WATER TURBINE AND / OR WATER PUMP

Description

[0001] The invention relates to a water turbine and / or water pump according to the preamble of claim 1, with an electrical machine that can be operated as a motor and / or generator.

[0002] Such electrical machines often have a squirrel-cage rotor or a permanent magnet rotor that rotates in a magnetic field generated by field windings. The resulting power loss heats the rotor and cannot be adequately dissipated by airflow. This often limits the performance of such machines.

[0003] Turbines and water pumps that are completely submerged are also known in the state of the art. These also pose the problem of dissipating the rotor's heat.

[0004] When designing the rotor, it is often sufficient to construct it as a hollow cylinder. For example, in a permanent magnet machine, such a hollow cylinder carries several individual permanent magnets or a layer of permanently magnetic material. In a squirrel-cage machine, the rotor can also consist of a hollow cage rotor or be formed from a hollow cylinder made of a highly conductive material such as copper or aluminum.

[0005] DE 10 2006 043 946 A1 discloses a completely submerged turbine in which the rotor and stator windings are arranged in a housing and sealed against the ingress of the surrounding water. In this water turbine, cooling is achieved by the surrounding water. However, even here, the dissipation of the power loss is often not sufficiently ensured at higher power levels.

[0006] From WO 2018 / 046219 A1, a water turbine with a hollow rotor is known, the windings of which are equipped with cooling channels for a primary cooling liquid.

[0007] The present invention is therefore based on the object of providing a water turbine and / or water pump in which the aforementioned disadvantages are avoided and the cooling of the rotor is improved.

[0008] This object is achieved by a water turbine and / or water pump having the features of independent claim 1. Advantageous developments of the invention are specified in the subclaims.

[0009] The object is achieved in that in the electrical machine, which can be operated as a generator and / or electric motor, wherein a rotor is rotatably mounted within a winding arrangement and is hollow, a fixed heat sink is arranged within the rotor for the contactless dissipation of heat.

[0010] This advantageously allows for high performance of the electric machine with compact dimensions, as the rotor cavity, especially a cylindrical rotor or squirrel-cage rotor, has a large surface area for heat dissipation, while at the same time, the heat loss can be dissipated only over a short distance through radiant heat and air convection. Since this occurs without contact, no additional friction losses occur. A much greater cooling capacity can be achieved than if the heat could only be dissipated via a shaft and the rotor bearings.

[0011] The rotor is advantageously a permanent magnet excited rotor.

[0012] These can be designed to be particularly compact, which means that the dissipation of waste heat is limited to the size.

[0013] In a favorable embodiment, the heat sink is double-walled and is flowed through by a cooling liquid.

[0014] In water pumps or water turbines, the driving water is available and can be passed, possibly filtered, through the heat sink. The heat sink can have internal guide elements for the coolant, particularly a spiral helix structure. It is also conceivable to use a spiral tube as a heat sink. Furthermore, it is also conceivable to provide a separate cooling circuit in the heat sink, which dissipates the waste heat via a heat exchanger with the ambient water in a water turbine. In an electrical machine installed on land, the coolant can dissipate the waste heat to the ambient air via a heat exchanger in a known manner.

[0015] The water turbine and / or water pump can be arranged at an angle to the horizontal, in particular vertically.

[0016] In an advantageous embodiment, a housing of the water turbine and / or water pump is gas-tight and the shaft of the rotor unit is guided downwards out of the housing through a shaft opening, so that penetration of water into the housing is prevented by a gas volume compressed in the housing.

[0017] The described cooling of the rotor's waste heat is particularly advantageous for underwater turbines. In these cases, the waste heat can ultimately be dissipated into the surrounding propulsion water, achieving high power density without causing thermal problems within the casing. The heat sink advantageously provides a much greater waste heat dissipation capacity than would be possible via the turbine shaft and rotor bearings alone.

[0018] Further advantages and details of the invention are explained in more detail with reference to the embodiment shown in the schematic figures. Fig. 1 in a schematic section an overall view of a water turbine and Fig. 2 a partial section with an electrical machine of the Fig. 1 .

[0019] The Fig. 1 shows, in a schematic section, an overall view of a water turbine 1 with a rotor 2 designed as a hollow cylinder, which is connected to a turbine 5 in a rotor unit 3 via a shaft 4. The turbine 5 is supplied with drive water via guide vanes 6, which is discharged downwards, for example via a suction pipe not shown here.

[0020] The water turbine 1 has a gas-tight housing 7 which is open at the bottom so that the entry of water is prevented by compressed air or gas, even if the water turbine 1 is arranged completely under water.

[0021] The rotor 2 is surrounded by stator windings 8 and together with this forms an electrical machine 9, in the present example as a generator 10. However, it is also possible to operate such a water turbine 1 as a pump, in which the electrical machine 9 serves as the drive motor.

[0022] A heat sink 11 is inserted into the cavity of the rotor 2, which absorbs and dissipates the waste heat of the rotor 2 with a small gap via radiant heat as well as convection of the air contained in the housing 7.

[0023] The Fig. 2 shows a section with the electric machine 9 of the Fig. 1The rotor 2, arranged within the stator windings 8, is designed as a hollow cylinder. The heat sink 11 is arranged in the hollow space of the rotor 2. The heat sink is double-walled and a cooling fluid is passed through its interior, as indicated by the arrows, to dissipate the waste heat and, for example, to feed it to a recooler.

Claims

1. Water turbine and / or water pump comprising an electric machine, which can be operated as a generator (10) and / or an electric motor, wherein a rotor (2) is rotatably mounted within a winding arrangement (8), comprising a cooling body (11) for dissipating heat, wherein the rotor (2) is connected to a turbine (5) via a shaft (4) and forms a rotor unit (3) of the water turbine (1) and / or water pump, wherein the rotor (2) is hollow, characterized in that the cooling body (11) is stationary and is located within the rotor (2) for contactless dissipation of heat.

2. Water turbine and / or water pump according to Claim 1, characterized in that the rotor (2) is a permanent-magnet rotor.

3. Water turbine and / or water pump according to Claim 1 or 2, characterized in that the cooling body (11) is double-walled and has a cooling liquid flowing through it.

4. Water turbine and / or water pump according to one of the preceding claims, characterized in that the water turbine (1) and / or water pump is arranged at an angle with respect to the horizontal, in particular vertically.

5. Water turbine and / or water pump according to Claim 4, characterized in that a housing (7) of the water turbine (5) and / or water pump is gas-tight and the shaft (4) of the rotor unit (3) is routed downwards out of the housing (7) through a shaft opening, so that water is prevented from entering the housing (7) by a gas volume compressed in the housing.

6. Water turbine and / or water pump according to Claim 5, characterized in that the water turbine (1) and / or water pump is located under water.