Patent ID: 7302916

Claim:
A condensation heat exchanger adapted to interface with a gas or fuel-oil burner, the condensation heat exchanger comprising two coaxial tube bundles placed end-to-end, one of which acts as primary exchanger and the other of which acts as secondary exchanger, each of these bundles comprising at least one of a tube or of a group of tubes arranged end-to-end, forming a helical coil, in which the wall of the tube(s) is produced from a material that is a good conductor of heat and has a flattened, oval cross section, the major axis of which is perpendicular or approximately perpendicular to the axis of the helix, wherein the width of the gap separating two adjacent turns is constant and smaller than the thickness of said cross section, said bundles being mounted securely inside a gas-impermeable jacket, the condensation heat exchanger further comprising a device adapted to circulate at least one fluid to be heated inside the tube(s) forming said bundles, said jacket having a burnt-gas-evacuation sleeve, the exchanger being arranged such that hot gases generated by the burner flow radially, or approximately radially, through said bundles, passing through gaps separating turns of the bundles, a deflection plate being interposed between these two bundles and arranged in such a manner that hot gases generated by the burner first flow through the primary exchanger, flowing through the gaps separating its turns from the inside to the outside, then through the secondary exchanger, flowing through gaps separating its turns from the outside to the inside, after which the hot gasses are evacuated to the outside via said sleeve, wherein said jacket has a wall portion having the configuration of a compartment and the condensation heat exchanger is provided with an additional gas/air heat exchanger/recuperator that is inserted inside said compartment and is adapted for recovering some heat conveyed by the hot gases circulating between the secondary exchanger and the exit sleeve and transferring heat to air captured outside the exchanger, the condensation exchanger further including a device adapted to transfer the air heated by the additional gas/air heat exchanger/recuperator to the entrance of said burner.