Zolo Technologies, Inc.

Onpoint Technologies, LLC

John Zink Company, LLC

Mg Smart Ventures, LLC

Andrew D Sappey

Bernard Patrick Masterson

Henrik Hofvander

James Howell

Michael John Estes

Gerry Murphy

Pei Huang

Lee A Sutherland

Robert Harr

Dave Giltner

Jim Howell

Rod Harris

David Giltner

Atilio Jobson

Allen Molitoris

David Owenby

Qingchun Zhao

Henrick Hofvander

Bernhard W Bach

Measuring a concentration of at least one target species is described. A first and second tunable diode laser are configured to generate laser light at a respective wavelength different from one another. A pitch head comprising a transmitting optic is optically coupled to the first and second tunable diode lasers via distal ends of the first and second optical fibers, and is oriented to project respective beams from each of the first and second distal ends through a measurement zone. A photodetector is configured to detect an optical power of light in the first and second wavelengths. A catch head located across the measurement zone from the pitch head is in optical communication with the pitch head to receive the respective beams from the first and second distal ends and direct the respective beams to the photodetector.

TDLAS architecture for widely spaced wavelength

A demultiplexed filtering method includes propagating an optical beam from an input optical fiber to a diffraction grating to produce a first and a second diffracted beam having a respective first center wavelength λand a second center-wavelength λ>λof the optical beam. The first diffracted beam propagates back toward the input optical fiber at a first diffracted angle determined in part by λand a diffraction order m1 of the first diffracted beam. The second diffracted beam propagates back toward the input optical fiber at a second diffracted angle determined in part by λand a diffraction order m<m. The method also includes (i) coupling the first diffracted beam into a first optical fiber of a one-dimensional optical-fiber array that includes the input optical fiber, and (ii) coupling the second diffracted beam into a second optical fiber of the one-dimensional optical-fiber array.

Demultiplexing filter and method

Systems for measuring a concentration of a target species include a first and second tunable diode laser generating laser light at a respective first and second wavelength each corresponding to respective absorption lines of the target species. A first optical fiber is optically coupled to the first tunable diode laser, and does not support a fundamental mode at the second wavelength. A second optical fiber is coupled to the second tunable diode laser and does not support a fundamental mode at the first wavelength. A fiber bundle includes respective distal ends of the first and second optical fibers, which are stripped of their respective coatings and arranged with their claddings adjacent to each other. A pitch head is configured to project respective optical beams from the fiber bundle through a measurement zone. A catch head located across the measurement zone receives the projected beams and directs them to a sensor.

TDLAS architecture for widely spaced wavelengths

A tunable diode laser absorption spectroscopy (TDLAS) optical head includes a housing configured for attachment to a sight tube attached to a wall of a process chamber. The TDLAS optical head further includes optics within the housing for transmitting, receiving, or transmitting and receiving a laser beam within a process chamber through the sight tube. The TDLAS optical head further includes a photo sensor in the housing positioned to receive light emitted by combustion within the process chamber to which the housing is attached.

Method and apparatus for monitoring port blockage for TDLAS measurements in harsh environments

A method for measuring a concentration of at least one target species includes generating first and second laser beams having respective first and second wavelengths each corresponding to respective absorption lines of the at least one target species. The method includes coupling the first and second laser beams to proximal ends of first and second fundamental modes of first and second optical waveguides, respectively. The method includes transmitting through a measurement zone, for a distal end of the first and second optical waveguides, a probe signal including the first and second laser beam. The method includes determining a first signal strength of the probe signal at the first wavelength and a second signal strength of the probe signal at the second wavelength, and determining, from the first signal strength and the second signal strength, a concentration of the at least one target species.

Sensing of gas species characteristics within a process chamber includes selectively projecting a beam of a first select lasing frequency therethough. The beam is optically coupled to a detector to detect a process transmission spectrum having an absorption dip at a select lasing frequency caused by a gas species characteristic. The beam is selectively projected through a fiber Bragg grating which is formed in an optical fiber core to partially reflect at least a portion of the beam of the first select lasing frequency while passing a remainder of the beam. The remainder of the beam has an FBG transmission spectrum mimicking the absorption dip at or near the select lasing frequency caused by a gas species characteristic of interest. It is optically coupled the detector. Outputs of the detector are monitored to compare the FBG transmission spectrum to any process transmission spectrum produced in the process chamber.

Method and apparatus for verification of TDLAS system operation

A method of monitoring blockage of a sight tube attached to a wall of a process chamber, the sight tube being operatively associated with a TDLAS optical head with a window between the sight tube and the TDLAS optical head. The method includes the steps of providing a photo sensor in the TDLAS optical head, the photo sensor being positioned to receive light emitted by a light emitting process within the process chamber. An emission signal produced by light emitted by the light emitting process within the process chamber being received by the photo sensor is monitored. A determination is made if the emission signal is degrading.

A system for widely spaced wavelength tunable diode laser absorption spectroscopy includes at least a first and second tunable diode laser generating laser light at a first and second wavelength, wherein laser light of the first and second wavelengths cannot co-propagate efficiently on the same single-mode fiber. A first fiber may be configured to carry light in the first wavelength, and a second fiber configured to carry light in the second wavelength. A fiber bundle may be formed from the distal ends of the first and second fibers stripped of their respective coatings, and arranged with their claddings adjacent to each other. One or more pitch heads are configured to project respective beams of laser light from the fiber bundle through a measurement zone. One or more catch heads located across the measurement zone receive the respective beams and direct the respective beams onto at least one sensor.

A method of monitoring combustion properties in an interior of a furnace is described. A beam of light is projected through a pitch optic including a pitch collimating lens residing outside the boiler interior. The pitch collimating lens projects the beam through a penetration into the boiler interior. The beam of light projected by the pitch collimating lens is reflected from at least one in-furnace retro-reflector, and received with a catch optic substantially identical to the pitch optic residing outside the boiler interior. The pitch optic and the catch optic may be embodied in the same pitch/catch optic. The pitch collimating lens may also be steered toward another of the at least one in-furnace retro-reflectors. Combustion properties may be calculated for each retro-reflector based on retro-reflector zones within the furnace.

In-furnace retro-reflectors with steerable tunable diode laser absorption spectrometer

A method of monitoring combustion properties in an interior of a boiler of the type having walls comprising a plurality of parallel steam tubes separated by a metal membrane. First and second penetrations are provided in the metal membrane between adjacent tubes on opposite sides of the boiler. A beam of light is projected through a pitch optic comprising a pitch collimating lens and a pitch relay lens, both residing outside the boiler interior. The pitch relay lens projects the beam through a penetration into the boiler interior. The beam of light is received with a catch optic substantially identical to the pitch optic residing outside the boiler interior. The strength of the collimated received beam of light is determined. At least one of the pitch collimating lens and the catch collimating lens may then be aligned to maximize the strength of the collimated received beam.

Method and apparatus for monitoring combustion properties in an interior of a boiler

An apparatus and methods for measuring combustion parameters in the measurement zone of a gas turbine engine. The measurement zone is defined as being between an outer casing and an engine component having a reflecting surface inside the outer casing. The apparatus comprises a laser generating a transmitting beam of light of a select wavelength and a multimode transmitting fiber optically coupled to the laser. A transmitting optic is optically coupled to the multimode optical fiber for transmitting the beam into the measurement zone. The reflecting surface is configured to provide a Lambertian reflection. A receiving optic is positioned to receive the Lambertian reflection. Means are provided in operative association with the multimode transmitting fiber for averaging modal noise induced signal level variation of light propagating within the multimode transmitting fiber.

Mitigation of optical signal noise using a multimode transmit fiber

A method of absorption spectroscopy to determine a rapidly variable gas parameter. The method includes transmitting light from a synchronization light source to a synchronization detector. The transmitted light is periodically interrupted by a moving mechanical part between the synchronization light source and synchronization detector. The output from the synchronization detector is used to generate a repeating time signal having variable phase delay. This signal is used to control the timing of laser spectroscopy wavelength scans. Multiple spectroscopic scans may be repeated at multiple selected time signal phase delay and the results averaged for each phase. Apparatus for implementing the above methods are also disclosed.

Time-synchronized TDLAS measurements of pressure and temperature in a gas turbine engine

A method for measuring combustion parameters within a combustion zone of a gas turbine engine, the combustion zone being defined between an inner and outer casing. The method includes transmitting a beam from a transmit optic optically coupled to a bore in the outer casing off a portion of the inner casing and receiving a portion of the beam reflected off the inner casing with a receiving optic optically coupled to a bore in the outer casing. An apparatus for practicing the method includes a laser generating a beam and a transmitting/receiving optics pair, the transmitting/receiving optics pair being configured for operative association with a port in an outer casing of a gas turbine engine, whereby the transmitting/receiving optics are in optical communication by reflecting the beam off a portion of an inner casing.

Method and apparatus for spectroscopic measurements in the combustion zone of a gas turbine engine

A method of absorption spectroscopy including obtaining absorption data at multiple wavelengths along more than one line-of-sight path through a quantity of gas of interest. The method further includes identifying more than one temperature and gas species concentration bin along the multiple line-of-sight paths and creating a map of temperature and gas species concentration. The map thus created will have at least two-dimensional information derived from select temperature and gas species concentration bins identified along more than one line-of-sight path. Apparatus for implementing the above method is also disclosed.

Binning and tomography for high spatial resolution temperature and species concentration measurements

A method of sensing a process utilizing a sensing apparatus consisting of more than one diode laser having select lasing frequencies, a multiplexer optically coupled to the outputs of the diode lasers with the multiplexer being further optically coupled to a pitch side optical fiber. Multiplexed laser light is transmitted through the pitch side optical fiber to a pitch optic operatively associated with a process chamber which may be a combustion chamber or the boiler of a coal or gas fired power plant. The pitch optic is oriented to project multiplexed laser output through the process chamber. Also operatively oriented with the process chamber is a catch optic in optical communication with the pitch optic to receive the multiplexed laser output projected through the process chamber. The catch optic is optically coupled to an optical fiber which transmits the multiplexed laser output to a demultiplexer. The demultiplexer demultiplexes the laser light and optically couples the select lasing frequencies of light to a detector with the detector being sensitive to one of the select lasing frequencies.

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Lakewood, CO, United States of America

Andrew D Sappey