Burner monitor and control

Abstract

A monitoring and control apparatus ( 220 ) adapted to monitor the combustion of each individual burner ( 224 ) in a furnace ( 1 ). It includes at least one laser ( 221 ) for providing a beam ( 223 ) through a flame of a burner ( 224 ) in a furnace ( 1 ), and at least one detector ( 222 ) for detecting the beams ( 223 ) after they pass through/near the flame. The monitored signal is passed to an electronics unit ( 215 ) that calculates optimum conditions for this burner ( 224 ). The electronics unit ( 215 ) then causes control unit ( 214 ) to adjust the fuel, primary air and secondary air feeds each individual burner ( 224 ) to result in a more efficient system that reduces the amount of emissions released.

1 . A burner efficiency system ( 200 ) for adjusting the operation of individual burner ( 224 ) of a tangentially fired furnace ( 1 ) comprises:
 a detector ( 222 ) adapted to receive an optical beam ( 223 ) and for provide an electrical signal corresponding to the optical beam ( 223 ) received;   an optical source ( 221 ) positioned to create an optical beam ( 223 ) that passes through a sampling zone ( 8 ) and crosses a trajectory ( 42 ) of a single flame emanating from an individual burner ( 224 ) and impinges upon the detector ( 223 );   an electronics unit ( 214 ) adapted to receive the signal created by the detector ( 222 ) and identify at least one physical property of material between the optical source ( 221 ) and detector ( 222 ) and create an adjustment signal indicating parameters of said individual burner that should be adjusted to optimize the operation of this individual burner ( 224 ).   
     
     
         2 . The burner efficiency system ( 200 ) of  claim 1 , wherein said parameters are selected from the group consisting of:
 a secondary air flow rate into the furnace ( 1 ),   a primary air flow rate into the furnace ( 1 ), and   a fuel flow rate into the furnace ( 1 ).   
     
     
         3 . The burner efficiency system ( 200 ) of  claim 1 , further comprising:
 a secondary air feed ( 207 ) for providing additional combustion air to said furnace ( 1 );   a control unit ( 214 ) coupled to the electronics unit ( 215 ), and to the secondary air feed adapted to adjust the amount of air provided to the burner ( 224 ) based upon the adjustment signal provided by the electronics unit ( 215 ).   
     
     
         4 . The burner efficiency system ( 200 ) of  claim 3 , further comprising:
 a fuel feed ( 105 ) coupled to the control unit ( 214 ), the fuel feed adapted to provide solid fuel particles to the furnace ( 1 );   a primary air feed ( 206 ) coupled to the control unit ( 214 ), the primary air feed adapted to provide air to entrain sold fuel particles and carry them into the furnace ( 1 ); and   wherein the control unit is further adapted to regulate the fuel feed ( 205 ) and primary air feed ( 206  to adjust the amount of fuel particles and primary air provided to furnace ( 1 ) based upon the adjustment signal received form electronics unit ( 215 ).   
     
     
         5 . The burner efficiency system ( 200 ) of  claim 1  wherein the optical source ( 221 ) is a laser, and the detector ( 222 ) is adapted to sense laser light. 
     
     
         6 . The burner efficiency system ( 200 ) of  claim 1  wherein the physical property identified comprises one of the group consisting of:
 temperature, oxygen ( 02 ) concentration, carbon monoxide (CO) concentration, carbon dioxide (CO 2 ) concentration, water vapor concentration, sulfur dioxide (SO 2 ) concentration, sulfur trioxide (SO 3 ) concentration, nitrogen dioxide (NO 2 ) concentration, nitrogen trioxide (NO 3 ) concentration, mercury (Hg) concentration, unburned hydrocarbon concentration and unburned fuel concentration. 
 
     
     
         7 . The burner efficiency system ( 200 ) of  claim 1  wherein the optical beam ( 223 ) crosses the flame trajectory ( 42 ) an intersection point ( 45 ). 
     
     
         8 . The burner efficiency system ( 200 ) of  claim 1  wherein the distance from the intersection point  45  to its corresponding burner ( 224 ) is the same for all burners ( 224 ). 
     
     
         9 . The burner efficiency system ( 200 ) of  claim 1  wherein there are a plurality of burners ( 224 ) on multiple levels of furnace  1 , and there is a plurality of an optical sources ( 221 ) each positioned to create an optical beam ( 223 ) crosses a trajectory ( 42 ) of a flame emanating from a single burner ( 224 ) and impinges upon a detector ( 223 ). 
     
     
         10 . An apparatus ( 200 ) for monitoring a property of at least one constituent in flue gas from a furnace ( 1 ), the apparatus comprising:
 an optical monitoring system ( 220 ) comprising at least one optical source ( 221 ) adapted to provide an optical beam ( 223 ) through flue gasses substantially produced by a single burner ( 224 ) of a furnace ( 1 ), and   at least one detector ( 222 ) adapted to detect the optical beam ( 223 ) and provide a monitored signal to an electronics unit ( 215 ),   the electronics unit ( 215 ) configured to estimate a property of at least one constituent in the sampling zone and create an adjustment signal to adjust the operation of said furnace ( 1 ).   
     
     
         11 . The apparatus ( 200 ) as in  claim 10 , wherein the at least one laser ( 121 ) comprises a semiconductor tunable optical laser. 
     
     
         12 . The apparatus ( 200 ) as in  claim 10 , wherein the constituent comprises at least one of CO, CO 2 , Hg, SO 2 , SO 3 , NO x , O 2 , Hg and unburned fuel. 
     
     
         13 . The apparatus ( 200 ) as in  claim 10 , wherein the property comprises at least one of a presence, a quantity, a density, a concentration of said constituent and a rate of change of any of these properties. 
     
     
         14 . The apparatus ( 200 ) as in  claim 10 , further comprising a control unit ( 214 ) adapted to receive the adjustment signal and control the furnace ( 1 ). 
     
     
         15 . The apparatus ( 200 ) as in  claim 14 , wherein the control unit ( 214 ) is configured to control a flow of at least one of a fuel feed ( 205 ), a primary air feed ( 206 ) and a secondary air feed ( 207 ) to said furnace ( 1 ). 
     
     
         16 . The apparatus ( 200 ) as in  claim 10 , comprising a plurality of lasers ( 221 ) for providing a plurality of beams ( 223 ) and a plurality of detectors ( 222 ) for detecting the plurality of beams ( 223 ). 
     
     
         17 . The apparatus ( 200 ) as in  claim 10 , wherein the plurality of lasers ( 221 ) and the plurality of detectors ( 222 ) are arranged for monitoring a tangentially-fired furnace ( 1 ). 
     
     
         18 . The apparatus ( 200 ) as in  claim 10 , wherein the electronics unit ( 215 ) comprises machine executable instructions stored on machine-readable media, the instructions comprising instructions for:
 estimating a property of the at least one constituent;   determining an adjustment signal from the estimated property to cause the estimated property to become closer to a predetermined value; and   providing an adjustment signal to the control unit ( 214 ).   
     
     
         19 . The apparatus ( 200 ) as in  claim 18 , further comprising instructions for modulating the optical signal. 
     
     
         20 . The apparatus ( 200 ) as in  claim 10 , wherein the beams ( 223 ) pass through two or three dimensions of the combustion system ( 1 ). 
     
     
         21 . A method for adjusting the operation of individual burner ( 224 ) of a tangentially fired furnace ( 1 ) comprising the steps of:
 creating an optical beam ( 223 ) that passes through a sampling zone ( 8 ) and crosses a trajectory ( 42 ) of a flame emanating from an individual burner ( 224 ) and impinges upon a detector ( 223 );   sensing the optical beam ( 223 ) at the detector;   creating an electrical signal corresponding to the sensed optical beam ( 223 );   identifying at least one physical property of material in the sampling zone ( 8 ) from the created electrical signal;   comparing the identified physical properties to a predetermined desired level;   calculating adjustments of a set of burner parameters that would cause the identified physical property to adjust toward the predetermined desired level;   adjusting the burner parameters of the individual burner according to the calculated adjustments to optimize the operation of the individual burner ( 224 ).   
     
     
         22 . The method as in  claim 21 , wherein at least one of the identifying and the adjusting is performed on a real-time basis.