Abstract:
An improved tracer gas leak detection system and method for air inleakage testing of a turbine-condenser system quantified leak testing with two new elements: one, by providing discharge of a fixed, reproducible amount of tracer gas at a possible leak site, which is accomplished by controlling the flow rate, pressure and time interval of the discharge. Secondly, the total amount of tracer gas subsequently detected within the turbine-condenser is determined by integrating the detector response.
Abstract:
A heated, split thermowell comprises a cylindrical shank and integral, axially extending, part-cylindrical probes spaced by at least a first gap defined by a bilateral plane. The thermowell is mounted to the sidewall of a pressure vessel for communicating through a penetration in the sidewall with the fluid state in the pressure vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores, and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the fluid condition of steam versus water. Duplex sensor embodiments permit toggling between different, selected such pairs of probes for on-line testing and verification of monitored conditions and operability of the elements and supporting circuits, with automatic substitution of complementary elements in the event of element failure. Each thermowell also permits on-line replacement of a failed element.
Abstract:
A thermally self-adjusting mount for a proximity sensor for detecting movement of a turbine blade tip within a turbine housing includes an elongated chamber in an interior wall of the turbine housing adjacent the path of travel of the turbine blade tip. The chamber is configured to receive a blade tip sensor therein and accommodate relative movement of the sensor toward and away from the path of travel of the blade tip. A thermally expansive element is operable coupled with the sensor for moving the latter in the chamber toward the path of travel of the blade tip upon heating of the sensor. A spring is provided for maintaining the sensor in contact with the thermally expansive element during both expansion and contraction of the latter. The thermally expansive member is capable, upon being heated to any given temperature, of causing movement of the sensor in the chamber and relatively toward the path of travel of the blade tip a distance which is substantially the same as the linear movement of the wall away from the path of travel due to having been heated to the same temperature. Thus, the spatial relationship between the sensor and the path of travel of the blade tip remains the same at different temperatures.
Abstract:
Fluid flow is determined for a large flow pipe based upon differential pressure across an orifice in the pipe having a known cross-sectional area. In one form, the orifice is variable and adjusted in response to differential pressure so as to maintain differential pressure at a constant value. Flow is determined directly from orifice area. The orifice may be a part of a closed loop flow measurement system which responds to differential pressure changes to adjust orifice area. Various differential pressure settings may be used to accommodate selected back pressures in the flow pipe.
Abstract:
A method is disclosed for eliminating aberrations in position-time data provided by an apparatus which monitors the position of a rotating blade in a turbo machine as a function periodic rotation, the apparatus including at least one sensor adjacent at least one blade position to provide a time signal corresponding to the actual arrival time required for a blade to move from a predetermined position to the at least one sensor position, the aberrations being caused by misalignment or movement of the at least one sensor with respect to a rotating blade. The method comprises the steps of first calculating an average blade arrival time for blade movement from the predetermined position to the at least one sensor position, and then estimating sensor position relative to the predetermined position based on blade velocity and average arrival time. Alternatively, measured displacements between blade position and sensor position at the average blade arrival time may be used to derive a time signal indicative of blade vibration.
Abstract:
A liquid-filled tube placed next to a generator winding section provides an indication of an abnormal hot spot which may develop along the winding. The tube is filled with a liquid which vaporizes to form a vapor bubble at the hot spot location. Acoustic energy is projected through the liquid in the tube and is normally received at the distal end of the tube. Presence of a vapor bubble blocks the acoustic propagation and forms a reflective surface for the acoustic energy which then is utilized to calculate distance to the vapor bubble. With a known pressure versus temperature relationship, the pressure of the liquid is controlled such that the hot spot temperature may be determined.
Abstract:
A generator stator core through-bolt tensioning device that automatically tightens the nut on the through-bolts that hold together and compress laminate plates of the stator core in a high voltage generator. A controller receives a signal from a measuring device, such as a fiber Bragg grating that measures the strain on the bolt, and based on that signal determines whether the nut needs to be tightened. If the controller determines that tightening is necessary, it will cause the tensioning device to automatically tighten the nut while the generator is in service, and use the measuring device to provide feedback of the tensioning of the through-bolt to know when to stop the device from tightening the nut.
Abstract:
A generator stator core through-bolt tensioning device that automatically tightens the nut on the through-bolts that hold together and compress laminate plates of the stator core in a high voltage generator. A controller receives a signal from a measuring device, such as a fiber Bragg grating that measures the strain on the bolt, and based on that signal determines whether the nut needs to be tightened. If the controller determines that tightening is necessary, it will cause the tensioning device to automatically tighten the nut while the generator is in service, and use the measuring device to provide feedback of the tensioning of the through-bolt to know when to stop the device from tightening the nut.
Abstract:
A generator stator core that includes a plurality of through-bolts extending through the stator core. Each through-bolt includes a threaded end on which is positioned a conical washer and a through-bolt nut, where the through-bolt nuts are tightened against the washers to compress laminate plates and hold the stator core together. The stator core further includes a through-bolt tension monitoring system including a fiber Bragg grating sensor mounted to one or more of the conical washers and being provided in at least one optical fiber. The monitoring system further includes a monitoring device providing an optical signal to each of the fiber Bragg grating sensors and receiving a reflected signal from the fiber Bragg grating sensors where the reflected signal provides an indication of strain on the washer to provide an indication of how tight the nut is on the through-bolt.
Abstract:
A method is provided for monitoring velocity of a fluid flow through a predetermined fluid flow space. A fiber optic conductor includes a flow measurement portion defining an elongated dimension extending across a portion of the fluid flow space. The fluid flow in the fluid flow space causes the measurement portion of the fiber optic conductor to flex in a direction transverse to the elongated dimension. Optical radiation is supplied to the fiber optic conductor, and optical radiation is received from the fiber optic conductor after the supplied optical radiation has passed through the measurement portion. The received optical radiation is analyzed to effect a determination of a flow velocity of the fluid flow.