Patent Application
20240392684
The invention relates to a method for carrying out servicing measures on an energy conversion installation, and to an energy conversion installation.
Various requirements are set for gas turbines in energy conversion installations.
Said gas turbines can be machines for supplying the basic demand, or for compensating load changes, in particular by virtue of renewable energy sources, the input by the latter into the grid being variable. Requirements can be different locations, cooling possibilities, fuels, etc.
There are moreover also various requirements set for the desired service intervals or for modifications and improvements by virtue of different initial models.
It is therefore an object of the invention to specify modifications which correspond to different operating conditions or customer requirements.
The object is achieved by a method, and by an energy conversion installation, in which object or method a corresponding existing gas turbine is provided or correspondingly modified or newly manufactured, respectively.
Further advantageous measures which can be combined with one another in an arbitrary manner in order to achieve further advantages are set forth in the dependent claims.
In the figures:
The figures and the description represent only exemplary embodiments of the invention.
The gas turbine machine 100 in the interior has a rotor 103 which is mounted so as to be rotatable about a rotation axis 102 and has a turbine blade 120, said rotor 103 also being referred to as the turbine rotor.
Along the rotor 103 there are in sequence an intake housing 104, a compressor 105, a combustion chamber 110, in particular an annular combustion chamber, which in an exemplary manner is shaped in the manner of a torus and has a plurality of coaxially disposed burners 107, a turbine 108, and the exhaust gas housing 109.
The annular combustion chamber 110 communicates with a advantageously annular hot-gas duct 111. In the latter, for example four sequential turbine stages 112 form the turbine 108.
Each turbine stage 112: I, II, III, IV is advantageously formed from two blade rings.
When viewed in the flow direction of an operating medium 113 in the hot-gas duct 111, a row of vanes 115 is followed by a row of rotor blades 125 formed from rotor blades 120.
The vanes 130 here are fastened to a gas turbine housing 138 of a stator 143, whereas the rotor blades 120 of a row of rotor blades 125 are attached to the rotor 103, for example by means of a turbine disk 133.
A generator 5 (
During the operation of the gas turbine 100, air 135 is suctioned through the intake housing 104 and compressed by the compressor 105. The compressed air provided at the turbine-side end of the compressor 105 is guided to the burners 107 in a combustion chamber 110 and therein mixed with a fuel. The mixture in the combustion chamber 110 is then combusted while forming the operating medium 113. From there, the operating medium 113 flows along the hot-gas duct 111, passing the vanes 130 and the rotor blades 120. The operating medium 113 relaxes on the rotor blades 120 so as to transmit an impulse such that the rotor blades 120 drive the rotor 103, the latter in turn driving the work machine coupled thereto.
The components exposed to the hot operating medium 113 are subjected to thermal stress during the operation of the gas turbine 100. The vanes 130 and the rotor blades 120 of the turbine stage 112, the latter when viewed in the flow direction of the operating medium 113 being the first turbine stage 112, are thermally stressed to the highest extent, apart from the heat shield elements which clad the combustion chamber 110.
In order to withstand the temperatures prevailing therein, these vanes 130 and rotor blades 120 can be cooled by means of a coolant.
Likewise, substrates of the components may have an oriented structure, i.e. said substrates are monocrystalline (SX structure) or have only longitudinally oriented grains (DS structure). Superalloys based on iron, nickel or cobalt are used as a material for the components, in particular for the turbine blades 120, 130 and the components of the combustion chamber 110, for example.
Such superalloys are advantageously known from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435, or WO 00/44949, or are set forth in
Likewise, the blades 120, 130 may have anti-corrosion coatings: MCrAlX; M is at least one element from the group comprising cobalt (Co), nickel (Ni); X is an active element and represents yttrium (Y) and/or tantalum (Ta), and/or at least one rare earth element or hafnium (Hf) or iron (Fe). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1, or EP 1 306 454 A1.
A thermal insulation layer may also be present on the MCrAlX, the former being composed of, for example, ZrO2, Y2O3-ZrO2, i.e. said thermal insulation is not, partially or completely stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide and/or erbium oxide and/or ytterbium oxide.
The vane 130 has a vane root (not illustrated here) that faces the gas turbine housing 138 of the turbine 108, and a vane head that is opposite the vane root. The vane head faces the rotor 103 and is established on a fastening ring 140 of the stator 143.
In order to achieve a comparatively high rate of efficiency, the combustion chamber 110 is conceived for a comparatively high temperature of an operating medium, said temperature being approximately 1273 K to 1873 K. In order to achieve a comparatively long operating time even at these operating parameters which are unfavorable for the materials, the combustion chamber wall 153 of the combustion chamber 110, on that side thereof that faces the operating medium, is provided with an interior cladding formed by heat shield elements 155. Each heat shield element 155 is made from an alloy and on the side that faces the operating medium is equipped with a particularly heat resistant protective layer (MCrAlX layer and/or a ceramic coating) or is made from a material resistant to high temperatures (solid ceramic bricks).
These protective layers of the metallic heat shield elements 155 can be similar to those of the turbine blades, MCrAlX thus meaning, for example: M is at least one element of the group comprising iron (Fe), cobalt (Co), nickel (Ni); X is an active element and represents yttrium (Y) and/or silicon (Si) and/or tantalum (Ta) and/or at least one rare earth element or hafnium (Hf) and/or iron (Fe). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1, or EP 1 306 454 A1.
A ceramic thermal insulation layer may also be present on the MCrAlX, the former being composed of, for example, ZrO2, Y2O3-ZrO2, i.e. said thermal insulation is not, partially or completely stabilized by yttrium oxide and/or erbium oxide, ytterbium oxide and/or hafnium oxide.
Many coating methods are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. For improved resistance to thermal shock, the thermal insulation layer can have porous grains or grains with micro-fissures or macro-fissures.
Refurbishment means that heat shield elements 155 after the use thereof optionally have to be relieved of protective layers (for example by sandblasting). The removal of the anti-corrosion and/or anti-oxidation layers or products, respectively, takes place thereafter. Cracks in the heat shield element 155 are optionally also repaired. Re-coating of the heat shield elements 155 takes place thereafter, and the heat shield elements 155 are reused.
By virtue of the high temperatures in the interior of the combustion chamber 110, a cooling system can moreover be provided for the heat shield elements 155, or for the holding elements of the latter, respectively. The heat shield elements 155 in this instance are hollow, for example, and optionally have cooling bores that open into the combustion chamber space 154 (not illustrated).
The turbomachine can be a gas turbine of an aircraft or of a power station for generating electricity, a steam turbine or a compressor.
The blade 120, 130, sequentially along the longitudinal axis thereof, has a fastening region 400, adjacent thereto a blade platform 403, as well as a turbine blade 406, and a blade tip 415.
As a vane 130, said blade 120 can have a further platform on the blade tip 415 of said vane 130 (not illustrated).
A blade root 183, which serves for fastening the rotor blades 120, 130 to a shaft or a turbine disk 133 is formed in the fastening region 400 (
The blade root 183 is designed as a hammer head, for example. Other designs as a fir-tree or a dovetail root are possible.
The blade 120, 130 for a medium that flows past the turbine blade 406 has an inlet edge 409 and an outlet edge 412.
For example, in conventional blades 120, 130, solid metallic materials, in particular superalloys, are used in all regions 400, 403, 406 of the blade 120, 130.
Such superalloys are advantageously known from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435, or WO 00/44949, or are set forth in
The blade 120, 130 here can be made by a casting method, also by means of oriented solidification, by a forging method, by a milling method, or combinations thereof.
Workpieces having a monocrystalline structure or structures are used as components for machines that in operation are exposed to high mechanical, thermal and/or chemical stress.
The manufacturing of monocrystalline workpieces of this type takes place by way of oriented solidification from the melt, for example. This here is a casting method in which the liquid metallic alloy solidifies so as to form the monocrystalline structure, i.e. the monocrystalline workpiece, or solidifies in an oriented manner.
Dendritic crystals here are oriented along the thermal flow and form either a columnar crystalline grain structure and thus grains which run across the entire length of the workpiece and here, following the general terminology, are referred to as solidified in an oriented manner, or a monocrystalline structure, i.e. the entire workpiece is composed of a single crystal. In these methods, the transition to the equiaxed (polycrystalline) solidification has to be avoided because transversal and longitudinal grain boundaries which destroy the positive properties of the oriented-solidification or monocrystalline component are configured by necessity as a result of the non-oriented growth. When reference is made generally to structures which are solidified in an oriented manner, this thus also refers to monocrystals which have no grain boundaries or at most small-angle grain boundaries, as well as to columnar crystalline structures which indeed have grain boundaries running in the longitudinal direction but do not have any transversal grain boundaries. In the case of these second crystalline structures mentioned, reference is also made to directionally solidified structures.
Such methods are known from US patent document 6 024 792 and EP 0 892 090 A1.
Likewise, the blades 120, 130 may have anti-corrosion or anti-oxidation coatings: in particular MCrAlX; M is at least one element from the group comprising cobalt (Co) or nickel (Ni); X is an active element and represents yttrium (Y) and/or tantalum (Ta), and/or at least one rare earth element and/or hafnium (Hf) and/or iron (Fe). Such alloys are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1, or EP 1 306 454 A1.
The density is advantageously 95% of the theoretical density.
A protective aluminum oxide layer (TGO=thermal grown oxide layer) is formed (as an intermediate layer or as the outermost layer) on the MCrAlX layer.
A thermal insulation layer may also be present on the MCrAlX, the former advantageously being the outermost layer and composed of, for example, ZrO2, Y2O3-ZrO2, i.e. said thermal insulation is not, partially or completely stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide and/or erbium oxide and/or ytterbium oxide.
The thermal insulation layer covers the entire MCrAlX layer.
Other coating methods are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. For improved resistance to thermal shock, the thermal insulation layer can have porous grains or grains with micro-fissures or macro-fissures. The thermal insulation layer is thus advantageously more porous than the MCrAlX layer.
Refurbishment means that components 120, 130 after the use thereof optionally have to be relieved of protective layers (for example by sandblasting). The removal of the anti-corrosion and/or anti-oxidation layers or products, respectively, takes place thereafter. Cracks in the component 120, 130 are optionally also repaired. Re-coating of the component 120, 130 takes place thereafter, and the component 120, 130 is reused.
The blade 120, 130 can be embodied so as to be hollow or solid. When the blade 120, 130 is to be cooled, said blade 120, 130 is hollow and optionally also has cooling bores 418 (indicated by dashed lines).
The gas turbine 100 by way of a transmission 4 or a clutch 4 is coupled to a generator 5 for generating electric power.
The generator 5 by way of a clutch 2 is likewise connected to a steam turbine 6.
Steam turbines 6 are present when this is a combined cycle installation. An energy conversion installation 1 can also have only a gas turbine 100 without steam turbine 6.
If and when present, a condenser 7 is connected to the steam turbine 6. The exhaust gas from the gas turbine 100 by way of a diffuser 8 flows into a heat recovery installation 9 in which the hot exhaust air is used for generating steam.
An exhaust air chimney 10 is likewise present.
The concept lies in carrying out servicing measures on an energy conversion installation, wherein the energy conversion installation has at least the following machines: at least one gas turbine; at least one generator; and optionally at least one steam turbine; wherein repairs are carried out on the at least one machine, in particular a defective component or defective components of the at least one machine either is/are or will be replaced by a new, identical component or new, identical components and/or repaired; and wherein, while carrying out these repairs, further measures for extending the service life of machines or the components thereof and/or further measures for optimizing (the efficiency) of machines or the components thereof are carried out.
In particular, the defective components comprise turbine blades or the coatings thereof; and/or burners or burner components; and/or compressor blades or the coatings thereof; and/or combustion chamber bricks.
The defective components can advantageously comprise only turbine blades.
The defective components can advantageously comprise only turbine blades or the coatings thereof as well as burners or burner components.
As further measures only measures for extending the service life are advantageously carried out.
As further measures only measures for optimizing are advantageously carried out.
As further measures, measures for extending the service life of components and measures for optimizing components can likewise be carried out.
In the case of the servicing measures, advantageously at least one measure, in particular at least two identical, or at least two different, measures for extending the operating life of machines or the components thereof, selected from the group comprising: bearing of the rotor, burner, compressor blade, compressor housing, turbine blades, gas turbine housing, blade carrier, heat shields or combustion chamber bricks, seals, transition combustion chamber to turbine, cooling and/or monitoring apparatuses, is/are carried out.
In the case of the servicing measures, advantageously at least one measure, in particular at least two identical, or at least two different, measures for optimizing machines or the components thereof, selected from the group comprising: increased efficiency, improved cooling, burner, compressor blade, compressor housing, turbine blades, gas turbine housing, blade carrier, heat shields or combustion chamber bricks, seals and/or transition combustion chamber to turbine, is/are carried out.
The individual measures are described in more detail hereunder, said measures being able to be combined in an arbitrary manner with one another, depending on the requirement:
The following machine types are advantageously achieved therewith:
These measures or models, respectively, will be explained in more detail by means of drawings and classified in terms of the intentions of said measures or models, respectively.
For a longer service life of the gas turbine machine 100, the rotor bearing 31 of the rotor 103, in the flow direction 11 of the gas turbine machine 100, at the beginning of the compressor 105 and close to the intake housing 104 however has a length of at least 370 mm, and in particular a length of at most 500 mm, or in the event of an upgrade or revision is designed so as to be at least 5% longer so as to achieve less contact pressure per unit area.
In the event of a service, or at one of the next service intervals, the installed bearing does not have to be replaced, or never be replaced at all, or said bearing can be utilized until the end of the life of the gas turbine machine 100.
Likewise, said bearing can be replaced in the context of a very large servicing measure when the replacement of a bearing constitutes only a minor temporal input and can in particular take place in parallel, or is even facilitated as a result of the latter, respectively. The same applies in an analogous manner to a bearing of the rotor 103 in the region of the exhaust gas housing 109 (
The burner 107′ of a gas turbine machine 100 in
This likewise applies when petroleum or other fuels are used.
The burner system having the burner 107 (
For a longer service life, the fuel-supplying means such as pipes, in particular also of the burner 107, in particular of gas, are at least partially, in particular completely, provided on the inside with a diffusion coating, in particular calorized, that is to say that internal calorizing (or chrome plating, . . . ) is used in this instance.
The internal coating can also be carried out with the means in the installed state.
This increases the service life, or else the efficiency, by virtue of reduced corrosion.
The service life of the burner 107′ can thus be individually adapted to the respective operating conditions.
Combustion chambers 110 refer to known systems such as annular combustion chambers or CANs.
The materials of the compressor housings 19′, 19″, in particular when the latter are in two parts, are typically made from the same first material, in particular from gray cast iron. With a view to an improved modification, the internal compressor housing 19″ as a vane carrier is manufactured from a distinctly different second material, in particular from cast steel.
Different in the case of the first and the second material means that at least one alloy element in terms of the proportion by weight thereof differs by 10% and/or at least one further alloy element is present or absent and/or a different manufacturing method has been applied, or has a different, distinguishable microstructure.
In comparison to stages III and IV, stages I and II are exposed to the higher thermal stresses. Here, corresponding modifications of the substrate material, in particular in the form of directionally solidified alloys (SX, DS) or additional or improved cooling, respectively, in particular of the blade tip 415, are used.
Such a blade 120, 130 advantageously has a directionally solidified structure SX, DS in the form of a columnar solidified microstructure such as, in particular, alloys with the suffix DS in
A further type of blade 120, 130 in the substrate comprises a monocrystalline microstructure such as an alloy with the suffix SX or CMSX . . . in
The blades 120, 130 have in particular cooling bores on the lateral faces of the blade platform 403, wherein the blade tips 415 are in particular also cooled.
A ceramic coating (TBC) based on partially stabilized YSZ (yttrium-stabilized zirconium oxide) has a porosity of 12±4%.
A further type of blade 120, 130 comprises a segmented TBC based on yttrium-stabilized zirconium oxide.
A further type of blade 120, 130 is composed of a directionally solidified structure DS in the substrate, i.e. in the form of a columnar microstructure and having a TBC based on YSZ without segmentation.
The alignment and disposal of the cooling air bores 399, 405, 418 is only schematic. The cooling bores 399, 405, 418, 501 (
As a result of cooling by cooling air that is retrieved from the compressor, the efficiency drops, the latter optionally being partially compensated for by the cooling effect.
The blade tip 500 has two webs 503, 505 which run on the outside and, when viewed in the cross section, enclose a depression 504. The original depression 504 is indicated by dashed lines and is configured so as to be rectangular in the cross section.
According to the invention, the blade tip 500 in the depression 504 has a step-shaped shoulder 507 which directly adjoins the web 505 of the intake side and thus initially represents additional material in the depression 504. However, for improved cooling of the blade tip 500, a cooling air bore 501 from the interior of the rotor blade 120 now runs through the shoulder 507.
The cooling air bore 501 is advantageously aligned along the longitudinal axis 121 of the turbine blade 120.
The stage IV is fastened in the region of this blade carrier 50.
When viewed in the flow direction 11, there is a front plenum 54 and a rear plenum 57 outside the hot-gas duct 111, said plenums 54, 57 for technical reasons having different pressures. The front plenum 54, when viewed in the flow direction 11, is advantageously present behind the rotor blade of stage III and in the region above the vane IV.
Illustrated in the blade carrier 50 in
By virtue of the lower pressure, less cooling air is supplied to the vane 401. The supply of the new duct 60 in the axial flow direction through the gas turbine lies behind the rotor blade 402 and not between the vane and the rotor blade of stage IV. Less cooling air is consumed, this leading to a higher rate of efficiency.
The radius 72 on the flow-side end of the heat shield/combustion chamber brick 155 and the opposite radius 75 of the vane 130 of stage I are identically embodied. The intention is to avoid a projection or an undercut in the heat shield/combustion chamber brick 155, in which dirt could accumulate or erosion occurs.
The individual elements 81, 83 of the vane carrier 50 have a gap 80 which here is configured in the shape of a labyrinth or in an S-shaped manner. The lower consumption of cooling air is achieved in that the front element 81 in the flow direction 11 has a first cam 82, and the rear, second element 83 in the flow direction 11 has a second cam 85 configured above said first cam 82 such that an S-shaped gap 80 is configured and the cam 82 of the front element 81 forms part of the hot-gas duct 111.
When viewed in the flow direction, the opening of the gap thus lies at the rear of the hot-gas duct 111.
The combustion chamber bricks 601, 602, or 603, 605, respectively, when viewed in the flow direction 11, are disposed in a row and in the circumferential direction.
When viewed in the flow direction 11, modified combustion chamber bricks 603, 605; 604 are present at the end, wherein further such combustion chamber bricks are disposed in the circumferential direction about the rotation axis 102.
The modified combustion chamber bricks 603, 604, 605, advantageously made completely from ceramic, when viewed in the flow direction 11, advantageously in the two last rows of the combustion chamber 110 ahead of the entry or the transfer to the vanes 130 or the first rotor blade row 120 of stage I, are configured so as to be increasingly thicker in the flow direction 11 such that a spoiler effect results. Close to the rotor hub, only one combustion chamber brick 604 is advantageously configured in the shape of a spoiler, whereas further radially distal, at the outer end of the combustion chamber 110, at least the penultimate and the last row of the combustion chamber bricks 603, 605 conjointly have a gradual increase in thickness in the flow direction.
This is however not intended to be limiting.
As a result of this spoiler effect, less erosion as well as a constriction of the hot-gas flow occurs, this leading to an increase in the rate of efficiency.
An undercut 41 is present along the lateral face having the depressions 40 on the rear side 43 of the combustion chamber brick 155.
A section through two combustion chamber bricks according to
This leads to a reduced consumption of coolant because there is less cooling input.
One or a plurality of additional depressions 630 and a seal are incorporated in this contact face 600 so as to reduce leakages in this region (
Shown in
The original position of the vane of the swirler is indicated by dashed lines on the vane 73′, whereas the dashed line on the vane 73″ indicates how the latter is torsioned along the longitudinal axis thereof, the latter running parallel to the inlet edge.
Gas turbines can be operated as stand-alone units in order to operate a generator, but are often also operated in combination with steam turbines in a combined cycle installation.
As a result of the higher output generated by the gas turbine, the output capability of a steam turbine 6 has also to be adapted. This takes place in particular in that, as is illustrated in
The combustion stability and the dynamic also have a very high influence on the service life of the system such that a control system 90 which registers the combustion dynamic and the acceleration is installed here (
Some of the measures when servicing can be carried out conjointly because the measures conjointly can be carried out in a simpler manner and optionally in parallel.
Some measures can be offered to the operator of the installation and installed free of charge, in order for the next service intervals to be allowed to be extended or even skipped, or in order to reduce operating costs by increasing the rate of efficiency/a higher efficiency in which the service provider takes a share.
Considerations in terms of service life extension, efficiency, higher temperatures and the consumption of coolant play a role here.
In servicing measures of an energy conversion installation 1 which has at least a gas turbine 100, a generator 5 and optionally a steam turbine 6 having corresponding respective auxiliary apparatuses, service contracts which offer the operator of the energy conversion installation a service and maintenance contract which includes that a specific operating performance (service life) at specific output parameters in association with predefined service intervals is guaranteed, are often agreed.
For the service provider, this means that said service provider not only refurbishes items that have to be refurbished at the time, because said item can no longer be utilized or utilized only in the short term, so that said service provider when servicing also considers carrying out measures which permit the period up to the next service interval or to the next but one service interval to be extended.
For example, new burners which are calorized can also be installed when replacing turbine blades so that servicing measures pertaining to the burner component are not necessary at the next or at the next but one interval. Downtime is thus avoided.
Likewise, an extension of the service life can be carried out during a servicing measure, or a servicing measure can be brought forward, such that the next servicing measure is significantly shortened because measures relating to the disassembly of bearings, the disassembly of turbine blades, the replacement of combustion chamber bricks, modifications to the housing, etc., include different maintenance times.
This is also a result of certain measures being able to be carried out in parallel.
The flexible refurbishment comprises enhanced remote monitoring and diagnostic functions as part of the Omnivise Digital Service portfolio, as well as deliveries of spare parts, the maintenance according to plan, as well as output guarantees during the operating period of the installation. The combined gas and steam power station, by way of the high rate of efficiency under partial load and the high operating flexibility thereof, including the associated services in the context of this flexible refurbishment will function as an addition to the fluctuating renewable energy sources in the region.
The protection of the investments of the power plant operation as a result of a first-class service for the rotating machines is the key to the philosophy of a successful service provider.
The long-term flexible service takes one step further and offers a maintenance program which is individually tailored to the special needs and requirements. Whether the power plant operator wishes to maximize his/her production in that said power plant operator extends the time between the inspections, whether the inspections are to take place during the downtimes of the installation according to plan, whether the life-cycle costs are to be optimized by a replacement of components as a function of the state, or whether the operation is to take place free of predefined inspection dates: the long-term flexible refurbishment can be adapted to requirements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 207 479.0 | May 2019 | DE | national |
This application is a continuation of U.S. Ser. No. 17/609,378 filed 6 Nov. 2021, which is a US National Stage of International Application No. PCT/EP2020/061141 filed 22 Apr. 2020, and claims the benefit thereof. The International Application claims the benefit of German Application No. DE 10 2019 207 479.0 filed 22 May 2019. All of the applications are incorporated by reference herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17609378 | Nov 2021 | US |
| Child | 18793761 | US |
