CA3060605A1 - Split runner - Google Patents
Split runner Download PDFInfo
- Publication number
- CA3060605A1 CA3060605A1 CA3060605A CA3060605A CA3060605A1 CA 3060605 A1 CA3060605 A1 CA 3060605A1 CA 3060605 A CA3060605 A CA 3060605A CA 3060605 A CA3060605 A CA 3060605A CA 3060605 A1 CA3060605 A1 CA 3060605A1
- Authority
- CA
- Canada
- Prior art keywords
- runner
- parts
- rotational axis
- contact surfaces
- blades
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011248 coating agent Substances 0.000 claims description 10
- 238000000576 coating method Methods 0.000 claims description 10
- 238000005299 abrasion Methods 0.000 claims description 6
- 238000011144 upstream manufacturing Methods 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 13
- 230000009286 beneficial effect Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 230000008439 repair process Effects 0.000 description 4
- 239000004576 sand Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000003754 machining Methods 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000003801 milling Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000010285 flame spraying Methods 0.000 description 1
- 238000007749 high velocity oxygen fuel spraying Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/18—Rotors
- F04D29/22—Rotors specially for centrifugal pumps
- F04D29/2205—Conventional flow pattern
- F04D29/2222—Construction and assembly
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B3/00—Machines or engines of reaction type; Parts or details peculiar thereto
- F03B3/12—Blades; Blade-carrying rotors
- F03B3/125—Rotors for radial flow at high-pressure side and axial flow at low-pressure side, e.g. for Francis-type turbines
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
- B23P15/006—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass turbine wheels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
- B23P15/04—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass turbine or like blades from several pieces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B3/00—Machines or engines of reaction type; Parts or details peculiar thereto
- F03B3/12—Blades; Blade-carrying rotors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B3/00—Machines or engines of reaction type; Parts or details peculiar thereto
- F03B3/12—Blades; Blade-carrying rotors
- F03B3/128—Mounting, demounting
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/18—Rotors
- F04D29/22—Rotors specially for centrifugal pumps
- F04D29/2261—Rotors specially for centrifugal pumps with special measures
- F04D29/2294—Rotors specially for centrifugal pumps with special measures for protection, e.g. against abrasion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/26—Rotors specially for elastic fluids
- F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
- F04D29/284—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for compressors
- F04D29/285—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for compressors the compressor wheel comprising a pair of rotatable bladed hub portions axially aligned and clamped together
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2230/00—Manufacture
- F05B2230/20—Manufacture essentially without removing material
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2230/00—Manufacture
- F05B2230/90—Coating; Surface treatment
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2260/00—Function
- F05D2260/30—Retaining components in desired mutual position
- F05D2260/37—Retaining components in desired mutual position by a press fit connection
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Hydraulic Turbines (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention relates to a runner (1) for a hydraulic turbine, pump or pump turbine, in particular for a Francis turbine, which runner (1) can be mounted such that it can be rotated about a rotational axis (10) and has runner blades (4) which are arranged around the rotational axis (10) along a circumferential direction, wherein the runner (1) has at least two runner parts which are connected to one another via contact surfaces (9). In order to achieve a simple manufacturing capability, it is provided according to the invention that the contact surfaces (9) are positioned and oriented in such a way that a moment can be transmitted about the rotational axis (10) between the runner parts substantially via forces tangentially with respect to the contact surfaces (9).
Description
SPLIT RUNNER
The invention relates to a runner for a hydraulic turbine, pump or pump turbine, in particular for a Francis turbine, which can be mounted so that it can rotate around a rotational axis, and has runner blades arranged around a rotational axis along a circumferential direction, wherein the runner has at least two runner parts that are detachably connected with each other via contact surfaces.
Various runners of the kind mentioned at the outset have become known in prior art. Such runners are used in particular for Francis turbines, for example to derive electrical energy from hydropower or to pump liquids, and as a general rule are fabricated as integral castings, welded structures or forged components. In order to minimize wear on such runners, it is beneficial for the runners to be coated with a wear-reducing coating. However, such a coating can most often not be applied completely on small and medium-sized runners, because a runner blade channel between the spatially strongly curved runner blades can frequently not be accessed in its entirety.
It became known from document DE 10 2015 219 331 Al to give the runner a split design to obtain more easily accessible blade parts. However, manufacturing a runner disclosed in this document is associated with a high outlay, so that small and medium-sized runners in prior art can only be manufactured at a high cost or with no resistance to wear.
This is where the invention comes in. The object of the invention is to indicate a runner of the kind mentioned at the outset, which can be easily provided with a coating, while at the same time being easy and thus cost-effective to manufacture.
This object is achieved according to the invention by a runner of the kind mentioned at the outset, in which the contact surfaces are positioned and oriented in such a way that a moment can be transmitted around the rotational axis between the runner parts essentially via forces tangential to the contact surfaces.
It was recognized within the framework of the invention that a simple manufacturing capability for a runner, in which in particular the runner blade channel between the runner blades can be easily coated over the entire surface, is achieved if the contact surfaces of the individual runner parts are positioned and oriented in such a way that a moment can be transmitted around the rotational axis between the runner parts essentially via forces tangential to the contact surfaces. Such contact surfaces can be easily fabricated, and both manufactured and machined with a high precision, for example through turning or milling. This significantly reduces any complexity in manufacture by comparison to split runners in prior art.
In order to transmit a moment around the rotational axis essentially via forces tangential the contact surfaces, the contact surfaces can be designed as rotational surfaces around the rotational axis, for example as conical surfaces, cylindrical surfaces or surfaces perpendicular to the rotational axis. Such surfaces can be easily manufactured. It goes without saying that such a rotationally symmetrical contact surface does not absolutely have to include the rotational axis, even though this is preferred.
There are basically a variety of ways to connect the runner parts via the contact surfaces so as to transmit a moment around the rotational axis tangential to the contact surface, for example through adhesion. The runner parts are preferably detachably connected via the contact surfaces, so as to enable an easy repair or replacement of a runner part.
It has proven effective for the individual runner parts to be essentially non-positively connected. A
torque is then transmitted between the runner parts essentially in a non-positive and frictional manner.
It is advantageous that the individual runner parts only be connected non-positively. A frictional connection prevents contact corrosion as well as fretting or local fusing and tearing, which would take place given a positive force transmission. In addition, connecting elements that connect the runner parts, for example screws, are then exposed to essentially only a quasi-static load during operation, thereby minimizing any mechanical load on the latter and ensuring a high level of security against material fatigue.
In order to ensure a desired coefficient of friction on the contact surfaces despite a medium that usually surrounds the runner during operation, as a rule water, the contact surfaces can be sealed, for example by 0-rings between the runner parts.
In order to transmit a high moment, it is advantageous that the runner parts be indirectly connected, in particular via one or several films that increase the coefficient of friction.
Even given a low normal force or a smaller load placed on connecting screws, this makes it possible to ensure that a high moment is transmitted.
In order to achieve an especially simple manufacturing capability, it is beneficial that all contact surfaces be roughly parallel. The individual, usually planar contact surfaces can here lie in a plane or in planes spaced apart from each other. This makes it especially easier to rework the contact surfaces, for example during an inspection of the runner, since a contact surface that has been undulatingly or conically deformed through exposure to heat, for example, can be easily refurbished, for example by turning. Machining in a tenth of a millimeter range is often sufficient for eliminating the deformation.
This type of machining essentially has no effect on the hydraulic properties of the runner, so that a contact surface can be easily refurbished, without detracting from the function of the runner.
It is advantageous that all contact surfaces be roughly perpendicular to the rotational axis. A contact surface can then be subsequently machined especially easily, with only minimal or no effects on the hydraulic function of the runner.
In order to achieve an especially simple manufacturing capability, it preferably provided that the contact surfaces on a runner part be formed by only two planar and parallel surfaces on the rim and hub of the runner part, which are perpendicular to the rotational axis. A runner part can here also be designed as a hydraulically independently acting runner.
The runner parts can basically comprise any parts of the runner. However, an especially simple manufacturing capability for a completely coatable runner is achieved if each runner part has a portion of each runner blade. All runner blades are then configured in such a way as to be readily accessible and easily coatable. Looping and a length of the individual runner blades are here reduced, thus resulting in a better access to the runner blade channel, so that the runner blade channels between the runner blades can be especially easily coated even given very small runners. In this conjunction, it is especially beneficial that all runner blades of a runner part essentially be identical, so as to minimize complexity in the manufacturing process. If the individual runner parts are designed as hydraulically independently acting runners, each runner blade of each runner part has its own leading edge and its own trailing edge.
, .
It is advantageously provided that each runner part envelop the rotational axis. As a consequence, the runner is axially split into several runner parts, which results in a uniform stress distribution in the individual runner parts.
As a rule, the runner is split into several runner parts along the rotational axis, wherein the size of the individual runner parts or a position of dividing planes are usually selected in such a way as to form contact surfaces perpendicular to the rotational axis on a rim and on a hub of the runner. A runner part can here also be designed as an independent runner, so that the runner is composed of several independent runners. In addition, the size of the individual runner parts or runners and a position of one or several dividing planes is usually selected in such a way as to optimize accessibility to the areas, so that a coating can be applied and repairs can be easily effected, for example on damages caused by abrasion, in particular welding or grinding operations.
It has been found beneficial for each runner part to have a portion of a rim of the runner. It has further proven advantageous for each runner part to have a portion of the hub of the runner. As a consequence, the runner is axially split into several runner blade rings, which each can operate as hydraulically independent runners. For example, splitting the runner into two runner parts yields a division into a runner part that comprises a high-pressure runner blade ring, and a runner part that comprises a low-pressure runner blade ring, wherein the low-pressure runner blade ring is downstream from the high-pressure runner blade ring in the direction of flow when using the runner for a turbine, thereby providing a serial connection of the runner blade rings. It goes without saying that the high-pressure runner ring is downstream from the low-pressure runner blade ring in the direction of flow when using the runner for a pump. The individual runner blade rings are here configured in such a way that the serial connection yields a required hydraulic characteristic. To this end, it can be provided that the leading and trailing edges of the individual runner blade rings be correspondingly profiled in design.
As a consequence, the runner according to the invention can be designed as a sequential connection of two or more independent runners or runner blade rings, which each have runner blades with separate leading and trailing edges, which are offset, but mechanically rigidly connected. In the case of a runner according to the invention, the runner blades of the individual runner parts can therefore be equivalent to other runner blades or runner blades of an independent runner. By contrast, split runners in prior art only have split runner blades, which are tightly connected without any offset via contact surfaces, so that runners in prior art do not produce any additional leading and trailing edges between the runner parts, as opposed to the runner according to the invention.
It can further be provided that the individual runner blade rings or runner parts be spaced apart from each other in one region of the runner blades in the assembled state, so as to achieve an optimal efficiency. A contact surface between the runner parts on the runner blades is here also omitted, resulting in a reduced complexity in the manufacturing process.
In addition, the runner blade rings can also be twisted relative to each other, so as to maximize efficiency. A distance between the runner blades required for maximizing efficiency as well as a twisting angle between the runner blade rings or runner parts can here be determined during tests and/or through calculation, for example in simulations.
The runner is then usually configured in such a way that a hydraulic moment and an axial thrust are transmitted by one or several low-pressure runner blade rings to the high-pressure runner blade ring, from which the moments and forces are transmitted to a shaft, for example which can be connected with a generator. The shaft is usually connected with the hub of the runner.
In order to be able to easily effect repairs, it is beneficial for the individual runner parts to be connected by screw joints with a hub of the runner and/or a rim of the runner. In this way, the runner parts can be easily detached from each other.
In order to minimize wear on the runner, it is beneficial for the runner blades of the runner parts to be spaced apart from each other and arranged in such a way in an assembled state that, during use as intended, an outflow of an upstream runner part leads into a runner blade channel of a downstream runner part, and the outflow of the upstream runner part essentially does not impact a leading edge of the downstream runner part. In particular when using the runner in liquids with a high content of solids, for example water with a high percentage of sand, this easily minimizes wear to a leading edge of downstream runner parts or a low-pressure runner blade ring. The leading edge is here understood as an edge of the runner blade of the downstream runner part.
. .
In order to achieve a long service life, it is beneficial for the runner blades to have a coating that protects against abrasion. Coating usually takes place via high-speed flame spraying or in a so-called HVOF
spraying process. Naturally, the coating can also be fabricated using another method.
Additional features, advantages and effects of the invention may be gleaned from the exemplary embodiment described below. The drawings here being referenced show:
Fig. 1 an exploded view of a runner according to the invention;
Fig. 2 a runner according to the invention;
Fig. 3 and 4 sections through a runner according to the invention.
Fig. 1 and 2 show an isometric view of a runner 1 according to the invention, wherein Fig. 1 shows the runner 1 in an exploded view, so that individual runner parts are visible. As depicted, the runner 1 has several runner blades 4 arranged along a circumferential direction around the rotational axis 10, as well as a rim 7 and a hub 5. The runner 1 shown is split into two runner parts, wherein each runner part has a portion of each runner blade 4 along with a portion of the hub 6 and a portion of the rim 7. Contact surfaces 9 between the runner parts are parallel, and here oriented perpendicular to the rotational axis 10. In the runner 1 shown, the runner blades 4 of the individual runner parts are spaced apart, thereby yielding only two rotationally symmetrical contact surfaces 9 per runner part, which envelop the rotational axis 10 and are arranged on the rim 7 and hub 6 of the individual runner parts. As a consequence, no contact surfaces 9 are provided on the runner blades, so as to achieve a simple manufacturing capability simultaneously accompanied by an optimal efficiency.
In an alternative embodiment, however, contact surfaces 9 can also be provided on the runner blades 4.
The runner 1 is thus split into a runner part that comprises a high-pressure runner blade ring 2, and a runner part comprising a low-pressure runner blade ring 3, which each form hydraulically independent runners and are detachably and rigidly connected via the contact surfaces.
In the assembled state, the runner parts are connected via connecting screws 8, wherein the connection is usually configured in such a way that a hydraulic moment around the rotational axis 10 is transmitted from the low-pressure runner blade ring 3 to the high-pressure runner blade ring 2 via a frictional connection provided on the contact surfaces 9. An axial thrust is also transmitted via the contact surfaces 9. It goes without saying that forces in the direction of the rotational axis 10 are here also transmitted positively. The forces and moments are transmitted from the high-pressure runner blade ring 2 to a shaft, which can be connected with a generator or a motor, for example, depending on a use of the runner 1. As a consequence, a moment around the rotational axis 10 is transmitted between the contact surfaces 9 via forces tangential to the contact surfaces 9, normally through friction.
As evident, the runner blades 4 are usually strongly bent, as in Francis turbines. Splitting the runner blades 4 into here a respective two parts enables a complete coating of the runner blades 4, so that abrasion-induced wear can be reduced.
Fig. 3 and 4 show sections through a runner 1 according to the invention, in which the individual runner parts are connected via connection screws 8. As evident, a connection is established both on the hub 6 and on a rim 7 of the runner 1. As further evident, there is no direct connection between the runner blades 4. Forces and moments are thus transmitted exclusively via the contact surfaces 9 on the hub 6 and rim 7. The high-pressure runner blade ring 2 and the low-pressure runner blade ring 3 are further twisted relative to each other in such a way that an outflow of the high-pressure runner blade ring 2 leads into a channel of the low-pressure runner blade ring 3, thereby protecting a leading edge of the low-pressure runner blade ring 3 against wear caused by arising solids in a liquid with which the runner 1 is used, for example water with a sand content.
The connecting screws 8 are usually also protected against abrasion and corrosion, for example by a cover or a labyrinth seal.
A runner 1 according to the invention enables a complete coating of a runner blade channel 5 even given small and medium-sized runners, because the runner blade channel 5 is split, and thus readily accessible. In addition, splitting the runner 1 into several runner parts provides an improved machineability in the runner blade channels, thereby making it easy to perform machining operations in the runner blade channels of the individual runner parts, such as milling, welding or grinding. At the same time, the inventive configuration of the runner 1 makes it easy to manufacture and repair, because the contact surfaces 9 required for connecting the runner parts can be easily machined with a high precision.
. .
In the exemplary embodiment shown, the runner 1 is formed on two runner parts with runner blades 4 that are spaced apart and twisted relative to each other. It goes without saying that a runner 1 according to the invention can also be split into more than two runner parts or runner blade rings, and that the individual runner blades 4 of the runner parts need not necessary be spaced apart and/or twisted relative to each other.
In particular in Francis and pump runners in systems with a high content of sand in the water, the runner 1 according to the invention can be used to significantly minimize abrasion, while simultaneously ensuring a simple manufacturing capability. The invention thus provides an easily and cost-effectively manufacturable runner 1, which can be used to considerably reduce the operational risk to a power plant operator, even during use in liquids with a high sand content.
The invention relates to a runner for a hydraulic turbine, pump or pump turbine, in particular for a Francis turbine, which can be mounted so that it can rotate around a rotational axis, and has runner blades arranged around a rotational axis along a circumferential direction, wherein the runner has at least two runner parts that are detachably connected with each other via contact surfaces.
Various runners of the kind mentioned at the outset have become known in prior art. Such runners are used in particular for Francis turbines, for example to derive electrical energy from hydropower or to pump liquids, and as a general rule are fabricated as integral castings, welded structures or forged components. In order to minimize wear on such runners, it is beneficial for the runners to be coated with a wear-reducing coating. However, such a coating can most often not be applied completely on small and medium-sized runners, because a runner blade channel between the spatially strongly curved runner blades can frequently not be accessed in its entirety.
It became known from document DE 10 2015 219 331 Al to give the runner a split design to obtain more easily accessible blade parts. However, manufacturing a runner disclosed in this document is associated with a high outlay, so that small and medium-sized runners in prior art can only be manufactured at a high cost or with no resistance to wear.
This is where the invention comes in. The object of the invention is to indicate a runner of the kind mentioned at the outset, which can be easily provided with a coating, while at the same time being easy and thus cost-effective to manufacture.
This object is achieved according to the invention by a runner of the kind mentioned at the outset, in which the contact surfaces are positioned and oriented in such a way that a moment can be transmitted around the rotational axis between the runner parts essentially via forces tangential to the contact surfaces.
It was recognized within the framework of the invention that a simple manufacturing capability for a runner, in which in particular the runner blade channel between the runner blades can be easily coated over the entire surface, is achieved if the contact surfaces of the individual runner parts are positioned and oriented in such a way that a moment can be transmitted around the rotational axis between the runner parts essentially via forces tangential to the contact surfaces. Such contact surfaces can be easily fabricated, and both manufactured and machined with a high precision, for example through turning or milling. This significantly reduces any complexity in manufacture by comparison to split runners in prior art.
In order to transmit a moment around the rotational axis essentially via forces tangential the contact surfaces, the contact surfaces can be designed as rotational surfaces around the rotational axis, for example as conical surfaces, cylindrical surfaces or surfaces perpendicular to the rotational axis. Such surfaces can be easily manufactured. It goes without saying that such a rotationally symmetrical contact surface does not absolutely have to include the rotational axis, even though this is preferred.
There are basically a variety of ways to connect the runner parts via the contact surfaces so as to transmit a moment around the rotational axis tangential to the contact surface, for example through adhesion. The runner parts are preferably detachably connected via the contact surfaces, so as to enable an easy repair or replacement of a runner part.
It has proven effective for the individual runner parts to be essentially non-positively connected. A
torque is then transmitted between the runner parts essentially in a non-positive and frictional manner.
It is advantageous that the individual runner parts only be connected non-positively. A frictional connection prevents contact corrosion as well as fretting or local fusing and tearing, which would take place given a positive force transmission. In addition, connecting elements that connect the runner parts, for example screws, are then exposed to essentially only a quasi-static load during operation, thereby minimizing any mechanical load on the latter and ensuring a high level of security against material fatigue.
In order to ensure a desired coefficient of friction on the contact surfaces despite a medium that usually surrounds the runner during operation, as a rule water, the contact surfaces can be sealed, for example by 0-rings between the runner parts.
In order to transmit a high moment, it is advantageous that the runner parts be indirectly connected, in particular via one or several films that increase the coefficient of friction.
Even given a low normal force or a smaller load placed on connecting screws, this makes it possible to ensure that a high moment is transmitted.
In order to achieve an especially simple manufacturing capability, it is beneficial that all contact surfaces be roughly parallel. The individual, usually planar contact surfaces can here lie in a plane or in planes spaced apart from each other. This makes it especially easier to rework the contact surfaces, for example during an inspection of the runner, since a contact surface that has been undulatingly or conically deformed through exposure to heat, for example, can be easily refurbished, for example by turning. Machining in a tenth of a millimeter range is often sufficient for eliminating the deformation.
This type of machining essentially has no effect on the hydraulic properties of the runner, so that a contact surface can be easily refurbished, without detracting from the function of the runner.
It is advantageous that all contact surfaces be roughly perpendicular to the rotational axis. A contact surface can then be subsequently machined especially easily, with only minimal or no effects on the hydraulic function of the runner.
In order to achieve an especially simple manufacturing capability, it preferably provided that the contact surfaces on a runner part be formed by only two planar and parallel surfaces on the rim and hub of the runner part, which are perpendicular to the rotational axis. A runner part can here also be designed as a hydraulically independently acting runner.
The runner parts can basically comprise any parts of the runner. However, an especially simple manufacturing capability for a completely coatable runner is achieved if each runner part has a portion of each runner blade. All runner blades are then configured in such a way as to be readily accessible and easily coatable. Looping and a length of the individual runner blades are here reduced, thus resulting in a better access to the runner blade channel, so that the runner blade channels between the runner blades can be especially easily coated even given very small runners. In this conjunction, it is especially beneficial that all runner blades of a runner part essentially be identical, so as to minimize complexity in the manufacturing process. If the individual runner parts are designed as hydraulically independently acting runners, each runner blade of each runner part has its own leading edge and its own trailing edge.
, .
It is advantageously provided that each runner part envelop the rotational axis. As a consequence, the runner is axially split into several runner parts, which results in a uniform stress distribution in the individual runner parts.
As a rule, the runner is split into several runner parts along the rotational axis, wherein the size of the individual runner parts or a position of dividing planes are usually selected in such a way as to form contact surfaces perpendicular to the rotational axis on a rim and on a hub of the runner. A runner part can here also be designed as an independent runner, so that the runner is composed of several independent runners. In addition, the size of the individual runner parts or runners and a position of one or several dividing planes is usually selected in such a way as to optimize accessibility to the areas, so that a coating can be applied and repairs can be easily effected, for example on damages caused by abrasion, in particular welding or grinding operations.
It has been found beneficial for each runner part to have a portion of a rim of the runner. It has further proven advantageous for each runner part to have a portion of the hub of the runner. As a consequence, the runner is axially split into several runner blade rings, which each can operate as hydraulically independent runners. For example, splitting the runner into two runner parts yields a division into a runner part that comprises a high-pressure runner blade ring, and a runner part that comprises a low-pressure runner blade ring, wherein the low-pressure runner blade ring is downstream from the high-pressure runner blade ring in the direction of flow when using the runner for a turbine, thereby providing a serial connection of the runner blade rings. It goes without saying that the high-pressure runner ring is downstream from the low-pressure runner blade ring in the direction of flow when using the runner for a pump. The individual runner blade rings are here configured in such a way that the serial connection yields a required hydraulic characteristic. To this end, it can be provided that the leading and trailing edges of the individual runner blade rings be correspondingly profiled in design.
As a consequence, the runner according to the invention can be designed as a sequential connection of two or more independent runners or runner blade rings, which each have runner blades with separate leading and trailing edges, which are offset, but mechanically rigidly connected. In the case of a runner according to the invention, the runner blades of the individual runner parts can therefore be equivalent to other runner blades or runner blades of an independent runner. By contrast, split runners in prior art only have split runner blades, which are tightly connected without any offset via contact surfaces, so that runners in prior art do not produce any additional leading and trailing edges between the runner parts, as opposed to the runner according to the invention.
It can further be provided that the individual runner blade rings or runner parts be spaced apart from each other in one region of the runner blades in the assembled state, so as to achieve an optimal efficiency. A contact surface between the runner parts on the runner blades is here also omitted, resulting in a reduced complexity in the manufacturing process.
In addition, the runner blade rings can also be twisted relative to each other, so as to maximize efficiency. A distance between the runner blades required for maximizing efficiency as well as a twisting angle between the runner blade rings or runner parts can here be determined during tests and/or through calculation, for example in simulations.
The runner is then usually configured in such a way that a hydraulic moment and an axial thrust are transmitted by one or several low-pressure runner blade rings to the high-pressure runner blade ring, from which the moments and forces are transmitted to a shaft, for example which can be connected with a generator. The shaft is usually connected with the hub of the runner.
In order to be able to easily effect repairs, it is beneficial for the individual runner parts to be connected by screw joints with a hub of the runner and/or a rim of the runner. In this way, the runner parts can be easily detached from each other.
In order to minimize wear on the runner, it is beneficial for the runner blades of the runner parts to be spaced apart from each other and arranged in such a way in an assembled state that, during use as intended, an outflow of an upstream runner part leads into a runner blade channel of a downstream runner part, and the outflow of the upstream runner part essentially does not impact a leading edge of the downstream runner part. In particular when using the runner in liquids with a high content of solids, for example water with a high percentage of sand, this easily minimizes wear to a leading edge of downstream runner parts or a low-pressure runner blade ring. The leading edge is here understood as an edge of the runner blade of the downstream runner part.
. .
In order to achieve a long service life, it is beneficial for the runner blades to have a coating that protects against abrasion. Coating usually takes place via high-speed flame spraying or in a so-called HVOF
spraying process. Naturally, the coating can also be fabricated using another method.
Additional features, advantages and effects of the invention may be gleaned from the exemplary embodiment described below. The drawings here being referenced show:
Fig. 1 an exploded view of a runner according to the invention;
Fig. 2 a runner according to the invention;
Fig. 3 and 4 sections through a runner according to the invention.
Fig. 1 and 2 show an isometric view of a runner 1 according to the invention, wherein Fig. 1 shows the runner 1 in an exploded view, so that individual runner parts are visible. As depicted, the runner 1 has several runner blades 4 arranged along a circumferential direction around the rotational axis 10, as well as a rim 7 and a hub 5. The runner 1 shown is split into two runner parts, wherein each runner part has a portion of each runner blade 4 along with a portion of the hub 6 and a portion of the rim 7. Contact surfaces 9 between the runner parts are parallel, and here oriented perpendicular to the rotational axis 10. In the runner 1 shown, the runner blades 4 of the individual runner parts are spaced apart, thereby yielding only two rotationally symmetrical contact surfaces 9 per runner part, which envelop the rotational axis 10 and are arranged on the rim 7 and hub 6 of the individual runner parts. As a consequence, no contact surfaces 9 are provided on the runner blades, so as to achieve a simple manufacturing capability simultaneously accompanied by an optimal efficiency.
In an alternative embodiment, however, contact surfaces 9 can also be provided on the runner blades 4.
The runner 1 is thus split into a runner part that comprises a high-pressure runner blade ring 2, and a runner part comprising a low-pressure runner blade ring 3, which each form hydraulically independent runners and are detachably and rigidly connected via the contact surfaces.
In the assembled state, the runner parts are connected via connecting screws 8, wherein the connection is usually configured in such a way that a hydraulic moment around the rotational axis 10 is transmitted from the low-pressure runner blade ring 3 to the high-pressure runner blade ring 2 via a frictional connection provided on the contact surfaces 9. An axial thrust is also transmitted via the contact surfaces 9. It goes without saying that forces in the direction of the rotational axis 10 are here also transmitted positively. The forces and moments are transmitted from the high-pressure runner blade ring 2 to a shaft, which can be connected with a generator or a motor, for example, depending on a use of the runner 1. As a consequence, a moment around the rotational axis 10 is transmitted between the contact surfaces 9 via forces tangential to the contact surfaces 9, normally through friction.
As evident, the runner blades 4 are usually strongly bent, as in Francis turbines. Splitting the runner blades 4 into here a respective two parts enables a complete coating of the runner blades 4, so that abrasion-induced wear can be reduced.
Fig. 3 and 4 show sections through a runner 1 according to the invention, in which the individual runner parts are connected via connection screws 8. As evident, a connection is established both on the hub 6 and on a rim 7 of the runner 1. As further evident, there is no direct connection between the runner blades 4. Forces and moments are thus transmitted exclusively via the contact surfaces 9 on the hub 6 and rim 7. The high-pressure runner blade ring 2 and the low-pressure runner blade ring 3 are further twisted relative to each other in such a way that an outflow of the high-pressure runner blade ring 2 leads into a channel of the low-pressure runner blade ring 3, thereby protecting a leading edge of the low-pressure runner blade ring 3 against wear caused by arising solids in a liquid with which the runner 1 is used, for example water with a sand content.
The connecting screws 8 are usually also protected against abrasion and corrosion, for example by a cover or a labyrinth seal.
A runner 1 according to the invention enables a complete coating of a runner blade channel 5 even given small and medium-sized runners, because the runner blade channel 5 is split, and thus readily accessible. In addition, splitting the runner 1 into several runner parts provides an improved machineability in the runner blade channels, thereby making it easy to perform machining operations in the runner blade channels of the individual runner parts, such as milling, welding or grinding. At the same time, the inventive configuration of the runner 1 makes it easy to manufacture and repair, because the contact surfaces 9 required for connecting the runner parts can be easily machined with a high precision.
. .
In the exemplary embodiment shown, the runner 1 is formed on two runner parts with runner blades 4 that are spaced apart and twisted relative to each other. It goes without saying that a runner 1 according to the invention can also be split into more than two runner parts or runner blade rings, and that the individual runner blades 4 of the runner parts need not necessary be spaced apart and/or twisted relative to each other.
In particular in Francis and pump runners in systems with a high content of sand in the water, the runner 1 according to the invention can be used to significantly minimize abrasion, while simultaneously ensuring a simple manufacturing capability. The invention thus provides an easily and cost-effectively manufacturable runner 1, which can be used to considerably reduce the operational risk to a power plant operator, even during use in liquids with a high sand content.
Claims (5)
1. A runner (1) for a hydraulic turbine, pump or pump turbine, in particular for a Francis turbine, which can be mounted so that it can rotate around a rotational axis (10), and has runner blades (4) arranged around a rotational axis (10) along a circumferential direction, wherein the runner (1) has at least two runner parts that are connected with each other via contact surfaces (9), wherein the contact surfaces (9) are oriented perpendicular to the rotational axis (10), so that a moment can be transmitted around the rotational axis (10) between the runner parts essentially via forces tangential to the contact surfaces (9), characterized in that each runner part has a portion of each runner blade (4), a portion of a rim (7) and a portion of the hub (6) of the runner (1), wherein the individual runner parts are connected by a screw joint with the hub (6) of and the rim (7) of the runner, and spaced apart from each other in one region of the runner blades (4).
2. The runner (1) according to claim 1, characterized in that the runner parts are indirectly connected via one or several films that increase the coefficient of friction.
3. The runner (1) according to claim 1 or 2, characterized in that each runner envelops the rotational axis (10).
4. The runner (1) according to one of claims 1 to 3, characterized in that the runner blades (4) of the runner parts are arranged in such a way in an assembled state that, during use as intended, an outflow of an upstream runner part leads into a runner blade channel (5) of a downstream runner part, and the outflow of the upstream runner part essentially does not impact a leading edge of the downstream runner part.
5. The runner (1) according to one of claims 1 to 4, characterized in that the runner blades (4) have a coating that protects against abrasion.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ATA50629/2017A AT520226B1 (en) | 2017-07-28 | 2017-07-28 | Wheel |
| ATA50629/2017 | 2017-07-28 | ||
| PCT/AT2018/060116 WO2019018866A1 (en) | 2017-07-28 | 2018-06-07 | Split runner |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA3060605A1 true CA3060605A1 (en) | 2019-10-21 |
Family
ID=62705337
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3060605A Pending CA3060605A1 (en) | 2017-07-28 | 2018-06-07 | Split runner |
Country Status (6)
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| EP (1) | EP3658779B1 (en) |
| CN (1) | CN110914552B (en) |
| AT (1) | AT520226B1 (en) |
| CA (1) | CA3060605A1 (en) |
| CL (1) | CL2019003448A1 (en) |
| WO (1) | WO2019018866A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112247492B (en) * | 2020-10-26 | 2022-08-12 | 航天科工哈尔滨风华有限公司 | Method for connecting impeller cover of closed impeller and impeller |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH233642A (en) * | 1942-02-21 | 1944-08-15 | Buechi Alfred | Impeller for centrifugal fans or pumps. |
| US2710580A (en) * | 1946-10-29 | 1955-06-14 | Kellogg M W Co | Vaned rotor |
| AT224578B (en) * | 1959-09-21 | 1962-11-26 | Boehler & Co Ag Geb | Impeller for water turbines and pumps |
| DE1173038B (en) * | 1959-09-22 | 1964-06-25 | Charmilles Sa Ateliers | Impeller for Francis turbines with two interlocking and screwed-together blade ring parts |
| DE1428185A1 (en) * | 1963-12-21 | 1968-11-28 | Maschf Augsburg Nuernberg Ag | Impeller for centrifugal compressor with auxiliary rotor |
| DE19803390C1 (en) * | 1998-01-29 | 1999-02-11 | Voith Hydro Gmbh & Co Kg | Rotor wheel for Francis water turbine |
| US6318964B1 (en) * | 2000-09-08 | 2001-11-20 | Sheng Shyan Yang | Complex cooling fan with increased cooling capacity |
| JP2010249097A (en) * | 2009-04-20 | 2010-11-04 | Toshiba Corp | Method of assembling crown or band of runner and method of assembling runner in francis type water turbine or francis type pump turbine |
| CN201461204U (en) * | 2009-07-03 | 2010-05-12 | 武汉大学 | Novel runner cone |
| DE102009039119B4 (en) * | 2009-08-28 | 2022-11-03 | Pfeiffer Vacuum Gmbh | Vacuum pump and arrangement with vacuum pump |
| CN201884184U (en) * | 2010-06-24 | 2011-06-29 | 宜宾富源发电设备有限公司 | Horizontal water turbine with rearmounted control ring and split cover plate |
| JP5687482B2 (en) * | 2010-12-15 | 2015-03-18 | 株式会社東芝 | Hydraulic machine runner |
| DE102015219331A1 (en) * | 2015-10-07 | 2017-04-13 | Voith Patent Gmbh | Radial impeller |
| CN105927451A (en) * | 2016-06-06 | 2016-09-07 | 哈尔滨电机厂有限责任公司 | Trapezoid groove mosaic structure for blades and upper canopy of water turbine model runner |
-
2017
- 2017-07-28 AT ATA50629/2017A patent/AT520226B1/en active
-
2018
- 2018-06-07 CN CN201880046640.2A patent/CN110914552B/en active Active
- 2018-06-07 WO PCT/AT2018/060116 patent/WO2019018866A1/en active Application Filing
- 2018-06-07 EP EP18733159.0A patent/EP3658779B1/en active Active
- 2018-06-07 CA CA3060605A patent/CA3060605A1/en active Pending
-
2019
- 2019-11-26 CL CL2019003448A patent/CL2019003448A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AT520226B1 (en) | 2021-08-15 |
| CN110914552B (en) | 2021-11-23 |
| EP3658779B1 (en) | 2022-09-14 |
| CL2019003448A1 (en) | 2020-03-20 |
| CN110914552A (en) | 2020-03-24 |
| EP3658779A1 (en) | 2020-06-03 |
| WO2019018866A1 (en) | 2019-01-31 |
| AT520226A1 (en) | 2019-02-15 |
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