JP2014047782A - Turbine rotor blade platform cooling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling arrangement in a platform in a rotor blade or a sidewall in a stator blade, in a turbine of a combustion turbine engine.SOLUTION: The cooling arrangement may include: a cooling chamber configured to pass coolant from an inlet to an outlet; and a rib positioned within the cooling chamber. The rib may partially divide the cooling chamber to form a switchback. The rib may be canted with respect to the cooling chamber such that the switchback has an ever narrowing channel.

Description

  The present application relates generally to combustion turbine engines, which include all types of combustion turbine engines, such as those used in power generation and aircraft engines, unless otherwise specified herein. More specifically, but not by way of limitation, the present application relates to an apparatus, system, and / or method for cooling a platform region of a turbine rotor blade and a sidewall region of a turbine stator blade.

  A gas turbine engine typically includes a compressor, a combustor, and a turbine. Compressors and turbines typically include rows of airfoils or blades that are axially stacked in multiple stages. Each stage typically includes a fixed array of circumferentially spaced stator blades and a set of circumferentially spaced rotor blades that rotate about a central axis or shaft. During operation, the rotor blades in the compressor rotate around the shaft to compress the air flow. The compressed air is then used in a combustor to burn the feed fuel. The hot gas flow produced by the combustion process is expanded through the turbine, causing the rotor blades to rotate around the shaft to which the rotor blades are attached. In this way, the energy contained in the fuel is converted into the mechanical energy of the rotating shaft, which can be used, for example, to rotate a generator coil that generates electricity.

  With reference to FIGS. 1 and 2, a turbine rotor blade 100 generally includes an airfoil portion or airfoil 102 and a blade root portion or blade root 104. The airfoil 102 can be described as having a convex suction surface 105 and a concave pressure surface 106. The airfoil 102 can be further described as having a leading edge 107 that is a leading edge and a trailing edge 108 that is a trailing edge. The blade root 104 includes a structure (typically including a dovetail 109 as shown) for securing the blade 100 to the rotor shaft, a platform 110 from which the airfoil 102 extends, and a dovetail 109 and platform 110. Can be described as having a shank 112 that includes a structure between them.

  As shown, the platform 110 can be substantially planar. More specifically, the platform 110 may have a planar upper side 113, which may include a flat surface extending axially and circumferentially as shown in FIG. As shown in FIG. 2, the platform 110 can have a planar lower side 114, which can also include a flat surface that extends axially and circumferentially. The upper side 113 and the lower side 114 of the platform 110 can be formed such that each is substantially parallel to the other. As shown, the platform 110 typically has a thin radial profile, ie, there is a relatively short radial distance between the upper side 113 and the lower side 114 of the platform 110.

  In general, the platform 110 is used on the turbine rotor blade 100 to form the inner flow boundary of the hot gas passage section of the gas turbine. Platform 110 further provides structural support for airfoil 102. During operation, the rotational speed of the turbine induces a mechanical loading action that creates a high stress region along the platform 110, which ultimately becomes oxidized, creep, low cycle when coupled to high temperatures. Causes formation of defects during operation such as fatigue cracking and others. Of course, these defects adversely affect the useful life of the rotor blade 100. These harsh operating conditions, i.e. the exposure of hot gas passages to extreme temperatures and the mechanical loading associated with rotating blades, are durable and long lasting, which work well and are cost effective to manufacture. It should be understood that considerable challenges arise when designing the rotor blade platform 110 to be used.

  One common solution to improve the durability of the platform region 110 is to cool the platform region 110 with a flow of compressed air or other cooling medium during operation, and various these types of platform designs. It has been known. However, as those skilled in the art will appreciate, the platform region 110 thus presents several design challenges that make it difficult to cool. For the most part, this is a peripheral component in which the platform 110 resides away from the central core of the rotor blade, as described above, and is usually structurally stable but has a thin radial thickness. This is due to the cumbersome geometry of this region for reasons of its design.

  In order to circulate the cooling medium, the rotor blade 100 typically includes one or more hollows that extend radially through the core of the blade 100, including at least through the blade root 104 and the airfoil 102. A cooling passage 116 (see FIGS. 3, 4, 5, and 9) is included. As will be described in more detail below, such cooling passages 116 can be formed with serpentine passages that wind through the central region of the blade 100 to increase heat exchange, although other configurations are possible. Is also possible. During operation, the cooling medium can flow into the central cooling passage through one or more inlets 117 formed in the inward portion of the blade root 104. The cooling medium circulates through the blade 100 and through an outlet (not shown) formed on the airfoil and / or through one or more outlets (not shown) formed in the blade root 104. Can be spilled through. The cooling medium can be pressurized and can include, for example, pressurized air, pressurized air mixed with water, steam, and the like. In many cases, the cooling medium is compressed air diverted from the engine compressor, although other sources are possible. As discussed in more detail below, these cooling passages typically include a high pressure cooling medium region and a low pressure cooling medium region. The high pressure coolant region typically corresponds to the upstream portion of the cooling passage having a higher coolant pressure, while the low pressure coolant region corresponds to the downstream portion having a relatively low coolant pressure.

  In some cases, the cooling medium can be routed from the cooling passage 116 into a cavity 119 formed between the shank 112 of the adjacent rotor blade 100 and the platform 110. From there, the cooling medium can be used to cool the platform area 110 of the blade, and its conventional design is shown in FIG. This type of design typically draws air from one of the cooling passages 116 and uses that air to pressurize the cavity 119 formed between the shank 112 / platform 110. When pressurized, this cavity 119 then supplies a cooling medium to a cooling channel that extends through the platform 110. After traversing the platform 110, cooling air can exit the cavity through film cooling holes formed in the upper side 113 of the platform 110.

  However, it should be understood that this type of conventional design has several drawbacks. First, since the cooling circuit is only formed after two adjacent rotor blades 100 are assembled, the cooling circuit is not built into one part. This adds a great degree of difficulty and complexity to installation and pre-installation flow testing. A second drawback is that the integrity of the cavity 119 formed between adjacent rotor blades 100 depends on how well the perimeter of the cavity 119 is sealed. Inadequate sealing can result in inadequate platform cooling and / or wasted cooling air. A third drawback is the inherent risk that hot gas path gas may be drawn into the cavity 119 or the platform 110 itself. This can occur if the cavity 119 is not maintained at a sufficiently high pressure during operation. If the pressure in the cavity 119 falls below the pressure in the hot gas passage, hot gas is drawn into the shank cavity 119 or the platform 110 itself so that these components withstand exposure to hot gas passage conditions. If not designed, these components will be damaged.

4 and 5 show another type of conventional design for platform cooling. In this case, the cooling circuit is built in the rotor blade 100 and does not include the shank cavity 119, as shown. Cooling air is taken from one of the cooling passages 116 that extend through the core of the blade 100 and is routed backward through a cooling channel 120 formed in the platform 110 (ie, “platform cooling channel 120”). As indicated by some arrows, the cooling air flows through the platform cooling channel 120 and exits through an outlet in the rear edge 121 of the platform 110 or from an outlet disposed along the suction side edge 122. . (When describing or referring to the edge or face of the rectangular platform 110, the edge or face is mounted based on its position relative to the suction surface 105 and pressure surface 106 of the airfoil 102 and / or the blade 100, respectively. It should be noted that in some cases it can be accurately described based on the front and rear direction of the engine, so as will be understood by those skilled in the art, the platform is rearward as shown in FIGS. It may include an edge 121, a suction side edge 122, a forward edge 124, and a pressure side edge 126. Additionally, the suction side edge 122 and the pressure side edge 126 are also generally referred to as “slash surfaces”. The narrow cavities that are called and formed between adjacent rotor blades 100 when installed are " It can be called a rush surface cavity ".)
It should be understood that the conventional designs of FIGS. 4 and 5 have the advantage over the design of FIG. 3 in that they are not affected by variations in assembly or installation conditions. However, this type of conventional design has some limitations or drawbacks. First, as shown, only a single circuit is provided on each side of the airfoil 102, thus limiting the control over the amount of cooling air used at different locations within the platform 110. Exists. Secondly, this type of conventional design generally has a limited coverage area. The serpentine path of FIG. 5 is an improvement over the coverage area over FIG. 4, but there is a dead area in the platform 110 that remains uncooled. Third, to obtain good coverage with the complexly formed platform cooling channel 120, the manufacturing cost increases dramatically, especially when the cooling channel has a shape that requires a casting process to form. To do. Fourth, these conventional designs typically release the cooling medium into the hot gas path after use and before the cooling medium is completely exhausted, which adversely affects engine efficiency. Fifth, this type of conventional design is generally less flexible. That is, the channel 120 is formed as an integral part of the platform 110 and provides little or no opportunity to change its function or configuration as operating conditions change. Furthermore, these types of conventional designs are difficult to repair or modify.

  In some cases, the platform cooling passage is configured in a switchback configuration. An example of such a design is shown in FIG. As shown, the switchback design includes a cooling chamber 130 that includes an inlet 132 and an outlet 134 and ribs 135 that divide the chamber 130 such that the cooling medium is forced to travel a detour route before reaching the outlet 134. Can be included. Thus, the cooling medium is exposed throughout the cooling chamber 130 so that the surrounding area can be convectively cooled. One disadvantage of this type of switchback is that the downstream section receives less cooling than the upstream section because the cooling medium absorbs heat as it moves through the switchback, which results in uneven cooling and component damage across the platform. This results in the generation of hot spots. It will be further appreciated that the above-described problems with rotor blade platform cooling are applicable to the sidewall regions within the turbine stator blades.

  As a result, conventional designs of rotor blade platform and stator blade sidewall cooling configurations lack one or more critical areas. An improved device, system, and / or that effectively and efficiently cools these blade areas while being cost-effective to build, flexible to applications, and durable Or there remains a need for a method.

US Patent No. 8011881

  In one exemplary embodiment, the present application describes a cooling device in a platform in a rotor blade in a turbine of a combustion turbine engine. The cooling device can include a cooling chamber configured to flow a cooling medium from the inlet to the outlet, and ribs disposed in the cooling chamber. The rib can partially divide the cooling chamber to form a switchback. The ribs can be tilted with respect to the cooling chamber so that the switchback has channels that continue to narrow.

  The present application further describes a cooling device in a sidewall in a stator blade in a turbine of a combustion turbine engine. The cooling device can include a cooling chamber configured to flow a cooling medium from the inlet to the outlet, and ribs disposed in the cooling chamber. The rib can partially divide the cooling chamber to form a switchback. The ribs can be tilted with respect to the cooling chamber so that the switchback has channels that continue to narrow.

  These and other features of the present invention will be more fully understood and appreciated by careful consideration of the following more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings. Let's go.

1 is a perspective view of an exemplary turbine rotor blade that may use embodiments of the present invention. FIG. 1 is a bottom view of a turbine rotor blade in which embodiments of the present invention may be used. FIG. 2 is a cross-sectional view of adjacent turbine rotor blades having a cooling system according to a conventional design. FIG. 1 is a plan view of a turbine rotor blade having a platform with internal cooling channels according to a conventional design. FIG. FIG. 6 is a plan view of a turbine rotor blade having a platform with internal cooling channels according to an alternative conventional design. 1 is a plan view with a partial cross-sectional view of a turbine rotor blade having a platform with an internal cooling channel having a switchback configuration according to a conventional design. FIG. 2 is a partial cross-sectional view of the upper portion of a turbine rotor blade platform having a cooling configuration according to an exemplary embodiment of the present invention. FIG. 8 is a side sectional view taken along line 8-8 in FIG. FIG. 6 is a plan view with a partial cross-sectional view of a platform of a turbine rotor blade having a cooling configuration according to an alternative embodiment of the present invention. FIG. 6 is a plan view with a partial cross-sectional view of a platform of a turbine rotor blade having a cooling configuration according to an alternative embodiment of the present invention. FIG. 6 is a plan view with a partial cross-sectional view of a platform of a turbine rotor blade having a cooling configuration according to an alternative embodiment of the present invention. FIG. 6 is a graph showing “Flow Parameters” versus “Total Flow Distance Through Switchback” according to experimental data relating to an embodiment of the present invention. FIG. 6 is a side view of a turbine stator blade showing the arrangement of a cooling arrangement according to an alternative embodiment of the present invention. FIG. 6 is a plan view with a partial cross-sectional view of a sidewall of a turbine stator blade having a cooling configuration according to an alternative embodiment of the present invention.

  As discussed above, various conventional designs of internal cooling passages 116 are somewhat effective in cooling certain areas within the rotor blade 100. However, as those skilled in the art will appreciate, the platform area has proven to be more difficult. This is due at least in part to the messy geometry of the platform, ie, the narrow radial height of the platform and the manner in which the platform protrudes away from the core or main body of the rotor blade 100. Nevertheless, the cooling requirements of the platform 110 are quite large when there is extreme temperature exposure of the hot gas path and high mechanical loading. As noted above, conventional platform cooling designs are not effective because they cannot address the specific challenges of the region, are inefficient with respect to the use of these cooling media, and / or are expensive to produce. It will be further appreciated that the sidewalls of the stator blade present similar problems and disadvantages with conventional approaches that will be discussed in more detail in connection with FIGS.

  Some specific descriptive terms can be used to describe exemplary embodiments of the present application. The meaning of these terms shall include the following definitions. The terms “downstream” and “upstream” are terms that indicate a direction with respect to the flow of a working fluid through a turbine or, optionally, a cooling medium through a cooling passage. Thus, the term “downstream” means the direction of flow and the term “upstream” means the opposite direction of flow. The term “radial” refers to movement or position perpendicular to the axis. Often it is necessary to describe the parts at various radial positions with respect to this axis. In these cases, if the first component is closer to the axis than the second component, the first component is “inboard” or “radially inward” of the second component. Can be stated in this specification. On the other hand, if the first component is farther from the axis than the second component, the first component is “outboard” or “radially outward” of the second component. As described herein. The term “axial” refers to movement or position parallel to the axis. And the term “circumferential” refers to movement or position about an axis. Unless otherwise noted, when the terms “radial”, “axial”, or “circumferential” are used, they are used in reference to the central axis of the turbine engine.

  With reference now to FIGS. 7-11, several views of an exemplary embodiment of the present invention are provided. In particular, a rotor blade 100 having a platform cooling arrangement 130 according to a preferred embodiment of the present invention is shown. As shown, the rotor blade 100 includes a platform 110 that resides at the interface between the airfoil 102 and the blade root 104. The cooling chamber 130 can be formed in the platform 110. For example, as shown in FIG. 7, the cooling chamber 130 can be located near the front edge 124 of the platform 110. The cooling chamber 130 can include an inlet 132 and an outlet 134. The inlet 132 can be supplied with a cooling medium by various methods, such as through an internal cooling medium passage through the rotor blade 110 or through a shank cavity 119. During operation, the cooling medium is routed through the cooling chamber 130 and proceeds from the inlet 132 to the outlet 134. The rib 135 can be disposed in the cooling chamber 130. The ribs 135 can be configured to partially divide the cooling chamber 130 such that a serpentine passage or a switchback passage (hereinafter “switchback 131”) is formed. As discussed in more detail below, the ribs 135 can be inclined with respect to the cooling chamber 130. According to embodiments of the present invention, the rib 135 can be inclined at an angle such that the switchback 131 has a channel that continues to narrow.

  In one preferred embodiment, the narrowing channel of the present invention is a channel that narrows at a constant rate as the channel extends from the inlet 132 to the outlet 134 of the cooling chamber 130. In other preferred embodiments, as used herein, a channel that continues to narrow is defined as a channel that narrows at a constant rate along both the flank of ribs 135. More specifically, the switchback 131 can be described as having a path disposed on each flank of the rib 135. These paths can be referred to as the upstream path 138 (because it matches the side of the rib 135 where the inlet 132 is located) and the downstream path 139 (because it matches the side of the rib 135 where the outlet 134 is located). Further, it will be appreciated that between the upstream path 138 and the downstream path 139, the switchback 131 can be described as having a turning section 142. The turn section 142 can define a turn of about 180 °.

  The cooling chamber 130 may have a planar configuration that is aligned with and contained within the platform 110 or a particular region of the platform 110. As used herein, the “outboard profile” of the cooling chamber 130 refers to the profile seen from the outboard position of the platform 110, which profiles are shown in FIGS. 7 and 9-11. It will be understood that this is a perspective view shown in FIG. It will be appreciated that in certain embodiments, the cooling chamber 130 may be offset from a curved surface such as the platform 110 having an upper side 113 that includes an area of more pronounced curvature. In some embodiments, the outboard profile of the cooling chamber 130 can be a quadrilateral (ie, having four straight sides) outboard profile. The rib 135 as shown can be linear in construction. In some embodiments, the outboard profile of the cooling chamber 130 is a parallelogram. More specifically, the outboard profile of the cooling chamber 130 can be a square, diamond, or rectangular outboard profile.

  As more clearly shown in FIG. 8, the platform 110 includes a planar upper side 113. (Note that, as used herein, “planar” means in an approximately or substantially planar shape. For example, the platform is at a radial location of the rotor blade. One skilled in the art will appreciate that it can be configured to have a slightly curved and convex outer surface with a curvature corresponding to the circumference of the turbine. This type of platform shape is considered planar because the radius of curvature is large enough to give the platform a flat appearance.) The cooling chamber 130 is a planar ceiling 168 just inward of the upper side 113 of the platform 110 as well as the ceiling. A flat floor 169 that is radially offset from 168 can be included. The radial height of the cooling chamber 130 can be described as a radial offset between the ceiling 168 and the floor 169. As shown, in the preferred embodiment, the radial height of the cooling chamber 130 is substantially constant. Ribs 135 extend from floor 169 of cooling chamber 130 to ceiling 168.

  The quadrilateral profile of the cooling chamber 130 can be described as including a first pair and a second pair of opposing sides or edges, each pair having two edges of the quadrilateral facing each other across the cooling chamber 130. Part. The first pair of opposing edges includes a first edge 151 and a second edge 152, and the second pair of opposing edges includes a third edge 153 and a fourth edge 154.

  In certain preferred embodiments, the inlet 132 and outlet 134 are disposed along the first edge 151 of the cooling chamber 130 and between the inlet 132 and outlet 134 ribs 135 that separate the inlet 132 from the outlet 134. The first end 157 can be disposed. From the first end 157, the rib 135 extends toward the second edge 152 of the cooling chamber 130, but terminates before the second edge 152. That termination point will be referred to herein as the second end 158 of the rib 135. That is, the second end 158 of the rib 135 is offset by a distance from the second edge 152, thereby forming a turning section 142 that redirects the coolant flow toward the outlet 134. The described rib 135 is inclined with respect to the cooling chamber 135. As shown in FIG. 7, the inclination of the rib 135 can be relative to the longitudinal axis of the cooling chamber 130. In a preferred embodiment, the ribs 135 are sloped such that as the upstream path 138 extends from the inlet 132 to the second end 158 of the rib 135, the channel width of the upstream path 138 decreases at a linear rate. Further, the rib 135 is inclined such that the channel width of the downstream path 139 decreases at a linear rate as the downstream path 139 extends from the second end 158 of the rib 135 to the outlet 134. In a preferred embodiment, the channel width at the downstream end of upstream path 138 may be slightly larger than the channel width at the upstream end of downstream path 139. As the rib 135 extends from the first edge 151 toward the second edge 152, the distance between the rib 135 and the third edge 153 decreases, while the rib 135 and the fourth edge 154. It will be appreciated that the ribs 135 are inclined toward the third edge 153 such that the distance between them increases.

  The angle or slope of the rib 135 can be described by the relationship that the rib 135 maintains relative to the longitudinal axis of the cooling chamber 130. When the third edge 153 and the fourth edge 154 are parallel, the reference line extending through the midpoint between the third edge 153 and the fourth edge 154 is the cooling chamber. It will be appreciated that the vertical axis of 130 is shown as the vertical reference line 159 in FIG. In certain preferred embodiments, the angle 176 defined by the rib 135 by the longitudinal reference line 159 of the cooling chamber 130 is between 0 ° and 60 °. More preferably, the angle 176 defined between the rib 135 and the longitudinal reference line 159 of the cooling chamber 130 is between 0 ° and 30 °.

  As shown in FIG. 7, the coolant passage defined by the switchback 131 includes a) an inlet channel width 160 representing the channel width of the switchback 131 at the inlet 132, and b) the second end 158 of the rib 135 and the second channel 158. A channel width 161 before rotation representing the channel width of the switchback 131 between the third edge 153 and c) the channel of the switchback 131 between the second end 158 of the rib 135 and the fourth edge 154. A post-turn channel width 162 representing the width, and d) an exit channel width 163 representing the channel width of the switchback 131 passage at the outlet 134. The channel that continues to become narrower includes a configuration in which the inlet channel width 160 is larger than the pre-turn channel width 161, the pre-turn channel width 161 is larger than the post-turn channel width 162, and the post-turn channel width 162 is larger than the outlet channel width 163. As further shown in FIG. 7, between the pre-turn channel width 161 and the post-turn channel width 162, the switchback 131 includes a turn section 142, within the turn section 142, the turn section channel width 164 is a rib 135. Represents the channel width of the switchback 131 between the second end 158 and the second edge 152 of the cooling chamber 130. According to the embodiment of the present application, the channel that the switchback 131 continues to become narrower includes a configuration in which the turning section channel width 164 is smaller than the pre-turning channel width 161 and larger than the post-turning channel width 162. Channels that continue to narrow along both the flank of the rib 135 have a channel width of the switchback 131 that decreases at a constant linear rate between the inlet channel width 160 and the pre-turn channel width 161, and the post-turn channel width 162. It can be further described as including the channel width of the switchback 131 decreasing at a constant linear rate with the exit channel width 163.

  As mentioned, the cooling passages in the turbine blades can be supplied with a cooling medium in various ways. Typically, the cooling passage can receive the cooling medium through an internal passage that connects to the cooling medium source through the blade root or can be supplied with the cooling medium through a connection with the shank cavity. Unless otherwise stated, the application should not be limited to any particular method or configuration for delivering the cooling medium to the inlet 132 or removing the cooling medium from the outlet 134 of the cooling chamber 130.

  As described above in connection with some conventional cooling designs, turbine blades that are cooled by internal circulation of the cooling medium typically extend radially outward from the blade root and into the airfoil. It will be appreciated that an internal cooling passage 116 is included. Certain preferred embodiments of the present invention can be used in conjunction with conventional coolant passages to enhance or enable efficient active platform cooling, and that aspects of the present invention can be twisted. It will be further appreciated that, although discussed in connection with one general design, such as an internal cooling passage 116 having a particular configuration or a serpentine configuration, the aspects are not limited to that application. As shown, the serpentine passages of the internal cooling passages 116 are typically configured to allow a unidirectional flow of the cooling medium and also facilitate heat exchange between the cooling medium and the surrounding airfoil 102. Including features. During operation, a pressurized cooling medium, typically compressed air extracted from the compressor (although in embodiments of the present invention other types of cooling medium such as steam may be used) is formed through the blade root 104. The internal cooling passage 116 is supplied through the connected portion. The pressure pushes the cooling medium through the internal cooling passage 116, which convects heat away from the surrounding wall.

  It is understood that as the cooling medium travels through the cooling passage 116, the cooling medium loses pressure and the cooling medium in the upstream portion of the internal cooling passage 116 has a higher pressure than the cooling medium in the downstream portion. It will be. As will be discussed in more detail below, this pressure differential can be used to drive the cooling medium across or through the cooling passages formed in the platform. It will be appreciated that the present invention can be used with rotor blades 100 having different configurations of internal cooling passages and is not limited to internal cooling passages having a serpentine configuration. Thus, as used herein, the term “internal cooling passage” or “cooling passage” is used to describe any cooling medium that can circulate in the rotor blades. It is intended to include a passage or a hollow channel. As shown herein, the internal cooling passage 116 of the present invention extends at least to a substantially radial height of the platform 110 and includes at least one region of relatively higher coolant pressure (hereinafter “high pressure region”). (Region of high pressure) ", which may be an upstream section in the serpentine passage in some cases) and at least one region of relatively lower coolant pressure (hereinafter" low pressure region ( region of low pressure), which can be a downstream section in the serpentine passage for high pressure regions).

  As shown in FIGS. 9 and 10, the high pressure connector 171 can be configured to connect the inlet 132 to the high pressure coolant medium region of the internal cooling passage 116, and the low pressure connector 172 can connect the outlet 134 to the internal cooling passage 116. And can be configured to connect to the low pressure cooling medium region. During operation, the pressure difference between the high pressure region and the low pressure region forces the cooling medium through the cooling chamber 130. That is, the high pressure connector 171 extracts a portion of the cooling medium from the internal cooling passage 116, a portion of which is used in the cooling chamber 130 to remove heat from the platform 110 and then through the low pressure connector 172. Returned to the cooling passage 116, it can be further used to cool the rotor blades.

  In other cases, as shown in FIG. 11, the inlet 132 can be supplied with a cooling medium to the internal cooling channel 116 via a connector (such as a high pressure connector 171), while the outlet 134 is connected to the platform 110. Are in fluid communication with a plurality of film cooling ports or surface ports 175 formed on the surface. In one preferred embodiment, the surface port 175 is disposed along the pressure side slash surface 126 as shown. In other embodiments, the surface port 175 can be disposed on the suction side slash surface 122.

  The present application describes a two-pass serpentine or switchback coolant passage for use with a turbine rotor blade platform thereby including angled or inclined ribs that promote more evenly distributed cooling. Referring to FIG. 12, it will be appreciated that as the flow distance through the coolant passage increases, the inclined ribs produce a decrease in coolant flow cross-sectional area. Specifically, FIG. 12 provides a graphical representation of “Flow Parameters” versus “Total Flow Distance Through Switchback”. As shown, the “Cross sectional Flow Area” decreases linearly due to the inclined rim. The reduction of the coolant flow area increases the speed of the coolant, which increases the “heat transfer coefficient” of the coolant. This increase counteracts the loss of cooling effect due to the increase in “Coolant Temperature” that occurs when the cooling medium absorbs the heat that travels along the cooling medium path. This creates a nearly constant “heat transfer coefficient” as the coolant moves from one end of the coolant passage to the other, creating hot spots that promote more even cooling across the platform and accelerate component degradation. Prevent or prevent.

  More specifically, by angling the rib between the two paths of the switchback, the cross-sectional area constantly decreases as the cooling medium flows through the passage. Because the mass flow rate of the cooling medium is constant, the decreasing area must produce a faster rate. This results in an increase in HTC as the fluid travels through the serpentine, as the duct flow heat transfer coefficient is greatly affected by the fluid velocity. It will be appreciated that as the cooling medium travels along the switchback, the temperature increases and picks up heat from the rotor blades, which prevents the cooling medium from cooling the downstream portion of the normal cooling medium path. Let's go. However, in this application, the loss of this cooling medium effect due to temperature rise is offset (by increasing the heat transfer coefficient with increasing speed), so that a relatively constant heat transfer rate is cooled in contrast to decreasing speed. A method is described that is maintained along the length of the media. As will be appreciated by those skilled in the art, for low flow applications where the convective heat transfer coefficient is low, embodiments of the present application allow greater heat transfer with the same amount of flow. This may allow the use of a switchback core in certain applications where flow is slow due to flow restrictions. In other applications, changing from a constant cross-sectional core to the proposed design can use flow more efficiently, which can increase engine efficiency for a turbine engine, thus reducing flow. Another benefit is that, in some cases, turbulent airfoils that cause undesirably high friction losses in the serpentine core can be reduced. In addition, the total area of the entire two-path switchback can be unchanged, when the only modification is the rib slope, which increases the size of the coolant passage or without increasing the amount of coolant. Allows great cooling.

  Alternatively, the design features described above can be applied in a similar manner to the sidewall region of the stator rotor blade. FIG. 13 shows a side view of a turbine stator blade showing the arrangement of a cooling arrangement according to an alternative embodiment of the present invention.

  FIG. 14 shows a top view with a partial cross-sectional view of the sidewalls of a turbine stator blade 180 having a cooling configuration according to an alternative embodiment of the present invention. Stator blade 180 may include an airfoil 181 that projects inwardly from a fixture with a fixed structure around the turbine section of the combustion engine. At the inboard edge of the airfoil 181, the stator blade 180 can include a sidewall 184 that defines an inner radial edge of the working fluid flow path through the turbine. It will be appreciated that the sidewall 184 is similar in shape to the platform 110 of the rotor blade 100. The sidewall 184 can include a cooling chamber 130 having substantially the same features as previously discussed. As shown, the cooling chamber 130 of the sidewall 184 can have an inlet connector 185 in fluid communication with the inlet 132 of the cooling chamber 130 and an outlet connector 186 in fluid communication with the outlet 134 of the cooling chamber 130. Will be understood. The cooling chamber 130 of the sidewall 184 can have ribs 135 that are angled or inclined as discussed above, and the ribs 135 can provide an upstream path 138 and a downstream path 139 that continue to narrow.

  As those skilled in the art will appreciate, the many different features and configurations described above with respect to some exemplary embodiments may be further selectively applied to form other possible embodiments of the invention. it can. For the sake of brevity and in view of the ability of those skilled in the art, not all possible iterations are provided or discussed in detail, but all combinations encompassed by some of the appended claims or others And possible embodiments are intended to be part of this application. Moreover, from the above description of several exemplary embodiments of the invention, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes and modifications within the skill of the art are also intended to be covered by the appended claims. Moreover, the foregoing relates only to the described embodiments of the present application, and numerous changes and modifications herein without departing from the spirit and scope of the present application as defined by the appended claims and their equivalents. It should be clear that corrections can be made.

100 turbine rotor blade 102 rotor airfoil or airfoil 104 blade root 105 suction surface 106 pressure surface 107 leading edge 108 trailing edge 109 dovetail 110 platform 112 shank 113 platform upper side 114 platform lower side 116 internal cooling passage 117 inlet 119 cavity 120 platform cooling Channel 121 rear edge 122 suction side edge or slash face 124 front edge 126 pressure side edge or slash face 128 pressure side of platform 130 cooling chamber 131 switchback 132 inlet 134 outlet 135 rib 138 upstream path 139 downstream path 142 turning Section 151 First edge 152 Second edge 153 Third edge 154 Fourth edge 15 First end portion 158 Second end portion 159 Vertical axis reference line 160 Inlet channel width 161 Pre-turn channel width 162 Post-turn channel width 163 Outlet channel width 164 Turn section channel width 168 Ceiling 169 (cooling chamber) Floor 171 High pressure connector 172 Low pressure connector 175 Surface port 176 Angle 180 Stator blade 181 Stator airfoil or airfoil 184 Side wall 185 Inlet connector 186 Outlet connector

Claims (21)

A cooling device in one of a sidewall of a stator blade in a turbine of a combustion turbine engine and a platform in a rotor blade;
A cooling chamber configured to flow a cooling medium from the inlet to the outlet;
A rib disposed within the cooling chamber and partially dividing the cooling chamber to form a switchback;
A cooling device that tilts relative to the cooling chamber such that the switchback includes a channel in which the ribs continue to narrow. The cooling device of claim 1, wherein the channel that continues to narrow includes a channel that narrows at a constant rate as the channel extends from the inlet to the outlet of the cooling chamber. The cooling device of claim 1, wherein the channel that continues to narrow includes a channel that narrows at a constant rate along both flank of the rib. The switchback is disposed on a path disposed on each flank of the rib, that is, on an upstream path disposed on the flank of the rib corresponding to the inlet and on a flank of the rib corresponding to the outlet. Provided with a downstream path,
The cooling device of claim 3, wherein the switchback includes a turning section that defines a turn of about 180 ° between the upstream path and the downstream path. The cooling chamber comprises a first edge and a second edge, the second edge facing the first edge across the cooling chamber;
The rib is offset by a distance from the first end disposed on the first edge of the cooling chamber between the inlet and the outlet and the second edge of the cooling chamber. The cooling device according to claim 4, wherein the cooling device extends linearly between the second end portion. When the upstream path extends from the inlet to the second end of the rib, the channel width of the upstream path decreases at a linear rate, and the downstream path extends from the second end of the rib. The ribs are inclined such that when extending to the outlet, the channel width of the downstream path decreases at a linear rate;
The cooling device according to claim 5, wherein the channel width at the downstream end of the upstream path is slightly larger than the channel width at the upstream end of the downstream path. The cooling chamber comprises a planar configuration and a quadrilateral outer profile;
The cooling device according to claim 1, wherein the rib is linear. The quadrilateral comprises first and second pairs of opposing edges, each pair comprising two of the quadrilateral sides facing each other across the cooling chamber;
The first pair of opposing edges includes a first edge and a second edge; the second pair of opposing edges includes a third edge and a fourth edge;
The inlet and the outlet are disposed on the first edge, and a first end of the rib is disposed on the first edge between the inlet and the outlet. Item 8. The cooling device according to Item 7. From the first end, the rib extends toward the second edge, the rib terminates at the second end,
The second end of the rib is offset by a distance from the second edge;
The third edge is parallel to the fourth edge;
9. A cooling device according to claim 8, wherein the rib is inclined with respect to the longitudinal direction of the cooling chamber defined by an intermediate point defined between the third edge and the fourth edge. . As the rib extends from the first edge toward the second edge, the distance between the rib and the third edge decreases at a linear rate, while the rib and the second edge The cooling device according to claim 9, wherein the rib is inclined toward the third edge such that the distance to the edge of the line 4 increases at a linear rate. The cooling device of claim 10, wherein an angle defined between the rib and the direction of the longitudinal axis of the cooling chamber is between 0 ° and 30 °. The angle defined between the rib and the longitudinal axis of the cooling chamber is between 0 ° and 60 °;
The switchback is a) an inlet channel width representing the channel width of the switchback at the inlet; b) the channel of the switchback between the second end of the rib and the third edge. Pre-turn channel width representing width, c) post-turn channel width representing the channel width of the switchback between the second end of the rib and the fourth edge, and d) at the exit An exit channel width representing a channel width of the switchback passage;
The channel that continues to become narrower has a configuration in which the entrance width is larger than the pre-turn channel width, the pre-turn channel width is larger than the post-turn channel width, and the post-turn channel width is larger than the exit channel width. 10. The cooling device according to 10. Between the pre-turn channel width and the post-turn channel width, the switchback comprises a turn section, wherein the turn section channel width is between the second end of the rib and the cooling. Represents the channel width of the switchback between the second edge of the chamber;
The cooling device according to claim 12, wherein the channel that continues to narrow has a configuration in which the turning section channel width is smaller than the pre-turn channel width and larger than the post-turn channel width. The narrowing channel along both the flank of the rib,
The channel width of the switchback decreasing at a constant linear rate between the inlet channel width and the pre-turn channel width;
13. The cooling device of claim 12, including the channel width of the switchback that decreases at a constant linear rate between the post-turn channel width and the exit channel width. The cooling device according to claim 9, wherein the outer profile of the cooling chamber includes a parallelogram. 10. The cooling of claim 9, wherein one of the platform and the sidewall comprises a planar configuration, and the cooling chamber comprises a planar configuration that is aligned with and included in the planar configuration of one of the platform and the sidewall. apparatus. One of the platform and the side wall comprises a planar upper side;
The cooling chamber comprises a planar ceiling immediately inward of the upper surface and a planar floor radially offset from the ceiling;
The radial height of the cooling chamber includes the radial offset between the ceiling and the floor;
The cooling device according to claim 9, wherein a radial height of the cooling chamber is constant. A cooling device is disposed in the platform of the rotor blade;
The rotor blade includes an internal cooling passage formed in the rotor blade, the internal cooling passage extending from a junction with a cooling medium source at a blade root to the platform at a substantially radial height, The internal cooling passage includes a high pressure cooling medium region and a low pressure cooling medium region;
A high pressure connector connecting the inlet to the high pressure cooling medium region of the internal cooling passage;
The cooling device according to claim 9, further comprising a low-pressure connector that connects the outlet to the low-pressure cooling medium region of the internal cooling passage. A cooling device is disposed in the platform of the rotor blade;
The rotor blade includes an internal cooling passage formed in the rotor blade, the internal cooling passage extending from a junction of the blade root with a cooling medium source to the platform at a substantially radial height;
A connector connecting the inlet to the internal cooling passage;
The cooling device according to claim 9, further comprising a plurality of films for cooling a port in fluid communication with the outlet. A cooling device for a platform of rotor blades in a turbine of a combustion turbine engine,
A cooling chamber configured to flow a cooling medium from the inlet to the outlet;
A rib disposed within the cooling chamber and partially dividing the cooling chamber to form a switchback;
A cooling device that tilts relative to the cooling chamber such that the switchback includes a channel in which the ribs continue to narrow. A cooling device for sidewalls of a stator blade in a turbine of a combustion turbine engine,
A cooling chamber configured to flow a cooling medium from the inlet to the outlet;
A rib disposed within the cooling chamber and partially dividing the cooling chamber to form a switchback;
A cooling device that tilts relative to the cooling chamber such that the switchback includes a channel in which the ribs continue to narrow.