AIR CONDENSER

Abstract

An air condenser with upward oriented tube bundles for condensing steam, wherein the tube bundles form sidewalls of a cell in form of a circumferentially closed, vertically extending polygon, wherein a fan is arranged above the polygon. Two of the circumferential sidewalls of the cell are formed by tube bundles, wherein these sidewalls enclose an angle smaller than 90° and wherein the at least one further side wall is impermeable to air.

Description

The invention relates to an air condenser with the features set forth in the preamble of patent claim 1.

Air-cooled condensers serve for the direct condensation of exhaust steams, in particular of turbine steam. They can be regarded as a special application of air-cooled heat exchangers, which serve for the cooling of fluids in various processes of the chemical, petrochemical and power generating industry by means of ambient air. The used heat exchangers essentially include heat exchanger tubes, which because of the poor thermal conductivity of air are provided with fins on the outside to facilitate heat transfer. Multiple of these tubes provided with fins, are combined to so-called tube bundles which, in planar construction, are exposed to a cooling air stream. The cooling medium air is advanced through the heat exchanger bundles by means of ventilators in an aspirating or pushing arrangement.

Oftentimes, the heat exchanger bundles are arranged roof-shaped above the cooling air ventilators. In order to guarantee air supply at the lowest possible pressure losses, the heat exchanger bundles which are arranged roof-shaped, and the ventilators which are arranged underneath, are together supported by a support structure. The turbine exhaust steam to be condensed is conducted through an exhaust steam duct and the adjoining upper steam distributor ducts into the fin tubes. The constructional effort for the support construction is not insignificant.

Beside the roof-shaped construction, the state of the art also includes air condensers in which tube bundles extend vertically and form a closed sheath of a polygon (EP 1 710 524 A1). Such a polygon requires less space, because an elaborate support structure is not needed. A disadvantage is however, that when doubling of the cooling capacity is desired, the for example hexagonally configured cells cannot be mounted in a space saving manner directly adjacent to one another, because in this case the two abutting sidewalls would cover one another and thus prevent aspiration of air through the heat exchangers that are arranged in these sidewalls. In a serial arrangement with for example three hexagonal cells, the opposing heat exchanger elements of the middle cell would be covered and of course also those of the neighboring cells. Even more unfavorable is a honeycombed, i.e. staggered, arrangement of three hexagonal heat exchanger elements, because in this case even more side surfaces would block one another. Even in the case of two adjacently extending rows of hexagonal cells, which only contact each other at their tips, only relatively small spaces, which lack a sufficient cross sectional surface for adequate air supply, remain between the cells. In order to enlarge the spaces, the distance between mutually parallel extending rows would have to be increased, which in turn requires more installation surface.

Based on the foregoing, the invention is based on the object to provide an air condenser which in modular construction can also be extended for higher cooling capacities, i.e. is easily scalable, which however, does not require an elaborate steel construction for supporting the tube bundles.

This object is solved by an air condenser with the features of patent claim 1.

The sub claims relate to advantageous refinements of the invention.

First, the air condenser according to the invention is characterized by upwards oriented tube bundles for condensing steam. The tube bundles form sidewalls of a cell in the form of a circumferentially closed, upwards, i.e. vertically extending polygon, wherein the polygon itself lies in a horizontal plane. This polygon, which is configured with tube bundles as sidewalls, is provided with a fan which is arranged above the polygon in a manner so as to aspirate cooling air. In the air condenser according to the invention, two of the circumferential sidewalls of the cell are formed by tube bundles, while the at least one further sidewall is impermeable to air. The sidewalls formed by the tube bundles form an angle of 90° with one another.

This construction purposely provides for not using more than two sidewalls for the heat exchange, while the remaining sidewalls are closed, in order to seal the space enclosed by the cell so that cooling air is aspirated by the fan exclusively through the tube bundles. This allows combining multiple cells having this configuration, in a space-saving manner without blocking one another or delimiting a too narrow air intake space outside the cells.

The basic shape of such a cell is the triangle or a straight cylindrical hollow space with a triangular base area, respectively. Generally, it is assumed that such an air condenser is installed on a solid floor surface, so that an arrangement of the air condenser close to the ground obviates an elaborate support structure, as it is required for air condensers which are arranged roof-shaped.

The sidewalls formed by the tube bundles can well be longer than the at least one sidewall, which interconnects the spaced apart ends of the tube bundles. This results in a non-isosceles triangle. When multiple air-impermeable sidewalls are provided, these extend either between the confronting ends of the tube bundles or between the ends of the tube bundles which face away from each other.

A further basic shape is represented by deltoid cells. A deltoid, which is also referred to as kite quadrilateral, is a flat quadrilateral with two pairs of adjacent sides of equal lengths. Within the context of the invention, this means the convex shape of the deltoid. Applied to the invention this means that the tube bundles are one of two pairs of sidewalls of equal lengths, wherein the other pair of mutually adjacent sidewalls is formed by the air-impermeable sidewalls.

The strict deltoid shape can be interrupted by arranging a very narrow sidewall between the mutually adjacent ends of the tube bundles. Narrow in this context means that the sidewall extends over a much smaller circumferential region of the cell than one of the neighboring tube bundles, thus creating a pentagon.

Similar as in a triangle-shaped or deltoid-shaped cell, the basic shape of the pentagonal cell is configured mirror-symmetrical with regard to a vertical plane of symmetry intersecting the cell, however not rotationally symmetric. This means that due to the different lengths sidewalls, the basic shape of the cell cannot be projected onto itself when rotated by an angle different from 360°. This also has the consequence that the angle enclosed by the tube bundles is smaller than the angle enclosed by the air-impermeable sides. This means the inner angle of the cell enclosed by the directly adjacent tube bundles. Enclosed angle however, also means the angle which results when a narrow air-impermeable sidewall is further arranged between the mutually adjacent ends of the tube bundles.

As an alternative to deltoid-shaped cells it is also conceivable, that the basic shape of the cell is trapeze-shaped. This means that the tube bundles which form an angle smaller than 90° with each other, form legs of the trapeze, while the further air-impermeable sidewalls form the mutually parallel base sides of the trapeze. Naturally, in this geometry the longer base side is the one which extends between the ends of the mutually distally positioned tube bundles. The other base side, which extends parallel to the first base side, is significantly shorter corresponding to the angular position of the tube bundles. The trapeze-shaped cell is a special form of the triangle-shaped cell.

In a further embodiment of a triangle-shaped or also trapeze-shaped cell, the ends of the spaced apart positioned tube bundles, are connected to one another by sidewalls which are arranged U-shaped. U-shaped in this context means that the sidewall does not extend in a straight line from the one tube bundle to the other tube bundle, but rather has an arched course, however, in particular is angled two-fold, resulting in a U-shaped course when viewing the cell from the top. In this case, the cell has quasi a triangle- or trapeze-shaped part, whose sidewalls are formed by the tube bundles, and a rectangle-shaped part which is formed by the air-impermeable sidewalls. Of course, no closed intermediate wall is present between the triangle-shaped and the rectangle-shaped region.

Within the context of the invention it is well possible to provide sidewalls which are angled once or multiple times instead of the U-shaped form, wherein a single angled portion corresponds to a V-shape and thus a deltoid base structure, and multiple angled portions in the extreme case lead to a semi-circle or arched course.

In the context of the invention it is possible to arrange multiple cells configured in this manner atop one another, thereby delimiting a straight cylinder space above which a fan can be placed. Because the fans are limited in their capacity to the maximum inner circle of the cylinder space, additional fans may be required. Additional fans can be arranged in the sidewalls previously referred to as air-impermeable, which means in a right angle relative to the head-side fan at the upper end of the cylinder space.

As an alternative to the stacked arrangement it is regarded particularly advantageous, when multiple cells are combined to form an arrangement in which two rows are arranged horizontally adjacent to one another and extend parallel to one another, and in which the air-impermeable sidewalls are arranged so as to face one another and the sidewalls which are formed by the tube bundles form the outside of the rows. Here, the particular advantages of the invention that the tube bundles do not block one another come to bear. The triangle cells, trapeze cells and deltoid cells can be arranged in one row without any impediment to airflow as well as in two rows, also referred to as in blocks, with the cells again not interfering with each other with regard to the air intake space.

This possibility to position the individual cells next to one another in a space-saving manner results in the advantage to install the scalable air condensers according to the invention also in the case of higher cooling capacity without loss of performance. In a standardized construction, the individual cells require no modification. In particular, in contrast to the state of the art, no heat exchanger surfaces are lost in the arrangement in blocks.

Trapeze-shaped cells allow neighboring, confronting sidewalls to be in such close proximity to one another that one of the rear-side sidewalls can be omitted. In any case, however, one sidewall is retained, so that in a direct back-to-back arrangement no cooling air is aspirated by the fans of one of the trapeze-shaped cells through the heat exchangers of the other trapeze-shaped cell. Instead of being combined into a hexagonal cell, two trapeze-shaped cells thus remain trapeze-shaped in their layout.

When rows of cells which extending parallel to one another are provided, the steam manifold, which supplies the steam which is to be condensed, is arranged between the rows, so that junctions which branch off from both sides of the steam manifold can be guided to the top sides of the tube bundles. The steam enters into the tube bundles from above. The condensate which is generated in the tube bundles, drains downwards and is discharged via condensate collecting mains.

The supporting structure of the tube bundles and the sidewalls is configured so that the steam manifold is supported as well. This applies to triangle-shaped and trapeze-shaped cells, as well as to the cells with a deltoid-shaped cross section, which substantially form a stable support with their sidewalls which abut one another at their edges in back-to-back arrangement, exactly at the site where the heavy steam manifold extends. This allows for significant savings with regard to the support structure. Overall, less tonnage has to be moved, which allows realizing the installation of the entire air condenser in a more cost efficient-manner. Depending on the dimensioning, it may be necessary to support the main exhaust steam duct by a separate steel structure or concrete supports.

In any way, the new construction is especially economical compared to previous constructions. Especially compared to the roof-type construction, significant savings can be achieved in air-cooled condensers with regard to material costs and installation costs. The cost saving is primarily due to the fact that the heat exchanger bundles are mounted on a steel construction or concrete support, which are horizontally arranged on the ground. The ventilation system which includes the fan, engine and the raceway which surrounds the fan, can be configured in a similar manner as in wet cooling towers which are configured in cell-type construction, wherein an inspection and maintenance of the ventilation system can occur through a bridge which hangs underneath the fan and is made in particular of glass fiber-reinforced plastics.

Individual cells are accessed via a door arranged in the tip. A tip means for example the region between two adjacent ends of the condenser. Because a door is preferably located at this position, the adjacent ends of the air condensers do not directly border one another, but are connected to one another via a narrow sidewall, which is not significantly wider than the door.

It is further regarded as particularly economical, when the main supply of cells which are connected in series and arranged parallel to one another, takes place by a steam manifold which extends between the cells. The individual cells are each supplied via two respective ducts with one Y-branch duct and two junctions per cell, wherein each of these junctions leads to one respective tube bundle.

Moreover, savings also result in the region of the steam exhaust line. Steam exhaust duct means the duct between a turbine and a steam manifold. In a roof-type construction, the steam manifolds are arranged above the heat exchanger. Because of the small height in triangle cells, trapeze cells, kite cells or also in cells stacked upon one another, the steam exhaust duct does no longer have to be led to such a height as it is required in heat exchangers which are arranged roof-shaped. This results in a further reduction of material costs with regard to the steam exhaust duct.

As a result of the substantial reduction of material costs, installation costs are also significantly reduced, because less material has to be moved. A decreased construction height also means that smaller cranes can be used, that scaffolds and safety devices are not needed or can be reduced, and that installation can take place with means used in residential construction. Moreover, a parallel mounting is possible, allowing to shorten construction time.

In the following, the invention is explained in more detail by way of an exemplary embodiment shown in the drawings. It is shown in:

FIG. 1 a schematic three dimensional representation of an air condenser with a trapeze shaped cross section;

FIG. 2 a schematic three dimensional representation of an air condenser with a triangle shaped cross section;

FIG. 3 a plan view onto a deltoid shaped air condenser;

FIGS. 4 to 8 each a plan view on air condensers with different cross sections;

FIG. 9 a plan view on air condensers arranged in series;

FIG. 10 a plan view on deltoid shaped air condensers arranged in series;

FIG. 11 a plan view on a dual-row, block arrangement of trapeze shaped air condensers;

FIG. 12 a plan view on two rows of adjacently arranged deltoid shaped air condensers;

FIG. 13 a possible arrangement of multiple rows of trapeze shaped air condensers;

FIG. 14 a simplified perspective representation of air condensers stacked atop one another;

FIG. 15 a further schematic representation of air condensers arranged atop one another and stacked with associated steam distribution line, and

FIG. 16 a plan view on the supporting structure of deltoid shaped air condensers arranged in blocks.

FIG. 1 shows an air condenser 1 in a highly simplified and purely schematic representation which in cross section has a trapeze-shaped base area. Multiple of these air condensers 1 can be arranged adjacent to one another and as a result form a larger unit, which is then also referred to as air condenser. In this case, the individual unit shown in FIG. 1 is referred to as cell 2.

The shown cell 2 has vertically extending sidewalls. The sidewall 3 facing the viewer or the sidewall 4 positioned left in the image plane is formed by the not further shown tube bundles. The rearward sidewall 5, like the face-side sidewall 6, is closed. From the inside of cell 2, air can be exhausted upwards by aspiration through a fan 7, of which only the fan opening is shown. This causes cold ambient air to flow through the tube bundles or the sidewalls 3, 4, respectively, into the inside of cell 2. Steam which is conducted into the tube bundles of the sidewalls 3, 4 from above, condenses and can be conducted away via a not further shown condensate collecting main underneath the tube bundles. With the exception of the fan opening, the top side 8 of the cell 2 is closed, so that air can be aspirated exclusively through the tube bundles.

In the following, the reference signs introduced in FIG. 1 are retained for all further cell types.

The embodiment of FIG. 2 differs from the one of FIG. 1 merely in that the front sidewall 6 is not present. The basic shape of cell 2 is thus triangular. Correspondingly, the internal space of cell 2 is wedge-shaped.

FIG. 3 provides for a modification of the triangular- or trapeze-shaped cells 2, as they are shown in FIGS. 1 and 2. From this plan view it can be seen that it is a deltoid-shaped cell. The deltoid-shaped cell 2, like the triangle- or trapeze-shaped cell 2, again has two front sidewalls 3, 4 in which the tube bundles are arranged. Located in the tip between the front sidewalls 3, 4 is a narrow sidewall 6, as in the trapeze-shaped configuration of FIG. 1. Relevant is the difference on the rear side of cell 2. Instead of a single sidewall, three closed sidewalls 5, 9, 10 are now provided. The sidewalls 5, 9 of the deltoid-shaped cell 2 are closed and form a greater enclosed angle with one another than the sidewalls 3, 4 of the tube bundles. The closed sidewalls 5, 9, however, do not abut each other pointedly, but rather are connected to one another via a further sidewall 10, which extends parallel to the front sidewall 6 between the tube bundles. In the sidewalls 6, 10 in the tips for example doors can be arranged for maintenance work.

A significant difference compared to the embodiments of FIGS. 1 and 2 is, that the fan opening in this type of construction is shifted further backwards towards the closed sidewalls 5, 9 and lies only partially between the front sidewalls 3, 4 or the tube bundles, respectively. This allows realizing greater fan diameters with regard to the total surface of the top side 8. On the other hand, smaller cells 2 can be used with regard to the base area at constant fan diameters. In this embodiment, the center M of the fan 7 lies on a straight line, which extends between the rear ends 11, 12 of the sidewalls 3, 4 or the tube bundles, respectively, which rear ends face away from each other.

FIGS. 4 to 8 show different variants of possible cross sectional shapes of the individual cells. Common to all constructions is that the front sidewalls 3, 4 i.e. the tube bundles, form an angle W with one another, which is smaller than 90°. This also applies when the sidewalls 3, 4 are not directly adjacent to one another as in the triangular cell according to FIG. 4, but are connected to one another via a very narrow face-side sidewall 6, as in the variants of FIGS. 5, 7 and 8.

While the embodiments of the FIGS. 4 and 5 essentially correspond to the ones of FIGS. 2 and 1, the variant of FIG. 6 and the one of FIG. 3 differ in that the sidewalls 6, 10 in the tips are not present, thus resulting in an exact deltoid or kite quadrilateral. Moreover, in these variants, in contrast to the embodiment of FIG. 3, the center M of the fan 7 does not lie exactly on the connecting line between the rear ends 11, 12 of the sidewalls 3, 4, but is shifted somewhat in the direction of the sidewalls 3, 4. The fan opening thus lies to a larger degree between the tube bundles. A small portion lies outside of the tube bundles.

The variant of FIG. 7, in contrast to the one of FIG. 3, provides for only one front sidewall 6, however no rear sidewall 10. At this position, the sidewalls 5, 9 abut each other pointedly in an angle W1. However, the angle W1 is still greater than the angle W between the front sidewalls 3, 4 in which the tube bundles are arranged.

The embodiment of FIG. 8 is a combination between a trapeze-shaped and a rectangle-shaped region. As in the embodiments of FIGS. 1 to 7, the front region with the sidewalls 3, 4 is formed by tube bundles, which in turn are interconnected via a narrow sidewall 6. Extending rearwards, i.e. adjoining the rear ends 11, 12 of the tube bundles, is a sidewall 5 which is substantially configured U-shaped. The rearward sidewall 5 extends parallel to the front sidewall 6 and has been shifted further towards the back. The resulting free space between the sidewall 5 and the rear ends 11, 12 of the tube bundles has been closed via shorter sidewall sections which are perpendicular to the rearward sidewall 5, resulting in the U-shape. Accordingly, the deltoid-shaped cell shown in FIGS. 6 and 7 can be referred to as V-form.

All shown constructions have in common to be configured mirror symmetrical with regard to the drawn in axis of symmetry S, however, because of the different angles W, W1, cannot be projected onto themselves by rotation about a vertical axis, i.e. they are not configured rotationally symmetric.

FIGS. 9 to 12 show different possibilities of arranging multiple cells to a greater air condenser 1.

In FIG. 9, the individual cells 2 are configured trapeze-shaped. The bolder lines symbolize tube bundles 13, 14. The thin lines represent closed sidewalls 5, 6. FIG. 9 shows, that multiple of the shown cells 2 can be arranged in series, without the surfaces of the heat exchanger being covered.

The same applies to the deltoid-shaped cells 2, as they are shown in FIG. 10. The comparison between FIGS. 9 and 10 again makes clear how the fan 7 on the deltoid-shaped cells is shifted to the rearward region, which is closed by air-impermeable sidewalls 5, 9. In contrast to the embodiment of FIG. 9, this allows the cells 2 to move slightly closer together, while the heat exchanger surface remains the same.

FIGS. 11 and 12 show possible block set-ups of the air condensers 1. FIG. 11 uses the cell type shown in FIG. 9. The cells 2 are arranged rearwards and at first sight form hexagons. However, it is a serial arrangement of purely trapeze-shaped cells 2, wherein the trapeze-shaped cells 2 are closed by their rearward sidewalls 5. Air, which is aspirated via fans 7 of the upper row 15, can thus be aspirated only via heat exchangers of the upper row 15, but not via the cells 2 of the lower row 16.

The same applies to the variant of FIG. 12. There, it can be recognized that the deltoid-shaped cells of FIG. 10 are arranged in a block set-up. As a result of the more expansive rearward sidewalls 5, 9 of the cells 2, the rows 15, 16 are overall wider. However, in return more installation space is available between the fans 7, which installation space can be used for guiding a steam manifold between the fans 7.

FIG. 13 shows a possible arrangement of multiple rows 15, 16 of trapeze-shaped cells 2. This fanned-out air condenser 1 can be fed by a central exhaust steam duct. The individual cells 2 do not interfere with one another during air aspiration. Theoretically, any desired increase in cooling capacity is possible by extending the rows.

FIG. 14 shows a variant in which two cells 2, 17 were placed in stacked arrangement atop one another. The upper cell 2 corresponds to the construction of FIG. 1 with fan 7 positioned on top. The lower cell 17 has no fan on its top side, but one in the rearward sidewall 5. The fan 7 of the lower cell 17 thus is perpendicular to the fan 7 of the upper cell 2.

FIG. 15 shows a further variant of stacked cells 2, wherein for the four cells which are stacked atop one another, overall four fans 7 are provided, which are arranged in series adjacent to one another. Only the respective outer fans 7 protrude into the pointed, trapeze-shaped region of the cells 2. The intermediate fans 7 lie outside of the lower cells 17, which have an air-impermeable rear side. The air flows through the not further shown heat exchanger of the lower cells 17 into the space underneath the middle fan 7 and is then discharged upwards. A steam manifold 18 is provided to conduct steam to the cells 2, 17 which are stacked atop one another. The steam manifold 18 is located at about half the height of the upper cell 2, wherein respective junctions 19 lead from the steam manifold to the upper edges of the not further shown tube bundles of the cells 2, 17.

Finally, FIG. 16 shows a plan view on the supporting steel structure of an air condenser 1, similar to the construction in FIG. 12. The individual cells 2 are supported by a support structure, which in this case is deltoid-shaped corresponding to the base area of the cell. In this exemplary embodiment it can be recognized that the steam manifold 18, which is marked in a dashed line, can be passed exactly between the rearward regions of the individual cells 2. The steam manifold 18 is located above the top sides of the cells 2, i.e. also above the fan 7. Transverse to the respective tube bundles, a junction 19 branches off from the steam manifold 18, which is shown as an example for two cells 2 in the lower row 16. The junction 19 can also be referred to as Y-branch duct, i.e. as duct which bifurcates again. Each junction 20, 21 leading from the bifurcation conducts steam to the top sides of the shown tube bundles 13, 14. In this case, steam is conducted through the common junction 19 to the tube bundles 13, 14 of mutually adjacent cells. Of course, it is also conceivable to provide a respective junction for each cell 2, wherein the junction 19 in this case would have to be led around the fan 7. However, the shortest duct paths result when the junction 19 is passed between two adjacent cells 2.

REFERENCE SIGNS

• 1 Air condenser
• 2 Cell
• 3 Sidewall
• 4 Sidewall
• 5 Sidewall
• 6 Sidewall
• 7 Fan
• 8 Sidewall
• 9 Sidewall
• 10 Sidewall
• 11 End
• 12 End
• 13 Tube bundle
• 14 Tube bundle
• 15 Row
• 16 Row
• 17 Cell
• 18 Steam manifold
• 19 Junction
• 20 Junction
• 21 Junction
• M Center
• S Axis of symmetry
• W Angle
• W1 Angle

Claims

1.-11. (canceled)

12. An air condenser comprising:

a plurality of cells arranged to establish two horizontal rows in parallel side-by-side relationship, each said cell configured as a circumferentially closed, vertically extending polygon defined by sidewalls, wherein two of the sidewalls enclose an angle of less than 90° and are formed by upward oriented tube bundles for condensing steam and thereby define outer sides of the rows, and wherein further sidewalls are configured to be impermeable to air and face one another; and

a fan arranged above the polygon.

13. The air condenser of claim 12, wherein each of the cells is mirror symmetrical but not rotationally symmetric with regard to a vertical plane of symmetry which intersects the cells.

14. The air condenser of claim 12, wherein the two sidewalls formed by the tube bundles have a same length, and the further sidewalls have a same length, said cells being configured deltoid-shaped and defined by two pairs of said sidewalls, wherein one of the two pairs is formed by the two sidewalls formed by the tube bundles and the other one of the two pairs is formed by the further sidewalls.

15. The air condenser of claim 12, wherein the tube bundles have confronting ends, with one of the further sidewalls being arranged between the ends and extending over a circumferential region which is smaller than one of the tube bundles.

16. The air condenser of claim 12, wherein the angle defined between the two sidewalls formed by the tube bundles is smaller than an angle defined between the further sidewalls.

17. The air condenser of claim 12, wherein each cell has a cross section in the shape of a trapeze, said tube bundles having legs extending at an angle of less than 90° to one another, said further sidewalls forming parallel base sides of the trapeze.

18. The air condenser of claim 12, wherein the tube bundles have spaced-apart ends which are interconnected by the further sidewalls, said further sidewalls being arranged in a V or U-shaped configuration.

19. The air condenser of claim 12, wherein the cells delimit a straight cylinder space when arranged stacked on top of one another, said fan being arranged above the cylinder space.

20. The air condenser of claim 12, further comprising a steam manifold arranged between the parallel rows of cells.

21. The air condenser of claim 12, further comprising a steam manifold which extends above the cells.