Dense/Dilute Pulverized Coal Separator Structure of Single-fireball Octagonal Direct-flow Burner

Abstract

The invention discloses a dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner, of which a boiler body is provided with eight burner groups, each water cooled wall is provided with two burner groups respectively, each of the burner groups comprises multiple nozzles toward the same burner, and center lines of all nozzles on the eight burner groups form an imaginary tangent circle in a furnace along the same tangential direction. In the dense/dilute pulverized coal separator structure, eight burner groups are arranged on four water cooled walls of the boiler, thus increasing pulverized coal concentration of a pulverized rich coal area, allowing wall heat load qHr of a lower burner area to be higher, allowing burning temperature of the area to meet requirements for anthracite burning stability, shortening distance of jet flow from a nozzle outlet to downstream adjacent air flow, being capable of using lower primary pulverized coal air flow velocity, enhancing heat flow intensity at the nozzle outlet, improving convection and radiation heat transfer capacity, and ensuring timely ignition of pulverized anthracite air flow and stable burning of the boiler at low load without oil.

1 . A dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner, comprising:
 a boiler body ( 1 ) surrounded by four water cooled walls ( 9 ), wherein an inner space formed by the four water cooled walls ( 9 ) is a furnace ( 2 ) of the boiler body ( 1 );   multiple burners ( 10 ) which are arranged on the water cooled walls ( 9 ) respectively and communicated with the furnace ( 2 ) through the water cooled walls ( 9 ), and on which nozzles toward inside of the furnace ( 2 ) are arranged;   pulverized coal pipelines ( 5 );   a dense/dilute pulverized coal separator ( 4 ) which are connected with the multiple burners ( 10 ) respectively by the pulverized coal pipelines ( 5 ); and   multiple coal mills ( 3 ) which are connected with the dense/dilute pulverized coal separator ( 4 ) by the pulverized coal pipelines ( 5 );   each of the boiler body ( 1 ) being provided with at least one of the coal mill ( 3 );   and characterized in that the boiler body ( 1 ) is provided with eight burner groups, each of the water cooled wall ( 9 ) is provided with two burner groups respectively, each burner group comprises multiple nozzles toward the same burner ( 10 ), and center lines of all nozzles on the eight burner groups form an imaginary tangent circle ( 11 ) in the furnace ( 2 ).   
     
     
         2 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 1 , characterized in that the four water cooled walls ( 9 ) of the boiler body ( 1 ) are respectively arranged as a front wall, a rear wall, a left wall and a right wall of the boiler body ( 1 ), the front wall is arranged opposite to the rear wall, and the left wall is arranged opposite to the right wall; center line of the nozzle of the burner ( 10 ) arranged on the front wall or the rear wall intersects with the water cooled wall ( 9 ) at which the nozzle is located at an intersection point, distance between the intersection point and a joint with the nearest adjacent water cooled wall ( 9 ) is L1, 1/10Lw≦L1≦ 4/10Lw, and Lw is distance between the front wall and the rear wall of the boiler body ( 1 ). 
     
     
         3 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 2 , characterized in that center line of the nozzle of the burner ( 10 ) arranged on the left wall or the right wall intersects with the water cooled wall ( 9 ) at which the nozzle is located at an intersection point, distance between the intersection point and a joint with the nearest adjacent water cooled wall ( 9 ) is L2, 1/10Ld≦L2≦ 4/10Ld, and Ld is distance between the left wall and the right wall of the boiler body ( 1 ). 
     
     
         4 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 1 , characterized in that the center line of the nozzle of the burner ( 10 ) intersects with the water cooled wall ( 9 ) at which the nozzle is located at an intersection point, the intersection point and center of the imaginary tangent circle ( 11 ) form a straight line, and an included angle a is arranged between the straight line and the center line of the nozzle of the burner ( 10 ), 0°≦a≦30°. 
     
     
         5 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 1 , characterized in that each of the burner group is divided into two subgroups along the vertical direction, and the two subgroups are a first burner subgroup arranged at a lower part of the water cooled walls ( 9 ) and a second burner subgroup arranged at an upper part of the water cooled walls ( 9 ) respectively. 
     
     
         6 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 5 , characterized in that the first burner subgroup comprises a primary air/pulverized rich coal burner on which at least one primary air/pulverized rich coal nozzle ( 6 ) and two secondary air nozzles ( 8 ) are arranged along the vertical direction, and the primary air/pulverized rich coal nozzle ( 6 ) and the secondary air nozzles ( 8 ) are arranged at an interval. 
     
     
         7 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 6 , characterized in that the second burner subgroup comprises a primary air/pulverized lean coal burner on which at least one primary air/pulverized lean coal nozzle ( 7 ) and two secondary air nozzles ( 8 ) are arranged along the vertical direction, and the primary air/pulverized lean coal nozzle ( 7 ) and the secondary air nozzles ( 8 ) are arranged at an interval. 
     
     
         8 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 7 , characterized in that an outlet of each of the coal mill ( 3 ) is connected with multiple pulverized coal pipelines ( 5 ), and each of the pulverized coal pipeline ( 5 ) is divided into a pulverized rich coal pipeline and a pulverized lean coal pipeline by the dense/dilute pulverized coal separator ( 4 ). 
     
     
         9 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 8 , characterized in that the pulverized rich coal pipeline is provided with a pulverized coal distributor ( 12 ) and divided into multiple thin pulverized rich coal pipelines by the pulverized coal distributor ( 12 ), and the multiple thin pulverized rich coal pipelines are connected with the multiple primary air/pulverized rich coal nozzles ( 6 ) respectively;
 the pulverized lean coal pipeline is provided with a pulverized coal distributor ( 12 ) and divided into multiple thin pulverized lean coal pipelines by the pulverized coal distributor ( 12 ), and the multiple thin pulverized lean coal pipelines are connected with the multiple primary air/pulverized lean coal nozzles ( 7 ) respectively.   
     
     
         10 . The dense/dilute pulverized coal separator structure of a single-fireball octagonal direct-flow burner according to  claim 7 , characterized in that distance between the primary air/pulverized lean coal nozzle ( 7 ) arranged at the uppermost part and the primary air/pulverized rich coal nozzle ( 6 ) arranged at the lowermost part is between 1 m and 2 m.