
   
       7 . An apparatus as claimed in  claim 6 , wherein said annular outer section is sleeve shaped, and preferably substantially cylindrical in shape. 
   
   
       8 . An apparatus as claimed in  claim 6 , wherein the annular outer section has an inner external surface, the inner external surface providing a second heat exchanging surface extending between said fluid inlet and said fluid outlet. 
   
   
       9 . An apparatus as claimed in  claim 6 , wherein the hollow body includes a hollow inner section located within, and in fluid communication with, said annular outer section and having an outer surface, said outer surface providing a third heat exchanging surface extending between said fluid inlet and said fluid outlet. 
   
   
       10 . An apparatus as claimed in  claim 1 , wherein the or each heat exchanging surface is substantially solid and preferably substantially smooth. 
   
   
       11 . An apparatus as claimed in  claim 9 , wherein said inner section comprises a pipe. 
   
   
       12 . An apparatus as claimed in  claim 9 , wherein said inner section has a longitudinal axis that is substantially parallel with, and preferably substantially coaxial with, the longitudinal axis of the outer section. 
   
   
       13 . An apparatus as claimed in  claim 9 , wherein a second fluid passage is defined between the outer surface of the inner section and the inner surface of the annular outer section, said second passage being substantially straight in said axial direction. 
   
   
       14 . An apparatus as claimed in  claim 9 , wherein said flow inlet is provided on one or other of said inner or outer hollow body sections, the return outlet being provided on the other of said inner or outer hollow body sections. 
   
   
       15 . An apparatus as claimed in  claim 14 , wherein inner section is connected to said outer section at one end of the outer section, said flow inlet or return outlet being provided on the opposite end of the outer section, the other of said flow inlet or return outlet preferably being provided on the inner section adjacent said opposite end of the outer section. 
   
   
       16 . An apparatus as claimed in  claim 1 , wherein said flow inlet and return outlet are provided at the same end of the apparatus, preferably the in use top end of the apparatus. 
   
   
       17 . An apparatus as claimed in  claim 1 , wherein said fluid outlet is provided at the in use top end of the apparatus and is substantially aligned with said first axial direction, and is preferably substantially aligned with at least part of said fluid passage. 
   
   
       18 . An apparatus as claimed in  claim 17 , wherein said fluid outlet includes a fluid conduit extending from said apparatus in a direction substantially parallel with, or substantially coincident with, said first axial direction. 
   
   
       19 . An apparatus as claimed in  claim 1 , wherein said fluid inlet is provided at or adjacent the in use lower end of the apparatus. 
   
   
       20 . An apparatus as claimed in  claim 1 , wherein said body is substantially cylindrical in shape. 
   
   
       21 . An apparatus as claimed in  claim 1 , wherein said apparatus is in fluid communication with a storage tank having an in use upper portion and an in use lower portion, wherein said fluid outlet is provided at the in use top end of the apparatus and is in fluid communication with said in-use upper portion of said tank, and said fluid inlet is provided at or adjacent a lower end of said apparatus and is in fluid communication with said in-use lower portion of said tank, said fluid communication being substantially unrestricted to allow thermosyphonic flow of fluid between the storage tank and the apparatus during use. 
   
   
       22 . An apparatus as claimed in  claim 21 , wherein said apparatus is located externally of the tank, preferably adjacent a side of the tank. 
   
   
       23 . An apparatus as claimed in  claim 22 , connected to said storage tank by a fluid conduit including a delivery section for delivering fluid into said upper portion of the tank, wherein said delivery section is arranged to deliver said fluid from above the tank in use, preferably through the top of the tank. 
   
   
       24 . An apparatus as claimed in  claim 23 , wherein said delivery section extends from the top of the storage tank in a substantially vertical direction in use. 
   
   
       25 . An apparatus as claimed in  claim 22 , connected to said storage tank by a fluid conduit including a section through which fluid is drawn in use from the top of the apparatus, said drawing section extending from said apparatus in a substantially vertical direction in use. 
   
   
       26 . An apparatus as claimed in  claim 21 , wherein the apparatus is provided internally of the tank. 
   
   
       27 . An apparatus as claimed in  claim 26 , wherein said fluid outlet opens onto said upper portion of the tank and said fluid inlet opens onto said lower portion of the tank. 
   
   
       28 . An apparatus as claimed in  claim 26 , a fluid conduit being connected to the upper portion of the tank, preferably at the top of the tank, for drawing fluid from the upper portion of the tank, and wherein said fluid outlet is substantially aligned with said fluid conduit. 
   
   
       29 . An apparatus as claimed in  claim 1 , wherein said flow inlet and said return outlet are connected to an apparatus for heating said heating medium, preferably a solar energy heating apparatus, or other renewable energy heating apparatus. 
   
   
       30 . A heating system comprising a storage tank for a fluid; and an apparatus for heating said fluid, said heating apparatus including a chamber for containing a quantity of said fluid and means for heating the fluid in said chamber, wherein said apparatus has a fluid outlet provided at the in use top end of the chamber and which is in fluid communication with an in use upper portion of said tank, and a fluid inlet provided at or adjacent a lower end of said chamber and which is in fluid communication with an in-use lower portion of said tank, said fluid communication being substantially unrestricted to allow thermosyphonic flow of fluid between the storage tank and the apparatus during use. 
   
   
       31 . A system as claimed in  claim 30 , wherein said apparatus is located externally of the tank, preferably adjacent a side of the tank. 
   
   
       32 . A system as claimed in  claim 31 , wherein the apparatus is connected to said storage tank by a fluid conduit including a delivery section for delivering fluid into said upper portion of the tank, wherein said delivery section is arranged to deliver said fluid from above the tank in use, preferably through the top of the tank. 
   
   
       33 . A system as claimed in  claim 32 , wherein said delivery section extends from the top of the storage tank in a substantially vertical direction in use. 
   
   
       34 . A system as claimed in  claim 31 , wherein the apparatus is connected to said storage tank by a fluid conduit including a section through which fluid is drawn in use from the top of the apparatus, said drawing section extending from said apparatus in a substantially vertical direction in use. 
   
   
       35 . A system as claimed in  claim 30 , wherein the apparatus is provided internally of the tank. 
   
   
       36 . A system as claimed in  claim 35 , wherein said fluid outlet opens onto said upper portion of the tank and said fluid inlet opens onto said lower portion of the tank. 
   
   
       37 . A system as claimed in  claim 35 , comprising a fluid conduit connected to the upper portion of the tank, preferably at the top of the tank, for drawing fluid from the upper portion of the tank, and wherein said fluid outlet is substantially aligned with said fluid conduit.