Equipment and method for three-dimensional radiance and gas species field estimation in an open combustion environment

Abstract

Process for measuring emission for a flame in an open combustion environment. A captured image is received from each of a plurality of image capturing devices in at least one selected spectral band. Each of the plurality of image capturing devices is trained on the flame from the combustion process from a different perspective view angle. A spectral path length of the flame in the at least one spectral band is estimated from the captured images. Emitted radiance of the flame is estimated from the captured images, and a temperature of the flame is estimated from the estimated emitted radiance. A gas species concentration of the flame is estimated from the temperature of the flame and the spectral path length of the flame. Emission for the flame is measured from the gas species concentration.

1 . A process for estimating a three-dimensional (3D) radiance field of a combustion process in an open combustion environment, comprising:
 receiving a captured image from each of a plurality of image capturing devices in at least one selected spectral band, wherein each of the plurality of image capturing devices is trained on a flame from the combustion process from a different perspective view angle;   for each of the received images, transforming the intensities of the respective image to received radiances, to provide a plurality of radiance images; and   estimating, using a computer processor, the 3D radiance field within a virtual bounding volume surrounding the flame based on a two-dimensional (2D)-to-3D transforming of the radiance images.   
     
     
         2 . The process according to  claim 1 , wherein the image capturing device comprise multi-spectral image-capturing devices;
 wherein the process further comprises, for each of a selected one or more of the plurality of spectral bands, capturing the images of the flame from each of the plurality of multi-spectral image-capturing devices; and   wherein said receiving a captured image comprises, for each of the selected one or more of the plurality of spectral bands, receiving the captured image from each of the plurality of multi-spectral image-capturing devices; and   wherein said estimating the 3D radiance field comprises estimating the 3D radiance fields of each of the selected one or more of the plurality of spectral bands within the virtual bounding volume.   
     
     
         3 . The process of  claim 1 , further comprising:
 performing an intensity-temperature calibration based an association between an intensity of an image pixel and an actual temperature associated with the combustion process;   wherein said transforming is based on the performed intensity-temperature calibration.   
     
     
         4 . The process of  claim 1 , further comprising:
 performing a registration and alignment estimation of the received images based on positional information of the plurality of image-capturing devices and positional information of the flame in the open combustion environment; and   aligning the plurality of radiance images based on the registration estimation;   wherein said two-dimensional (2D)-to-3D transforming is of the aligned radiance images.   
     
     
         5 . The process of  claim 4 , further comprising:
 performing an intensity-temperature calibration based an association between an intensity of an image pixel and an actual temperature associated with the combustion process, wherein said transforming is based on the performed intensity-temperature calibration; and   performing a perspective transformation on the aligned plurality of radiance images to correct for relative motion of the image-capturing devices.   
     
     
         6 . The process of  claim 1 , wherein at least one of the image-capturing devices is transiently positioned with respect to the flame;
 wherein the method further comprises determining a position of the at least one image-capturing device at a time when the image from that image-captured device is captured.   
     
     
         7 .- 19 . (canceled) 
     
     
         20 . An apparatus for measuring emission for a flame in an open combustion environment, comprising:
 a plurality of image capturing devices for capturing images in at least one selected spectral band, wherein each of the plurality of image capturing devices is trained on the flame from the combustion process from a different respective view angle;   a processor in communication with the plurality of image capturing devices, the processor being configured to:   receive a captured image from each of the plurality of image capturing devices;   estimate a spectral path length of the flame in the at least one spectral band from the captured images;   estimate an emitted radiance of the flame from the captured images; estimate a temperature of the flame from the estimated emitted radiance;   estimate a gas species concentration of the flame from the estimated temperature of the flame and the estimated spectral path length of the flame; and   measure emission for the flame from the estimated gas species concentration.