Burner

Abstract

A microtube cluster burner ( 1 ) comprises a multitude of ducts ( 41 ) extending through fluid plenums ( 31, 32, 33 ). Discharge means ( 51, 52 ) fluidly connect the plenums to the ducts. At least one of the ducts ( 41 ) is provided with at least two discharge means ( 51, 52 ) for discharging fluid from a plenum ( 31, 32 ) into the duct at at least two different longitudinal positions of the duct.

1 . A burner ( 1 ) comprising a first, upstream front wall ( 11 ), second downstream front wall ( 12 ), a general airflow direction being from the first, upstream front wall to the second, downstream front wall, wherein at least one partition wall ( 21 ,  22 ,  23 ,  25 ,  26 ) extends across the general airflow direction and between the first and second front walls,
 whereby the at least one partition wall divides a space between the first front wall and the second front wall into at least two separate fluid plenums ( 31 ,  32 ,  33 ,  35 ,  36 ,  37 ,  38 ) stacked along the general airflow direction,   the burner further comprising at least one peripheral wall ( 28 ,  29 ) extending between at least one of: the front walls, at least two partition walls, and/or a front wall and at least one partition wall, wherein a multitude of passages ( 40 ,  40   a ,  40   b ,  40   c ) are provided through the first and second front walls and the at least one partition wall,   wherein a multitude of ducts ( 41 ,  41   a ,  41   b ,  42 ,  43 ,  44   a ,  44   b ,  44   c ,  45 ,  46 ,  47 ,  48 ,  49 ,  141 ,  142 ) are provided, the ducts extending through at least some of the passages and the ducts extending through the fluid plenums wherein the duct walls are leak-proof connected to the first front wall, the second front wall and the at least one partition wall, so as to provide fluid communication between an upstream side of the burner adjacent the first front wall and a downstream side of the burner adjacent the second front wall, and wherein each duct has a first, upstream end adjacent the first, upstream front wall ( 11 ) and a second, downstream end adjacent the second, downstream front wall ( 12 ), wherein the burner comprises discharge means ( 51 ,  52 ,  53 ,  56 ,  57 ,  58 ,  61 ,  61   a ,  61   b ,  61   c ,  62 ,  65 ,  152 ,  162 ) for providing fluid communication between at least one of the fluid plenums and the interior of at least one duct out of the multitude of ducts and each discharge means being configured for discharging a fluid from a fluid plenum into a duct out of the multitude of ducts, wherein at least one of the discharge means is a wall-opening type discharge means ( 51 ,  52 ,  52   a ,  52   b ,  53 ,  56 ,  57 ,  58 ,  152 ) which is provided as at least one through hole through a duct wall and wherein at least one of the discharge means is a nozzle type discharge means ( 61 ,  61   a ,  61   b ,  61   c ,  62 ,  65 ,  162 ) which is provided as a discharge nozzle which is suspended in a duct by a tube ( 132 ) extending from a fluid plenum to the discharge nozzle and providing fluid communication between said fluid plenum and the discharge nozzle, wherein at least one duct ( 43 ,  44   a ,  44   b ,  44   c ,  45 ,  47 ,  48 ,  49 ,  141 ) out of the multitude of ducts is provided with at least two discharge means, wherein said at least two discharge means are provided to discharge a fluid from inside the respective fluid plenum at different positions along a longitudinal direction ( 451 ) of the duct.   
     
     
         2 . The burner according to  claim 1 , wherein at least one duct ( 43 ,  44   a ,  44   b ,  44   c ,  45 ,  47 ,  48 ,  49 ,  141 ) out of the multitude of ducts is fluidly connected to at least two fluid plenums ( 31 ,  32 ,  33 ) by a discharge means, wherein at least one first discharge means is provided for providing fluid communication with a first one of said at least two fluid plenums and at least one second discharge means is provided for providing fluid communication with a second one of said at least two fluid plenums. 
     
     
         3 . The burner according to  claim 1 , wherein at least one duct ( 43 ,  44   a ,  44   b ,  44   c ,  47 ,  49 ,  141 ) out of the multitude of ducts is configured with a first discharge means ( 51 ,  52 ,  53 ,  152 ) which is a wall-opening type discharge means and further with a second discharge means ( 61 ,  61   a ,  61   b ,  61   c ,  62 ,  65 ,  162 ) which is a nozzle type discharge means. 
     
     
         4 . The burner according to  claim 1 , wherein the first discharge means ( 152 ) is in fluid communication with a first fluid plenum ( 37 ) and the second discharge means ( 162 ) is in fluid communication with a second fluid plenum ( 36 ), wherein the first fluid plenum ( 37 ) is arranged downstream from the second fluid plenum ( 36 ) along the general airflow direction and a discharge position (s 1 ) of the discharge nozzle of the second discharge means ( 162 ) providing fluid communication between the duct ( 141 ) and the second fluid plenum ( 36 ) is positioned downstream of the discharge position (s 2 ) of the first discharge means ( 152 ). 
     
     
         5 . The burner according to  claim 1 , wherein a discharge position of any nozzle-type discharge means ( 61 ,  61   a ,  61   b ,  61   c ,  62 ,  65 ,  162 ) is positioned at a longitudinal position of the duct inside which the nozzle-type discharge means is arranged which corresponds to at maximum 20 minimum hydraulic diameters of the respective duct when measured from a downstream end of the duct and along the longitudinal direction of the duct. 
     
     
         6 . The burner according to  claim 1 , wherein at least a subset of the multitude of passages ( 40   b ,  40   c ) are arranged in at least one concentric hexagonal ring around a midpoint of the at least one concentric hexagonal ring, wherein the passages arranged in the at least one concentric hexagonal ring are oriented such that fluid discharged at the downstream side of the burner form the passages in the concentric hexagonal ring has a velocity component which is tangential to a circle defined around the midpoint of the hexagonal ring. 
     
     
         7 . The burner according to  claim 1 , wherein at least one passage is provided with a cartridge ( 60 ) through the passage. 
     
     
         8 . The burner according to  claim 1 , wherein the second fluid plenum ( 35 ), when counted from the downstream side of the burner, is in fluid communication with the fluid surrounding the burner on its lateral sides, and wherein a most downstream fluid plenum ( 33 ) is in fluid communication with said second fluid plenum ( 35 ) when counted from the downstream side of the burner through the partition wall ( 23 ) delimiting the most downstream fluid plenum ( 33 ) from the second fluid plenum ( 35 ) when counted from the downstream side of the burner and further is in fluid communication with the downstream side ( 3 ) of the burner through the downstream front wall ( 12 ). 
     
     
         9 . The burner according to  claim 1 , wherein the most downstream fluid plenum ( 33 ) is in fluid communication with at least one duct through wall-opening type discharge means ( 53 ) provided as through holes in the duct walls. 
     
     
         10 . The burner according to  claim 1 , wherein at least one duct out of the multitude of ducts is configured as a piloting duct ( 49 ) and is in fluid communication with a fluid plenum ( 32 ) different from the most downstream fluid plenum through discharge means ( 65 ) configured to discharge into the piloting duct at a longitudinal distance, when measured from the downstream end of the duct and along a longitudinal extent of the duct, corresponding to at maximum five times the minimum hydraulic diameter of the duct. 
     
     
         11 . The burner according to  claim 1 , wherein a multitude of piloting ducts ( 49 ) are provided and each piloting duct is arranged in the centre of adjacent non-piloting ducts arranged on a concentric hexagon around the piloting duct. 
     
     
         12 . The burner according to  claim 1 , wherein at least a subset of the multitude of passages ( 40   c ;  40   b ,  40   c ) are arranged as outer passages on a concentric hexagonal ring around and adjacent at least one inner passage ( 40   a ;  40   a ,  40   b ), wherein at least one inner duct is provided in the at least one inner passage and at least one outer duct is provided in the outer passages, wherein the at least one inner duct has a most downstream discharge position at which a discharge means in fluid communication with a fluid plenum different from the most downstream fluid plenum is configured to discharge into the at least one inner duct which is positioned at a first longitudinal distance from the downstream end of the at least one inner duct, and wherein the at least one outer duct has a most downstream discharge position at which a discharge means in fluid communication with a fluid plenum different from the most downstream fluid plenum is configured to discharge into the at least one outer duct which is positioned at a second longitudinal distance from the downstream end of the at least one outer duct, wherein the second longitudinal distance is larger than the first longitudinal distance. 
     
     
         13 . The burner according to  claim 1 , wherein each cross-section taken along the longitudinal extent of each duct out of the multitude of ducts has one of a circular or polygonal shape. 
     
     
         14 . The burner according to  claim 1 , wherein the burner comprises at least one supply connector ( 311 ,  321 ,  331 ) for fluid supply of at least some of the fluid plenums, wherein at least two of the fluid plenums ( 31 ,  32 ,  33 ) are fluidly connected to a respective individual supply connector ( 311 ,  321 ,  331 ), wherein at least two supply connectors ( 311 ,  321 ) of different fluid plenums are arranged concentrically and coaxially. 
     
     
         15 . The burner according to  claim 1 , wherein at least one of the through holes ( 52   a ) arranged in the wall of a duct ( 142 ) out of the multitude of ducts for providing fluid communication with a fluid plenum ( 32 ) has an elliptically shaped cross-section, wherein in particular the long axis ( 528 ) of the ellipse includes an angle of at maximum 30 degrees with one of a longitudinal axis of the duct ( 451 ), the general airflow direction or a burner axis, and wherein further in particular the ratio of the length (a) of the long ellipse axis ( 528 ) to the length (b) of the short ellipse axis ( 529 ) is 1.25 or more. 
     
     
         16 . The burner according to  claim 1 , wherein at least one of the through holes ( 52   b ) arranged in the wall of a duct ( 142 ) out of the multitude of ducts for providing fluid communication with a fluid plenum ( 32 ) has a polygonal shaped cross-section having a polygonal shaped boundary, the polygonal shaped boundary comprising straight boundary segments ( 521 ,  522 ,  523 ,  524 ,  525 ), wherein said polygonal shaped boundary comprises an upstream boundary section ( 526 ) and a downstream boundary section ( 527 ), wherein at least one of the upstream boundary section and the downstream boundary section is shaped such that an angle (δ, ε) included between each straight segment of the respective boundary section and one of a longitudinal axis ( 451 ) of the duct, the general airflow direction or a burner axis is smaller than or equal to 45 degrees. 
     
     
         17 . The burner according to  claim 1 , wherein at least a subset of ducts out of the multitude of ducts are provided with a nozzle type discharge means inside the respective duct, whereby an outer boundary of a respective discharge nozzle provided inside a duct defines a closest residual flow cross-section between the discharge nozzle and the inner wall of the duct, wherein at least two ducts ( 44   a ,  44   b ,  44   c ) out of the subset of ducts are provided with different residual flow cross-sections. 
     
     
         18 . The burner according to  claim 1 , wherein at least one duct ( 44   a ,  44   b ,  44   c ) out of the multitude of ducts comprises at least one tapering cross-section longitudinal portion, wherein within a tapering cross-section longitudinal portion the cross-sectional area of the at least one duct tapers downstream the general airflow direction from a first cross-sectional area to a second cross-sectional area smaller than the first cross-sectional area, and wherein a discharge nozzle ( 61   a ,  61   b ,  61   c ) is provided within said at least one duct with a downstream end of said discharge nozzle positioned within a tapering cross-section longitudinal portion, wherein in particular said tapering cross-section longitudinal portion in which the downstream end of said discharge nozzle is provided is configured such that the hydraulic diameter of the duct at the position where the duct has the first cross-sectional area is 1.12 times or more and 2.5 times or less the hydraulic diameter of the duct at the position where the duct has the second cross-sectional area. 
     
     
         19 . The burner according to  claim 17 , wherein at least some of the subset of ducts ( 44   a ,  44   b ,  44   c ) are provided with a discharge means ( 61   a ,  61   b ,  61   c ) provided as a discharge nozzle inside the respective duct and each of said discharge nozzles longitudinally extending, in relation to the general airflow direction, upstream of the tapering cross-section longitudinal portion, inside the tapering cross-section longitudinal portion, or both, wherein at least one first of the discharge nozzles extends further downstream into the respective tapering cross-section longitudinal portion than a second one of said discharge nozzles. 
     
     
         20 . A combustor comprising a combustion space ( 3 ) and further comprising at least one burner ( 1 ) according to any preceding claim, wherein the second, downstream, front wall ( 12 ) of the burner faces the combustion space and the most downstream of the fluid plenums ( 33 ) adjacent the second, downstream front wall is provided as a coolant plenum. 
     
     
         21 . A gas turbine engine comprising a combustor according to  claim 20 .