JP6188658B2 - Combustion burner and boiler - Google Patents

Description

  The present invention relates to a combustion burner that mixes and burns solid fuel and air, and a boiler that generates steam from combustion gas generated by the combustion burner.

  Conventional coal-fired boilers have a hollow furnace that is installed in a vertical direction, and a plurality of combustion burners are arranged on the furnace wall along the circumferential direction and arranged in multiple stages in the vertical direction. ing. The combustion burner is supplied with a mixture of pulverized coal (fuel) obtained by pulverizing coal and primary air (carrier air), and also supplied with high-temperature secondary air. The mixture and secondary air are supplied to the combustion burner. Is blown into the furnace to form a flame that can be burned in the furnace. This furnace has a flue connected to the top, and this flue is provided with a superheater, reheater, economizer, etc. for recovering the heat of exhaust gas, and it was generated by combustion in the furnace. Heat exchange is performed between the exhaust gas and water, and steam can be generated.

  As a combustion burner applied to such a coal fired boiler, there is an internal combustion type burner, which is described, for example, in the following patent document. The combustor burner described in Patent Document 1 is obtained by dividing the inside of the burner into a plurality of stages and providing a plasma generator and a curved plate. The combustor burner described in Patent Document 2 is provided with a plurality of pre-ignition conduits in a conduit and a pre-ignition source in an upstream pre-ignition conduit.

Special table 2011-513694 gazette Special table 2014-501378 gazette

  As described above, the internal combustion burner is provided with a plurality of stepwise internal combustion chambers, ignited by the pre-ignition source for the pulverized coal supplied to the first internal combustion chamber, and then in the subsequent combustion chambers. It is intended to ignite and burn. For this reason, in the region where the heat load inside the burner is high, combustion is performed in stages, so that unburned parts can be reduced, and NOx generation can be reduced by reducing the air supplied to the burner part. However, in the internal combustion type burner, in order to ignite in the first combustion chamber, it is necessary to always keep the pre-ignition source arranged in this combustion chamber in an operating state during operation of the boiler. Therefore, when an oil burner or a gas burner is used as a pre-ignition source, the consumption of fuel that is more expensive than coal increases. In addition, when plasma is used as the pre-ignition source, the power consumption for generating plasma increases, and the plasma electrode is exhausted so that the durability is lowered.

  The present invention solves the above-described problems, and provides a combustion burner and a boiler capable of reducing the operating cost by reducing the use frequency of the ignition source by improving the ignitability in the internal combustion chamber. For the purpose.

  In order to achieve the above object, a combustion burner of the present invention comprises a fuel nozzle capable of ejecting a fuel gas in which solid fuel and combustion air are mixed, and a main combustion chamber having a cylindrical shape provided in the fuel nozzle. An ignition source provided in the main combustion chamber, a guide member capable of introducing the fuel gas flowing in the fuel nozzle into the main combustion chamber, and a position of the guide member according to a combustion state in the main combustion chamber And a control device for adjustment.

  Therefore, when the fuel gas flowing through the fuel nozzle is introduced into the main combustion chamber, the fuel gas is ignited and burned by the ignition source, and the flame is ejected from the tip of the fuel nozzle. At this time, the control device can positively introduce the solid fuel in the fuel gas into the main combustion chamber by adjusting the position of the guide member according to the combustion state in the main combustion chamber. The ignitability in the main combustion chamber is improved. As a result, the ignitability in the main combustion chamber is improved, so that the frequency of use of the ignition source can be reduced and the operating cost can be reduced.

  In the combustion burner of the present invention, a temperature measuring device for measuring the temperature of the main combustion chamber is provided, and the control device decreases the output of the ignition source as the temperature of the main combustion chamber increases. It is said.

  Therefore, when the temperature of the main combustion chamber rises, the ignitability in the main combustion chamber improves, so the output of the ignition source can be reduced, and the use frequency of the ignition source can be reduced to improve durability. In addition, the operating cost can be reduced.

  In the combustion burner of the present invention, the control device stops the ignition source when the temperature of the main combustion chamber becomes equal to or higher than a preset upper limit temperature.

  Therefore, when the temperature of the main combustion chamber exceeds the upper limit temperature, sufficient ignition performance is secured in the main combustion chamber, so that the ignition source can be stopped and the use frequency of the ignition source is reduced to improve durability. In addition, the operating cost can be reduced.

  In the combustion burner according to the present invention, the control device may position the guide member so that the amount of solid fuel introduced into the main combustion chamber increases when the temperature of the main combustion chamber is equal to or lower than a preset lower limit temperature. It is characterized by adjusting.

  Therefore, when the temperature of the main combustion chamber falls below the lower limit temperature, the amount of solid fuel introduced into the main combustion chamber is increased by adjusting the position of the guide member. Can form a perfect flame.

  The combustion burner according to the present invention is characterized in that a flame holder that forms a circulating flow that circulates axially is provided at the downstream end in the flow direction of the fuel gas in the main combustion chamber.

  Therefore, the fuel gas flowing in the main combustion chamber forms a circulating flow that circulates to the axial center side by the flame holder, and the ignitability in the main combustion chamber can be improved.

  In the combustion burner of the present invention, a fireproof member is provided on the inner wall surface of the main combustion chamber.

  Therefore, by providing a refractory member on the inner wall surface of the main combustion chamber, the temperature in the main combustion chamber can be raised, and the ignitability can be improved.

  In the combustion burner of the present invention, a sub-combustion chamber having a cylindrical shape is provided outside the downstream end portion in the fuel gas flow direction in the main combustion chamber so as to overlap with a predetermined gap, and the main combustion chamber and the The auxiliary combustion chamber is arranged at the center position of the fuel nozzle.

  Therefore, the ignitability can be improved by providing a sub-combustion chamber on the downstream side of the main combustion chamber and disposing the main combustion chamber and the sub-combustion chamber at the center position of the fuel nozzle.

  In the combustion burner of the present invention, the fuel nozzle is disposed along a horizontal direction, and an upper end portion of a solid fuel supply pipe disposed along a vertical direction is connected to a base end portion. In the main combustion chamber, the fuel gas is arranged on the upstream side in the flow direction and on the upper side in the vertical direction from the main combustion chamber.

  Therefore, since the solid fuel in the fuel gas flowing from the solid fuel supply pipe to the fuel nozzle flows biased above the fuel nozzle due to the centrifugal force, the solid fuel is efficiently burned by arranging the guide member at this position. It can be introduced indoors.

  In the combustion burner according to the present invention, the fuel nozzle and the main combustion chamber have a rectangular tube shape.

  Therefore, a stable flame can be formed by making the fuel nozzle and the main combustion chamber into a square cylinder shape.

  Further, the boiler of the present invention has a furnace having a hollow shape and installed in the vertical direction, a combustion apparatus having the combustion burner, and a flue for recovering heat from the exhaust gas generated in the furnace. It is characterized by this.

  Therefore, by improving the ignitability in the main combustion chamber in the combustion burner, the use frequency of the ignition source can be reduced, and the operating cost can be reduced.

  According to the combustion burner and boiler of the present invention, a guide member capable of introducing the fuel gas flowing in the fuel nozzle into the main combustion chamber is provided, and the position of the guide member is adjusted according to the combustion state in the main combustion chamber. The solid fuel in the fuel gas can be actively introduced into the main combustion chamber by the guide member, the ignitability in the main combustion chamber can be improved, the frequency of use of the ignition source can be reduced, and the operating cost can be reduced. be able to.

FIG. 1 is a schematic diagram illustrating a combustion burner according to the first embodiment. FIG. 2 is a schematic front view of the combustion burner. FIG. 3 is a schematic view of a combustion burner representing an activated state. FIG. 4 is a schematic configuration diagram illustrating the coal-fired boiler according to the first embodiment. FIG. 5 is a plan view of a combustion burner in a coal fired boiler. FIG. 6 is a schematic diagram illustrating a combustion burner according to the second embodiment. FIG. 7 is a schematic front view of the combustion burner. FIG. 8 is a schematic diagram illustrating a combustion burner according to the third embodiment. FIG. 9 is a schematic diagram illustrating a combustion burner according to the fourth embodiment.

  Exemplary embodiments of a combustion burner and a boiler according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

[First Embodiment]
FIG. 4 is a schematic configuration diagram illustrating the coal burning boiler according to the first embodiment, and FIG. 5 is a plan view of a combustion burner in the coal burning boiler.

  The boiler according to the first embodiment uses pulverized coal obtained by pulverizing coal (bituminous coal, subbituminous coal, etc.) as pulverized fuel (solid fuel), burns the pulverized coal with a combustion burner, and recovers heat generated by the combustion. It is a pulverized coal fired boiler that can.

  In this 1st Embodiment, as shown in FIG. 4, the coal burning boiler 10 is a conventional boiler, Comprising: The furnace 11 and the combustion apparatus 12 are provided. The furnace 11 has a rectangular hollow shape and is installed along the vertical direction. The furnace wall constituting the furnace 11 is constituted by a heat transfer tube.

  The combustion device 12 is provided in a lower part of a furnace wall (heat transfer tube) constituting the furnace 11. This combustion apparatus 12 has a plurality of combustion burners 21, 22, 23, 24, 25 mounted on the furnace wall. And the combustion apparatus 12 is arrange | positioned as 5 sets along the vertical direction, ie, 5 steps | paragraphs, as one set in which the four combustion burners were arrange | positioned at equal intervals along the circumferential direction. The combustion burners 21, 22, 23, 24 and 25 are a CCF (Circular Corner Filling) combustion system, and the shape of the furnace 11, the number of combustion burners in one stage, and the number of stages are limited to this embodiment. It is not a thing.

  Each combustion burner 21, 22, 23, 24, 25 is connected to a pulverized coal machine (mill) 31, 32, 33, 34, 35 via a pulverized coal supply pipe 26, 27, 28, 29, 30. . Although not shown, the pulverized coal machines 31, 32, 33, 34, and 35 are supported in a housing so that the pulverization table can be driven to rotate with a rotation axis along the vertical direction, and a plurality of pulverizations are provided above the pulverization table. A roller is configured to be rotatably supported in conjunction with the rotation of the grinding table. Accordingly, when coal is introduced between a plurality of crushing rollers and a crushing table, the pulverized coal supplied to the pulverized coal supply pipe 26 is pulverized to a predetermined size and classified by transporting air (primary air). 27, 28, 29, 30 can be supplied to the combustion burners 21, 22, 23, 24, 25.

  In the furnace 11, a wind box 36 is provided at a mounting position of each combustion burner 21, 22, 23, 24, 25, and one end portion of an air duct 37 is connected to the wind box 36. Is equipped with a blower 38 at the other end. Therefore, the combustion air (secondary air) sent by the blower 38 is supplied from the air duct 37 to the wind box 36 and supplied from the wind box 36 to the combustion burners 21, 22, 23, 24, 25. it can.

  Here, although the combustion apparatus 12 is demonstrated in detail, since each combustion burner 21, 22, 23, 24, 25 which comprises this combustion apparatus 12 has comprised the substantially the same structure, it is located in the uppermost stage. Only the combustion burner 21 will be described.

  As shown in FIG. 5, the combustion burner 21 includes combustion burners 21 a, 21 b, 21 c, and 21 d provided at four corners in the furnace 11. Each combustion burner 21a, 21b, 21c, 21d is connected to each branch pipe 26a, 26b, 26c, 26d branched from the pulverized coal supply pipe 26, and each branch pipe 37a, 37b, 37c branched from the air duct 37. , 37d are connected.

  Therefore, each combustion burner 21a, 21b, 21c, 21d at each corner of the furnace 11 blows into the furnace 11 a pulverized fuel mixture (fuel gas) in which pulverized coal and carrier air are mixed, Combustion air is blown outside the pulverized fuel mixture. Then, by igniting the pulverized fuel mixture from each combustion burner 21a, 21b, 21c, 21d, four flames F1, F2, F3, F4 can be formed, and this flame F1, F2, F3, F4. Is a flame swirl flow swirling counterclockwise as viewed from above the furnace 11 (in FIG. 5).

  Further, as shown in FIG. 4, the furnace 11 is provided with an additional combustion air supply device 41 at the upper stage of the combustion device 12. The additional combustion air supply device 41 has a plurality of additional combustion air nozzles 42 attached to the furnace wall 11a. The additional combustion air nozzles 42 are arranged as four sets at equal intervals along the circumferential direction, and one set, ie, one stage, is arranged along the vertical direction. That is, the additional combustion air supply device 41 (additional combustion air nozzle 42) is disposed above the mounting position of the combustion burner 21 in the furnace 11. The additional combustion air supply device 41 blows in additional combustion air (Over Fire Air) into the furnace 11. The additional combustion air nozzle 42 is connected to the end of the first branch air duct 43 branched from the air duct 37.

  Therefore, the combustion air sent by the blower 38 can be supplied from the first branch air duct 43 to the additional combustion air nozzle 42. Further, the additional combustion air nozzle 42 can blow additional combustion air above the pulverized fuel mixture blown by the combustion burners 21, 22, 23, 24, 25.

  The furnace 11 is provided with an additional air supply device 51 above the combustion device 12 and the additional combustion air supply device 41. The additional air supply device 51 has a plurality of additional air nozzles 52 mounted on the furnace wall 11a. One set of the additional air nozzles 52 arranged at equal intervals along the circumferential direction, that is, one stage is arranged. In other words, the additional air supply device 51 (additional air nozzle 52) is disposed above the mounting position of the combustion burner 21 in the furnace 11 by a predetermined distance. The additional air supply device 51 blows additional air (Additional Air) into the furnace 11. That is, the additional air nozzle 52 is composed of a plurality of additional air nozzles provided at four corners in the furnace 11, similar to the combustion burners 21, 22, 23, 24, 25, and is similar to the flame swirl flow. An additional air swirl is formed. The additional air nozzle 52 is connected to the end of a second branch air duct 53 branched from the air duct 37.

  Therefore, the combustion air sent by the blower 38 can be supplied from the second branch air duct 53 to the additional air nozzle 52. The additional air nozzle 52 can blow additional air above the additional combustion air blown by the additional combustion air nozzle 42.

  As described above, the combustion burners 21, 22, 23, 24, and 25 are flames by blowing pulverized fuel mixture (fuel gas) mixed with pulverized coal and carrier air and secondary air into the furnace 11. A swirling flow can be formed. The additional combustion air nozzle 42 can blow additional combustion air into the furnace 11 at the upper stage of the combustion burners 21, 22, 23, 24, 25. Further, the additional air nozzle 52 can blow additional air into the furnace 11 above the additional combustion air nozzle 42.

  The furnace 11 has a flue 70 connected to the upper portion thereof, and superheaters (superheaters) 71, 72, 73 and a reheater (reheater) 74 for recovering the heat of the exhaust gas. 75, economizers 76 and 77, and heat exchange is performed between the exhaust gas generated by the combustion in the furnace 11 and water.

  The flue 70 is connected to a gas duct 78 to which the exhaust gas subjected to heat exchange is discharged downstream. This gas duct 78 is provided with an air heater 79 between the air duct 37 and performs heat exchange between the air flowing through the air duct 37 and the exhaust gas flowing through the gas duct 78, and the combustion burners 21, 22, 23, 24, The temperature of the combustion air supplied to 25 can be raised.

  Although not shown, the gas duct 78 is provided with a denitration device, an electrostatic precipitator, an induction blower, and a desulfurization device, and a chimney is provided at the downstream end.

  In the coal fired boiler 10 configured as described above, the internal combustion type combustion burner is applied to the combustion burners 21, 22, 23, 24, and 25. FIG. 1 is a schematic view showing a combustion burner according to the first embodiment, FIG. 2 is a schematic front view of the combustion burner, and FIG. 3 is a schematic view of the combustion burner showing an activated state.

  As shown in FIGS. 1 and 2, the combustion burner 21 (21a, 21b, 21c, 21d) includes a fuel nozzle 101, a main combustion chamber 102, auxiliary combustion chambers 103, 104, an ignition source 105, and a guide member. 106, 107.

  The fuel nozzle 101 has a rectangular tube shape and can eject a finely divided fuel mixture obtained by mixing finely divided fuel and combustion air. The fuel nozzle 101 is disposed along the horizontal direction, and the upper end portion of the pulverized coal supply pipe 26 disposed along the vertical direction is connected to the base end portion. In this case, since the pulverized coal supply pipe 26 has a cylindrical shape, the pulverized coal supply pipe 26 is connected to the fuel nozzle 101 while its tip portion is deformed from a cylindrical shape to a square cylindrical shape.

  The main combustion chamber 102 has a rectangular cylinder shape smaller than the fuel nozzle 101, is disposed in the fuel nozzle 101, and is supported on the inner wall surface of the fuel nozzle 101 by a plurality of stays 111. The sub-combustion chamber 103 is smaller than the fuel nozzle 101 and has a rectangular cylinder shape larger than the main combustion chamber 102, is disposed in the fuel nozzle 101, and is supported on the inner wall surface of the fuel nozzle 101 by a plurality of stays 112. The sub-combustion chamber 104 is smaller than the fuel nozzle 101 and has a rectangular cylinder shape larger than the sub-combustion chamber 103, is disposed in the fuel nozzle 101, and is supported on the inner wall surface of the fuel nozzle 101 by a plurality of stays 113.

  The main combustion chamber 102 and the sub-combustion chambers 103 and 104 are arranged in series so as to partially overlap in the fuel nozzle 101 along the flow direction of the pulverized fuel mixture. That is, the auxiliary combustion chamber 103 is provided outside the downstream end of the main combustion chamber 102 in the flow direction of the pulverized fuel mixture so as to overlap with a predetermined gap. A sub-combustion chamber 104 is provided outside the downstream end of the sub-combustion chamber 103 in the flow direction of the pulverized fuel mixture so as to overlap with a predetermined gap. The main combustion chamber 102 and the sub-combustion chambers 103 and 104 are disposed at the center position of the fuel nozzle 101, and the end of the sub-combustion chamber 104 is set at the same position as the tip of the fuel nozzle 101.

  The ignition source 105 passes through the wall portion of the fuel nozzle 101, and the tip portion is disposed in the main combustion chamber 102. In this case, it is desirable for the ignition source 105 to place the ignition plug at an upstream position in the fuel nozzle 101 in the flow direction of the pulverized fuel mixture. The ignition source 105 is, for example, an oil burner, a gas burner, a plasma ignition device, or the like, and can ignite the pulverized fuel mixture flowing in the main combustion chamber 102.

  The guide members 106 and 107 are for introducing the pulverized fuel mixture flowing in the fuel nozzle 101, particularly the pulverized fuel, into the main combustion chamber 102. The guide member 106 is disposed on the upstream side in the flow direction of the pulverized fuel mixture in the main combustion chamber 102 and on the upper side in the vertical direction from the main combustion chamber 102. On the other hand, the guide member 107 is disposed on the upstream side in the flow direction of the pulverized fuel mixture in the main combustion chamber 102 and on the lower side in the vertical direction from the main combustion chamber 102. The guide members 106 and 107 are arranged to face each other in the vertical direction.

  The guide members 106 and 107 have the same configuration. The guide members 106 and 107 are formed in a butterfly shape in which two plate members are fixed to the outer peripheral portions of the support shafts 121 and 122, and the support shafts 121 and 122 are rotatable on the left and right wall portions of the fuel nozzle 101. It is supported by. The support shafts 121 and 122 are drivingly connected to drive devices 123 and 124, and the guide members 106 and 107 can be rotated by the drive devices 123 and 124.

  The control device 125 can drive and control the drive devices 123 and 124, and can adjust the positions of the guide members 106 and 107, that is, the rotation angle, according to the combustion state in the main combustion chamber 102. In this case, the main combustion chamber 102 is provided with a temperature measuring device 126 on the inner wall surface on the downstream side in the flow direction of the pulverized fuel mixture, and the temperature measuring device 126 controls the measured temperature in the main combustion chamber 102. Output to the device 125. Then, the control device 125 drives and controls the drive devices 123 and 124 based on the temperature in the main combustion chamber 102 and adjusts the guide members 106 and 107 to the optimum angle. In other words, the control device 125 adjusts the angle of the guide members 106 and 107 based on the temperature in the main combustion chamber 102, so that the amount of the pulverized fuel mixture introduced into the main combustion chamber 102, that is, the pulverized fuel Adjust the amount.

  Specifically, the control device 125 decreases the output of the ignition source 105 as the temperature of the main combustion chamber 102 increases. Further, the control device 125 stops the ignition source 105 when the temperature of the main combustion chamber 102 becomes equal to or higher than a preset upper limit temperature. Further, the controller 125 guides the guide member 106 so that the amount of the fine fuel mixture (fine fuel) introduced into the main combustion chamber 102 increases when the temperature of the main combustion chamber 102 falls below a preset lower limit temperature. , 107 are adjusted.

  Here, the operation of the coal fired boiler 10 will be described.

  As shown in FIG. 4, when the pulverized coal machines 31, 32, 33, 34, 35 are driven, the pulverized pulverized coal together with the conveying air passes through the pulverized coal supply pipes 26, 27, 28, 29, 30 and the combustion burner 21. , 22, 23, 24, 25. Also, heated combustion air is supplied from the air duct 37 to the combustion burners 21, 22, 23, 24, 25 via the wind box 36. Further, the heated combustion air is supplied to the additional combustion air nozzle 42 and the additional air nozzle 52 by the branched air ducts 43 and 53 branched from the air duct 37.

  Then, the combustion burners 21, 22, 23, 24, 25 blow the pulverized fuel mixture mixture of pulverized coal and carrier air and the secondary air into the furnace 11, and ignite at this time to enter the combustion region A. A flame swirl can be formed.

  That is, when the combustion burners 21, 22, 23, 24, 25 are started, as shown in FIGS. 1 and 2, the control device 125 controls the drive devices 123, 124 to drive the guide members 106, 107. The angle is adjusted to be parallel to the axial direction of the fuel nozzle 101 (the flow direction of the pulverized fuel mixture). Then, the pulverized fuel mixture flows in the fuel nozzle 101 in the axial direction, and a part thereof enters the main combustion chamber 102. At this time, the ignition source 105 is operated to ignite the pulverized fuel mixture flowing in the main combustion chamber 102. Then, a flame is formed in the main combustion chamber 102, and this flame extends toward the auxiliary combustion chambers 103 and 104. The pulverized fuel mixture flowing in the fuel nozzle 101 in the axial direction enters the auxiliary combustion chamber 103 through the gap between the main combustion chamber 102 and the auxiliary combustion chamber 103 and enters the auxiliary combustion chamber 104 from between the auxiliary combustion chambers 103 and 104. Get in. Therefore, the pulverized fuel mixture flowing in the auxiliary combustion chambers 103 and 104 is ignited by the flame formed in the main combustion chamber 102. As a result, a flame can be ejected from the tip of the fuel nozzle 101.

  Thereafter, when the flame ejected from the tip of the fuel nozzle 101 is stabilized, the boiler 10 enters the normal operation mode. Then, as shown in FIGS. 2 and 3, the control device 125 controls the driving devices 123 and 124 to adjust the angle so that the guide members 106 and 107 face the main combustion chamber 102. Then, the pulverized fuel mixture enters the main combustion chamber 102 as the pulverized fuel flowing along the inner wall surface in the fuel nozzle 101 is guided by the guide members 106 and 107. Then, in the main combustion chamber 102, the concentration of the pulverized fuel in the pulverized fuel mixture increases, and the heat load increases to increase the combustion temperature and improve the ignitability.

  Therefore, the control device 125 decreases the output of the ignition source 105 as the temperature of the main combustion chamber 102 increases. Thereafter, the controller 125 stops the ignition source 105 when the temperature of the main combustion chamber 102 becomes equal to or higher than the upper limit temperature. As a result, the operating time of the ignition source 105 is shortened, energy for operating the ignition source 105 can be reduced, and the operating cost of the boiler 10 is reduced. Further, at this time, the control device 125 causes the guide member 106, the amount of the pulverized fuel mixture (the pulverized fuel) introduced into the main combustion chamber 102 to increase when the temperature of the main combustion chamber 102 becomes equal to or lower than the lower limit temperature. The angle of 107 is adjusted. In this case, when the boiler 10 is in the normal operation mode, the guide members 106 and 107 are rotated by half or only the guide member 106 is rotated, and the temperature of the main combustion chamber 102 becomes lower than the lower limit temperature. Then, the guide members 106 and 107 may be further rotated, or both guide members 106 and 107 may be rotated. Still, when the temperature of the main combustion chamber 102 does not rise, the ignition source 105 is operated.

  Further, as shown in FIG. 4, simultaneously with the combustion burners 21, 22, 23, 24, and 25 blowing the pulverized coal mixture into the furnace 11, the additional combustion air nozzle 42 blows in the additional combustion air into the furnace 11. Thereby, the combustion area | region A can be formed appropriately. In the furnace 11, when the pulverized fuel mixture, the secondary air, and the additional combustion air are burned to generate a flame swirl, and a flame swirl is generated in the combustion region A, the combustion gas (exhaust gas) swirls in the furnace 11. It rises while reaching the reduction region B.

  At this time, in the furnace 11, the combustion burners 21, 22, 23, 24, and 25 are set so that the supply amount of air is less than the theoretical air amount with respect to the supply amount of pulverized coal. The reduction region B above A is maintained in a reducing atmosphere. Therefore, NOx generated by the combustion of pulverized coal is reduced in this reduction region B.

  The additional air nozzle 52 blows additional air above the reduction region B of the furnace 11. Then, in the combustion completion region C, the exhaust gas reacts with the additional air, whereby the oxidative combustion of the pulverized coal is completed, and the amount of NOx generated by the combustion of the pulverized coal is reduced.

  The water supplied from a water supply pump (not shown) is preheated by the economizers 76 and 77 and then heated while being supplied to a steam drum (not shown) and supplied to each water pipe (not shown) on the furnace wall. Then, it becomes saturated steam and is sent to a steam drum (not shown). Further, saturated steam of a steam drum (not shown) is introduced into the superheaters 71, 72, 73 and is heated by the combustion gas. The superheated steam generated by the superheaters 71, 72, 73 is supplied to a power plant (not shown) such as a turbine. Further, the steam taken out in the middle of the expansion process in the turbine is introduced into the reheaters 74 and 75, overheated again, and returned to the turbine. In addition, although the furnace 11 was demonstrated as a drum type | mold (steam drum), it is not limited to this structure.

  Thereafter, the exhaust gas that has passed through the economizers 76 and 77 of the flue 70 is subjected to removal of harmful substances such as NOx by a catalyst in a denitration device (not shown) in a gas duct 78, and particulate matter is removed by an electric dust collector. After the sulfur content is removed by the desulfurization device, it is discharged from the chimney into the atmosphere.

  As described above, in the combustion burner according to the first embodiment, the fuel nozzle 101 capable of injecting a pulverized fuel mixture obtained by mixing pulverized fuel and combustion air, and a cylindrical shape provided in the fuel nozzle 101. Combustion chamber 102, ignition source 105 provided in main combustion chamber 102, guide members 106 and 107 capable of introducing pulverized fuel mixture flowing in fuel nozzle 101 into main combustion chamber 102, and combustion in main combustion chamber 102 A control device 125 that adjusts the angles of the guide members 106 and 107 according to the state is provided.

  Therefore, when the pulverized fuel mixture flowing in the fuel nozzle 101 is introduced into the main combustion chamber 102, the pulverized fuel mixture is ignited and burned by the ignition source 105, and the flame is ejected from the tip of the fuel nozzle 101. . At this time, the control device 125 adjusts the positions of the guide members 106 and 107 in accordance with the combustion state in the main combustion chamber 102, so that the pulverized fuel in the pulverized fuel mixture is actively fed by the guide members 106 and 107. Can be introduced into the main combustion chamber 102, and the ignitability in the main combustion chamber 102 is improved. As a result, the ignitability in the main combustion chamber 102 is improved, so that the frequency of use of the ignition source 105 can be reduced, and the operating cost can be reduced.

  In the combustion burner of the first embodiment, a temperature measuring device 126 that measures the temperature of the main combustion chamber 102 is provided, and the control device 125 decreases the output of the ignition source 105 as the temperature of the main combustion chamber 102 increases. Therefore, when the temperature of the main combustion chamber 102 rises, the ignitability in the main combustion chamber 102 is improved, so that the output of the ignition source 105 can be reduced, the use frequency of the ignition source 105 is reduced, and durability is improved. This can improve the operation cost.

  In the combustion burner of the first embodiment, the control device 125 stops the ignition source 105 when the temperature of the main combustion chamber 102 becomes equal to or higher than the upper limit temperature. Therefore, when the temperature of the main combustion chamber 102 becomes equal to or higher than the upper limit temperature, sufficient ignition performance is secured in the main combustion chamber 102, so that the ignition source 105 can be stopped and the frequency of use of the ignition source 105 is reduced. The durability can be improved and the operating cost can be reduced.

  In the combustion burner of the first embodiment, the control device 125 determines the angle of the guide members 106 and 107 so that the amount of pulverized fuel introduced into the main combustion chamber 102 increases when the temperature of the main combustion chamber 102 becomes lower than the lower limit temperature. Adjust. Therefore, when the temperature of the main combustion chamber 102 becomes equal to or lower than the lower limit temperature, the amount of fine fuel introduced into the main combustion chamber 102 is increased by adjusting the angles of the guide members 106 and 107. An appropriate flame can be formed by increasing the ignitability.

  In the combustion burner of the first embodiment, the secondary combustion chambers 103 and 104 having a cylindrical shape are provided outside the downstream end in the flow direction of the pulverized fuel mixture in the main combustion chamber 102 so as to overlap with a predetermined gap, The main combustion chamber 102 and the sub-combustion chambers 103 and 104 are arranged at the center position of the fuel nozzle 101. Therefore, the pulverized fuel mixture can be appropriately introduced into the main combustion chamber 102 and the sub-combustion chambers 103 and 104 to improve the ignitability.

  In the combustion burner of the first embodiment, the fuel nozzle 101 is disposed along the horizontal direction, the upper end portion of the pulverized coal supply pipe 26 disposed along the vertical direction is connected to the base end portion, and the guide member 106 is connected. Is disposed upstream of the main combustion chamber 102 in the flow direction of the pulverized fuel mixture and above the main combustion chamber 102 in the vertical direction. The pulverized fuel in the pulverized fuel mixture flowing from the pulverized coal supply pipe 26 to the fuel nozzle 101 flows biased above the fuel nozzle 101 due to the centrifugal force. Therefore, by arranging the guide member 106 at this position, It can be efficiently introduced into the main combustion chamber 102.

  Moreover, in the boiler of 1st Embodiment, the furnace 11 which has a hollow shape and is installed along a perpendicular direction, the combustion apparatus 12 which has the combustion burners 21, 22, 23, 24, and 25, and a furnace 11 is provided with a flue 70 for recovering heat from the exhaust gas generated at 11. Therefore, by improving the ignitability in the main combustion chamber 102 in the combustion burners 21, 22, 23, 24, 25, the frequency of use of the ignition source 105 can be reduced, and the operating cost can be reduced.

[Second Embodiment]
FIG. 6 is a schematic view showing the combustion burner of the second embodiment, and FIG. 7 is a schematic front view of the combustion burner. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the second embodiment, as shown in FIGS. 6 and 7, the combustion burner 131 includes a fuel nozzle 101, a main combustion chamber 102, auxiliary combustion chambers 103 and 104, an ignition source 105, a guide member 106, 107.

  The fuel nozzle 101 can eject a pulverized fuel mixture obtained by mixing pulverized fuel and combustion air. The main combustion chamber 102 and the sub-combustion chambers 103 and 104 are arranged in the fuel nozzle 101, and are arranged in series so as to partially overlap in the flow direction of the pulverized fuel mixture. The ignition source 105 has a tip portion disposed in the main combustion chamber 102. The guide members 106 and 107 are for introducing the pulverized fuel mixture flowing in the fuel nozzle 101, particularly the pulverized fuel, into the main combustion chamber 102. The guide members 106 and 107 are arranged on the upstream side in the flow direction of the pulverized fuel mixture in the main combustion chamber 102 and on the upper and lower sides in the vertical direction from the main combustion chamber 102. The guide members 106 and 107 can be rotated by driving devices 123 and 124.

  In the present embodiment, a flame holder 132 is provided at the downstream end of the main combustion chamber 102 in the flow direction of the pulverized fuel mixture. The flame stabilizer 132 has a ring shape, the base end is fixed to the end of the main combustion chamber 102, the tip is downstream of the flow direction of the pulverized fuel mixture, and the radial direction in the main combustion chamber 102 It is extended so that it may incline outside. The flame holder 132 forms a circulating flow that circulates the flow of the pulverized fuel mixture flowing outside the main combustion chamber 102 toward the axial center.

  In addition, a flame holder 133 is provided at the downstream end of the auxiliary combustion chamber 103 in the flow direction of the pulverized fuel mixture. The flame holder 133 has a ring shape that is substantially the same shape as the flame holder 132, the base end is fixed to the end of the sub-combustion chamber 103, and the tip is downstream of the flow direction of the pulverized fuel mixture. And it is extended so that it may incline to the outer side of the radial direction in the subcombustion chamber 103. The flame holder 133 forms a circulating flow that circulates the flow of the pulverized fuel mixture flowing outside the auxiliary combustion chamber 103 toward the axial center.

  The control device 125 can drive and control the drive devices 123 and 124, and can adjust the angles of the guide members 106 and 107 according to the combustion state in the main combustion chamber 102. Specifically, the control device 125 drives and controls the drive devices 123 and 124 based on the temperature in the main combustion chamber 102 measured by the temperature measuring device 126, and adjusts the guide members 106 and 107 to the optimum angle. The amount of the fine fuel mixture (fine fuel) introduced into the main combustion chamber 102 is adjusted.

  Therefore, when the boiler is operated in the normal operation mode, the control device 125 controls the drive devices 123 and 124 to adjust the angle so that the guide members 106 and 107 face the main combustion chamber 102 side. Then, the pulverized fuel mixture enters the main combustion chamber 102 as the pulverized fuel flowing along the inner wall surface in the fuel nozzle 101 is guided by the guide members 106 and 107. Then, in the main combustion chamber 102, the concentration of the pulverized fuel in the pulverized fuel mixture increases, and the heat load increases to increase the combustion temperature and improve the ignitability.

  At this time, in the main combustion chamber 102, a circulation flow is formed in which the flow of the pulverized fuel mixture flowing outside by the flame stabilizer 132 circulates to the axial center side, and the ignitability in the sub-combustion chamber 103 is improved. Further, in the auxiliary combustion chamber 103, a circulation flow is formed in which the flow of the pulverized fuel mixture flowing outside the auxiliary combustion chamber 103 is circulated to the axial center side by the flame holder 133, and the ignitability in the auxiliary combustion chamber 104 is improved. Get better.

  Then, not only the main combustion chamber 102 but also the temperatures of the sub-combustion chambers 103 and 104 rise early, and the control device 125 decreases the output of the ignition source 105 as the temperature of the main combustion chamber 102 rises. The ignition source 105 can be stopped. As a result, the operating time of the ignition source 105 is shortened, energy for operating the ignition source 105 can be reduced, and the operating cost of the boiler 10 is reduced.

  As described above, in the combustion burner according to the second embodiment, the fuel nozzle 101 capable of injecting a pulverized fuel mixture obtained by mixing pulverized fuel and combustion air, and a cylindrical shape provided in the fuel nozzle 101. Combustion chamber 102, ignition source 105 provided in main combustion chamber 102, guide members 106 and 107 capable of introducing pulverized fuel mixture flowing in fuel nozzle 101 into main combustion chamber 102, and combustion in main combustion chamber 102 A control device 125 that adjusts the angle of the guide members 106 and 107 according to the state, and a flame holder 132 that is provided at the ends of the main combustion chamber 102 and the sub-combustion chamber 103 to form a circulating flow that circulates toward the axial center. 133 are provided.

  Therefore, the pulverized fuel mixture flowing in the main combustion chamber 102 forms a circulating flow that circulates to the axial center side by the flame stabilizer 132, and the ignitability in the main combustion chamber 102 is improved. In addition, the pulverized fuel mixture flowing in the auxiliary combustion chamber 103 forms a circulating flow that circulates to the axial center side by the flame stabilizer 133, and the ignitability in the auxiliary combustion chamber 103 is improved. Therefore, by improving the ignitability in the main combustion chamber 102 and the sub-combustion chamber 103, the output of the ignition source 105 can be reduced or stopped early, and the use frequency of the ignition source 105 is reduced. Thus, the operation cost can be reduced.

[Third Embodiment]
FIG. 8 is a schematic diagram illustrating a combustion burner according to the third embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the third embodiment, as shown in FIG. 8, the combustion burner 141 includes a fuel nozzle 101, a main combustion chamber 102, auxiliary combustion chambers 103 and 104, an ignition source 105, and guide members 106 and 107. Have.

  The fuel nozzle 101 can eject a pulverized fuel mixture obtained by mixing pulverized fuel and combustion air. The main combustion chamber 102 and the sub-combustion chambers 103 and 104 are arranged in the fuel nozzle 101, and are arranged in series so as to partially overlap in the flow direction of the pulverized fuel mixture. The ignition source 105 has a tip portion disposed in the main combustion chamber 102. The guide members 106 and 107 are for introducing the pulverized fuel mixture flowing in the fuel nozzle 101, particularly the pulverized fuel, into the main combustion chamber 102. The guide members 106 and 107 are arranged on the upstream side in the flow direction of the pulverized fuel mixture in the main combustion chamber 102 and on the upper and lower sides in the vertical direction from the main combustion chamber 102. The guide members 106 and 107 can be rotated by driving devices 123 and 124.

In the present embodiment, a refractory member 142 is provided on the inner wall surface of the main combustion chamber 102. The refractory member 142 is made of silica (silicon dioxide / SiO ₂ ), refractory bricks, or the like, and has heat storage properties.

  Therefore, when the boiler is operated in the normal operation mode, the angles of the guide members 106 and 107 are adjusted so as to face the main combustion chamber 102 side. Then, the pulverized fuel mixture enters the main combustion chamber 102 as the pulverized fuel flowing along the inner wall surface in the fuel nozzle 101 is guided by the guide members 106 and 107. Then, in the main combustion chamber 102, the concentration of the pulverized fuel in the pulverized fuel mixture increases, and the heat load increases to increase the combustion temperature and improve the ignitability.

  Further, in the main combustion chamber 102, a refractory member 142 is provided on the inner wall surface, and the refractory member 142 stores the heat of the flame, so that the temperature in the main combustion chamber 102 rises and the ignitability is further improved. . Then, since the temperature of the main combustion chamber 102 rises to the upper limit temperature at an early stage, the control device 125 decreases the output of the ignition source 105 or stops the ignition source 105 as the temperature of the main combustion chamber 102 increases. You can do it. As a result, the operating time of the ignition source 105 is shortened, energy for operating the ignition source 105 can be reduced, and the operating cost of the boiler 10 is reduced.

  As described above, in the combustion burner of the third embodiment, the fuel nozzle 101 capable of injecting a pulverized fuel mixture obtained by mixing pulverized fuel and combustion air, and a cylindrical shape provided in the fuel nozzle 101. A combustion chamber 102, an ignition source 105 provided in the main combustion chamber 102, and guide members 106 and 107 capable of introducing the pulverized fuel mixture flowing in the fuel nozzle 101 into the main combustion chamber 102 are provided. A fireproof member 142 is provided on the inner wall surface.

  Therefore, when a flame is formed in the main combustion chamber 102, the refractory member 142 stores the heat of the flame, so that the ignitability in the main combustion chamber 102 is improved. Therefore, by improving the ignitability in the main combustion chamber 102, the output of the ignition source 105 can be reduced or stopped at an early stage, and the use frequency of the ignition source 105 is reduced, thereby reducing the operating cost. Can be reduced.

  In this embodiment, the refractory member 142 is provided on the inner wall surface of the main combustion chamber 102, but a refractory member may be provided on the inner wall surfaces of the auxiliary combustion chambers 103 and 104.

  In each of the above-described embodiments, the guide members 106 and 107 are provided above and below the main combustion chamber 102. However, only one of the guide members 106 and 107 may be provided with respect to the main combustion chamber 102. They may be provided on the left and right, and may be corners.

[Fourth Embodiment]
FIG. 9 is a schematic diagram illustrating a combustion burner according to the fourth embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the fourth embodiment, as shown in FIG. 9, the combustion burner 151 includes a fuel nozzle 101, a main combustion chamber 102, auxiliary combustion chambers 103 and 104, an ignition source 105, and a guide member 152. ing.

  The fuel nozzle 101 can eject a pulverized fuel mixture obtained by mixing pulverized fuel and combustion air. The main combustion chamber 102 and the sub-combustion chambers 103 and 104 are arranged in the fuel nozzle 101, and are arranged in series so as to partially overlap in the flow direction of the pulverized fuel mixture. The ignition source 105 has a tip portion disposed in the main combustion chamber 102.

  The guide member 152 is disposed on the upstream side in the flow direction of the pulverized fuel mixture in the main combustion chamber 102 and on the upper side in the vertical direction from the main combustion chamber 102. The guide member 152 is configured to have a flat plate shape in which a plate material is fixed to the support shaft 153, and the support shaft 153 is supported by the wall portion at the upper part of the fuel nozzle 101 via the bracket 154 so as to be rotatable up and down. . The support shaft 153 is drivingly connected to a driving device 155, and the driving device 155 can rotate the guide member 152.

  A control device (not shown) can drive and control the drive device 155 and can adjust the angle of the guide member 152 according to the combustion state in the main combustion chamber 102. Specifically, the control device drives and controls the drive device 155 based on the temperature in the main combustion chamber 102, and adjusts the guide member 152 to the optimum angle, so that the pulverized fuel mixture introduced into the main combustion chamber 102 is obtained. Adjust the amount of (fine powder fuel).

  Note that the control of the guide member 152 by the control device is the same as in each of the above-described embodiments, and thus description thereof is omitted.

  As described above, in the combustion burner of the fourth embodiment, the fuel nozzle 101 capable of ejecting a fine fuel mixture obtained by mixing fine fuel and combustion air, and a main body having a cylindrical shape provided in the fuel nozzle 101. Combustion chamber 102, ignition source 105 provided in main combustion chamber 102, guide member 152 capable of introducing pulverized fuel mixture flowing in fuel nozzle 101 into main combustion chamber 102, and combustion state in main combustion chamber 102 Accordingly, a control device for adjusting the angle of the guide member 152 is provided.

  Therefore, the control device adjusts the angle of the guide member 152 according to the combustion state in the main combustion chamber 102, so that the pulverized fuel in the pulverized fuel mixture is actively introduced into the main combustion chamber 102 by the guide member 152. Thus, the ignitability in the main combustion chamber 102 is improved. As a result, the ignitability in the main combustion chamber 102 is improved, so that the frequency of use of the ignition source 105 can be reduced, and the operating cost can be reduced.

  In the above-described embodiment, the fuel nozzle 101, the main combustion chamber 102, and the auxiliary combustion chambers 103 and 104 have a rectangular tube shape. However, the present invention is not limited to this shape. It is good also as a shape, an elliptical shape, etc.

  In the above-described embodiment, the butterfly-shaped guide members 106 and 107 and the flat plate-shaped guide member 152 are applied. However, the shape is not limited to this, and the fuel gas flowing in the fuel nozzle 101 is mainly used. Any shape that can be introduced into the combustion chamber 102 may be used.

  In the above-described embodiment, the main combustion chamber 102 and the two sub-combustion chambers 103 and 104 are provided in the fuel nozzle 101. However, the present invention is not limited to this configuration. One or three or more auxiliary combustion chambers may be provided.

  In the above-described embodiment, the fuel nozzle arranged in the horizontal direction is connected to the solid fuel supply pipe arranged in the vertical direction. However, the solid fuel supply pipe is arranged in the horizontal direction or the fuel nozzle is inclined. Or may be arranged. Moreover, although the form of the combustion burner in the boiler is a CCF combustion system, it may be a CUF (Circular Ultra Fire) combustion system.

  In the above-described embodiment, the boiler of the present invention is a coal-fired boiler. However, the fuel may be a boiler using biomass or petroleum coke, or may be applied to an oil-fired boiler.

DESCRIPTION OF SYMBOLS 10 Coal-fired boiler 11 Furnace 12 Combustion device 21, 22, 23, 24, 25, 131, 141, 151 Combustion burner 26, 27, 28, 29, 30 Pulverized coal supply pipe (solid fuel supply pipe)
31, 32, 33, 34, 35 Pulverized coal machine 41 Additional combustion air supply device 51 Additional air supply device 70 Flue 101 Fuel nozzle 102 Main combustion chamber 103, 104 Subcombustion chamber 105 Ignition source 106, 107, 152 Guide member 123, 124, 155 Driving device 125 Control device 126 Temperature measuring device 132, 133 Flame holder 142 Fireproof member

Claims (11)

A fuel nozzle disposed along the horizontal direction and capable of ejecting a fuel gas mixed with solid fuel and combustion air;
A main combustion chamber having a cylindrical shape provided in the fuel nozzle;
An ignition source provided in the main combustion chamber;
A guide member capable of introducing the fuel gas into the main combustion chamber by adjusting the angle upstream of the flow direction of the fuel gas in the main combustion chamber in the fuel nozzle;
A control device for adjusting the position of the guide member from an angle parallel to the axial direction of the fuel nozzle to an angle toward the main combustion chamber according to a combustion state in the main combustion chamber ;
A combustion burner characterized by comprising:   The temperature measuring device for measuring the temperature of the main combustion chamber is provided, and the control device decreases the output of the ignition source as the temperature of the main combustion chamber increases. Burning burner.   The combustion burner according to claim 2, wherein the control device stops the ignition source when the temperature of the main combustion chamber becomes equal to or higher than a preset upper limit temperature.   The control device adjusts the position of the guide member so that the amount of solid fuel introduced into the main combustion chamber increases when the temperature of the main combustion chamber becomes equal to or lower than a preset lower limit temperature. The combustion burner according to any one of claims 1 to 3.   5. The flame holder for forming a circulating flow circulating in the axial center side is provided at a downstream end portion in a flow direction of the fuel gas in the main combustion chamber. 6. The combustion burner described in.   The combustion burner according to any one of claims 1 to 5, wherein a refractory member is provided on an inner wall surface of the main combustion chamber.   A sub-combustion chamber having a cylindrical shape is provided outside the downstream end portion of the main combustion chamber in the flow direction of the fuel gas so as to overlap with a predetermined gap, and the main combustion chamber and the sub-combustion chamber include the fuel The combustion burner according to any one of claims 1 to 6, wherein the combustion burner is arranged at a center position of the nozzle.   The fuel nozzle is disposed along a horizontal direction, and an upper end portion of a solid fuel supply pipe disposed along a vertical direction is connected to a base end portion, and the guide member is a fuel gas in the main combustion chamber. The combustion burner according to any one of claims 1 to 7, wherein the combustion burner is disposed upstream of the main combustion chamber and upstream of the main combustion chamber in the vertical direction.   The combustion burner according to any one of claims 1 to 8, wherein the fuel nozzle and the main combustion chamber have a rectangular tube shape. A furnace that is hollow and installed along the vertical direction;
A combustion apparatus having the combustion burner according to any one of claims 1 to 9,
A flue for recovering heat from the exhaust gas generated in the furnace;
The boiler characterized by having. A fuel nozzle disposed along the horizontal direction and capable of ejecting a fuel gas mixed with solid fuel and combustion air;
A main combustion chamber having a cylindrical shape provided in the fuel nozzle;
An ignition source provided in the main combustion chamber;
A guide member capable of introducing fuel gas into the main combustion chamber on the upstream side in the flow direction of fuel gas in the main combustion chamber in the fuel nozzle;
A control device for adjusting the position of the guide member according to the combustion state in the main combustion chamber;
Have
The fuel nozzle is disposed along a horizontal direction, and an upper end portion of a solid fuel supply pipe disposed along a vertical direction is connected to a base end portion, and the guide member is a fuel gas in the main combustion chamber. Is arranged upstream in the flow direction and above the main combustion chamber in the vertical direction.
Combustion burner characterized by that.

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