Condensation apparatus

(54) Name: Condensing device for steam turbine power plants

The invention relates to a steam turbine power plant condensing device in which a mixing condenser, surface heat exchanger and air supply means for cooling the condensate by air is provided, a pump for conveying the condensate and a condensate conduit connecting the mixing condenser to the surface heat exchanger.

In thermal power plants and nuclear power plants (so-called nuclear power plants, the steam turbines are, as is generally known, supplied with surface condensers, which are supplied with cooling water from natural sources or after cooling in evaporative coolers such as cooling towers, cooling ponds or streams.

In the evaporative coolers, one part of the water is cooled, while another part is moved by the air flow in the form of drops. In addition, part of the water will usually be drained (so-called slurry) in order to prevent an excessive concentration of salts dissolved in the circulated water.

Said water losses are compensated by the supply of spring water. However, this means that in many places on earth, additional difficulties are encountered due to the lack of water.

To overcome these difficulties, the use of so-called air condensation plants, in which ² the condensate is cooled by air. The steam turbine of the power plant is then equipped with a mixing condenser, in which the condensate is injected, which was previously cooled by means of air in surface heat exchangers in the cooling tower with natural air draft or with fan operation.

In the air condensing plants no heat transfer takes place by evaporation. There is only one air heating, which is why much larger quantities of air are required than at the evaporative cooling tower. In air condensation plants, no water losses occur either. However, during the summer, as the air temperature in the ambient atmosphere increases, the suitably low condensation temperatures can no longer be ensured by means of the air condensation cooler, although their dimensions and downtime costs substantially exceed what applies to the so-called wet cooling towers.

The object of the invention is to overcome these difficulties and to provide a steam turbine power plant condensation device in which air is used for steam condensation, as long as the outside air temperature is sufficiently low. However, when the conditions are such that a suitable steam condensation temperature can no longer be achieved by means of air, in addition to cooling by air, water is also used economically. In this way, even during the hot season a significantly lower steam condensation temperature is achieved and thus also a higher turbine efficiency, without the dimensions and costs having to exceed those applicable at known condensation cooling towers.

The invention is based on a condensation device of the kind initially indicated, which in a known manner comprises a mixing condenser and air-cooled heat exchangers for the condensate arranged in a cooling tower.

According to the invention, the device is characterized in that the surface heat exchangers are provided with vertical cam flanges, over which is arranged a sprinkler assembly, preferably a distributor with irrigation heads, a surface collecting basin being arranged below the heat exchangers, the basin connected to a suction pipe connected to a suction pipe.

Thus, the heat exchangers are provided with vertical cam flanges, which are, for example, radially arranged relative to the cooling tower or form a fixed angle with the radial direction. Thereby, it is achieved that on the surface of the cam flanges, a downwardly flowing, continuous film of water is formed, which is formed of water sprayed from above from the heat exchangers. Through the downstream water film, the heat is absorbed from the heat exchanger's cam flanges and, in addition to convection, is also released by evaporation to the air flowing horizontally along the cam flanges, - thereby making the heat emission considerably more intense.

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The water film should cover the entire surface of the comb flanges and should be as thin as possible, so that no greater thermal resistance occurs in the air during the heat release from the comb flanges. The amount of flowing water must thereby substantially exceed the evaporation losses, so as to avoid too high enrichment of salts and the consequent deposition of tartar. To meet this need, an amount of water of 150 kg / h to 300 kg / h calculated per running meter can be calculated horizontal flange projection on one side.

The dimensions of the cooling unit for the condensate and the heat exchangers and the air supply means are suitably chosen in such a way that a suitably low steam condensation temperature is ensured in winter, even · at maximum load of the power plant, and without the start of the heat exchangers.

Since at air temperatures below the freezing point, temperature differences of the order of 35 ° C to 45 ° C between condensate and air can be allowed without deteriorating the turbine efficiency, the economic dimensions of the heat exchangers and air supply means are substantially smaller than those of the known air condensation plants which the outside air's annual average temperature.

However, at outside air temperatures above freezing point, it is not necessary to spray the heat exchangers, if the power plant does not operate at maximum load, as is the case during the night and on work-free days. The heat exchangers will only be partially sprayed due to increasing air temperature and load on the power plant, whereby the number of sprayed heat exchangers is determined taking into account the prevailing need. At maximum load and high outside air temperature, all heat exchangers can be water sprayed.

The beginning is obviously regulated. A suitable device is defined in claim 2. At the connection points of the water supply lines to the starting devices for the individual heat exchangers and heat exchanger groups, there are arranged regulating means which, depending on the condensate temperature or the pressure prevailing in the turbine condenser, switch on and disconnect the respective switch-off switch.

In this way, the condensing device according to the invention enables a high degree of turbine efficiency to be maintained with the consumption of a minimum amount of water for the evaporation, whereby the amount of water is reduced or increased depending on the weather conditions and the load of the power plant. In this way, the air flow in the cooling tower with natural air draft is utilized fully, whereas the air flow in the cooling tower, on the other hand, at the wet cooling towers and known air condensation plants, is deliberately reduced at air temperatures below the freezing point.

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For example, condensation devices of this type are particularly suitable for use in places of higher latitude and with a strong continental climate, since the average annual water losses at such sites can be reduced to between 1/3 and 1/4 of the losses occurring in wet cooling tower, whereby the turbine efficiency is increased by at least 0.5% without increasing the downtime of the condensing device.

A further advantage of the condensing device according to the invention in comparison with known wet cooling tower condensing devices consists in that dry air and non-humid air flow through during the winter months with air temperatures below freezing, thereby avoiding icing inside the cooling tower and its surroundings. These towers can also be made much easier.

The use of the condensing device according to the invention has special advantages if the power plant is located in the vicinity of the fuel location and the consumers of the electrical energy and if in addition to the water supply it is possible to use sources of less capacity than is the case with known condensation devices with evaporative coolers.

The heat exchangers for the condensate are conveniently made multiple on the water side by supplying the condensate with the last vertical pipe line in the direction of the air flow and the cooled condensate being drained from the first pipe line. Then, in the horizontal direction, the cam flanges will exhibit different temperatures, which increase in the direction of the air flow.

When pouring the heat exchangers, the temperature of the draining vent film will be slightly lower than the temperature of the cam flange at a particular location. Thereby increasing. the temperature of the water film likewise t the direction of the air flow. In this way, a stream located on the air inlet side will be supplied with the coldest water, which can be used in the power plant's oil and gas cooler. The portion of the water collection basin supplied to the coldest water is therefore conveniently separated by a partition between the boundary walls and connected to the suction line to a feed pump which supplies the water to the oil and gas coolers. Such a device is defined in claim 3. In this connection, it can be mentioned that, when using the known air condensing plants, a special cooling water source must be used for the water supply of the oil and gas coolers or a cooling unit with its own evaporative water cooler must be installed.

It is also a known fact that the cooling in heat exchangers with cooling towers with natural air drag is significantly reduced in strong winds, which can be attributed to the reduced draft. This effect can be avoided there5

7213706-0 by providing a helical or helical air flow in the cooling tower. For this purpose, the heat exchangers of the otherwise generally vertically arranged cam flanges may form an angle with the radius of the cooling tower with natural air drag. However, it is also possible that after the heat exchangers, ie downstream of these, there are provided air flow-deflecting means which set the air in helical motion. A device so trained is defined in claim 4.

further features of the invention will be described and explained with reference to the drawing which shows some different embodiments of the condensing device of the invention.

For the figures shown in the drawing, fig. 1 shows the principle connection of the components included in the condensing device according to the invention; fig. 2 shows in perspective a detail of the device; fig. 3 shows different sections through a detail of the device; 4 shows the cross-section of a detail of a second embodiment of the device;

The same reference numerals are used in the figures to denote other similar details.

As shown in Fig. 1, a steam turbine 1 is provided with a mixing condenser 2, which is connected to an air-driven surface heat exchanger 4. over a circulation pump 3 in a conduit 9. The heat exchangers 4 are arranged in the air supply opening in a cooling tower 8. The heat exchangers 4 provided the collecting basin 6, which is connected to an oil and gas cooler 12 over a line 10.

X conduit 10 is provided with a circulation pump 7, which has the task of supplying water distributors 5 arranged above water with heat exchangers 4. A further feed pump 11 provides the water supply of the oil and gas cooler 12.

The illustrated embodiment of the condensing device according to the invention operates as follows

The waste steam from turbine 1 flows to the mixing condenser

2nd Here, the wastewater vapor is condensed by means of over the conduit 9 and the unregulated regulator is supplied, injected condensate and the exact circulation pump 3 is conveyed across the lower branch of the conduit 9 to the air-cooled surface heat exchangers 4. The hot condensate flows through the tubes of the heat exchangers 4 and then returns over the upper branch of the conduit 9 and the unregulated control means back to the mixing condenser 2, wherein the cooled condensate is injected into the supplied waste vapor, which then forms a hot condensate, which is then added again. .

If the outside temperature is now so high, that the air flow through

The natural tower or fan drive cooling tower 8 is no longer able to sufficiently cool the condensate circulated in the heat exchangers 4, the circulation pump 7 is started, so that water from the water collection basin 6 via the line 10 is supplied to the water distributors 5, which the water distributors 5 supply to the water distributors 5. It is shown above those in FIG. 1 not shown in more detail, the cam flanges downstream of the water are collected in the water collection basins 6, whereby the surface heat exchangers 4 are cooled to a great extent to the draining water.

The feed pump 11 transports water from the water collection basins 6 to the oil and gas cooler 12, from which the water is also supplied to the water distributors 5, which is excellent with the exposed flow arrows.

In Figure 2, a part of a surface heat exchanger 4 is shown in perspective.

As can be seen in the figure, the tubes of the heat exchanger 4 carry cam flanges which are arranged vertically. The water distributors 5 are provided with irradiation skin 13. Protective plates 14 prevent water droplets located above the actual heat exchanger 4 from being drawn by the air stream. This is achieved by the fact that the protective plates 14 at the desired location block the flow path of the cooling air. Similar protective plates 15 are provided at the bottom below the heat exchanger 4 in the water collection basin 6. The coldest water collects in a space 16 between the pelvic wall and a partition 15. The flow air is prevented by protective plates 17 from flowing through the heat exchanger 4.

The operation of the illustrated embodiment of the condensing device according to the invention is clearly shown in Fig. 2.

The condensate flows through the horizontally arranged tubes of the heat exchanger 4, which in the figure is indicated by flow arrows. In this way, water flows out of the water distributor.5 via sprinkler heads 13, which water moistens the vertical cam flanges on the horizontally extending pipes.

The draining water reaches the water collection basins 6 in the form of a thin water film, the coldest water collecting in the room 16, since the pipes on this side of the heat exchanger already conduct cooled condensate, so that the cold air entering the arrow direction is only heated to a small extent and the running water has to remove the smaller amount of heat.

In Fig. 3, horizontal sections are shown through the heat exchanger 4 at different heights thereof. 18 denotes a container which is connected to the water collection basin 6. The conduit 10 leads out of the container 18 to an annular distribution line 20, which in turn is connected to the water distributors via regulating means 21. A conduit 22 has the task of distributing the condensate, which via distributor pipes 23 streams⁷ 7213706-0 to the individual heat exchangers 4, and is drained via drain pipe 24 and drain pipe 25.

The illustrated embodiment of the condensing device according to the invention operates as follows:

The condensate flows through the conduit 9, which is also shown in Fig. 1. From the conduit 9, the condensate flows to the distribution conduit 22, from which it enters the individual heat exchangers via the distribution tubes 4. In the tubes of the heat exchangers 4, the hot condensate is cooled by the air flow indicated by arrows. and is drained over the drain pipes 24 and the drain pipe 25. From the drain pipe 25, the cooled condensate flows through the pipe 9 again back to the one in FIG. 3 not shown the mixing condenser 2.

On the other hand, the circulation pump 7 feeds water from the container 18 over the conduit 10 and the regulating means 21 to the water distributors 5, from which the water through the irradiation heads 13 not shown in Fig. 3 reaches the comb flanges of the heat exchangers 4. The draining water collects in the water collection basin 6, the shape of which in the illustrated embodiment corresponds / corresponds to the outer profile of the heat exchangers 4, which relationship is also evident from the upper, right quadrant of Fig. 3. From the water collection basin 6, the draining water flows back into the container 18.

The regulating means 21 arranged at the connection points between the distribution line 20 and the distributors 5 can be set and regulated independently of one another, so that the utilization of cooling by water can be adjusted in accordance with the prevailing needs.

19 denotes air deflection plates, by means of which the air entering the arrow direction can be set into the spiral and the air respectively. helical movement.

In the embodiment of Fig. 4, the vertical cam flanges of the heat exchangers 4 are arranged at an angle to the radial direction of the cooling tower not shown. This means that the spiral or helical air flow can be achieved without the deflection plates 19 shown in the preceding embodiment. Walls 26 denote walls which prevent air flow between adjacent heat exchangers 4.

Above, the invention has been described with reference to such condensing devices, which are provided in steam-powered turbines. However, instead of water vapor, it is also possible to choose steam from any other flow medium whose freezing point and evaporation temperature can be brought into line with the normally prevailing weather conditions.^J

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