Patent Application
20150013406
The system and method described herein relates generally to wind turbine towers. More specifically, the system and method relates to the removal of dents from a wind turbine tower.
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
During operation of a wind turbine, the wind turbine is subjected to thrust due to the interaction of wind with the rotor blades of the wind turbine, and this thrust load is transferred to the tower. Loads on the tower are also imposed by the weight of the rotor, nacelle, generator and gearbox. The uptower components may weigh 50 to 100 tons or more. The tower must support the weight of these components, but also the additional thrust loads imposed by the wind. Accordingly, any undesired imperfections in the tower that could affect its load carrying capacity should be minimized or eliminated.
Wind turbine towers must be transported to the installation site and handled during tower assembly. Unfortunately, during transportation or handling dents can be formed in the tower. The size and location of the dent determines if it negatively affects the load carrying capacity of the tower. A very small, shallow dent, may have no appreciable effect on the tower. However, a larger and deeper dent will have to be repaired before the tower can be used. Dents greater than a predetermined size and/or depth can negatively affect the buckling strength of the tower. Accordingly, dents may have to be removed from a wind turbine tower before use, or the tower section will need to be replaced.
In an aspect of the present invention, a system for removing a dent from a wind turbine tower is provided. The system includes a measuring system configured for measuring a shape of the dent in at least two dimensions. A ram assembly is configured to be placed against the dent and an inside portion of the wind turbine tower. A control system is connected to both the ram assembly and the measuring system, and the control system is configured for controlling operation of the ram assembly based on data received from the measuring system. The measuring system monitors the shape of the dent during activation of the ram assembly.
In another aspect of the present invention, a system for removing a dent includes a measuring system configured for measuring a shape of the dent in at least two dimensions. The measuring system includes a two dimensional array of sensors. A ram assembly is configured to be placed against the dent and an inside portion of a structure. A control system is connected to both the ram assembly and the measuring system. The control system is configured for controlling operation of the ram assembly based on data received from the measuring system. The measuring system monitors the shape of the dent during activation of the ram assembly.
In yet another aspect of the present invention, a method for removing a dent from a wind turbine tower includes the steps of, measuring a shape of the dent in at least two dimensions, formulating a plan for removing the dent based on results of the measuring step, placing a ram assembly inside the wind turbine tower and in contact with the dent, activating the ram assembly while simultaneously measuring the shape of the dent, and controlling activation of the ram assembly based on the shape of the dent.
One or more specific aspects/embodiments of the present invention will be described below. In an effort to provide a concise description of these aspects/embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with machine-related, system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. Additionally, it should be understood that references to “one embodiment”, “one aspect” or “an embodiment” or “an aspect” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments or aspects that also incorporate the recited features.
The measuring system 120 communicates with a control system 130 via a wired or wireless link. The control system 130 formulates a plan for removing the dent based on the results of the scan (or measuring) from the measuring system 120. As shown, the control system 130 is connected to both the measuring system 120 and a ram assembly 140, and the control system 130 controls operation of the ram assembly 140 based on data received from the measuring system.
The ram assembly 140 includes pipe sections 141 and 142 and an actuating cylinder 143. The ram assembly is sized to fit within the wind turbine tower and pipe section 142 (and/or pipe section 141) may be exchanged for pipes of different lengths to accommodate wind turbine towers of various diameters. The end of pipe section 141 includes a pad 145 that may be sized and shaped to conform to the desired inner profile of tower 112. Likewise, the end of pipe section 142 also includes a pad 146 that is sized and shaped to conform to the inner profile of tower 112, to distribute the forces during a pushing operation. The ram assembly 140 may be hydraulically powered, pneumatically powered, electrically powered, magnetically powered or a mixture thereof.
In operation, the measuring system 120 measures a shape of the dent 110 in at least two dimensions. In some applications it may be desired to measure the dent in three dimensions. The results of the measuring step are then sent to the control system 130, and the control system 130 formulates a plan for removing the dent 110 based on the received data. The plan may include where to place the pad 145, or how far to push pipe 141. The ram assembly 140 is placed inside tower 112 and pad 145 is placed in contact with dent 110 and pad 146 is placed in contact with an opposing portion of the tower 112. The ram assembly 140 is then activated by control system 130 while the measuring system simultaneously measures and monitors the shape of the dent 110. As the dent 110 becomes smaller, the shape changes and this change is detected by measuring system 120. This data is communicated back to control system 130 so that the control system 130 prevents ram assembly 140 from over-pushing dent 110.
In the past, dents 110 can respond variably to pushing from ram assembly 140. Some dents will respond very slowly and other dents will respond very quickly. Slowly responding dents are not a problem, as pushing too little can be remedied by further activation of the ram assembly. However, a dent that suddenly changes from concave (radially inwardly projecting) to convex (radially outwardly projecting) is a problem, in that convex dents can be more complex to repair. Accordingly, it would be advantageous to avoid the creation of convex dents during the process of removing concave dents. The constant monitoring of measuring system 120 during a pushing operation reduces the likelihood of creating a convex dent. For example, as dent 110 is “pushed out” feedback from measuring system 120 to control system 130 enables control system to reduce the pushing force or travel of ram assembly 140. When the dent 110 reaches a predetermined shape, the ram assembly can be turned off by control system 130.
Generally, in terms of hardware architecture, as shown in
The processor 612 is a hardware device for executing software, particularly that stored in memory 614. The processor 612 can be any custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the control system 130, a semiconductor based microprocessor (in the form of a microchip or chip set), a macroprocessor, or generally any device for executing software instructions. Examples of suitable commercially available microprocessors are as follows: a PA-RISC series microprocessor from Hewlett-Packard Company, an 80×86 or Pentium series microprocessor from Intel Corporation, a PowerPC microprocessor from IBM, a Sparc microprocessor from Sun Microsystems, Inc, or a 68xxx series microprocessor from Motorola Corporation.
The memory 614 can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, etc.)) and nonvolatile memory elements (e.g., ROM, hard drive, tape, CDROM, etc.). Moreover, the memory 614 may incorporate electronic, magnetic, optical, and/or other types of storage media. Note that the memory 614 can have a distributed architecture, where various components are situated remote from one another, but can be accessed by the processor 612.
The software in memory 614 may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. In the example of
The Ram control system 610 is a source program, executable program (object code), script, or any other entity comprising a set of instructions to be performed. When a source program, then the program needs to be translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory 614, so as to operate properly in connection with the O/S 622. Furthermore, the Ram control system 610 can be written as (a) an object oriented programming language, which has classes of data and methods, or (b) a procedure programming language, which has routines, subroutines, and/or functions, for example but not limited to, C, C++, Pascal, Basic, Fortran, Cobol, Perl, Java, and Ada. In the currently contemplated best mode of practicing the invention, the Ram control system 610 controls operation of the ram assembly 140 in conjunction with data received from the measuring system 120, 220, 320.
The I/O devices 616 may include input devices, for example but not limited to, a keyboard, mouse, scanner, microphone, projector, etc. Furthermore, the I/O devices 616 may also include output devices, for example but not limited to, a printer, display, etc. Finally, the I/O devices 616 may further include devices that communicate both inputs and outputs, for instance but not limited to, a modulator/demodulator (modem; for accessing another device, system, or network), a radio frequency (RF) or other transceiver, a telephonic interface, a bridge, a router, an image projector, a laser, etc.
If the control system 130 is a PC, workstation, or the like, the software in the memory 614 may further include a basic input output system (BIOS) (omitted for simplicity). The BIOS is a set of essential software routines that initialize and test hardware at startup, start the O/S 622, and support the transfer of data among the hardware devices. The BIOS is stored in ROM so that the BIOS can be executed when the control system 130 is activated.
When the control system 130 is in operation, the processor 612 is configured to execute software stored within the memory 614, to communicate data to and from the memory 614, and to generally control operations of the control system 130 pursuant to the software. The Ram control system 610 and the O/S 622, in whole or in part, but typically the latter, are read by the processor 612, perhaps buffered within the processor 612, and then executed.
When the ram control system 610 is implemented in software, as is shown in
In an alternative embodiment, where the ram control system 610 is implemented in hardware, the ram control system 610 can be implemented with any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
