WO2015078829A1 - Thermal power plant - Google Patents

Abstract

The invention relates to a thermal power plant comprising a cooling system for cooling a thermal working fluid. In order to be able to build a flat cooling system, the cooling system comprises at least one coolant pump (52) for pumping a coolant (68), the pump shaft (56) of the coolant pump extending horizontally.

Description

Description Thermal Power Plant The invention relates to a thermal power plant with a cooling system for cooling a thermal working medium.

In a thermal power plant, heat is partially converted into electrical energy. Examples of thermal power plants are i.a. Coal-fired power plants, natural gas power plants or nuclear power plants. These types of thermal power plants use fossil fuels or nuclear processes as heat sources. Other examples of thermal power plants are geothermal power plants or solar thermal power plants.

In general, a thermal power plant operates according to the following principle: First, heat is removed from a heat source and the heat is transferred to a thermal working medium, e.g. Water / steam, transferred. By means of a heat engine, e.g. a turbine, then a portion of the heat of the thermal working fluid is converted into kinetic energy, which in turn is converted by a generator into electrical energy. Due to physical laws, only a limited part of the heat supplied to the thermal working fluid can be converted into electrical energy in the thermal power plant. The remaining part remains as waste heat in the thermal working means of the thermal power plant.

For maximum efficiency of the thermal power plant, a temperature difference between a minimum and a maximum temperature of the thermal working fluid must be as large as possible. If the working fluid in the thermal power plant goes through a cycle, the waste heat remaining in the thermal working fluid after passing through the heat engine must be removed from the thermal working fluid before it is again supplied with heat from the heat source becomes. For this purpose, the thermal power plant expediently comprises a cooling system for cooling its thermal working medium, which in addition can serve to cool other components of the thermal power plant, such as a generator or a transformer.

The following types of cooling systems for thermal power plants are already known from the prior art: continuous cooling without cooling tower, drain cooling with cooling tower and circulation cooling with cooling tower. All these types of cooling systems will produce water

(Cooling water) used as a coolant, which extracts heat by means of a heat exchanger the thermal working fluid. Regardless of the type of cooling system used, the cooling system requires at least one cooling water pump for conveying the cooling water from / to the heat exchanger. To drive the cooling water pump usually a motor is used. The motor is suitably arranged vertically above the cooling water pump - usually in a building intended to accommodate the cooling water pump and motor ("pump structure") .To keep a drive train short between the engine and the cooling water pump, one endeavors close to the engine and the cooling water pump On the other hand, in order to avoid vibration excitation of the cooling water pump by the engine, which could lead to a resonance catastrophe on the cooling water pump, a minimum distance between the cooling water pump and the engine is necessary.

Consequently, the pump structure in previously known thermal power plants on a large vertical extent.

It is an object of the present invention to provide a thermal power plant, the cooling system may have a flat design. This object is achieved by a thermal power plant of the type mentioned, in which according to the invention, the cooling system comprises at least one coolant pump for conveying a coolant whose pump shaft is aligned horizontally.

The invention is based on the consideration that a vertical extent of a pump structure of the cooling system is significantly dependent on how the pump shaft of the coolant pump is aligned. By a coolant pump with a horizontally oriented pump shaft, a flatter design of the cooling system can be achieved than by a coolant pump with a vertically aligned pump shaft.

The flatter design of the cooling system can i.a. lead to a cost-effective production and / or a shorter construction period of the cooling system, since e.g. a construction of high scaffolding constructions and / or deep excavations for subterranean structures or building sections, in particular foundations, can be omitted.

Furthermore, the invention is based on the recognition that, given a vertical alignment of the pump shaft, possibly a larger delivery height of the coolant pump is required than with a horizontal alignment of the pump shaft. For with a vertical alignment of the pump shaft, if the coolant pump flows parallel to the pump shaft, the coolant must be able to overcome a height difference that is at least equal to a length of the coolant pump. In contrast, with a horizontal alignment of the pump shaft, the difference in height to be overcome by the coolant can be less than the length of the coolant pump. Consequently, in a coolant pump with a horizontally oriented pump shaft, a delivery of the coolant pump may be designed to be lower than in a coolant pump with a vertically aligned pump shaft.

As a coolant pump, a pump can be understood, which is prepared for conveying a coolant. examples for Coolant pumps are: pipe casing pumps, volute casing pumps, submersible pumps. The coolant may be a gaseous and / or a liquid medium. Preferably, liquid water is used as the coolant.

The coolant can circulate in a circuit. Coolant losses may occur in the circuit, e.g. due to leaks in pipes or partial evaporation of the coolant. In order to keep an amount of the coolant in the coolant at least approximately constant, further coolant can be supplied to the coolant circuit from the outside, e.g. from a body of water if water is used as a coolant. Alternatively, the coolant may pass through the cooling system without circulating.

The cooling system may also include a plurality of coolant pumps. The plurality of coolant pumps may be arranged such that they can be flowed through by the coolant in series or in parallel.

A pump shaft may be understood to mean a rotatably mounted machine element of the coolant pump which is used to transmit a torque, in particular a torque generated by a motor, to other machine elements, such as e.g. an impeller, serves. The other machine elements can be arranged on the pump shaft, in particular connected to the pump shaft. Preferably, the pump shaft is configured substantially rod-shaped or cylindrical. Furthermore, the pump shaft may be u.a. be stored one or two sides.

The cooling system expediently includes a coolant supply. As a coolant supply, a device or system can be understood, which is prepared for introducing the coolant into the coolant pump. The coolant supply can in particular be connected directly to the coolant pump. The coolant supply may be, for example, a pipe, a pipe system and / or a basin act. A pipe system may be understood to mean a system comprising a plurality of pipes connected to one another and / or to other elements of the cooling system for guiding the coolant.

Preferably, the coolant supply is designed such that the coolant flows into the coolant pump substantially parallel to the pump shaft. In addition, the cooling system expediently includes a coolant removal. As coolant discharge, a device or system can be understood, which is prepared for discharging the coolant from the coolant pump. The coolant discharge can in particular be connected directly to the coolant pump. The coolant discharge can be, for example, a pipe, a pipe system and / or a tank.

Preferably, the coolant discharge is configured such that the coolant flows out of the coolant pump substantially parallel to the pump shaft.

Conveniently, at least one impeller is arranged on the pump shaft. An impeller can be understood to mean a rotatable component of the coolant pump, in particular a component rotatable with the pump shaft. The impeller may be configured to supply and / or remove kinetic energy from the coolant, in particular by changing the swirl of the coolant.

The impeller may comprise blades ("blades"), which may in particular be arranged in a ring-shaped manner, and the impeller may be mounted on one side of the pump shaft. or cohesively connected to the pump shaft A cohesive connection of impeller and Pump shaft may involve the impeller and the pump shaft being cast in one piece.

It is advantageous if the impeller is an axial wheel. As axial wheel, an impeller can be understood, which is adapted to convey the coolant parallel to the pump shaft (axially). With an impeller configured as an axial wheel, it can be achieved that the coolant can flow through the coolant pump without being deflected. As redirecting, e.g. a change in direction of a

Flow direction of the coolant can be considered by an angle of at least 30 °.

Further, it is advantageous if the impeller has adjustable blades. The blades may e.g. be rotatable about an axis oriented substantially perpendicular to the pump shaft. Due to the adjustability of the rotor blades, it is possible to achieve an angle between the flow direction of the coolant and the rotor blades that can be variably adjusted. By the adjustability of the angle between the flow direction of the coolant and the blades can be achieved that a flow rate / delivery height of the coolant pump is controllable and / or a load torque of the pump shaft, in particular by changing a flow velocity of the coolant, to a constant value is preserved ,

Preferably, such a coolant pump with adjustable blades is a horizontal Kaplan turbine.

In this coolant pump or in the horizontal Kaplan turbine due to their horizontal orientation, a coolant coverage of coolant inlet (inlet level) to installation height / depth of the coolant pump may be lower than in a coolant pump with vertically aligned pump shaft. Large required coolant coverages usually lead to rising costs. In other words, the lying Kaplan turbine requires a low coolant coverage, ie the lying Kaplan turbine can be installed with shallow depth to the coolant supply level. An installation depth of the horizontal Kaplan turbine, defined over its axis of rotation of the pump shaft, to the coolant level in the coolant inlet, for example a feed basin, can be so low.

The pump shaft of the coolant pump may be hollow inside. In the pump shaft, a displaceable, in particular axially displaceable, mounted adjusting rod can be arranged, which is preferably prepared to adjust the blades. The adjusting rod can be driven by a servo motor, which can be arranged in the pump shaft.

In an advantageous development, the coolant pump has a tail. As a tail, the entirety of the components of the coolant pump can be understood, which change the swirl of the coolant before and / or behind the impeller - based on the flow direction of the coolant. It is expedient for the tail unit to comprise a plurality of blades ("guide vanes") .The guide vanes may be arranged in a ring shape to form a so-called guide wheel Preferably, the tail unit is designed to guide the coolant axially to the pump shaft.

In front of the impeller arranged guide vanes can serve to adjust the swirl of the coolant in front of the impeller so that a higher efficiency of the coolant pump can be achieved. Vaned vanes located behind the impeller may serve to reduce the swirl of the coolant while increasing static pressure of the coolant, thereby allowing for reduction of kinetic energy losses associated with coolant flow. Advantageously, the guide vanes of the tail are adjustable - eg by means of a servomotor. This allows a controllable swirl change through the vanes. The guide vanes may, for example, be rotatable about an axis oriented substantially perpendicular to the pump shaft.

Particularly advantageous is thus a horizontal Kaplan turbine in addition with adjustable guide vanes. In addition, the vanes of the empennage are preferably adjustable such that coolant flow through the coolant pump, e.g. for maintenance purposes, can be interrupted. If the cooling system comprises a plurality of coolant pumps, it can be achieved by such an adjustability of the guide vanes that one or more of the coolant pumps can be separated from the coolant circuit, e.g. to reduce the flow rate at a reduced coolant requirement of the thermal power plant. Due to the adjustability of the guide / rotor blades, as in the case of the example lying lying Kaplan turbine with additional adjustable guide vanes, a coolant pressure and / or the flow rate of the coolant pump is variable to the current coolant demand of the thermal power plant customizable. Further, the adjustability of the guide / rotor blades makes it possible that the efficiency of the coolant pump is not only at given working conditions maximum, but can be maximized under different working conditions. The coolant pump always works like a Kaplan turbine in an optimal efficiency range.

Furthermore, due to the adjustability of the guide vanes and the possibility of adaptability of coolant pressure and delivery rate, the coolant coverage may be lower than in the case in which one

Coolant pump is used whose guide / blades are not adjustable. Further, the coolant pump can be designed as a multi-stage pump with a plurality of successively arranged pairs of running and guide wheels, wherein the pairs of running and guide wheels can be flowed through by the coolant in series. As a result, among other things, a delivery height of the coolant pump can be increased, since each stage of running and guide wheels can supply kinetic energy to the coolant.

In an advantageous embodiment, the coolant pump is equipped with a control unit for controlling the flow velocity of the coolant. The control unit can i.a. a flow sensor for measuring the flow velocity of the coolant. The flow sensor is preferably behind the impeller - with respect to the flow direction of the coolant - arranged.

Further, the control unit may be part of a control system for automatically controlling a blade and / or a vane position. The control system may also include control electronics for controlling one or more servomotors, in particular for controlling at least one of the aforementioned servomotors for adjusting / adjusting the blade / vane position. The control unit may e.g. be connected via a data line to the control electronics. This makes it possible for the servomotor or the servomotors to be controllable as a function of the flow velocity of the coolant.

Preferably, the cooling system comprises a capacitor, which is usefully also part of a working fluid circuit. Advantageously, the condenser can be flowed through by the thermal working medium. Furthermore, it is expedient if the condenser can be flowed through by the coolant. Coolant flow through the condenser can cause the condenser and / or the thermal working medium flowing through the condenser to be cooled via heat exchange with the coolant. In particular, can the condenser should be prepared to liquefy the thermal fluid.

It makes sense to connect the condenser to the coolant pump via a pipe system. If the cooling system comprises several coolant pumps, the condenser can be connected via the pipe system to one, to several or all of these coolant pumps. The thermal working fluid can be supplied after its cooling / liquefaction again the heat source. The capacitor thus allows a closed working fluid circuit. Conveniently, the cooling system comprises at least one motor for driving the coolant pump. Preferably, the engine is at least partially disposed above the coolant pump. The motor can also be arranged on a, in particular cantilevered, frame. Furthermore, a motor shaft of the motor can be aligned at least approximately axially parallel to the pump shaft. This allows a compact arrangement of engine and coolant pump.

The engine can be surrounded by a soundproof hood. A noise protection hood can be understood to mean a housing for reducing the noise emission of a machine, in particular an engine. The soundproof hood expediently has at least one door, which may be closed, e.g. for maintenance - allows access to the engine. The soundproof hood can serve for occupational safety and / or have the purpose of keeping environmental pollution low by reducing the noise emission.

Preferably, the coolant pump is drivable by means of a belt by the motor. The belt may serve to transmit torque between the pump shaft and the motor shaft. Advantages of the belt can be its great Life and / or low maintenance, especially in comparison with a gear transmission to be.

A first pulley may be attached to the pump shaft. A second pulley may be attached to the motor shaft. The belt can wrap around the first and / or second pulley in sections. Further, the belt may be tensioned by the first and / or the second pulley.

A torque transmission ratio in the transmission of the torque between the motor shaft and the pump shaft may be adjustable by a size ratio of the two pulleys. This allows a rotational speed of the engine to be different from a rotational speed of the coolant pump.

The cooling system may include a cooling tower. As a cooling tower, a plant can be conceived that is prepared to release waste heat from power plant processes to the environment. The cooling tower is preferably prepared to extract heat from the coolant, in particular the heat absorbed by the coolant as it flows through the condenser. In the cooling tower, heat exchange between the coolant introduced into the cooling tower and another medium, e.g. the cooling tower through the air.

Further, the cooling system may include a flow guide between the cooling tower and the coolant pump. A flow guide can be understood to mean an element or a system consisting of a plurality of elements ("flow guidance elements") for guiding / guiding the coolant A flow guidance element can be, inter alia, a pipe or a flow-through basin , in particular by a shape and / or an arrangement of the flow-guiding elements, can be predetermined. Advantageously, the flow guide is designed such that a coolant flow between the cooling tower and the coolant pump is deflected by the flow guide a maximum of two times. Because each redirection of the coolant flow can lead to friction-induced losses of kinetic

Lead energy of the coolant. In addition, a flow guide in which the coolant flow is deflected more than two times, may increase a vertical extent of the cooling system.

In particular, a change in direction of the coolant flow which occurs during a vertical inflow into a tank and a horizontal outflow from the tank can be regarded as a deflection.

Furthermore, the cooling system may comprise a flow guide between a coolant source and the coolant pump. Logically, this flow guide is prepared to direct the coolant from the coolant source to the coolant pump. In particular, if water is used as the coolant, the coolant source may be a body of water, e.g. a lake or a river, act.

Advantageously, the flow guide between the coolant source and the coolant pump is configured such that a coolant flow between the coolant source and the coolant pump is deflected by a maximum of twice through this flow guide. In an advantageous embodiment, the coolant pump has a largely tubular, in particular horizontally aligned pump housing. The pump housing can i.a. serve a liquid-tight and / or pressure-tight completion of the coolant pump.

The pump housing can surround the impeller arranged on the pump shaft, the tail of the coolant pump and / or at least in sections the pump shaft. In particular, that can Tail be firmly connected to the pump housing. Furthermore, the pump housing may be arranged coaxially with the pump shaft. It can thereby be achieved that the coolant pump can be flowed through horizontally by the coolant.

A cross-sectional area or diameter of the pump housing may be variable over a length of the pump housing. The pump housing may have a passage through which e.g. the belt be guided.

The coolant pump may have an inlet nozzle. The inlet nozzle may be a housing part of the pump housing. Conveniently, this housing part forms a coolant inlet end of the pump housing. Alternatively, the inlet nozzle may be a separate component fastened to the coolant inlet end of the pump housing. The inlet nozzle preferably has a decreasing in the flow direction of the coolant cross-sectional area. This allows acceleration of the coolant as it enters the pump housing. The acceleration of the coolant as it enters the pump housing may cause inhomogeneities in a spatial velocity distribution of the coolant flow to be minimized. Preferably, the pump shaft is partially surrounded by a sheath which shields parts of the pump shaft against contact with the coolant. This makes it possible that only the arranged on the pump shaft impeller, but not sheathed portions of the pump shaft, comes into contact with the coolant. Consequently, for a low-wear operation of the coolant pump under certain circumstances a - in view of contamination with foreign particles - lower coolant quality may be sufficient. According to a preferred embodiment, the cooling system comprises a coolant inlet chamber. The coolant inlet chamber may be a collecting space for the coolant, such as a basin. Conveniently, the coolant inlet chamber is present the coolant pump, in particular directly in front of the coolant pump, arranged - based on the flow direction of the coolant. By means of the coolant inlet chamber, a uniform and / or swirl-free inflow of the coolant into the coolant pump can be achieved. For a uniform and / or swirl-free inflow of the coolant into the coolant pump, a coolant level in the coolant inlet chamber preferably exceeds a highest point in the interior of the pump housing.

Turbulences in the coolant as it flows into the coolant pump cause the efficiency of the coolant pump to decrease and / or the coolant pump to be damaged, in particular if the turbulences draw air into the coolant.

Further, it is expedient if the pump housing is connected at its coolant inlet end with the coolant inlet chamber. The pump housing may be directly connected to the coolant inlet chamber. The pump housing can also be connected by a pipe with the coolant inlet chamber. It makes sense for the coolant inlet chamber to have a coolant outlet opening for admitting the coolant into the coolant pump.

The coolant inlet chamber may have a height which is at most 1.5 times greater than a maximum diameter, in particular an inner diameter, of the pump housing. Because of the horizontal alignment of the pump shaft, a low coolant level height may be sufficient to allow a smooth and / or vortex-free flow of the coolant into the coolant pump.

Preferably, the coolant pump is set up dry. Under a dry installation of the coolant pump can be understood that the pump housing only from the inside with the Coolant comes into contact. An advantage of the dry installation of the coolant pump is the good accessibility to the coolant pump, eg for maintenance work. Conveniently, the pump housing is connected at its coolant inlet end to the coolant outlet opening of the coolant inlet chamber such that a space in which the coolant pump is installed is sealed against ingress of coolant. Further, it is expedient if the pump housing is connected at its coolant outlet end with a pipe system, in particular the pipe system between the coolant pump and the condenser, that the space in which the coolant pump is placed, sealed against ingress of coolant.

Furthermore, the cooling system can have at least one propellant rake, in particular if water is used as the coolant and the water is taken from a body of water. The propellant rake can be a device which has the task of collecting objects driving in the coolant ("flotsam"), for example to protect plants / machines behind them from damage. especially in the inlet chamber, arranged.

The propellant rake preferably comprises a multiplicity of metal bars ("rake bars"), in particular arranged in parallel or lattice-like manner

movable cleaning machine for machine cleaning of the computing bars have.

The cooling system can also comprise a multi-stage propellant rake system with successively arranged propellant rakes. The multistage flotation system may include a coarse and a fine rake. A distance of the computing bars of the coarse crushing may be 80-100 mm, for example. A distance of the computing bars of the fine computing can be eg 10-40 mm. Furthermore, the cooling system may include a wire belt machine. The sieve belt machine may be a device with a sieve belt ("sieve belt") composed of a plurality of sieve-like elements, in particular for the purpose of filtering floats It makes sense to arrange the filter belt machine in front of the coolant pump - in relation to the flow direction of the coolant.

The description of advantageous embodiments given hitherto contains numerous features, which in the individual subclaims are reproduced in part in several groups. However, these features may conveniently be considered individually and summarized to meaningful further combinations. In particular, these features can be combined individually and in any suitable combination with the thermal power plant according to the invention.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the exemplary embodiment, which will be described in more detail in conjunction with the drawings. The embodiment is illustrative of the invention and does not limit the invention to the combination of features set forth therein, including functional features. In addition, suitable features may also be considered explicitly isolated and combined with any of the claims.

1 shows a schematic representation of a thermal power plant with a cooling system, which comprises a pump structure, 2 shows a schematic cross-sectional view of the pump structure of FIG. 1

1 shows a schematic representation of a thermal power plant 2. The thermal power plant 2 is a

Steam power plant, i. it uses water (steam) as a working fluid.

The thermal power station 2 comprises a steam generator 4 (Dampfkes- be), a steam turbine 6, a generator 8, a working fluid pump 10, a first pipe system 12 for guiding the working fluid and a cooling system 14th

The cooling system 14 comprises a cooling tower 16, a condenser 18, a pump building 20 and a second pipe system 22 for guiding a coolant. The pump structure 20 is arranged below the earth's surface. In the pump structure 20 u.a. a coolant pump for conveying the coolant and a motor for driving the coolant pump arranged. These and other arranged in the pump structure 20 elements of the cooling system 14 are not shown in FIG 1 for the sake of simplicity. A representation of the arranged in the pump structure 20 elements of the cooling system 14 can be found in FIG 2, which will be described below.

The working medium pump 10 conveys the working fluid in a liquid state through the first piping system 12 to the steam generator 4. In the steam generator 4, a fossil fuel, such as e.g. Natural gas, burned. This creates heat, which is partially absorbed by the work equipment. By absorbing a portion of the heat, the working fluid is transferred from the liquid state to a gaseous state (water vapor). The resulting during combustion of the fuel gases pass through an exhaust vent 26 from the steam generator 4.

From the steam generator 4, the gaseous working fluid flows through the first pipe system 12 to the steam turbine 6. The working fluid releases some of its previously absorbed heat as kinetic energy to the steam turbine 6, causing it to rotate. Via a turbine shaft 28 of the steam turbine 6, the generator 8 is driven, which converts the kineti- see energy from the rotation of the steam turbine 6 into electrical energy, which is fed via a power line 30 in a not shown in FIG 1 power grid.

From the steam turbine 6, the gaseous working fluid flows through the first pipe system 12 on to the condenser 18, which is prepared for cooling, in particular for liquefying, the working fluid. In the condenser, the working fluid is liquefied and gives its waste heat to the circulating in the cooling system 14 coolant. The coolant used is liquid water.

The liquefied working fluid is conveyed by the working fluid pump 10 through the first pipe system 12 again to the steam generator 4. The working fluid thus passes through a closed working fluid circuit with periodically occurring thermodynamic changes of state.

The coolant pump conveys the coolant through the second pipe system 22 to the condenser 18. In the condenser 18, the coolant absorbs the waste heat of the working fluid. From the condenser 18, the coolant is conveyed from the coolant pump through the second pipe system 22 to the cooling tower 16.

The cooling tower 16 of the cooling system 14 comprises a shell support 32 made of concrete, which is essentially a form of a

Having rotational hyperboloid and is open at its upper end. With its lower end, the shell structure 32 is placed on supports 33. Under the shell structure 32 and / or under the supports 33, a basin designated as cooling tower cup 34 is arranged.

By a Verrieselungsanlage 36, the coolant is sprayed into the cooling tower 16. Inside the cooling tower 16 finds a heat exchange between the air in the cooling tower 16 and the sprayed coolant instead, whereby the air is heated and rises. Some of the coolant drips directly into the cooling tower cup 34, but partially the coolant is guided upwards by the heated air. At above the scrubber 36 arranged Tropfenabscheidern 38 condenses a majority of the heated air with upwardly guided coolant first and then drips into the cooling tower cup 34th

The heated air exits the cooling tower 16 at the upper end of the cooling tower 16. Due to the escape of the heated air from the cooling tower 16 creates a suction effect, which is why

Distances between the supports 33 fresh air flows into the cooling tower 16.

The cooling system 14 comprises a first flow guide 40 arranged between the cooling tower 14 and the coolant pump, wherein a part of the first flow guide 40 is a component of the second pipe system 22 and a coolant inlet chamber arranged in the pump structure 20 forms another part of the first flow guide 40. From the cooling tower cup 34, the coolant flows through the first flow guide 40 to the coolant pump in the pump structure 20.

In order to reduce an increase in salinity in the coolant resulting from evaporation of a portion of the coolant in the cooling tower 16 and resulting in deposits in the cooling system 14, a portion of the remaining coolant is diverted into a flow via the second pipe system 22.

Furthermore, the cooling system 14 includes a second, between a coolant source 44 and the coolant pump disposed flow guide 42, wherein a part of the second flow guide 42 is a part of the second pipe system 22 and arranged in the pump structure 20 coolant inlet chamber forms another part of the second flow guide 42. The coolant source 44 in the present case is the same flow into which the coolant is discharged. In order to compensate for a loss of coolant resulting from the evaporation of coolant and the discharge of coolant into the flow, the pump structure 20 is supplied with additional coolant (water) from the coolant source 44 (the flow) by the second flow guide 42. From the pump structure 20, the coolant is conveyed by the coolant pump again to the condenser 18. The coolant thus passes through a circuit, this cycle is open in contrast to the circuit of the working fluid ("circulation cooling with cooling tower").

For a better traceability of FIG. 1, flow directions 46 of the working medium, flow directions 48 of the coolant and a flow direction 50 of the flow are shown in FIG. The direction of flow 50 of the flow shows upwards only according to the selected perspective, this is not intended to indicate that the river is flowing uphill.

2 shows a schematic, not to scale, cross-sectional view of the pump structure 20 from FIG. 1.

In the pump construction 20, the previously mentioned coolant pump 52 and the previously mentioned motor 54 for driving the coolant pump 52 are arranged. The coolant pump 52 in the present case is a horizontal Kaplan turbine.

The coolant pump 52 has a pump shaft 56 and the motor has a motor shaft 58. Both the pump shaft 56 and the motor shaft 58 are aligned horizontally. Thus, the motor shaft 58 and the pump shaft 56 are aligned parallel to each other. Furthermore, the coolant pump 52 has a largely tubular pump housing 60. The pump shaft 56 is supported by means of two shaft bearings 62, which are connected to the pump housing 60, in the pump housing 60, wherein the pump housing 60, the pump shaft 56 completely surrounds.

In addition, the pump housing 60 surrounds a arranged on the pump shaft 56, non-positively connected to the pump shaft 56 impeller 64 with a ring-shaped arranged spin fine 66. The impeller 64 is an axial. That the impeller 64 is prepared to axially convey the coolant 68. The rotor blades 66 of the impeller 64 are adjustable, in particular rotatable about an axis oriented substantially perpendicular to the pump shaft 56.

In addition, a tail unit 70 is arranged in the pump housing 60, which is arranged behind the rotor wheel 64, based on the flow direction of the coolant 68. The tail unit 70 comprises annularly arranged guide vanes 72. The stator vanes 72 are adjustable, in particular about one substantially axis aligned perpendicular to the pump shaft 56 rotatable, and connected to the pump housing 60.

By means of the tail 70, the swirl of the coolant 68 is reduced, while a static pressure of the

Coolant 68 is increased, whereby friction-induced losses of kinetic energy are reduced in a coolant flow. The vanes 72 are adjustable such that coolant flow through the coolant pump 52, e.g. for maintenance purposes, can be interrupted.

The coolant pump 52 includes a first actuator 74 for adjusting a vane position disposed on the pump housing 60. In addition, the coolant pump 52 comprises a second servo motor 76 for adjusting a running Vane position. The second servo motor 76 is disposed in the pump shaft 56, which is hollow from the inside.

The adjustment of the running blade position by the second servomotor 76 is effected in that the second servomotor 76 drives or linearly displaces an adjusting rod 78 arranged in the pump shaft 56, to which the rotor blades 66 are coupled. The adjustability of the vanes 72 and blades 66 allows an efficiency of the coolant pump 52 to be maximized under different operating conditions and to provide the coolant coverage required that is low. On the pump shaft 56, a control unit 80 for controlling a flow velocity of the coolant 68 is arranged. The control unit 80 is arranged behind the tail 70 - based on the flow direction of the coolant 68 - and comprises a flow sensor, not shown in FIG 2 for measuring the flow velocity of the coolant.

The control unit 80 is part of a control system 82 for automatically controlling the blade and vane position. The control system 82 further comprises an electronic control unit 84, which is connected to the control unit 80 via a data line. The control electronics 84 is prepared to convert an input signal transmitted by the control unit 80, which is dependent on the measured flow velocity of the coolant 68, into control signals which are output by the control electronics 84 via data lines to the two control motors. The two servomotors adjust the rotor blade -

/ Leitschaufelstellung depending on the transmitted to the Stellmo- tors control signals.

The coolant pump 52 has an inlet nozzle 86, which is a housing part of the pump housing 60 and has a coolant inlet. tread end of the pump housing 60 forms. The inlet nozzle 86 has a decreasing cross-sectional area in the flow direction 48 of the coolant 68 and thus enables an acceleration of the coolant 68 as it enters the pump housing 60.

The motor 54 for driving the coolant pump 52 is disposed on a frame 88 which is cantilevered. In addition, the motor 54 is arranged in sections, with the motor shaft 58, above the coolant pump 52.

The coolant pump 52 can be driven by the motor 54 by means of a belt 90. A first pulley 92 is fixed to the motor shaft 58, and a second pulley 94 is attached to the pump shaft 56. The belt 90 wraps around both the first pulley 92 and the second pulley 94 in sections and is stretched by the pulleys. A torque transmission ratio at a transmission of a torque between the motor shaft 58 and the pump shaft 56 is adjustable by a size ratio of the two pulleys.

The pump housing 60 has a passage 96 through which the belt 92 is guided. Through the implementation 96 and a data line which connects the control electronics 84 to the first servo motor 74, and a power supply line for the control electronics 84 and the second servo motor 76 are guided, said data line and the

Power supply line for the sake of clarity in Figure 2 are not shown.

Furthermore, the pump structure 20 includes the aforementioned coolant inlet chamber 98. The coolant inlet chamber 98 has a height 108 that is 1.5 times greater than a largest internal diameter 110 of the pump housing 60. The coolant inlet chamber 98 is arranged in front of the coolant pump 52, based on the flow direction 48 of the coolant 68. For introducing the coolant 68 into the coolant pump 52, the coolant inlet chamber 98 has a coolant outlet opening 100.

Due to the horizontal alignment of the pump shaft 56 and the adjustability of the vanes 72 and the blades 66 it is achieved that an installation height / depth of the coolant pump 52 with respect to a coolant level in the coolant inlet chamber 98 is low (low coolant coverage) - compared to an equal size Coolant pump with vertically aligned pump shaft and non-adjustable vanes / blades.

In the coolant inlet chamber 98, a Treibgutrechen 102 is arranged. The Treibgutrechen 102 has horizontally aligned rake bars, which, however, are not visible in the perspective shown.

In the present case, the coolant inlet chamber 98 forms a coolant supply 104, through which the coolant 68 flows into the coolant pump 52, in particular into the inlet nozzle 86 of the coolant pump 52. The coolant supply 104 is designed such that the coolant 68 flows (axially) into the coolant pump 52 parallel to the pump shaft 56.

A pipe of the second pipe system 22 forms a coolant outlet 106, through which the coolant 68 flows out of the coolant pump 52. The coolant outlet 106 is designed such that the coolant 68 flows out of the coolant pump 52 parallel to the pump shaft 56.

The coolant pump 52 is sealingly connected to the coolant supply 104 at its coolant inlet end, ie with the inlet nozzle 86, and is connected to its coolant outlet end in a sealed manner to the coolant outlet 106, so that the coolant pump 52 is set up in a dry state. In FIG 2, the portion of the first flow guide 40, which is a part of the second pipe system 22 and is guided through the pump structure 20, to see sections. In addition, in FIG. 2, the part of the second flow guide 42, which is a component of the second pipe system 22 and guided through the pump structure 22, can be seen in sections. The coolant inlet chamber 98 forms a common part of both flow guides. An initially horizontal coolant flow is first deflected vertically downwards by the respective flow guide. Through the coolant inlet chamber 98, the coolant flow is then deflected in such a way that the coolant 68 flows horizontally into the coolant pump 52.

Before the coolant 68 enters the coolant pump 52, it first flows through the Treibgutrechen 102, whereby

Flotsam from the coolant 68 is filtered. The coolant 68 enters axially into the coolant pump 52, flows through the coolant pump 52 axially and exits axially from the coolant pump 52. Subsequently, the coolant 68 flows via the second pipe system 22 to the condenser 18. The flow sensor of the control unit 80 measures the flow rate of the coolant 68. In order to adapt a coolant pressure and a flow rate of the coolant pump 52 to a current coolant demand of the thermal power plant 2, the control system 82 automatically controls the Blade / vane position as a function of the measured flow velocity.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed example, and other variations can be derived therefrom without departing from the scope of the invention.

Claims

claims 1. thermal power plant (2) with a cooling system (14) for cooling a thermal working medium, characterized in that the cooling system (14) comprises at least one coolant pump (52) for conveying a coolant (68) whose pump shaft (56) is oriented horizontally. 2. Thermal power plant (2) according to claim 1, characterized in that the cooling system (14) comprises a coolant supply (104) which is designed such that the coolant (68) flows into the coolant pump (52) substantially parallel to the pump shaft (56). 3. thermal power plant (2) according to claim 1 or 2, characterized in that the cooling system (14) comprises a coolant outlet (106) which is configured such that the coolant (68) flows out of the coolant pump (52) substantially parallel to the pump shaft (56). 4. thermal power plant (2) according to one of the preceding claims, characterized in that on the pump shaft (56) at least one impeller (64) is arranged, which in particular is an axial wheel and adjustable blades (66). 5. thermal power plant (2) according to one of the preceding claims, characterized in that the coolant pump (52) is a horizontal Kaplan turbine. 6. thermal power plant (2) according to one of the preceding claims, characterized in that the coolant pump (52) a Has tail unit (70) with adjustable vanes (72). 7. Thermal power plant (2) according to one of the preceding claims, characterized in that the coolant pump (52) is equipped with a control unit (80) for controlling a flow velocity of the coolant (68). 8. thermal power plant (2) according to one of the preceding claims, characterized in that the cooling system (14) via a pipe system (22) with the coolant pump (52) connected capacitor (18) which is prepared for cooling the thermal working fluid, in particular for liquefying the thermal working fluid. 9. thermal power plant (2) according to one of the preceding claims, characterized in that the cooling system (14) comprises at least one motor (54) for driving the coolant pump (52), which is arranged at least in sections above the coolant pump (52) and the motor shaft (58) aligned at least approximately axially parallel to the pump shaft (56) is. 10. thermal power plant (2) according to claim 9, characterized by at least one belt (90), by means of which the coolant pump (52) is driven by the motor (54) is drivable. 11. Thermal power plant (2) according to one of the preceding claims, characterized in that the cooling system (14) comprises a cooling tower (16) and a flow guide (40) between the cooling tower (16) and the coolant pump (52), wherein the flow guide (40) is configured such that a coolant flow between the cooling tower (16) and the coolant pump (52) by the flow guide (40) is deflected a maximum of two times. 12. Thermal power plant (2) according to one of the preceding claims, characterized in that the cooling system (14) comprises a flow guide (42) between a coolant source (44), in particular a body of water, and the coolant pump (52), wherein the flow guide (42) is configured such that a coolant flow between the Coolant source (44) and the coolant pump (52) by the flow guide (42) is deflected a maximum of two times. 13. Thermal power plant (2) according to one of the preceding claims, characterized in that the coolant pump (52) has a largely tubular, in particular horizontally aligned pump housing (60), which at the Pump shaft (56) arranged impeller (64), a tail (70) of the coolant pump (52) and at least partially surrounds the pump shaft (56). 14. thermal power plant (2) according to claim 13, characterized in that the cooling system (14) comprises a front of the coolant pump (52) arranged coolant inlet chamber (98) whose height (108) a maximum of 1.5 times of a largest inner diameter (110) of the pump housing (60) carries , 15. Thermal power plant (2) according to one of the preceding claims, characterized in that the coolant pump (52) is set up dry.