JP6021313B2 - Method, power plant, and cooling system for cooling a carrier fluid in a power plant - Google Patents

Description

  The present invention relates to a method for cooling a carrier fluid, which is used to drive a turbine in a power plant. The present invention also relates to a power plant with a carrier circuit having a carrier fluid, said carrier fluid driving the turbine of the power plant during operation. Furthermore, the invention relates to a cooling system for such a power plant.

  A typical way of generating power from heat in a power plant is to bring the carrier fluid to a predetermined heat level, thereby imparting a predetermined level of kinetic energy to the carrier fluid. A carrier fluid such as water evaporates into water vapor. Water brought under a considerable pressure of about 270 bar is converted into water vapor, which means that the volume of the carrier fluid is additionally increased. That is, the steam has sufficient energy to drive a large turbine, and the turbine motion causes the generator to move. After driving the turbine, the steam must be cooled, and this cooling is usually done in a condenser. Such condensers are often heat exchangers with a cooling circuit along which a carrier circuit with a carrier fluid is routed. That is, the carrier circuit is a tube system connected to the turbine, and the cooling circuit is filled with a coolant, which is indirectly contacted with the carrier fluid and before the condensation, the carrier fluid. Is significantly cooler than. A part of the heat of the carrier fluid, i.e. the steam, is thereby transferred to the coolant in the cooling circuit, so that the steam becomes water again.

  In today's power plants that utilize such technology, wet or dry cooling towers are used to cool the temperature in the cooling circuit. In the wet cooling tower, a portion of the coolant, also typically water, is evaporated and released into the air. Other parts of the cooling fluid may be reused in the cooling circuit or released to the river, from which the cooler temperature is cooled in order to supply fresh cooling water at the river temperature to the cooling circuit again. Water may be taken in reverse.

  Such a power plant according to the prior art is shown in FIG. Several components of the power plant 2 are shown schematically in this figure, and the power plant 2 has a carrier circuit 1 and a cooling circuit 11. In the carrier circuit 1, the carrier fluid 5, in this case water 5, in particular water vapor, is pumped through the tubing by the carrier circuit pump 3. A heat exchanger 9 is used to cool the water vapor 5 to a much cooler temperature and change it back into liquid water 5. The condensed water is pumped by the carrier circuit pump 3 and discharged. The heat exchanger 9 is also connected to a cooling circuit 11 having a cooling fluid 13, i.e. cooling water 13. The cooling water 13 is taken from the river 27 and is pumped to the heat exchanger 9 by the cooling circuit pump 23. Before reaching the heat exchanger 9, the cooling water 13 is approximately at the temperature of the river 27. After leaving the heat exchanger 9, the cooling water 13 extracts a lot of heat from the water vapor 5 in the carrier circuit 1. Therefore, the cooling water 13 is significantly hotter than before, and needs to be cooled to return to the river 27. For that purpose, a wet cooling tower 19 is used. Here, while the high-temperature cooling water 13 from the cooling circuit 11 is sprayed into the tower, the air 17 is passed through the cooling tower 19. While this process results in a steam cloud 21, the remaining 25 of the cooling water 13 is returned to the river 27 at a significantly lower temperature level than before entering the wet cooling tower 19.

  According to this principle, a significant part of the cooling water 13 used for condensing the water vapor 5 in the heat exchanger 9 evaporates into the air in the wet cooling tower 19. This provides a very high cooling efficiency as it results in a significantly lower temperature of the remaining portion 25 of the cooling water 13. Since the efficiency of the power plant 2 depends directly on the ability of this cooling system to cool the carrier fluid 5, this type of condenser system provides an overall high power plant efficiency. However, the wet cooling tower consumes a large amount of water. Depending on the ambient conditions, this consumption reaches a value of water far exceeding 500 kg / s for a 500 MW power plant.

  Therefore, an alternative to the wet cooling tower is a so-called dry cooling tower, and its principle will be described with reference to FIG. The dry cooling tower 33 directly cools the carrier fluid 5 in the carrier circuit 1. The carrier fluid 5 comes from the turbine 29 in the power plant 2. The turbine 29 drives a generator 31, and the generator 31 generates electric power from the rotation of the turbine 29. In the dry cooling tower 33, the water 5 is guided in the pipe system 37, and the pipe system 37 functions as a fin / tube heat exchanger. To cool the tubing 37, the blower 35 provides fresh air that is passed around the tubing 37 so that a constant flow of air 17 is guided around the tubing 37. That is, the carrier fluid 5 is slowly cooled in the tube system 37 and can be pumped again by the carrier circuit pump 3 to a heating unit (not shown). Such a heating unit may include a heating chamber in which substances (oil, coal, waste, and other combustible materials) are burned, or may include a nuclear reactor or a solar heat field.

  Although the dry cooling tower 35 does not necessarily require a water supply, the effect of the dry cooling tower is limited by the ambient temperature. High ambient temperatures reduce the efficiency of the thermodynamic process. This is because the condenser temperature in the dry cooling tower 35 and thus the individual pressure at the outlet of the turbine 29 increases.

  It is also possible to combine the wet cooling tower 19 and the dry cooling tower 35 in one power plant. However, some dilemmas still exist for the operation of any power plant based on either or both cooling technologies. In some areas, there is a lack of water, the air is very hot at the peak, or both. Usually both of these phenomena can be seen simultaneously. However, these dry places such as deserts usually have the advantage that much solar energy is readily available. That is, it has proved to be a major challenge to provide an effective cooling system while sufficient heating energy is theoretically available at a very low cost.

  The object of the present invention is to further optimize the cooling process for condensing power plants. In particular, the object of the present invention is to suitably reduce the consumption of water, or indeed any other cooling fluid, during such a cooling process.

  The problem is solved by the method of claim 1, the method of claim 7, and the power plant of claims 13 and 14.

  According to a first embodiment of the invention, the method of the above-mentioned type is characterized in that at least part of the cooling process substantially comprises surrounding the carrier fluid and / or cooling fluid for cooling the carrier fluid. It is improved by being realized by guiding underground to a depth that is lower than air. In other words, an underground area is utilized in which the carrier fluid and / or cooling fluid is cooled. Therefore, the thermal inertia of the underground soil is utilized. Even in the desert, underground soils are relatively cool compared to the daytime ambient temperature above the ground, mainly due to the strong cooling effect at night.

  Two principles may be used for this embodiment. Direct cooling of the carrier fluid can be achieved by directing the carrier circuit of this carrier fluid to the underground area. Indirect cooling means that a cooling fluid, such as water or another fluid having a high heat capacity, is directed to the underground pipe. This cooling fluid then cools the carrier fluid in the heat exchanger.

  The method according to the present invention may be implemented instead of or in addition to using any of such techniques, evaporating or blowing techniques as described above. That is, an underground area below the surface level of the soil in the area of the power plant is used as a cooling area in which the carrier fluid and / or cooling fluid is at least partially cooled.

  Regarding the definition of “underground”, basically any area below the surface of the soil can be considered as underground. For the purposes of the present invention, it is necessary to cool the carrier fluid and / or the cooling fluid and the underground area must be substantially cooler than the ambient air, i.e. above ground. This means that there is a temperature difference of at least 10 ° C., more preferably 20 ° C., between the ambient air and the underground area where cooling takes place. More preferably, the carrier fluid and / or cooling fluid is directed to an underground area at least 0.5 m, more preferably at least 1 m below the surface level of the soil. In this area, the pipe for carrying the fluid is guided along a length, so that the temperature of the underground area effectively absorbs part of the higher temperature of the fluid. The length of such a tube is preferably at least 10 m, more preferably at least 20 m, but the tube does not necessarily have to be guided in only one direction, eg as in a typical heat exchanger You may have a curved part and a meandering part. For carrier fluids and cooling fluids, these may include liquids such as water and / or gases such as air. The carrier fluid and the cooling fluid may be the same material, but may be different materials, for example water as the carrier fluid and oil as the cooling fluid. The cooling circuit through which the cooling fluid is conveyed may have a plurality of separate cooling sub-circuits. For example, the first cooling fluid is cooled by the second cooling fluid in a heat exchanger or the like.

  According to a second embodiment of the invention, such a cooling effect is a method of the kind described above, wherein at least part of the cooling process cools at least part of the carrier fluid and / or the carrier fluid. May be achieved by a method such as realized by supplying at least a portion of the cooling fluid used for storage from a cold reservoir that stores the fluid at a temperature significantly lower than the temperature of the carrier fluid in the turbine. . Such a low-temperature storage unit may be disposed underground as described above, but may be disposed on the ground level and preferably have a thermally insulated container. This container is preferably supplied with a liquid or gas that has been cooled underground. However, it is possible to have a cold storage that receives the fluid at a cold level at night and then stores it at low temperatures during the day. For example, such a cold storage is a large size that is open at night so that the contents (ie, fluid) are cold and is closed and insulated during the day to maintain a low temperature level for as long as possible. It may be realized as a container. The cryogenic storage has a ground and / or underground cooling process (ie according to the first embodiment of the invention, eg by means of air-to-liquid heat exchange, which means using dry cooling technology) ) Can be used to supply the cooled fluid.

  Both main embodiments of the method according to the invention have one common principle, ie the low temperature is stored or provided in one place. In the first embodiment, the low temperature is stored in the underground area at any available low underground temperature. In a second embodiment, the invention utilizes a specially designed container in which low temperatures are artificially stored. In both embodiments of the invention, evaporation techniques are not required and water loss due to cooling and condensation is significantly reduced. In addition to the cooling technique according to the present invention, a blowing technique can be used, but such a blowing technique is not essential.

  Thus, depending on which of the above embodiments is used, a power plant of the type described above can be realized in two different forms, which may be combined or used individually. May be.

  According to a first embodiment of the method according to the invention, a power plant of the kind described above has at least one cooling with cooling fluid used to cool at least part of the carrier circuit and / or the carrier fluid. This can be improved by having part of the circuit led underground to a depth that is substantially cooler than the ambient air.

  For that purpose, the power plant preferably has underground pipes and / or underground tanks. The underground area acts as a “heat sink” or some sort of cold reservoir. Such a tube or tongue is preferably formed from a material having a high heat transfer rate, so that heat transfer from the fluid to the underground area outside the tube or tank is as effective as possible. Accordingly, the heat transfer coefficient of such a tube or tank is preferably greater than 15 W / mK, more preferably greater than 100 W / mK, ie at least in the range of the heat transfer coefficient of metals such as stainless steel. That is, it is most preferable to use an insulated pipe or tank. Heat transfer can be further improved by heat transfer improving means such as a fin tube.

  Second, ie additionally or alternatively, in a power plant of the type described above, at least a part of the carrier fluid and / or at least a part of the cooling fluid used for cooling the carrier fluid is stored cold. This can be improved by storing at a temperature significantly lower than the temperature of the carrier fluid in the turbine.

  Such a cold storage may be realized as a ground level or underground level container or tank. Containers or tanks may be incorporated into power plant buildings to reduce the need for thermal insulation, but may be located outside such buildings to further isolate them from the thermal process. Such containers are preferably insulated, which means that little heat is transferred to the inside of the container, which means that the low temperature is maintained inside the cold storage as long as possible. To do. In particular, the cold storage maintains the temperature of the contents at a predetermined level that is no higher than 20 ° C. below the lowest level during the day. This is suitable for a cold storage in a state where the cold storage is filled with a predetermined fluid for a day when no fluid is fed into the cold storage or taken out of the cold storage. Value.

  As mentioned above, both embodiments of the power plant according to the invention also follow the common principle described in connection with the two embodiments of the method according to the invention. In the combination of these embodiments, the cold storage is supplied underground below the surface of the soil, so that it is not always necessary to have an isolating means. This is because isolation is actually realized by the surrounding soil instead of additional isolation material.

  Finally, the present invention is a cooling system for a power plant, at least a portion of a carrier circuit having a carrier fluid and / or at least one cooling circuit having a cooling fluid utilized to cool the carrier fluid. Is guided underground to a depth that is substantially cooler than ambient air, and / or at least a portion of the carrier fluid and / or at least a portion of the cooling fluid is less than the temperature of the carrier fluid in the turbine. It also relates to a cooling system that is stored in a cold storage at a significantly lower temperature.

  In order to be a power plant according to the present invention in any of the above embodiments, the power plant can be re-equipped with such a cooling system according to the present invention.

  Particularly advantageous embodiments and features of the invention are given by the independent claims, as represented in the following description. Thus, the features expressed in connection with one of the methods are not related to each other method and / or embodiment of the power plant according to the invention, unless expressly stated otherwise. May be implemented in connection with any one of the above.

  It is particularly preferred that the cooling is performed at a power plant in a high temperature environment. Such a high temperature environment is given in particular in a desert environment or a similarly dry environment. These environments can be characterized as reaching a maximum temperature of 40 ° C. for at least 100 days of the year. In this situation, water is particularly scarce. That is, power plant water consumption will compete directly with water demand for food production and urban life, and local life and food production will have the highest priority over power generation. Thus, power plants in such areas can be operated without problems only if they have a very low water consumption footprint, that is, water loss during operation as low as possible. The use of the method according to the invention is particularly useful in order not to waste valuable water for power generation. Such water can now be saved for other purposes, such as agriculture and home use.

  At the same time, the sun's influence in such areas is particularly high. Thus, while such a dry environment offers the possibility of operating a solar power plant, until now there has been a dilemma related to efficient cooling as described in the introductory paragraph. Therefore, cooling is preferably performed for the carrier fluid in solar power plants, particularly concentrating solar power plants. First, such solar power plants are often located in dry areas as described above. Second, such power plants, particularly concentrating solar power plants, generate a very high temperature carrier fluid. Concentrated solar power plants have the characteristic that light rays from the sun are concentrated in small spots, which results in extremely high temperatures at these spots. As a result, the temperature produced by the concentrating solar power plant is particularly high and sufficient for the power generation cycle. However, the efficiency of the cycle is determined by the cold end (condensation) temperature. This temperature determines the lowest pressure achievable at the turbine outlet. The lower the pressure, the higher the efficiency and thus the higher the power output that is extracted from the power plant. This can be improved by the method according to the invention.

  In addition to the cooling achieved by the method according to the invention, additional cooling may be necessary to further cool any of the fluids. The first possibility is that the cooling according to the invention is performed for a carrier fluid in a power plant having an air-cooled condenser or a dry cooling tower that performs part of the cooling. As previously indicated, a dry cooling tower with a blower again has the advantage that essentially no cooling fluid is lost into the air. The combination of the cooling method according to the invention and the cooling method using an air-cooled condenser allows a closed cooling circuit or a closed carrier circuit in which no fluid is lost to the surrounding environment.

  A second possibility, including additional cooling, is that the cooling according to the invention takes place in a power plant with a wet cooling system that performs part of the cooling. The first possibility and the second possibility may actually be combined so that the three cooling systems together provide the overall cooling effect of the carrier fluid and / or cooling fluid. However, the cooling method according to the invention may be combined only with a wet cooling system. This means that the wet cooling tower takes over part of the cooling while the rest of the cooling is performed by the cooling system according to the invention. As mentioned above, wet cooling provides the most effective cooling overall so that a particularly effective system is achieved, in which case the method according to the invention helps to reduce fluid consumption. Whether the wet cooling tower is arranged upstream or downstream of the cooling system according to the invention is selected according to technical priority, according to space availability and depending on other prerequisites can do. However, in some special cases it is preferred to arrange the wet cooling tower downstream of the cooling system according to the invention. This is especially the case when the water loss of the wet cooling tower is reduced by a cooling system that can be improved by such an arrangement of the two cooling systems.

  In short, combining such a variety of different cooling systems with the method according to the present invention provides a system with increased efficiency. It also allows temporary use of any cooling method at various different times. For example, the main cooling circuit consists of a dry cooling tower system, and the cooling system according to the invention is operated during peak hours.

  Although it is possible to simply direct the carrier fluid and / or cooling fluid to the underground pipe system, the carrier fluid and / or cooling fluid is preferably cooled in a heat exchanger connected to a cooling circuit. Such a cooling circuit contains a cooling fluid. The carrier fluid is cooled directly in the heat exchanger or the cooling fluid is cooled in the heat exchanger by a second cooling fluid circulating in the cooling circuit. The latter means that two cooling circuits, both containing cooling fluid, are used together, in which case the cooling fluid in the various different cooling circuits may be of different types but need not necessarily be different.

  For the method according to the second embodiment of the invention (ie using a cold storage), the cold storage is preferably located underground at a depth that is substantially cooler than the ambient air. This means that, in practice, both embodiments of the method according to the invention are combined so that cooling takes place underground in an underground cold storage. This is particularly advantageous because no isolation means are required to securely isolate the cold storage, as is usually the case when the cold storage is on the ground.

  It is particularly preferred that such a cold storage is replenished with fluid at night and is supplied during the day. This means that the carrier fluid and / or cooling fluid can be cooled at night and collected in a cold storage and supplied during the day, especially during the day when the weather is particularly hot.

  Additionally, a portion of the carrier fluid and / or a portion of the cooling fluid can be stored in multiple cold stores. For example, one main cooling store for "normal operation" and a second additional cold store for hours of operation or peak power consumption under harsh conditions such as extremely hot weather May be provided. However, the different cold storage units may be used at different times, for example, on different days, thereby increasing the time for recovering the low temperature in each cold storage unit. Also, all low temperature stores may be used in parallel at any time to provide a combined cooling effect.

  The cooling method according to the invention is particularly effective for times when cooling of the carrier fluid is particularly necessary. Thus, the cooling method according to the invention is most preferably applied under extreme thermal conditions and / or during times of peak power consumption.

  In such extreme conditions, it is further preferred that the use of the cooling method is initiated by the drive unit according to variable input data relating to temperature information and / or power consumption information. Such a drive unit receives information about the ambient temperature and / or information about the current power consumption in the power supply network, and from these information to activate or deactivate these parts of the power plant Instructions are derived and these instructions activate the cooling system according to the invention. For example, a valve for feeding into and / or out of the cooling system according to the invention can be opened and closed according to such a command of the drive unit. This means that the cooling system can be opened and closed according to current demand.

  Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. However, the drawings are drawn for illustrative purposes only and are not drawn to define the scope of the invention.

  In the drawings, like reference numerals designate like objects throughout. Objects in the drawings are not necessarily drawn to scale.

1 is a schematic diagram of a power plant with a first cooling system according to the prior art. FIG. FIG. 2 is a schematic diagram of a power plant with a second cooling system according to the prior art. It is the schematic of the power plant provided with the cooling system by the 1st Embodiment of this invention. It is the schematic of the power plant provided with the cooling system by the 2nd Embodiment of this invention. It is the schematic of the power plant provided with the cooling system by the 3rd Embodiment of this invention. FIG. 6 is a detailed view of a portion of the cooling system of FIG.

  1 and 2 have been described above in connection with the description of the prior art.

  FIG. 3 shows a power plant 2 ′ according to the first embodiment of the present invention. In this and the following figures, other components of the power plant 2 'such as heating chambers, turbines, generators, and power generation systems are not shown for clarity.

  In the cooling circuit 11, the cooling fluid 13, in this case the cooling water 13, is pumped through the pipe system by the cooling circuit pump 3. First, the cooling fluid 13 passes through a dry cooling tower 33 of the type described in connection with FIG. Next, the cooling water 13 is further guided to a depth of 41 underground into the soil below the ground. That is, a part of the cooling circuit 11 is the underground pipe 40, and the cooling water 13 can be cooled at a low temperature at the underground depth 41 in the underground pipe 40. That is, the underground pipe 40 constitutes the cooling system 4. The cooling water 13 is further led to a wet cooling tower 19 of the type shown in FIG. Water vapor exits the wet cooling tower 19 in the form of a vapor cloud 21. The remainder of the cooling water 13 is then collected and pumped to a heat exchanger (not shown) to cool the power plant 2 'carrier fluid.

  While the cooling water 13 can be supplied to the underground pipe 40 and the cooling system 4 via the first valve 59, the direct connection portion 60 that bypasses the underground pipe 40 is opened and closed by the second valve 61. be able to. When the cooling water 13 is cooled in the underground pipe 41, the first valve 59 is opened and the second valve 61 is preferably closed. On the other hand, if the cooling by the dry cooling tower 33 and the wet cooling tower 19 is sufficient to cool the cooling water 13 to the desired low temperature, the second valve 61 can be opened and the underground pipe The first valve 59 can be closed to shut off the connection to. For that purpose, the control unit 63 gives commands SB to both the first valve 59 and the second valve 61, and the two valves are operated by these commands SB. The control unit 63 has an input interface 64 for information data ID, for example information about the ambient temperature of the power plant 2 'and / or the current power consumption of the power grid supplied by the power plant 2'. The drive unit 57 extracts the command SB from these information data IDs, and these commands open and close the first valve 59 and the second valve 61. Therefore, the opening and closing of the valves 59 and 61 depends on these information data IDs provided via the interface 64. In other words, depending on the information data ID, the underground pipe 40 can be blocked or access can be provided. For example, during the daytime under high temperature weather conditions, the information data ID includes information about high temperatures. The information data may include date and time information, from which any expected temperature level can be extracted in arid areas. For example, the information that it is daytime is sufficient to indicate that the desert is at a very high ambient temperature without taking extra temperature measurements in the desert. From the information data ID, the drive unit 57 derives a command SB for opening the first valve 59 and closing the second valve 61 so that additional cooling in the underground pipe 40 is available. The same may be the case at times of extremely high power consumption in the power supply network.

  Such a control unit 63 can be used in any of the following embodiments, as will be described in connection with FIGS. Therefore, the control unit 63 is not shown in the following drawings.

  FIG. 4 shows a power plant 2 ′ according to a second embodiment of the present invention. Also in this case, the cooling water 13 is pumped through the cooling circuit 11 by the pump 3. The cooling water passes through the dry cooling tower 33 as described above before entering the underground depth 41 where the heat exchanger 45 is disposed. The cooling water 13 is cooled in the heat exchanger 45 and further guided to the wet cooling tower 19 as described with reference to FIG. The heat exchanger 45 is supplied with the second cooling liquid 46, and the second cooling liquid 46 is guided through the second cooling circuit 47 by the second cooling circuit pump 49. The second cooling circuit 47 is located at the underground depth 41 so as to be cooled by the underground soil. Therefore, the second cooling circuit 47, together with the heat exchanger 45 and the second cooling circuit pump 49, constitutes the cooling system 4 according to the second embodiment of the present invention.

  FIG. 5 shows a power plant 2 'according to a third embodiment of the present invention. For the sake of clarity, the features common to FIGS. 3 and 4 will not be mentioned again. After exiting the dry cooling tower 33, the cooling water 13 is led again to the underground depth 41 where the low temperature storage part 51 is arranged. Such a low temperature storage unit 51 can also be arranged on the ground when the low temperature storage unit 51 is preferably thermally isolated from the outside.

  The cold storage 51 is shown in more detail in FIG. The low temperature storage unit 51 is realized as a container in which a large amount of the cooling water 13 is stored. In order to cool the cooling water 13, an additional pipe system 53 with a pump 55 is led underground so that the cooling water 13 is cooled underground and returned to the cold storage 51. As shown in FIG. 5, the cooling water 13 returns from the low temperature storage unit 51 to the cooling circuit 11.

  Although the present invention has been disclosed as preferred embodiments and variations, it will be understood that numerous additional modifications can be made without departing from the scope of the invention. As mentioned above, the cold storage can also be located on the ground, and it is absolutely necessary to use a dry cooling tower and / or a wet cooling tower in addition to the cooling system used to implement the method according to the invention. Is not necessary.

  For the sake of clarity, it should be understood that the use of the singular does not exclude a plurality and the expression “comprising” does not exclude other steps or elements throughout this application.

  2 'power plant, 3 cooling circuit pump, 4 cooling system, 11 cooling circuit, 13 cooling water, 21 steam cloud, 33 dry cooling tower, 40 underground pipe, 41 underground depth, 45 heat exchanger, 46 second cooling Liquid, 47 second cooling circuit, 49 second cooling pump, 51 cold storage, 53 additional tubing, 57 drive unit, 59 first valve, 61 second valve, 63 control unit, 64 inputs interface

Claims (14)

In the method of cooling the carrier fluid (5) with water, the carrier fluid (5) is used to drive the turbine (29) at the power plant (2 '), and at least part of the cooling process is carried out by the carrier fluid. (5) is realized by guiding underground to a depth (41) where the soil is substantially cooler than the ambient air, cooling is performed for the carrier fluid (5) in the solar power plant, The depth (41) is selected such that there is a temperature difference of at least 10 ° C. between the ambient air and the underground area where cooling takes place ,
Characterized Rukoto performed cooling in power plants (2 ') having a wet cooling system (19) for performing a part of the cooling process, a method of cooling the carrier fluid (5).   The method according to claim 1, wherein the cooling process is additionally realized by introducing a cooling fluid (13, 16) for cooling the carrier fluid (5) to the depth underground.   The method according to claim 1 or 2, wherein the cooling is performed in a power plant (2 ') in a hot environment.   The method according to claim 1, wherein a concentrating solar power plant is used as the solar power plant.   5. The method as claimed in claim 1, wherein the cooling is performed for a carrier fluid (5) in a power plant (2 ') having an air-cooled condenser (35) for performing part of the cooling. . Carrier fluid (5) and / or cooling fluid (13) is cooled in the cooling circuit connected to the heat exchanger (47) (45), any one process of claim 1 to 5. For the cooling process, the low-temperature reservoir for storing a fluid at a significantly lower temperature than the temperature of the turbine (29) the carrier fluid (5) in providing (51), any one of claims 1 to 6 the method of. The method of claim 7 , wherein the cold storage (51) is located underground at a depth (41) that is substantially cooler than ambient air. The method according to claim 7 or 8 , wherein the cold storage (51) is replenished with fluid at night and is supplied during the day. The method according to any one of claims 7 to 9 , wherein a part of the carrier fluid (5) and / or a part of the cooling fluid (13) is stored in a plurality of cold storages (51). . Cooling method is applied during the time the extreme thermal conditions and / or in the peak power consumption, any one method according to claims 1 to 1 0. Use of the cooling method is initiated by a drive unit (57) according to the variable input data (ID) relating to the temperature information and / or power consumption information, according to claim 1 1 The method according. In a power plant (2 ') comprising a carrier circuit (1) having a carrier fluid (5), the carrier fluid (5) is adapted to drive a power plant turbine (29) during operation;
The carrier fluid (5) comprises water;
-At least part of said carrier circuit (1) is led underground to a depth (41) where the soil is substantially cooler than ambient air , and at least part of the cooling process is carried out , The depth (41) is selected such that there is a temperature difference of at least 10 ° C. between the ambient air and the underground area where cooling takes place ,
Further comprising wherein the Rukoto a wet cooling system (19) for performing a part of the cooling process, the power plant (2 '). 2. A part of at least one cooling circuit having a cooling fluid (13, 46) used to cool the carrier fluid (5) is led underground to the depth (41). 3. The power plant described in 3 .

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