The present invention relates, in general, to the field of heat exchangers and, more particularly, to a heat exchanger having an integral support structure and a structural framework for the support thereof.
The present invention employs the teachings of U.S. Pat. No. 6,336,429 to Wiener et al., the text of which is hereby incorporated by reference as though fully set forth herein.
To the extent that explanations of certain terminology or principles of the heat exchanger, boiler and/or steam generator arts may be necessary to understand the present invention, the reader is referred to Steam/its generation and use, 40th Edition, Stultz and Kitto, Eds., Copyright ©1992, The Babcock & Wilcox Company, and to Steam/its generation and use, 41st Edition, Kitto and Stultz, Eds., Copyright ©2005, The Babcock & Wilcox Company, the texts of which are hereby incorporated by reference as though fully set forth herein.
One aspect of the present invention is drawn to a heat exchanger for transferring heat energy into a working fluid, such as water. The heat exchanger is used to transform at least a portion of the water from the liquid phase into saturated or superheated steam.
Vertical steam/water separating devices, disclosed in the aforementioned U.S. Pat. No. 6,336,429 to Wiener et al., are used to separate the steam from the steam-water mixture. A pair of such vertical steam/water separators, structurally interconnected and arranged as described herein, provides an integral support structure for the heat exchanger.
The heat exchanger of the present invention is advantageously comprised of an arrangement of heat transfer surfaces and fluid conveying conduits arranged in a particular fashion to transfer a desired amount of heat energy into the water. The heat transfer surfaces are advantageously made of tubes arranged into panels, and are provided with inlet and outlet headers as required. As is known to those skilled in the art, heat transfer surfaces which convey steam-water mixtures are commonly referred to as evaporative or boiler surfaces; heat transfer surfaces which convey steam therethrough are commonly referred to as superheating (or reheating, depending upon the associated steam turbine configuration) surfaces. Regardless of the type of heating surface, the sizes of tubes, their material, diameter, wall thickness, number and arrangement are based upon temperature and pressure for service, according to applicable boiler design codes, such as the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section I, or equivalent other codes as required by law. Required heat transfer characteristics, pressure drop, circulation ratios, spot absorption rates, mass flow rates of the working fluid within the tubes, etc. are also important parameters which must be considered. Depending upon the geographic location where the heat exchanger is to be installed, applicable seismic loads and design codes are also considered.
The heat exchanger is bottom supported from a base which is part of an arrangement of interconnected rigid members that surrounds the heat exchanger and forms a structural support framework which, together with the aforementioned integral support structure not only provides structural support and rigidity for the heat exchanger, but also a means by which the heat exchanger can be picked up and lifted for placement at a desired location. In the case of an application of the heat exchanger as a solar heat energy receiver, the structural support framework permits the entire assembly of the heat exchanger and the framework to be assembled on the ground and then lifted and set upon a tower during installation. The structural support framework remains with the heat exchanger, thereby facilitating (if necessary) the removal of the heat exchanger from the tower should it become desirable to do so.
In accordance with the present invention, there is provided a heat exchanger comprising an arrangement of heat transfer surfaces and a pair of vertical steam/water separators structurally interconnected to one another and providing an integral support structure for at least a portion of the heat transfer surfaces of the heat exchanger. The structural interconnection includes upper and lower structural members formed of heavy wall pipe and extending between the vertical steam/water separators. Each of the heavy wall pipes includes a pair of spaced inner partition walls disposed in crosswise fashion to form a central portion therein defining a header. The integrally supported portion of the heat transfer surfaces extends between and is fluidically connected to the headers of the upper and lower structural members.
Each of the vertical steam/water separators includes four coplanar pedestal feet positioned at the lower end of the steam/water separator, and arranged at equally spaced intervals about the outer periphery of the steam/water separator.
The heat exchanger includes a structural support framework in the shape of a rectangular parallelepiped having a top, a bottom and opposing lengthwise sides surrounding the heat exchanger for bottom support thereof.
The bottom of the structural support framework is comprised of four horizontally extending parallel spaced lateral and longitudinal beams intersecting one another to form a grid-like structure which includes a lattice of obliquely-disposed web members positioned between intersecting longitudinal and lateral beams.
Two pairs of lateral braces intersect the inner two of the four longitudinal beams of the bottom of the structural support framework to form support bases for the vertical steam/water separators. The pedestal feet of the steam/water separator are fixedly secured to the respective support base.
Each of the opposing lengthwise sides of the structural support framework has two pairs of parallel spaced vertical beams located at opposite ends of the structural framework and one pair of parallel spaced longitudinal beams intersecting the vertical beams and located at the upper end of each of the opposing sides. A lattice of obliquely-disposed web members is positioned between each pair of vertical beams and the pair of longitudinal beams.
The top of the structural support framework is comprised of two lateral beams intersecting the upper one of the pair of parallel spaced beams extending along each lengthwise side. The two lateral beams are located above the heat exchanger and provide a means by which the heat exchanger and the structural support framework can be lifted for placement at a desired location.
Another aspect of the present invention is drawn to the combination of a heat exchanger and the structural framework used for the support thereof. The combination comprises an arrangement of heat transfer surfaces and a pair of vertical steam/water separators structurally interconnected to one another and providing an integral support structure for at least a portion of the heat transfer surfaces. The structural interconnection between the heat exchanger surfaces and the pair of vertical steam/water separators is comprised of upper and lower heavy wall pipes, each pipe having partitions therein defining a central header. The integrally supported portion of the heat transfer surfaces extends between and is fluidically connected to the headers of the upper and lower heavy wall pipes. Each of the steam/water separators includes a plurality of pedestal feet positioned at the lower end of the steam/water separator.
The structural framework part of the combination has a top, a bottom, and opposing lengthwise sides surrounding the heat exchanger for bottom support thereof. The bottom of the structural framework is comprised of four horizontally extending parallel spaced lateral and longitudinal beams intersecting one another to form a grid-like structure and includes a lattice of obliquely-disposed web members positioned between intersecting longitudinal and lateral beams. Two pairs of parallel spaced lateral braces intersect the inner two of the four longitudinal beams at the bottom of the structural framework to form support bases for the vertical steam/water separators whose pedestal feet are fixedly secured to their respective support bases. Each of the opposing lengthwise sides of the structural framework has two pairs of parallel spaced vertical beams located at opposite ends of the structural framework and one pair of parallel spaced longitudinal beams intersecting the vertical beams and located at the upper end of each of the opposing sides. A lattice of obliquely-disposed web members positioned between each pair of vertical beams and the pair of longitudinal beams. The top of the structural framework is comprised of two lateral beams intersecting the upper one of said pair of parallel beams. The two lateral beams are located above the heat exchanger and provide a means by which the heat exchanger and the structural framework can be lifted for placement at a desired location.
These and other features of the present invention will be better understood and its advantages will be more readily appreciated from the following description, especially when read with reference to the accompanying drawings.
Reference will hereinafter be made to the accompanying drawings wherein like numerals designate the same or functionally similar elements throughout the various drawings.
Referring to
If the heat exchanger 10 is used to provide merely saturated steam, the side walls 12 and roof portion 14 comprise evaporative or boiler heating surface. If the heat exchanger 10 is used to provide superheated steam, and as will be appreciated by those skilled in the art, some of the heating surface will have to be evaporative surface and other portions will have to be superheater surface. In the embodiment shown in
Referring to
Referring to
It will be noted that the heating surface 38 extends in between the headers 36 of the upper and lower structural members 32 while providing a gap or space 42 between distal edges of the heating surface 38 and the outer wall of the steam/water separators 16. The side walls 12 extend into this space 42, with the distal edges of the heating surface 38 extending adjacent to and in close proximity with the inside portions of the side walls 12. However, in order to accommodate differential thermal expansion the heating surface 38 is not connected to the side walls 12 in any rigid fashion. The side walls 12 would be bottom supported from a base, in a fashion similar to that described below with respect to the integral support structure 30. The sidewalls 12 may also be provided with buckstays, not shown, which are well known to those skilled in the art as providing rigidity and support for membrane tube wall construction.
Referring to
The three dimensional structural framework 50 is generally in a shape of a rectangular parallelepiped and is defined by the top 51, the bottom 52, and the lengthwise sides 55, and includes three sets of flanged beams extending in the three mutually orthogonal directions, eight longitudinal beams 58, six lateral beams 56, and eight vertical beams 54.
The bottom 52 of the structural framework 50 is comprised of four parallel spaced longitudinal beams 58 and four parallel spaced lateral beams 56 which connectedly intersect one another to form a grid-like structure. A lattice of obliquely-disposed web members 60 is positioned between the intersecting longitudinal and lateral beams 58 and 56 to structurally reinforce the grid-like structure forming the bottom 52 and to stiffen or add rigidity to the structural framework 50.
The bottom 52 of the structural framework 50 includes a pair of support bases 53, each being formed by respective pairs of parallel spaced lateral braces 57 connectedly intersecting the inner pair of longitudinal beams 58. Each of the steam/water separators 16 includes four pedestal feet 59 located at or near the bottom of the steam/water separator. The pedestal feet 59 extend outwardly from the steam/water separator wall at a substantially right angle, and are coplanar and arranged at equally spaced intervals about the outer periphery of the steam/water separator 16. The pedestal feet 59 are each provided with a reinforcing gusset 61 and are fixedly secured to the support base 53.
Each of the lengthwise sides 55 of the structural framework 50 is comprised of two pairs of parallel spaced vertical beams 54 located at opposite ends of the structural framework 50, and one pair of parallel spaced longitudinal beams 58 located at the upper end of the sides 55 and connectedly intersecting the vertical beams 54. A lattice of obliquely-disposed web members 60 is positioned between each pair of vertical beams 54 and the longitudinal beams 58 to structurally reinforce the sides 55 and to stiffen the structural framework 50.
The top 51 of the structural framework 50 is comprised of two lateral beams 56 which intersect and are connected to the upper one of each of the pairs of longitudinal beams 58 located at the upper end of the lengthwise sides 55. In addition to reinforcing the top 51 and stiffening the structural framework 50, the top lateral beams 56 are generally located over the heat exchanger 10 and provide a means by which the heat exchanger 10 and the supporting structural framework 50 can be picked up and lifted for placement at a desired location.
Although the present invention has been described above with reference to particular means, materials, and embodiments, it is to be understood that this invention may be varied in many ways without departing from the spirit and scope thereof, and therefore is not limited to these disclosed particulars but extends instead to all equivalents within the scope of the following claims.
Number | Date | Country | |
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61020882 | Jan 2008 | US |