Abstract:
A method for inspecting a turbomachine is provided. The method includes the steps of, attaching a gimbal mount to the turbomachine, inserting a probe into the turbomachine through the gimbal mount, and adjusting a position of the probe via the gimbal mount. A removing step removes the probe from the turbomachine. An attaching step attaches a traverse actuator system to the gimbal mount. The traverse actuator system is connected to the gimbal mount through a pressure isolation system. A reinserting step is used to reinsert the probe back into the turbomachine. An inspecting step is used to inspect or test the turbomachine.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to turbomachine inspection and/or testing. More particularly, the subject matter relates to a system and method for inspecting and/or testing operating turbomachines. 
         [0002]    In a turbine system, such as a steam turbine system, fluid flow is directed to selected portions of the turbine system to enable production of mechanical energy. Parameters relating to the fluid flow in the system may be measured to evaluate efficiency and performance for a particular turbine design. For example, pressure may be tested at selected locations in the turbine system using pressure tap assemblies. In certain locations, space for installation of the pressure tap assembly is reduced, causing difficulties when attempting to properly seal the assembly in the component. Fluid leaks at the pressure tap assembly proximate the main flow path can disrupt fluid flow, lead to measurement errors and reduce the accuracy of turbine efficiency calculations. Pressure tap assemblies are fixed and are limited to readings at a single location. Therefore, samples are difficult, if not impossible, to obtain from multiple locations in the operating steam turbine. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    In an aspect of the present invention, a method for inspecting a turbomachine is provided. The method includes the steps of, attaching a gimbal mount to the turbomachine, inserting a probe into the turbomachine through the gimbal mount, and adjusting a position of the probe via the gimbal mount. A removing step removes the probe from the turbomachine. An attaching step attaches a traverse actuator system to the gimbal mount. The traverse actuator system is connected to the gimbal mount through a pressure isolation system. A reinserting step is used to reinsert the probe back into the turbomachine. An inspecting step is used to inspect or test the turbomachine. 
         [0004]    In another aspect of the present invention, a method for inspecting an operating turbomachine is provided. The method includes the step of attaching a gimbal mount to the turbomachine. The gimbal mount includes a plurality of turnbuckles located at equal intervals around the gimbal mount, and the gimbal mount is configured to be mounted to a port or a vessel flange of the turbomachine. Adjustment of the turnbuckles translates into a tangential or axial adjustment of a sensor head position for the probe. An inserting step inserts a probe into the turbomachine through the gimbal mount. An adjusting step adjusts a position of the probe via the gimbal mount. A removing step removes the probe from the turbomachine. An attaching step attaches a traverse actuator system to the gimbal mount. The traverse actuator system is connected to the gimbal mount through a pressure isolation system. A connecting step connects a mounting plate to a complementary mounting plate. The mounting plate is attached to a rail, and the rail supports both the pressure isolation system and the gimbal mount. The mounting plate is configured to align with the complementary mounting plate connected to the traverse actuator system, and a plurality of keys are interposed between the mounting plate and the complementary mounting plate to ensure alignment between the traverse actuator system and the gimbal mount. A reinserting step reinserts the probe back into the turbomachine. An inspecting step inspects and/or tests the turbomachine, and a reading step reads at least one of pressure values, temperature values or moisture values obtained from within the operating turbomachine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a simplified schematic illustration of a combined cycle power plant. 
           [0006]      FIG. 2  illustrates a perspective view of a system for inspecting a turbomachine, according to an aspect of the present invention. 
           [0007]      FIG. 3  illustrates a side view of a system for inspecting a turbomachine, according to an aspect of the present invention. 
           [0008]      FIG. 4  illustrates a perspective view of the pressure isolation system and the gimbal mount, according to an aspect of the present invention. 
           [0009]      FIG. 5  illustrates a cross-sectional view of the pressure isolation system and gimbal mount, according to an aspect of the present invention. 
           [0010]      FIG. 6  illustrates a schematic diagram of a system that may be used to inspect a turbomachine, according to an aspect of the present invention. 
           [0011]      FIG. 7  illustrates a flowchart of a method for inspecting a turbomachine, according to an aspect of the present invention. 
           [0012]      FIG. 8  illustrates a partial side view of the sensor head, according to an aspect of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    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&#39; 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. 
         [0014]    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. 
         [0015]      FIG. 1  is a simplified schematic illustration of a combined cycle power plant  100 . The power plant  100  includes a steam turbine  110 , a generator  120  a gas turbine  130  and a heat recovery steam generator (HRSG)  140 . The steam turbine  110  is connected to the generator via shaft  152  and a clutch (not shown). The generator is connected to the gas turbine via shaft  154 . The exhaust of gas turbine  130  is connected to HSRG  140  via duct  156 , or in some applications the HSRG  140  may either be directly connected to the exhaust of turbine  130  or connected to the exhaust through a diffuser (not shown). The steam turbine  110  converts the thermal energy in steam to rotational movement. Steam strikes the blades of the steam turbine, causing the steam turbine rotor shaft to rotate. The rotating shaft drives the generator  120 . The gas turbine  130 , which includes a compressor  131  and a turbine section  132 , compresses air and mixes it with fuel. The fuel is burned and the hot air-fuel mixture is expanded through the gas turbine blades, making them spin. The spinning gas turbine shaft drives the generator  120 , which converts the spinning energy into electricity. The HSRG  140  turns the gas turbine exhaust heat into steam, and this steam is then fed into steam turbine  110 . 
         [0016]    The steam turbine  110 , compressor  131  and gas turbine  132  are all turbomachines. Turbomachines may include multiple stages of blades, buckets, nozzles and vanes. The blades and buckets are rotating elements including airfoil sections. The airfoil sections are designed for high efficiency. At times, it is desirable to inspect and/or test the operation of turbomachines to either (1) validate predicted operating parameters and conditions, or (2) identify problem locations or components, or operating conditions causing undesired characteristics. In some cases, it may be helpful to monitor pressure or temperature along multiple radial distances near a blade. For example, one reading could be taken near the rotor shaft, a second reading near a blade tip and a third reading near the middle of the blade. In the past this has been very difficult, if not impossible, because one could not easily, safely and accurately move a probe in an operating turbomachine. The turbomachine has to be operating for accurate operating measurements. Unfortunately, the blades rotate circumferentially at high speeds and the machines may be under vacuum or pressure, and this makes moving a probe and maintaining the machine seals problematic. 
         [0017]      FIG. 2  illustrates a perspective view of a system  200  for inspecting a turbomachine, and  FIG. 3  illustrates a side view of a system for inspecting a turbomachine, according to an aspect of the present invention. The system  200  includes a traverse actuator system  210 , pressure isolation system  220  and a gimbal mount  230 . The pressure isolation system  220  is connected to the traverse actuator  210 , and is configured to maintain a pressure resistant seal around the probe  212 . The gimbal mount  230  is connected to the pressure isolation system  220 . The probe  212  may be formed of an elongated shaft with a sensor head  213  at one end and a plurality of output ports  214  located at an opposing end of the shaft. As one example, the sensor head  213  may be a S-port pressure sensor, and accordingly there would be five output ports  214  at an opposing end of the elongated shaft. Alternatively, the sensor head  213  could be a temperature sensor, a moisture or humidity sensor, or a camera or any other desired sensor device. The elongated shaft of probe  212  is sized for the specific turbine or turbomachine. Any suitable length may be employed, as long as the probe can travel the desired distance into the turbomachine. 
         [0018]    The system  200  is configured to mount onto the outer shell or casing of the turbomachine, so that the probe  212  will be aligned to an access port therein. In the example shown, the system  200  is mounted to the steam turbine&#39;s  110  casing. An access port  111  is located in the casing of the steam turbine and the probe  212  passes through this opening. The gimbal mount  230  may be fastened to the port  111  by mechanical fasteners, clamps or any other suitable attachment means. A pair of leveling feet  231  may be used to balance and steady the system against the casing of the steam turbine  110 . 
         [0019]    The traverse actuator  210  includes a carriage  240  configured to move the probe  212  in a linear or radial direction (with respect to the turbomachine) into and out of the turbomachine. A track  215  has a plurality of linearly arranged teeth  217  configured for operation with the carriage  240 . The teeth may be located on one or both sides of the track. A motor  260  is operably connected with the carriage  240  and track  215 , and is configured to engage the teeth of the track so that operation of the motor forces the carriage to move along the track. For example, the motor may be connected to a gearbox and/or a roller pinion that engages the track teeth. When the roller pinion is rotated by the motor, the carriage  240  moves along the track  215 , and the probe moves toward or away from the steam turbine  110 . As  FIG. 2  illustrates, the carriage  240  is at its most forward position indicating that the probe is at the deepest position within steam turbine  110 . The motor can be energized to move carriage back along track  215  to withdraw the probe&#39;s sensor head  213 . 
         [0020]    The traverse actuator  210  also includes an enclosure  250  that is configured to operate in hazardous environments. For example, a hydrogen exclusion zone could be considered a hazardous environment, or any turbomachine that operates under a pressure or vacuum may present hazardous conditions. The enclosure  250  may contain motor  260 , sensors for reading the outputs  214  of probe  212 , and/or any other desired inspection equipment. The traverse actuator may also include a yaw drive  216  configured to rotate the probe about the radial axis. The yaw drive can include a motor and one or more rollers that engage the probe  212 . If the sensor head  213  needs to be rotated, then the yaw drive can adjust the rotational position of the sensor head  213  (e.g., by about +/−180 degrees, +/−150 degrees, etc.). A camera  270  is mounted to the traverse actuator and is configured to observe an insertion location of the probe  212 . The camera  270  is ruggedized and configured to operate in hazardous environments (e.g., it can be explosion resistant). The camera enables an operator to remotely view the system  200  and the insertion location of steam turbine  110 , from a safe and secure location. The camera can be mounted on an extending arm  272  for an elevated worksite view. In addition, the camera  270  can be connected to the remote monitoring station (that has a display) via a wired or wireless link. The camera can be configured to pan or zoom to a specific field of view, all under remote control. 
         [0021]    A leg assembly  280  (e.g., a bipod, tripod, etc.) may also be attached to traverse actuator  210  to stabilize and secure the system. The leg assembly  280  includes a plurality of adjustable length legs configured to lock in position at a desired length. For example, two main legs  281  may be telescopic and have fasteners (e.g., bolts) to lock each leg at a desired length. A third leg  282  may slide within a clamp that also locks the third leg in a desired position and length (e.g., via a clamp). The traverse actuator  210  may also include an articulated cable guide  360  comprised of a plurality of chain links  362 . The articulated cable guide  360  retains a plurality of cables that may extend between the output ports  214  and the enclosure  250 . The cable guide  360  is comprised of two spaced but parallel chain link walls  362 , and a segmented floor  364 . The cables reside between the walls  362  and may be retained by top members  366 . The cable guide  360  follows (e.g., bends and flexes with) the movement of the carriage  240  so that the cables avoid catching on obstructions as the carriage moves back and forth along rail  303 . 
         [0022]      FIG. 4  illustrates a perspective view of the pressure isolation system  220  and gimbal mount  230 , according to an aspect of the present invention.  FIG. 4  illustrates a cross-sectional view of the pressure isolation system  220  and gimbal mount  230 , according to an aspect of the present invention. The pressure isolation system  220  is mounted onto rail  301 , which in turn is connected to leveling feet  231  (only one of which is shown). The probe  212  is shown inserted into the pressure isolation system. A probe bearing  310  facilitates movement of the probe  212 , and the bearing  310  could be comprised of roller bearings, ball bearings or any other suitable low friction device or material. For example, as the probe  212  is moved back and forth (or along a radial axis of the turbomachine) the bearing  310  reduces friction between the probe  210  and the surrounding components of the system. A pressure seal block  320  isolates the pressure within the turbomachine from the external atmosphere, and seals along the outer circumference of probe  212 . The pressure seal block  320  may be connected to a pressurized or vacuum source. For example, if the turbomachine location undergoing inspection is at 10 psi, the seal block could be maintained at about 15 psi to prevent undesired leakage. 
         [0023]    A valve seal  330  is located between the gimbal mount  230  and the pressure seal block  320 . The valve seal  330  is configured to isolate the pressure seal block  320  from the gimbal mount  230  when the probe is not in the valve seal. In addition, the valve seal  330  can be closed to isolate the internal working area of the turbomachine from the external atmosphere. The valve seal may be a ball valve seal (as shown), a guillotine seal or any other suitable seal. 
         [0024]    The gimbal mount  230  mounts to the port flange on the turbomachine&#39;s casing. For example, the gimbal mount may be mounted to the port or vessel flange with the use of bolts and nuts. The leveling feet  231  may then be adjusted until they contact the vessel or casing. The gimbal mount is configured to permit radial and axial adjustment of the probe&#39;s location. When the probe  212  is inserted in the turbomachine the sensor head  213  may be too near or too far away from a blade, or it may be too near or too far away from the rotor shaft. Four turnbuckles  340  are located at 90 degree intervals around the gimbal mount. In  FIG. 4 , the top (i.e., 0 degree) and side (270 degree) turnbuckles are shown, and in  FIG. 5  only the top (0 degree) and bottom (90 degree) turnbuckles are shown. To adjust the axial position of sensor head  213 , the side (first set of) turnbuckles can be adjusted. For example, the 90 degree turnbuckle can be tightened and the 270 degree turnbuckle can be loosened to move the sensor head  213  in the axial direction. To adjust the sensor head in the tangential direction, the 0 degree and 180 degree (second set of) turnbuckles can be respectively tightened and loosened. This adjustability is extremely helpful as the port flanges are not always manufactured to close tolerances and many (if not all) were never designed to be used with highly accurate inspection equipment, such as the present invention. This adjustability also permits the operator to align the probe  212  so that the probe  212  or sensor head  213  do not contact undesired rotating parts of the turbomachine. 
         [0025]    The gimbal mount  230  and pressure isolation system  220  may be attached to the traverse actuator system via mounting plate  350 , which is attached to rail  301 . The traverse actuator system includes a complementary mounting plate  302  (attached to rail  303 ) and the keys  351  ensure proper alignment between the traverse actuator system and the pressure isolation system/gimbal mount. The keys  351 , which may be attached to either mounting plate, are interposed between the mounting plate  350  and the complementary mounting plate  302 . As can be seen, the keys  351  ensure proper alignment between the traverse actuator system  210  and the pressure isolation system  220  and gimbal mount  230 . 
         [0026]      FIG. 6  illustrates a schematic diagram of a system  500  that may be used to inspect a turbomachine, according to an aspect of the present invention. The system  500  includes the traverse actuator  210 , pressure isolation system  220  and gimbal mount  230 , generally indicated by  501 . Four of these systems  501  are distributed around, and are attached to, the turbomachine  110 . However, only the cabling and communication links are shown for one system, for clarity. Each system  501  can inspect a different part or stage of the turbomachine. The turbomachine  110  (e.g., a steam turbine) is located in a hazardous area (located to the right of line  505 ), and a safe area (located to the left of line  505 ) is located away from the steam turbine  110 . The hazardous area may be the area directly around the turbomachine, or a room enclosing the turbomachine. The safe area may be located either a safe distance away from the turbomachine, in a different room or in a remote monitoring station. The system control computer  510  and camera control computer  520  are both located in the safe area. Both the system control computer  510  and the camera control computer may be connected to the enclosure  250  and monitoring station/display  530  by a wired or wireless link. For example, ethernet cables  512  may be employed as a communication link. However, any suitable wired or wireless (e.g., radio frequency, wifi, Bluetooth, etc.) communication link may be employed. In some applications, the system control computer  510  and camera control computer  520  may be combined into a single device. The system control computer  510  or the camera control computer  520  may function as a monitoring station having a display, or the monitoring station/display  530  may be a separate device or located remotely from the system  501  or system  500 . 
         [0027]    The controller  513  may also include power inputs  514  (e.g., 90-240 volts AC) for powering electrical devices, and a pressurized gas input  516  for supplying pressurized gas to the pressure seal block  320  via gas output  517 . For example, pressurized air at about 60 PSI may be supplied to seal block  320  via gas output  517 . A plurality of motor and feedback cables  518  extend between the controller  513  and enclosure  250 . With this arrangement and configuration, a remotely located operator (in the safe area) can monitor and control the inspection process. The cameras  270  may be controlled (e.g., panned, zoomed focused, etc.) by camera control  520 . The system  501  and probe  212  can be controlled with system control computer  510 . The system control computer may also include a display for viewing images from cameras  270 . The system control computer  510  also includes a human machine interface (HMI) for controlling the probe  212 . For example, linear (i.e., radial) movement of the probe is controlled as well as activation of motor  260 , and rotation (i.e., yawing) of the probe  212  by yaw drive  216  is controlled. The system control computer  510  may also display PSI readings, warnings/alarms, temperatures, and any other data that may be of interest during the inspection and/or testing process. 
         [0028]      FIG. 7  illustrates a flowchart of a method  600  for inspecting a turbomachine, according to an aspect of the present invention In step  610 , the gimbal mount  230  is attached to the vessel flange of the turbomachine with mechanical fasteners. The leveling feet  231  are adjusted until they contact the vessel (the vessel is the turbomachine casing), and may be locked in place with lock nuts. In step  620 , a probe or camera may be inserted into the turbomachine through the gimbal mount. In step  630 , the position of the probe is adjusted with the gimbal mount&#39;s turnbuckles  340 . Once the desired probe position and orientation is obtained the turnbuckles may be locked in place with jam nuts. In step  640 , the probe may be removed from the turbomachine and gimbal mount  230 . In step  650 , the traverse actuator  210  is attached to the gimbal mount  230  and pressure isolation system  220  via mounting plates  350 ,  302 . The alignment keys  351  ensure correct probe alignment between the pressure isolation system and the traverse actuator. Mechanical fasteners may be used to attach the traverse actuator to the mounting plate  350 . The traverse actuator system is also connected to the gimbal mount through or via the pressure isolation system. The leg assembly may now be deployed and adjusted to the desired height. The legs of the leg assembly may be telescoping to allow for easy height adjustment. In step  660 , the probe  212  is re-inserted into the turbomachine through the pressure isolation system and gimbal mount. In step  670 , the system is activated to insert the probe into the machine to begin the inspection and/or testing and take readings of various parameters (e.g., pressure, temperature, moisture, etc.). 
         [0029]      FIG. 8  illustrates a partial side view of the sensor head  213 , according to an aspect of the present invention. The sensor head  213  may comprise a pressure probe  800  that has a plurality of ports  801 - 803 . The ports  801 - 803  may be pressure sensing ports and the sensor head may include one to seven or more pressure sensing ports. Multiple ports allow for differential pressure sensing capabilities, and the multiple ports may be evenly or unevenly distributed around the distal end of probe  800 . For example, the pressure at a specific location (e.g., between specific stages, or at specific radial or axial locations) in the turbomachine may be desired and the probe  800  can detect this pressure. The probe  800  may also include a moisture probe/port  810  and a temperature probe/port  820 . Alternatively, the entire probe  800  may be configured as a moisture or temperature probe. The probe  800  may also include a camera  830  or imaging device. For example, the camera  830  can aid in verifying accurate probe placement or in identification of foreign objects/debris or damage. 
         [0030]    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.