US20110308764A1

US20110308764A1 - Air-cooled condenser system and method for setting up such a condenser plant

Info

Publication number: US20110308764A1
Application number: US13/254,110
Authority: US
Inventors: Raimund Witte
Original assignee: GEA Energietchnik GmbH
Current assignee: GEA Energietchnik GmbH
Priority date: 2009-03-06
Filing date: 2010-02-12
Publication date: 2011-12-22
Also published as: WO2010099774A2; KR20110134374A; ZA201102589B; EP2404131A2; WO2010099774A3

Abstract

An air-cooled condenser system (1) comprises a platform (2) carrying heat exchanger elements (4), steam distribution lines (6), and fans (5). The platform (2) is arranged on pillars (3), which previously are introduced into the soil beneath the platform. The platform (2) is mounted close to the ground, wherein the intake chamber (21) required beneath the platform (2) is formed by removing soil beneath the platform (2). In this way, the platform (2) can be mounted at low height and with little effort.

Description

The invention relates, on one hand, to an air-cooled condenser system according to the features in the preamble of claim 1.
The other hand, the invention relates to a method for constructing an air-cooled condenser system according to the features in the preamble of claim 11.
A conventional air-cooled condenser system has several condensers in the shape of a roof located on a platform, wherein the condensers are supported by pillars and are supplied with steam, wherein fans supported on the platform are located underneath the condensers.
The condensers in such condenser systems are typically arranged at a greater height, leaving adequate unobstructed space underneath the condensers through which the fans can suction the necessary cooling air from the environment of the condenser system and distribute the cooling air across the condensers for condensing the steam streaming through the condensers. Due to the height of the condensers, the wind loads acting on the condenser system are comparatively high, so that the entire substructure of the condensers system must be designed with adequate stability. In addition, it must be taken into account that the assembly of the condenser system requires a significant number of large pieces of equipment, such as cranes and scaffolding. In addition, the installers must work at great heights.
It is the object of the invention—starting from this state-of-the-art—to provide an air-cooled condenser system and a method for constructing such condenser system, wherein particularly the installation complexity can be reduced. The susceptibility of the installed system to wind should also be reduced.
The solution relating to the device aspect of the object is recited in claim 1.
Accordingly, the pillars supporting the platform are anchored in the ground in an excavation formed in the soil underneath the platform. This has the significant advantage that, after the pillars are introduced/driven into the ground, the platform can be installed with the heat exchanger elements and the steam distribution lines as well as the lines discharging the condensate directly at the height of the ground surface, i.e., close to the ground. This significantly reduces the complexity and the assembly of the system, especially relating to cranes and scaffolding. The work is made much easier for the installers because they can now perform their work at a low height.
Only after the condenser system is in most parts or completely assembled, an excavation is produced underneath the platform. The size of the excavation or the slope angle of the preferably inclined edges is hereby dimensioned so that a sufficiently large unobstructed space exists underneath the platform which allows the cooling air suctioned from the environment by the fans to flow through. The slope angle of the edges is approximately between 15° and 45°. A smaller slope angle below 15° would make the horizontal extent of the excavation quite large, requiring a large amount of material to be excavated. The space required for the system and also the wind loads acting on the condenser system increase with decreasing slope angles. The wind loads decrease with a greater slope angle, so that the slope angle should remain below a minimum slope angle.
Within the context of the invention, the slope angle of the excavation may not be identical on all sides of the excavation, but may be different, for example commensurate with the prevailing local wind direction.
A so-called stationary operation is desired in practical applications, i.e., in an operation where there is no wind. In still air, it is ensured that all fans suction in cooling air and supply the cooling air to the heat exchanger elements almost uniformly. Because a situation where there is no wind is rare, the condensers receive cooling air unevenly, which reduces the condenser efficiency and hence also the efficiency of the power plant. Because the condenser system with the heat exchanger elements is now arranged directly at the ground level, the wind speeds underneath the platform are comparatively low compared to conventionally supported condenser systems even at higher wind speeds. More uniform and hence more advantageous flow conditions are therefore attained even at higher wind speeds.
Advantageously, the wind loads acting on the condenser system in the horizontal direction can be significantly reduced, because the wind speeds at ground level are lower than at a height of, for example, 50 m. In particular, the wind walls along the periphery of the heat exchanger elements can be of lighter weight and have a smaller height.
The edges of the excavation should only start in regions near the platform, so that the air can flow to the side of the intake chamber without obstruction. The distance between the surface of the floor of the excavation and the bottom edge of the platform can then be identical across the entire horizontal extent.
In particular, an intake chamber with sufficient height underneath the platform is attained when a horizontal floor surface of the intake chamber bounded by the sloped edges is greater than the horizontal base surface of the platform.
For supplying the condensers on the platform with cooling air with the greatest possible uniformity, a mound with a sloped embankment may be provided on the floor of the excavation. This mound intentionally deflects cooling air from the entrance regions of the excavation on the side of the condenser system into the region underneath the heat exchanger elements, and simultaneously operates as a wind breaker.
The mound has a particularly high efficiency if its height is selected to be between 30% and 70% of the distance between the surface of the floor of the excavation and the bottom edge of the platform. In particular, the height of the mount is about 50% of that distance.
The susceptibility of the condenser system to wind can be further reduced by arranging on the edge of the excavation a wall positioned on the ground. The crest of this wall should be higher than the height of the platform. In particular, the crest should be located in a horizontal plane intersecting with the top edges of the heat exchanger elements. This additionally creates a noise abatement wall by blocking sound propagating from the condenser system.
Within the context of the invention, the wall may also be deposited with different heights commensurate with the prevailing wind direction, so that the crest must not necessarily have the same height at all places. The wall may also be constructed only on one side or two sides of the condenser system and must not necessarily surround the entire condenser system, since the lengths of the lines from a turbine house, where the water vapor to be condensed is produced, to the condenser system should be kept as short as possible. A wall placed on the side of the turbine house would increase the lengths of the lines. For this reason, a wall is preferably arranged only on three sides.
As another advantage, the wall may be constructed from the soil removed during excavation, so that additional building material need not be delivered.
The platform may even be installed at a relatively low height above ground level, if there exists already a significant distance from the ground level to the bottom edge of the platform. This distance is increased by removing soil below the platform for forming the intake chamber. The excavated soil is used for the wall. In this way, the trough-shaped excavated area with a low depth can be formed, because the wall represents an additional wind barrier which reduces the susceptibility of the condenser system to wind.
The solution of the part of the invention relating to the method of the underlying object is recited in the features of claim 11.
In the method of the invention, pillars are first introduced into the ground, in particular driven into the ground or cast in the ground. The platform is then installed on these pillars, with fans, heat exchanger elements and steam distribution lines attached to the platform, mentioning only the largest assemblies. Of course, additional pipe systems and components may be arranged on such platform.
Importantly, with the method of the invention, the soil underneath the platform is removed to a greater extent following the installation of the platform so as to form an excavated area which then operates as an intake chamber for inflowing air. Depending on the distance of the platform from the ground during the installation phase, the intake chamber may be formed or enlarged by excavating soil. Preferably, the platform is arranged during the installation as close as possible to the ground. In other words, the pillars are introduced into the ground to a great depth. In this case, the condenser system can quasi be installed on the ground. However, the platform may also be installed at the height of, for example, 5 m or 10 m above the ground, wherein this night is subsequently at least doubled by removing soil so as to produce a sufficiently large intake chamber.
In the context of the invention, excavation is removal of the soil to an extent so as to significantly affect the flow conditions. In particular, excavation should include soil removal of at least 1 m, preferably several meters, and over a larger area which represents at least 50% of the area underneath the platform.
To ensure a uniform flow to the fans from below, a mound with a sloped embankment can be formed on the floor of the excavation. In this context, forming is meant to indicate that the mound can be deposited or can remain while only the surrounding soil is excavated. Of course, the second approach is much more advantageous because less soil needs to be moved.
Because the method of the invention has the aim of protecting the condenser system from nonuniformly inflowing winds, the excavated soil can be used directly for depositing a wall on the side of the excavation. Depending on the size of the excavation and the desired height of the wall, additional material may of course be used. With a wall, the condenser system may then also advantageously be positioned at a somewhat greater height if it can be assumed that the crest of the wall is located approximately at the height of the platform, preferably at the height of the top edge of the condenser systems. In this case, the pillars need not be introduced too deeply into the ground. Although the platform is then installed in a somewhat raised position, this is still not as difficult as an installation at a height of, for example, 50 m.
It will be understood that within the context of the invention a wall may be deposited even if the condenser system is installed quasi at ground level. In this situation, the crest of the wall projects over the top edge of the condenser system, so that the condenser system is arranged in the trough-shape excavation and fully protected from the wind.
To enable a uniform flow to the fans, the edges of the excavation are constructed with a slope angle of 15° to 45°.

The invention will now be described in more detail with reference to exemplary embodiments illustrated in the drawings, which show in:

FIG. 1 in a schematic vertical cross-section, an air-cooled condenser system, and

FIG. 2 also in a schematic vertical cross-section, an air-cooled condenser system according to a further embodiment.

FIG. 1 illustrates an air-cooled condenser system designated with 1. This condenser system 1 includes a horizontal platform 2 which is supported by several vertical pillars. Heat exchanger elements 4 supplied with steam, in form of condensers and dephlegmators, are arranged above the platform 2 in a roof structure. Fans 5 supported on the platform are arranged below the heat exchanger elements 4. Steam distribution lines 6 extend on the ridge side of the heat exchanger elements 4. The required lines for feeding steam to the condenser system 1 and for discharging the condensate from the heat exchanger elements 4 are not illustrated so as not to obscure the clarity of the drawing. Wind walls 7 are provided along the peripheral sides of the heat exchanger elements 4 and/or the platform 2.
When the condenser system is constructed, pillars 3 are first introduced with sufficient depth from the surface 8 of the ground 9 into the ground 9. After the platform 2 with the heat exchanger elements 4 and with all steam and condensation lines, including the lateral wind walls 7, are installed on the pillars 3, wherein the condenser system 1 is located directly proximate to the surface 8 of the ground 9, a trough-shaped excavation 10 is excavated underneath the platform 2. The excavation 10 has lateral edges 11 which in the exemplary embodiment extend at an angle α of 25° with respect to the ground surface 8, i.e., to the horizontal. The edges 11 are arranged in regions next to the platform 2.
A mound 12 with sloped embankments 13 is provided on the floor 14 of the excavation 10 underneath the platform 2. This mound 12 can be formed from the excavated material of the excavation 10. The height H of the mound 12 corresponds approximately to half the distance A between the surface 15 of the floor 14 of the trough 10 and the bottom edge 16 of the platform 2. The distance A also defines the height of the intake chamber 21. The intake chamber 21 is the region below the platform, via which air can flow to the fans 5.
The arrows K indicate the cooling air suctioned by the fans 5 from the environment U of the condenser system 1, while the arrows A indicate the outflowing air heated on the heat exchanger elements 4 during heat exchange.
In the embodiment illustrated in FIG. 2, which is constructed identically to the condenser system 1 of FIG. 1, a wall 17 is constructed on the ground 9 at the edge of the excavation 10. The crest 18 of the wall 17 extends approximately in a horizontal plane HE, which also intersects the top edges 19 of the steam distribution lines 6 of the condensers 4. The edges 11 transition smoothly into the sloped edges 20 of the wall 17, i.e., the embankment 20 has the same angle as the edges 11 of the excavation 10.
However, it can be seen that the platform 2 of the condenser system 1 is arranged at a greater height than the platform 2 in FIG. 1. The depth T of the excavation 10 may then be smaller, thus reducing the amount of material that needs to be excavated when building the excavation 10.
In all other aspects, the embodiment of FIG. 2 corresponds to that of FIG. 1.

LIST OF REFERENCES SYMBOLS

1 Condenser system
2 Platform of 1
3 Pillars for 2
4 Heat exchanger elements of 1
5 Fans for 4
6 Steam distribution lines
7 Wind walls
8 Surface of 9
9 Soil, ground
10 Excavation
11 Edges
12 Mound
13 Embankments of 12
14 Floor of 10
15 Surface of 14
16 Bottom edge of 2
17 Wall
18 Crest of 17
19 Top edges of 6
20 Embankment of 17
21 Intake chamber
A Distance between 15 and 16
A Heated exhaust air
H Height of 12
HE Horizontal plane
T Depth of 10
Environment of 1
K Inflowing cooling air
α Angle between 8 and 11

Claims

1-16. (canceled)

17. An air-cooled condenser system, comprising:

a platform having heat exchanger elements, steam distribution lines and fans, pillars supporting the platform, and

an intake chamber formed underneath the platform at least partially by an excavation in the ground.

18. The condenser system of claim 17, wherein the excavation has sloped edges.

19. The condenser system of claim 18, wherein the sloped edges have a slope angle of approximately 15° to approximately 45°.

20. The condenser system of claim 18, wherein the sloped edges are arranged in regions next to the platform.

21. The condenser system of claim 17, wherein the intake chamber comprises a horizontal floor area bounded by the sloped edges and wherein the horizontal floor area is greater than the horizontal base area of the platform.

22. The condenser system of claim 17, wherein a mound with sloped embankments is arranged on a floor of the excavation underneath the platform.

23. The condenser system of claim 22, wherein a height of the mound is between 30% and 70% of a distance between a surface of the floor of the excavation and a bottom edge of the platform.

24. The condenser system of claim 17, further comprising a wall arranged at an edge of the excavation, with a crest of the wall projecting above a height of the platform above ground level.

25. The condenser system of claim 24, wherein the crest is located in a horizontal plane which intersects top edge of the heat exchanger elements.

26. The condenser system of claim 24, wherein the wall is formed from soil excavated from the excavation.

27. A method for constructing an air-cooled condenser system having a platform supported on pillars, with fans, heat exchanger elements and steam distribution lines installed on the platform, the method comprising the steps of:

introducing the pillars into the ground,

mounting the platform on the pillars, and

forming an excavation underneath the platform so as to form or to enlarge an intake chamber underneath the platform.

28. The method of claim 27, wherein the platform is mounted on the pillars at ground level and the intake chamber is formed in its entirety by removing soil from underneath the platform.

29. The method of claim 27, wherein the platform is mounted on the pillars at a height above ground level, wherein the height is smaller than a vertical height of the intake chamber after completion, wherein the vertical height of the intake chamber is increased by removing soil from underneath the platform.

30. The method of claim 27, further comprising the step of forming a mound with a sloped embankment on a floor of the excavation underneath the platform.

31. The method of claim 27, further comprising the step of constructing a wall at an edge of the excavation.

32. The method of claim 31, wherein the wall is constructed from soil removed from the excavation.