Combustion heating apparatus

Abstract

A domestic boiler preheater includes a flue box including a combustion gas inlet to receive hot combustion gas from a boiler, and a combustion air inlet to receive air for combustion in a boiler. The preheater includes a condenser including a mains cold water inlet and a mains water outlet arranged such that mains water flows through the condenser prior to being supplied to a boiler combustion chamber. The condenser includes a central heating water return and a central heating water flow outlet arranged such that central heating water flows through the condenser prior to being supplied to the boiler combustion chamber. The condenser includes connections that enable the condenser to be connected to preheated fluid supply pipework from a source of preheated fluid, the preheated fluid including fluid heated by heat from at least one of the combustion gas and a renewable energy source.

What is claimed is: 
     
         1 . A combustion heating apparatus preheater comprising:
 an assembly comprising at least one of a flue box, a flue pipe, and a combustion chamber, wherein the assembly further comprises a combustion chamber gas heat exchanger arranged in use to transfer heat from a combustion gas to inlet combustion air, the heat exchanger comprising an array of heat rods which are filled with fluid or are solid metal rods, and in the case of the fluid filled rods, in use, these are arranged to transfer heat from the gas into the fluid, heat being transferred from the fluid to the inlet combustion air.   
     
     
         2 . The apparatus as claimed in  claim 1  in which where the heat rods are provided in a flue pipe, said rods arranged to extend transversely of an internal space of the flue pipe. 
     
     
         3 . The apparatus as claimed in  claim 1  in which the heat rods comprise one or more heat exchange fins. 
     
     
         4 . The apparatus as claimed in  claim 2  in which the heat rods comprise one or more heat exchange fins. 
     
     
         5 . The apparatus as claimed in  claim 1  which comprises a plurality of spaced apart heat rods. 
     
     
         6 . The apparatus as claimed in  claim 5  in which where the heat rods are provided in a flue pipe, they are spaced longitudinally of the flue pipe. 
     
     
         7 . The apparatus as claimed in  claim 1  in which the pre-heater is module which is arranged to be connected to a flue pipe, either at the time of initial installation or commission of the apparatus, or as a retro-fittable module to the flue pipe. 
     
     
         8 . The apparatus as claimed in  claim 1  which is for use with a boiler for heating liquid of at least one of a central heating system and a heated water supply system. 
     
     
         9 . The apparatus as claimed in  claim 1  which is a gas combustion boiler preheater. 
     
     
         10 . A combustion heating apparatus preheater comprising:
 a flue box comprising:
 a combustion gas inlet that receives hot combustion gas from a boiler; and 
 a combustion air inlet that receives air for combustion in said boiler; 
   a condenser comprising:
 a mains cold water inlet; 
 a mains water outlet, wherein said mains cold water inlet and said mains water outlet are arranged such that mains water flows through said condenser prior to being supplied to a boiler combustion chamber; 
 a central heating water return; 
 a central heating water flow outlet, wherein said central heating water return and said central heating water flow outlet are arranged such that central heating water flows through said condenser prior to being supplied to said boiler combustion chamber; and 
 a plurality of connections that enable said condenser to be connected to preheated fluid supply pipework from a source of preheated fluid, wherein said preheated fluid comprises fluid heated by heat from any of combustion gas or a renewable energy source; 
   a combustion gas heat exchanger operative to transfer heat from the combustion gas flowing through the combustion gas inlet to the combustion air flowing through the combustion air inlet such that the combustion air is preheated prior to entering the boiler,   wherein said condenser transfers heat from said preheated fluid to at least one of mains cold water from said mains cold water inlet, or central heating water from said central heating water return in order to preheat the mains or central heating water prior to entering said boiler combustion chamber, wherein the combustion gas heat exchanger comprises at least one heat rod filled with a fluid, wherein heat is transferred from the combustion gas into the fluid, and wherein heat is transferred from the vaporized fluid to the inlet combustion air by subsequently condensing the fluid.   
     
     
         11 . The preheater as claimed in  claim 10 , wherein said combustion gas heat exchanger is operative to heat the preheated fluid prior to the preheated fluid entering the condenser. 
     
     
         12 . The preheater as claimed in  claim 10 , wherein the combustion gas heat exchanger comprises any of (i) part of the flue box, and (ii) part of a separate flue pipe. 
     
     
         13 . The preheater as claimed in  claim 10 , wherein the combustion gas heat exchanger is provided at the flue box. 
     
     
         14 . The preheater as claimed in  claim 10 , further comprising an array of parallel heat rods. 
     
     
         15 . The preheater as claimed in  claim 14 , wherein the combustion gas heat exchanger is provided in the separate flue pipe. 
     
     
         16 . The preheater as claimed in  claim 14 , further comprising an array of heat rods spaced along a longitudinal axis of the flue pipe. 
     
     
         17 . The preheater as claimed in  claim 10 , wherein the condenser comprises an array of tubes some of which are connected between the mains cold water inlet and the mains water outlet so that mains water passes along the tubes, and some of which are connected between the central heating water return and the central heating water flow outlet so that central heating water passes along the tubes, and wherein the condenser further comprises a heat exchange coil arranged with the tubes to transfer heat from the preheated fluid to the water in the tubes. 
     
     
         18 . The preheater as claimed in  claim 10 , wherein the renewable energy source is arranged to directly heat the preheated fluid. 
     
     
         19 . The preheater as claimed in  claim 10 , wherein the renewable energy source is arranged to indirectly heat the preheated fluid. 
     
     
         20 . The preheater as claimed in  claim 10 , wherein the combustion gas heat exchanger comprises at least one heat rod comprising a substantially solid metal rod.