AIR-COOLED CONDENSER APPARATUS AND METHOD

Abstract

The present invention relates to an air-cooled condenser apparatus for condensing a steam flow exiting a turbine from for example a power plant. The air-cooled condenser apparatus comprises a series of condenser modules, each module having a series of compact delta-type heat exchanger units and a series of fans. The air-cooled condenser apparatus further comprises a series of independent frame structures FRS(m) wherein the number of frame structures has a lower limit depending on the number of modules. The invention further relates to a method for manufacturing an air-cooled condenser apparatus comprising steps of manufacturing the delta-type heat exchanger units in the factory, placing the units in a container for transportation and erecting the air-cooled condenser apparatus at a site of installation.

Claims

1. An air-cooled condenser apparatus for condensing a steam flow from a steam turbine wherein the air-cooled condenser apparatus is erected along a vertical axis Z perpendicular to a floor level including two orthogonal axes X and Y perpendicular to the axis Z, said air-cooled condenser apparatus comprising: a series of condenser modules ACCM(i) with i=1 to NMOD and 1NMOD, each condenser module ACCM(i) of said series of condenser modules including: a) a series HEXU(j) of delta-type heat exchanger units with j=1 to UN and UN=2 or UN=3, forming a row of UN delta-type heat exchanger units extending along a direction parallel with said axis X, and wherein each delta-type heat exchanger unit of said series HEXU(j) includes: a first set of parallel tubes and a second set of parallel tubes that are inclined with respect to said vertical axis Z and are positioned so as to have an opening angle between the first set and the second set of parallel tubes, the opening angle in a range 4565, and wherein the tubes of said first set and second set of parallel tubes have a tube length TL in a range of 1.5 m<TL<2.5 m, and said tubes include fins, a top duct extending in a direction parallel to said axis Y and connected to an upper end of each tube of said first set of parallel tubes and connected to an upper end of each tube of said second set of parallel tubes, a first steam/condensate manifold extending in a direction parallel to said axis Y and connected to a lower end of each tube of said first set of parallel tubes, and a second steam/condensate manifold extending in a direction parallel to said axis Y and connected to a lower end of each tube of said second set of parallel tubes, said first steam/condensate manifold and said second steam/condensate manifold have a length PL that is in a range of 8.0 m<PL<13.7 m, and b) a series of fans FAN(k) with k=1 to FN and with 2FN4, and wherein the fans FAN(k) are aligned along an axis parallel with the Y axis and configured to generate an air flow through each delta-type heat exchanger unit of said series HEXU(j), and a support structure configured for positioning the delta-type heat exchanger units of each of the condenser modules ACCM(i) at a height H1, measured along the Z axis, that is equal to or larger than four meter above said floor level.

2. An air-cooled condenser apparatus according to claim 1, wherein said support structure includes a series of independent frame structures FRS(m) with m=1 to NFR, wherein said series of independent frame structures is configured for supporting a total number NTOT=UNNMOD of delta-type heat exchanger units, and wherein the number NFR of said independent frame structures is in the range Ceiling(NMOD/3)NFRNMOD.

3. An air-cooled condenser apparatus according to claim 2, wherein said series of independent frame structures FRS(m) includes one or more frames of a model A and/or one or more frames of a model B and/or one or more frames of a model C, and wherein said frame of model A is configured to support the series HEXU(j) of delta-type heat exchanger units of one condenser module, said frame of model B is configured to support the series HEXU(j) of delta-type heat exchanger units of two condenser modules, and said frame of model C is configured to support the series HEXU(j) of delta-type heat exchanger units of three condenser modules.

4. An air-cooled condenser apparatus according to claim 1, wherein each condenser module ACCM(i) of said series of condenser modules includes a box-shaped upper frame structure attached to said series of independent frame structures FRS(m), and wherein said box-shaped upper frame structure includes a fan deck located at height H2 with respect to said floor level and wherein H27 m, and wherein said fan deck is configured to support said series of fans FAN(k) so as to generate, when in operation, an induced air draft through the delta-type heat exchanger units of the module.

5. An air-cooled condenser apparatus according to claim 2, wherein each independent frame structure of said series of independent frame structures FRS(m) includes means for attaching one or more of said series of fans FAN(k) at a height H3 with respect to said floor level and wherein H1>H32 m.

6. An air-cooled condenser apparatus according to claim 1, wherein, for each of the delta-type heat exchanger units of each condenser module, said first set of parallel tubes includes a first group of primary tubes and a first group of secondary tubes and said second set of parallel tubes includes a second group of primary tubes and a second group of secondary tubes, and wherein said top duct includes: a first top duct section having an entrance opening on one end to receive steam and a cover on the other end, and wherein the first top duct section (2a) is connected to said first group of primary tubes and to said second group of primary tubes, and a second top duct section including an exit opening for evacuating non-condensable gases and/or non-condensed steam, and wherein said second top duct section is connected to said first group of secondary tubes and to said second group of secondary tubes.

7. An air-cooled condenser apparatus according to claim 1, wherein the top duct of each delta-type heat exchanger unit includes an entrance opening for receiving steam, and wherein the entrance opening has a cross-sectional area S in the range of 0.12 m.sup.2S0.5 m.sup.2.

8. An air-cooled condenser apparatus according to claim 1, further including a main steam duct elongated along an axis parallel with said axis X, and wherein one end of each top duct of each delta-type heat exchanger unit of each module is connected with said main steam duct.

9. A method for manufacturing an air-cooled condenser apparatus, the method comprising: a) manufacturing a plurality of delta-type heat exchanger units in a factory by, for each delta-type heat exchange unit: providing a top duct, providing a first steam/condensate manifold and a second steam/condensate manifold, each steam/condensate manifold having a length PL wherein 8.0 m<PL<13.7 m, providing a first set and a second set of tubes, each tube of said first set and said second set of tubes has a length TL wherein 1.5 m<TL<2.5 m, and each tube includes fins, connecting a lower end of the first set of tubes to the first steam/condensate manifold and connecting an upper end of the first set of tubes to said top duct, and connecting a lower end of the second set of tubes to the second steam/condensate manifold and connecting an upper end of the second set of tubes to the top duct, so as to form an opening angle between the first set of tubes and the second set of tubes wherein 4565, b) transporting the plurality of delta-type heat exchanger units from the factory to an installation site where the air-cooled condenser apparatus is to be operated, and c) assembling said air cooled condenser apparatus at said installation site by: installing a support structure for supporting said plurality of delta-type heat exchanger units, and forming one or more condenser modules by performing, for each condenser module: i) placing a number UN, with UN2, of the delta-type heat exchanger units on the support structure so as to form a row of UN delta-type heat exchanger units, and ii) installing a number of fans FN, with FN1, under or above the row of UN delta-type heat exchanger units.

10. A method according to claim 9, wherein said number UN of delta-type heat exchanger units is equal to 2 or 3 and wherein said number of fans FN is within 2FN4.

11. A method according to claim 10, wherein the installing FN fans under or above the row of UN delta-type heat exchanger units includes aligning the FN fans along an axis parallel with the top ducts of the delta-type heat exchanger units of said row of UN delta-type heat exchanger units.

12. A method according to claim 9, wherein the transporting includes: providing one container per delta-type heat exchanger unit to be transported, and placing the delta-type heat exchanger units to be transported in the containers such that each delta-type heat exchanger unit rests with its first and second steam/condensate manifold on a floor level of the container or on a transportation support located on the floor level of the container.

13. A method according to claim 9, further including manufacturing frame structures of one or more models, wherein each model is designed for supporting a given number of delta-type heat exchanger units.

14. A method according to claim 9, wherein the forming one or more condenser modules includes, for each condenser module: providing a box-shaped upper frame structure including a fan deck, and placing said box-shaped upper frame structure on top of said support structure, and wherein the installing one or more fans includes mounting the one or more fans on the fan deck.

15. A method according to claim 9, wherein the manufacturing a plurality of delta-type heat exchanger units in a factory includes attaching one or more strengthening elements to the delta-type heat exchanger units.

16. A method according to claim 9, wherein said first steam/condensate manifold and said second steam/condensate manifold are configured for supporting a weight resulting from said top duct, said first set of tubes and/or said second set of tubes such that the manufactured delta-type heat exchanger unit is a self-supporting structure that can rest on said first and second steam/condensate manifolds.

17. A modular air-cooled condenser apparatus for condensing a steam flow from a steam turbine including one or more condenser modules, each of the condenser modules comprising: a) two or three adjacently positioned delta-type heat exchanger units, wherein each of the two or three delta-type heat exchanger units includes: a first set and a second set of parallel tubes for condensing steam, wherein the tubes have a tube length TL in a range of 1.5 m<TL<2.5 m, and wherein the first set and second set of parallel tubes are configured such that an opening angle in a range 4565 is formed between the first set and the second of parallel tubes, a top duct for supplying steam, wherein the top duct is connected to an upper end of each of the tubes of the first set and second set of parallel tubes, a first steam/condensate manifold connected to a lower end of each tube of the first set of parallel tubes, and a second steam/condensate manifold connected to a lower end of each tube of the second set of parallel tubes, and wherein the first and second steam/condensate manifold have a length PL that is in a range of 8.0 m<PL<13.7 m, and b) two to four fans aligned along an axis so as to form a single row of fans, wherein the single row of fans is configured to generate an air flow through each of the two or three adjacently positioned delta-type heat exchanger units of the condenser module.

18. A modular air-cooled condenser apparatus according to claim 17, further including a modular support structure configured for positioning the two or three delta-type heat exchanger units of each of the condenser modules at a given height H1, that is equal to or larger than four meters above a floor level, and wherein the modular support structure includes a series of independent frame structures FRS(m) with m=1 to NFR, and wherein the number NFR of independent frame structures is in the range Ceiling(NMOD/3)NFRNMOD, wherein NMOD is the number of modules of the modular air-cooled condenser apparatus.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0085] These and further aspects of the invention will be explained in greater detail by way of example and with reference to the accompanying drawings in which:

[0086] FIG. 1A shows a front view of a delta-type heat exchanger unit according to the invention;

[0087] FIG. 1B shows a perspective view of the delta-type heat exchanger unit of FIG. 1A;

[0088] FIG. 2 shows a cross section of a single condenser module according to the invention, supported by one frame structure;

[0089] FIG. 3 shows a cross section of another single condenser module according to the invention, supported by one frame structure;

[0090] FIG. 4 shows a cross section of three condenser modules supported by two frame structures;

[0091] FIG. 5a shows a top view of an exemplary air-cooled condenser apparatus according to the invention, comprising seven condenser modules supported by four frame structures;

[0092] FIG. 5b shows a side view of the apparatus of FIG. 5a;

[0093] FIG. 6 shows side views of various examples of air-cooled condenser apparatuses according to the invention, comprising various numbers of modules and various numbers of frame structures;

[0094] FIG. 7 shows side views of other examples of air-cooled condenser apparatuses according to the invention comprising various numbers of modules and various numbers of frame structures;

[0095] FIG. 8 shows a cross section of an air-cooled condenser wherein each condenser module comprises three delta-type heat exchanger units;

[0096] FIG. 9A shows a delta-type heat exchanger unit comprising one or more strengthening beams;

[0097] FIG. 9B shows a delta-type heat exchanger unit comprising a cover plate;

[0098] FIG. 10 shows a schematic representation of a delta-type heat exchanger unit wherein the condenser panels are formed by three layers of tubes.

[0099] FIG. 11 shows a perspective view of a delta-type heat exchanger unit wherein the top duct comprises a first and a second section and wherein the condenser panels comprise primary and secondary tubes;

[0100] FIG. 12 shows a perspective view of a delta-type heat exchanger unit wherein a first manifold section is separated from a second manifold section.

[0101] The figures are not drawn to scale. Generally, identical components are denoted by the same reference numerals in the figures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0102] The present invention has been described in terms of specific embodiments, which are illustrative of the invention and not to be construed as limiting. More generally, it will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and/or described hereinabove. The invention resides in each and every novel characteristic feature and each and every combination of characteristic features. Reference numerals in the claims do not limit their protective scope. Use of the verbs to comprise, to include, to be composed of, or any other variant, as well as their respective conjugations, does not exclude the presence of elements other than those stated. Use of the article a, an or the preceding an element does not exclude the presence of a plurality of such elements.

[0103] According to a first aspect of the invention an air-cooled condenser apparatus for condensing a steam flow from a power plant is provided. Such an air-cooled condenser apparatus comprises a series of condenser modules ACCM(i) with i=1 to NMOD and 1NMOD. As shown on FIGS. 4 and 5, the air-cooled condenser apparatus is positioned on a floor level plane comprising two orthogonal axes X and Y and the apparatus is further erected in height along an axis Z perpendicular to the floor level. There is no limitation on the number of modules NMOD of the air-cooled condenser apparatus, NMOD can be any value 1. The number is defined by the amount of steam flow to be condensed. For example, a small air-cooled condenser apparatus can have 5 modules, other larger apparatuses can have 10 condenser modules, other can have 30 condenser modules or more. Generally, the number of modules NMOD is equal or larger than two.

[0104] Each condenser module according to the invention comprises a series HEXU(j) of so-called delta-type heat exchanger units (1) with j=2 to UN, and UN is equal to two or three. The series HEXU(j) is forming a row of UN delta-type heat exchanger units. This row is extending along a direction parallel with the axis X, as illustrated in FIGS. 2, 3,4 and 8. In other words, as shown on these figures, for each module, the delta-type heat exchangers are positioned adjacent to each other.

[0105] An example of a delta-type heat exchanger unit according to the invention is shown in more detail in FIG. 1A and FIG. 1B. Such a delta-type heat exchanger 1 comprises a top duct 2, a first 5 and a second 6 steam/condensate manifold extending in a direction parallel to the axis Y, a first set of parallel tubes 40 and a second set of parallel tubes 41 that are forming, respectively, a first condenser panel 3 and a second condenser panel 4. The tubes are schematically indicated on FIG. 1B. The first 40 and second 41 set of parallel tubes are inclined with respect to the vertical axis Z. As shown on FIG. 1B, the first and second steam/condensate manifold have a length PL along a direction parallel with the axis Y. In FIG. 4, an example of an air-cooled condenser apparatus is shown having three modules and wherein each module comprises two delta-type heat exchanger units.

[0106] The delta-type heat exchanger units of the air-cooled condenser according to the invention is characterized in that the tube length TL is comprised in a range of 1.5 m<TL<2.5 m and the length PL of the first and second steam/condensate manifold is comprised in a range of 8.0 m<PL<13.7 m. The length PL and the tube length TL are indicated on FIG. 1B.

[0107] The tube length TL has to be construed as the distance between the location where the upper end of the tube is connected to the top duct and the location where the lower end of the tube is connected to a steam/condensate manifold.

[0108] The length PL of the first and second steam/condensate manifold has to be construed as the distance of the steam/condensate manifold measured in a direction parallel with the Y axis as shown on FIG. 1B, this corresponds to the distance from the first tube to the last tube of the first set of parallel tubes or the distance from first to the last tube of the second set of parallel tubes. This typically corresponds to the distance between the locations where the first tube and the last tube of for example the first set of parallel tubes are connected to the first steam/condensate manifold. This length PL also corresponds to a panel length of the panel that is formed by the set of parallel tubes. Preferably, the length of the top duct 2 is also comprised in the range between 8.0 m and 13.7 m. In practice, as the parallel tubes are connected both to the top duct and to the steam/condensate manifolds, the length of the top duct and the length of the steam/condensate manifolds is the same or closely the same. In some embodiments, as shown on FIG. 5A, the length of the top duct can be slightly longer than the length of the steam/condensate manifolds in order to for example facilitate the installation of a bellow 30 on the entrance side of the top duct to be connected to the main steam duct 20. The main steam duct 20 is a duct elongated along an axis parallel with the axis X as shown on FIGS. 5A, 5B, 6 and 7.

[0109] Generally, the top duct 2 has a tubular shape. The delta-type heat exchanger units HEXU(j) of each condenser module are oriented such that their top ducts 2 are oriented in parallel so as to form a row of UN delta-type heat exchanger units. For example the single condenser module ACCM(1) shown in FIG. 2 comprises a row of two delta-type heat exchanger units wherein the two top ducts are oriented in parallel. Top ducts oriented in parallel has to be construed as an orientation wherein the central axes of the tubular top ducts are oriented in parallel. For example, as shown on FIG. 5A, the top ducts 2 of each of the seven modules are oriented in parallel with the Y axis. As shown on FIGS. 2 to 8, the rows of adjacent delta-type heat exchanger units are extending in a direction parallel with the axis X.

[0110] In embodiments according to the invention, the first set and a second set of parallel tubes are inclined with respect to the vertical axis Z so as to have an opening angle within a range 4565. This opening angle is shown on FIG. 1A and FIG. 10. A delta-type heat exchanger with such an opening angle and dimensions as discussed above can enter the door opening of standard container (e.g. a door opening of 2.3 m).

[0111] The opening angle is measured as shown on FIG. 1A as the angle between two center planes 32 of the first condenser panel 3 and second condenser panel 4. The center planes 32 are shown as a dotted line on FIG. 1A and FIG. 10. In case the first condenser panel and the second condenser panel each comprise only one layer of parallel tubes (FIG. 1A), then the center plane 32 corresponds to a plane going through the center lines of the tubes of the panel. In case the first and second condenser panel are formed by multiple layers of parallel tubes, then the center plane is defined as the plane going through the center of the layers. This is schematically illustrated in FIG. 10 where, as an example, the first and second condenser panel comprise three layers of parallel tubes.

[0112] Each condenser module according to the invention comprises a series of fans FAN(k) with k=1 to FN and with 2FN4, and wherein the fans FAN(k) are aligned along an axis parallel with the Y axis. An example of an air-cooled condenser apparatus comprising seven modules wherein each module comprises a series of fans FAN(k) having two fans, FAN(1) and FAN(2), that are oriented along a axis parallel with the Y axis is shown in FIG. 5A. The orientation of the fans along an axis parallel with the Y axis has to be construed as an orientation wherein the central rotation point of each of the fans lies on a line that is parallel with the Y axis.

[0113] A condenser module ACCM(i) according to the invention has to be construed as a configuration of a number UN of heat exchanger units HEXU(j) and a number FN of fans FAN(k). The modules are designed such that the fans FAN(k) provide the necessary air circulation through the UN number of heat exchanger units.

[0114] For example, in FIG. 5A and FIG. 5B, seven condenser modules are shown and each condenser module ACCM(i) comprises two heat exchanger units arranged in a row and each condenser module comprises two fans, FAN(1) and FAN(2), aligned along an axis parallel with the axis Y. In other words, in this example, the two fans FAN(1) and FAN(2) are forming a single row of fans for providing an air flow through the two delta-type heat exchangers of the module.

[0115] In FIG. 8, an example is shown of an air-cooled condenser apparatus comprising two modules, ACCM(1) and ACCM(2), wherein each module comprises three delta-type heat exchanger units. Each of the two modules shown on FIG. 8 comprises two fans, FAN(1) and FAN(2), forming a single row of fans aligned along an axis and configured to generate an air flow through the three delta-type heat exchangers of the module. In other words, in the embodiments according to the invention, for each module ACCM(i) comprising a series of delta-type heat exchanger units HEXU(j) with j=1 to UN, a row of fans FAN(k) with k=1 to FN is provided to generate an air flow through each of delta-type heat exchangers of the module.

[0116] The heat exchanger units are supported by independent frame structures FRS(m). Typically, as shown on FIG. 2 and FIG. 3, the heat exchanger units have to be positioned at a height H1 from a floor level. In FIG. 2 and FIG. 3 the floor level is parallel with the axis X and Y and the height is defined with respect to the floor level and measured along the axis Z. Typically, to allow sufficient air supply and air circulation, the heat exchanger units are to be installed at a height H1 between 4 and 8 m from the floor level. As shown on FIG. 2 and FIG. 3, delta-type heat exchanger units rest with their steam/condensate manifolds on the independent frame structures. Hence, the height H1 corresponds to the height where the steam/condensate manifolds rest on the independent frame structures.

[0117] In embodiments, as shown for example on FIG. 2 and FIG. 3, the frame structures FRS(s) comprise supporting beams 12 positioned horizontally at a height H1>4 m with respect to the floor level. Supporting legs 11 are attached to the supporting beams 12 for holding the supporting beams at the height H1. The delta-type heat exchangers rest with their first 5 and second 6 steam/condensate manifolds on the supporting beams 12.

[0118] The air-cooled condenser apparatus according to the invention comprises a series of independent frame structures FRS(m) with m=1 to NFR configured for supporting the total number NTOT=UNNMOD of delta-type heat exchanger units (1). Those frame structures position the heat exchangers at a height H1>4 m with respect to the floor level. The number of frame structures NFR according to the invention has a lower limit and an upper limit, defined as Ceiling(NMOD/3)NFRNMOD. The ceiling function has been discussed above.

[0119] An independent frame structure according to the invention has to be constructed as a frame structure that is self-standing or self-resting on the floor level, i.e. it comprises resting means such as legs that can be attached to the floor level.

[0120] By defining a lower limit for the number of frame structures, a number of standard frame structures can be designed that can used for all air-cooled condenser apparatuses according to the invention. Examples of standard type frame structures are a model A, a model B and model C wherein model A is configured to support the heat exchangers of one module, model B is configured to support the heat exchangers of two modules and model C is configured to support the heat exchangers of three modules. One can develop either only one model i.e. model A or one can develop model A and model B or one can develop the three models A,B,C. Hence, due to the definition of the number of frames FRS(m), only one or two or three standard frame structures need to be designed to support any total number NTOT=UNNMOD of heat exchanger units.

[0121] In table 1, the number of frames structures NFR according to the invention is given for a number of configurations of air-cooled condenser apparatuses having a different number of condenser modules (NMOD). In the second column, the number of NFR of frames according to the invention is given and, in between brackets, a few examples of favorable frame combinations with standard frames A, B or C are given. If the air-cooled condenser apparatuses are rather small and require less than 5 modules, only needs a single frame structure model A is to be designed. For five or more modules, it is practically better to design two type of frames structures, model A and model B. As shown in table 1, with for example two standard frame structures A and B, an air-cooled condenser apparatuses with up to 10 modules can be built. For more than 10 modules, with two standard frames one can continue to find the combinations needed but for practical reasons, to reduce the total number of frame structures, an additional third model C is recommended if more than 10 modules need to be installed.

TABLE-US-00001 TABLE 1 Possible number of frames NFR for a given number NMOD of modules. #Modules #Frame structures NMOD Ceiling(NMOD/3) NFR NMOD 1 1 (1 A) 2 1 (1 B) or 2 (2 A) 3 1 (1 C) or 2 (1 A + 2 B)or 3 (3 A) 4 2 (2 B) or 3 (2 A + 1 B) or 4 (4 A) 5 2 (1 B + 1 C)or 3 (2 B + 1 A) or 4 or 5 6 2 (2 C) or 3 (3 B) or 4 or 5 or 6 7 3 (2 C + 1 A) or 4 (3 B + 1 A)) or 5 or 6 or 7 8 3 (2 C + 1B)or 4 (4 B)or 5 or 6 or 7 or 8 9 3 (3 C) or 4 (4 B + 1 A) or 5 or 6 or 7 or 8 or 9 10 4 (3 C + 1 A) or 5 (5 B) or 6 or 7 or 8 or 9 or 10

[0122] The frame structures FRS(m) are typically open frame steel structures comprising beams.

[0123] In FIG. 6 and FIG. 7 show a number of configurations of air-cooled apparatuses according to the invention. These apparatuses comprise modules having two delta-type condenser units and the condensation capacity of the apparatus is increased by adding more condenser modules. Support structures FRS(i) as discussed above are provided to support the total number of delta-type heat exchangers. In FIG. 6, five examples are shown of configurations that comprise support structures of the model A and/or B. In FIG. 7, three examples of configurations comprising one or more support structures of model C are shown. The top panel shows seven modules supported by three frame structures, two of model C and one of model A. The middle panel of FIG. 7 shows eight modules supported by three frame structures, two of model C and one of model B. The lower panel shows nine condenser modules supported by three support structures of model C. In FIG. 8, an example of an apparatus comprising two modules wherein each module comprises three delta-type heat exchangers is shown. In this example, the two modules are supported by two independent frame structures of model A.

[0124] As discussed above, the first 3 and a second 4 condenser panels comprise parallel tubes having a tube length TL. As known in the art, a condenser panel, also named tube bundle, comprises either a single row of tubes or multiple rows of tubes. The tubes preferably comprise fins to improve the heat exchange.

[0125] In an embodiment according to the invention, current state of the art single row tubes are used for manufacturing the condenser panels. The cross sections of these single layer tubes can have for example a rectangular shape or alternatively an elliptical shape. In other embodiments, multiple layer round core tubes can be placed in parallel for forming the tube bundles or condenser panels.

[0126] An exemplary embodiment of an air-cooled condenser apparatus according to the invention is shown on FIG. 5A and FIG. 5B. This exemplary air cooled condenser apparatus according to the invention comprises seven condenser modules and has the same steam condensation capacity as two prior art large scale A type condenser apparatuses. In this example shown on FIG. 5A and FIG. 5B, each condenser module comprises two delta heat exchanger units and two fans aligned along an axis parallel with the direction of the two top ducts of the two delta heat exchanger units. The first 6 modules are supported by three support structure of the second model supporting two modules and the last module is supported by a support structure of the first model supporting one module.

[0127] The footprint (lengths along the X and Y axes) of the 7 modules according to the invention is about the same as the two-module prior art A-type condenser apparatus. The total exchange surface is also about the same, reflecting that the condensation capacity of the 7 modules according to the invention is equivalent to two A-type modules.

[0128] In embodiments according to the invention, the delta-type heat exchanger unit (1) comprises a top duct 2 with a circular entrance opening for receiving steam. Typically the circular entrance opening has an inner diameter in the range 0.4 m<<0.8 m. In other embodiments, the opening of the top duct can have any other geometrical shape such as for example an elliptical entrance opening. In general, at the entrance opening, the top duct has a cross-sectional area S in the range of 0.12 m.sup.2S0.5 m.sup.2. In some other embodiments, the top duct can have a conical shape.

[0129] In embodiments, a bellow 30 is attached to each top duct 2 of each delta-type heat exchanger unit as illustrated in FIG. 5A. This bellow allows for a flexible connection of the top duct with the main steam duct 20. Typically, the main steam duct 20 that brings steam from for example a turbine to the air-cooled condenser apparatus is supported by a main steam duct support 21 as shown on FIG. 5B.

[0130] According to embodiments of the invention, as shown in FIG. 2 to 4, each condenser module ACCM(i) of the series of condenser modules comprises a box-shaped upper frame structure 13 attached to the independent frame structures FRS(m). This box-shaped upper frame structure comprises means for attaching one or more panels so as to protect the delta-type heat exchangers from side winds or to avoid recirculating air between the delta type heat exchangers and the fans.

[0131] In a preferred embodiment, an air-cooled condenser apparatus of the induced draft type is provided as shown in FIG. 2, FIG. 4 and FIG. 5A wherein, for each module, the series of fans FAN(k) is installed above the delta-type heat exchanger units of the module. In these embodiments, each condenser module ACCM(i) of the series of condenser modules comprises a box-shaped upper frame 13 comprising a fan deck 14 located at height H2 with respect to the floor level and wherein H2H1>2.5 m. This fan deck is configured to support the series of fans FAN(k) so as to induce, when in operation, an induced draft through the delta-type heat exchanger units of a condenser module. By keeping the difference H2H1>2.5 m, a plenum is created between the top duct and the fans. In practice, H2 is larger than 7 m.

[0132] In other embodiments, an air-cooled condenser apparatus of the forced draft type is provided as shown in FIG. 3 where, for each module, the series of fans FAN(k) is installed below the delta-type heat exchangers. In these embodiments, each independent frame structure of the series of independent frame structures FRS(m) comprises means for attaching one or more of the series of fans FAN(k). This means for attaching is for example a fan support 15 as shown in FIG. 3 that is attached to for example to the supporting legs 11 of the independent frame structure FRS(m). Typically, the fans of the series of fans FAN(k) are attached 0.5 m to 2 m below the level where the delta-type heat exchangers are positioned. In this way a plenum is created between the fans and the delta-type heat exchangers. Therefore, the frame structures FRS(m) used for a forced type of air-cooled condenser have a height that is 0.5 m to 2 m higher than the frame structures that are used for systems that use induced draft where the fans are on top of the delta-type heat exchangers. In practice, for these embodiments, the fans of the series of fans FAN(k) are positioned at a height H3 larger than 2 m above the floor level.

[0133] In preferred embodiments according to the invention, as illustrated in FIG. 11 and FIG. 12, the top duct 2 of each of the delta-type heat exchanger units of each module comprises a first top duct section 2a and a second top duct section 2b. This first top duct section 2a can also be named steam manifold and the second top duct section can also be named air take-off header. In these preferred embodiments, the first set 40 and the second set 41 of parallel tubes comprise primary tubes 50,51 and secondary tubes 52,53 and the primary tubes are connected to the first top duct section and the secondary tubes are connected to the second top duct section. In this way, the primary tubes connected to the first top duct section 2a are configured for operating in a parallel flow mode wherein the steam and the condensate flow in the same direction. The secondary tubes connected to the second top duct section 2b are configured for operating in a counter flow mode wherein the steam flows in the opposite direction of the flow of the condensate flow. The second top duct section 2b allows for evacuating non-condensable gases and/or non-condensed steam. In FIG. 11 and FIG. 12, the large black arrows shown on the first panel section formed by primary tubes 50 and the second panel section formed by secondary tubes 52 indicate, when in operation, the direction of the steam flow through the primary 50 and secondary tubes 52.

[0134] The first panel section formed by the primary tubes and the second panel section formed by the secondary tubes can either be adjacent panels as shown on FIG. 10, or the two panel sections can slightly be separated in space as illustrated in FIG. 11. The advantage of leaving some spacing between the first section and the second section of the panels is to allow for some expansion of the panel sections due to the temperature of the fluid in the tubes. This expansion is different in the first section of the panel and second section of the panel as the temperature of the fluid in the primary and secondary tubes is different.

[0135] In embodiments, as shown on FIG. 11, the first manifold section 2a has a tubular shape with an entrance opening 35 on one end to receive steam and a cover 36 on the other end of the first manifold section, and the second manifold section 2b comprises an exit opening 37 for evacuating non-condensable gases and/or non-condensed steam.

[0136] Delta-type heat exchanger units comprising condenser panels having primary and secondary tubes as discussed above are known in the art. When in operation, steam from the turbine enters the entrance opening 35 of the first top duct section 2a and then goes through the primary tubes where the steam is condensed. Non-condensable gases and/or remaining steam that is not condensed in the primary tubes enters via the steam/condensate manifolds in the secondary tubes. The remaining steam can be further condensed in the secondary tubes in a counter flow mode, discussed above. The non-condensable gases that arrive in the second section 2B of the top duct 2 are then evacuated through the exit opening 37, typically using a pump.

[0137] As known in the art, the first top duct section 2a and the second top duct section 2b have to be construed as two distinct manifolds, i.e. there is no direct fluid connection between the two sections. The only fluid connection between the two manifold sections is an indirect connection via the primary tubes, followed by the steam/condensate manifold and finally the secondary tubes. In embodiments, the diameter of the second top duct section 2b can be smaller than the diameter of the first top duct section 2a as illustrated on FIG. 12.

[0138] According to a second aspect of the invention, a method for manufacturing, transporting and assembling an air-cooled condenser apparatus is provided.

[0139] In a first step a) a plurality of delta-type heat exchanger units 1 are manufactured in a factory. Each delta-type heat exchanger unit 1 comprises a top duct 2, a first set and a second set of tubes and a first and second steam/condensate manifold. The first 5 and second 6 steam/condensate manifold have a length PL that is comprised in the range 8.0 m<PL<13.7 m and the tube length of the tubes is comprised in the range 1.5 m<TL<2.5 m. The opening angle between the first set and second set of tubes is within the range 4565.

[0140] Preferably, the top duct 2 also has a length between 8.0 m and 13.7 m. As discussed above, the top duct 2 can comprise a first section and a second section and the total length of the top duct is determined by the length of the first and second top duct section.

[0141] During this manufacturing step in the factory, an upper end of the first set of tubes is connected to the top duct 2 and a lower end of the first set of tubes is connected to a first steam/condensate manifold. And similar, an upper end of the second set of tubes is connected to the top duct and a lower end of the second set of tubes is connected to a second steam/condensate manifold. In this way, a fully assembled delta-type heat exchanger unit is obtained in the factory and can be further transported to a site of installation as one assembled unit.

[0142] In a step b), the plurality of manufactured delta-type heat exchanger units are transported to an installation site where the air-cooled condenser apparatus is to be operated. In a preferred embodiment, each delta-type heat exchanger unit is placed in a separate container, i.e. there is one container per delta-type heat exchanger unit. Advantageously, each delta-type heat exchanger unit rests with its first and second steam/condensate manifold on a floor level of the container or on a transportation support located on the floor level of the container. The transport support is for example a frame that is used to protect the delta-type heat exchangers during transport or the transport support is a protecting packaging around the first and second steam/condensate manifold or the transportation support can comprise wheels to facilitate placing the delta-type heat exchanger unit in the container.

[0143] In a final step c), the air cooled condenser apparatus is assembled at the installation site. This step comprises the sub-step of placing a support structure configured to support the plurality of delta-type heat exchanger units. In a second sub-step, one or more condenser modules are formed by performing for each module the steps of positioning two or more delta-type heat exchanger units on the support structure so as to form a row of delta-type heat exchanger units, and by installing one or more fans configured to generate an air flow through the delta-type heat exchanger units of the module.

[0144] In some embodiments, as illustrated in FIG. 9A and FIG. 9B, the step of manufacturing a plurality of delta-type heat exchanger units 1 in a factory comprises a sub-step of attaching a strengthening element 31 to the delta-type heat exchanger unit.

[0145] Those strengthening elements 31 can either be removed during the installation phase on the site of installation or alternatively, those strengthening elements can be remained in place.

[0146] In embodiments, as shown on FIG. 9A, the strengthening element 31 comprises a strengthening beam attached with one end to the first steam/condensate manifold and attached with a second end to the second steam/condensate manifold.

[0147] In some embodiments, the step of assembling the air cooled condenser apparatus at the installation site, comprises a step of removing the one or more strengthening beams 31. Alternatively, the one or more strengthening beams are not removed during the assembling at the installation site.

[0148] In other embodiments, as illustrated in FIG. 9B, the strengthening element 31 comprises a covering plate having a triangular shape. By attaching two of these plates to the sides of the delta-type heat-exchanger, the sides are covered. When in operation, those covering plates prohibit the air to escape through the sides of the delta-type heat exchanger and force the air to go through the condenser panels 3,4. In some embodiments, the strengthening elements 31 comprise both, one or more strengthening beams and two cover plates to cover the sides of the delta-type heat-exchanger.

[0149] According to a third aspect of the invention a process to engineer and manufacture an air-cooled condenser apparatus for condensing a steam flow from a turbine is provided.

[0150] In a first step a) a delta-type heat exchanger unit 1 (HEXU) is designed. Such a delta-type heat exchanger unit comprises, as shown on FIGS. 1A,1B,10,11 and 12, a top duct 2, a first condenser panel 3 comprising a first set of parallel tubes, a second condenser panel 4 comprising a second set of parallel tubes, a first steam/condensate manifold 5 and a second steam/condensate manifold 6. The HEXU is characterized in that the length TL of the tubes of both the first set and second set of parallel tubes is within the range: 1.5 m<TL<2.5 m and the length PL of both the first 5 and second 6 steam/condensate manifold is comprised in the range: 8.0 m<PL<13.7 m. The first and second condenser panel are positioned with respect to each other such that there is an opening angle between the first and the second condenser panel within the range: 4565 as shown on FIG. 1A.

[0151] Preferably, the delta-type heat exchanger unit is a self-supporting device. A self-supporting delta-type heat exchanger unit has to be construed as a HEXU that is designed to support its own weight, i.e. the steam/condensate manifolds 5,6 are designed to support the weight of the top duct and the weight of the first and second condenser panel. As a result, the self-supporting HEXU can be simply positioned with the first steam/condensate manifold 5 and second steam/condensate manifold 6 resting on for example a support frame or resting for example on the floor of a container.

[0152] In a second step b), a condenser module is designed by grouping a number UN of the delta-type heat exchanger units in rows next to each other. In some embodiments, as illustrated in FIG. 2 and FIG. 3, two heat exchanger units (UN=2) are grouped together to form a module while in alternative embodiments, as for example shown on FIG. 8, three heat exchanger units (UN=3) are grouped together.

[0153] The condenser module is further designed by defining a required number FN of air fans aligned along an axis parallel with the direction of the top ducts of the grouped delta-type heat exchangers. As there is one row of aligned fans for multiple rows of delta-type heat exchanger units, the number of required fans is kept to a minimum. In this way the power consumption is limited.

[0154] In a further step c), a first model of independent frame structure for supporting all delta-type heat exchanger units of one condenser module and/or designing a second model of independent frame structure for supporting all heat exchanger units of two condenser modules are designed. Alternatively, a third model of independent frame structure for supporting all heat exchanger units of three condenser modules is designed. In some embodiments, only the first model of frame structure is designed but in a preferred embodiment both the first and the second model of frame structures are designed as this increases the modularity. A model of a frame structure has to be construed as an open structure comprising supporting beams located at a height H1 with respect to a floor level and comprising legs attached to the supporting beams for holding the supporting beams at the height H1. The delta-type exchanger units can then be positioned on top of those supporting beams.

[0155] In step d) for a given steam flow from the power plant, a required number NMOD of condenser modules to condense the steam are determined.

[0156] In step e), a required number of first model NMODA and/or a required number of second model NMODB and/or a required number of third model NMODC of independent frame structures for supporting the required number NMOD of condenser modules are determined.

[0157] In step f), the delta-type heat exchanger units are assembled in a factory. The total number UTOT to be assembled is equal to UTOT=UNNMOD. The assembly in the factory comprises the sub-steps of attaching a first end of each tube of the first condenser panel to the top duct 2, attaching a second end of each tube of the first condenser panel to the first steam/condensate manifold 5, attaching a first end of each tube of the second condenser panel to the top duct 2, attaching a second end of each tube of the second condenser panel to the second steam/condensate manifold 6. Attaching the tubes to the top duct and the steam/condensate manifold has to be construed as performing a vacuum tight connection. Attaching the tubes to the top duct and the steam/condensate manifold comprises the performance of shop welding.

[0158] In step g), each of the assembled delta-type heat exchanger units 1 is placed in a container for transportation to an installation site.

[0159] In a final step h), the air cooled condenser apparatus is erected at the installation site. This comprises sub-steps of positioning the required number of first and/or second and/or third independent frame structures, positioning the delta-type condenser units 1 of each of the condenser modules on top of the first and/or second and/or third independent frame structures, and, for each condenser module, installing the required number FN of fans.