JP7254983B2 - All-secondary air-cooled industrial steam condenser - Google Patents

Description

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

Current finned tubes used in most large-scale field-assembled air-cooled industrial steam condensers (“ACC”) are approximately 11 meters long by 200 mm wide (also referred to as the “air travel length”). A flat tube with semi-circular leading and trailing edges and an internal height (perpendicular to the air travel length) of 18.8 mm is used. The tube wall thickness is 1.35 mm. Fins are brazed to the flat sides on both sides of each tube. The fins are typically 18.5 mm high with a spacing of 11 fins per inch (25.4 mm). The fin surface has a wavy pattern to facilitate heat transfer and aid in fin stiffness. The standard spacing between tube centers is 57.2 mm. The tubes themselves constitute about one-third of the cross sectional face area (perpendicular to the direction of air flow), while the fins occupy approximately two-thirds of the cross section face area. Occupy There is a small space of 1.5 mm between adjacent fin tips. At summer ambient conditions, the maximum steam velocity through the tube can typically be as high as 28 mps, more typically 23-25 mps. These combined tube and fin A-frame designs have been optimized based on tube length, fin spacing, fin height and shape, and air travel length. The finned tubes are typically assembled into heat exchanger tube bundles of 39 tubes per heat exchanger tube bundle, with 10-14 tube bundles per fan arranged together in a single A-frame. It is arranged into two heat exchangers. A fan typically resides at the bottom of the A-frame and forces air upward through the tube bundle. The overall design of the tubes and fins, and the combined air pressure drop of the tubes and fins, is also adapted to the air-moving capacity of large diameter (36 feet (10.9 m)) fans operating at 200-250 horsepower. has been optimized. This optimized arrangement has not changed much across many different manufacturers since the single row oval tube concept was introduced over 20 years ago.

The typical A-frame ACC described above includes both a first stage or "primary" condenser tube bundle and a second stage or "secondary" tube bundle. About 80% to 90% of the heat exchanger tube bundles are first stage or primary condenser tube bundles. Steam enters the top of the primary condenser tube bundle, with condensate and some steam leaving the bottom. The first stage configuration is thermally efficient, but does not provide a means of removing non-condensable gases. To sweep non-condensable gases through the first stage bundle, 10% to 20% of the heat exchanger bundle is configured as a second stage or secondary bundle, typically interspersed between the primary bundles. , draws vapor from the lower condensate manifold. In this arrangement, steam and non-condensable gases travel through the first stage tube bundle as they are drawn to the bottom of the secondary tube bundle. As the gas mixture rises through the secondary tube bundle, the remaining vapor condenses, enriching the non-condensable gases. The top of the secondary bundle is attached to a vacuum manifold that removes non-condensable gases from the system.

Variations to standard prior art ACC arrangements are disclosed, for example, in US Patent Application Publication Nos. 2015/0204611 and 2015/0330709. These specifications show the same finned tubes, but with greatly reduced tube lengths, arranged in a series of smaller A-frames, typically five A-frames per fan. It is Part of the logic is to reduce steam pressure drop, which has a smaller impact on total capacity in summer, but has a greater impact in winter conditions. Another part of this logic is to weld a top steam manifold duct to each of the tube bundles at the factory and ship them together, saving expensive on-site welding operations. The net effect of this arrangement, with factory-installed steam manifolds shipped with the tube bundle, is to shorten the length of the tubes to fit the manifolds in a standard highcube shipping container. Because the tubes are shorter and therefore the total amount of surface area is reduced, the comparative capacity for a standard single A-frame design of similar overall dimensions is reduced by about 3% in summer conditions.

The inventions presented herein are 1) novel tube designs for use in heat exchanger systems, including but not limited to large scale field-assembled industrial steam condensers, and 2) power plants. and novel designs of large-scale field-assembled industrial steam condensers for, etc., both of which significantly increase the heat capacity of the ACC while reducing materials in some configurations. Various aspects and/or embodiments of the invention are presented below.

According to various embodiments of the tube design invention, the tube is 2.044 m long, the cross-sectional dimension of the tube is 100-200 mm wide, preferably 125 mm wide (air movement length), and the cross-sectional height ( perpendicular to the air travel length) is less than 10 mm, preferably 4-10 mm, more preferably 5.0-9 mm, even more preferably 5.2-7 mm, most preferably 6.0 mm high ("outer tube width ) and has fins arranged at 9 to 12, preferably 9.8 fins per inch (25.4 mm). According to a further preferred embodiment, the actual fins are 17-20 mm high, preferably 18.5 mm high and span the space between two adjacent tubes, effectively 9.25 mm of fins are available on each side for each tube.

Producing smaller cross-section tubes (same air travel length but significantly smaller height) is recommended as much as possible to accommodate the enormous steam volumes output by large power plants. There is a need to manufacture tubes with large cross-sections, which directly contradicts the currently prevailing view in the art that the larger the size of the tube, the lower the cost. Although the cost of this arrangement is much higher than prior art tube arrangements, we unexpectedly discovered that the efficiency gains from using lower height tubes (in the most preferred embodiment, 30% higher efficiency compared to tubes), more than making up for the increased cost. This novel tube design may be used in prior art large scale field assembled industrial steam condensers (e.g., as described in the Background section) or the novel tube design described later in this specification. It may be used in conjunction with ACC designs.

Considering now a novel design for a large scale field-assembled industrial steam condenser, the main feature of the invention is that all the tube bundles of the ACC according to the invention are constructed as secondary tube bundles and in which steam is fed from the bottom into upwardly oriented tubes (aligned parallel to the transverse axis of the tube bundle, each tube generally oriented between 25° and 35°, preferably 30° from vertical); Condensate is withdrawn from the tube bundle at the bottom, preferably using an integrated/hybrid manifold that both delivers steam to the tubes and collects condensate from the tubes. According to one embodiment, the integrated/hybrid manifold prevents condensate from going down the steam delivery riser(s) and is instead delivered to the condensate recovery pipe connected to the integrated/hybrid manifold. may be constructed as According to an alternative embodiment, an integrated/hybrid manifold may be constructed so that condensate can descend the steam delivery riser and be removed from the steam delivery duct closer to the ground. The top of the tube is connected to a separate manifold for collecting non-condensable gases. This novel "all secondary" ACC configuration is an A-frame and has two secondary tube bundles joined at the top with a single manifold that collects the non-condensable gases from the tubes, or It may be configured with two non-condensable manifolds, one at the top of each tube bundle.

As used herein, the terms "all secondary" and "no primary" mean that all tube bundles receive water vapor from the bottom, collect condensate at the bottom, and non-condensable gases from the top. Refers to large-scale field-assembled air-cooled industrial steam condensers that deliver. By comparison, the primary tube bundle in a large field-assembled air-cooled industrial steam condenser receives steam at the top, delivers condensate at the bottom, and delivers non-condensable gases at the bottom to a separate secondary condenser. do.

Preferably, however, the ACC of the present invention may be arranged in a V-configuration in which two secondary-only condenser bundles are connected at the bottom with a single integrated steam distribution manifold/condensate recovery manifold and separate of non-condensate collection manifold at the top of each tube bundle.

According to the preferred V-configuration embodiment, the steam manifold resides at the bottom of the tube bundle, so entering the manifold at more than one location reduces the size of the manifold and allows the finned tubes to be slightly longer. . Smaller cross-section tubes described herein (less than 200 mm x 10 mm high, preferably 4-10 mm, more preferably 5.0-9 mm, even more preferably 5.2-7 mm, most preferably 6.0 mm) ), the system exhibits at least a 25%-30% improved performance over the standard ACC arrangement and configuration described above, and the unit can be made a similar amount smaller in terms of floor space. There is

According to a further alternative embodiment, the novel ACC design of the present invention has dimensions of 100mm x, preferably 4-10mm, more preferably 5.0-9mm, even more preferably 5.2-7mm. and most preferably with 6.0 mm tall tubes, with offset fins.

According to a further embodiment, the novel ACC design of the present invention is 120 mm or up to 200 mm x 5 mm to 7 mm with "arrowhead" type fins with 9.8 fins per inch (25.4 mm) may be used in tubes of

According to yet another embodiment, the novel ACC design of the present invention may be used with tubes having "louvered" fins that function much like offset fins and are more readily available and easier to manufacture. Become.

According to preferred and most preferred embodiments of the present invention in combination with the most preferred ACC configuration and most preferred tube dimensions, the ACC of the present invention has the following features and dimensions:
no primary tube bundles, all secondary tube bundles (all tubes receive steam from the bottom, distribute condensate through the bottom, and distribute non-condensable gases out the top);
Pairs of 4, 5 (most preferred) or 6 V-shaped tube bundles per cell/fan cross-section of preferably 125 mm),
tube center-to-center spacing of 20-29 mm (most preferably 24.5 mm);
tube wall thickness 0.7-0.9 mm (most preferably 0.8 mm),
Number of tubes per tube bundle = 40-60 (most preferably 50),
a tube length of 1,700 to 2,400 mm (most preferably 2,044 mm);
arrowhead fins spanning between adjacent tubes and thermally connected to both tubes (preferred but not a requirement);
fin height 17-19 (most preferably 18.5 mm (effective height 9.25 mm per side of tube));
Fins with an air displacement length of 95mm to 195mm, most preferably 120mm.

According to this most preferred embodiment, the total area of the tube bundle surface for a prior art ACC with identical total fan power, steam volume and thermal conditions is 79%; The area is 79% of that of the prior art ACC with the same total fan output, steam volume and thermal conditions.

Additionally, the ACC design of the present invention may be easier to install and may require less overall space within the power plant.

1 is a perspective view of the heat exchange portion of a prior art large scale field assembled air cooled industrial steam condenser; FIG. 1 is an enlarged partially exploded view of the heat exchange portion of a prior art large scale field assembled air cooled industrial steam condenser showing the orientation of the tubes relative to the steam distribution manifold; FIG. 1 is a perspective view of a heat exchange portion of a large scale field assembled air cooled industrial steam condenser (“ACC”) according to a first embodiment of the present invention; FIG. 1 is a perspective view of a heat exchange portion of a large scale field assembled air cooled industrial steam condenser (“ACC”) according to a second embodiment of the present invention; FIG. FIG. 4 is a perspective view of the heat exchange portion of a large scale field assembled air cooled industrial steam condenser (“ACC”) according to a third embodiment of the present invention; FIG. 4 is a perspective view of a heat exchange portion of a large scale field assembled air cooled industrial steam condenser (“ACC”) according to a fourth embodiment of the present invention; 1 is a cross-sectional perspective view of a prior art ACC tube and fin; FIG. FIG. 2 is a perspective view of a mini-tube and fins according to one embodiment of the invention; FIG. 10 is a perspective view of a mini-tube and fins according to another embodiment of the invention; 1 street of a large scale field-assembled air-cooled industrial steam condenser according to an embodiment of the invention having the V-shaped secondary heat exchange tube bundle only pair arrangement shown in FIG. 4A. is a side view of the. 9 is an end view of the large scale field assembled air cooled industrial steam condenser shown in FIG. 8. FIG. 9 is a top view of the large field assembled air cooled industrial steam condenser shown in FIG. 8 showing one turbine exhaust duct divided into six longitudinal steam headers (six streets) of six cells each; FIG. . 1 is a perspective view of a secondary condenser finned tube bundle in accordance with one embodiment of the present invention; FIG. 12 is a perspective photograph of the secondary condenser finned tube bundle depicted in FIG. 11; FIG.

(A-frame ACC with all secondary bundles)

With reference to FIG. 2, the tubes 2 are arranged in a secondary tube bundle 4 . The longitudinal axis of tubes 2 is aligned parallel to the transverse axis of the tube bundle, with each tube generally oriented between 25° and 35°, preferably 30° from vertical. An integrated vapor distribution/condensation recovery manifold 6 is attached to the bottom of each of the two secondary tube bundles 4 which are joined at their tops in an A-frame configuration. Steam is distributed to the tubes 2 via the integrated steam distribution/condensate recovery manifold 6 where as the steam condenses it forms condensate in the tubes 2 and down the tubes 2 to the integrated steam distribution/condensate recovery manifold 6 . flow into A single non-condensate collection manifold 8 is attached to the top of both tube bundles 6 to collect the non-condensable gases that migrate to the top of the tubes 2 . Steam is supplied from steam duct 10 via riser 12 to integrated steam distribution/condensate recovery manifold 6 . Condensate that collects in the integrated steam distribution/condensate recovery manifold 6 is carried away from the ACC in condensate recovery pipes 14 .

Figure 3 shows an embodiment very similar to that of Figure 2, but each tube bundle 4 is attached at its top to a dedicated non-condensate collection manifold.

(V-shaped ACC with all secondary bundles)

With reference to FIGS. 4A and 4B, tubes 2 are arranged in secondary tube bundles 4 . The longitudinal axis of tubes 2 is oriented parallel to the transverse axis of the tube bundle, with each tube generally oriented between 25° and 35°, preferably 30° from vertical. Attached to the bottom of the two secondary bundles 4 is an integrated steam distribution/condensate recovery manifold 6 joined at an angle of 55° to 65°, preferably 60° in a V-configuration. Steam is distributed to tubes 2 via an integrated steam distribution/condensate collection manifold 6 where the steam condenses to form condensate in tubes 2 and down tubes 2 to an integrated steam distribution/condensate collection manifold. Go inside 6. A non-condensate collection manifold 8 is attached to the top of both tube bundles 6 to collect non-condensable gases that migrate to the top of the tubes 2 . Steam is supplied from steam duct 10 via riser 12 to integrated steam distribution/condensate recovery manifold 6 . Condensate collected in the integrated steam distribution/condensate collection manifold 6 is carried away from the ACC in condensate collection pipes 14 .

The novel ACC design described above is approximately 11 meters long, 200 mm wide (or "air movement length"), has semi-circular leading and trailing edges, and has an internal height (perpendicular to the air movement length) of Fins brazed to both flat sides of each tube, typically 18.5 mm high and 1 inch (25.4 mm ) may also be used with any prior art tube, including the tube shown in FIG. However, according to a more preferred embodiment, the novel ACC design of the present invention has the following features and dimensions:
no primary tube bundles, all secondary tube bundles (all tubes receive steam from the bottom, distribute condensate from the bottom, and distribute non-condensable gases from the top out);
4, 5 (most preferred) or 6 V-shaped tube bundle pairs per cell/fan;
cross-section of tube outer diameter 4-10 mm (preferably 5-7 mm, most preferably 6.0 mm) x 100-200 mm (most preferably 125 mm);
tube center spacing of 20 to 29 mm (most preferably 24.5 mm);
Tube wall thickness 0.7-0.9 mm (most preferably 0.8 mm)
Number of tubes per tube bundle = 40-60 (most preferably 50)
Tube length 1,700-2,400 mm (most preferably 2,044 mm)
Arrowhead fins spanning between adjacent tubes and thermally connected to both tubes (preferred but not a requirement)
fin height 18.5 mm (effective height 9.25 mm per side of tube),
Air moving length fins 95mm to 195mm, most preferably 120mm.
This preferred embodiment provides a 25-30% capacity increase for a single cell at constant fan power over prior art A-frame designs using standard tubes. .

8-10 are representative large scale field assembled air cooled industrial steam condensers according to embodiments of the present invention having only the pair of V-shaped secondary heat exchange tube bundles shown in FIG. 4A. indicates The apparatus shown in FIGS. 8-10 is a 36 cell (6 streets by 6 cells) ACC and is the most preferred embodiment of 5 tube bundle pairs per cell, but the present invention may be used with any size ACC. and any number of tube bundle pairs per cell may be used.

Claims (11)

An all secondary tube bundle large scale field assembled air cooled industrial steam condenser connected to an industrial steam production facility comprising:
a rectangular array of air-cooled condensate cells arranged in a plurality of rows, each of said plurality of rows comprising a plurality of said air-cooled condensate cells;
Each air-cooled condensate cell includes a plurality of pairs of condenser tube bundles arranged in an A-shaped or V-shaped configuration, each condenser tube bundle being a finned flattened unit fitted adjacent to each other. comprising a single row of one-channel tubes, each of said condenser tube bundles oriented such that the longitudinal axis of said finned flattened tubes is positioned at an angle of 55° to 65° from the horizontal;
Each condenser tube bundle is attached at a bottom end for delivering steam to the bottom of said finned flattened single channel tubes, and cooling within said finned flattened single channel tubes from said steam. an integrated steam distribution-condensate recovery manifold extending along the length of said condenser tube bundle configured for both collecting condensate that forms;
Each condenser tube bundle is attached at its top end and extends along the length of said condenser tube bundle parallel to each of said integrated steam distribution-condensate recovery manifolds and is non-removable from said steam. comprising a non-condensate recovery manifold configured to recover condensable gases;
Each row of air-cooled condensate cells includes a steam duct extending below the midpoint of the condenser tube bundles in said row, said steam ducts each extending longitudinally of said condenser tube bundles in said row. having a longitudinal axis perpendicular to the axis and connected to the bottom surface of each integrated steam distribution-condensate recovery manifold of said condenser tube bundles in said row;
An all secondary bundle large scale air cooled industrial steam condenser where all of the steam delivered to the condenser tube bundle is delivered from the integrated steam distribution-condensate recovery manifold. 2. The field assembled all secondary tube bundle of claim 1, wherein all of the condensate recovered from said finned flat single channel tubes is recovered within said integrated steam distribution-condensate recovery manifold. Air-cooled industrial steam condenser. 2. The large scale field assembled air cooled industrial steam recovery all secondary tube bundle of claim 1 wherein said longitudinal axis of said finned flattened single channel tube is disposed at an angle of 60[deg.] from horizontal. water vessel. The all-secondary tube bundle large scale field assembled air-cooled industrial steam according to claim 1, wherein said finned flattened single channel tube has a cross-sectional width of 125 mm and a cross-sectional height of 5.2-7 mm. condenser. 2. The all-secondary tube bundle large scale field assembled air cooled industrial steam condensate according to claim 1, wherein said finned flattened single channel tube has a cross-sectional width of 125 mm and a cross-sectional height of 6.0 mm. vessel. The finned flattened single channel tube has fins attached to the flat side of the tube, the fins having a height of 10 mm and 9-12 fins per inch (25.4 mm). 2. The all-secondary tube bundle large scale field-assembled air cooled industrial steam condenser of claim 1 having a spacing of . The all-secondary tube bundle large scale field assembled air cooled industrial steam condensate according to claim 1, wherein said finned flattened single channel tube has a cross-sectional width of 200 mm and a cross-sectional height of 17-20 mm. vessel. 2. The all-secondary tube bundle large scale field assembled air cooled industrial steam condensate according to claim 1, wherein said finned flattened single channel tube has a cross-sectional width of 200 mm and a cross-sectional height of 18.8 mm. vessel. The large scale field assembled air cooled industrial steam condensate all secondary tube bundle of claim 1 wherein said finned flattened single channel tubes have a cross-sectional width of 125mm and a cross-sectional height of 4-10mm. vessel. The all-secondary tube bundle large-scale field-assembled air-cooled industrial steam condenser of claim 1, wherein said finned flattened single-channel tubes have a length of 1700 mm to 2400 mm. The all secondary tube bundle large scale field assembled air cooled industrial steam condenser of claim 1 comprising 40 to 60 of said finned flattened single channel tubes.

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