Abstract:
The present invention provides a valve control apparatus which can be programmed to deliver a desired flow of gas. A valve 22 is connected to a stepper motor 28 which is controlled by a computer 32 to open or close the valve in steps within a gas flow line 24 to deliver a desired rate of flow. A flowmeter 30 is provided along the gas flow line 24 for measuring the flow and inputting this flow to the computer 32. The computer 32 calculates rate of flow information obtained from the flowmeter 30 and controls the stepper motor 28 to open or close the valve 22 as necessary in accordance with the received rate of flow information and a desired rate of flow preprogrammed into the computer 32. As a result, a precise desired rate of flow can be obtained. Also, position indicators 34 may be added to the valve 22 to indicate when the valve 22 is completely open or completely closed. The valve 22 may be provided with a return spring 36 to automatically close the valve 22 in the event of a power loss. The computer 32 may be programmed to detect a significant increase in the rate of gas flow being closing the valve 22 accordingly. Additionally, a pressure switch 38 may be provided along the gas flow line 24 to cause the valve 22 to close upon a pressure change. Finally, temperature 40 and pressure 42 sensors may be added along the gas flow line so that the computer 32 can calculate and maintain a specific mass flow of gas.
Abstract:
A method for monitoring turbine blade vibrations comprises the step of transmitting a continuous wave of microwave energy toward a rotating row of blades. Each passage of an individual blade tip through the path of the continuous wave produces a signal indicative of the time at which each passage occurs. The signal is then monitored and analyzed to detect blade vibrations. The signal can be based on a standing wave or a reflected wave.
Abstract:
A method of matching sensors in a multi-probe blade vibration monitor for a turbine. The method includes providing at least two probes mounted in a casing of the turbine adjacent to a rotating blade structure of the turbine. Targets are provided on radially outer portions of the blade structure. Each of the probes includes a sensor generating signals corresponding to target passing events, and a set of synchronous harmonics of the rotational speed of the rotor are produced for each sensor. The position of the sensors is adjusted such that the sets of harmonics of the sensors are substantially matched, indicating that the positions of the sensors are matched.
Abstract:
A system and method for monitoring the condition of a vibration sensor in a system. Vibrations are received in the system at one or more vibration sensors. Sensor data is output by the vibration sensor(s). The sensor data includes data representative of the vibrations in the system and data representative of a natural frequency of the corresponding vibration sensor. The sensor data output from the vibration sensor(s) is monitored, and upon a change in the data representative of the natural frequency of a vibration sensor, that vibration sensor is flagged.
Abstract:
A component sensing system for monitoring the condition of ceramic tiles in a combustion chamber of a gas turbine engine. The sensing system includes an optical fiber that is mounted to the component being monitored, for example, the ceramic tiles in the gas turbine combustion chamber. The optical fiber can be formed in any suitable orientation or configuration, such as a meandering or serpentine orientation. The fiber is optically coupled to a Brillouin signal analyzer that provides an optical pulse to the sensing section of the fiber and detects Brillouin backscattering from the fiber as the pulse travels along the fiber. The frequency of the Brillouin backscattering signal is monitored relative to the distance along the sensing section of the fiber. A rise in temperature at a location of the fiber shows up in the analyzer as an increase in frequency of the backscattered signal.
Abstract:
A method for measuring the differential emissivity between two sites on the surface of a body and the temperature of the two sites. The method includes a plurality of measurements of the infrared radiation arising from each of the two sites under a number of different conditions. Some of the measurements include irradiation by external infrared radiation at a known wavelength and intensity. The infrared radiation arising from each of the sites may include emitted radiation, reflected ambient radiation, and reflected external radiation. Additionally, the temperature determined using the method described can be used to calibrate infrared imaging devices used to inspect the entire body.
Abstract:
A method of matching sensors in a multi-probe blade vibration monitor for a turbine. The method includes providing at least two probes mounted in a casing of the turbine adjacent to a rotating blade structure of the turbine. Targets are provided on radially outer portions of the blade structure. Each of the probes includes a sensor generating signals corresponding to target passing events, and a set of synchronous harmonics of the rotational speed of the rotor are produced for each sensor. The position of the sensors is adjusted such that the sets of harmonics of the sensors are substantially matched, indicating that the positions of the sensors are matched.
Abstract:
A method of monitoring vibrations in a blade structure of a turbine including generating signals from a sensor located adjacent to a radial outer edge of the blade structure to sense passage of targets located on the blade structure. The sensor is mounted eccentrically and the signals are obtained with the sensor located at different angular positions. In a first aspect of the invention, the signals from the sensor are used to determine a target slope angle of a target on a first turbine blade during operation of the turbine. In a second aspect of the invention, the signals from the sensor are used to position the sensor in response to a sensed variation in the axial position of the target on the first turbine blade.
Abstract:
A method of measuring vibration in a bladed rotor structure with a vibration monitor. The vibration monitor includes a sensor for sensing passage of the sensor targets on radially outer portions of the blade structure, and the sensor generates signals corresponding to target passing events. An excitation structure is provided including at least one air jet for providing an excitation force to the blade structure. The blade structure is rotated about an axis of rotation and the air jet is driven in a circular path about the axis of rotation at a different rotational speed to apply a non-synchronous excitation force to the blade structure.
Abstract:
A method for measuring the differential emissivity between two sites on the surface of a body and the temperature of the two sites. The method includes a plurality of measurements of the infrared radiation arising from each of the two sites under a number of different conditions. Some of the measurements include irradiation by external infrared radiation at a known wavelength and intensity. The infrared radiation arising from each of the sites may include emitted radiation, reflected ambient radiation, and reflected external radiation. Additionally, the temperature determined using the method described can be used to calibrate infrared imaging devices used to inspect the entire body.