Pulverized coal combustion boiler

Abstract

A pulverized coal combustion boiler 100 comprising: a furnace 50 ; a plurality of burners 6 for supplying and burning pulverized coal fuel in the furnace arranged at positions of a plurality of stages having different heights on a furnace front wall 51 and a furnace rear wall 52 of furnace wall surfaces forming the furnace 50 , the furnace rear wall 52 arranged for facing the furnace front wall 51 ; a plurality of mills 2 arranged for supplying the pulverized coal fuel to the plurality of burners 6 arranged at each of the plurality of stages; and pulverized fuel pipes 5 arranged for distributing and supplying the pulverized coal to the plurality of burners 6 at each of the stages of the furnace front wall 51 and the furnace rear wall 52 from each of the plurality of mills 2.

1 . A pulverized coal combustion boiler comprising:
 a furnace;   a plurality of burners for supplying and burning pulverized coal fuel in the furnace arranged at positions of a plurality of stages having different heights on a furnace front wall and a furnace rear wall of furnace wall surfaces forming the furnace, the furnace rear wall arranged for facing the furnace front wall;   a plurality of mills arranged for supplying the pulverized coal fuel to the plurality of burners arranged at each of the plurality of stages; and   pulverized fuel pipes arranged for distributing and supplying the pulverized coal to the plurality of burners at each of the stages of the furnace front wall and the furnace rear wall from each of the plurality of mills.   
   
   
       2 . The pulverized coal combustion boiler according to  claim 1 , further comprising
 water pipes arranged on a plurality of water pipe walls constituting the furnace wall surfaces of the furnace, wherein   the water pipes arranged on the water pipe walls at a lower part of the furnace wall surfaces are arranged in spirals, and   the water pipes arranged on the water pipe walls at an upper part of the furnace wall surfaces are arranged in the vertical direction by straight pipes connected to the water pipes arranged in spirals.   
   
   
       3 . The pulverized coal combustion boiler according to  claim 1 , further comprising:
 first pulverized fuel pipes for distributing and supplying the pulverized coal from one of the plurality of mills to some of the plurality of burners arranged to face each other on the furnace front wall and the furnace rear wall of each of the stages; and   second pulverized fuel pipes for distributing and supplying the pulverized coal from the other of the plurality of mills to other some of the plurality of burners arranged to face each other on the furnace front wall and the furnace rear wall of each of the stages.   
   
   
       4 . The pulverized coal combustion boiler according to  claim 3 , wherein the burners connected to the first pulverized fuel pipes and the burners connected to the second pulverized fuel pipes are arranged to be adjacently alternately positioned on the furnace front wall and the furnace rear wall of each of the stages. 
   
   
       5 . The pulverized coal combustion boiler according to  claim 1 , wherein
 the burners disposed on each of the stages are arranged in a staggered pattern such that the position at the height of the furnace wall surface of the burners arranged on the furnace rear wall and the position at the height of the furnace wall surface of the burners arranged on the furnace front wall are different.   
   
   
       6 . The pulverized coal combustion boiler according to  claim 1 , wherein
 the burners disposed on each of the stages are arranged such that the position at the height of the furnace wall surface of the burners arranged on the furnace rear wall and the position at the height of the furnace wall surface of the burners arranged on the furnace front wall are substantially the same.   
   
   
       7 . The pulverized coal combustion boiler according to  claim 3 , wherein
 the burners connected to the first pulverized fuel pipes and disposed on the furnace front wall are arranged to face the burners connected to the first pulverized fuel pipes and disposed on the furnace rear wall, and   the burners connected to the second pulverized fuel pipes and disposed on the furnace front wall are arranged to face the burners connected to the second pulverized fuel pipes and disposed on the furnace rear wall.   
   
   
       8 . The pulverized coal combustion boiler according to  claim 1 , further comprising
 controllers are arranged on the pulverized fuel pipes to control the coal feed rates of the pulverized coal supplied from each of the mills to the burners.   
   
   
       9 . The pulverized coal combustion boiler according to  claim 1 , wherein
 the plurality of mills is arranged on both sides of the furnace sidewall connecting the furnace front wall and the furnace rear wall for constituting the furnace.   
   
   
       10 . The pulverized coal combustion boiler according to  claim 9 , wherein
 the plurality of mills are separately arranged on both sides of the furnace sidewall.   
   
   
       11 . The pulverized coal combustion boiler according to  claim 9 , wherein
 the plurality of mills are arranged on one side of the furnace sidewall.   
   
   
       12 . A pulverized coal combustion boiler comprising:
 a furnace;   a plurality of water pipes arranged on the furnace such as to form a water pipe wall of the furnace;   a furnace front wall and a furnace rear wall facing the furnace front wall to form the water pipe wall of the furnace having the water pipes;   a plurality of burners arranged on the furnace front wall and the furnace rear wall for supplying pulverized coal into the furnace;   a plurality of mills for pulverizing coal fuel to produce the pulverized coal; and   pulverized fuel pipes arranged for supplying the pulverized coal produced by the mills to the plurality of burners, characterized in that   the plurality of water pipes are arranged substantially vertical direction to constitute the water pipe wall of the furnace,   the plurality of burners are arranged to face each other on the water pipe walls of the furnace front wall and the furnace rear wall at positions of a predetermined height of the furnace,   the pulverized fuel pipes for supplying the pulverized coal from one of the plurality of mills to some of the plurality of burners facing each other at the positions of the predetermined height of the furnace are arranged on the water pipe wall surface to branch out into the furnace front wall and the furnace rear wall and connect to the some of the plurality of burners, and   other pulverized fuel pipes for supplying the pulverized coal from another one of the plurality of mills to the remaining plurality of mills facing each other at the positions of the predetermined height of the furnace are arranged on the water pipe wall surface to branch out into the furnace front wall and the furnace rear wall and connect to the remaining plurality of burners.   
   
   
       13 . The pulverized coal combustion boiler according to  claim 12 , wherein
 the pulverized fuel pipes for supplying the pulverized coal from one of the plurality of mills are arranged to branch out into the furnace front wall and the furnace rear wall and connect to burners, arranged to face each other, among the plurality of opposing burners arranged on the water pipe walls of the furnace front wall and the furnace real wall at the positions of the predetermined height of the furnace.   
   
   
       14 . The pulverized coal combustion boiler according to  claim 12 , wherein
 the pulverized fuel pipes for supplying the pulverized coal from one of the plurality of mills are arranged to branch out into one of the furnace front wall and the furnace rear wall and connect to the opposing burners arranged on one of the furnace front wall and the furnace rear wall, the burners being among the plurality of opposing burners arranged on the water pipe walls of the furnace front wall and the furnace rear wall at the positions of the predetermined height of the furnace, and   other pulverized fuel pipes for supplying the pulverized coal from another one of the plurality of mills are arranged to branch out into the other of the furnace front wall and the furnace rear wall and connect to the opposing burners arranged on the other of the furnace front wall and the furnace rear wall.   
   
   
       15 . The pulverized coal combustion boiler according to  claim 12 , wherein
 the plurality of burners arranged on the water pipe walls of the furnace front wall and the furnace rear wall at the position of the predetermined height of the furnace are arranged with an even number of burners.   
   
   
       16 . The pulverized coal combustion boiler according to  claim 12 , wherein
 the plurality of burners arranged on the water pipe walls of the furnace front wall and the furnace rear wall at the position of the predetermined height of the furnace are arranged with an odd number of burners.   
   
   
       17 . The pulverized coal combustion boiler according to  claim 12 , wherein
 the ratio of the amount of the pulverized coal supplied to the plurality of burners arranged on the furnace front wall of the furnace through the pulverized fuel pipes branched out from the mills to the amount of the pulverized coal supplied to the plurality of burners arranged on the furnace rear wall through the pulverized fuel pipes branched out from the mills is substantially equal to the ratio of the number of burners arranged on the water pipe walls of the furnace front wall at the same height of the furnace to the number of burners arranged on the water pipe walls of the furnace rear wall at the same height of the furnace.   
   
   
       18 . The pulverized coal combustion boiler according to  claim 12 , wherein
 the pulverized coal combustion boiler is operated so that the average in-pipe mass flow rate of the fluid flowing through the water pipes arranged substantially vertically in the furnace becomes 1000 kg/m 2  s to 400 kg/m 2  s at 50% boiler load.   
   
   
       19 . A power plant having a pulverized coal combustion boiler, the power plant providing 500 MW to 1100 MW electric power, the pulverized coal combustion boiler comprising:
 a furnace;   a plurality of water pipes arranged on the furnace such as to form a water pipe wall of the furnace;   a furnace front wall and a furnace rear wall facing the furnace front wall to form the water pipe wall of the furnace having the water pipes;   a plurality of burners arranged on the furnace front wall and the furnace rear wall for supplying pulverized coal fuel into the furnace;   a plurality of mills for pulverizing coal to produce the pulverized coal; and   pulverized fuel pipes arranged for supplying the pulverized coal produced by the mills to the plurality of burners, characterized in that   the plurality of water pipes are arranged substantially vertical direction to constitute the water pipe wall of the furnace,   the plurality of burners are arranged to face each other on the water pipe walls of the furnace front wall and the furnace rear wall at positions of a predetermined height of the furnace,   the pulverized fuel pipes for supplying the pulverized coal from one of the plurality of mills to some of the plurality of burners facing each other at the positions of the predetermined height of the furnace are arranged on the water pipe wall surface to branch out into the furnace front wall and the furnace rear wall and connect to the some of the plurality of burners,   other pulverized fuel pipes for supplying the pulverized coal from another one of the plurality of mills to the remaining plurality of mills facing each other at the positions of the predetermined height of the furnace are arranged on the water pipe wall surface to branch out into the furnace front wall and the furnace rear wall and connect to the remaining plurality of burners; and   at least one of an air heater, an electrostatic precipitator, and a bag filter are disposed at the downstream of the pulverized coal combustion boiler for flowing down an exhaust gas discharged from the pulverized coal combustion boiler.