DE102012108992A1 - Method for operating air-cooled condensing system of steam turbine plant, involves determining that majority of steam pipe system of air-cooled condensing system contains external gas - Google Patents

Abstract

The method involves determining that a majority of a steam pipe system of an air-cooled condensing system (1) contains external gas. The steam is introduced from a steam circuit of a steam turbine plant to a steam turbine (6) through a bypass line (5). The pressure and temperature of the steam are conditioned previously. The external gas is expelled with the conditioned steam through an exhaust valve (7) in an inlet area (8) of the air-cooled condensing system. An independent claim is included for an air-cooled condensing system with a seam distributing section.

Description

The invention relates to a method for operating an air-cooled condensing apparatus for recovering the steam from a steam turbine plant. In particular, the invention relates to a start-up strategy for such an air-cooled condenser, which is not yet sufficiently flooded with steam. Furthermore, a simply constructed and quickly activated air-cooled condensing apparatus itself is proposed.

In the steam turbine cycle, the achievable vacuum at the end of the steam turbine plays the decisive role in the performance and efficiency of the steam turbine plant. For this purpose, the steam cycle is equipped with a so-called "cold end", where the exhaust steam of the steam turbine is condensed and then recycled to the circuit.

The cold end is formed in many older power plants by wet or evaporative coolers, which effectively dissipate the heat of condensation, but at the expense of high cooling water consumption. In addition, special waste is generated that can damage the environment.

For this reason - especially with the emergence of the combined gas and steam power plants (or "GuD") - the so-called "dry" recooling has prevailed, in which the exhaust steam of the steam turbine in finned tubes is condensed directly on the surrounding air. This dry heat transfer process is less effective than evaporative cooling, but has the advantage of producing no environmentally damaging residues. Dry air-cooled condensation plants - also known as "Luko" for short - have a comparatively large construction volume that must be kept in a vacuum. Due to leaks in the range of steam turbine and flanges and / or by residues from the water treatment of the water-steam cycle regularly accumulate non-condensable (inert) gases to be removed from the vapor space to maintain the vacuum. This is done by the so-called "operation evacuation", which is designed only for the normally very small amount of leakage air.

The situation is different when starting such an air-cooled condensation plant. Here it can be assumed that the entire construction volume is filled with air. Before the steam turbine operation can be recorded in a vacuum, therefore, a large part of the air must first be removed in the vacuum steam space. So far, the so-called "start-up evacuation", which brings the total volume within a predetermined time to a vacuum of about 25 kPa [kiloPascal]. In order to avoid extreme costs for the start-up evacuation, generally a start-up time of about 30 to 45 minutes has prevailed. This minimum time before commissioning of the air-cooled condensing plant and the steam turbine prevents the use of such air-cooled condensing plants in power plants that are designed for short start-up times.

Another difficulty arises in air-cooled condensation systems of large size. In partial load operation, it may be necessary to shut down parts of the condenser. This is usually done by shutting off a heat exchanger section (eg a roof with several parallel roofs) by means of shut-off valves. In order to prevent an inert gas break-in and to enable a quick restart, however, the passive heat exchanger section must still be kept in a vacuum.

If the entire air-cooled condensation plant was shut down together with the steam turbine and the operation evacuation continued to operate for rapid restart, the steam turbine stuffing boxes would have to be steamed to avoid the relatively large air ingress there and to keep a low pressure to restart. This high cost is avoided as a rule, and so it comes to standstill ingress of ambient air in the evacuated volume.

For the planned future increased use of wind turbines and solar energy systems, the task is to be able to rely quickly on replacement energy supplies in case of failure of these energy sources in order to keep the power grid stable. In order to be able to use power plant blocks with environmentally friendly air-cooled condensers here as well, it is a task to be able to start them up in case of need for a short time.

The invention has for its object to alleviate or eliminate the problems mentioned above. In particular, the availability of power plant units should be increased, in particular (but not only) for CCGT plants. Furthermore, the technical complexity compared to the conventional design should be reduced by a new approach strategy.

These objects are achieved with a method for operating an air-cooled condensation apparatus of a steam turbine plant according to claim 1 and an air-cooled condensation apparatus according to claim 7. Further advantageous embodiments of the invention are specified in the dependent claims. The description, in particular in connection with Figures, explains the invention and leads to further advantageous embodiments of the invention.

• – Feststellen, dass ein Großteil des Dampfleitungssystems des luftgekühlten Kondensationsapparates ein Fremdgas enthält,
• – Einleiten von Dampf aus einem Dampfkreislauf der Dampfturbinenanlage über eine Bypassleitung an einer Dampfturbine vorbei, wobei der Dampf hinsichtlich Druck und Temperatur zuvor konditioniert wird,
• – Austreiben des Fremdgases mit dem konditionierten Dampf über mindestens ein Entlüftungsventil im Einlassbereich des luftgekühlten Kondensationsapparates und mindestens ein dem luftgekühlten Kondensationsapparat nachgelagertes Entlüftungsventil,
• – Feststellen eines Dampfdrucks im Bereich des luftgekühlten Kondensationsapparates, wobei in Abhängigkeit des festgestellten Dampfdrucks zumindest die Konditionierung des Dampfes aus der Bypassleitung oder die Menge des Dampfes aus der Bypassleitung eingestellt wird.

The method for operating an air-cooled condensing apparatus of a steam turbine plant comprises at least the following steps:

• Determining that a majority of the vapor line system of the air-cooled condensing apparatus contains a foreign gas,
• Introducing steam from a steam cycle of the steam turbine plant via a bypass line past a steam turbine, the steam being conditioned in terms of pressure and temperature beforehand,
• Expelling the foreign gas with the conditioned steam via at least one venting valve in the inlet region of the air-cooled condensation apparatus and at least one venting valve downstream of the air-cooled condensation apparatus,
• - Determining a vapor pressure in the region of the air-cooled condensing apparatus, wherein at least the conditioning of the steam from the bypass line or the amount of steam from the bypass line is adjusted depending on the detected vapor pressure.

The method for operating an air-cooled condensing apparatus (Luko) of a steam turbine plant relates in particular to a so-called start-up method of an air-cooled vacuum condensing apparatus (in particular one of the following processes of operation: method for producing the normal operation, method for generating a suitable vacuum, method for expelling foreign gases of a ventilated condensing apparatus). This means in particular the operating state in which the condensation plant was completely vented after a standstill (ie atmospheric pressure is present).

Accordingly, as a first step, it can be considered that a majority of the vapor line system of the air-cooled (vacuum) condensing apparatus contains a foreign gas. As already stated in the introduction, inclusions of foreign gas may also occur in normal operation, these quantities or volumes being relatively small compared with the vapor stream. The opposite is found here that a large part of the steam line system contains foreign gas, with a large part z. B. at least 30%, in particular 50% or even at least 80% of the content of the steam line system (eg., Starting from the steam turbine to the condensate tank) detected. In order to determine whether there is a foreign gas in the steam line system, on the one hand the current or previous operating state of the condensing apparatus and / or the steam turbine plant can be used (eg standstill, interruption of operation, valve positions, etc.). Alternatively and / or cumulatively, it is preferable to measure the foreign gas content in the steam line system (determining the pressure and / or the temperature in the steam line system). A particularly simple way to determine if a foreign gas has entered the Luko is to measure the absolute pressure and the local steam temperature. Because of the saturation line of water vapor pressure and temperature are firmly linked. Now, if the measured temperature is below the saturation temperature, a foreign gas must be present. It is also said that the vapor mixture is "undercooled", with increasing subcooling, a higher level of foreign gases is present.

The vapor line system of the air-cooled condenser includes at least one inlet section (eg, steam manifold), heat exchanger sections (particularly with finned tubes), and a downstream condensate section with a condensate tank. Furthermore, the steam line system may also include the steam lines leading up to the outlet of the steam turbine. It is also possible that the management of a separate, used in normal operation Evakuierungsleitungssystems are also included. By "foreign gas" is meant in particular air and / or at least one inert gas.

Basically, it is irrelevant for the application of the process, which structure of the air-cooled (vacuum) condensing apparatus has. However, particularly preferred are roof-shaped condensation apparatus, each comprising a plurality of finned tubes, which can be flowed around by ambient air for cooling. In such a roof-shaped structure, a steam distribution pipe is provided approximately centrally above, wherein the sloping roof surfaces are each subjected to steam, and at the foot end of each collecting ducts are formed for the condensate.

In the event that a start-up of the air-cooled vacuum condensation apparatus is required here, steam from the steam cycle of the steam turbine plant is introduced via a bypass line past a steam turbine, the steam being conditioned in terms of pressure and temperature beforehand. Depending on the steam turbine plant, one or more steam turbine stages can be used. Therefore, in principle, steam from the different areas of the steam cycle can be guided past the steam turbine and introduced into the steam line system of the air-cooled condensation apparatus. The steam should be conditioned in terms of pressure and temperature so that it does not damage the condensing apparatus or even destroyed. Thus, usual pressures in the steam cycle of about 30 be reduced to 40 bar or more here to about 1.0 to 1.2 bar. For this purpose, suitable pressure reducer (bypass valves) can be used. In addition, the temperature of the relaxed live steam should be reduced by injecting condensate to the desired level suitable for the condenser. The temperature of the conditioned steam supplied via the bypass line should not significantly exceed 120 ° C. It is preferred here that the introduction of the conditioned steam via the bypass line takes place near an outlet of the steam turbine, so that as far as possible the entire steam line system of the air-cooled condensation apparatus is flooded or flowed with this preconditioned steam. The skilled person is clear, however, that the bypass line can also open at any other point.

With the introduction of the conditioned steam, the foreign gas previously present therein is now expelled via at least one venting valve in the inlet region of the air-cooled condensation apparatus and at least one venting valve downstream of the air-cooled condensation apparatus. As it flows through the steam through the steam line system, the foreign gas therein is expelled, the conditioned steam first reaches the vent valve in the inlet area (eg on the steam manifold) and later then the vent valve in the condensate, so that due to this targeted flow of foreign gas a predominant part is expelled and now a vacuum operation is readily possible below.

For the purpose of complete and very rapid evacuation of the air-cooled condenser (eg, in less than 20 minutes or even less than 10 minutes), the process repeatedly or continuously detects the vapor pressure in the area of the air-cooled condenser during the process the determined vapor pressure, the conditioning and / or the amount of steam from the bypass line is adjusted. For this purpose, in particular, a control unit is provided with which the vapor pressure and / or the temperature at the outlet of the bypass line is adjusted so that the desired limits for the capacitor are never exceeded. Depending on these limit values, the preconditioning of the steam and / or the introduction quantity can then be regulated. Thus, for example, the enthalpy and / or the pressure of the steam can be varied. Alternatively or cumulatively, the amount (mass flow, volume flow) of the steam from the bypass line can be adjusted. For the latter case controllable valves are provided which can prevent the supply of steam from the steam circuit in the steam line system of the air-cooled condensing apparatus.

In other words, the solution of the problems initially stated is also to use steam for pre-evacuation of an air-cooled condensation apparatus. This steam is introduced via the existing bypass into the steam line and displaces there the collected inert gases, essentially air at atmospheric pressure. The amount of steam may be withdrawn from the mid or high pressure portion of the steam cycle and is brought down by injecting condensate to the enthalpy level of steam at about 110 ° C so as not to endanger the condensing apparatus component. In order to prevent a pressure rise above about 1.3 bar there, the amount of steam flowed in is regulated accordingly.

The steam from the bypass line is now distributed continuously in the entire system. In this case, all "dead branches" (dead ends) should have at their end a corresponding vent valve, in particular with respective examination of the outlet temperature. Each of these vent valves is closed (individually) as soon as an outlet temperature of at least 100 ° C is reached. When all the bleed valves are closed, fans are turned on and the equipment quickly goes into vacuum.

After the steam has reached the tube bundles with the finned tubes, the initially small amount of steam can be increased, because now condensation already takes place in the bundles, which lowers the pressure in the system. Now, when practically operating conditions are present, as desired in normal operation of the air-cooled condensing apparatus downstream of a steam turbine (vacuum operation), the bypass can be closed and normal operation can be started.

Thus, a significant reduction in the start-up time can be achieved, for example, in a combined cycle plant by at least 50% or even by at least 70% compared to the known methods mentioned above. This represents a considerable step forward because it reduces energy and costs while relieving the burden on the environment.

According to an advantageous development of the method, the at least one vent valve closes when a predetermined limit temperature is reached. Then the cooling of the air-cooled condensing apparatus is activated.

As already explained above, the conditioned steam reaches when passing through the steam line system z. B. first the inlet area of the air-cooled condensing apparatus. Now it is recognized that the steam has reached the inlet area and the vent valve is to close. This ensures that the steam generated with high technical effort is not released unused to the environment. This can, for example, be achieved metrologically by measuring the temperature in the area of this venting valve and / or by controlling the venting valve itself to be temperature-regulating. If a temperature of, for example, 100 ° C is reached (limit temperature), therefore closes the vent valve, because such a temperature is a clear indication that (hot) steam is in the range of this vent valve. Furthermore, with the aim of terminating the start-up procedure as quickly as possible, the active cooling can then be used (simultaneously or immediately below), with ventilation units in particular being approached or put into operation. By raising the cooling air fans so the pressure level is lowered by condensation to a desired starting pressure of, for example, 25 kPa. With the aim of using as little steam as possible for this start-up process, the cooling should only be activated when all existing or intended for this purpose bleed valves are closed, so there is already steam.

According to a development of the method, the bypass line is closed and steam is supplied via the steam turbine to the air-cooled condensation apparatus (normal operation) when the determined vapor pressure in the region of the air-cooled condensation apparatus falls below a predetermined vacuum limit.

This vacuum limit value is often specified by the steam turbine used, because it requires a corresponding vacuum (eg 25 kPa) in order to be able to work properly and permanently.

In this case, it is particularly preferred that the steam flow supplied via the steam turbine is supplied with such an increase that the mass flow through the air-cooled condensation apparatus reaches 6 times the value by no later than two minutes.

In other words, this means, in particular, that in turn can be raised very quickly after closing the bypass line of the passed steam mass flow through the steam turbine. If, for example, not more than 10 kg / s [kilograms per second] of steam is supplied during the start-up strategy (CCGT block 400MWe, evacuation volume 4,300 m ³ ), then the inflowing steam quantity can reach quickly when the vacuum limit value (25 kPa) is reached be raised to, for example, more than 80 kg / s, 100 kg / s or even 120 kg / s. It is very particularly preferred that the abovementioned quantities of steam are already reached within one (1) minute.

The method is also considered to be advantageous if venting of the vapor line system of the air-cooled condensing apparatus during normal operation via a separate Evakuierungsleitungssystem.

The so-called "operational evacuation" compensates (only) for the air leaks which normally occur during normal operation, such as occur, for example, due to leaks in the area of the steam turbine and / or flanges of the steam line system. Such "operation evacuation" is widely known and therefore needs no further explanation here.

However, it is clear that the method is tuned so that the startup process, a flooding of the system (only) via the bypass line, while the separate Evakuierungsleitungssystem only serves to suck during normal operation air and / or inert gases (foreign gases).

Furthermore, it is considered advantageous that the foreign gases are expelled by means of the steam introduced via the bypass line via at least one further vent valve at least one of the following positions: at the outlet of the steam turbine, on a condensate tank downstream of the air-cooled condensing apparatus, a line of the separate evacuation line system , a line of a steam turbine downstream drainage system.

It is very particularly preferred that at least one such, suitable for this purpose and set up vent valve is provided at each "closed end" of the steam line system. This takes into account the idea that the conditioned steam, starting from the mouth of the bypass line, is distributed in all directions in the steam line system, so that any foreign gases present therein are now displaced to each end. There, therefore, a vent valve is provided in a corresponding manner, which in turn is in turn thermally regulated, ie automatically closes upon detection of an elevated temperature (steam).

According to a further aspect of the invention, an air-cooled (vacuum) condensation apparatus is proposed, which is provided and submitted in particular for carrying out the method according to the invention.

• – einen Einlassbereich für Dampf mit einem Dampfverteilungsabschnitt mit mindestens einem Entlüftungsventil,
• – einen ersten Wärmetauscherabschnitt und einen zweiten so genannten Dephlegmator-Wärmetauscherabschnitt,
• – eine Ventilationseinheit,
• – ein mit dem Dephlegmator-Wärmetauscherabschnitt verbundenes separates Evakuierungsleitungssystem,
• – einen Kondensatbereich nachfolgend den Wärmetauscherabschnitten.

The air-cooled condensation apparatus comprises at least:

• An inlet area for steam with a steam distribution section with at least one ventilation valve,
• A first heat exchanger section and a second so-called dephlegmator heat exchanger section,
• A ventilation unit,
• A separate evacuation conduit system connected to the dephlegmator heat exchanger section,
• - A condensate area following the heat exchanger sections.

This air-cooled condensation apparatus is, in particular, a roof-shaped and, if appropriate, module-constructed, vacuum condensation apparatus for condensing steam with air. The inlet region is formed, in particular, by a central steam distributor tube, which here forms the steam distributor section of the steam line system. Depending on the length or size of the condensation apparatus several vent valves can be positioned here.

The slopes of the roof are formed with tube bundles having a plurality of finned tubes. In most of these tube bundles a pure condensation takes place, these tube bundle packages are here each marked with a "first heat exchanger section". About this first heat exchanger sections can be formed or removed up to 90% of the condensate. Only a small partial area, the so-called dephlegmator heat exchanger section, has a somewhat different flow path of the steam (for example countercurrent flow) and collects the foreign gases in this respect. This dephlegmator heat exchanger section preferably only affects about 15-10% of the area through which the vapor flows. It should also be pointed out here that, if necessary, a plurality of modules of such roof structures are assembled into very large air-cooled condensing apparatuses, wherein each module regularly has a corresponding structure with first heat exchanger sections and second so-called dephlegmator heat exchanger sections, even if this is not mandatory. In another common design, the function of the first heat exchanger section and the second dephlegmator heat exchanger section is distributed to different modules. Preferably, at least one ventilation unit is assigned to each of these modules. This ambient air is sucked and passed through the heat exchanger sections or the finned tubes of the tube bundle. When sweeping the surface, the ambient air absorbs heat, which is carried in the interior of the finned tubes with the steam. As a result, the condensation of the steam to water takes place in the condensation apparatus.

Connected to the dephlegmator heat exchanger section is a separate evacuation line system with which the foreign gases can be sucked off and removed during vacuum operation. If necessary, with extracted steam can also be recovered in this Evakuierungsleitungssystem. The resulting condensate is also recycled. However, this separate Evakuierungsleitungssystem is just not designed so that it is able to perform a startup process (alone), so it is particularly not suitable to discharge large volumes of foreign gases.

Furthermore, a condensate area is provided downstream of the heat exchanger sections, wherein the latter in particular comprises water pipes and a corresponding water tank or condensate tank. On this basis, the condensate can now be pumped off and fed to the steam cycle again.

It is therefore essential, in particular, that the air-cooled condensation apparatus proposed here itself has no starting device or starting evacuation, as otherwise required. Such a start evacuation is easy to identify by a person skilled in the art, because they usually have (compared to the operation evacuation) particularly thick exhaust pipes with silencer. This equipment expense can be avoided here.

Further vent valves may, for example, be provided on the condensate tank. Since these modules are usually also offered and distributed independently of the steam turbine cycle, the skilled person can easily see that a corresponding starting device is missing, as is usually the case, and instead correspondingly adapted and equipped ventilation valves are provided.

As a vent valve, e.g. Up to average nominal diameter of the steam line (up to 100 mm), a solenoid valve may be provided. Especially for larger nominal diameter, the vent valve can be designed with a flap with actuator. A temperature sensor in front of the vent valve can then trigger the signal to close.

The technical features of such an air-cooled condensation apparatus explained in connection with the method according to the invention and / or the features explained below with reference to the figures can additionally be used in this embodiment according to the invention. Features that have been discussed in connection with the method can therefore also be used in the device and vice versa.

The invention and the technical environment will be explained in more detail with reference to FIGS. The figures are of a schematic nature, wherein the same components have been regularly provided in different figures with the same reference numerals. Show it:

1 : schematically an example of a steam turbine plant,

2 schematically an example of an air-cooled condensing apparatus, and

3 : an example of an air-cooled condensation apparatus according to the invention.

1 schematically shows the structure of a steam turbine plant 2 , It is first steam in a boiler 22 generated and this steam then flows through the steam line system 3 , In the embodiment shown here are two stages of a steam turbine 6 and a reheater 23 illustrates the part of the steam cycle 4 are. In this case, the energy obtained when flowing through the steam turbine can be supplied to a generator or the like. Upstream of the first stage of the steam turbine 6 (High pressure) and / or upstream of the second or last stage of the steam turbine 6 (Low pressure) can be a bypass line 5 branch off to the steam pipe system 3 below the steam turbine 6 but in front of the air-cooled condensation apparatus 1 empties. Part of the bypass line 5 is a conditioner 26 in which the bypass line 5 through-flowing steam can be treated specifically with regard to condensate content, pressure, temperature, etc. The bypass line 5 Here, for example, is near the mouth to the steam line system 3 closed by means of suitable valves. The steam flowing through the steam turbine in normal operation is then in the air-cooled condensation apparatus 1 condensed in a vacuum, the condensate then via a pump 24 again the kettle 22 can be supplied.

In 2 is now a variant of the right figure component from 1 shown larger and illustrated. In the upper left area of 2 is again the low pressure stage of the steam turbine 6 to recognize, to which a line 13 for the steam (see black arrow) connects. At a (geodesic) low point of the line 13 is, for example, a drainage system 14 provided, here on the line 13 condensed steam can already be removed. Between this steam turbine 6 and an inlet area 8th the air-cooled condensing apparatus 1 is here schematically the mouth of a bypass line 5 indicated.

In normal operation, the steam flows through the inlet area according to the black arrows 8th in the first heat exchanger sections 16 of the condensation apparatus 1 , In the embodiment variant illustrated here, two respective first heat exchanger sections are on the left and right sides 16 and centrally a single second (countercurrent or dephlegmator) heat exchanger section 17 intended. These heat exchanger sections, routinely through a variety of finned tubes 25 are formed roof-shaped on a frame 31 arranged and flow through the first heat exchanger sections 16 from top to bottom. In the second heat exchanger section 17 In the manner of a dephlegmator, a reverse or other flow deflection is realized (countercurrent of steam and condensate), so that, for example, foreign gases collect here in the upper region. These can then be operated by a separate evacuation pipe system 10 be removed or sucked off. The cooling of the steam takes place via at least one, but regularly a plurality of ventilation units 18 that together have a cooling 9 for the air-cooled condensation apparatus 1 form. That in the heat exchanger sections 16 . 17 Condensate formed is then a condensate tank 12 fed, the total in the steam line system 3 recovered condensate if necessary together by means of a pump 24 can be dissipated. Between the line 13 upstream of the heat exchanger sections 16 . 17 and the condensate tank 12 can be a pressure equalization line 20 be provided, but here has no special function for the inventive method or the device according to the invention.

The approach strategy, after which steam, for example, after a restart via the bypass line 5 is added, allows the vacuum production and expulsion of the plant or the line 13 air at that time via a plurality of bleed valves 7 , for example, in the inlet area 8th the air-cooled condensing apparatus 1 and on the condensate tank 12 are provided. If the steam reaches the respective vent valves 7 , so they preferably close, so that in fact essentially only air from these vent valves 7 escapes.

3 illustrates in a slightly greater detail schematically a further embodiment of the invention. Beginning on the left again is the steam pipe system 3 with the (last) steam turbine 6 indicated. The from the steam turbine 6 Tapped energy becomes a generator here 21 fed.

If one follows the steam line system or the line 13 , so here, for example, includes a drainage system 14 on before the mouths of the bypass lines 5 be achieved. Here are a (first) bypass line 5 with a high pressure area and another (second) bypass line connected to a low pressure region of the steam line system of the steam turbine plant. In the flow direction of the steam then follows a pressure equalization line 20 that with the condensate tank 12 connected is.

The steam pipe system 3 or the line 13 then hits the inlet area 8th a roof-shaped air-cooled vacuum condensation apparatus 1 , The inlet area 8th is here, for example, formed with a steam distribution pipe, which is positioned centrally above. Underneath are oblique arrangements of finned tubes to the right and left 25 on, depending on the arrangement or design, a first heat exchanger section 16 or a second (dephlegmator) heat exchanger section 17 form. When flowing through these heat exchanger sections 16 . 17 and at the same time activated ventilation units 18 gets the steam in the finned tubes 25 Condensed under vacuum (pressures less than 25 kPa). The condensate then flows off or is passed on to the condensate tank 12 ,

During operation, foreign gases (inert gas, air, etc.) entering the system are fed via a separate evacuation pipe system 10 sucked off, this evacuation pipe system 10 (only) with the second (dephlegmator) heat exchanger section 17 connected is. Part of this evacuation pipeline system 10 is a steam jet 27 , with which the vapor volume drawn there is also condensed and recycled. Even if here is a two-stage steam jet 27 is shown with an additional heat exchanger, such an evacuation pipe system 10 not be structured accordingly. There are also known designs in which instead of the steam jet water ring pumps are used.

The device outlined here is now in particular adapted to carry out the method according to the invention. If, for example, it is found that in a majority of the (shown here) steam line system 3 or the line 13 and / or the finned tubes 25 Air is included, this apparatus must first be raised or transferred to the vacuum state. For this purpose, steam is transmitted via at least one of the two bypass lines 5 into the pipe 13 introduced.

The preconditioned steam then flows, for example, toward the steam turbine 6 , here again a vent valve 7 at the outlet 11 the steam turbine 6 is provided, through which the air can escape.

Likewise, part of the steam introduced can go to the drainage system 14 flow, and here is a vent valve 7 can be provided.

Furthermore, it is the steam possible, along the pressure equalization line 20 in the condensate tank 12 to flow, and here also to remove the air (or other foreign gases) correspondingly suitable vent valves 7 can be provided.

However, much of the steam introduced can be in the inlet area 8th reach, in which case already the entire upstream line 13 is released from air. At the inlet area 8th is therefore, for example, a variety of vent valves 7 provided, over which the from the line 13 originating air is expelled. As soon as steam is here (for example by means of a temperature sensor 28 ) is detected, the vent valves 7 (offset or simultaneous) closed, so that now the steam continues the heat exchanger sections 16 . 17 flows through and can drive out the air there. The smaller part of the steam introduced is through the finned tubes and the downstream lines of the condensate area 19 in the condensate tank 12 flow, again with vent valves 7 on the condensate tank 12 to remove the air.

The greater part of the over the bypass line 5 incoming steam reaches the separate evacuation pipe system 10 , Wherein also at the end of a suitable vent valve 7 can be provided.

All vent valves are preferred in common that they are temperature controlled. This means, in particular, that they automatically close at an reached limit temperature, eg approx. 100 ° C. After reaching vacuum operation, the re-opening of the closed ventilation valves is prevented until the next restart.

The start-up procedure is in particular by a (possibly separate) control unit 30 regulated. Thus, for example, pressure and / or temperature in the air-cooled condensation apparatus 1 by means of at least one temperature sensor 28 and / or at least one pressure sensor 29 be monitored or determined. The control unit 30 uses the knowledge in particular to control or regulate the conditioning and / or the inflow of the steam through the bypass line 5 ,

For the avoidance of doubt, it should be noted that the technical features jointly shown in the figures do not necessarily have to be combined with each other. Rather, the figures show technical details that can be individually combined with technical details of other figures and / or explanations further up easily by the expert. A combination of features should only be considered mandatory if explicitly stated.

The invention leads in particular to solve the above-mentioned tasks. In particular, the invention achieves that at a restart of the steam turbine plant very quickly available again for the air-cooled vacuum condensing apparatus operating conditions, so that normal operation is possible.

LIST OF REFERENCE NUMBERS

1

 air-cooled condensation apparatus

2

 steam turbine plant

3

 Steam circuit

4

 Steam cycle

5

 bypass line

6

 steam turbine

7

 vent valve

8th

 inlet area

9

 cooling

10

 Evacuation line system

11

 outlet

12

 Condensate tank

13

 management

14

 drainage system

15

 Steam distribution section

16

 first heat exchanger section

17

 second (dephlegmator) heat exchanger section

18

 ventilation unit

19

 condensate field

20

 Pressure equalizing line

21

 generator

22

 boiler

23

 reheater

24

 pump

25

 finned tube

26

 conditioner

27

 steam cleaner

28

 temperature sensor

29

 pressure sensor

30

 control unit

31

 frame

Claims (7)

Method for operating an air-cooled condensation apparatus ( 1 ) of a steam turbine plant ( 2 ), comprising at least the following steps: - determining that a major part of the steam piping system ( 3 ) of the air-cooled condensation apparatus ( 1 ) contains a foreign gas, - introducing steam from a steam cycle ( 3 ) of the steam turbine plant ( 2 ) via a bypass line ( 5 ) on a steam turbine ( 6 ), wherein the steam is conditioned in terms of pressure and temperature before, - expelling the foreign gas with the conditioned steam via at least one vent valve ( 7 ) in the inlet area ( 8th ) of the air-cooled condensation apparatus ( 1 ) and at least one air-cooled condensing apparatus ( 1 ) downstream vent valve ( 7 ), - determining a vapor pressure in the region of the air-cooled condensation apparatus ( 1 ), wherein depending on the detected vapor pressure at least the conditioning of the steam from the bypass line ( 5 ) or the amount of steam from the bypass line ( 5 ) is set. Method according to claim 1, wherein the at least one venting valve ( 7 ) closes when a predetermined limit temperature is reached, and then the cooling ( 9 ) of the air-cooled condensation apparatus ( 1 ) is activated. Method according to one of the preceding claims, in which the bypass line ( 5 ) and steam over the steam turbine ( 6 ) the air-cooled condensation apparatus ( 1 ) is fed (normal operation) when the detected vapor pressure in the region of the air-cooled condensation apparatus ( 1 ) falls below a predetermined vacuum limit. Method according to claim 3, in which the steam turbine ( 6 ) is supplied with an increase such that, within two minutes at the latest, the mass flow through the air-cooled condensation apparatus ( 1 ) reaches 6 times the value. Method according to one of the preceding claims, in which a venting of the steam line system ( 3 ) of the air-cooled condensation apparatus ( 1 ) during normal operation via a separate evacuation piping system ( 10 ) he follows. Method according to one of the preceding claims, in which the foreign gases by means of the bypass line ( 5 ) introduced steam via at least one other vent valve ( 7 ) are expelled in at least one of the following locations: at the outlet ( 11 ) of the steam turbine ( 6 ), on an air-cooled condensing apparatus ( 1 ) downstream condensate tank ( 12 ), a line ( 13 ) of the separate evacuation pipeline ( 10 ), a line ( 13 ) one of the steam turbine ( 6 ) downstream drainage system ( 14 ). Air-cooled condensing apparatus ( 1 ), comprising at least: - an inlet area ( 8th ) for steam with a steam distribution section ( 15 ) with at least one venting valve ( 7 ), - a first heat exchanger section ( 16 ) and a second so-called dephlegmator heat exchanger section ( 17 ), - a ventilation unit ( 18 ), - one with the dephlegmator heat exchanger section ( 17 ) separate evacuation pipeline system ( 15 ), - a condensate area ( 19 ) following the heat exchanger sections ( 16 . 17 ).

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