Gas turbine blade for reusing cooling air and turbomachinery assembly and gas turbine provided therewith

Abstract

Blade (1) for a gas turbine (10), the blade (1) comprising: - a platform (100) with a top surface (101); and - an airfoil (200) extending radially outward from the top surface (101) of the platform (100), the airfoil (200) comprising a pressure surface (202) and a suction surface (204) meeting at a leading edge (206) and a trailing edge (208); and wherein the platform (100) further comprises: a pressure side (102) arranged in the direction of the pressure surface (202) of the blade (200) and having a pressure-side side surface (103); a suction side (104) arranged in the direction of the suction surface (204) of the blade (200) and having a suction-side side surface (105); a leading edge side (106) disposed toward the leading edge (206) of the airfoil (200) and comprising a leading edge side surface (107); and a trailing edge side (108) disposed toward the trailing edge (208) of the airfoil (200); wherein at least a portion of an edge between the suction-side side surface (105) and the top side (101) of the platform (100) has a groove portion (9), wherein the blade (1) further comprises one or more cooling channels (400) embedded in the platform (100), wherein at least one of the one or more cooling channels (400) comprises an outlet (401) for the cooling air, and wherein the outlet (401) is arranged on the pressure-side side surface (103) of the platform (100); wherein a distance (D22) of the outlet (401) from the leading edge side surface (107) is smaller than a distance (D1) of the groove section (9) from the leading edge side surface (107), the distances (D1, D22) being measured parallel to a chord of the airfoil (200).

Description

[0001] The present invention relates to gas turbines and to a turbomachinery assembly, and more particularly to turbine blades for reusing cooling air used for gas turbines and turbomachinery assemblies.

[0002] Cooling a gas turbine blade (hereinafter also referred to as a blade) is accomplished in several ways. Efficient cooling of the blades leads to increased efficiency of the gas turbine and extends the service life of the blades and therefore the gas turbine.

[0003] The blade generally comprises an airfoil (also called an aerodynamic airfoil) extending from a top surface of a platform, and a root extending from a bottom surface of the platform in a direction opposite to the airfoil. During operation of the gas turbine, the airfoil and the top surface of the platform are located in the hot gas path of the gas turbine. One of the areas of the blade that is subjected to high mechanical and thermal stresses during operation of the gas turbine and is therefore prone to mechanical fatigue and eventual failure is the area where the airfoil meets the top surface of the platform. Therefore, it is advantageous to design this transition region, i.e.to cool the area where the blade meets / connects to the top of the platform in order to extend the operating life or cyclic life of the blades and therefore the gas turbine.

[0004] To cool gas turbine components, a portion of the air is taken from the compressor section of the gas turbine or external cooling air is used as cooling air. Therefore, it is advantageous that once the cooling air has been used to cool one section of the gas turbine, the same cooling air is then reused to cool another section of the gas turbine.

[0005] DE 10 2015 203 871 A1 discloses a rotor of a turbine of a gas turbine with improved cooling air guidance.

[0006] US 2017 / 0 022 839 A1 discloses an arrangement of components in a gas turbine engine.

[0007] Accordingly, it is an object of the present disclosure to provide a blade for a gas turbine, wherein the transition region, i.e., the region where the blade meets / connects to the top of the platform, or the regions of the platform adjacent to the transition region (hereinafter also referred to as the adjacent regions) are efficiently cooled. It is advantageous if the cooling of the transition region and / or the adjacent regions is carried out by the cooling air that is reused, i.e., the cooling air used to cool the transition region and / or the adjacent regions has previously been used to cool another portion of the gas turbine or has been used for another purpose, e.g., as the seal purge air for a seal between two adjacent blades arranged on a runner of the gas turbine.

[0008] The above objects are achieved by a blade for a gas turbine according to claim 1. Advantageous embodiments are provided in the dependent claims. The features of the independent claim can be combined with features of the claims dependent on the independent claim, and the features of the dependent claims can be combined with each other.

[0009] In a first aspect of the present technology, a blade for a gas turbine is provided. The blade includes a platform and an airfoil extending from the platform. The platform includes a top surface, with the airfoil extending from the top surface of the platform.

[0010] The airfoil contains a pressure surface and a suction surface that meet at a leading edge and a trailing edge of the airfoil.

[0011] The platform includes: a pressure side arranged towards the pressure surface of the airfoil, a suction side arranged towards the suction surface of the airfoil, a leading edge side arranged towards the leading edge of the airfoil, and a trailing edge side arranged towards the trailing edge of the airfoil.

[0012] The pressure side of the platform includes a pressure-side side surface. The pressure side of the platform may include a portion (hereinafter also referred to as the pressure-side portion) of the top surface of the platform.

[0013] The suction side of the platform includes a suction side surface. The suction side of the platform may include a portion (hereinafter also referred to as the suction side portion) of the top surface of the platform.

[0014] The suction-side side surface and the pressure-side side surface of the platform can be opposite side surfaces of the platform that face away from each other.

[0015] In the blade, at least a portion of an edge between the suction side surface and the top of the platform includes a groove portion.

[0016] Preferably, the groove portion is provided on a rotating blade of the gas turbine.

[0017] The leading edge side of the platform has a leading edge side surface.

[0018] The groove portion may be spaced from the leading edge side surface.

[0019] The trailing edge side of the platform may include a trailing edge side surface.

[0020] The groove portion may be spaced from the trailing edge side surface.

[0021] Alternatively, the groove portion may be continuous with the trailing edge side surface, i.e., the groove portion may start at the trailing edge side surface and may extend toward the leading edge side surface of the platform.

[0022] In the blade, a ratio between the chord length of the blade and the length of the groove section may be greater than or equal to 1.05 and less than or equal to 8.1.

[0023] The chord length is preferably measured at a height of 5%-10% of the blade or vane height above the platform surface. The chord length can be measured in a plane section of the blade parallel to the rotation axis. It can be measured from the leading edge to the trailing edge, specifically by measuring the maximum distance between the leading edge and the trailing edge, with the measurement points located on the lines at right angles to the suction side surface or the pressure side surface.

[0024] In the blade, a rise of the groove section may be greater than or equal to 0.8 and less than or equal to 3, that is, the rise of the groove section may be between 0.8 and 3.

[0025] In the blade, a ratio of a chord length of the airfoil and a length of a first non-scoured edge region may be greater than or equal to 1.03 and less than or equal to 5.9. The first non-scoured edge region may be at least a portion of the edge between the suction-side side surface and the top of the platform. The first non-scoured edge region may be located laterally between an airfoil chord starting point at the leading edge of the airfoil and the scoop portion when viewed in a direction perpendicular to the airfoil chord. The lengths may be measured parallel to the airfoil chord of the airfoil.

[0026] The platform may include a bottom surface opposite the top surface of the platform. The groove portion may be spaced from the bottom surface by a portion of the suction-side side surface.

[0027] The blade may include a fillet disposed around at least a portion of the airfoil. The fillet may be disposed in or at a region where the airfoil is connected to the platform. At least a portion of the fillet may be disposed between the airfoil and the fillet portion. In other words, at least a portion of the fillet may be disposed directly between the suction surface of the airfoil and the fillet portion when viewed in a direction perpendicular to the chord of the airfoil.

[0028] The blade includes one or more cooling channels formed in the platform. At least one of the one or more cooling channels includes an outlet for cooling air. The outlet is located on the pressure-side surface of the platform.

[0029] The leading edge side of the platform may include a leading edge side surface.

[0030] For the blade, the distance between the outlet and the leading edge side surface of the platform is smaller than the distance between the groove section and the leading edge side surface of the platform. The distances are measured parallel to the chord of the blade.

[0031] Optionally, in addition to the above, the difference between the distances may be less than the distance of the outlet from the leading edge side surface of the platform. The distances may be measured parallel to the chord of the airfoil.

[0032] In the blade, a distance of the outlet from the leading edge side surface of the platform may be equal to or greater than a distance of the groove portion from the leading edge side surface of the platform and / or equal to or less than a sum of the distance of the groove portion from the leading edge side surface of the platform and a length of the groove portion. The length of the groove portion and the distances may be measured parallel to the chord of the blade.

[0033] In a second aspect of the present technique, a turbomachine assembly, hereinafter also referred to as an assembly, is presented. The assembly includes a plurality of blades arranged on an impeller. The plurality of blades includes at least one first blade. The at least one first blade is a blade according to one of the above embodiments of the blade presented above according to the first aspect of the present technique. A cooling air flow path may be arranged adjacent to the suction-side surface of the first blade.

[0034] In the arrangement, the plurality of blades may include at least one second blade disposed adjacent to the at least one first blade. The at least one second blade may be a blade including the grooved portion as disclosed above in the first aspect of the present technique, and may further include the one or more cooling channels formed in the platform and having the outlet disposed on the pressure-side surface of the platform, as discussed above.

[0035] In a most preferred embodiment, all blades may be completely identical, and may include cooling holes on the pressure side and / or perhaps on the suction side of the platform, and all blades may include the groove section.

[0036] The cooling air flow path may be arranged between the second blade and the suction side surface of the first blade.

[0037] In the arrangement, the plurality of blades may include at least one third blade disposed adjacent to the at least one first blade.

[0038] The at least one third blade, disposed adjacent to the at least one first blade, includes a platform and an airfoil extending from the platform. The platform may include a top surface, and the airfoil may extend from the top surface of the platform.

[0039] The third blade airfoil includes a pressure surface (also referred to as a pressure side or a concave surface / side) and a suction surface (also referred to as a suction side or a convex surface / side). The pressure surface and the suction surface meet at a leading edge and a trailing edge of the third blade airfoil.

[0040] The platform of the third blade includes: a pressure side arranged towards the pressure surface of the airfoil, a suction side arranged towards the suction surface of the airfoil, a leading edge side arranged towards the leading edge of the airfoil, and a trailing edge side arranged towards the trailing edge of the airfoil.

[0041] The pressure side of the third bucket platform may include a pressure-side side surface. The pressure side of the platform may include a portion (hereinafter also referred to as a pressure-side portion) of the top surface of the third bucket platform.

[0042] The suction side of the third blade platform may include a suction side surface. The suction side of the third blade platform may include a portion (hereinafter also referred to as a suction side portion) of the top surface of the third blade platform.

[0043] The third blade further comprises one or more cooling channels formed in the platform of the third blade, and wherein at least one of the one or more cooling channels of the third blade comprises an outlet for cooling air, and wherein the outlet is arranged on the pressure-side surface of the platform of the third blade.

[0044] In the arrangement, a distance of the outlet of the third blade from the leading edge side surface of the platform of the third blade may be smaller than a distance of the groove portion of the first blade from the leading edge side surface of the platform of the first blade. The distances may be measured parallel to the chords of the blades of the respective blades.

[0045] In the arrangement, a distance of the outlet of the third blade from the leading edge side surface of the platform of the third blade may be smaller than a distance of the groove portion of the first blade from the leading edge side surface of the platform of the first blade. Additionally, a difference between the distances may be smaller than the distance of the outlet of the third blade from the leading edge side surface of the platform of the third blade. The distances may be measured parallel to the chords of the blades of the respective blades.

[0046] In the arrangement, the outlet of at least one of the one or more cooling channels of the third blade may be positioned directly facing the groove portion of the first blade.

[0047] Preferably, the cooling channel and the groove section are at the same radial distance.

[0048] In the arrangement, a distance between a lower edge of the groove portion of the at least one first blade and the pressure-side surface of the blade disposed adjacent to the at least one first blade may be equal to or greater than 0.5 times and equal to or less than 3 times a horizontal distance between the lower edge of the groove portion and a top edge (ie, an edge or boundary of the groove portion adjacent to the top of the platform) of the groove portion.

[0049] In a third aspect of the present technology, a gas turbine is presented. The gas turbine includes a turbomachine assembly. The turbomachine assembly is in accordance with one of the above embodiments of the above-described assembly according to the second aspect of the present technology.

[0050] The above-mentioned attributes and other features and advantages of the present technique and the manner of achieving them will become more apparent with reference to the following description of embodiments of the present technique taken in conjunction with the accompanying drawings, wherein the present technique itself will be better understood, wherein: Fig. 1 shows a section of a gas turbine incorporating a blade of the present technique; Fig. Figure 2 schematically illustrates a turbomachine assembly utilizing a blade of the present technique; Fig. Figure 3 schematically illustrates a plan view of a conventional gas turbine blade; Fig. 4A schematically illustrates a plan view of an exemplary embodiment of a gas turbine blade according to the present technique; Fig. 4B schematically illustrates operation of the bucket of the present technique for cooling a transition region where an airfoil meets a platform of the bucket and / or for cooling a region(s) of the platform adjacent to the transition region in accordance with the present technique; Fig. 5 schematically illustrates a plan view of another exemplary embodiment of the blade according to the present technique; Fig. 6 schematically illustrates a plan view of yet another exemplary embodiment of the blade according to the present technique; Fig. 7 schematically illustrates a plan view of a third blade according to the present technique; Fig. 8A is a perspective view illustrating a conventional turbomachinery assembly in which a conventional blade as shown in Fig. 3 is shown; Fig. 8B is a portion of a cross-sectional view of the conventional turbomachinery assembly according to Fig. 8A in cross-section along line II'; Fig. 9A is a perspective view illustrating an exemplary embodiment of a turbomachine assembly of the present technique incorporating a bucket of the present technique; Fig. 9B shows a partial cross-sectional view of the turbomachinery assembly according to Fig. 9A in cross-section along the line II-II'; Fig. 10A schematically illustrates another exemplary embodiment of the turbomachine assembly of the present technique incorporating a blade of the present technique; Fig. 10B shows a partial cross-sectional view of the turbomachinery assembly according to Fig. 10A in cross-section along the line III-III'; Fig. 11A schematically illustrates yet another exemplary embodiment of the turbomachine assembly of the present technique incorporating a blade of the present technique; Fig. 11B shows a partial cross-sectional view of the turbomachinery assembly according to Fig. 11A in cross-section along the line IV-IV'; Fig. 12A the turbomachinery arrangement according to Fig. 11A schematically illustrates and schematically depicts exemplary dimensions of the blade of the present technique; Fig. 12B the turbomachinery arrangement according to Fig. 11B schematically illustrates and schematically depicts exemplary dimensions of the blade of the present technique; and Fig. 12C schematically illustrates yet another exemplary embodiment of the turbomachine assembly of the present technique and schematically depicts exemplary dimensions of the blade of the present technique.

[0051] The above-mentioned and other features of the present technique are described in detail below. Various embodiments are described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be stated that the illustrated embodiments are intended to explain and not to limit the invention. It may be apparent that such embodiments may be practiced without these specific details.

[0052] Fig. 1 shows an example of a gas turbine 10 in a sectional view. The gas turbine 10 may include, in flow order, an inlet 12, a compressor or compressor section 14, a combustor section 16, and a turbine section 18, arranged generally in flow order and generally about and in the direction of a longitudinal or rotational axis 20. The gas turbine 10 may further include a shaft 22 rotatable about the rotational axis 20 and extending longitudinally through the gas turbine 10. The shaft 22 may driveably connect the turbine section 18 to the compressor section 14.

[0053] During operation of the gas turbine 10, the air 24 taken in through the air inlet 12 is compressed by the compressor section 14 and delivered to the combustion section or combustor section 16. The combustor section 16 may include a combustor plenum 26, one or more combustion chambers 28, and at least one burner 30 attached to each combustion chamber 28. The combustion chambers 28 and the burners 30 may be located within the combustor plenum 26. The compressed air flowing through the compressor 14 may enter a diffuser 32 and may be expelled from the diffuser 32 into the combustor plenum 26, from where a portion of the air may enter the combustor 30 and be mixed with a gaseous or liquid fuel. The air / fuel mixture is then combusted, with the combustion gas 34 or working gas from the combustion being passed through the combustion chamber 28 via a transition line 17 to the turbine section 18.

[0054] This exemplary gas turbine 10 may include a tubular combustor section assembly 16 formed by an annular array of combustor sleeves 19, each containing the burner 30 and the combustion chamber 28. The transition conduit 17 may include a generally circular inlet connected to the combustion chamber 28 and an outlet in the form of a ring segment. An annular array of transition conduit outlets may form an annular space for directing the combustion gases to the turbine 18.

[0055] The turbine section 18 may include a number of blade-supporting disks 36. The shaft includes the compressor disks, a drum (beneath the combustor section), and the turbine disks, all held together by a center anchor bolt and many fitting bolts connecting the disks. In the present example, two disks 36 are shown, each supporting an annular array of turbine blades 38. However, the number of blade-supporting disks could vary, i.e., only one disk or more than two disks. Additionally, between the rows of annular arrays of turbine blades 38, guide vanes 40 may be arranged, which are attached to a stator 42 of the gas turbine 10. Between the exit of the combustion chamber 28 and the leading turbine blades 38, inlet guide vanes 44 may be provided and direct the flow of the working gas onto the turbine blades 38.

[0056] The combustion gas from the combustion chamber 28 enters the turbine section 18 and drives the turbine blades 38, which in turn rotate the shaft 22. The guide vanes 40, 44 serve to optimize the angle of the combustion or working gas on the turbine blades 38.

[0057] The turbine section 18 drives the compressor section 14. The compressor section 14 includes rotating and non-rotating airfoils, specifically an axial array of guide vane rows 46 and rotor blade rows 48. The rotor blade rows 48 may comprise an impeller supporting an annular array of blades. The compressor section 14 may further include a casing 50 surrounding the rotor rows and supporting the guide vane rows 48. The guide vane rows may include an annular array of radially extending vanes mounted on the casing 50. The vanes are arranged to present the gas flow at an optimal angle for the blades at a given operating point of the turbine.Some of the vane rows may have variable vanes, where the angle of the vanes relative to their own longitudinal axis can be adjusted according to the airflow characteristics that may occur under various turbine operating conditions. The casing 50 may define a radially outer surface 52 of the passage 56 of the compressor 14. A radially inner surface 54 of the passage 56 may be at least partially defined by a rotor drum 53 of the rotor, which may be partially defined by the annular array of blades 48.

[0058] The present technique is described with respect to the above exemplary gas turbine, which has a single shaft or pulley connecting a single, multi-stage compressor and a single, single- or multi-stage turbine. However, it should be recognized that the present technique is equally applicable to two- or three-shaft gas turbines, which may be used for industrial, aviation, or marine applications.

[0059] The terms upstream and downstream refer to the flow direction of the air flow and / or working gas flow through the gas turbine, unless otherwise stated. The terms forward and reverse refer to the general flow of gas through the gas turbine. The terms axial, radial, and circumferential are used with respect to the rotational axis 20 of the gas turbine.

[0060] Fig. 2 schematically illustrates an example of a turbomachinery assembly. The assembly may include the turbine blades 38 disposed on the impeller 36. The turbine blade 38 may include a platform 100, an airfoil 200, and a root 300. The blade 38 may be attached or secured to the disk 36 via the root 300. According to the present technique, at least one, and preferably several or all, of the blades 38 include a fillet portion (although in Fig. 2 is not shown).

[0061] The following is a blade 1 according to the present technique with respect to the Fig. 4A and Fig. 2 compared to Fig. 3 has been declared. Fig. 3 illustrates a conventional blade 38' for comparison with the blade 1 of the present technique.

[0062] The bucket 1 includes a platform 100 and an airfoil 200 extending from the platform 100. The platform 100 may include a top surface 101 and a bottom surface 110. The airfoil 200 may extend from the top surface 101 of the platform 100. The top surface 101 extends in the circumferential direction. Similarly, the bottom surface 110 extends in the circumferential direction. The airfoil 200 extends radially outward from the top surface 101 of the platform 100.

[0063] The airfoil 200 includes a pressure surface 202 (also referred to as a pressure side or concave surface / side) and a suction surface 204 (also referred to as a suction side or convex surface / side). The pressure surface 202 and the suction surface 204 meet at a leading edge 206 and a trailing edge 208 of the airfoil 200.

[0064] The platform 100 includes: a pressure side 102 disposed toward the pressure surface 202 of the airfoil 200, a suction side 104 disposed toward the suction surface 204 of the airfoil 200, a leading edge side 106 disposed toward the leading edge 206 of the airfoil 200, and a trailing edge side 108 disposed toward the trailing edge 208 of the airfoil 200.

[0065] The pressure side 102 of the platform 100 may include a portion 101p (hereinafter also referred to as the pressure-side portion 101p) of the top surface 100 and a pressure-side side surface 103. The pressure-side side surface 103 may be arranged substantially perpendicularly with respect to the top surface 101 of the platform 100. The pressure-side side surface 103 may extend from the top surface 101 of the platform 100 in a direction opposite to a direction in which the airfoil 200 extends from the top surface 101 of the platform 100.

[0066] The pressure-side side surface 103 may be arranged generally radially when the blade 1 is arranged on the impeller 36 of the turbine 10. The pressure-side section 101p of the upper surface 101 of the platform 100 may be understood as a region of the upper surface 101 of the platform 100 that is arranged between the pressure surface 202 of the airfoil 200 and the pressure-side side surface 103 of the platform 100.

[0067] The suction side 104 of the platform 100 may include a portion 101s (hereinafter also referred to as the suction-side portion 101s) of the top surface 101 and a suction-side side surface 105. The suction-side side surface 105 may be arranged substantially perpendicular to the top surface 101 of the platform 100. The suction-side side surface 105 may extend from the top surface 101 of the platform 100 in a direction opposite the direction in which the airfoil 200 extends from the top surface 101 of the platform 100.

[0068] The top side 101 of the platform 100 contains the pressure side section 101p and the suction side section 101s.

[0069] The suction-side side surface 105 may be arranged generally radially when the blade 1 is arranged on the impeller 36 of the turbine 10. The suction-side section 104 of the upper surface 101 of the platform 100 may be understood as a region of the upper surface 101 of the platform 100 that is arranged between the suction surface 204 of the airfoil 200 and the suction-side side surface 105 of the platform 100.

[0070] The suction-side side surface 105 and the pressure-side side surface 103 of the platform 100 may be opposite side surfaces of the platform 100 that face away from each other. The suction-side side surface 105 and the pressure-side side surface 103 of the platform 100 may be substantially parallel (moderate skew angles are common) to the (in Fig. 1) axis 20 and / or perpendicular to the circumferential direction.

[0071] In the blade 1, at least a portion of an edge between the suction-side side surface 105 and the upper surface 101 of the platform 100 includes a groove portion 9. In particular, in the blade 1, at least a portion of an edge between the suction-side side surface 105 and the suction-side portion 101s of the upper surface 101 of the platform 100 includes the groove portion 9.

[0072] Compared to the Fig. 3, according to the present technique, the groove portion 9 is provided in the blade 1 as shown in Fig. 4A is shown.

[0073] The groove section 9 can be understood as a transition edge region between two surfaces, ie between at least a section of the suction-side side surface 105 and at least a section of the upper side 101 of the platform 100 of the blade 1. The groove section 9 can be understood as an inclined surface which lies as a transition region between at least a section or preferably only a section of the suction-side side surface 105 and at least a section or preferably only a section of the upper side 101 of the platform 100 of the blade 1.

[0074] The groove portion 9 may extend longitudinally, ie, it may have an elongated shape. The longitudinal axis (not shown) of the groove portion 9 may be aligned with a direction, ie, extend along a direction or be parallel to a direction extending from the leading edge side 106 of the platform 100 toward the trailing edge side 108 of the platform 100.

[0075] The groove section 9 can extend along an entire length of the suction-side side surface 105 of the platform 100 of the blade 1.

[0076] Alternatively, the grooved portion 9 may extend only along a portion of the entire length of the suction-side side surface 105 of the platform 100 of the blade 1. Consequently, the grooved portion 9 may be limited in one portion (e.g., the first portion) of the edge between the suction-side side surface 105 and the upper surface 101 of the platform 1, while another portion or portions (e.g., the second portion or portions) of the edge between the suction-side side surface 105 and the upper surface 101 of the platform may not be grooved. Consequently, the suction-side side surface 105 may be continuous with or adjacent to the upper surface 101 of the platform 100 in the second portion or portions. If there are multiple non-grooved portions, i.e., second portions, the first portion may be arranged between the two second portions.

[0077] The groove section 9 can have a (in Fig. 12B) upper edge 9a of the groove section 9 and a (in Fig. 12A). The upper edge 9a and the lower edge 9b of the groove portion 9 may be aligned in one direction, i.e., they may extend along a direction or be parallel to a direction extending from the leading edge side 106 of the platform 100 toward the trailing edge side 108 of the platform 100. The upper edge 9a and the lower edge 9b of the groove portion 9 may be radially spaced apart. The upper edge 9a and / or the lower edge 9b of the groove portion 9 may be rounded.

[0078] Fig. Figure 4B schematically illustrates the operation of the blade 1 of the present technique, e.g., the blade 1 according to Fig. 4A, for cooling a transition region where the airfoil 200 meets the platform 100 of the blade 1, and / or for cooling a region(s) of the platform 100, e.g., a portion of the suction-side section 101s of the top surface 101 adjacent to the transition region, in accordance with the present technique.

[0079] As in Fig. 4B, when the blade 1 of the present technique is installed in the exemplary turbine 10 and when the turbine 10 is operated, the blades 1 are rotated in the direction indicated by the reference numeral 8 in Fig. 4B marked arrow. As a result of the flow field, any cooling air 5 present adjacent to the suction-side surface 105 of the platform 100 tends to move towards the suction surface 204, with the groove portion 9 facilitating this movement of the cooling air 5 due to the inclined surface of the groove portion 9 compared to a blade, e.g., the blade shown in Fig. 3, which does not include the groove portion 9 of the present technique.

[0080] In general, the airflow within an axial gas turbine can be divided into a main hot gas airflow and a secondary hot gas airflow. The main hot gas airflow flows axially through the sections of the gas turbine. With regard to the present invention, it flows through the rows of blades in the turbine section. That is, due to the slower laminar flow of the gas at the walls of the blades, a secondary airflow is generated that is mainly perpendicular to the main airflow. Examples of secondary airflow are horseshoe vortex, tip vortex, and through vortex. The through vortex is generated on the suction side in the transition region to the platform. The through vortex is fed by air from the laminar layer moving from the pressure side to the suction side and is sucked through the suction side of the blade and flows on the suction side of the blade, which prevents efficient film cooling on the suction side of the blades.This reduces the cooling efficiency on the suction side and requires additional measures to cool the suction side of the blades. The grooved section is provided to improve cooling.

[0081] Due to the internal design of the blade rows, there is cooling air / leakage in the gap between the platform's side surfaces. This air tends to stay in the gap and follows the lower pressure at the trailing edge of the axial platform. The cooling / leakage in the gap can be caused by the upward flow of air from the cavity between the blade rows, the upward flow between the platforms from the roots, and / or the air provided by the cooling holes within the platforms.

[0082] By providing the groove section 9, the cooling air 5 is entrained by the hot gas secondary air, whereby due to the increase in cross-sectional area in the gap, the opposing pressure is increased and the cooling air within the gap is forced out of the gap and directed into the transition region and / or the adjacent regions of the blade.

[0083] The pressure for the leakage / cooling air flowing between the blades increases due to the increase in the cross-sectional area in the groove section 9. This forces the air flowing within the gap between the blades into the transition area and / or adjacent areas, i.e., the leakage / cooling air is deflected into the transition area and / or adjacent areas to increase the cooling effect at these critical sections of the blade. Due to the improved cooling, the durability of the blade is greatly increased.

[0084] The cooling air 5 used to cool the transition region and / or the adjacent regions may have previously been used to cool another portion of the blade (e.g., the platform) or may have been used for another purpose, e.g., as the seal purge air for a seal disposed on the impeller 36 between two adjacent blades of the gas turbine.

[0085] The groove section 9 can promote or direct the flow of the cooling air 5 from one side of the suction-side side surface 105 of the platform 100 over the suction-side section 101s of the upper side 101 of the platform 100 towards the suction surface 204 of the airfoil 200 and in particular towards a section of the suction surface 204 that is present near the trailing edge 208 of the airfoil 200, optionally including the trailing edge 208 of the airfoil 200.

[0086] Alternatively or additionally, the grooved section 9 can promote or direct the flow of cooling air over the suction-side section 101s of the upper side 101 toward the trailing edge 208 of the blade 200. As a result, the transition region in which the blade 200 meets the platform 100 of the blade 1 and / or at least a portion of the suction-side section 101s of the upper side 101 adjacent to the transition region is cooled.

[0087] The transition area where the blade 200 meets the platform 100 of the blade 1 may optionally include a fillet 350 (as in Fig. 2 and also in Fig. 9B).

[0088] The fillet 350 may be arranged around at least a portion of the airfoil 200. The fillet 350 may be arranged in or at a region where the airfoil 200 is connected to the platform 100. At least a portion of the fillet 350 may be arranged between the airfoil 200 and the fillet section 9 when viewed perpendicular to the chord of the airfoil. In other words, at least a portion of the fillet 350 may be arranged when viewed in a direction perpendicular to (in Fig. 12A) chord C of the airfoil 200 may be arranged directly between the suction surface 204 of the airfoil 200 and the groove portion 9.

[0089] As described above, the chord length C is preferably measured at a height of 5%-10% of the height of the airfoil or blade 1 above the platform surface. The chord length C can be measured on a flat cross-sectional surface of the airfoil parallel to the rotation axis. It can be measured from the leading edge to the trailing edge, specifically by measuring the maximum distance between the leading edge and the trailing edge. The measurement points are located on the lines that are at right angles to the suction-side surface or pressure-side surface.

[0090] The groove section 9 can promote or guide the flow of cooling air 5 over the suction-side section 101s of the upper side 101 toward the groove 350, in particular toward the section of the groove 350 located between the blade 200 and the groove section 9. As a result, the groove 350 of the blade 1 and / or at least a section of the suction-side section 101s of the upper side 101 adjacent to the groove 1 is cooled.

[0091] In the following, some other aspects of the blade 1 of the present technique are discussed with respect to the Fig. 5 and Fig. 6 in combination with the Fig. 2 and Fig. 4A explained.

[0092] The leading edge side 106 of the platform 100 may include a leading edge side surface 107. The leading edge side surface 107 may be arranged substantially perpendicularly with respect to the top surface 101 of the platform 100 and may extend from the top surface 101 of the platform 100 in a direction opposite to the direction in which the airfoil 200 extends from the top surface 101 of the platform 100. The leading edge side surface 107 may be arranged generally radially when the blade 1 is arranged on the impeller 36 of the turbine. The leading edge side surface 107 may be generally perpendicular to (in Fig. 1) when the blade 1 is mounted on the turbine impeller 36. The leading edge side surface 107 can be arranged between the suction-side side surface 105 and the pressure-side side surface 103 of the platform 100.

[0093] As in the Fig. 4A, Fig. 5 and Fig. 6, the groove portion 9 may be spaced from the leading edge side surface 107 of the platform 100.

[0094] As in the Fig. 4A, Fig. 5 and Fig. 6, the trailing edge side 108 of the platform 100 may include a trailing edge side surface 109. The trailing edge side surface 109 may be disposed substantially perpendicularly with respect to the top surface 101 of the platform 100 and may extend from the top surface 101 of the platform 100 in a direction opposite the direction in which the airfoil 200 extends from the top surface 101 of the platform 100.

[0095] The trailing edge side surface 109 may be arranged generally radially when the blade 1 is arranged on the impeller 36 of the turbine. The trailing edge side surface 109 may be arranged generally perpendicular to the (in Fig. 1) when the blade 1 is mounted on the turbine impeller 36. The trailing edge side surface 109 can be arranged between the suction-side side surface 105 and the pressure-side side surface 103 of the platform 100.

[0096] The leading edge side surface 107 and the trailing edge side surface 109 of the platform 100 may be opposite side surfaces of the platform 100 that face away from each other. When the blade 1 is installed in the gas turbine, the leading edge side surface 107 and the trailing edge side surface 109 of the platform 100 may be axially spaced apart.

[0097] As in the Fig. 4A and Fig. 6, the groove portion 9 may be spaced from the trailing edge side surface 107.

[0098] Alternatively, as in Fig. 5, the groove portion 9 may be continuous with the trailing edge side surface 109, that is, the groove portion 9 may start at the trailing edge side surface 109 and may extend towards the leading edge side surface 107 of the platform 100.

[0099] The following are Fig. 6 and the Fig. 12A, Fig. 12B and Fig. 12C explains some exemplary dimensions of the blade 1.

[0100] As in Fig. 12A, in the blade 1, a ratio (C / L) of a chord length C of the airfoil 200 and a length L of the groove portion 9 may be greater than or equal to 1.05 and less than or equal to 8.1. Simply put, the ratio may be between 1.05 and 8.1. The length L of the groove portion 9 may be measured parallel to a chord of the airfoil 200.

[0101] A chord can be understood as an imaginary straight line connecting the leading edge 206 and the trailing edge 208 of the airfoil 200. The chord length C can be a distance between the trailing edge 208 and a point where the chord C intersects the leading edge 206.

[0102] The above-mentioned ratio (C / L) is for each of the Fig. 4A or in Fig. 4 or in Fig. 6 illustrated embodiments of the blade 1 are applicable.

[0103] As in Fig. 12A, in the bucket 1, a slope (a / b) of the groove portion 9 may be greater than or equal to 0.8 and less than or equal to 3, that is, the slope (a / b) of the groove portion 9 may be between 0.8 and 3. The distance 'A', which may be referred to as a horizontal distance or length of the groove portion 9, is measured substantially parallel to the trailing edge side edge of the platform 100, while 'B', which may be referred to as a vertical distance or length of the groove portion 9, is measured perpendicular to the trailing edge side edge of the platform 100 and to the top surface of the platform.

[0104] As in Fig. 12A, in the blade 1, a ratio (C / f) of a chord length C of the airfoil 200 and a length f of a first non-grooved edge portion 99 (non-grooved leading edge portion 99) of the suction side surface 105 of the platform 100 may be greater than or equal to 1.03 and less than or equal to 5.9, that is, between 1.03 and 5.9.

[0105] The first non-grooved edge region 99 can be understood as a region of the edge between the suction-side side surface 105 and the top surface 101 of the platform 100, which, when viewed in a direction perpendicular to the chord C of the airfoil 200, is located laterally between the leading edge 206 of the airfoil 200 and the groove section 9. The lengths C, f can be measured parallel to the chord C of the airfoil 200.

[0106] The chord length C can be between 30 mm (millimeters) and 300 mm, preferably between 30 mm and 220 mm. The value of 'A', as in Fig. 12A can be between 0.5 mm and 12 mm.

[0107] For the embodiments of the blade 1 in which the groove portion 9 is spaced from the trailing edge side surface 107, as shown in the Fig. 4A, Fig. 6 and Fig. 12C, a distance 'h' of a non-scoured trailing edge portion 99' or a second non-scoured edge portion 99' of the suction side surface 105 of the platform 100 may be greater than or equal to 1 mm to 100 mm, preferably 10 mm and less than or equal to 15 mm.

[0108] The non-scoured trailing edge chord region 99' may be understood as a region of the edge between the suction-side side surface 105 and the top surface 101 of the platform 100, which, when viewed in a direction perpendicular to the chord C of the airfoil 200, is laterally located between the trailing edge 208 of the airfoil 200 and the scoop section 9. The lengths C, f may be measured parallel to the chord C of the airfoil 200.

[0109] It should be noted that all dimensions and ranges are exemplary and are not intended to limit the present technology. Dimensions and ranges other than those described above may be used in the present technology and are within the scope of the present technology unless otherwise specified.

[0110] With reference to Fig. 2 and Fig. 9B, another exemplary embodiment of the present technique is described below.

[0111] As in Fig. 2, the platform 100 may include a bottom surface 110 opposite the top surface 101 of the platform 100. The groove portion 9 may be separated from the bottom surface 110 by a portion 1051, as shown in Fig. 9B, the suction-side side surface 105. In other words, the groove portion 9 extends from the top side 101 of the platform 100, but does not extend to the bottom side 110 of the platform 100.

[0112] The bottom side 110 of the platform 100 can be understood as the surface of the platform 100 from which the root 300 of the blade 1 extends.

[0113] With reference to Fig. 6, another exemplary embodiment of the present technique is described below.

[0114] As in Fig. As shown in Figure 6, the blade 1 may include one or more cooling channels 400 formed in the platform 100. The cooling channels 400 may be completely embedded in the platform 100 at their side surfaces. At least one of the one or more cooling channels 400 may include an outlet 401 for cooling air. The outlet 401 may be arranged on the pressure-side side surface 103 of the platform 100 and / or on the suction-side side surface 105 of the platform 100.The one or more cooling channels 400 of the platform may be fluidly connected to the cooling channels (not shown) formed within the airfoil 200 and / or within the root 300 of the blade 1, thus allowing cooling air to flow from the root 300 of the blade 1 and / or from the airfoil 200 of the blade 1 into the one or more cooling channels 400 of the platform 100 and exit the platform 100 at the pressure side surface 103 of the platform 100 through the outlet 401.

[0115] In the case of the blade 1, a distance D2, which is indicated by the reference symbol D22 in Fig. 6, the distance of the outlet 401 from the leading edge side surface 107 of the leading edge side 106 of the platform 100 may be smaller than a distance D1 of the groove portion 9 from the leading edge side surface 107 of the leading edge side 106 of the platform 100. The distances D1, D2, D22 may be measured parallel to the chord C of the airfoil 200.

[0116] Optionally, in addition to the above, a difference (D1 - D22) between the distances D1, D22 may be smaller than the distance D22 of the outlet 401 from the leading edge side surface 107 of the leading edge side 106 of the platform 100. Simply put, the outlet 401 may be located closer to the groove portion 9 than to the leading edge side surface 107 of the leading edge side 106 of the platform 100. The distances D1, D22 may be measured parallel to the chord of the airfoil C of the airfoil.

[0117] In other words, a horizontal distance between the outlet 401 and the groove portion 9 measured perpendicular to the leading edge side surface 107 of the platform 100 may be smaller than a horizontal distance between the outlet 401 and the leading edge side surface 107 of the platform 100.

[0118] Alternatively, in the case of the blade 1, a distance D2, which is indicated by the reference symbol D21 in Fig. 6, the distance of the outlet 401 from the leading edge side surface 107 of the platform may be equal to or greater than the distance D1 of the groove portion 9 from the leading edge side surface 107 of the platform 100 and equal to or less than a sum (D1 + L) of the distance D1 of the groove portion 9 from the leading edge side surface 107 of the platform 100 and the length L of the groove portion 9. The length L of the groove portion 9 and the distances D1 and D21 may be measured parallel to the chord C of the airfoil 200.

[0119] The following is about the Fig. 9A and Fig. 9B an exemplary embodiment of a turbomachine arrangement, such as in Fig. 2, of the present technique, in which the blade 1, such as in one of the Fig. 4A, Fig. 5 and Fig. 6, is included in the present technique. For comparison and easy understanding, the Fig. 8A and Fig. 8B shows a conventional turbomachinery arrangement in which a conventional blade, e.g., the conventional blade 38', as in Fig. 3 is shown.

[0120] The turbomachinery arrangement according to the present technique as described by the Fig. 9A and Fig. 9B, which will also be referred to as the assembly, includes a plurality of blades which are attached to the (in the Fig. 1 and Fig. 2) impeller 36. The plurality of blades includes at least one (in the Fig. 10A and Fig. 11A). The at least one first blade 1a is a blade according to one of the above embodiments of the blade 1 presented above according to the first aspect of the present technique, e.g., any of the blades 1 of the present technique as illustrated by the examples according to the Fig. 4A, Fig. 5 and Fig. 6. A cooling air flow path (e.g. a Fig. The flow path for the cooling air 5 shown in Fig. 4B can be arranged adjacent to the suction-side side surface 105 of the first blade 1a.

[0121] The cooling air flow path may be partially defined by a turbomachine component other than the first blade 1a, or may be defined by the root 300 of the first blade 1a or by the suction-side surface 105 of the first blade 1a. The cooling air flow path may include a flow path for the cooling air 5 used to cool another portion of the gas turbine other than the first blade 1a, e.g., for cooling a blade adjacent to the first blade 1a, or used for another purpose, e.g., as the seal purge air for a seal between the first blade 1a and the blade adjacent to the first blade 1a, which is arranged on the impeller 36.

[0122] As in the Fig. 9A and Fig. 9B, at least one of the blades of the assembly has the groove portion 9 instead of a conventional edge E shown in the Fig. 8A and Fig. 8B is shown.

[0123] As in the Fig. 10A and Fig. 10B, in the arrangement, all the blades may be the first blades 1a, ie, the blade 1 with the groove portion 9 according to the present technique (although the groove portion 9 of one of the two blades of the arrangement is not shown), or one or more blades may be the first blades 1a, while others may be the Fig. 3. The cooling air 5a present between the blades of the assembly and / or the seal purge air 5a present between the blades of the assembly is guided through the groove section 9, as described above with respect to Fig. 4B has been described.

[0124] As in the Fig. 1A and Fig. 11B, in the arrangement, the plurality of blades may include at least one second blade 1b disposed adjacent to the at least one first blade 1a. The at least one second blade 1b may be the blade 1 including the groove portion 9 as disclosed above in the first aspect of the present technique, and may further include the one or more cooling channels 400 formed in the platform 100 and having the outlet 401 disposed on the pressure-side surface 103 of the platform 100, as discussed above.

[0125] Simply put, the second blade 1b is the same as the first blade 1a, but includes the one or more cooling channels 400 formed in the platform 100 and having the outlet 401 located on the pressure-side surface 103 of the platform 100. To further explain, it can be stated that the first blade 1a is the blade 1 having the groove portion 9 and may or may not further include the cooling channels 400 with the outlets 401, whereas the second blade 1b is the same as the blade 1 having the groove portion 9 and further includes the cooling channels 400 with the outlets 401.

[0126] The cooling air flow path may be arranged between the second blade 1b and the suction-side side surface 105 of the first blade 1a. The cooling air 5a present between the blades 1a, 1b of the assembly and / or the seal purge air 5a present between the blades 1a, 1b of the assembly and / or the cooling air 5b exiting from the outlet 401 of the second blade 1b is guided through the groove portion 9, as described above with respect to Fig. 4B. It can be stated that because the outlet 401 discharges the cooling air 5b toward the suction-side surface 105, the cooling air is guided more efficiently through the groove portion 9, as described above with respect to Fig. 4B has been described.

[0127] The following are the Fig. 4A, Fig. 5 and Fig. 6 and Fig. 7 and the Fig. 11A and Fig. 11B further exemplary embodiments of the arrangement are described.

[0128] In the arrangement, the plurality of blades may include at least a third blade 2, as in Fig. 7. The third blade 2 can be arranged adjacent to the at least one first blade 1a, ie, the blade 1 with the groove portion 9.

[0129] Simply put, the third blade 2 is a blade, e.g. one in Fig. 3, which includes one or more cooling channels 400' (similar to cooling channels 400) formed in the platform 100' (similar to platform 100') and having an outlet 401' (similar to outlet 400') located on the pressure-side surface 103' of the platform 100'. The third blade 2 may not include the groove portion 9.

[0130] The at least one third blade 2, as shown in the Fig. 7 and Fig. 11A and Fig. 11B, may include a platform 100' and an airfoil 200' extending from the platform 100'. The platform 100' may include a top surface, wherein the airfoil 200' may extend from the top surface of the platform 100'.

[0131] The airfoil 200' of the third blade 2 includes a pressure surface 202' and a suction surface 204'. The pressure surface 202' and the suction surface 204' meet at a leading edge 206' and a trailing edge 208' of the airfoil 200' of the third blade 2.

[0132] The platform 200' of the third blade 2 includes: a pressure side 102' arranged towards the pressure surface 202' of the airfoil 200', a suction side 104' arranged towards the suction surface 204' of the airfoil 200', a leading edge side 106' arranged towards the leading edge 206' of the airfoil 200', and a trailing edge side 108' arranged towards the trailing edge 208' of the airfoil 200'.

[0133] The pressure side 102' of the platform 100' may include a portion 101'p (hereinafter also referred to as the pressure-side portion 101'p) of the upper side and a pressure-side side surface 103'. The suction side 104' of the platform 100' may include a portion 101's (hereinafter also referred to as the suction-side portion 101's) of the upper side and a suction-side side surface 105'. The third blade 2 further comprises one or more cooling channels 400' formed in the platform 100' of the third blade 2, and wherein at least one of the one or more cooling channels 400' of the third blade 2 comprises an outlet 401' for the cooling air 5b, and wherein the outlet 401' is arranged on the pressure-side side surface 103' of the platform 100' of the third blade 2.

[0134] As further stated in Fig. 7, in the arrangement, a distance D2' of the outlet 401' from the leading edge side surface 107' of the third blade 2 may be smaller than the distance D1 (as shown in Fig. 6) of the groove portion 9 from the leading edge side surface 107 of the first blade 1a. The distances D2' and D1 can be measured parallel to the chords of the blades 200', 200 of the respective blades 2, 1.

[0135] Optionally, in addition to the above, a difference between the distances D1, D2' may be smaller than the distance D2' of the outlet 401' from the leading edge side surface 107' of the third blade 2. The distances D1, D2' may be measured parallel to the chords of the blades 200, 200' of the respective blades 1a, 2. Simply put, the outlet 401' may be arranged closer to the groove portion 9 than to the leading edge side surfaces 107, 107'. The distances D1, D2' may be measured parallel to the chords C of the blades 200, 200' of the respective blades.

[0136] It can be stated that, although Fig. 7 shows only one cooling channel 400' with the outlet 401', there may be several cooling channels 401, each having the outlet 401'.

[0137] In a further embodiment, the outlet 401' of at least one of the one or more cooling channels 400' of the third blade 2 can be positioned directly facing the groove section 9 of the first blade 1a - as shown in the Fig. 11A and Fig. 11B is shown.

[0138] As in Fig. 12B, in the arrangement, a distance G between a lower edge 9b of the groove portion 9 of the at least one first blade 1a and the pressure-side side surface 103, 103' of the blade 1, 1b, 2 arranged adjacent to the at least one first blade 1a may be equal to or greater than 0.5 times and equal to or less than 3 times a horizontal distance A between the lower edge 9b of the groove portion 9 and an upper edge 9a, ie, an edge or boundary of the groove portion 9 adjacent to the upper side 101 of the platform 100.

[0139] It can be stated that the above range is applicable whether the arrangement includes only the first blades 1a or the second blades 1b or includes the first blades 1a and the third blade 2.

[0140] Although the present technique has been described in detail with reference to specific embodiments, it should be recognized that the present technique is not limited to those precise embodiments. Rather, in view of the present disclosure describing exemplary modes for making inventive subject matter, many modifications and variations would suggest themselves to those skilled in the art without departing from the scope of the appended claims. The scope of the invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations which come within the meaning and range of equivalence of the claims are to be considered within their scope.

Claims

[1] Blade (1) for a gas turbine (10), the blade (1) comprising: - a platform (100) with a top surface (101); and - an airfoil (200) extending radially outward from the top surface (101) of the platform (100), the airfoil (200) comprising a pressure surface (202) and a suction surface (204) meeting at a leading edge (206) and a trailing edge (208); and wherein the platform (100) further comprises: a pressure side (102) arranged in the direction of the pressure surface (202) of the blade (200) and having a pressure-side side surface (103); a suction side (104) arranged in the direction of the suction surface (204) of the blade (200) and having a suction-side side surface (105); a leading edge side (106) disposed toward the leading edge (206) of the airfoil (200) and comprising a leading edge side surface (107); and a trailing edge side (108) disposed toward the trailing edge (208) of the airfoil (200); wherein at least a portion of an edge between the suction-side side surface (105) and the top side (101) of the platform (100) has a groove portion (9), wherein the blade (1) further comprises one or more cooling channels (400) embedded in the platform (100), wherein at least one of the one or more cooling channels (400) comprises an outlet (401) for the cooling air, and wherein the outlet (401) is arranged on the pressure-side side surface (103) of the platform (100); wherein a distance (D22) of the outlet (401) from the leading edge side surface (107) is smaller than a distance (D1) of the groove section (9) from the leading edge side surface (107), the distances (D1, D22) being measured parallel to a chord of the airfoil (200). [2] A bucket (1) according to claim 1, wherein the leading edge side (106) of the platform (100) comprises a leading edge side surface (107) and wherein the groove portion (9) is spaced from the leading edge side surface (107). [3] A bucket (1) according to claim 1 or 2, wherein the trailing edge side (108) of the platform (100) comprises a trailing edge side surface (109) and wherein the groove portion (9) is spaced from the trailing edge side surface (109). [4] A bucket (1) according to claim 1 or 2, wherein the trailing edge side (108) of the platform (100) comprises a trailing edge side surface (109) and wherein the groove portion (9) is continuous with the trailing edge side surface (109) or extends to the trailing edge side surface (109). [5] Shovel (1) according to one of claims 1 to 4, wherein a ratio (C / L) of a chord length (C) of the airfoil (200) and a length (L) of the groove portion (9) is greater than or equal to 1.05 and less than or equal to 8.1, wherein the lengths (C, L) are measured parallel to a chord of the airfoil (200); and / or wherein a slope (A / B) of the groove portion (9) is greater than or equal to 0.8 and less than or equal to 3; and / or wherein a ratio of a chord length (C) of the airfoil (200) and a length (f) of a first non-grooved edge region (99) is greater than or equal to 1.03 and less than or equal to 5.9, wherein the first non-grooved edge region (99) is a portion of the edge between the suction-side side surface (105) and the top surface (101) of the platform (100) and, when viewed in a direction perpendicular to the chord of the airfoil (200), is arranged laterally between a starting point of a chord of the airfoil (200) at the leading edge (206) of the airfoil (200) and the groove section (9), and wherein the lengths (C, f) are measured parallel to the chord of the airfoil (200). [6] Blade (1) according to one of claims 1 to 5, wherein the platform (100) comprises a lower surface (110) opposite the upper surface (101), and wherein the groove portion (9) is spaced from the lower surface (110) by a portion (1051) of the suction-side side surface (105). [7] A blade (1) according to any one of claims 1 to 6, further comprising a groove (350) arranged around at least a portion of the blade (200) in a region where the blade (200) is connected to the platform (100), and wherein at least a portion of the groove (350) is arranged between the blade (200) and the groove portion (9). [8] Blade (1) according to one of claims 1 to 7, wherein a difference between the distance (D22) of the outlet (401) from the leading edge side surface (107) and the distance (D1) of the groove portion (9) from the leading edge side surface (107) is smaller than the distance (D22) of the outlet (401) from the leading edge side surface (107). [9] A turbomachine assembly comprising a plurality of blades arranged on an impeller, wherein the plurality of blades comprises at least a first blade (1a), and wherein the at least one first blade (1a) is a blade (1) for a gas turbine (10) according to any one of claims 1 to 8; and wherein a cooling air flow path is arranged adjacent to the suction-side side surface (105) of the first blade (1a). [10] Turbomachine arrangement according to claim 9, wherein the plurality of blades comprise at least one second blade (1b) arranged adjacent to the at least one first blade (1a), and wherein the at least one second blade (1b) is a blade (1) according to any one of claims 1 to 8 and wherein the suction-side side surface (105) of the first blade (1a) faces the pressure-side side surface (103) of the second blade (1b); and wherein the cooling air flow path is arranged between the second blade (1b) and the suction-side side surface (105) of the first blade (1a). [11] A turbomachine assembly according to claim 9, wherein the plurality of blades comprises at least one third blade (2) disposed adjacent to the at least one first blade (1a); wherein the at least one third blade (2) comprises: - a platform (100') with a top; and - an airfoil (200') extending from the top of the platform (100'), the airfoil (200') having a pressure surface (202') and a suction surface (204') meeting at a leading edge (206') and a trailing edge (208'); and wherein the platform (100') further comprises: a pressure side (102') arranged in the direction of the pressure surface (202') of the airfoil (200') and comprising a pressure-side side surface (103'); a suction side (104') arranged in the direction of the suction surface (204') of the blade (200'); a leading edge side (106') arranged towards the leading edge (206') of the airfoil (200'); and a trailing edge side (108') arranged towards the trailing edge (208') of the airfoil (200'); and wherein the third blade (2) further comprises one or more cooling channels (400') formed in the platform (100') of the third blade (2), and wherein at least one of the one or more cooling channels (400') of the third blade (2) comprises an outlet (401') for cooling air, and wherein the outlet (401') is arranged on the pressure-side side surface (103') of the platform (100') of the third blade (2). [12] Turbomachine assembly according to claim 11, wherein the leading edge side (106) of the first blade (1a) comprises a leading edge side surface (107) and the leading edge side (106') of the third blade (2) comprises a leading edge side surface (107'); and wherein a distance (D2') of the outlet (401') from the leading edge side surface (107') of the third blade (2) is smaller than a distance (D1) of the groove portion (9) from the leading edge side surface (107) of the first blade (1a), the distances (D1, D2') being measured parallel to the chords of the blades (200, 200') of the respective blades; and / or wherein a distance (D2') of the outlet (401') from the leading edge side surface (107') of the third blade (2) is smaller than a distance (D1) of the groove portion (9) from the leading edge side surface (107) of the first blade (1a), and a difference between the distances (D1, D2') is smaller than the distance (D2') of the outlet (401') from the leading edge side surface (107') of the third blade (2), wherein the distances (D1, D2') are measured parallel to the chords of the blades (200, 200') of the respective blades; and / or wherein the outlet (401') of at least one of the cooling channels (400') of the third blade (2) is positioned directly facing the groove portion (9) of the first blade (1a). [13] Turbomachine arrangement according to one of claims 9 to 12, wherein a distance (G) between a lower edge (9b) of the groove portion (9) of the at least one first blade (1a) and the pressure-side side surface (103, 103') of the blade (1a, 1b, 2) arranged adjacent to the at least one first blade (1a) is equal to or greater than 0.5 times and equal to or less than 3 times a horizontal distance (A) between the lower edge (9b) of the groove portion (9) and an upper edge (9a) of the groove portion (9). [14] Gas turbine (10) comprising a turbomachine assembly, the turbomachine assembly being according to any one of claims 9 to 13.

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