Heat exchanger for heating water

Abstract

Aspects of the invention provide a heat exchanger including a shell at least partially defining an interior region; a burner positioned to deliver combustion gases into the interior region; and a plurality of tubes configured to circulate water therein, the plurality of tubes extending through the interior region. The plurality of tubes further including an inner set of tubes and an outer set of tubes, the inner set of tubes being closer to the burner than the outer set of tubes. The inner set of tubes and the outer set of tubes being positioned adjacent to one another such that the outer set of tubes is staggered from the inner set of tubes and tubes of the outer set of tubes are adjacent to tubes of the inner set of tubes. Additionally, baffle segments are annularly positioned in the interior region adjacent the plurality of tubes. Adjacent baffle segments defining gaps for the flow of the combustion gases.

What is claimed: 
     
         1 . A heat exchanger for heating water, the heat exchanger comprising:
 a shell at least partially defining an interior region;   a burner positioned to deliver combustion gases into the interior region;   a fuel supply configured to supply fuel to the burner;   a controller configured to control the fuel supply;   a plurality of tubes configured to circulate water therein, the plurality of tubes extending through the interior region, the plurality of tubes including an inner set of tubes and an outer set of tubes, the inner set of tubes being closer to the burner than the outer set of tubes; baffle segments positioned in the interior region adjacent the outer set of tubes, adjacent baffle segments defining gaps for the flow of the combustion gases outwardly relative to the outer set of tubes; and   a condensate drain positioned to receive condensate from the interior region;   wherein the heat exchanger is configurable to operate in a condensing mode in which moisture condenses from the combustion gases or a non-condensing mode in which moisture does not condense from the combustion gases;   wherein the condensate drain is coupled to receive condensate from the interior region when the heat exchanger is operated in the condensing mode; and   wherein the heat exchanger is configurable to operate in the condensing mode or in the non-condensing mode by adjusting the controller.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the controller is configurable to:
 during the condensing mode, operate the heat exchanger using a modulating process, and   during the non-condensing mode, operate the heat exchanger using a single stage process.   
     
     
         3 . The heat exchanger of  claim 1 , wherein the baffle segments extend between two or more of the outer set of tubes. 
     
     
         4 . The heat exchanger of  claim 1 , wherein when the heat exchanger is operating in a non-condensing mode, the controller activates or deactivates the fuel supply to provide a set amount of fuel mixture to the burner. 
     
     
         5 . The heat exchanger of  claim 4 , wherein the controller modulates an amount of the fuel or fuel mixture provided by the fuel supply to the burner when the heat exchanger is operating in the condensing mode. 
     
     
         6 . The heat exchanger of  claim 1 , wherein the heat exchanger is configurable to operate in the condensing mode or in the non-condensing mode by adjusting the controller, by adjusting the gaps defined between adjacent baffle segments, or by adjusting the controller and adjusting the gaps defined between adjacent baffle segments. 
     
     
         7 . A heat exchanger for heating water, the heat exchanger comprising:
 a non-circular shell at least partially defining an interior region;   a burner positioned to deliver combustion gases into the interior region;   a plurality of tubes configured to circulate water therein, the plurality of tubes extending through the interior region, the plurality of tubes including an inner set of tubes and an outer set of tubes, the inner set of tubes being closer to the burner than the outer set of tubes;   baffle segments positioned in the interior region adjacent the outer set of tubes, adjacent baffle segments defining gaps for the flow of the combustion gases outwardly relative to the outer set of tubes.   
     
     
         8 . The heat exchanger of  claim 7 , wherein the non-circular shell defines an oval interior region having a top region and a bottom region. 
     
     
         9 . The heat exchanger of  claim 8 , wherein the plurality of tubes extends vertically through the oval interior region from the bottom region to the top region. 
     
     
         10 . The heat exchanger of  claim 7 , wherein each of the plurality of tubes receives approximately an equal amount of heat loading from the combustion gases within the oval interior region. 
     
     
         11 . A heat exchanger for heating water, the heat exchanger comprising:
 a shell at least partially defining an interior region;   a burner positioned to deliver combustion gases into the interior region;   a plurality of tubes configured to circulate water therein, the plurality of tubes extending through the interior region, the plurality of tubes including an inner set of tubes and an outer set of tubes, the inner set of tubes being closer to the burner than the outer set of tubes;   the inner set of tubes and the outer set of tubes being positioned adjacent to one another such that the outer set of tubes is staggered from the inner set of tubes and tubes of the outer set of tubes are adjacent to tubes of the inner set of tubes; and   baffle segments annularly positioned in the interior region adjacent the plurality of tubes, adjacent baffle segments defining gaps for the flow of the combustion gases.   
     
     
         12 . The heat exchanger of  claim 11 , wherein the plurality of tubes forms a single annular row of tubes. 
     
     
         13 . A heat exchanger for heating water, the heat exchanger comprising:
 a shell at least partially defining an interior region;   a burner positioned to deliver combustion gases into the interior region;   a plurality of tubes configured to circulate water therein, the plurality of tubes extending through the interior region, the plurality of tubes including an inner set of tubes and an outer set of tubes, the inner set of tubes being closer to the burner than the outer set of tubes;   baffle segments annularly positioned in the interior region adjacent the outer set of tubes, adjacent baffle segments defining gaps for the flow of the combustion gases outwardly relative to the outer set of tubes;   a tube sheet positioned at an end region of the shell, the tube sheet being coupled to the plurality of tubes; and   a header coupled to the shell, the header and the tube sheet together defining a cavity between the header and the tube sheet, the tube sheet further defining an inner set of apertures in water flow communication with the inner set of tubes and defining an outer set of apertures in water flow communication with the outer set of tubes.   
     
     
         14 . The heat exchanger of  claim 13 , wherein the header further includes barriers extending between apertures of the outer set of apertures and apertures of the inner set of apertures. 
     
     
         15 . The heat exchanger of  claim 14 , wherein each of the barriers is positioned tangential to one of the apertures of the outer set of apertures and tangential to one of the apertures of the inner set of apertures. 
     
     
         16 . The heat exchanger of  claim 13 , wherein the barriers are deformed between the header and the tube sheet, upon affixing the header to the shell. 
     
     
         17 . The heat exchanger of  claim 13 , wherein the header is formed of a single unitary material. 
     
     
         18 . The heat exchanger of  claim 1 , wherein the controller is integrated into the fuel supply. 
     
     
         19 . The heat exchanger of  claim 1 , wherein the controller is separate from and coupled to the fuel supply.