JP2015083893A - Boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve boiler efficiency of a boiler by reducing an unburned combustible content of a fuel.SOLUTION: A boiler includes: a furnace 11 having a hollow shape and installed along a vertical direction; first combustion burners 21, 22, 24, and 25 each of which can form a first flame swirl flow by blowing a first fuel gas into the furnace 11; and a second burner 23 that can form a second flame swirl flow smaller in diameter than the first flame swirl flow by blowing a second fuel gas, in which pulverized biomass and combustion air are mixed, into the furnace 11.

Description

  The present invention relates to a boiler that generates steam by burning biomass, coal, and air.

  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.

In recent years, CO ₂ emission reduction has been promoted from the viewpoint of global warming. In particular, fossil fuels such as coal and heavy oil are often used as fuel for power generation boilers. This fossil fuel causes global warming due to the problem of CO ₂ emissions, and from the viewpoint of global environmental conservation. Use is being regulated. Therefore, as an alternative to fossil fuels, the use of fuel using biomass has been promoted. Biomass is an organic substance resulting from photosynthesis, and includes biomass such as wood, vegetation, crops, and moss. By converting this biomass into fuel, the biomass can be effectively used as an energy source or an industrial raw material.

  From the viewpoint of highly efficient use of biomass, which is renewable energy, biomass is used as a fuel. One of the methods used as fuel is a method in which biomass solids are pulverized and pulverized and supplied to a coal-fired boiler for use as fuel. When biomass is used as a fossil fuel, there is a single pulverization method in which coal and biomass are pulverized independently. In this case, a combustion burner for coal and a combustion burner for biomass are provided, and a flame is formed by separately blowing coal and biomass, which are atomized by each burner, into the furnace together with air.

  Examples of conventional boilers that supply and burn such pulverized coal and biomass in a furnace include those described in Patent Documents 1 and 2 below.

JP 2013-133944 A Japanese Patent No. 389958

  By the way, since biomass has higher elasticity than coal, it is difficult to pulverize to a particle size similar to that of pulverized coal by a pulverizer such as a roller mill. For this reason, when biomass with a large particle size is supplied to the furnace by a combustion burner, it tends to fall before combustion and become unburned, and the unburned rate of fuel increases and boiler efficiency decreases. There is a problem that it ends up.

  The present invention solves the above-described problems, and an object thereof is to provide a boiler that reduces unburned fuel and improves boiler efficiency.

  In order to achieve the above object, a boiler according to the present invention has a furnace having a hollow shape and installed in a vertical direction, and a first fuel gas in which pulverized coal and combustion air are mixed is directed into the furnace. A first combustion burner capable of forming a first flame swirl by blowing, and a second fuel gas in which pulverized biomass and combustion air are mixed are blown into the furnace to have a smaller diameter than the first flame swirl And a second combustion burner capable of forming the second flame swirl flow.

  Therefore, the first combustion burner forms the first flame swirl flow by blowing the first fuel gas into the furnace, and the second combustion burner blows the second fuel gas into the furnace. Two flame swirl is formed. At this time, since the first flame swirl flow and the second flame swirl flow are formed inside the furnace, an upward flow is formed at the center of the flame swirl flow. Therefore, although the pulverized biomass has a specific gravity smaller than that of coal, the second flame swirl is supplied to the center of the furnace because the second flame swirl has a smaller diameter than the first flame swirl and rises in the furnace by this upflow. It will burn properly without falling. As a result, boiler efficiency can be improved by reducing unburned fuel in the furnace.

  In the boiler according to the present invention, the first combustion burner is arranged in a plurality of stages in the vertical direction of the furnace, and the second combustion burner is arranged between the first combustion burners in a plurality of stages. Yes.

  Accordingly, the second fuel gas mixed with the pulverized biomass and the combustion air is supplied and combusted during the first flame swirling flow in which the first fuel gas mixed with the pulverized coal and the combustion air is combusted. By combusting the activated biomass effectively, the unburned content can be reduced.

  The boiler according to the present invention is characterized in that a fuel gas injection direction adjusting device capable of adjusting the injection direction of the second fuel gas by the second combustion burner in a horizontal direction is provided.

  Therefore, by allowing the fuel gas injection direction adjusting device to adjust the injection direction of the second fuel gas, which is a mixture of pulverized biomass and combustion air, to the horizontal direction, the pulverized biomass is appropriately raised and properly burned. be able to.

  In the boiler of this invention, the measurement result of the 1st pulverized biomass unburned amount measuring device which measures the unburned amount of the said pulverized biomass which fell to the bottom part of the said furnace, and the said 1st pulverized biomass unburned amount measuring device And a control device for operating the fuel gas injection direction adjusting device.

  Therefore, since the injection direction of the second fuel gas is adjusted according to the amount of unburned biomass that has fallen to the bottom of the furnace, the pulverized biomass can be appropriately raised and burned efficiently.

  In the boiler according to the present invention, the control device adjusts the second flame swirl flow to have a small diameter by the fuel gas injection direction adjusting device when the unburned amount of the pulverized biomass increases. .

  Therefore, when the amount of unburned biomass of the pulverized biomass increases, the second flame swirl flow is adjusted so as to have a small diameter, so that the pulverized biomass can be appropriately raised and combusted properly.

  In the boiler of the present invention, a second pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass at the outlet portion of the furnace is provided, and the control device falls on the bottom of the furnace. The fuel gas injection direction adjusting device is operated so that the total amount of the unburned amount of the pulverized biomass and the unburned amount of the pulverized biomass at the outlet portion of the furnace is decreased.

  Therefore, in order to adjust the injection direction of the second fuel gas so that the total amount of the unburned amount of the pulverized biomass falling to the bottom of the furnace and the unburned amount of the pulverized biomass at the outlet of the furnace is reduced, The total amount of fuel can be reduced appropriately.

  In the boiler of the present invention, the pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass that has fallen to the bottom of the furnace, and the second combustion when the unburned amount of the pulverized biomass is increased. And a control device for reducing the injection amount of the pulverized biomass injected from the burner.

  Therefore, the amount of unburned fuel can be appropriately reduced by reducing the amount of pulverized biomass injected when the amount of unburned biomass increases.

  In the boiler of the present invention, the pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass that has fallen to the bottom of the furnace, and the second combustion when the unburned amount of the pulverized biomass is increased. A control device for reducing the particle size of the pulverized biomass injected from the burner is provided.

  Therefore, the amount of unburned fuel can be appropriately reduced by reducing the particle size of the pulverized biomass when the amount of unburned biomass is increased.

  According to the boiler of the present invention, the first combustion burner capable of forming the first flame swirl flow by blowing the first fuel gas mixed with the pulverized coal and the combustion air into the furnace, the pulverized biomass and the combustion A second combustion gas burner that can form a second flame swirl flow smaller in diameter than the first flame swirl flow by blowing the second fuel gas mixed with working air into the furnace is supplied to the center of the furnace The pulverized biomass thus produced can be dropped and combusted appropriately by raising the inside of the furnace by the upward flow, and the unburned portion of the fuel in the furnace can be reduced and the boiler efficiency can be improved.

Drawing 1 is a schematic structure figure showing the boiler of a 1st embodiment. FIG. 2 is a plan view of a first combustion burner for pulverized coal. FIG. 3 is a plan view of a second combustion burner for pulverized biomass. FIG. 4 is a schematic configuration diagram illustrating a boiler according to the second embodiment. FIG. 5 is a plan view of a second combustion burner for pulverized biomass. FIG. 6 is a schematic configuration diagram illustrating a boiler according to the third embodiment. FIG. 7 is a schematic configuration diagram illustrating a boiler according to the fourth embodiment. FIG. 8 is a schematic configuration diagram illustrating a boiler according to the fifth embodiment.

  Hereinafter, preferred embodiments of a boiler according to the present invention will be described 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. 1 is a schematic configuration diagram illustrating a boiler according to the first embodiment, FIG. 2 is a plan view of a first combustion burner for pulverized coal, and FIG. 3 is a plan view of a second combustion burner for pulverized biomass. .

  The boiler according to the first embodiment uses pulverized coal obtained by pulverizing coal and pulverized biomass obtained by pulverizing biomass as fuels, and each of the pulverized coal and pulverized biomass is burned by a combustion burner, and heat generated by the combustion is recovered. It is a boiler that can do.

  In the first embodiment, as shown in FIG. 1, the boiler 10 is a conventional boiler and includes a furnace 11 and a combustion device 12. 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 apparatus 12 is provided in the lower part of the furnace wall which comprises this furnace 11. FIG. This combustion apparatus 12 has a plurality of combustion burners 21, 22, 23, 24, 25 mounted on the furnace wall. In this embodiment, the combustion burners 21, 22, 23, 24, and 25 are arranged as four sets at equal intervals along the circumferential direction, and five sets along the vertical direction. Five stages are arranged. The shape of the furnace, the number of combustion burners in one stage, and the number of stages are not limited to this embodiment.

  The first combustion burners 21, 22, 24, 25 are connected to pulverized coal machines (mills) 31, 32, 34, 35 via pulverized coal supply pipes 26, 27, 29, 30. Although not shown, the pulverized coal machines 31, 32, 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. The crushing roller is configured to be rotatably supported in conjunction with the rotation of the crushing 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, 29, 30 can be supplied to the first combustion burners 21, 22, 24, 25.

  The second combustion burner 23 is connected to a pulverized biomass machine (mill) 33 via a pulverized biomass supply pipe 28. Although not shown, the pulverizing biomass machine 33 is 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 pulverization rollers are opposed to the upper side of the pulverization table. It is configured to be supported so as to be rotatable in conjunction with the rotation. Therefore, when biomass is introduced between a plurality of pulverizing rollers and a pulverizing table, the pulverized biomass that has been pulverized to a predetermined size and classified by the conveying air (primary air) is then pulverized biomass supply pipe. 28 to the second combustion burner 23.

  In the furnace 11, a wind box 36 is provided at the mounting position of each combustion burner 21, 22, 23, 24, 25, and one end of an air duct 37 is connected to the wind box 36. The duct 37 has a blower 38 attached to 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 the 1st combustion burners 21, 22, 24, and 25 which comprise this combustion apparatus 12 have comprised the substantially same structure, the 1st combustion burner 12 located in the uppermost stage is comprised. Only the one combustion burner 21 will be described.

  The 1st combustion burner 21 is comprised from the combustion burners 21a, 21b, 21c, and 21d provided in the four wall parts in the furnace 11, as shown in FIG. 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. In this case, the combustion burners 21a, 21b, 21c, and 21d can inject the first pulverized fuel mixture at an angle of 90 degrees with respect to each wall portion of the furnace 11.

  Therefore, each combustion burner 21a, 21b, 21c, 21d in each wall portion of the furnace 11 blows into the furnace 11 a pulverized fuel mixture (first fuel) in which pulverized coal and carrier air are mixed, Combustion air is blown outside the first pulverized fuel mixture. Then, by igniting the first pulverized fuel mixture from each combustion burner 21a, 21b, 21c, 21d, four flames F1, F2, F3, F4 can be formed, and these flames F1, F2, F3 , F4 becomes a first flame swirl flow swirling counterclockwise as viewed from above the furnace 11 (in FIG. 2). This first flame swirl flow is along a predetermined first virtual circle C1.

  As shown in FIG. 3, the second combustion burner 23 is composed of combustion burners 23 a, 23 b, 23 c, and 23 d provided on four walls in the furnace 11. Each combustion burner 23a, 23b, 23c, 23d is connected to each branch pipe 28a, 28b, 28c, 28d branched from the pulverized biomass supply pipe 28, and each branch pipe 37a, 37b branched from the air duct 37. 37c and 37d are connected. In this case, the combustion burners 23a, 23b, 23c, and 23d can inject the second pulverized fuel mixture at an angle of 70 degrees with respect to each wall portion of the furnace 11. That is, the injection angle of the first combustion burner 21 and the injection angle of the second combustion burner 23 are different by 20 degrees.

  Therefore, each combustion burner 23a, 23b, 23c, 23d in each corner of the furnace 11 supplies the second pulverized fuel mixture (second fuel) in which the pulverized biomass and the carrier air are mixed to the furnace 11. While blowing, combustion air is blown outside the second pulverized fuel mixture. Then, by igniting the second pulverized fuel mixture from each combustion burner 23a, 23b, 23c, 23d, four flames F11, F12, F13, F14 can be formed, and this flame F11, F12, F13. , F14 becomes a second flame swirl flow swirling counterclockwise as viewed from above the furnace 11 (in FIG. 3). The second flame swirl flow is along the second virtual circle C2 having a smaller diameter than the first virtual circle C1.

  In addition, each combustion burner 21, 22, 23, 24, 25 which constitutes the combustion apparatus 12 of the present embodiment includes an oil nozzle capable of injecting oil fuel at the center, and a fuel nozzle capable of injecting a pulverized fuel mixture. And a secondary air nozzle capable of injecting secondary air to the outside of the fuel nozzle. Therefore, when the boiler is started, each combustion burner 21, 22, 23, 24, 25 injects oil fuel into the furnace 11 to form a flame, and then the fine fuel mixture and secondary air are introduced into the furnace 11. A flame is formed by spraying.

  Further, the furnace 11 is provided with an additional air injection device 41 above the mounting positions of the combustion burners 21, 22, 23, 24, 25, and the branched air branched from the air duct 37 to the additional air injection device 41. The ends of the duct 42 are connected. Therefore, the combustion air (secondary air) sent by the blower 38 can be supplied from the branch air duct 42 to the additional air injection device 41.

  As shown in FIG. 1, a furnace 11 has a flue 50 connected to an upper portion thereof, and superheaters (superheaters) 51, 52, 53 for recovering heat of exhaust gas in the flue 50, a reheater. 54 and 55 and economizers 56 and 57 are provided, and heat exchange is performed between the exhaust gas generated by the combustion in the furnace 11 and water.

  The flue 50 is connected to an exhaust gas duct 58 to which exhaust gas subjected to heat exchange is discharged downstream. This exhaust gas duct 58 is provided with an air heater 59 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 exhaust gas duct 58, and the combustion burners 21, 22, 23, The temperature of the combustion air supplied to 24 and 25 can be raised.

  Although not shown, the exhaust gas duct 58 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.

  When the pulverized coal machines 31, 32, 34, and 35 are driven in the coal-fired boiler 10 configured as described above, the supplied coal is pulverized, and the generated pulverized coal is pulverized coal supply pipe 26 by the air for conveyance. , 27, 29, 30 are supplied to the first combustion burners 21, 22, 24, 25. Further, when the pulverized biomass machine 33 is driven, the biomass is pulverized, and the generated pulverized biomass is supplied to the second combustion burner 23 through the pulverized biomass supply pipe 28 by the carrier air. Further, the heated combustion air is supplied from the air duct 37 to the combustion burners 21, 22, 23, 24, 25 through the wind box 36.

  Then, the first combustion burners 21, 22, 24, and 25 blow the first pulverized fuel mixture, which is a mixture of pulverized coal and carrier air, into the combustion region A of the furnace 11 and the combustion air into the combustion region of the furnace 11. A first flame swirl is formed in the combustion region A by blowing into A and igniting at this time. On the other hand, the second combustion burner 23 blows the second pulverized fuel mixture, in which the pulverized biomass and the carrier air are mixed, into the furnace 11 and blows the combustion air into the combustion region A of the furnace 11 and ignites at this time. Thus, a second flame swirl flow is formed in the combustion region A. Further, the additional air injection device 41 blows additional air above the first flame swirl flow and the reduction region B in the furnace 11 to perform combustion control. In the furnace 11, the first and second pulverized fuel mixtures and the combustion air are combusted to generate first and second flame swirl flows. When the flame swirl flow is generated in the combustion region A, the furnace 11 is combusted. The gas (exhaust gas) rises while turning and reaches the reduction region B.

  At this time, in the second flame swirl formed by the second combustion mixture being injected from the second combustion burner 23, the first combustion mixture is injected from the first combustion burners 21, 22, 24, 25. Is sandwiched between the upper and lower sides of the first flame swirl formed and positioned on the inner side (center side) of the furnace 11. Further, since the first flame swirl flow and the second flame swirl flow are formed in the furnace 11, an upward flow is formed at the center of the flame swirl flow. Therefore, the pulverized biomass rises in the furnace 11 by the upward flow formed in the central portion of the furnace 11, and is combusted properly without falling.

  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 and pulverized biomass. The reduction region B above the combustion region A is maintained in a reducing atmosphere. Therefore, NOx generated by the combustion of the pulverized fuel mixture is reduced in the reduction region B. The additional air injection device 41 blows additional air above the reduction region B in the furnace 11. Then, the exhaust gas and the additional air react above the reduction region B, whereby the combustion of the pulverized fuel is completed and the unburned portion is combusted.

  The water supplied from a water supply pump (not shown) is preheated by the economizers 56 and 57, 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 51, 52, and 53 and is heated by the combustion gas. The superheated steam generated by the superheaters 51, 52, 53 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 54 and 55, 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 56 and 57 of the flue 50 is subjected to removal of harmful substances such as NOx by a catalyst in a denitration device (not shown) in an exhaust gas duct 58, and particulate matter is removed by an electric dust collector. Then, after the sulfur content is removed by the desulfurization device, it is discharged into the atmosphere from the chimney.

  As described above, in the boiler according to the first embodiment, the furnace 11 that has a hollow shape and is installed along the vertical direction, and the first pulverized fuel mixture obtained by mixing pulverized coal and combustion air are contained in the furnace 11. The first combustion burners 21, 22, 24, and 25 that can form a first flame swirl flow by blowing into the furnace and the second pulverized fuel mixture obtained by mixing pulverized biomass and combustion air are directed into the furnace 11. And a second combustion burner 23 capable of forming a second flame swirl flow having a smaller diameter than the first flame swirl flow.

  Accordingly, the first combustion burners 21, 22, 24, 25 form the first flame swirl flow by blowing the first pulverized fuel mixture into the furnace 11, and the second combustion burner 23 is the second pulverized powder. A second flame swirl is formed by blowing the fuel mixture into the furnace 11. At this time, since the first flame swirl flow and the second flame swirl flow are formed inside the furnace 11, an upward flow is formed at the center of the flame swirl flow. Therefore, although pulverized biomass has a specific gravity smaller than that of coal, the second flame swirl is smaller in diameter than the first flame swirl, so that it is supplied to the center of the furnace 11 and rises in the furnace by this upflow. Will burn properly without falling. As a result, the unburned biomass in the furnace 11 can be reduced and the boiler efficiency can be improved.

  In the boiler according to the first embodiment, the first combustion burners 21, 22, 24, 25 are arranged in a plurality of stages in the vertical direction of the furnace 11, and the second combustion burner 23 is a plurality of stages of the first combustion burners 21, 22, 24. , 25. Accordingly, the second fuel gas mixed with the pulverized biomass and the combustion air is supplied and combusted during the first flame swirling flow in which the first fuel gas mixed with the pulverized coal and the combustion air is combusted. By combusting the activated biomass effectively, the unburned content can be reduced.

[Second Embodiment]
FIG. 4 is a schematic configuration diagram showing the boiler of the second embodiment, and FIG. 5 is a plan view of a second combustion burner for pulverized biomass. 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 FIG. 4, the boiler 10 includes a furnace 11 and a combustion device 12. The combustion device 12 has a plurality of combustion burners 21, 22, 23, 24, 25 mounted on the furnace wall. The first combustion burners 21, 22, 24, 25 are connected to the pulverized coal machines 31, 32, 34, 35 via pulverized coal supply pipes 26, 27, 29, 30. The second combustion burner 23 is connected to the pulverized biomass machine 33 via the pulverized biomass supply pipe 28. In the furnace 11, a wind box 36 is provided at the mounting position of each combustion burner 21, 22, 23, 24, 25, and one end of an air duct 37 is connected to the wind box 36. The duct 37 has a blower 38 attached to the other end.

  Here, although the combustion apparatus 12 is demonstrated in detail, since the 1st combustion burners 21, 22, 24, and 25 which comprise this combustion apparatus 12 are the same as that of 1st Embodiment mentioned above, description is abbreviate | omitted.

  As shown in FIGS. 4 and 5, the second combustion burner 23 is composed of combustion burners 23 a, 23 b, 23 c, and 23 d provided on four wall portions in the furnace 11. Each combustion burner 23a, 23b, 23c, 23d is connected to each branch pipe 28a, 28b, 28c, 28d branched from the pulverized biomass supply pipe 28, and each branch pipe 37a, 37b branched from the air duct 37. 37c and 37d are connected. Further, each combustion burner 23a, 23b, 23c, 23d has an injection direction adjusting device (fuel gas injection direction adjusting device) 61 (61a, 61b, 61c, 61) capable of adjusting the injection direction of the second pulverized fuel mixture in the horizontal direction. 61d) is provided. This injection direction adjusting device 61 (61a, 61b, 61c, 61d), for example, turns the nozzle part of the combustion burners 23a, 23b, 23c, 23d left and right by an adjusting motor (not shown) and mixes the second pulverized fuel. Qi injection angle can be adjusted. Actually, it is desirable to adjust the injection angles of the combustion burners 23a, 23b, 23c, and 23d to be smaller than the injection angles of the first combustion burners 21a, 21b, 21c, and 21d. That is, by igniting the second pulverized fuel mixture from each combustion burner 23a, 23b, 23c, 23d of the second combustion burner 23, four flames F11, F12, F13, F14 along the second virtual circle C2 are ignited. Form.

Moreover, as shown in FIG. 4, the furnace 11 is provided with the hopper 62 in the lower end part, and can store the ash and unburned content of pulverized coal or pulverized biomass. The furnace 11 is provided with a first pulverized biomass unburned amount measuring device 63 that measures the unburned amount of pulverized biomass that has fallen to the bottom of the hopper 62. The first pulverized biomass unburned amount measuring device 63 may be a microwave device, a combustion-CO ₂ detector, a laser induction device, or the like. The first pulverized biomass unburned amount measuring device 63 is connected to the first unburned amount analyzing device 64, and the first unburned biomass analyzing device 64 uses the detection result of the first pulverized biomass unburned amount measuring device 63. Based on this, the trend of increase / decrease in the amount of unburned biomass is analyzed.

  The control device 65 is connected to the injection direction adjusting device 61 and the first unburned component analyzer 64. The control device 65 can control (feedback control) the operation of the injection direction adjusting device 61 according to the analysis result of the first unburned component analyzer 64. Specifically, when the amount of unburned biomass of the pulverized biomass increases, the control device 65 adjusts the second flame swirl flow to have a small diameter by the injection direction adjusting device 61.

  Accordingly, the first combustion burners 21, 22, 24, and 25 blow the first pulverized fuel mixture and the combustion air mixed with the pulverized coal and the carrier air into the combustion region A of the furnace 11, and ignite at this time. Thus, a first flame swirl flow is formed in the combustion region A. On the other hand, the second combustion burner 23 blows into the combustion area A of the furnace 11 the second pulverized fuel mixture and the combustion air in which the pulverized biomass and the carrier air are mixed, and ignites at this time so that this combustion area A second flame swirl is formed in A. Further, the additional air injection device 41 blows additional air above the first flame swirl flow and the reduction region B in the furnace 11 to perform combustion control. In the furnace 11, the first and second pulverized fuel mixtures and the combustion air are combusted to generate first and second flame swirl flows. When the flame swirl flow is generated in the combustion region A, the furnace 11 is combusted. The gas (exhaust gas) rises while turning and reaches the reduction region B.

  At this time, in the second flame swirl formed by the second combustion mixture being injected from the second combustion burner 23, the first combustion mixture is injected from the first combustion burners 21, 22, 24, 25. Is sandwiched between the upper and lower sides of the first flame swirl formed and positioned on the inner side (center side) of the furnace 11. Further, since the first flame swirl flow and the second flame swirl flow are formed in the furnace 11, an upward flow is formed at the center of the flame swirl flow. Therefore, the pulverized biomass rises in the furnace 11 by the upward flow formed in the central portion of the furnace 11, and is combusted properly without falling.

  Further, the first pulverized biomass unburned amount measuring device 63 measures the unburned amount of the pulverized biomass dropped on the hopper 62 of the furnace 11 and outputs it to the first unburned amount analyzing device 64. The first unburned amount analysis device 64 analyzes the increase / decrease tendency of the unburned biomass amount of the pulverized biomass based on the detection result of the first pulverized biomass unburned amount measurement device 63 and outputs it to the control device 65. Then, the control device 65 controls the operation of the injection direction adjusting device 61 according to the analysis result of the first unburned component analyzer 64. That is, when the amount of unburned biomass of the pulverized biomass increases, the control device 65 adjusts the second flame swirl flow to have a small diameter by reducing the angle of the second combustion burner 23.

  As described above, in the boiler according to the second embodiment, the injection direction adjusting device 61 capable of adjusting the injection direction of the second pulverized fuel mixture by the second combustion burner 23 in the horizontal direction is provided.

  Therefore, by enabling the injection direction of the second pulverized fuel mixture obtained by mixing the pulverized biomass and the combustion air by the injection direction adjusting device 61 to be adjusted in the horizontal direction, the pulverized biomass is appropriately raised and burned efficiently. Can be made.

  In the boiler of the second embodiment, a first pulverized biomass unburned amount measuring device 63 that measures the amount of unburned biomass that has fallen to the bottom of the furnace 11, and a first pulverized biomass unburned amount measuring device 63. A control device 65 that operates the fuel gas injection direction adjusting device 61 according to the measurement result is provided. Therefore, by adjusting the injection angle of the second combustion burner so that the amount of unburned biomass of the pulverized biomass is minimized, the pulverized biomass can be appropriately raised and combusted.

  In the boiler of the second embodiment, the control device 65 adjusts the second flame swirl flow to have a small diameter by the injection direction adjusting device 61 when the unburned amount of the pulverized biomass increases. Therefore, if the unburned amount of pulverized biomass increases, the pulverized biomass can be appropriately raised and burned by adjusting the injection angle of the second combustion burner to be small.

[Third Embodiment]
FIG. 6 is a schematic configuration diagram illustrating a boiler 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. 6, the boiler 10 includes a furnace 11 and a combustion device 12. The combustion device 12 has a plurality of combustion burners 21, 22, 23, 24, 25 mounted on the furnace wall. The first combustion burners 21, 22, 24, and 25 can inject pulverized coal into the furnace 11, and the second combustion burner 23 can inject pulverized biomass into the furnace 11. The second combustion burner 23 is provided with an injection direction adjusting device 61 capable of adjusting the injection direction of the second pulverized fuel mixture in the horizontal direction.

The furnace 11 is provided with a first pulverized biomass unburned amount measuring device 63 that measures the unburned amount of the pulverized biomass dropped on the hopper 62. The first pulverized biomass unburned amount measuring device 63 is connected to the first unburned amount analyzing device 64, and the first unburned biomass analyzing device 64 uses the detection result of the first pulverized biomass unburned amount measuring device 63. Based on this, the trend of increase / decrease in the amount of unburned biomass is analyzed. Further, the furnace 11 is provided with a second pulverized biomass unburned amount measuring device 71 that measures the unburned amount of pulverized biomass in the exhaust gas discharged from the flue 50. The second unburned biomass unburned amount measuring device 71 is connected to the second unburned biomass analyzing device 72, and the second unburned biomass analyzing device 72 is connected to the detection result of the second pulverized biomass unburned amount measuring device 71. Based on this, the trend of increase / decrease in the amount of unburned biomass is analyzed. Note that the first and second pulverized biomass unburned amount measuring devices 63 and 71 may use a microwave device, a combustion-CO ₂ detector, a laser induction device, or the like.

  The control device 65 is connected to the injection direction adjusting device 61, the first unburned component analyzer 64, and the second unburned component analyzer 72. The control device 65 can control the operation of the injection direction adjusting device 61 according to the analysis results of the first unburned component analyzer 64 and the second unburned component analyzer 72. The control device 65 controls the injection direction adjusting device 61 so that the total amount of the unburned amount of the pulverized biomass falling to the bottom of the furnace 11 and the unburned amount of the pulverized biomass at the outlet of the flue 50 in the furnace 11 is reduced. Operate control (feedback control).

  Accordingly, the first combustion burners 21, 22, 24, and 25 blow the first pulverized fuel mixture and the combustion air mixed with the pulverized coal and the carrier air into the combustion region A of the furnace 11, and ignite at this time. Thus, a first flame swirl flow is formed in the combustion region A. On the other hand, the second combustion burner 23 blows into the combustion area A of the furnace 11 the second pulverized fuel mixture and the combustion air in which the pulverized biomass and the carrier air are mixed, and ignites at this time so that this combustion area A second flame swirl is formed in A. Further, the additional air injection device 41 blows additional air above the first flame swirl flow and the reduction region B in the furnace 11 to perform combustion control. In the furnace 11, the first and second pulverized fuel mixtures and the combustion air are combusted to generate first and second flame swirl flows. When the flame swirl flow is generated in the combustion region A, the furnace 11 is combusted. The gas (exhaust gas) rises while turning and reaches the reduction region B.

  At this time, in the second flame swirl formed by the second combustion mixture being injected from the second combustion burner 23, the first combustion mixture is injected from the first combustion burners 21, 22, 24, 25. Is sandwiched between the upper and lower sides of the first flame swirl formed and positioned on the inner side (center side) of the furnace 11. Further, since the first flame swirl flow and the second flame swirl flow are formed in the furnace 11, an upward flow is formed at the center of the flame swirl flow. Therefore, the pulverized biomass rises in the furnace 11 by the upward flow formed in the central portion of the furnace 11, and is combusted properly without falling.

  Further, the first pulverized biomass unburned amount measuring device 63 measures the unburned amount of the pulverized biomass dropped on the hopper 62 of the furnace 11 and outputs it to the first unburned amount analyzing device 64. The second pulverized biomass unburned amount measuring device 71 measures the unburned amount of pulverized biomass in the exhaust gas discharged from the outlet of the furnace 11 and outputs the measured amount to the second unburned amount detecting device 72. The first and second unburned amount analyzers 64 and 72 analyze and control the increase / decrease tendency of the unburned amount of the pulverized biomass based on the detection results of the first and second biomass unburned amount measuring devices 63 and 71. Output to the device 65. Then, the control apparatus 65 injects so that the total amount of the unburned part of the pulverized biomass which fell to the bottom part of the furnace 11 and the unburned part of the pulverized biomass in the exhaust gas discharged | emitted from the flue 50 in the furnace 11 may decrease. The direction adjusting device 61 is operated.

  In addition, as the furnace 11, the unburned amount of the pulverized biomass dropped on the bottom of the furnace 11 is compared with the unburned amount of the pulverized biomass in the exhaust gas discharged from the flue 50 in the furnace 11, and either one of them is compared. The control device 65 may control the injection direction adjusting device 61 so that the amount of unburned biomass of the pulverized biomass decreases. That is, the amount of unburned biomass that has fallen to the bottom of the furnace 11 and the amount of unburned biomass in the exhaust gas discharged from the flue 50 in the furnace 11 are increased or decreased. 65 should just operate-control the injection direction adjustment apparatus 61 so that both quantity may become appropriate.

  As described above, in the boiler according to the third embodiment, the second pulverized biomass unburned amount measuring device 71 that measures the unburned amount of pulverized biomass at the outlet of the furnace 11 is provided, and the control device 65 is connected to the furnace. The injection direction adjusting device 61 is operated so that the unburned amount of pulverized biomass that has fallen to the bottom of 11 and the total amount of unburned amount of pulverized biomass at the outlet of the furnace are reduced.

  Therefore, the amount of unburned biomass generated in the furnace 11 can be reduced.

[Fourth Embodiment]
FIG. 7 is a schematic configuration diagram illustrating a boiler 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. 7, the furnace 11 is provided with a first pulverized biomass unburned amount measuring device 63 that measures the unburned amount of pulverized biomass dropped on the bottom of the hopper 62. . The first pulverized biomass unburned amount measuring device 63 is connected to the first unburned amount analyzing device 64, and the first unburned biomass analyzing device 64 uses the detection result of the first pulverized biomass unburned amount measuring device 63. Based on this, the trend of increase / decrease in the amount of unburned biomass is analyzed.

  The pulverized biomass machine 33 is provided with a biomass supply machine 81 for supplying biomass. The control device 65 is connected to the biomass feeder 81 and the first unburned component analyzer 64. The control device 65 can control the operation of the biomass feeder 81 according to the analysis result of the first unburned component analyzer 64. Specifically, when the amount of unburned biomass of the pulverized biomass increases, the control device 65 decreases the amount of biomass supplied to the pulverized biomass machine 33 by the biomass feeder 81 and pulverizes the fuel from the second combustion burner 23. Reduce the amount of biomass injection.

  Thus, in the boiler according to the fourth embodiment, the first pulverized biomass unburned amount measuring device 63 for measuring the unburned amount of the pulverized biomass falling on the bottom of the furnace 11, and the unburned of the pulverized biomass. A control device 65 is provided for reducing the amount of pulverized biomass injected from the second combustion burner 23 when the amount increases.

  Therefore, the amount of unburned biomass of pulverized biomass can be reduced.

[Fifth Embodiment]
FIG. 8 is a schematic configuration diagram illustrating a boiler according to the fifth 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 fifth embodiment, as shown in FIG. 8, the furnace 11 is provided with a first pulverized biomass unburned amount measuring device 63 that measures the unburned amount of pulverized biomass dropped on the bottom of the hopper 62. . The first pulverized biomass unburned amount measuring device 63 is connected to the first unburned amount analyzing device 64, and the first unburned biomass analyzing device 64 uses the detection result of the first pulverized biomass unburned amount measuring device 63. Based on this, the trend of increase / decrease in the amount of unburned biomass is analyzed.

  The pulverized biomass machine 33 is provided with a pulverized biomass classifier (separator) 82 for classifying the pulverized biomass. The control device 65 is connected to the pulverized biomass classifier and the first unburned component analyzer 64. The control device 65 can control the operation of the pulverized biomass classifier 82 according to the analysis result of the first unburned component analyzer 64. Specifically, when the unburned amount of the pulverized biomass increases, the control device 65 reduces the particle size of the pulverized biomass classified by the pulverized biomass classifier 82 and pulverizes the fuel from the second combustion burner 23. Reduce the particle size of the biomass.

  As described above, in the boiler according to the fifth embodiment, the first pulverized biomass unburned amount measuring device 63 that measures the unburned amount of the pulverized biomass dropped on the bottom of the furnace 11, and the unburned of the pulverized biomass. A controller 65 is provided for reducing the particle size of the pulverized biomass injected from the second combustion burner 23 when the amount is increased.

  Therefore, the amount of unburned biomass of pulverized biomass can be reduced.

  In the above-described embodiment, the combustion burners 21, 22, 23, 24, and 25 are the CUF (Circular Ultra Filing) combustion method. However, the present invention is not limited to this method, and the CCF (Circular Corner Firing) combustion method is used. It is good.

DESCRIPTION OF SYMBOLS 10 Boiler 11 Furnace 12 Combustion device 21, 22, 24, 25 First combustion burner 23 Second combustion burner 26, 27, 29, 30 Pulverized coal supply pipe 28 Pulverized biomass supply pipe 31, 32, 34, 35 Pulverized coal machine 33 pulverized biomass machine 36 wind box 37 air duct 41 additional air injection device 61 injection direction adjusting device 63 first pulverized biomass unburned amount measuring device 64 first unburned biomass analyzing device 65 control device 71 second pulverized biomass not Fuel amount measuring device 72 Second unburned fuel analysis device 81 Biomass supply device 82 Micronized biomass classifier

Claims (8)

A furnace that is hollow and installed along the vertical direction;
A first combustion burner capable of forming a first flame swirl flow by blowing a first fuel gas mixed with pulverized coal and combustion air into the furnace;
A second combustion burner capable of forming a second flame swirl flow having a smaller diameter than the first flame swirl flow by blowing a second fuel gas mixed with pulverized biomass and combustion air into the furnace;
The boiler characterized by having.   The first combustion burner is arranged in a plurality of stages in the vertical direction of the furnace, and the second combustion burner is arranged between the first combustion burners in a plurality of stages. Boiler.   The boiler according to claim 1 or 2, wherein a fuel gas injection direction adjusting device capable of adjusting a horizontal injection direction of the second fuel gas by the second combustion burner is provided.   The fuel gas according to the measurement result of the first pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass falling to the bottom of the furnace and the first pulverized biomass unburned amount measuring device. The boiler according to claim 3, further comprising a control device that operates the injection direction adjusting device.   The said control apparatus is adjusted so that the said 2nd flame swirl flow may become a small diameter with the said fuel gas injection direction adjustment apparatus, if the amount of unburned biomass of the said pulverized biomass increases. boiler.   A second pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass at the outlet of the furnace is provided, and the control device unburns the pulverized biomass that has fallen to the bottom of the furnace. The boiler according to claim 4 or 5, wherein the fuel gas injection direction adjusting device is operated so that the total amount of the unburned portion of the pulverized biomass at the outlet portion of the furnace is reduced.   The pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass falling on the bottom of the furnace, and the fine powder injected from the second combustion burner when the unburned amount of the pulverized biomass is increased. The boiler of Claim 1 or Claim 2 provided with the control apparatus which reduces the injection quantity of activated biomass.   The pulverized biomass unburned amount measuring device for measuring the unburned amount of the pulverized biomass falling on the bottom of the furnace, and the fine powder injected from the second combustion burner when the unburned amount of the pulverized biomass is increased. The boiler according to claim 1 or 2, wherein a control device for reducing the particle size of the activated biomass is provided.

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