Water-repellent coating in in-built condensers

0001The present invention relates to a method for producing a condenser for a thermal power plant. The invention further relates to a device for coating a built-in condenser tube with a hydrophobic coating.

Background of the Invention

0002In a steam turbine, the total enthalpy of water vapor is used to convert thermal energy, for example from atomic energy, coal or other energy sources, into mechanical energy. Steam is provided from a liquid working medium, such as water, in a steam generator and fed to a turbine. In this turbine, an enthalpy difference of the steam can be used to generate mechanical energy. A condenser or a steam condenser is arranged downstream of the turbine in order to provide isobaric condensation of the water vapor.

0003Surface condensers for steam turbine systems are known as steam condensation, the surface condensers having a large number of uncoated condenser tubes. Film condensation usually takes place on the condenser tubes, which are filled with a cooling working medium, so that the liquid vapor changes into a liquid state of matter.

0004Furthermore, the condenser tubes can be coated hydrophobically in order to provide a targeted transition from film condensation to drop condensation. A drop condensation can be used to increase the heat transfer, which results in an improvement in the heat transfer coefficient of approximately 20%. This in turn leads to an improvement in the efficiency of the capacitor (smaller scale) or to a reduction in costs and installation space with the same scale.

0005<patcit id="pcit0001" dnum="DE102007008038A1"><text>DE 10 2007 008 038 A1</text></patcit> discloses a method with which heat exchanger tubes are sprayed with a hydrophobic layer. The hydrophobic layer can be sprayed onto the condenser tubes via nozzles, the nozzles having flexible feed lines and being arranged and fastened next to one another in an articulated chain. In particular, the nozzles are attached to nozzle lances and can be pushed into a tube bundle. Furthermore, the device has a tensioning device which can be attached and detached to a support plate of the condenser tube bundle.

0006<patcit id="pcit0002" dnum="DE102007015450A1"><text>DE 10 2007 015 450 A1</text></patcit> discloses a coating for steam condensers. This coating consists in particular of a hydrophobic coating. The coating is applied using a sol-gel process.

0007<patcit id="pcit0003" dnum="GB2428604A"><text>GB 24 28 604 A</text></patcit> discloses an antifouling coating on a heat exchanger. A coating can be applied, for example, using a sol-gel process or using a dipping method.

Presentation of the invention

0008It is an object of the invention to provide a capacitor with an improved efficiency.

0009The object is achieved with the features of the independent claims, in particular by means of a method for producing a condenser for a thermal power plant, and a device for coating a built-in condenser tube with a hydrophobic coating.

0010According to a first exemplary embodiment of the present invention, a method for producing a capacitor for a thermal power plant is described. A condenser tube is installed in a carrier for a condenser tube bundle of the condenser. The built-in condenser tube is coated with a hydrophobic coating.

0011According to a further exemplary embodiment, a device for coating a built-in condenser tube with a hydrophobic coating according to the manufacturing methods described above is created. The device has a spray head for coating the built-in condenser tube with the hydrophobic coating.

0012According to a further exemplary or not claimed embodiment of the present invention, a condenser for a thermal power plant is created. The capacitor is manufactured using the method described above. The capacitor has a carrier with a built-in condenser tube, the built-in condenser tube having a hydrophobic coating.

0013The term “condenser tube bundle” can be understood to mean a condenser tube or a multiplicity of condenser tubes which are held in a carrier (condenser tube carrier) at a certain distance from one another and form a condenser tube unit or the condenser tube bundle. A water vapor to be cooled can strike a condenser tube bundle, for example, so that the water vapor can flow past the individual condenser tubes through the condenser tube bundle. The carrier can also be designed to space the individual condenser tubes at a defined distance, so that the water vapor can flow through between the condenser tubes and be cooled by the condenser tubes. The carrier can consist, for example, of tube sheets and supporting walls which have bores and receiving units to which the individual condenser tubes can be attached.

0014The term “hydrophobic” or “hydrophobic coating” can be understood to mean a surface which is water-repellent or on which drop condensation can take place. In addition, the term “hydrophobic coating” can also be understood below to mean a coating which has an oleophobic effect, that is to say which has an oil-repellent effect. A hydrophobic coating has a contact angle with liquid drops of over 90 °. The contact angle can reach up to 130 ° for hydrophobic coatings. With structured surfaces, a superhydrophobic effect with a contact angle of greater than 130 ° or greater than 160 ° (degrees) can be achieved (eg lotus effect). The contact angle defines an angle between a surface of a coating and a vector running tangentially to a liquid drop in the contact point of the drop with a component surface. With a contact angle of over 90 °, a drop shape is formed on a surface with a water drop, so that drop condensation can be provided with a contact angle of over 90 °.

0015Usually, condenser tubes are coated before installation in the carrier and inserted into the carrier for the condenser tube bundle after coating. However, inserting or installing the already coated condenser tubes can damage the hydrophobic coating. Hydrophobic coatings have sensitive properties, so that there is low abrasion resistance and the risk of injury to the hydrophobic coatings on the condenser tubes is high during installation. Coating the condenser tubes with superhydrophobic layers (e.g. Coating with a "lotus effect"), such superhydrophobic layers being particularly sensitive to mechanical stress, so that subsequent installation of the coated condenser tubes leads to a high risk of coating damage. In addition to the insertion of the condenser tubes, the coating can also be damaged by the fastening methods of the condenser tubes on the carrier of the condenser tube bundle. Condenser tubes are welded to the carrier, for example, which can damage the hydrophobic coating. In addition, a high level of maintenance is required to retrofit hydrophobically coated condenser tubes by means of tube exchange, so that long maintenance and set-up times exist.

0016A hydrophobic coating is applied to an installed condenser tube by means of the claimed production process. In other words, the hydrophobic coating is applied to a condenser tube already fastened in a condenser tube bundle. There is thus the possibility of treating a capacitor that is being produced in a single coating process, so that the capacitor tubes of the capacitor can be provided with the hydrophobic coating in one work step, which can reduce the production time. In addition, a hydrophobic coating can be renewed during later maintenance operations of the condensers without having to remove the individual condenser tubes.

0017In the claimed manufacturing method of the condenser, only a part of condenser tubes can be coated in the installed state and another part of condenser tubes can remain uncoated. For example, the outer tubes of a condenser tube bundle make the greatest contribution to the condensation performance of the condenser. Therefore, the advantages of the invention can already be achieved by first installing the outer condenser tubes in the carrier of the condenser tube bundle and coating them with the hydrophobic coating in an installed state. Thus at least the outer condenser tubes of the condenser tube bundle have a high quality hydrophobic coating. Since these outer condenser tubes located at the edge of the carrier provide the strongest condensation performance of the condenser, it is particularly advantageous to provide a high-quality hydrophobic coating, especially with these condenser tubes. It is thus possible to achieve a higher condensation capacity of the condenser without removing the condenser tubes.

0018There is also an improved service option and a better retrofit option (maintenance or retrofit option). This can be an important factor, especially for a power plant operator, since a short shutdown of the steam turbine or the condenser without significant assembly work leads to a significant improvement in efficiency. Furthermore, an attractive business field in the service area can be provided for the manufacturer of the steam turbine.

0019By applying the coating of the condenser tubes in the installed state, a choice of the coating can also be made without taking into account installation matters. In the case of coated condenser tubes in particular, consideration must be given to the fact that, for example, the coating comes into contact with fastening means on the carrier, which leads to wear of the coating. A complex insertion process of the condenser tubes through a series of fastening bores has hitherto been able to rule out a possible use of the mechanically less stable structured hydrophobic coatings. Subsequent coating of the built-in condenser tubes by means of the claimed production process thus enables hydrophobic coatings to be applied to the condenser tubes, so that a further improvement in the condensation properties can be achieved.

0020Furthermore, the coating of the installed condenser tube with the hydrophobic coating has at least one positioning of a spray device on the carrier or relative to the carrier. A spraying of the hydrophobic coating is then provided by means of the spraying device in order to coat the installed condenser tube with the hydrophobic coating. Due to the very fine spray dust of the hydrophobic coating dimensions, the spray painting enables a particularly thin and uniform application of the hydrophobic coating to the built-in condenser tube.

0021In addition, the step of coating the installed condenser tube with the hydrophobic coating comprises moving the spraying device during spraying with a uniform feed along an extension direction of the installed condenser tube. Thus, uniform spraying or coating of the installed condenser tube can be provided automatically. Especially with manual application of a coating, irregular manual feed can lead to irregularities in the spray application of the hydrophobic coating, so that different layer thicknesses are achieved on the condenser tube. By using the spray device, which provides a uniform feed, a predefined and uniform layer thickness of the hydrophobic coating can be provided, so that predefined and improved condenser effects of the condenser tube can be achieved. Furthermore, a multiplicity of layers of the hydrophobic coating can be applied by repeated processes with the uniform feed. For example, a hydrophobic coating can consist of 10, 12 or more sublayers. In addition to a uniform feed along a direction of extension of the installed condenser, a uniform feed orthogonal to the direction of extension of the installed condenser tube can also be provided.

0022According to a further exemplary embodiment of the method, the capacitor is mounted on the thermal power plant during coating and has already been in operation, for example, before the coating process. The power plant operator can therefore carry out a repair or application of the hydrophobic coating on the installed condenser tube without emptying the condenser tubes and thus with minimal effort. An expansion of the condenser tube and thus an interruption in the operation of the condenser can be avoided.

0023According to a further exemplary embodiment, the built-in condenser tube is coated with the hydrophobic coating by means of a brush coating. By means of the coating, a condenser tube can be coated in a simple and quick manner by means of the hydrophobic coating. For example, brush devices can be used for the coating.

0024According to a further exemplary embodiment, the spray device has a spray head, the coating of the built-in condenser tube with the hydrophobic coating further comprising the step of inserting the spray head into the carrier in order to coat the built-in condenser tube with the hydrophobic coating.

0025The term “inserting” the spray head into the carrier can describe that in addition to spraying the outer condenser tubes of the condenser tube bundle, a possibility is also provided for coating the inside of a condenser tube bundle. The spray head can be introduced into the carrier in such a way that the spray head can be passed between the condenser tube spacings and can thus coat internal condenser tubes which, for example, have no direct connection to the surroundings of the condenser tube bundle. This means that even concealed condenser tubes can be coated with the hydrophobic coating in the installed state, so that it is also not necessary to remove these interior tubes. The spray device can be positioned, for example, on or in the carrier of the condenser tube bundle and can provide a spray application of the coating by means of the uniform feed along the condenser tubes.

0026According to a further exemplary embodiment, the step of coating the installed condenser tube with the hydrophobic coating further comprises coating the installed condenser tube by means of electro-spray painting. Electrospray painting can be used, for example, to improve the degree of coating by means of electrostatic effects. In the process of electrospray painting, the spray of the hydrophobic coating can be electrostatically charged during the application, for example with 35 kV (kilovolts), 40 kV or 50 kV, and sprayed onto earthed condenser tubes. The condenser tubes are connected to an earth potential. For example, the carrier of the condenser tube bundle can be a metallic conductor and can thus be used as an electrically conductive structural component. The condenser tubes themselves or the electrically conductive structural components can be provided with a connection to the ground (earthing, earth potential). The hydrophobic coating can be charged electrostatically, for example, with a voltage source. Thus, the advantage of electrospray painting is that the hydrophobic coating is evenly distributed, for example when spraying, and the loss of material in the hydrophobic coating can also be reduced. Furthermore, when the hydrophobic coating is applied to the condenser tubes by means of electro-spray painting, all-round coating of the condenser tubes is made possible. If, for example, the spray head is on one side of the condenser tube, the spray can nevertheless settle on the opposite side of the condenser tubes due to the electrostatic charge, so that a hydrophobic coating can also be provided at opposite locations on the condenser tubes. In electro-spray painting, a predefined thin and uniform hydrophobic coating can be provided on the condenser tubes by means of a suitable choice of the dosage of the hydrophobic coating and with a suitable choice of the feed or the applied static voltage, so that predefined hydrophobic properties can be provided on each of the condenser tubes.

0027According to a further exemplary embodiment, the hydrophobic coating on the installed condenser tube is crosslinked by means of UV curing, dual cure and / or thermal curing.

0028The term “crosslinking” can be understood to mean a connection of the coating to a surface of the condenser tubes. The term "crosslinking" can mean that the coating is firmly connected to the surface of the condenser tubes. This is made possible, for example, by the fact that the molecules of the coating combine with the atoms / molecules of the condenser tube surface or that molecules of the coating engage in cavities in the surface of the condenser tube and thus create a firm connection.

0029During UV curing, an ultraviolet (UV) light is emitted in the direction of the coating by means of a UV lamp, so that the coating is crosslinked due to the excitation of the molecules in the coating and due to the temperature that arises.

0030Another technology for crosslinking by means of UV curing is the dual cure process, in which curing is initially initiated by UV radiation and then the hydrophobic coating is completely cured at room temperature, so that crosslinking takes place.

0031Furthermore, the term "thermal curing" describes crosslinking by curing due to the application of thermal energy. The temperature ranges during thermal curing can be between 50 ° C to 100 ° C or in the range between 100 ° C and 200 ° C or between 100 ° C and 250 ° C. The thermal energy can be applied, for example, by means of radiant heaters, heating coils, resistance heaters or warm air blowers. Furthermore, the thermal energy for curing can be achieved by means of a heating fluid in the condenser tubes, so that no further thermal energy sources can be required. On the other hand, the working fluid can be drained in the condenser tubes in order to avoid an adverse heat capacity of a fluid-filled tube.

0032According to a further exemplary embodiment, a sol-gel process is used in the step of coating the installed condenser tube with the hydrophobic coating. When coating by means of the sol-gel process, hydrophobic coatings are used which have a sol-gel structure. Such sol-gel-based hydrophobic coatings are based on hybrid polymers which have a network structure with organic and inorganic components. Organically modified metal oxides such as Si, Ti, Zr or Al alkoxides can be used as the starting material for the production of such sol-gel coatings. Si alkoxides can preferably be used as precursors which have, for example, the following chemical structure:<maths id="math0001" num=""><math display="block"><mi>Xn</mi><mo>-</mo><mi>Si</mi><mo>-</mo><mfenced><mi>OR</mi></mfenced><mspace width="1em" /><mn>4</mn><mo>-</mo><mi mathvariant="normal">n</mi></math><img file="EP2184115B1_D0001.tif" /></maths>in which:<ul id="ul0001" list-style="none" compact="compact"><li>X = organic modification of the alkoxide</li><li>R = alkyl group (e.g. methyl, ethyl) or aryl group (e.g. phenyl)</li></ul>

0033X (organic modification of the alkoxide) can be a reactive or non-reactive side chain. The coating is produced by hydrolysis and condensation of the metal alkoxides. The organic modification of the metal oxide can influence the properties of the coating. The hydrophobic side chains X (e.g. alkyl chains, alkyl groups, fluoro-alkyl chains, siloxane groups) reduce the surface energy of the coating and produce a water (hydrophobic) and oil (oleophobic) repellent effect. The organic modification can have sufficient water vapor stability.

0034The described hydrophobic sol-gel-based coating material can be further modified by incorporating surface-treated nano- or microscale particles, which can, for example, improve the mechanical abrasion resistance or the corrosion resistance.

0035The hydrophobic sol-gel coatings can be applied to the substrate (condenser tube) in the sol-gel process, for example by wet chemical processes such as spraying, dipping, flooding, rolling or brushing. The coatings are then thermally cured or crosslinked. For example, the temperature ranges of the crosslinking step described above can be used, but a curing temperature in temperature ranges from room temperature to 400 ° C (Celsius) is also possible. A higher curing temperature above 400 ° C can lead to a glass-like layer, whereby the hydrophobic properties can be reduced. Furthermore, short-chain side groups, such as X = methyl groups, aryl groups, sufficient thermal stability. Furthermore, a layer thickness in a range from 100 nm (nanometer) to 100 μm (micrometer) can be achieved.

0036The hydrophobic coating on the built-in condenser tube can be applied by means of the sol-gel process in such a way that, for example, the contact angle of the hydrophobic coating is 90 ° (degrees), 100 ° or 120 °. In comparison to untreated metal surfaces or tube surfaces of the condenser tubes, the use of a hydrophobic coating with a contact angle between 90 ° and 130 °, in particular between, for example, 100 ° and 120 °, approx. 20 % more condensate collected, which can significantly improve the condenser performance of the condenser.

0037According to a further exemplary embodiment, the condenser is a steam condenser and the thermal power plant is a steam turbine plant.

0038According to a further exemplary embodiment of the present invention, the device for coating a built-in condenser tube with the hydrophobic coating according to the production method described above has a positioning device for positioning the device relative to the carrier of the condenser tube bundle. Furthermore, the device has a movement device for moving the spray head along and / or transversely to an extension direction of the condenser tube. The positioning device can, for example, be an independent unit and can be fixed relative to the carrier. On the other hand, the positioning device can be attached to the carrier itself and hold the coating device. The device for coating the installed condenser tube can be, for example, the spray device.

0039Furthermore, the coating device has the spray head for coating the built-in condenser tube with the hydrophobic coating. The spray head can consist, for example, of a nozzle, which can apply the hydrophobic coating in a fine atomization to a surface of the condenser tubes. The movement device can be movably connected to the positioning device and can be moved along a predefined linear movement direction, so that the spray head can be used to provide a uniform application of the hydrophobic coating on the condenser tubes.

0040According to a further exemplary embodiment of the device, the spray head is set up in such a way that the hydrophobic coating can be applied to the built-in condenser tube by means of electrospray painting. For example, the spray head can be connected to a voltage source and thus electrostatically charge a spray of the hydrophobic coating.

0041According to a further exemplary embodiment, the device for coating the installed condenser tube has a connecting tube. The connecting pipe can connect the movement device and the spray head. The connecting tube has a helical shape, the slope of the helical shape being adaptable to a condenser tube radius and to the condenser tube spacings of the condenser tubes in the condenser tube bundle. In other words, the helical shape of the connecting pipe describes a helical line, similar to a corkscrew. On the one hand, the slope of the helix shape at the condenser tube radii and at the condenser tube spacings can be predefined and the spray head can be screwed or screwed in along the condenser tubes by rotating the connecting tube. The connecting tube can thus already be firmly adapted to the condenser tube radii and the condenser tube spacings during its manufacture. In another embodiment, the connecting tube can be made of an elastic material or deformable material, such as rubber, so that during the rotation of the connecting tube in the condenser tube bundle, the connecting tube adapts to the condenser tube radii and the condenser tube spacings and thus forms the helical shape. With the adaptable connecting tube, it is possible to provide an option for coating an existing condenser tube bundle comprising a multiplicity of condenser tubes with a hydrophobic coating. This means that even condenser tubes inside the condenser tube bundle can be coated with the hydrophobic coating. It is therefore no longer necessary to remove the condenser tubes on the inside and thus concealed from the condenser tube bundle in order to provide a hydrophobic coating for the condenser tubes.

0042According to a further exemplary embodiment, the capacitor is designed as a heating capacitor. A heating condenser can be understood to mean a condenser which is supplied with a higher vapor pressure in order to shift the condensation point of the vapor into higher temperature ranges. The high steam pressure in the heating condenser can be generated, for example, by taking steam at a high pressure and high temperature from a turbine stage of a thermal power plant and then feeding it to the heating condenser. With the proposed technical solution, the roughness (ie the temperature difference between a primary and secondary return temperature) of the heating condensers can be reduced (i.e. their function can be improved or restored), whereby a slightly higher temperature of the heat transfer medium (fluid of the district heating network) can be achieved with the same heating steam parameters. On the other hand, a smaller heat exchanger area can be used (cost and / or space savings) or the performance of an existing heat exchanger can be increased with the same degree of roughness.

0043According to a further exemplary embodiment, the condenser is designed as a high-pressure preheater or as a low-pressure preheater.

0044A low-pressure preheater can, for example, be arranged in front of a feed water tank and the working fluid (eg water) can be obtained in the condensed liquid state from so-called condensate pumps. In addition, steam under pressure can be removed from the steam turbines and fed to the low-pressure preheater. This increases the temperature level of the working fluid in the low pressure preheater and thus also in the subsequent feed water tank. This increase in the temperature level increases the efficiency of the steam cycle in the thermal power plant. Here too, the new solution achieves an improvement / restoration of the function and / or a reduction in costs and / or an increase in the performance of the apparatus.

0045A high-pressure preheater can be arranged between the feed water tank and the steam generator of the thermal power plant. Similar to the low-pressure preheater, the high-pressure preheater is supplied with hot steam from the steam turbines under (higher) pressure. The energy level, in particular the temperature level, of the feed water entering the steam generator is thus increased. This can increase the efficiency of the steam cycle in the thermal power plant. Improvements in function, cost and / or performance can be achieved in a similar way to the low pressure preheater.

0046According to a further exemplary embodiment of the capacitor, it is used in the thermal power plant of a thermal power station. A combined heat and power plant is used to generate electricity and heat using a combined heat and power process. The branched-off heat of the steam circuit in the thermal power station can be dissipated to a working medium of a district heating circuit via the condenser (for example designed as a heating condenser) or another heat exchanger. In a cogeneration plant with a combined heat and power process, the unused waste heat can thus be used in a district heating system for further use.

0047It is pointed out that embodiments of the invention have been described with reference to different subject matter of the invention. In particular, some embodiments of the invention are described with device claims and other embodiments of the invention with method claims.

Brief description of the drawings

0048Exemplary embodiments are described in more detail below for further explanation and for a better understanding of the present invention with reference to the attached drawing. Show it:<ul id="ul0002" list-style="none"><li><figref idref="f0001">Fig. 1</figref> a schematic representation of a condenser tube bundle with a hydrophobic coating according to an embodiment of the present invention;</li><li><figref idref="f0002">Fig. 2</figref> a plan view of condenser tubes in a condenser tube bundle according to an embodiment of the present invention; and</li><li><figref idref="f0002">Fig. 3</figref> an exemplary embodiment of condenser tubes which are treated by means of electrospray painting.</li></ul>

0049DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS The same or similar components are provided with the same reference numbers in the figures. The representations in the figures are schematic and not to scale.

0050<figref idref="f0001">Fig. 1</figref> shows an exemplary embodiment of a condenser 100, for example a steam condenser 100, for a thermal power plant, for example a steam turbine plant. The capacitor 100 can be coated with a hydrophobic coating using the production method described. The condenser 100 has a carrier 105 in which built-in condenser tubes 101 are fastened. A built-in condenser tube 101 has a hydrophobic coating.

0051According to the method for producing the condenser 100 for a steam turbine installation, a condenser tube 101 is first installed in the carrier 105 for a condenser tube bundle 203 of the condenser 100. The built-in condenser tube 101 is coated with a hydrophobic coating.

0052The carrier 105 can be used to hold and fasten each of the condenser tubes 101, so that the condenser tube bundle 203 can be provided from the plurality of attached condenser tubes 101. The condenser tube bundle 203 has outer condenser tubes 101 and inner condenser tubes 101, which have no contact with the surroundings of the condenser tube bundle 203.

0053When the condenser 100 is in operation, the built-in condenser tubes 101 have a cooling fluid, for example cooling water, in order to provide condensation of the water vapor by cooling a water vapor flowing past. The hydrophobic coating of the built-in condenser tubes 101 also causes droplet condensation of the water vapor flowing past.

0054According to the manufacturing method described, the spray device 106 can be used to apply a hydrophobic coating to the condenser tubes 101. When the hydrophobic coating is applied, the condenser tubes 101 are already in an installed state on the carrier 105, so that a time-consuming removal for coating the condenser tubes 101 is not necessary. Furthermore, it is avoided that the hydrophobic coating of a condenser tube 101 is damaged when it is installed.

0055The spray device 106 can, for example, have a spray head 102 with which a hydrophobic coating can be sprayed onto the condenser tubes 101. A defined spray cone 104 is thereby formed. In addition to spraying the condenser tubes 101 by means of a spray head 102, a brush coating, for example by means of brush devices, is also possible.

0056On the one hand can the spray head 102 can be moved along the longitudinal direction (extension direction) of the outer condenser tubes 101, so that at least the outer condenser tubes 101 can be applied with the hydrophobic coating. Furthermore, the spray head 102 of the spray device 106 can be made so small that the spray head 102 can be inserted between a condenser tube spacing a. Thus, the spray device 106 can also coat at least the second row of the condenser tubes 101 in the condenser tube bundle 203 with a hydrophobic coating.

0057In a further exemplary embodiment, the spraying device 106 can have a connecting tube 103, so that all the condenser tubes 101 on the inside of the condenser tube bundle 203 can also be coated with the hydrophobic coating in an installed state. The connecting tube 103 can have a helical shape (helix), the pitch of the helix being selected such that the pitch adjusts to the condenser tube radii r and to the condenser tube spacing a.

0058It can thus be achieved that the spray head 102 is screwed into the condenser tube bundle 203 by rotating the connecting tube 103. Each internal condenser tube 101 can thus be coated by means of the hydrophobic coating.

0059<figref idref="f0002">Fig. 2</figref> illustrates a top view of installed condenser tubes 101 in the condenser tube bundle 203. The carrier 105 of the condenser tube bundles 203 has, for example, a condenser tube base 202 and a multiplicity of supporting walls 201 in order to hold the condenser tubes 101. The hydrophobic coating can be applied either along the longitudinal direction or along the transverse direction of the condenser tubes. Along the transverse or longitudinal direction of the condenser tubes 101, the spray device 106 can apply the hydrophobic coating either in one direction or alternately. Furthermore, the spray device 106 can be moved along the longitudinal direction or the transverse direction of the condenser tubes 101. The spray device 106 can move the spray head alternately or alternately in a direction along the direction of extension of the condenser tubes 101 or along the transverse direction. A mixture of both directions of movement (along the direction of extension and along the transverse direction) is also possible. Here, for example, the spray device 106 can be positioned along a positioning device or can be moved by a movement device and during the process the spray head 102 can rotate transversely relative to the direction of movement of the spray device 106 or can perform a pitching movement, so that a mixture of two spray directions is made possible. This enables the hydrophobic coating to be applied quickly.

0060<figref idref="f0002">Fig. 3</figref> shows an exemplary embodiment of a structure for applying the hydrophobic coating by means of electrospray painting. The condenser tubes 101 or the carrier 105 can be electrically conductive and thus represent electrically conductive structural components 303. These electrically conductive structural components 303 can be connected to a ground potential 302. The spray device 106 and / or the spray head 102 are connected to a voltage source 301, so that the spray of the hydrophobic coating can be charged electrostatically, for example with 30 kV, 40 kV, 50 kV or 60 kV (kilovolts). Due to the grounded condenser tubes 101, the electrostatically charged spray of the hydrophobic coating is attracted, so that the spray is evenly applied to the condenser tubes 101. By attracting the electrostatically charged spray of the hydrophobic coating, a built-in condenser tube 101 can be extensively sprayed with the hydrophobic coating. Even if the spray head 102 applies the spray mist to one side of the condenser tube, the spray mist can be attracted due to the electrostatic attraction on the opposite side of the condenser tube 101, so that the hydrophobic coating is also applied to the opposite side. Thus, even when the condenser tubes 101 are difficult to access, a uniform coating of the hydrophobic coating can be provided in the installed state.

0061With the present invention, a condenser tube bundle 203 can thus be provided for a condenser 100, which has built-in and hydrophobically coated condenser tubes 101. Due to the coating of the condenser tubes 101 in the installed state, the manufacturing process of the condenser tube bundle 203 can be accelerated, since the coating process does not have to be carried out individually for each condenser tube 101, but once for the entirety of the installed condenser tubes 101. In addition, in the course of the maintenance of a condenser 100 that is already mounted on the steam turbine system and is in operation, a coating of the condenser tubes 101 can be provided without the condenser tubes 101 having to be removed. Damage to the hydrophobic coating that occurs when a condenser tube 101 is installed in the carrier 105 of the condenser tube bundle 203 can also be avoided since the condenser tubes 101 are coated with the hydrophobic coating only after the condenser tubes 101 have been installed in the carrier 105 of the condenser tube bundle 203 .

0062In addition, it should be pointed out that "comprehensive" does not exclude other elements or steps and "one" or "an" does not exclude a large number. Reference signs in the claims are not to be viewed as a restriction.