Spiral finned coil condensing heat exchanger

Abstract

A heat exchanger for supplying heat includes a housing, a bundle of helical fin-coil tubes, and a flue channel. The housing includes a burner, a water inlet, a water outlet and a flue gas outlet. The burner is disposed on a top portion of the housing and connected to an air/gas mixture unit. The bundle of helical fin-tube coils is disposed tightly, circularly, and coaxially around the burner. The flue channel is disposed below the burner and is formed by a plurality of helical fin-tube coils. A flow of flue gas vents from the flue channel to the flue gas outlet. The water inlet is connected to the plurality of helical fin-tube coils which forms the flue channel below the burner. The plurality of helical fin-tube coils below the burner are connected to the bundle of helical fin-tube coils. The bundle of helical fin-tube coils are connected to the water outlet.

What is claimed is: 
     
         1 . A heat exchanger for supplying heat, comprising:
 a housing includes:
 a burner; 
 a water inlet; 
 a water outlet; and 
 a flue gas outlet; 
   the burner is disposed on a top portion of the housing and connected to an air/gas mixture unit;   a bundle of helical fin-tube coils are disposed tightly, circularly, and coaxially around the burner;   a flue channel is disposed below the burner, the flue channel being formed by a plurality of helical fin-tube coils, wherein a flow of flue gas vents from the flue channel to the flue gas outlet;   the water inlet is connected to the plurality of h be coils which forms the flue channel below the burner;   the plurality of helical fin-tube coils below the burner are connected to the bundle of helical fin-tube coils; and   the bundle of helical fin-tube coif are connected to the water outlet.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein a plurality of fins on the bundle of helical fin-tube coils are bent at a predetermined angle and respective surfaces of the plurality of fins are parallel or at a predetermined angle. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the plurality of helical fin-tube coils include pairs of helical fin-tube coils assembled together with corresponding helical fin-tube coils that are coiled in the opposite orientation. 
     
     
         4 . The heat exchanger according to  claim 1 , further comprising:
 a plurality of outer flue baffles installed around the bundle of the helical fin-tube coils.   
     
     
         5 . The heat exchanger according to  claim 4 , wherein the outer flue baffle include a “V” type cross section with a radiused portion configured to mate with ones of the fins of the bundle of helical fin-tube coils and wherein the interfaces of the bundle of helical fin-tube coils is disposed in a circle that are staggered with the openings between the plurality of outer flue baffles. 
     
     
         6 . The heat exchanger according to  claim 1 , further comprising:
 an inner flue baffle disposed below the burner is installed inside the plurality of helical fin-tube coils which formed the flue channel.   
     
     
         7 . The heat exchanger according to  claim 6 , wherein the inner flue baffle includes a plurality of holes or slots, the inner cylindrical flue baffle being placed inside the flue channel adjacent to the bundle of helical fin-tube coils and wherein a plurality of inside interfaces of the helical fin-tube coils are staggered with the openings of the inner flue baffle. 
     
     
         8 . The heat exchanger according to  claim 1 , further comprising:
 an air pre-heater disposed inside the flue channel, wherein the air pre-heater is located inside and along the flue channel and connected with an air inlet, the flue exhaust being a 4-way connector, wherein the flue exhaust is disposed on a top portion of the heat exchanger; and   a condensate outlet disposed at a bottom portion of the heat exchanger and the air inlet being disposed in a middle portion of the heat exchanger.   
     
     
         9 . The heat exchanger according to  claim 8 , wherein the air pre-heater disposed inside the flue channel includes one or more cuboidal or cylindrical air inlet tubes. 
     
     
         10 . A heat exchanger comprising:
 a housing having a flue gas outlet and a water outlet;   a burner disposed in a lower portion of the housing;   a bundle of the helical fin-tube coils are mounted adjacent to each other around the burner;   a flue gas channel is disposed above the burner, the flue gas channel being formed by a plurality of helical fin-tube coils, wherein a flow of flue gas is vented from the flue gas channel to the flue gas outlet;   a water inlet connected to the plurality of helical fin-tube coils, wherein the plurality of helical fin-tube coils are connected to the bundle of helical fin-tube coils which are then connected to the water outlet.