Condensation Plant

Abstract

A condensation plant includes heat exchanger elements (10) which are mounted on a support structure (8) in particular in a roof-shaped manner and to which cooling air (K) is supplied via fans (11). The heat exchanger elements (10) are surrounded by a wind shielding wall (13), with the bottom edge (14) of the wind shielding wall (13) projecting further outwards than the top edge (15) of the wind shielding wall (13).

Description

The invention relates to a condensation plant having the features set forth in claim 1.

Condensation plants are utilized for cooling turbines or process exhaust steam and in use in very large sizes for many years in the energy field. The efficiency of a power plant depends to a not insignificant degree on the condensation capacity of the condensation plant. Local weather conditions and accompanying wind speeds and wind directions have a significant impact on the condensation capacity. Current constructions of condensation plants have wind shielding walls which fully surround the heat exchanger elements to prevent a direct recirculation of the heated cooling air. The wind shielding walls are normally arranged vertically or sometimes even slantingly inclined to the outside, depending on prescribed structural regulations.

It has been found that winds that impact from the side and forced underneath the fans cause a local pressure drop beneath the fans, when the wind speeds are high. The presence of a pressure below atmospheric renders the fans incapable to convey sufficient cooling air, thereby reducing the condensation capacity. As a result, accumulating steam cannot be condensed quickly enough so that the output of a turbine connected to the steam circulation must be reduced in some circumstances.

This problem has been known for some time and has been addressed for example by mounting barriers, so called wind crosses, in the suction space beneath the fans. Wind crosses divide the suction space beneath the fans into single zones. It is to be taken into account hereby that the fans are mounted sometimes at a height of up to 50 m. The wind crosses are normally built to a height of about 30% of this free space so that wind coming from the side cannot flow unimpeded beneath the fans but rather is upwardly deflected, when impacting the wind crosses, and directed to the fans. Even though the wind crosses cause an improvement in efficiency and a reduction of the pressure drop of peripheral fans, the flow against the peripheral fans is oftentimes unsatisfactory.

The invention is based on the object to reduce the adverse effects of winds that flow from the side against a condensation plant mounted to a support structure.

This object is attained by a condensation plant having the features set forth in claim 1.

Advantageous improvements of the invention are the subject matter of the sub-claims.

The object is essentially attained by a wind shielding wall which is arranged at an inclination with respect to the wind direction and has a bottom edge which projects further outwards than the top edge thereof. Model calculations confirmed a reduction of added pressure drops as induced by the wind in the order of at least 10%, regardless whether an additional wind cross is arranged beneath the fans. The advantages are especially brought to bear on the fans arranged on the perimeter of the condensation plant, where the pressure drop could be reduced by about 20%.

The entire wind shielding wall or also only a section of its height may be configured at an inclination. An angle of inclination from 5° to 35°, in particular from 15° to 30°, in relation to a vertical has been considered appropriate. The angle of inclination, however, may not be so great as to cause a significant cross sectional narrowing that hinders an unobstructed flow of the heated cooling air upwards because this would adversely affect the efficiency. For example, a wind shielding wall of a height of about 10 m may be shifted on its top edge by 1 m to 3 m in the direction of the heat exchanger element. As a result, the cross section is decreased only to an insignificant extent. When a respective installation space is made available, the bottom edge of the wind shielding wall may in principle also be shifted to the outside. In this way, the inclination can even be increased, without reducing the flow off cross section. When the wind shielding wall has a height of about 10 m, a maximum lateral offset of 3 m+3 m=6 m would then be possible for example.

In addition, or as an option, the wind shielding wall may be curved concavely in the direction of the heat exchanger elements. Also in this way, a greater portion of the laterally impacting wind is upwardly deflected so that the pressure drop beneath the peripheral fans is smaller. As the volume flow of the upwardly deflected wind increases, an additional barrier of cold air is created which also advantageously counteracts a warm air circulation. The inclination of the wind shielding walls has also advantages in respect to the warm air circulation on the side of the condensation plant that faces away from the wind because the warm air does not flow vertically at the perimeter but flows off further inwards in accordance with the inclination of the wind shielding wall. As a result, the flow path of the recirculating warm air is longer.

In addition, the wind shielding wall may be provided with a horizontal profiling at least in a height zone adjacent to the bottom edge. Wind shielding walls having trapezoidal profiles are typically erected, whereby the profiling extends in vertical direction, i.e. from bottom to top. This alignment of the profiling has a positive effect on the flow behavior insofar as the wind is deflected downwardly or upwardly. However, especially the downward deflection is unwanted. Therefore, at least the height zone adjacent to the bottom edge may have a profiling which provides a flow barrier. The upper height zone of the wind shielding wall may conversely have a vertical profiling so that the upward flow of wind is not impeded.

Exemplary embodiments of the invention will now be described in greater detail with reference to the drawings, in which:

FIG. 1 shows a prior art calculation model of a condensation plant which is impacted from the side and has a vertical wind shielding wall;

FIG. 2 shows a first embodiment of a condensation plant with inclined wind shielding wall; and

FIG. 3 shows a further embodiment of a condensation plant with concavely configured wind shielding wall.

FIG. 1 shows a model calculation of a condensation plant 1 as pertaining to the prior art. Wind W flows in the model calculation from the side against the condensation plant. The heat exchanger elements are not shown in detail. Only the steam manifolds 2 which are associated to the heat exchanger elements can be seen in cross section. The heat exchanger elements are arranged in a roof-shaped manner beneath the steam manifolds 2. Fans 3, shown only schematically, draw cooling air from below, with the heated cooling air flowing past the steam manifolds 2 upwardly. It is clearly shown that not all fans 3 are evenly approached. In particular, the peripheral fan 4 conveys clearly less air than the fans 3 arranged in midsection. The reason is that the laterally incoming wind W impacts a straight wind shielding wall 5 and is partly deflected upwards, i.e. across the condensation plant 1, and partly also into the suction space beneath the fans 3, 4. Through use of a flow barrier 6 as well as a wind cross 7, the flow direction of the wind W can at least partly be changed so that the wind is directed toward the fans 3. This holds true, however, only to a limited extent to the peripheral fans 4. The pressure in a region, labeled ΔP, beneath the fans 4 is smaller than a pressure beneath the other fans 3. In other words, the peripheral fan 4 conveys less cooling air so that the efficiency of the condensation plant 1 is decreased.

This problem is addressed by arranging the wind shielding walls at an inclination, as depicted in FIGS. 2 and 3 by way of example. FIG. 2 shows a greatly simplified representation of the peripheral area of a condensation plant 8 having heat exchanger elements which are arranged on a support structure 9 in several rows in roof-shaped manner and of which only peripheral heat exchanger elements 10 of the outer row are illustrated for the sake of simplicity. Located beneath the heat exchanger elements 10 is a fan 11 which draws cooling air K from below and directs it according to the indicated arrows to the heat exchanger elements 10 where the cooling air K is heated and flows off upwardly in the direction of arrow WL. At the same time, steam from the steam manifold 12 arranged in the top region of the heat exchanger elements 10 is introduced in direction of the arrows D into the heat exchanger elements 10, where the steam condenses.

Essential in this embodiment of a condensation plant is the configuration of the wind shielding wall 13 which is inclined in relation to the vertical V in the exemplary embodiment of FIG. 2. The wind shielding wall 13 has a height extending approximately up to the top edge of the steam manifold 12. The bottom edge 14 of the wind shielding wall 13 projects further outwards than the top edge 15 of the wind shielding wall 13. The angle of inclination NW is in this exemplary embodiment about 5°. Compared to a vertically aligned wind shielding wall, the established inclination of the wind shielding wall 13 enables a greater portion of transversely approaching wind W to be deflected upwards. As a result, the pressure differential APL as measured between the inlet side 16 and the outlet side 17 of the fan 11 is smaller than in the case of vertically oriented wind shielding walls.

The same effect is realized also when the wind shielding wall is not straight but concavely curved, as shown in the embodiment of FIG. 3. Like in FIG. 2, the bottom edge 19 of the wind shielding wall 18 of FIG. 3 projects further outwards than top edge 20 thereof, with the difference residing in that the wind shielding wall 18 is not straight from the bottom edge 19 to the top edge 20 but is curved.

LIST OF REFERENCE SYMBOLS

• 1—condensation plant
• 2—steam manifold
• 3—fan
• 4—fan
• 5—wind shielding wall
• 6—flow barrier
• 7—wind cross
• 8—condensation plant
• 9—support structure
• 10—heat exchanger element
• 11—fan
• 12—steam manifold
• 13—wind shielding wall
• 14—top edge of 13
• 15—bottom edge of 13
• 16—inlet side of 11
• 17—outlet side of 11
• 18—wind shielding wall
• 19—bottom edge of 18
• 20—top edge of 18
• D—steam
• ΔP—pressure differential
• ΔPL—pressure differential
• K—cooling air
• NW—angle of inclination
• V—vertical
• W—wind
• WL—warm air

Claims

1.-4. (canceled)

5. A condensation plant, comprising: a support structure;heat exchanger elements mounted on the support structure;fans for directing cooling air to the heat exchanger elements;a steam manifold for directing steam into the heat exchanger elements; anda wind shielding wall disposed in surrounding relationship to the heat exchanger elements and having a height which extends approximately to an upper edge of the steam manifold, said wind shielding wall having a bottom edge and a top edge, wherein the bottom edge of the wind shielding wall projects further outwards than the top edge of the wind shielding wall.

6. The condensation plant of claim 5, wherein the heat exchanger elements are arranged on the support structure in a roof-shaped manner.

7. The condensation plant of claim 5, wherein the wind shielding wall has at least a section which is inclined at an angle of inclination from 5° to 35° in relation to a vertical.

8. The condensation plant of claim 5, wherein the wind shielding wall has at least a section which is inclined at an angle of inclination from 15° to 30° in relation to a vertical.

9. The condensation plant of claim 5, wherein the wind shielding wall is curved concavely in a direction of the heat exchanger elements.

10. The condensation plant of claim 5, wherein the wind shielding wall has adjacent to the bottom edge at least one section provided with a horizontal profiling.