Abstract:
A heat transfer panel, or multiple panels, utilized to absorbed heat from the turbine exhaust gas as part of the Rankin cycle which simultaneously distributes the exhaust gas through the waste heat boiler. The panel varies the gas flow characteristics across a transverse and longitudinal plane, thereby eliminating the need for a separate flow distribution device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/184,364 filed Jun. 25, 2015, which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention in general relates to flow distribution devices within waste heat boilers. 
       BACKGROUND OF THE INVENTION 
       [0003]    A duct burner or SCR (Selective Catalytic Reduction Reactor) of a waste heat boiler will receive heated exhaust from a combustion turbine, or other source, and use the heat from that exhaust to generate steam. Heat transfer tubes are located downstream from the exhaust from a combustion turbine. The heat transfer tubes employ extended surfaces to facilitate heat transfer from the gas turbine exhaust to the boiler working fluid.  FIGS. 1, 2, and 3  represent typical tube surfaces.  FIG. 1  depicts a typical tube panel.  FIG. 1  is vertical view of a typical tube panel which is disposed adjacent to the exhaust port for a combustion turbine. One of the functions of the typical tube panel is to adjust the velocity profile of the exhaust gas exiting the exhaust port of the combustion turbine.  FIG. 2  depicts a typical tube surface.  FIG. 3  depicts a close-up of a typical tube surface. In some embodiments, as depicted in  FIG. 2  and  FIG. 3 , the extended surface or fins may be secured about or be integral to the perimeter of a heat transfer tube. In some embodiments, heat transfer tubes located proximate to a duct burner or SCR for a waste heat boiler as shown in  FIGS. 2 and 3  are exposed to the heated exhaust from the combustion turbine and use the heat from that exhaust to generate steam. The heat transfer tubes located downstream from the exhaust for a combustion turbine employ extended surfaces to facilitate heat transfer from the gas turbine exhaust to the boiler working fluid. Generally, the heat transfer tubes located proximate to a duct burner or SCR for a waste heat boiler will have an outside diameter between 1.25 and 2.25 inches. 
         [0004]      FIG. 4  is a horizontal view directed at the exhaust port for a combustion turbine. Exterior and proximate to the exhaust port for the combustion turbine is located a turning vane. The elevation, angled orientation, or rotational orientation/position of the turning vane, or sections or portions of the turning vane, relative to the exhaust port for the combustion turbine, will affect the direction and/or velocity profile of the exhaust gas, which will pass through the chamber and which may ultimately enter into a critical component within a Heat Recovery Steam Generator. 
         [0005]      FIG. 5  shows a horizontal view directed at the exhaust port for the combustion turbine where a perforated plate is disposed over the exhaust port. The perforated plate has numerous sections having the same or different configurations. Different configurations of plates may be used to adjust the velocity profile of the exhaust gas exiting the exhaust port of the combustion turbine. The configuration of the perforated plates will affect the direction and/or velocity profile of the exhaust gas, which will pass through the chamber and which may ultimately enter into a critical component within a Heat Recovery Steam Generator. 
         [0006]    In some configurations, the turbine exhaust gas entering the waste heat boiler enters the boiler non-uniformly across the transverse internal area of the waste heat boiler. Exhaust gas velocity exiting the combustion or gas turbine may pass at a velocity of typically 80-100 ft/sec and the localized velocity may sometimes be as high as 250 ft/sec depending on the make and model of the gas or combustion turbine. Also, the exhaust gas exiting the combustion turbine may exit the combustion turbine at a gas swirl angle which may vary depending on make and model of the turbine. The exhaust gas swirl angle may occur at an angle of approximately 20 degrees clockwise and/or 20 degrees counterclockwise. In some embodiments, various components such as a duct burner will require an even flow distribution of heated exhaust gas to function or operate within normal parameters. 
         [0007]    At the present there are two general methods for attempting to achieve a satisfactory flow distribution for exhaust gas exiting the exhaust port of the combustion turbine prior to entry into a waste heat boiler or other critical component. As seen in  FIG. 1 , flow directing vanes can be installed in an upstream location. The vanes redistribute the exhaust gas flow. The use of vanes to redistribute the exhaust gas flow have fallen out of favor in recent years because the velocity profile entering the vanes is only approximately known at best; and the velocity profile downstream may not be sufficiently uniform. Additionally, or in an alternative, during use, the vanes are uncooled and are subject to high temperatures and high levels of turbulence. In the past the reliability and/or durability of the vanes has been an issue. 
         [0008]    As seen in  FIG. 5 , perforated plates are the most common way of smoothing the velocity profile for exhaust gas exiting the exhaust port of the combustion turbine. The perforated plate consists of a flat plate with zones of open area creating a variable pressure drop which redistributes the exhaust flow. Perforated plates are a less than optimum method of distributing flow because the perforated plates are subject to high temperatures, and the pressure drop across the plate reduces efficiency, is difficult to regulate, and is inconsistent. If a perforated plate is located upstream, then the perforated plate is subject to high turbulence which may cause the perforated plate to become a high maintenance item or component. Further, perforated plates add pressure drop to the system, thereby reducing the system efficiency. 
         [0009]    The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists. 
         [0010]    All U.S. patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety. 
         [0011]    Without limiting the scope of the invention, a brief description of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below. 
         [0012]    A brief abstract of the technical disclosure in the specification is provided for the purposes of complying with 37 C.F.R. §1.72. 
       GENERAL DESCRIPTION OF THE INVENTION 
       [0013]    As an alternative to specific flow distribution devices, the design and installation of a heating surface having a sufficient number of rows and/or configuration of heat transfer tubes adequately regulates the resulting pressure drop and provides an acceptable distribution/redistribution of the exhaust gas exiting the exhaust port of the combustion turbine. 
         [0014]    In some embodiments, a heat transfer panel, comprised of a plurality of vertically or horizontally orientated heat transfer tubes, or multiple panels of heat transfer tubes, are utilized to absorb heat from the turbine exhaust gas as part of the Rankin cycle, which simultaneously distributes the exhaust gas through the duct burner and/or waste heat boiler. 
         [0015]    In some embodiments, a heat transfer panel, or multiple panels vary the exhaust gas flow characteristics from a gas or combustion turbine across a transverse and longitudinal plane, thereby eliminating the need for a separate flow distribution device. The heat transfer panel, or multiple panels may have varied extended surface characteristics disposed along the length of the heat transfer tubes. Alternatively, the heat transfer tube to heat transfer tube separation or relative spacing distance in either the transverse or longitudinal direction may be modified to achieve the differential flow characteristics required to redistribute the exhaust gas flow across a transverse plane. One alternative in addition to heat transfer of this panel, may be to create uniform gas flow and a desired velocity profile for the exhaust gas. 
         [0016]    In some embodiments there may be a small number of rows of heat absorbing heat transfer tubes upstream of the duct burner or other critical component. The pressure drop across the rows of heat absorbing tubes improves the velocity profile of the exhaust gas flow, but the velocity profile is usually not sufficient to satisfy the desired velocity profile at the duct burner or other critical component. Note that a large tube bank upstream of the duct burner or other critical component would sufficiently improve the velocity profile, but thermal design constraints typically dictate the use of a small tube bank upstream of the duct burner or other critical component. 
         [0017]    In some embodiments a panel or multiple panels of heat transfer tubes may be utilized in either original design or retrofit applications between a gas or combustion turbine and a duct burner or other critical component. 
         [0018]    In some of the embodiments, each of the panels or multiple panels of heat transfer tubes will include fins. In some embodiments, the varying of the fin density and/or heat transfer tube spacing (as another pressure drop influencing parameter) where the heat transfer tubes are located upstream from the duct burner or other critical component, will function in a manner similar to a perforated plate of varying porosity. The use of panels or multiple panels of heat transfer tubes having fins, and the spacing of the heat transfer tubes relative to each other, may provide a tremendous performance advantage over a perforated plate. The use of panels or multiple panels of heat transfer tubes having fins and the spacing of the heat transfer tubes relative to each other may eliminate additional pressure drop through the system. The heat transfer tube bank pressure drop is normal and expected in the system. In addition, the expense of a perforated plate or vane assembly is avoided. Further the tube banks are cooled and robust and no additional maintenance cost is required. 
         [0019]    In a first alternative embodiment, a heat transfer device is disclosed comprising: a plurality of tubes, the plurality of tubes being disposed in rows of tubes, the rows of tubes forming a tube panel; and a plurality of fins engaged to each of the plurality of tubes; wherein the plurality of rows of tubes are vertically organized into a least a first pressure drop zone and a second pressure drop zone. 
         [0020]    In a second alternative embodiment according to the first alternative embodiment, the plurality of tubes within at least one of the rows of tubes are uniformly spaced relative to another of the tubes within the at least one row of tube. 
         [0021]    In a third alternative embodiment according to the first alternative embodiment, the plurality of tubes within at least one of the rows of tubes are irregularly spaced relative to another of the tubes within the at least one row of tubes. 
         [0022]    In a fourth alternative embodiment according to the first alternative embodiment, the plurality of tubes within the first pressure drop zone are separated from each other a first distance, and the plurality of tubes within the second pressure drop zone are separated from each other a second distance, the first distance having a different dimension as compared to the second distance. 
         [0023]    In a fifth alternative embodiment according to the first alternative embodiment, a first number of fins are engaged to each of the plurality of tubes in the first pressure drop zone and a second number of fins are engaged to each of the plurality of tubes in the second pressure drop zone, the first number of fins being different from the second number of fins. 
         [0024]    In a sixth alternative embodiment according to the second alternative embodiment, the spacing between adjacent tubes in a row of tubes is identified as a transverse tube spacing having a dimension, the spacing being constructed and arranged to be variable and to modify a gas flow characteristic of the heat transfer device to achieve a desired flow distribution. 
         [0025]    In a seventh alternative embodiment according to the first alternative embodiment, the tube panel is constructed and arranged to act as a heat transfer surface and is constructed and arranged to distribute turbulent combustion turbine exhaust flow. 
         [0026]    In an eighth alternative embodiment according to the fifth alternative embodiment, the first number of fins and the second number of fins are constructed and arranged to establish a desired exhaust gas flow distribution downstream from the tube panel. 
         [0027]    In a ninth alternative embodiment according to the first alternative embodiment, the tube panel comprises a panel upper header and a panel lower header, each of the panel upper header and the panel lower header having a header nozzle. 
         [0028]    In a tenth alternative embodiment according to the first alternative embodiment, the heat transfer device further comprises tube ties, wherein the tube ties secure the plurality of tubes into the first pressure drop zone and the second pressure drop zone. 
         [0029]    In an eleventh alternative embodiment according to the first alternative embodiment, at least one of the plurality of rows of tubes are vertically organized into an intermediate pressure drop zone. 
         [0030]    In a twelfth alternative embodiment according to the eleventh alternative embodiment, the plurality of tubes within the intermediate pressure drop zone are separated from each other a third distance, the third distance being smaller than the second distance and the third distance being larger than the first distance. 
         [0031]    In a thirteenth alternative embodiment according to the twelfth alternative embodiment, a third number of fins is engaged to each of the plurality of tubes in the intermediate pressure drop zone, the third number of fins being larger than the second number of fins, and the third number of fins being smaller than the first number of fins. 
         [0032]    In a fourteenth alternative embodiment according to the thirteenth alternative embodiment, the first number of fins, the third number of fins, and the second number of fins are constructed and arranged to establish a desired exhaust gas flow distribution downstream from the tube panel. 
         [0033]    In another alternative embodiment, a tube panel, or multiple panels will act as both a heat transfer surface utilized in a waste heat boiler as part of the Rankin cycle, as well as a device to distribute turbulent combustion turbine exhaust flow for downstream components which require uniform gas flow. 
         [0034]    In another alternative embodiment, a tube panel, or multiple panels have extended surfaces, where the extended surfaces along the length of the tubes is varied in order to achieve a desired exhaust gas flow distribution. 
         [0035]    In another alternative embodiment, a tube panel, or multiple panels include a longitudinal tube spacing between the tubes which is varied to modify the gas flow characteristics to achieve desired flow distribution. 
         [0036]    These and other embodiments which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for further understanding of the invention, its advantages and objectives obtained by its use, reference should be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there is illustrated and described embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]      FIG. 1  depicts a typical tube panel of the prior art; 
           [0038]      FIG. 2  depicts a typical tube surface of the prior art; 
           [0039]      FIG. 3  depicts a close-up of a typical tube surface of  FIG. 2  of the prior art; 
           [0040]      FIG. 4  shows a turning vane proximate to an exhaust port of a combustion turbine of the prior art; 
           [0041]      FIG. 5  shows a horizontal view of a exhaust port of a combustion turbine having a perforated plate disposed over the exhaust port of the prior art; 
           [0042]      FIG. 6  depicts a system schematic of one alternative embodiment of a heating system including a perforated plate of the prior art; 
           [0043]      FIG. 7  depicts a system schematic of one alternative embodiment of a heating system including a turning vane of the prior art; 
           [0044]      FIG. 8  depicts a system schematic of one alternative embodiment of the invention having a dual function heat transfer surface; 
           [0045]      FIG. 9  depicts a front view of one alternative embodiment of the invention having a dual function heat transfer surface; 
           [0046]      FIG. 10  depicts a detail top view of one alternative embodiment of the invention having a low pressure drop tube configuration; 
           [0047]      FIG. 11  depicts a detail top view of one alternative embodiment of the invention having an intermediate pressure drop tube configuration; 
           [0048]      FIG. 12  depicts a detail top view of one alternative embodiment of the invention having a high pressure drop tube configuration; 
           [0049]      FIG. 13  depicts a detail top view of one alternative embodiment of the invention having a mixed pressure drop tube configuration; 
           [0050]      FIG. 14  depicts a detail partial top view of one alternative embodiment of the invention having a low pressure drop tube configuration; 
           [0051]      FIG. 15  depicts a detail partial top view of one alternative embodiment of the invention having and intermediate pressure drop tube configuration; 
           [0052]      FIG. 16  depicts a detail partial top view of one alternative embodiment of the invention having a high pressure drop tube configuration; 
           [0053]      FIG. 17 a    depicts a detail partial top view of one alternative embodiment of a fin configuration for a tube of the invention; 
           [0054]      FIG. 17 b    depicts a detail partial side view of one alternative embodiment of a fin as used on a tube in one embodiment of the invention; 
           [0055]      FIG. 18  depicts a detail partial side view of one alternative embodiment of fin configurations for tubes within a high, intermediate, low, and minimum pressure drop zones of the invention; and 
           [0056]      FIG. 19  depicts a partial isometric view of one alternative embodiment of a bundle of dual function heat surfaces of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0057]    In at least one embodiment of the present invention as depicted in  FIGS. 9, 10, 11, 12, 13, and 18  a tube panel  10  is shown. Tube panel  10  may be formed of an upper header  1  and lower header  5  with interconnecting inlet piping  12  and outlet piping  14  having header nozzles  2 . In at least one embodiment, the tube panel  10  includes any desired number of varying pressure drop areas which will modify the gas flow characteristics of exhaust gas exiting the exhaust port of a combustion turbine. The varying pressure drop areas may be disposed vertically relative to each other in any desired combination or positional location. 
         [0058]    In some embodiments the modification of the gas flow characteristics of exhaust gas exiting the exhaust port of a combustion turbine will be achieved by varying the heat transfer tube placement and/or the tube fin  24  density. In a high pressure drop finning configuration five to six fins  24  may be used per inch. A high pressure drop finning configuration is identified by reference numeral  9 . A high pressure drop finning configuration may be provided along any desired portion, section or length of a heat transfer tube  16 , or along the entire length of a heat transfer tube  16 . 
         [0059]    In an intermediate pressure drop configuration four to five fins  24  may be used per inch. An intermediate pressure drop finning configuration is identified by reference numeral  8 . An intermediate pressure drop finning configuration  8  may be provided along any desired portion, section or length of a heat transfer tube  16 , or along the entire length of a heat transfer tube  16 , in order to establish a moderate pressure drop at a desired location. 
         [0060]    In a low pressure drop configuration two to four fins  24  may be used per inch. A low pressure drop finning configuration is identified by reference numeral  7 . A low pressure drop finning configuration  7  may be provided along any desired portion, section or length of a heat transfer tube  16 , or along the entire length of a heat transfer tube  16 , in order to establish a lower pressure drop at a desired location. 
         [0061]    In some embodiments, bare tubes  6  having no fins  24  per inch may provide a minimal pressure drop. ( FIG. 18 ) The high, intermediate, low or minimal fin arrangements  9 ,  8 ,  7 , and  6  respectively, for a desired pressure drop may be used in any combination to regulate the desired flow characteristics for exhaust gas exiting a combustion turbine. 
         [0062]    In some embodiments, tube restraints or tube ties  4  may be used to modify or vary the spacing between adjacent heat transfer tubes  16 , or heat transfer tubes  16  located proximate to each other longitudinally, or disposed along the length of the tube panel  10 , creating a high pressure drop zone referred to generally by reference numeral  18  in  FIG. 12 , an intermediate pressure drop zone referred to generally by reference numeral  20  in  FIG. 11 , and a low pressure drop zone referred to generally by reference numeral  22  in  FIG. 10 . Alternatively, in some embodiments, the pressure drop characteristics may also be varied across a single panel upper header  1  or a single panel lower header  5  as shown in  FIG. 13 . 
         [0063]    In at least one embodiment as depicted in  FIG. 6  a typical heat transfer system including a perforated plate  26  is shown. As may be seen in  FIG. 6  the heat transfer system includes a low pressure steam drum  32  having a high pressure feed water inlet  28  where the feed water enters into an economizer. The economizer is in fluid flow relationship with a low pressure evaporator. Fluid then flows to the high pressure steam drum  36  which includes a high pressure economizer, a high pressure evaporator, and a high pressure super heater. Fluid may then flow into a deaerator  44 , where fluid leaves the deaerator  44  as high pressure steam. Adjacent to the deaerator  44  is located a burner  46  which has a velocity profile that is +−10% of the flow velocity. A perforated plate  26  may be positioned exterior to the burner  46  to be exposed to exhaust gases. The perforated plate  26  may have various settings including 30% open, 50% open, and/or 60% open. As seen in  FIG. 6  a velocity profile  48  is identified downstream from the perforated plate  26 . 
         [0064]    In at least one embodiment as depicted in  FIG. 7  the heat transfer system is substantially identical to the heat transfer system as depicted in  FIG. 6 , with the exception that turning vanes  50  are disposed proximate to the exhaust.  FIG. 7  does not depicted the velocity profile  48 . In  FIG. 7  the turning vanes  50  replace the perforated plate  26 . In addition, as may be seen in  FIG. 7 , in some embodiments a tube panel  10  will be disposed for fluid flow communication with the exhaust gas to establish a velocity profile in a location at or near the position as identified for the perforated plate  26 . 
         [0065]    In at least one embodiment as depicted in  FIG. 8  the dual function heat transfer surface/system is disclosed. The system of  FIG. 8  is substantially identical to the heat transfer system as depicted in  FIG. 6 , with the exception that a tube panel  10  is provided having the high pressure drop zone  18 , intermediate pressure drop zone  20 , and low pressure drop zone  22 , which are positioned at a location proximate to the exhaust of the super heater in substitution for the perforated plate  26 . 
         [0066]    In some embodiments, in addition to the high pressure drop zone  18 , intermediate pressure drop zone  20 , and low pressure drop zone  22 , as identified in  FIG. 8  and  FIG. 9 , additional pressure drop zones may be utilized vertically to supplement the pressure drop zones as identified. 
         [0067]    In some embodiments as shown in  FIG. 9  a tube panel  10  of the invention is shown. The tube panel  10  includes a panel upper header  1  at the top of the panel and a panel lower header  5  at the bottom of the panel. Each of the panel upper header  1  and panel lower header  5  include a header nozzle  2  permitting flow into and out of the tube panel  10 . The panel upper header  1  may also include inlet piping  12  and the panel lower header  5  may also include outlet piping  14 . It should be noted that the direction of flow within the tube panel  10  may be reversed. In some embodiments the tube panel  10  proximate to the top, may include heat transfer tubes  16  which are bare of fins  24  as depicted by reference numeral  6 . ( FIG. 18 ) Below the section of bare tubes  6  may be located a section of heat transfer tubes  16  having low pressure drop finning  7 . The low pressure drop finning  7  on the heat transfer tubes  16  in some embodiments may decrease the number of fins  24 , decrease the size of fins  24  and may also increase the separation dimension or distance between fins  24  which are proximate to each other in either the vertical or horizontal direction. 
         [0068]    In some embodiments as shown in  FIG. 9 , tube ties  4  will be located between the low pressure drop finning  7  and the intermediate pressure drop finning  8 . The tube ties  4  are used to establish sections of heat transfer tubes  16  having an identical fin configuration and spacing in order to establish a desired type of pressure drop zone. In addition as shown in  FIG. 9 , tube ties  4  may be located between the intermediate pressure drop finning  8  and the high pressure drop finning  9 . 
         [0069]    In at least one embodiment as shown in  FIG. 10 , within a low pressure drop zone  22  the heat transfer tubes  16  may have a uniform spacing between adjacent tubes within the same row. In addition, uniform spacing may be provided between adjacent rows of heat transfer tubes  16 . Further, adjacent rows of heat transfer tubes  16  may be slightly offset relative to each other so that an individual heat transfer tube  16  is generally disposed in the space between two heat transfer tubes  16  of an adjacent row. In addition to the three rows of heat transfer tubes  16  identified in  FIG. 10 , it should be noted that any number of rows of heat transfer tubes  16  may be utilized to establish a desired exhaust gas velocity profile. In some embodiments, heat transfer tubes  16  within a low pressure drop zone  22  may not include fins  24 . Alternatively, the heat transfer tubes  16  may include fins  24  which are disposed at a greater dimensional distance away from, or relative to each other, in order to establish a desired exhaust gas velocity profile. 
         [0070]    Alternatively, the heat transfer tubes  16  may include fins  24  having decreased surface area dimensions and/or thickness in order to establish a desired exhaust gas velocity profile in the low pressure drop zone  22 . 
         [0071]    In some embodiments, more or less than three rows of heat transfer tubes  16  may be used to form a low pressure drop zone  22 . In addition, the diameter dimension of the heat transfer tubes  16  may be decreased in order to establish a desired exhaust gas velocity profile. Further, in some embodiments is not required that each of the heat transfer tubes  16  forming a tube panel  10  within a low pressure drop zone  22  include identical features, which may include, but are not necessarily limited to tube diameter, fin  24  spacing, and/or fin  24  size or dimensions. In some embodiments, any combination of heat transfer tube  16  diameter size, fin  24  spacing and/or fin  24  size or dimension may be combined together to provide the desired exhaust gas velocity profile in the low pressure drop zone  22 . 
         [0072]    In some embodiments as shown in  FIG. 11 , the heat transfer tubes  16  within an intermediate pressure drop zone  20  are identified having regular spacing between adjacent heat transfer tubes  16  within an individual row. However, a second row  52  of heat transfer tubes  16  may be separated from the first row  54  of heat transfer tubes  16  by an increased dimension as compared to the separation distance between the second row  52  and the third row  56  of heat transfer tubes  16 , which are disposed in close proximity to each other. 
         [0073]    In some embodiments the heat transfer tubes  16  within an intermediate pressure drop zone  20  between adjacent rows are offset relative to each other to dispose a heat transfer tube  16  between two heat transfer tubes  16  in an adjacent row. In some embodiments within an intermediate pressure drop zone  20  the first row  54  and second row  52  of heat transfer tubes may be adjacent to each other and the third row  56  of heat transfer tubes may be separated from the second row  52  of heat transfer tubes by an increased spatial dimension. 
         [0074]    In addition to the three rows of heat transfer tubes  16  identified in  FIG. 11 , it should be noted that any number of rows of heat transfer tubes  16  may be utilized to establish a desired exhaust gas velocity profile within an intermediate pressure drop zone  20 . 
         [0075]    In some embodiments, heat transfer tubes  16  within an intermediate pressure drop zone  20  may include fins  24 . The fins  24  on the heat transfer tubes  16  within the intermediate pressure drop zone  20  may be disposed a smaller distance away from, or relative to each other, as compared to the low pressure drop zone  22 , in order to establish a desired exhaust gas velocity profile. Alternatively, the heat transfer tubes  16  may include fins  24  having an increased surface area dimensions and/or thickness as compared to the fins  24  on heat transfer tubes  16  within the low pressure drop zone  22 . 
         [0076]    In some embodiments, more or less than three rows of heat transfer tubes  16  may be used to form an intermediate pressure drop zone  20 . In addition, the diameter dimension of the heat transfer tubes  16  in the intermediate pressure drop zone  20  may be increased relative to the low pressure drop zone  22  in order to establish a desired exhaust gas velocity profile. Further, in some embodiments it is not required that each of the heat transfer tubes  16  forming a tube panel  10  within an intermediate pressure drop zone  20  include identical features, which may include, but are not necessarily limited to tube diameter, fin  24  spacing, and/or fin  24  size or dimensions. In some embodiments, any combination of heat transfer tube  16  diameter size, fin  24  spacing and/or fin  24  size or dimension may be combined together to provide the desired exhaust gas velocity profile in the intermediate pressure drop zone  20 . 
         [0077]    In some embodiments as depicted in  FIG. 12  for a high pressure drop zone  18 , the second row  52  and third row  56  of heat transfer tubes  16  may be in close proximity to each other, and in an alternative embodiment the fins  24  of the second row  52  and the third row  56  of heat transfer tubes  16  may contact each other. In some embodiments as shown in  FIG. 12 , the heat transfer tubes  16  within a high pressure drop zone  18  are identified having regular spacing between adjacent heat transfer tubes  16  within an individual row. However, a second row  52  of heat transfer tubes  16  may be separated from the first row  54  of heat transfer tubes  16  by an increased dimension as compared to the separation distance between the second row  52  and the third row  56  of heat transfer tubes  16 , which may disposed in contact with each other. 
         [0078]    In some embodiments the heat transfer tubes  16  within a high pressure drop zone  18  between adjacent rows are offset relative to each other to dispose a heat transfer tube  16  between two heat transfer tubes  16  in an adjacent row. In some embodiments within a high pressure drop zone  18  the first row  54  and second row  52  of heat transfer tubes may be adjacent to each other and the third row  56  of heat transfer tubes may be separated from the second row  52  of heat transfer tubes by an increased spatial dimension. 
         [0079]    In addition to the three rows of heat transfer tubes  16  identified in  FIG. 12 , it should be noted that any number of rows of heat transfer tubes  16  may be utilized to establish a desired exhaust gas velocity profile within a high pressure drop zone  18 . In some embodiments, heat transfer tubes  16  within a high pressure drop zone  18  may include fins  24 . The fins  24  on the heat transfer tubes  16  within the high pressure drop zone  18  may be disposed a smaller distance away from, or relative to each other, as compared to the intermediate pressure drop zone  20 , in order to establish a desired exhaust gas velocity profile. Alternatively, the heat transfer tubes  16  may include fins  24  having an increased surface area dimensions and/or thickness as compared to the fins  24  on heat transfer tubes  16  within the intermediate pressure drop zone  20 , in order to establish a desired exhaust gas velocity profile. 
         [0080]    In some embodiments, more or less than three rows of heat transfer tubes  16  may be used to form a high pressure drop zone  18 . In addition, the diameter dimension of the heat transfer tubes  16  in the high pressure drop zone  18  may be increased relative to the intermediate pressure drop zone  20  in order to establish a desired exhaust gas velocity profile. Further, in some embodiments it is not required that each of the heat transfer tubes  16  forming a tube panel  10  within a high pressure drop zone  18  include identical features, which may include, but are not necessarily limited to tube diameter, fin  24  spacing, and/or fin  24  size or dimensions. In some embodiments, any combination of heat transfer tube  16  diameter size, fin  24  spacing and/or fin  24  size or dimension may be combined together to provide the desired exhaust gas velocity profile in the high pressure drop zone  18 . 
         [0081]    In some embodiments, as depicted in  FIG. 13 , any desired portion of a tube panel  10  may include any desired configuration of heat transfer tube spacing between adjacent heat transfer tubes  16  and adjacent rows of heat transfer tubes  16 . For example, in the left section or portion of the tube panel  10  disclosed in  FIG. 13 , the second row  52  and the third row  56  of heat transfer tubes  16  are spatially separated from the first row  54  of heat transfer tubes  16 . In addition, in the left section or portion of the tube panel  10  disclosed in  FIG. 13 , the heat transfer tubes  16  in each of the second row  52  and the third row  56  are closely longitudinally spaced, or are in contact with each other. In addition, in the left section of the tube panel  10  as disclosed in  FIG. 13 , the second row  52  of heat transfer tubes  16  is in close proximity to the third row  56  of heat transfer tubes  16  and in some embodiments may be in contact with each other. 
         [0082]    As shown in  FIG. 13 , in some embodiments in the middle portion or section, and right portion or section, of the tube panel  10 , the first row  54 , second row  52 , and third row  56  of heat transfer tubes  16  are regularly and uniformly spaced relative to each other. In some embodiments, any spacing between heat transfer tubes  16  within an individual row or between rows of adjacent heat transfer tubes  16  may be utilized within sections or portions of a tube panel  10  in any combination, to provide a desired velocity profile. In addition, in some embodiments, the spacing between adjacent heat transfer tubes  16  within an individual row may be adjusted, where certain heat transfer tubes  16  are compacted relative to each other, and where other heat transfer tubes  16  are separated or regularly spaced relative to each other longitudinally along the length of the row within the tube panel  10 . 
         [0083]    Further, in some embodiments, the size of the diameter of the heat transfer tubes  16  within an individual row may vary, where certain heat transfer tubes  16  have a larger or smaller diameter dimension relative to another of the heat transfer tubes  16  along the length of the row within the tube panel  10 . In addition, heat transfer tubes  16  may have a larger or smaller diameter dimension between rows of heat transfer tubes  16  in any combination, within the tube panel  10 . 
         [0084]    In some embodiments the heat transfer tubes  16  within a pressure drop zone between adjacent rows may be aligned or offset relative to each other. In addition to the three rows of heat transfer tubes  16  identified in  FIG. 13 , it should be noted that any number of rows of heat transfer tubes  16  may be utilized to establish a desired exhaust gas velocity profile within a pressure drop zone. 
         [0085]    In some embodiments, heat transfer tubes  16  within a pressure drop zone may include fins  24 . The fins  24  on the heat transfer tubes  16  within a pressure drop zone may be disposed either a larger or a smaller distance away from, or relative to each other, as compared to another row or section of a tube panel  10 , in order to establish a desired exhaust gas velocity profile. Alternatively, the heat transfer tubes  16  may include fins  24  having either an increased or decreased surface area dimensions and/or thickness as compared to the fins  24  on adjacent heat transfer tubes  16  or within adjacent rows of heat transfer tubes  16  within a pressure drop zone in order to establish a desired exhaust gas velocity profile. 
         [0086]    In  FIGS. 10 through 13  the flow of heated air through tube panel  10  which is used to create a desired pressure drop zone is depicted by arrow  58 . It should be noted that the velocity profiles established by the pressure drop zones depicted in  FIGS. 10-13  may be vertically arranged in any combination. In alternative embodiments, a velocity profile established by a pressure drop zone may use only one or more of the pressure drop zones depicted in  FIGS. 10-13  in any combination. 
         [0087]    In some embodiments as depicted in  FIGS. 14, 15, and 16  the longitudinal spacing between heat transfer tubes  16 , the separation distance and/or spacing of heat transfer tubes  16  into bundles within a particular row, the spacing between the rows of heat transfer tubes  16  in a tube panel  10 , and the alignment of the heat transfer tubes  16  between adjacent rows of heat transfer tubes  16  within a tube panel  10 , may vary in order to provide or to modify the gas flow characteristics through the tube panel  10 . 
         [0088]    In at least one embodiment as depicted in  FIG. 14  a low pressure drop configuration or zone  22  may have a longitudinal tube to tube spacing dimension (depicted by SL (reference numeral  60 )) of 3.5 to 5.0 inches, a transverse tube to tube spacing dimension (depicted by ST (reference numeral  62 )) of 3.5 to 4.625 inches, and aligned tube spacing dimension  64  of 0.5 to 0.75 inches. In other embodiments, the low pressure drop zone  22  longitudinal tube to tube spacing dimension SL  60  may be greater than 3.5 to 5.0 inches, and the transverse tube to tube spacing dimension ST  62  may be greater than 3.5 to 4.625 inches, and the aligned tube spacing dimension  64  may be greater than 0.5 to 0.75 inches. In other embodiments, the low pressure drop zone  22  longitudinal tube to tube spacing dimension SL  60  may be less than 3.5 to 5.0 inches, and the transverse tube to tube spacing dimension ST  62  may be less than 3.5 to 4.625 inches, and the aligned tube spacing dimension  64  may be less than 0.5 to 0.75 inches. It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . In  FIG. 14 , the fin tip to fin tip separation dimension between adjacent heat transfer tubes  16  within a particular row is depicted by reference numeral  66 . 
         [0089]    In at least one embodiment as depicted in  FIG. 15 , an intermediate pressure drop configuration or zone  20  may have a longitudinal tube to tube spacing dimension SL  60  of 3.0 to 4.5 inches, a transverse tube to tube spacing dimension ST  62  of 3.5 to 4.625 inches, and an aligned tube spacing dimension  64  of 0.125 to 0.75 inches. In other embodiments, the intermediate pressure drop zone  20  longitudinal tube to tube spacing dimension SL  60  may be greater than 3.0 to 4.5 inches, and the transverse tube to tube spacing dimension ST  62  may be greater than 3.5 to 4.625 inches, and the aligned tube spacing dimension  64  may be greater than 0.125 to 0.75 inches. In other embodiments, the intermediate pressure drop zone  20  longitudinal tube to tube spacing dimension SL  60  may be less than 3.0 to 4.5 inches, and the transverse tube to tube spacing dimension ST  62  may be less than 3.5 to 4.625 inches, and the aligned tube spacing dimension  64  may be less than 0.125 to 0.75 inches. It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . 
         [0090]    In at least one embodiment as depicted in  FIG. 16 , a high pressure drop configuration or zone  18  may have a longitudinal tube to tube spacing dimension SL  60  of 2.75 to 4.0 inches, a transverse tube to tube spacing dimension ST  62  of 3.5 to 4.625 inches, and aligned tube spacing dimension  64  of 0 (fin tips touching) to 0.250 inches. In other embodiments, the high pressure drop zone  18  longitudinal tube to tube spacing dimension SL  60  may be greater than 2.75 to 4.0 inches, and the transverse tube to tube spacing dimension ST  62  may be greater than 3.5 to 4.625 inches, and the aligned tube spacing dimension  64  may be greater than 0 (fin tips touching) to 0.250 inches. In other embodiments, the high pressure drop zone  18  longitudinal tube to tube spacing dimension SL  60  may be less than 2.75 to 4.0 inches, and the transverse tube to tube spacing dimension ST  62  may be less than 3.5 to 4.625 inches, and the aligned tube spacing dimension  64  may be less than 0.250 inches. It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . 
         [0091]    In at least one embodiment as depicted in  FIGS. 17 a  and 17 b   , the tube fin  24  geometry dimensions may vary between one or more of the possible pressure drop configurations or zones. In some embodiments, the fin  24  thickness dimension FT  68  will be between 0.039 to 0.059 inches, and the finning segment width Y dimension  70  will be between 0.15 to 0.2 inches for all pressure drop configurations or zones. In other embodiments the fin  24  thickness dimension FT  68  will be greater than between 0.039 to 0.059 inches, and the finning segment width Y dimension  70  will be greater than between 0.15 to 0.2 inches for the low pressure drop zone  22 . In other embodiments the fin  24  thickness dimension FT  68  will be less than between 0.039 to 0.059 inches, and the finning segment width Y dimension  70  will be less than between 0.15 to 0.2 inches for high pressure drop zone  18 . It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . 
         [0092]    In some embodiments the fin  24  height dimension FH  72  may be varied to modify the gas flow characteristics through the tube panel  10 . In a high pressure drop zone  18  the fin  24  height dimension FH  72  may range from approximately 0.625 to 0.75 inches. In other embodiments, in a high pressure drop zone  18 , the fin  24  height dimension FH  72  may be greater than approximately 0.625 to 0.75 inches and in other embodiments the fin  24  height dimension FH  72  in a high pressure drop zone  18  may be less than approximately 0.625 to 0.75 inches. It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . 
         [0093]    In some embodiments the fin  24  height dimension FH  72  in an intermediate pressure drop zone  20  may range from approximately 0.375 to 0.75 inches. In other embodiments, the fin  24  height dimension FH  72  in an intermediate pressure drop zone  20  may be greater than approximately 0.375 to 0.75 inches, and in other embodiments the fin  24  height dimension FH  72  in an intermediate pressure drop zone  20 , may be less than approximately 0.375 to 0.75 inches. It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . 
         [0094]    In some embodiments the fin  24  height dimension FH  72  in a low pressure drop zone  22  may range from approximately 0.2 to 0.5 inches. In other embodiments, the fin  24  height dimension FH  72  in a low pressure drop zone  22  may be greater than approximately 0.2 to 0.5 0.75 inches and in other embodiments the fin  24  height dimension FH  72  in a low pressure drop zone  22 , may be less than approximately 0.2 to 0.5 inches. It should be noted that the dimensions identified herein have been provided for illustrative purposes, and may be increased, decreased, or varied dependent upon the requirements of a particular tube panel  10 . 
         [0095]    In alternative embodiments, the fins  24  may be directly engaged to the exterior surface of a heat transfer tube  16 . In at least one embodiment, the extended surface or fins  24  are preferably formed of metal material. Generally, the heat transfer tubes  16  as identified herein are disposed vertically relative to each other in order to define a vertical axis. In an alternative embodiment, the heat transfer tubes  16  may be disposed horizontally relative to each other. In some embodiments, the fins  24  extend outwardly from the heat transfer tubes  16  in a direction which is perpendicular to the vertical axis. In some embodiments, the fins  24  may be aligned horizontally and/or aligned vertically, where adjacent fins  24  are parallel to each other and fins  24  on adjacent drop zone levels are vertically aligned relative to each other. 
         [0096]    In some alternative embodiments, the fins  24  may be aligned vertically or offset vertically in a desired pattern or configuration, one example of which may be to form a spiral. In an alternative embodiment, the fins  24  may extend outwardly from the heat transfer tube  16  and may be disposed at an angle relative to the vertical axis. In this embodiment, adjacent fins  24  are angularly offset relative to a vertical axis and may be parallel to each other. In some alternative embodiments, the angled fins  24  may be aligned vertically or offset vertically in a desired pattern or configuration, one example of which may be to form a spiral. 
         [0097]    In some embodiments, the fins  24  may have uniform size dimensions and/or shapes creating a unitary structure without spaces between adjacent fins  24 . In alternative embodiments the fins  24  may be formed in a segmented configuration with a space between adjacent fins  24 . The space between adjacent fins  24  may be increased or decreased in dimension, uniform, and/or non-uniform, dependent on a desired high pressure drop zone  18 , intermediate pressure drop zone  20 , or low-pressure drop zone  22  in order to provide a desired gas velocity profile. 
         [0098]    In some embodiments, any fin  24  configuration or fin  24  spacing as disclosed herein may be utilized in any combination with one or more of any other fin  24  configuration or spacing as alternatively described. In addition any number of sections or sectors of fins  24  may be utilized to provide a desired exhaust gas flow velocity profile. 
         [0099]    In some embodiments as shown in  FIG. 18 , in a high pressure drop zone  18  the fins  24  as disposed on the tube panel  10  are tightly spaced vertically relative to each other. In the high pressure drop zone  18  the number of fins  24  is maximized vertically along a desired portion of the tube panel  10 . In the intermediate pressure drop zone  20 , the number of fins  24  disposed in the tube panel  10  is reduced, and the spacing between adjacent fins  24  is increased relative to the high pressure drop zone  18 . In the low-pressure drop zone  22 , the number of fins  24  disposed on the tube panel  10  is further reduced relative to the spacing in the intermediate pressure drop zone  20 . In addition in the low pressure drop zone  22  the spacing between adjacent fins  24  on the tube panel  10  is increased in either of the vertical or horizontal directions. In addition, the spacing between heat transfer tubes  16  in the low pressure drop zone  22  is increased relative to the intermediate pressure drop zone  20 . 
         [0100]    In some embodiments spacing between adjacent heat transfer tubes  16  within a row of tubes in a tube panel  10  is obtained through the use of tube ties, restraints, fasteners, or tube frames  4  having a desired spacing configuration. In addition, in some embodiments, the spacing between adjacent rows of heat transfer tubes  16  within a tube panel  10  is obtained through the use of tube ties, restraints, fasteners, or tube frames having a desired spacing and/or positioning configuration. 
         [0101]    In at least one embodiment as depicted in  FIG. 19 , the tube panel  10  or multiple tube panels  10  may positioned adjacent to each other, where each tube panel  10  may be comprised of areas of low, intermediate, and/or high gas pressure drop zones  22 ,  20  and  18  respectively, with the highest gas pressure drop being typically located at the bottom of a tube panel  10 . A “bundle” of heat transfer tubes  16  is a term used to describe multiple conjoined tube panels  10 . 
         [0102]    In a first alternative embodiment, a heat transfer device is disclosed comprising: a plurality of tubes, the plurality of tubes being disposed in rows of tubes, the rows of tubes forming a tube panel wherein the plurality of rows of tubes are vertically organized into a least a first pressure drop zone and a second pressure drop zone. 
         [0103]    In a second alternative embodiment according to the first alternative embodiment, the plurality of tubes within at least one of the rows of the plurality of tubes are uniformly spaced relative to another of the plurality of tubes within the at least one of the rows of tubes. 
         [0104]    In a third alternative embodiment according to the first alternative embodiment, the plurality of tubes within at least one of the rows of the plurality of tubes are irregularly spaced relative to another of the plurality of tubes within the at least one of the rows of tubes. 
         [0105]    In a fourth alternative embodiment according to the first alternative embodiment, the plurality of tubes within the first pressure drop zone are separated from each other a first distance, and the plurality of tubes within the second pressure drop zone are separated from each other a second distance, the first distance having a different dimension as compared to the second distance. 
         [0106]    In a fifth alternative embodiment according to the first alternative embodiment, a plurality of fins may be engaged to at least one of the plurality of tubes where a first number of fins may be engaged to each of the plurality of tubes in the first pressure drop zone and a second number of fins may be engaged to each of the plurality of tubes in the second pressure drop zone, the first number of fins being different from the second number of fins. 
         [0107]    In a sixth alternative embodiment according to the second alternative embodiment, the spacing between adjacent rows of tubes defines a transverse tube spacing having a dimension, the dimension being constructed and arranged to be variable and to modify a gas flow characteristic of the heat transfer device to achieve a desired flow distribution. 
         [0108]    In a seventh alternative embodiment according to the first alternative embodiment, the tube panel is constructed and arranged to act as a heat transfer surface and is constructed and arranged to distribute turbulent combustion turbine exhaust flow. 
         [0109]    In an eighth alternative embodiment according to the fifth alternative embodiment, the first number of fins and the second number of fins are constructed and arranged to establish a desired exhaust gas flow distribution downstream from the tube panel. 
         [0110]    In a ninth alternative embodiment according to the first alternative embodiment, the tube panel comprises a panel upper header and a panel lower header, each of the panel upper header and the panel lower header having a header nozzle. 
         [0111]    In a tenth alternative embodiment according to the first alternative embodiment, the heat transfer device further comprises tube ties, wherein the tube ties secure the plurality of tubes into the first pressure drop zone and the second pressure drop zone. 
         [0112]    In an eleventh alternative embodiment according to the first or fifth alternative embodiments, at least one of the plurality of rows of tubes are vertically organized into an intermediate pressure drop zone. 
         [0113]    In a twelfth alternative embodiment according to the eleventh alternative embodiment, the plurality of tubes within the intermediate pressure drop zone are separated from each other a third distance, the third distance being smaller than the second distance and the third distance being larger than the first distance. 
         [0114]    In a thirteenth alternative embodiment according to the twelfth alternative embodiment, a third number of fins is engaged to at least one of the plurality of tubes in the intermediate pressure drop zone, the third number of fins being larger than the second number of fins, and the third number of fins being smaller than the first number of fins. 
         [0115]    In a fourteenth alternative embodiment according to the thirteenth alternative embodiment, the first number of fins, the third number of fins, and the second number of fins are constructed and arranged to establish a desired exhaust gas flow distribution downstream from the tube panel. 
         [0116]    In another alternative embodiment, a tube panel, or multiple panels will act as both a heat transfer surface utilized in a waste heat boiler as part of the Rankin cycle, as well as a device to distribute turbulent combustion turbine exhaust flow for downstream components which require uniform gas flow. 
         [0117]    In another alternative embodiment, a tube panel, or multiple panels have extended surfaces, where the extended surfaces along the length of the tubes is varied in order to achieve a desired exhaust gas flow distribution. 
         [0118]    In another alternative embodiment, a tube panel, or multiple panels include a longitudinal tube spacing between the tubes which is varied to modify the gas flow characteristics to achieve desired flow distribution. 
         [0119]    This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto. 
         [0120]    The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. The various elements shown in the individual figures and described above may be combined or modified for combination as desired. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”.