Patent Application
20130327061
The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a bucket assembly for a turbomachine.
In a turbomachine, air in passed into an inlet of a compressor. The air is passed through various stages of the compressor to form a compressed airflow. A portion of the compressed airflow is passed to a combustion assembly and another portion of the compressed airflow is passed to a turbine portion and used for cooling. In the combustion assembly, the compressed airflow is mixed with fuel and combusted to form a high temperature gas stream and exhaust gases. The high temperature gas stream is channeled to the turbine portion via a transition piece. The transition piece guides the high temperature gas stream toward a hot gas path of the turbine portion. The high temperature gas stream expands through various stages of the turbine portion converting thermal energy to mechanical energy that rotates a turbine shaft. The turbine portion may be used in a variety of applications including providing power to a pump, an electrical generator, a vehicle, or the like.
According to one aspect of the exemplary embodiment, a turbomachine bucket assembly includes a rotor member including a body having a center portion and an outer edge portion joined by a web. The rotor member includes one or more cooling fluid conduits having a dimension, and an inlet arranged at the outer edge. A plurality of turbine blades are provided on the rotor member and mechanically linked to the outer edge. Each of the plurality of blades includes an internal cooling passage that is fluidly connected to the one or more cooling fluid conduits. A cooling fluid control element is provided at each of the one or more cooling fluid conduits. The cooling fluid control element is configured and disposed to adjust the dimension of the one or more cooling fluid conduits to alter fluid flow into the plurality of blades.
According to another aspect of the exemplary embodiment, a turbomachine includes a compressor portion, a turbine portion mechanically linked to the compressor portion, a combustor assembly fluidly connected to the compressor portion and the turbine portion, and a turbomachine bucket assembly arranged in the turbine portion. The turbomachine bucket assembly includes a rotor member having a body including a center portion and an outer edge portion joined by a web. The rotor member includes one or more cooling fluid conduits having a dimension, and an inlet arranged at the outer edge. A plurality of blades is provided on the rotor member and mechanically linked to the outer edge. Each of the plurality of blades includes an internal cooling passage that is fluidly connected to the one or more cooling fluid conduits. A cooling fluid control element is provided at each of the one or more cooling fluid conduits. The cooling fluid control element is configured and disposed to adjust the dimension of the one or more cooling fluid conduits to alter fluid flow into the plurality of blades.
According to yet another aspect of the exemplary embodiment, a method of cooling a turbomachine bucket assembly arranged within a turbomachine includes determining a desired temperature profile at the turbomachine bucket assembly, detecting an actual temperature profile at the turbomachine bucket assembly, comparing the desired temperature profile with the actual temperature of the cooling fluid, and signaling a cooling fluid control element provided on the bucket assembly to adjust a flow rate of the cooling fluid if the actual temperature profile differs from the desired temperature profile more than a desired amount.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
With reference to
Turbine portion 6 includes a plurality of turbine stages 20. In the exemplary embodiment shown, turbine stages 20 include a first stage 24, a second stage 25, and a third stage 26. While shown as including three stages, it should be understood that the number of stages may vary. First stage 24 includes a first nozzle assembly 30 having a first plurality of nozzles or vanes 32, and a first bucket assembly 34 having a first plurality of buckets or blades 36. Second stage 25 includes a second nozzle assembly 40 having a second plurality of nozzle or vanes 42, and a second bucket assembly 44 having a second plurality of buckets or blades 46. Third stage 26 includes a third nozzle assembly 50 having a third plurality of nozzles or vanes 52, and a third bucket assembly 54 having a third plurality of buckets or blades 56.
First bucket assembly 34 also includes a rotor member 66 that supports the first plurality of blades 36. Rotor member 66 includes a rotor body 68 having a center portion 70 and an outer edge portion 73 that are joined through a web 75. Rotor member 66 includes a cooling fluid conduit 78 that is positioned at outer edge portion 73 and fluidically connected to an internal cooling passage 80 provided on blade 36. It should be understood that rotor member 66 may include a single cooling fluid conduit 78 associated with each of the first plurality of blades 36 or may include multiple cooling fluid conduits 78 associated with respective ones of the first plurality of blades 36. In either case, cooling fluid conduit 78 includes an inlet 82 that is exposed to a wheel space 84 of turbine portion 6.
Second bucket assembly 44 includes a rotor member 86 that supports the second plurality of blades 46. Rotor member 86 includes a rotor body 88 having a center portion 90 and an outer edge portion 93 that are joined through a web 95. Rotor member 86 includes a cooling fluid conduit 98 that is arranged at outer edge portion 93 and fluidically connected to an internal cooling passage 100 provided on blade 46. Cooling fluid conduit 98 includes an inlet 102 that is exposed to wheel space 84 of turbine portion 6. Turbine portion 6 also includes a wheel member 104 arranged between rotor member 66 and rotor member 86. Wheel member 104 includes a sealing structure 107 that is configured and disposed to limit hot gases flowing along a hot gas path (not separately labeled) from entering wheel space 84. Sealing structure 107 is spaced from a plurality of shroud members 110 associated with each of the second plurality of vanes 42. Each shroud member 110 includes sealing elements 112 that cooperate with sealing structure 107 to limit hot gas ingestion to wheel space 84.
In accordance with one aspect of the exemplary embodiment illustrated in
Controller 140 signals active control element 135 to change a dimension of cooling fluid conduit 78 to adjust cooling fluid flow into one or more of the first plurality of blades 36. Controller 140 is also coupled to one or more sensors 150 arranged within turbomachine 2. Sensors 150 may include one or more of a micro-electromechanical system (MEMS) sensor, a piezoelectric sensor, a transducer, and the like. Sensors 150 provide input to controller 140 of one or more operating parameters of turbomachine 2. The one or more operating parameters may include a temperature profile of the cooling fluid passing into rotor member 66, wheelspace temperature, hot gas path temperature and the like. Controller 140 determines a desired temperature profile for the first plurality of blades 36 and, if conditioning is warranted, signals active control element 135 to establish a desired flow rate of cooling fluid into cooling flow conduit 78 as will be detailed more fully below.
A method of operating turbomachine 2 and, more specifically, controlling a temperature profile of the first plurality of blades 36 is indicated at 160 in
Controller 140 compares the DTP with the ATP in block 166. If the DTP is the same as or within a desired range, for example within 5%, of the ATP no action is taken as seen on block 168. If, however it is determined in block 168 that the DTP does not equal or fall within the desired range of the ATP, controller 140 signals active control element 135 to adjust the dimension of cooling fluid conduit 78 to control an amount of cooling fluid flowing into the first plurality of blades 36 to achieve the DTP as seen in block 170. Adjusting the dimension of cooling fluid conduit 78 includes both increasing the dimension of cooling flow conduit 78 to increase cooling fluid flow into the first plurality of blades 36 and decreasing the dimension of cooling fluid conduit 78 to reduce the amount of cooling fluid flow passing into the first plurality of blades 36 depending on the magnitude (positive or negative) of the difference between the ATP and the DTP.
At this point it should be understood that the exemplary embodiment provide a system and method for controlling fluid flow into a bucket assembly to maintain a desired temperature profile of a plurality of blades to protect turbomachine components. It should be understood that while shown and described as being formed as part a rotor member for one bucket assembly; each bucket assembly of the turbine portion may be provided with a similar cooling system. It should also be understood that the control element may be mounted directly into one or more of the cooling fluid conduits or provided as part of one or more fluid injectors mounted to the rotor wheel. Also, it should be appreciated that while various examples of passive control elements, active control elements, and sensors were described and claimed in connection with the exemplary embodiment, other types of passive control elements, active control elements and sensors may also be employed.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
