BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to large scale field erected air cooled industrial steam condensers.

Description of the Background

The typical large scale field erected air cooled industrial steam condenser is constructed of heat exchange bundles arranged in an A-frame arrangement above a large fan, with one A-frame per fan. Each tube bundle typically contains 35-45 vertically oriented flattened finned tubes, each tube approximately 11 meters in length by 200 mm in height, with semi-circular leading and trailing edges, and 18-22 mm external width. Each A-frame typically contains five to seven tube bundles per side.

The typical A-Frame ACC described above also includes both 1ststage or “primary” condenser bundles (sometimes referred to as K-bundles for Kondensor) and 2ndstage or “secondary” condenser bundles (sometimes referred to as D-bundles for Dephlegmator). About 80% to 90% of the heat exchanger bundles are 1ststage or primary condenser. The steam enters the top of the primary condenser bundles and the condensate and some steam leave the bottom. In the 1ststage the steam and condensate travel down the heat exchanger bundles and this process is commonly referred to as the co-current condensing stage. The first stage configuration is thermally efficient; however, it does not provide a means for removing non-condensable gases. To sweep the non-condensable gases through the 1ststage bundles, 10% to 20% of the heat exchanger bundles are configured as 2ndstage or secondary condensers, typically interspersed among the primary condensers, which draw vapor from the lower condensate manifold. In this arrangement, steam and non-condensable gases travel through the 1ststage condensers as they are drawn into the bottom of the secondary condenser. As the mixture of gases travels up through the secondary condenser, the remainder of the steam condenses, concentrating the non-condensable gases at the top while the condensate drains to the bottom. This process is commonly referred to as the counter-current condensing stage. The tops of the secondary condensers are attached to a vacuum manifold which removes the non-condensable gases from the system.

Variations to the standard prior art ACC arrangement have been disclosed, for example in US 2015/0204611 and US 2015/0330709. These applications show the same finned tubes, but drastically shortened and then arranged in a series of small A-frames, typically five to six A-frames per fan. Part of the logic is to reduce the steam-side pressure drop, which has a small effect on overall capacity at summer condition, but greater effect at a winter condition. Another part of the logic is to weld the top steam manifold duct to each of the bundles at the factory and ship them together, thus saving expensive field welding labor. The net effect of this arrangement, with the steam manifold attached at the factory and shipped with the tube bundles, is a reduction of the tube length to accommodate the manifold in a shipping container.

Additional variations to the prior art ACC arrangements are disclosed, for example in US 2017/0363357 and US 2017/0363358. These applications disclose a new tube construction for use in ACCs having a cross-sectional height of 10 mm or less. US 2017/0363357 also discloses a new ACC arrangement having heat exchanger bundles in which the primary condenser bundles are arranged horizontally along the longitudinal axis of the bundles and the secondary bundles are arranged parallel to the transverse axis. US 2017/0363358 discloses an ACC arrangement in which all of the tube bundles are secondary bundles.

SUMMARY OF THE INVENTION

The invention presented herein is a new and improved design for large scale field-erected air cooled industrial steam condensers for power plants and the like which provides significant improvements and advantages over the ACCs of the prior art.

According to one embodiment of the present invention, heat exchanger panels are constructed with an integral secondary condenser section positioned in the center of the heat exchanger panel, flanked by primary condenser sections which may or may not be identical to one-another. A bottom bonnet runs along the bottom length of the heat exchanger panel, connected to the bottom side of the bottom tube sheet, for delivering steam to the bottom end of the primary condenser tubes. In this arrangement, the 1ststage of condensing occurs in counter-current operation. The tops of the tubes are connected to a top tube sheet, which in turn is connected on its top side to a top bonnet. Uncondensed steam and non-condensables flow into the top bonnet from the primary condenser tubes and flow toward the center of the heat exchanger panel where they enter the top of the secondary condenser section tubes. In this arrangement the 2ndstage of condensing occurs in co-current operation. Non-condensables and condensate flow out the bottom of the secondary tubes into an internal secondary chamber located inside the bottom bonnet. Non-condensables and condensate are drawn from the bottom bonnet secondary chamber via outlet nozzle, and condensate is drawn off and sent to join the water collected from the primary condenser sections.

According to an alternate embodiment, the heat exchanger panels may be constructed as single stage condenser heat exchange panels, in which all the tubes of the heat exchanger panels receive steam from and deliver condensate to the bottom bonnet, and non-condensables are drawn off via the top bonnet. More specifically, a bottom bonnet runs along the bottom length of the heat exchanger panel as with the multiple stage embodiment, connected to the bottom side of the bottom tube sheet, but in the single stage embodiment, the bottom bonnet delivers steam to the bottom end of all the tubes in the heat exchanger panel. As with the multiple stage embodiment, the tops of all of the tubes are connected to a top tube sheet, which in turn is connected on its top side to a top bonnet. Uncondensed steam and non-condensables flow into the top bonnet from all of the tubes in the heat exchanger panel and are drawn away from the top bonnet for further processing. Condensate flows out the bottom of all of the tubes into the bottom bonnet, and into the steam distribution manifold.

According to various embodiments of the invention, each heat exchanger panel may be independently loaded into and supported in the heat exchange section framework. According to one embodiment, adjacent panels may be inclined relative to vertical in opposite directions in an arrangement resembling an A-frame or V-frame type of arrangement, although there is preferably no relation or interaction between adjacent panels. According to another embodiment, each heat exchange panel may be oriented vertically, with an optional air deflection or seal positioned at an angle between each adjacent panel. According to a further embodiment, all of the heat exchange panels may be inclined at an angle relative to vertical, all in the same direction. According to yet another embodiment, all of the heat exchange panels on one side of a heat exchange section may be inclined relative to vertical in one direction, and all of the heat exchange panels on the other side of the heat exchange section may be inclined relative to vertical in an opposite direction.

According to some embodiments of the invention, each cell or module of the ACC has a plenum section module with a single fan large fan creating an air flow over all of the heat exchange panels in the same module.

According to other embodiments of the invention, the plenum section module may include a plurality of longitudinal fan deck plates arranged over the fan deck framework, each fan deck plate having a plurality of fans. According to various aspects of this embodiment, the fan deck plates may be aligned so that their longitudinal axis is parallel to or perpendicular to the longitudinal axes of the heat exchange panels in the same ACC module.

According to a further embodiment of the invention, a lower steam distribution manifold runs under a plurality of ACC cells/modules in a row, and the heat exchange panels of each cell or module of the ACC is fed by a single riser which delivers its steam to a dedicated upper steam distribution manifold, preferably comprising a large horizontal cylinder closed at both ends, suspended from below the heat exchange section support framework, perpendicular to the longitudinal axis of the heat exchanger panels, and beneath the center point of each heat exchanger panel. The upper steam distribution manifold feeds steam to the bottom bonnet of each heat exchanger panel at a single location at the center point of the each panel.

According to a further embodiment of the invention, the heat exchange module frame and the heat exchanger panels for each cell are pre-assembled at ground level. The heat exchange module frame is then supported on an assembly fixture just high enough to suspend the upper steam distribution manifold from the underside of the heat exchange module frame. Separately, the plenum section, which includes the fan deck and fan set for a corresponding heat exchange module, is likewise assembled at ground level. Sequentially or simultaneously, the understructure for the corresponding heat exchange module may be assembled in its final location. The heat exchange module, with the upper steam distribution manifold suspended therefrom, may then be lifted in its entirety and placed on top of the understructure, followed by similar lifting and placement of the completed plenum section sub-assembly.

According to an alternate embodiment of the invention, the plurality of upper steam distribution manifolds for a plurality of cells are combined into a single elevated steam manifold that is suspended from and runs the length of a plurality of condenser modules. According to this embodiment, the lower steam manifold and riser is eliminated, and the elevated steam manifold is fed directly from the turbine exhaust duct which itself is elevated to the level of the elevated steam manifold. The elevated steam manifold feeds steam to the bottom bonnet of each heat exchanger panel at a single location at the center point of the panel.

This new ACC design may be used with tubes having prior art cross-section configuration and area (for example, 200 mm×18-22 mm). Alternatively, this new ACC design may be used with tubes having the design described in US 2017/0363357 and US 2017/0363358 (200 mm×10 mm or less), the disclosures of which are hereby incorporated herein in their entirety.

According to a further alternative embodiment, the new ACC design of the present invention may be used with 100 mm by 5 mm to 7 mm tubes having offset fins.

According to a further embodiment, the new ACC design of the present invention may be used with 200 mm by 5 mm to 7 mm tubes or 200 mm by 17-20 mm tubes, the tubes preferably having “Arrowhead”-type fins arranged at 5-12 fins per inch (fpi), preferably at 9-12 fpi, and most preferably at 9.8 fins per inch.

According to a further embodiment, the new ACC design of the present invention may be used with 120 mm by 5 mm to 7 mm tubes having “Arrowhead”-type fins arranged at 9.8 fins per inch. According to an even further embodiment, the new ACC design of the present invention may be used with 140 mm by 5 mm to 7 mm tubes having “Arrowhead”-type fins arranged at 9.8 fins per inch. While the 120 mm and 140 mm configurations do not produce quite the same increase in capacity as the 200 mm configuration, both the 120 mm and 140 mm configurations have reduced materials and weight compared to the 200 mm design.

For a disclosure of the structure of Arrowhead-type fins discussed above, the disclosure of U.S. application Ser. No. 15/425,454, filed Feb. 6, 2017 is incorporated herein in its entirety.

According to yet another embodiment, the new ACC design of the present invention may be used with tubes having “louvered” fins, which perform approximately as well as offset fins, and are more readily available and easier to manufacture.

The description of fin type and dimension herein is not intended to limit the invention. The tubes of the invention described herein may be used with fins of any type without departing from the scope of the invention.

Accordingly, there is provided according to the invention, a large scale field erected air cooled industrial steam condenser connected to an industrial steam producing facility, having a single or plurality of condenser streets, each condenser street comprising a row of condenser modules, each condenser module comprising a plenum section having a single fan or multiple fans drawing air through a plurality of heat exchanger panels supported in a heat exchanger section, and each heat exchanger panel having a longitudinal axis and a transverse axis perpendicular to its longitudinal axis, each heat exchanger panel having a plurality of tubes, a top bonnet connected to and in fluid communication with a top end of each tube, a bottom bonnet connected to and in fluid communication with a bottom end of at least a subset of said tubes, said bottom bonnet having a single steam inlet; each condenser street including a steam distribution manifold suspended from the heat exchanger section and arranged along an axis that is perpendicular to a longitudinal axis of said heat exchanger panels at a midpoint of said heat exchanger panels and extending a length of said condenser street beneath a plurality of heat exchanger panels, said steam distribution manifold including a cylinder having first and second ends, the cylinder closed at a second end distal from the first end, the cylinder having at its top surface a plurality of connections, each connection adapted to connect to a corresponding single steam inlet.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser wherein each heat exchanger panel comprises a single condenser stage in which all tubes in the heat exchanger panel receive steam from a bottom end of said tubes.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, in which the top bonnet is configured to receive non-condensable gasses, and optionally uncondensed steam, from said condenser tubes, and does not provide steam to said tubes.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein each heat exchanger panel comprises a secondary condenser section, a primary condenser section and a top bonnet connected to and in fluid communication with a top end of each tube in said secondary condenser section and said primary condenser sections, a primary bottom bonnet connected to and in fluid communication with a bottom end of each tube in said primary condenser sections, an internal secondary chamber inside the bottom bonnet connected to and in fluid communication with a bottom end of each tube in said secondary condenser section, said secondary bottom bonnet connected to a top side of said primary bottom bonnet, each said primary bottom bonnet having a single stem inlet.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser wherein each heat exchanger panel comprises two primary condenser sections flanking said secondary section.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein the secondary condenser section is centrally located along said heat exchange panel and flanked at each end by primary condenser sections.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said steam distribution manifold cylinder is attached at a first end to a turbine exhaust duct.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said steam distribution manifold is closed at both ends, and having at a bottom surface a single connection to a steam riser.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein each said heat exchanger panel is independently suspended from a frame of the heat exchanger section by a plurality of flexible hanging supports.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein all of the heat exchange panels in a single heat exchanger section are oriented in the same direction.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein all of the heat exchange panels in a single heat exchanger section are oriented vertically.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein all of the heat exchange panels in a single heat exchanger section are oriented in the same direction, at the same angle relative to vertical.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein all of the heat exchange panels on one side of a single heat exchanger section are inclined relative to vertical in one direction, and all of the heat exchange panels on the other side of the single heat exchanger section are inclined relative to vertical in an opposite direction.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, said plenum section comprising a single fan resting on fan deck framework and drawing air over all of said heat exchange panels in said heat exchanger section.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, said plenum section comprising a plurality of fan deck plates resting on fan deck framework, said fan deck plates each comprising a plurality of fans.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein in each fan draws air across no more than two heat exchange panels.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said flexible hanging supports each comprise a central rod connected at each end to a connection sleeve, and wherein one connection sleeve of each flexible hanging support is connected to said heat exchanger section frame and a second connection sleeve of each flexible hanging support is connected to a tube sheet of said heat exchanger panel.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said plurality of tubes in said heat exchanger panels have a length of 2.0 m to 2.8 m, a cross-sectional height of 120 mm and a cross-sectional width of 4-10 mm.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said tubes have a cross-sectional width of 5.2-7 mm.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said tubes have a cross-sectional width of 6.0 mm.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said plurality of tubes in said heat exchanger panels have fins attached to flat sides of said tubes, said fins having a height of 9 to 10 mm, and spaced at 5 to 12 fins per inch.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, wherein said plurality of tubes in said heat exchanger panels have fins attached to flat sides of said tubes, said fins having a height of 18 mm to 20 mm spanning a space between adjacent tubes and contacting adjacent tubes, said fins spaced at 5 to 12 fins per inch.

There is further provided according to an embodiment of the invention, a method of assembling a large scale field erected air cooled condenser including the steps assembling a heat exchange section at ground level, including a heat exchange section frame and said heat exchanger panels; supporting said heat exchange section at a height from ground sufficient only to suspend a steam distribution manifold section directly beneath and adjacent said heat exchanger panels, assembling a plenum section with fan deck and fan assembly at ground level; raising said assembled heat exchange section and said steam distribution manifold section and placing it atop a corresponding understructure; attaching adjacent steam distribution manifold sections to one-another; and raising said assembled plenum section and placing it atop said heat exchange section.

There is further provided according to an embodiment of the invention, a large scale field erected air cooled industrial steam condenser, optionally connected to an industrial steam producing facility, including: a single or plurality of condenser streets, each condenser street comprising a row of condenser modules, each condenser module comprising a plenum section having single fan or multiple fans drawing air through a plurality of heat exchanger panels supported in a heat exchange section, and each heat exchanger panel having a longitudinal axis and a transverse axis perpendicular to its longitudinal axis, each heat exchanger panel comprising a plurality of condenser tubes and a top bonnet connected to and in fluid communication with a top end of each said plurality of condenser tubes, a bottom bonnet connected to and in fluid communication with a bottom end of each said plurality of condenser tubes, each said bottom bonnet having a single steam inlet; each said condenser street having a single steam distribution manifold suspended from and directly adjacent to a bottom side of said heat exchanger section arranged along an axis that is perpendicular to a longitudinal axis of said heat exchanger panels at a midpoint of said heat exchanger panels and extending a length of said condenser street, said steam distribution manifold comprising a cylinder attached at a first end to a turbine exhaust duct, and closed at a second end distal from said first end, said cylinder having at its top surface a plurality of connections adapted to connect to said bottom bonnet inlets.

