Abstract:
An apparatus (10) is provided that includes a spatial array of at least two unsteady pressure sensors (18 - 21) placed at predetermined axial locations x 1 - x N disposed axially along a pipe (14) for measuring at least one parameter of a fluid (12) flowing in the pipe (14). The pressure sensors (18 - 21) comprise a plurality of pressure sensing elements such as piezoelectric film sensors (23) for measuring unsteady pressures associated with acoustical pressures and/or vortical disturbances. The sensing elements are disposed circumferentially around the pipe and spaced a predetermined distance. The pressure signals P 1 (t) - P N (t) provided by the pressure sensors (18-21) are processed by a processing unit to provide an output signal indicative of a parameter of the fluid.
Abstract:
A sensor system for sensing a measurand field within an environment includes an optical source, such as a light emitting diode, for providing broadband light to an array of serially coupled sensor elements disposed within an optical fiber (28). Each sensor element includes a fiber grating (Bragg grating) (44) which, when illuminated, reflects a narrow band of light having a specified central wavelength. The optical fiber is deployed in a high strength hermetically sealed capillary tubing structure (5). Within the capillary tube, at least in the area of the sensor elements, the capillary tubing is filled with a high-density, low-compressibility, and high thermal conductivity material, such as a liquid (48), which completely fills all of the void spaces within the capillary tubing between the tubing and the sensor elements such that compressive forces which are exerted on the external surfaces of the tubing are accurately transmitted to the sensor elements.
Abstract:
A method, apparatus and system are provided to measure the process flow of a fluid or medium traveling in a pipe. The system and apparatus feature a standoff and piezoelectric-based sensor arrangement having a plurality of standoffs arranged on a pipe and a plurality of sensor bands, each arranged on a respective plurality of standoffs, each having at least one sensor made of piezoelectric material arranged thereon to detect unsteady pressure disturbances in the process flow in the pipe which in turn can be converted to the velocity of and/or speed of sound propagating within the pipe, and a cooling tube arranged in relation to the plurality of standoffs for actively cooling the sensor band; and further comprise a processing module for converting one or more sensor signals into a measurement containing information about the flow of the fluid or medium traveling in the pipe, as well as a pump and heat exchanger for processing the cooling fluid flowing through the cooling tube. The processing includes maintaining the cooling fluid at a desired operating temperature.
Abstract:
A sensor head characterizes unsteady pressures in a fluid flowing within a pipe,as may be caused by one or both of acoustic waves propagating through the fluid within the pipe and/or pressure disturbances that convect with the fluid flowing in the pipe. The sensor head comprises a rigid support structure and at least one transducer attached to the rigid support structure. The rigid support structure holds the transducer in contact with an outer surface of the pipe. The at least one transducer senses relative movement between the outer surface of the pipe and the support structure and provides a signal indicative of unsteady pressures within the fluid at a corresponding axial position of the pipe in response to the relative movement. The support structure may be attached to each transducer in an array of transducers, and may include a handle secured thereto for manipulating the sensor head into contact with the pipe. Output signals from the transducers are provided to a processing unit, which processes the output signals to provide a signal indicative of at least one parameter of the flow process.