Hydrocarbon leak imaging and quantification sensor
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
G01M-003/38
G01N-021/31
G01N-021/85
G01N-033/00
G01N-021/3504
G01N-021/359
G01F-001/66
G01J-003/28
출원번호
US-0598052
(2017-05-17)
등록번호
US-10197470
(2019-02-05)
발명자
/ 주소
Waxman, Allen M.
Bylsma, Jason M.
Vaitses, Allan
출원인 / 주소
MultiSensor Scientific, Inc.
대리인 / 주소
Choate, Hall & Stewart LLP
인용정보
피인용 횟수 :
0인용 특허 :
14
초록▼
This invention consists of sensors and algorithms to image, detect, and quantify the presence of hydrocarbon gas (for example from leaks) using a short-wave infrared radiation detector array with multiple spectral filters under natural sunlight or artificial illumination, in combination with the hyd
This invention consists of sensors and algorithms to image, detect, and quantify the presence of hydrocarbon gas (for example from leaks) using a short-wave infrared radiation detector array with multiple spectral filters under natural sunlight or artificial illumination, in combination with the hydrodynamics of turbulent gas jets and buoyant plumes. Multiple embodiments are recited and address detection and quantification of methane gas leaks. Quantification includes gas column densities, gas concentration estimates, total mass, hole size estimates, and estimated emission flux (leak rate) of gas from holes and cracks in pressurized vessels, pipes, components, and general gas infrastructure, and from surface patches (for example due to gas leaks in underground pipes) under the action of buoyancy and wind. These and similar embodiments are applicable more generally to natural gas and other hydrocarbon gases, liquids, emulsions, solids, and particulates, and to emissions monitoring of greenhouse gases methane and carbon dioxide.
대표청구항▼
1. An imaging device to detect hydrocarbon compounds, comprising: a. An array of at least two discrete photo-detectors, each responsive to light in a wavelength range of approximately 1.0 to 2.6 microns, each having an associated electronic read-out circuit,b. a spectral filter mosaic organized as a
1. An imaging device to detect hydrocarbon compounds, comprising: a. An array of at least two discrete photo-detectors, each responsive to light in a wavelength range of approximately 1.0 to 2.6 microns, each having an associated electronic read-out circuit,b. a spectral filter mosaic organized as a set of filter islands that approximately covers the extent of said array of discrete photo-detectors, whereby each said filter island covers only one discrete photo-detector, such that at least one of said filter islands is appreciably transmissive to light of wavelengths within a first spectral band comprising one or more spectral feature(s) of a hydrocarbon compound of interest, and such that at least one other of said spectral filter islands is appreciably transmissive to light of wavelengths within a second spectral band, wherein the second spectral band is different from the first spectral band,c. a mechanical frame to hold said spectral filter mosaic in front of said array of discrete photo-detectors, such that light passes through said spectral filter array before striking said array of discrete photo-detectors,d. an optical element selected from the group consisting of lenses, curved mirrors, diffractive surfaces, and combinations of said elements, to gather and focus incident illumination such that light at least in a wavelength range of approximately 1.0 to 2.6 microns is directed at said array of discrete photo-detectors so as to first pass through said spectral filters located in front of said array of discrete photo-detectors,e. a mechanical scanning device selected from the group consisting of resonant oscillating mirrors, galvanometric driven mirrors, rotating multi-faceted mirrors, electrically actuated micro-mirror arrays, and dual-axis pan-tilt unit, to scan in two perpendicular directions, thereby establishing an optical field-of-regard to be imaged by said array of discrete photo-detectors,f. at least one electronic circuit to control the integration time of said array of discrete photo-detectors and to convert signals generated by said array of discrete photo-detectors into amplified and digitized signals,g. at least one electronic circuit to synchronize said mechanical scanning device, and said electronic means to read-out and convert said signals generated by said array of discrete photo-detectors, so as to generate a sequence of two-dimensional digital multispectral imagery of multiple spectral bands,h. a processor coupled to: (A) receive said multispectral imagery and a value representative of a distance to a reflective calibration target, so as to calibrate said imagery of each spectral band relative to imagery of said first spectral band, whereby such processing determines calibration parameters comprising a dark level offset and a relative gain for image pixels of interest between said spectral bands, and a relative absorption coefficient for each spectral band characterizing the local atmosphere under conditions of the ambient environment,(B) use said multispectral imagery, in combination with said calibration parameters, to generate an adaptive relative gain across spectral bands, adapted to in-scene reflectors, and a differential optical depth absorption image based on said calibration parameters, so as to determine the possible presence of said hydrocarbon compound of interest in said field-of-regard, employing the Beer-Lambert Law of absorption across the multiple spectral bands, and(C) use said differential optical depth absorption image in combination with a value of internal pressure of an object from which said hydrocarbon compound of interest leaks via a leak hole to estimate a mass flow rate of said hydrocarbon compound of interest out of the leak hole and/or use said differential optical depth absorption image in combination with a value of near ground-level wind speed and direction to estimate a surface emission mass flux of said hydrocarbon compound of interest, andi. electronic circuitry to control the operation of said discrete photo-detectors, said mechanical scanning device, and said processor to calibrate said multispectral imagery, and to generate said absorption image. 2. The imaging device of claim 1 in which said spectral filter islands includes a core band filter that is appreciably transmissive to light of wavelengths within the first spectral band, and a wings band filter that is appreciably transmissive to light of wavelengths both shorter and longer than the core band filter, said wings band filter created from a broadband surround filter that includes said core band, by subtracting said core band filter measurements from said surround filter measurements, accounting for the relative transmission characteristics of said core band and surround filters. 3. The imaging device of claim 1 in which said spectral filter islands includes a core band filter that is appreciably transmissive to light of wavelengths within the first spectral band, and a wings band filter that is appreciably transmissive to light of wavelengths both shorter and longer than said core band filter, said wings band filter created from a broadband filter with a low-transmission notch spanning the wavelengths of said core band filter. 4. The imaging device of claim 1 in which said spectral filter islands includes a core band filter that is appreciably transmissive to light of wavelengths within the first spectral band, and a wings band filter created from one or more filters that are appreciably transmissive to light of wavelengths either shorter or longer than those appreciably transmitted by said core band filter. 5. The imaging device of claim 1 in combination with a visible light camera such that both said imaging devices possess approximately parallel lines-of-sight and share overlapping fields-of-view, by which said absorption image of said hydrocarbon of interest is overlaid on the visible light image, thereby providing spatial context of where in the scene a possible hydrocarbon leak is detected. 6. The imaging device of claim 1 in combination with any of the following ancillary sensors: global positioning sensor to determine said device positional coordinates on the earth, inertial measurement unit to determine said device linear or rotational acceleration components, magnetometer to determine said device orientation with respect to the earth's magnetic field, range finder to determine range of said device from reflecting surfaces in the scene, and weather measurement unit to determine local environmental conditions in proximity to said device. 7. The imaging device of claim 1 in combination with electronic circuits capable of acting on data in ways selected from the group consisting of storing, saving, and transmitting said multispectral imagery, said absorption image, and associate with said imagery data selected from the group consisting of said visible light camera recited in claim 5, and said sensors recited in claim 6. 8. The imaging device of claim 1, wherein said processor is coupled to estimate the mass flow rate of said hydrocarbon compound of interest out of the leak hole by: detecting, within said differential optical depth absorption image, a jet of said hydrocarbon compound of interest originating from the leak hole;determining, for each of a plurality of axial locations along the detected jet, a corresponding average differential optical depth across a cross sectional profile of the detected jet, thereby obtaining a plurality of average differential optical depth data points;determining, based on the plurality of average differential optical depth data points, an average differential optical depth intercept value corresponding to an axial location at a vertex of the jet that is associated with the leak hole;determining, based on the average optical depth intercept value and the value of internal pressure of the object from which said hydrocarbon compound of interest leaks, a size of the leak hole; anddetermining the mass flow rate of said hydrocarbon compound of interest out of the leak hole based on the determined leak hole size and the value of internal pressure of the object from which said hydrocarbon compound of interest leaks. 9. The imaging device of claim 1, wherein said processor is coupled to estimate the surface emission mass flux of said hydrocarbon compound of interest by: detecting, within said differential optical depth absorption image, an emitting surface patch;determining a differential spectral optical depth over the emitting surface patch; anddetermining the surface emission mass flux based on the determined differential optical spectral depth over the emitting surface patch, a speed and a direction of near-surface wind, and a spatial extent of the emitting surface patch in a direction perpendicular to the direction of the wind. 10. The imaging device of claim 1, wherein said processor is coupled to estimate the surface emission mass flux of said hydrocarbon compound of interest based on a relationship between said surface emission mass flux and an average differential optical depth imaged across a surface patch weighted by a wind speed and an extent of said surface patch in a direction perpendicular to a direction of said wind. 11. The imaging device of claim 1, wherein said processor is coupled to estimate the surface emission mass flux of said hydrocarbon compound of interest based on a relationship between said surface emission mass flux and a differential optical depth imaged along downwind edges of a surface patch weighted by a wind speed and an extent of said surface patch in a direction perpendicular to a direction of said wind. 12. The imaging device of claim 1, wherein said processor is coupled to estimate the surface emission mass flux of said hydrocarbon compound of interest based on a relationship between said surface emission mass flux and said absorption imagery inferred rate-of-change of an average differential optical depth weighted by an area of said surface patch in combination with said average differential optical depth across said surface patch weighted by said wind speed and the extent of said surface patch in the direction perpendicular to said wind direction. 13. The imaging device of claim 1, wherein the first spectral band comprises a plurality of spectral features of the hydrocarbon compound of interest. 14. The imaging device of claim 1, wherein the hydrocarbon compound of interest is a gas selected from the group consisting of methane, ethane, propane, butane, pentane, hexane, and octane.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (14)
Moore Gerald (Boggs Township ; Armstrong County PA) Hawley James G. (San Jose CA) Bradley William C. (Gastonia NC) Harper Brian M. (Wildmoor GB2), Apparatus for imaging gas.
Noack Jean-Claude (Cabries FRX) Guern Yves (Jouques FRX) Pelous Grard (Aix en Provence FRX), Method and apparatus for remote optical detection of a gas present in an observed volume.
Komninos Nikolaos I. (2802-B W. Long Dr. Littleton CO 80120), Signal detector and method for detecting signals having selected frequency characteristics.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.