KR20140003558A - Solid fuel burner and combustion device using same - Google Patents

Abstract

The outer periphery of the fuel nozzle 10 has a throat 6 for ejecting combustion gas into the furnace 40 and an inlet 8 through which gas is introduced from one direction orthogonal to the central axis direction of the nozzle 10. And the upstream side in the duct 2 and the damper 1 in the duct 2 and the duct 2 which sends the combustion gas to the throat 6, which is bent at right angles in the direction of the center axis of the nozzle 10, A differential pressure detection device 32 is provided which detects the differential pressure of the combustion gas flowing downstream, and a damper 1 is installed downstream of the inlet 8 of the duct 2, and the differential pressure detection device 32 is provided. The upstream pressure detection point 31 at the stagnant region 90 of the combustion gas on the downstream side of the damper 1 and the downstream pressure detection point 30 at the outer wall of the throat 6 for detection. As a solid fuel burner 44 which converts the pressure difference at points 31 and 30 into the flow rate of the gas for combustion, and operates the damper 1 to adjust the flow rate of the gas for combustion, a simple configuration. A, it is possible to provide a localized not affected by drift and to accurately measure the flow rate of the gas for combustion by the burners, the combustion of using the number of the solid fuel burner and the burner to control the device.

Description

Solid fuel burner and combustion apparatus using said burner {SOLID FUEL BURNER AND COMBUSTION DEVICE USING SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner mainly used in a thermal power plant and combusting solid fuel such as pulverized coal and a combustion apparatus using the burner.

In a boiler mainly comprising a plurality of burners for burning solid fuel such as pulverized coal, and employing a two-stage combustion method as a measure for reducing NOx in the combustion exhaust gas of the fuel in the burner, the reduction of excess air ratio and CO, etc. In order to achieve a reduction in unburned emissions, the flow rate of solid fuel is measured separately at each burner, and the corresponding combustion air is recorded at each burner or two stage combustion air inlet (after-air port; AAP The technique (WO2008 / 133051 A1) which throws in from over-fire air port (also called OFA) is known.

In order to apply the above technique to a real boiler, it is required to precisely measure and regulate the flow rate of the gas for combustion for each burner.

On the other hand, even when the capacity of the burner unit is increased in accordance with the large capacity of the boiler, a burner having a flat cross section perpendicular to the flow of the fluid of the fuel nozzle in order to suppress the expansion of the unignited area of the fuel The invention (WO2008 / 038426 A1) is known.

In addition, in order to change the combustion position of the fuel in a furnace and to control the heat transfer to the fluid which flows through a boiler heat exchanger, the combustion oxygen gas which flows through the several divided flow paths surrounding the fuel supply nozzle of a burner. The invention of the burner which can adjust the flow volume of each (Japanese Unexamined-Japanese-Patent No. 2002-147713, WO2009 / 041081 A1) is known.

WO2008 / 133051A1 WO2008 / 038426A1 Japanese Unexamined Patent Publication No. 2002-147713 WO2009 / 041081A1

The flow of combustion gas blown out from the burner is greatly influenced by the structure of the burner, in particular the shape of the flow path of the combustion gas.

In order to precisely measure and regulate the flow rate of the gas for combustion for each burner, it is preferable to form a long linear flow path so that the gas for combustion flows uniformly before and after a measuring means or a control means. However, in the actual boiler, a flow path in which the combustion gas flows uniformly is caused due to installation restrictions in which a plurality of burners must be arranged in a compact manner to avoid interference with a structure other than a furnace. There was a possibility that localization could not be taken and localization would affect the flow rate measurement and regulation.

In particular, in a burner having a flat cross-sectional shape orthogonal to the flow of the fluid of the fuel nozzle described above, drift is likely to occur.

Moreover, in the burner which actively controls the flow volume of the combustion gas which flows through the divided flow path, the number of objects becomes large and adjustment width | variety and a frequency of adjustment also increase, and it becomes a more demanding subject.

The problem of the present invention is that even in a boiler in which the flow path of the combustion gas cannot avoid the occurrence of local drift, a relatively simple configuration makes it less likely to be affected by the local drift and burns each burner individually. It is to provide a solid fuel burner that can accurately measure and regulate the flow rate of the gas.

In addition, the problem of the present invention is a simple configuration, which makes it difficult to be affected by local drift, and precisely measures the flow rate of the combustion gas for each burner, and then adjusts and regulates the amount of air excess and reduces unburned emissions such as CO. It is to provide a solid fuel burner and a combustion device using the burner to achieve a reduction in energy consumption.

It can solve by this invention described below which solves the subject mentioned above.

Invention of Claim 1 has the cylindrical fuel nozzle 10 which ejects the mixed fluid of a solid fuel and its conveyance gas into the furnace 40 from the wall surface of the furnace 40, and the outer periphery of the fuel nozzle 10. A flow path of a combustion gas throat 6 having a tubular combustion gas which is provided in the outside and blows the combustion gas into the furnace 40 and connected to the combustion gas throat 6. Pressure difference (differential pressure) between the duct 2 constituting the air, the flow rate adjusting means 1 of the gas for combustion provided in the duct 2, and the upstream and downstream sides of the duct 2. A solid fuel burner having differential pressure detection devices (32, 35) for detecting), wherein the duct (2) is an inlet for injecting combustion gas from one direction orthogonal to the direction of the center axis of the fuel nozzle (10). 8) so that the flow path of the combustion gas is bent at right angles in the direction of the central axis of the fuel nozzle 10. The flow rate adjusting means 1 of the combustion gas is provided near the inlet 8 of the duct 2, and is provided downstream of the inlet 8, and the differential pressure detection devices 32 and 35 are provided. Is the wake side of the flow rate adjusting means 1, and is located on the inner wall of the duct 2 furthest from the inlet 8 of the duct 2 corresponding to the stagnant region 90 of the combustion gas. Upstream pressure detection points 31 and 33 are provided, and downstream pressure detection points 30 and 34 are provided on the outer wall of the combustion gas throat 6, and the upstream pressure detection devices 32 and 35 are detected. The value of the pressure difference at the side pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34 is converted into the flow rate of the combustion gas, and the flow rate adjusting means 1 is operated to It is a solid fuel burner provided with the control apparatus 37 which adjusts flow volume.

The invention according to claim 2 is characterized in that the flow paths of the combustion gas in the duct 2 connected to the combustion gas throat 6 are divided into a plurality of flow paths in which the gasses for combustion are not introduced into each other by the partition wall 4. The solid fuel burner of Claim 1 which is divided and provided with the said upstream pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34 in each of the said several flow paths.

The invention according to claim 3, wherein the downstream gas pressure detecting points 30, 34 have a maximum combustion gas throat in the radial direction with respect to the central axis of the fuel nozzle 10, wherein the combustion gas throat ( It is a solid fuel burner of Claim 1 formed in 6).

The invention according to claim 4, wherein the differential pressure detection devices (32, 35) are formed through the pressure ducts forming the upstream pressure detection points (31 or 33) and the downstream pressure detection points (30, 34). The solid fuel burner of Claim 1 which is a structure which detects the value of the differential pressure of the upstream pressure and the downstream pressure of the combustion gas in (2).

Invention of Claim 5 is a combustion apparatus which provided the solid fuel burner 44 of Claim 1 in multiple stages in the up-down direction of the wall surface of the furnace 40, and a plurality of rows in the furnace width direction, Comprising: The plurality of said solid fuel burners 44 And a solid fuel flow rate measuring means 71 for individually adjusting and measuring the flow rate of the solid fuel flowing into the tank), and the control device 37 changes the solid fuel flow rate measured by the solid fuel flow rate measuring means 71. In accordance with this, the opening degree of the flow rate adjusting means 1 of the combustion gas is adjusted based on the combustion gas flow rates detected by the differential pressure detection devices 32 and 35 of the solid fuel burners 44, It is a combustion apparatus provided with the structure which individually controls the flow volume of the gas for combustion.

In the present invention, the stagnant region 90 (Figs. 2 and 3) of the combustion gas for setting upstream pressure detection points 31 and 33, which is one of the pressure detection points, has almost a flow rate of the combustion gas. None, or the region with the smallest flow velocity in the flow path.

Specifically, the upstream pressure detection points 31 and 33 correspond to the inner wall of the duct 2 furthest from the inlet 8 of the duct 2 of the combustion gas. For example, the duct 2 shown in FIG. 2 is arrange | positioned at the front wall 56 close to a furnace side, and the space parallel to this, and the rear wall located in the position far from a furnace side ( 57 and the inlet opening surface of the duct 2 serving as the inlet 8 of the gas for combustion, when the cubic flow path is formed by the side walls 55 connecting the ridge portions of the front and rear walls 56 and 57. The part farthest from the opening surface of the side wall 55 corresponds to the upstream pressure detection points 31 and 33.

Here, the front wall 56 and the rear wall 57 each have a U-shape (see FIG. 2) in an oval shape, and the side wall 55 has a straight portion and a curved portion at the ridge line between the front wall 56 and the rear wall 57. If it is the form shown in FIG. 2 which divides the flow path (duct 2) of the combustion gas over the outside, the top part of the curved surface which the side wall 55 makes | forms is the upstream pressure detection points 31 and 33 (FIG. 1). Corresponds to).

Moreover, the part of the curved surface which the said side wall 55 makes | forms is in the straight part of the duct 2 in which the gas for combustion goes straight from the flow path cross-sectional area of the duct 2, ie, the inlet port 8 of the duct 2; It can also be said that the area | region of the duct cross section orthogonal to the direction through which the combustion gas flows is infinitely close to zero.

Further, the fuel nozzle 10 has a square shape having a long diameter portion and a short diameter portion in the shape of a cross section orthogonal to the central axis direction (the flow direction of the fluid directed toward the outlet portion), In the case of an ellipse shape or an ellipse shape (FIG. 1 is an example of an ellipse shape), the plane containing the vertex of a long diameter part and the central axis of the fuel nozzle 10 (it is a partition in the form of FIG. 1 (center partition) 4) ) And the area | region along the line which cross | intersects the side wall 55 of the duct 2 becomes an upstream pressure detection point 31 and 33 (FIG. 1).

On the other hand, the downstream pressure detection points 30 and 34 (FIG. 1) which are other pressure detection points are the gas throat 6 for combustion in the opening 58 (FIG. 2) for burner attachment of the furnace 40. FIG. In the case where) is arranged, the combustion gas duct 2 is at the top of the combustion gas throat 6 farthest from the partition wall (center partition) 4 partitioned vertically. In the example where the cross-sectional shape of the fuel nozzle 10 of FIG. 1 to be described later is elliptical, the diameter and the cross-sectional shape of the cylindrical combustion gas throat 6 arranged in a concentric shape of the fuel nozzle 10 are elliptical. The gas for combustion gas which passes through the difference with a short diameter, ie, the central axis of the fuel nozzle 10, and has the largest cross-sectional area of the flow path of the duct 2 of the combustion gas in the radial direction of the fuel nozzle 10. It is at the site of the lot 6. In other words, the plane including the short diameter portion of the fuel nozzle 10 and the central axis of the fuel nozzle 10 is in the region along the line intersecting with the combustion gas throat 6.

Two pressure detection points (the upstream pressure detection point 31 and the downstream pressure detection point 30 of FIG. 1; the upstream pressure detection point 33 and the downstream pressure detection point 34) are the specific 1s. It is not limited to a point or a line, but is an area having a certain width, but more specifically, also determined by the following geometrical numerical range.

The stagnant region 90 (FIGS. 2 and 3) of the combustion gas duct 2, which is a location where the upstream pressure detection points 31 and 33 are disposed, has almost no flow velocity of the combustion gas or the duct 2. As the region having the lowest flow rate within, it passes through the central axis of the fuel nozzle 10 about the partition wall (center partition) 4 which divides the duct 2 on the downstream side of the duct 2 up and down, It is in the area | region enclosed by the plane in the range of 15 degrees each up and down.

As for the part of the throat 6 of the combustion gas which is the location where the downstream pressure detection points 30 and 34 are arrange | positioned, the difference of the diameter of the said throat 6 and the diameter of the flow path of the fuel nozzle 10 is the largest. Based on the position (vertical line passing through the central axis of the combustion gas throat 6 in FIG. 1), the combustion gas throat in the central axis direction within a range of ± 2 ° (see FIG. 12) in the circumferential direction. It exists in the side (refer FIG. 11) downstream from the half of the throat length of (6).

(Action)

The said invention has the following functions.

The value of the differential pressure of the gas for combustion in the upstream pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34 respectively detected by the differential pressure detection devices 32 and 35 is converted into a predetermined conversion equation. By substitution, it can convert into the flow volume of the gas for fuel, and can measure the flow volume of combustion gas (gas, such as air), in each burner.

The said predetermined conversion formula is as follows.

Q = C√OPP (1)

(Q: flow rate, C: integer, OP: differential pressure, P: density of fuel gas)

The combustion gas duct 2 is an inlet 8 for blowing combustion gas from one direction orthogonal to the direction of the central axis of the combustion gas throat 6 (the flow direction of the fluid directed toward the exit portion on the furnace side). ), The flow path (duct) 2 of the combustion gas is formed to be bent at right angles to the central axis direction of the combustion gas throat 6.

Since the differential pressure detection devices 32 and 35 measure the flow rate of the gas for combustion in the duct 2 and adjust the flow rate, the duct length is obtained while suppressing the influence of the drift generated in the duct 2. (2) is compactly housed in the windbox 41 along the wall of the boiler furnace 40.

The flow rate adjusting means 1 of the combustion gas is provided on the current side of the installation portions of the differential pressure detection devices 32 and 35 of the duct 2 of the combustion gas. As a result, the length of the duct subsequent to the flow rate adjusting means 1 of the duct 2 can be ensured to a certain extent, so that the flow velocity distribution in the cross section of the duct of the combustion gas which is particularly large when the opening degree of the inlet 8 is small and tends to be large. Can be reduced to the flow rate adjusting means (1).

In addition, it is possible to avoid the flow rate adjusting means 1 with mechanical operation such as opening and closing, receiving direct radiant heat from the furnace 40, or colliding with a clinker or the like falling from above the furnace 40 or the like. It is possible to reduce the possibility of damage or malfunction caused by them.

The differential pressure detecting devices 32 and 35 are the downstream side of the flow rate adjusting means 1 and are the duct 2 farthest from the inlet 8 of the duct 2 corresponding to the stagnant region 90 of the combustion gas. Since the inner wall portion of the upper portion is used as the upstream pressure detection points 31 and 33, the influence of the dynamic pressure acting on the pressure detection points 31 and 33 is reduced, and the combustion gas throat 6 Since the downstream pressure detection points 30 and 34 are arranged on the top wall and the bottom wall of the c), the flow rate of the gas for fuel can be measured without being influenced by the drift of the gas for combustion. Measurement can be performed with high precision.

The duct 2 of the combustion gas connected to the combustion gas throat 6 is divided into two by the partition (central partition) 4, and the upstream pressure detection point 31 of each of these divided flow paths, respectively. 33 and downstream pressure detection points 30, 34 are provided.

As a result, the flow rate of the combustion gas flowing through the plurality of ducts 2 is varied above and below the combustion air outlet 7 of the burner 44, and is individually adjusted precisely to adjust the flow rate in the furnace 40. The position at which the flame is formed can be controlled, and the reduction of the nitrogen oxide NOx concentration in the combustion exhaust gas and the control of the heat transfer amount to the heat transfer pipe (not shown) provided in the boiler furnace 40 can be effectively performed. When the duct 2 is divided into a plurality of flow paths, the object of measurement and adjustment of the flow rate of the gas for combustion increases, and the adjustment width and frequency also increase in order to actively change the flow rate for each flow path. The configuration using the points 31 and 33 and the downstream pressure detection points 30 and 34 is of high importance.

In addition, the fuel nozzle 10 has a rectangular shape and an ellipse shape in which the cross section orthogonal to the central axis direction (flow direction of the fluid directed to the furnace side outlet) where the gas for combustion is easily generated, has a long diameter portion and a short diameter portion. Alternatively, the combustion gas throat in which the cross-sectional area of the combustion gas flow in the radial direction with respect to the central axis of the combustion gas throat 6 is maximized even in the elliptical shape. By forming on the outer wall surface of 6), it is not influenced by a drift, and the flow volume of the gas for combustion can be measured precisely.

The differential pressure detecting devices 32 and 35 are provided with the upstream pressure and the downstream pressure of the combustion gas through the pressure conduits constituting the upstream pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34. By detecting the value of the differential pressure, it can be realized without causing a significant increase in the equipment cost.

In particular, a plurality of rows are provided in a plurality of stages and a furnace width direction in the up and down direction of the wall surface of the furnace 40, and a solid fuel flow rate measuring unit 71 for individually measuring the flow rate of the solid fuel flowing into the solid fuel burner 44 is provided. And a plurality of flow paths in a combustion apparatus such as a boiler configured to individually control the gas flow rate for combustion in accordance with the change of the fuel flow rate measured by the solid fuel flow rate measurement means 71. This is important when it is required to individually and precisely control the flow rate of the combustion gas flowing through the reactor, because of the large number of devices required. In addition, it is not limited to the combustion apparatus of this invention, It can use also for the other combustion apparatus using the solid fuel burner 44.

According to the invention of claim 1, the duct 2 of the combustion gas has an inlet 8 for blowing the combustion gas from one direction orthogonal to the central axis direction of the combustion gas throat 6, The duct 2 is formed to be bent at right angles in the direction of the central axis of the combustion gas throat 6, and the flow rate adjusting means 1 of the combustion gas is a current in the duct 2 for the combustion gas. Since it is provided in the part, the length of the said duct 2 can be ensured to some extent, and the flow velocity in the duct cross section of the gas for combustion which arises when the opening degree of the inflow opening 8 is especially small in the flow regulating means 1, and becomes easy to become large. Magnification of the distribution can be reduced.

In addition, since the upstream pressure detection points 31 and 33 are formed in the stagnant region 90 of the fuel gas in the duct 2, the influence of dynamic pressure acting on the upstream pressure detection points 31 and 33 is small. The flow rate measurement of the fuel gas can be performed with high accuracy, and the value of the differential pressure detected by the differential pressure detection devices 32 and 35 can be converted into the flow rate of the fuel gas by substituting the predetermined conversion formula (1). Each burner can measure the flow rate of the gas for combustion (gas, such as air). In this way, the gas flow rate for combustion can be measured without being influenced by the drift of the gas for combustion.

In addition, since the flow rate of combustion gas is measured by the differential pressure detecting devices 32 and 35 and the flow rate is adjusted by the flow rate adjusting means 1, the influence of the drift generated in the duct 2 of the fuel gas is suppressed. The duct 2 is compactly housed in the windbox 41 along the wall of the boiler furnace 40 while obtaining the duct length necessary to make it.

Further, since the flow rate adjusting means 1 is in the duct 2, the flow rate adjusting means 1 with mechanical operation such as opening and closing receives direct radiant heat from the furnace 40 or falls from above the furnace 40 or the like. It is possible to avoid the collision of clinkers and the like, and to reduce the possibility of damage or malfunction caused by them.

According to invention of Claim 2, in addition to the effect of invention of Claim 1, the duct 2 of combustion gas is divided into two combustion gas flow paths by the partition 4, and it is upstream in each said flow path. By providing the side pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34, the flow rates of the combustion gases flowing through the ducts 2 are precisely adjusted up and down individually, and the furnace ( The position at which the flame is formed in 40 can be controlled. When the duct 2 is divided into a plurality of flow paths, the object of measurement and adjustment of the flow rate of the gas for combustion increases, and the flow rate can be actively changed for each flow path, so that fine flow rate adjustment can be performed.

According to invention of Claim 3, in addition to the effect of invention of Claim 1, the fuel nozzle 10 is orthogonal to the center axis direction (flow direction of the fluid which goes to a furnace side exit) which the flow of combustion gas tends to generate | occur | produce easily. Even if the cross-sectional shape is a rectangular shape, an ellipse shape or an ellipse shape having a long diameter part and a short diameter part, the downstream gas pressure detection points 30 and 34 are used as the combustion gas passages in the radial direction based on the central axis of the fuel nozzle 10. By forming on the outer wall surface of the said combustion gas throat 6 which has the largest cross-sectional area, it is hard to be influenced by a drift, and the flow volume of a combustion gas can be measured precisely.

According to the invention described in claim 4, in addition to the effects of the invention described in claim 1, the differential pressure detection devices 32 and 35 are provided to the upstream pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34, respectively. Through the pressure conduits connected to each other, the value of the differential pressure between the upstream pressure and the downstream pressure of the combustion gas in the duct 2 can be detected, which can be realized without causing a significant increase in equipment cost.

According to the invention of claim 5, the flow rate of the solid fuel flowing into the plurality of solid fuel burners 44 of the combustion apparatus is individually measured and measured by the solid fuel flow rate measuring means 71, and the control device 37 is According to the change in the measured solid fuel flow rate, the opening degree of the flow rate adjusting means 1 of the combustion gas is adjusted based on the combustion gas flow rates detected by the differential pressure detection devices 32 and 35 of each solid fuel burner 44. Thus, since the flow rate of the combustion gas is individually controlled, it is possible to quickly cope with a change in the solid fuel flow rate of each burner 44. Moreover, adjustment of only the gas for combustion is carried out, and adjustment means etc. can be made simpler compared with the solid fuel conveyed by a carrier gas. In addition, by varying the amount of gas for combustion above and below the burner 44, the flame can be changed upward or downward in the furnace 40, thereby reducing the nitrogen oxide NOx concentration in the combustion exhaust gas or the boiler furnace 40 The heat transfer amount to the heat exchanger tube (not shown) provided in the inside can be effectively controlled.

1 is a schematic perspective view of a solid fuel burner of an embodiment of the present invention.
2 is a view showing the components of the burner of FIG.
3 is a front view of the combustion air duct seen from the front of the furnace boiler of the burner of FIG.
4 is a cross-sectional view taken along line AA of the burner of FIG. 3.
FIG. 5: is a schematic front view (FIG. 5 (a)) and a side view (FIG. 5 (b)) which show an example of the furnace with the burner of FIG.
6 is a view for explaining the drift of the burner of FIG.
7 is a view for explaining the drift of the burner of FIG.
8 is a view for explaining the drift of the burner of FIG.
9 is a view for explaining the drift of the burner of FIG.
It is a figure explaining the relationship between the damper opening of a burner of FIG. 1, and a positive pressure.
It is a figure explaining the attachment position of the downstream pressure detection point of the burner of FIG.
It is a figure explaining the attachment position of the downstream pressure detection point of the burner of FIG.
It is a figure explaining the influence of the damper opening degree on the static pressure of the attachment position of the downstream pressure detection point of the burner of FIG.
It is a figure explaining the influence of the damper opening degree on the static pressure of the attachment position of the circumferential direction of the downstream pressure detection point of the burner of FIG.
FIG. 15 is a schematic explanatory view of a supply amount control of solid fuel in a furnace using the burner of FIG. 1. FIG.
It is a figure explaining the general combustion air (gas) flow volume measuring method.
It is a figure explaining the general combustion air (gas) flow volume measuring method.

Embodiment of this invention is described with drawing.

In the following examples of the present invention, it is assumed that a solid fuel, particularly pulverized coal or wood biomass, or a mixture of pulverized coal or wood biomass as a main fuel is burned by a solid fuel burner, but the fuel type is not limited thereto. The main fuel may be liquid or gas. In addition, although air is used as a gas for combustion, it is not necessarily limited only to air, You may use recycle gas of combustion exhaust gas, high oxygen concentration gas, mixed gas of the said various gases, etc.

A schematic perspective view of a solid fuel burner which is an embodiment of the present invention is shown in FIG. 1, and a schematic front view in the case of assembling the solid fuel burner 44 to which the present invention is applied to FIG. 5 in a boiler furnace 40 (FIG. 5 (a)). ) And a side view (FIG. 5B).

Combustion air enters into the burner 44 via the combustion air duct 2 shown in FIG. 1 from the wind box 41 provided in the outer side of the side wall of the boiler furnace 40 shown in FIG. It flows out into the furnace 40 from the combustion air throat 6 formed in the opening part of the wall surface. In addition, the pulverized coal and its conveying air are blown into the furnace 40 via the solid combustion conveyance pipe (fuel nozzle) 10 of FIG.

A combustion air throat 6 for ejecting combustion air into the furnace 40 is provided on the outer circumferential side of the solid combustion conveying pipe 10, and the combustion air throat 6 is provided with a combustion air duct ( Air for combustion is supplied from 2). The combustion air duct 2 is provided with an air inlet 8 for guiding combustion air from within the windbox 41, and shows the air inlet direction of the air inlet 8 indicated by arrow B in FIG. The burner 44 is formed in a direction parallel to the furnace wall surface, and is bent at a right angle from the air inlet 8 to blow combustion air into the furnace 40 from the combustion air outlet 7 toward the furnace wall surface. do. Therefore, the combustion air duct 2 is provided in the outer peripheral part of the solid combustion conveying pipe (fuel nozzle) 10, and the air which flowed in from the air inlet 8 substantially surrounds the outer peripheral part of the solid combustion conveying pipe 10. It is bent at a right angle and supplied to the combustion air throat 6.

The outlet portion of the solid combustion conveying pipe 10 has an elliptical structure as seen from the inside of the furnace 40, but the outlet shape of the throat 6 has a circular structure as seen from the inside of the furnace. . Therefore, the furnace outlet of the throat 6 has a large opening up and down around the outlet of the solid combustion conveyance pipe 10.

The combustion air duct 2 is divided into two parts up and down by the center partition 4, and the upper and lower air (combustion gas) do not merge in the combustion duct 2. As shown in FIG. In addition, the combustion air inlet 8 of the combustion air duct 2 is further divided by the upper partition 3 and the lower partition 5 and combined with the space partitioned by the central partition 4. It consists of two spaces, each of which is provided with dampers 1 for adjusting the amount of combustion air (combustion gas).

2 is a detailed perspective view of the combustion air duct 2. The combustion air duct 2 is connected to the combustion air throat 6, but the U-shaped front wall 56 arranged in parallel with the furnace wall surface on the side close to the furnace wall surface and the side far from the furnace wall surface on the rear side thereof. In the U-shaped rear wall 57 and the ridges of the front wall 56 and the rear wall 57 which are arranged in parallel to the front wall 56, both side walls are connected to cover the space of the combustion air duct 2 ( 55). The front wall 56 has a circular opening 58 for connecting the combustion air throat 6, and the side wall member 57 has an opening 59 for connecting the solid fuel conveying pipe 10. have.

The center partition 4 is installed at the position of height 0.5 L1 which is the center position of the height L1 of the said inlet 8 of the combustion air duct 2, and divides the combustion air inlet 8 up and down two times, The spaces in the combustion air duct 2 joined to the front and rear walls 56 and 57 for construction of the duct 2 and divided up and down by the central partition 4 have no inflow or outflow of combustion air. Are independent of each other.

In addition, in the combustion air duct 2 divided up and down by the center partition 4, the upper partition 3 and the lower partition 5 are arrange | positioned, respectively. The upper partition 3 is disposed below the height L3 from the top of the combustion air inlet 8, and the lower partition 5 is installed upward by the height L4 from the bottom of the combustion air inlet 8, respectively. It is arranged in parallel with the central partition 4. Although the said height L3 and the height L4 can be arbitrarily determined, it is necessary to be more than the length of the gas flow direction of the blade | wing of the damper 1.

Although the length L6 in the gas flow direction of the upper partition 3 and the lower partition 5 can also be arbitrarily determined, in order for the combustion air to flow out of the outlet 7 into the furnace 40, the central partition 4 is of length L5. It is necessary to make less. In the present embodiment, although two upper partitions 3 and two lower partitions 5 are used as the partition members, any number can be used.

3 is a front view of the combustion air duct 2 seen from the front of the boiler (front furnace wall of the boiler furnace 40). The radius of curvature r2 of the semicircular portion of the cross section of the side wall 55, which is a constituent member of the combustion air duct 2, needs to be larger than the radius r1 of the combustion air throat 6 (r2 > r1). This has the effect of alleviating the drift in the combustion air outlet 7.

4 is a cross-sectional view taken along the line A-A of FIG. Combustion air 20 introduced into combustion air duct 2 from combustion air (combustion gas) inlet 8 is bent at a right angle, so that combustion air throat 6 and solid fuel conveying pipe 10 It flows through the space between and flows out into the furnace 40 from the combustion air outlet 7. The space between the combustion air throat 6 and the solid fuel conveying pipe 10 is also divided into two parts up and down by the central partition 4 to the combustion air outlet 7. As a result, the amount of combustion air is varied above and below the combustion air outlet 7 and the flame is changed upward or downward, thereby reducing the nitrogen oxide NOx concentration in the combustion exhaust gas or being installed in the boiler furnace 40. It is effective for controlling the amount of heat transferred to a heat transfer pipe (not shown).

The combustion air duct 2 is divided into two parts, up and down, by the central partition 4 to the combustion air outlet 7. By the central partition 4, the amount of combustion air is varied above and below the combustion air outlet 7, and the flame is changed upward or downward in the boiler furnace 40, so that nitrogen oxides NOx in the combustion exhaust gas are changed. It is possible to effectively reduce the concentration and to control the amount of heat transfer to the heat transfer pipe (not shown) provided in the boiler furnace 40.

The flow rate of the combustion air in the combustion air duct 2 divided into two parts up and down with the central partition 4 interposed between the upstream pressure detection point 31 and the downstream pressure detection point 30, which are pressure conduits, respectively. The deviation of the pressure measurement value and the deviation of the pressure measurement value between the upstream pressure detection point 33 and the downstream pressure detection point 34 are measured.

The upstream pressure detection points 31 and 33, which are pressure conduits for measuring the flow rate of the combustion air, are attached to the stagnant region 90 (Fig. 3) of the combustion air duct 2. Here, the stagnant region 90 is a region that appears in the region 90 represented by the painted portion in FIG. 2 and the oblique portion in FIG. 3, and passes through the center of the opening 58 to define a central axis of the air throat 6 for combustion. A space surrounded by the front and back walls 56 and 57 and the side wall 55 with an imaginary surface formed with the inclination angles θ ₁ and θ ₂ with respect to the horizontal plane above and below with the center partition 4 interposed as the origin. ), And upstream pressure detection points 31 and 33, which are pressure conduits, can be arbitrarily attached to the stagnant region 90. The values of the inclination angles θ1 and θ2 will be described later.

In addition, the downstream pressure detection points 30 and 34 which are the other pressure conduits are positions where the difference between the radius r1 of the combustion air throat 6 and the exit radius r3 of the solid fuel conveying pipe 10 becomes the maximum. It is provided in the top part and the bottom part of the combustion air throat 6, respectively. The downstream pressure detection points 30 and 34 are perpendicular to the longitudinal direction of the downstream pressure detection points 30 and 34 with respect to the wall surface of the combustion air throat 6 shown in FIG. 1 so as not to be affected by dynamic pressure. It is attached so as to face in the direction.

From the upstream pressure detection points 31 and 33, an upstream fluid pressure (high pressure side pressure) of the combustion air flowing in the combustion air duct 2 is derived, and from the downstream pressure detection points 30 and 34. Is the downstream fluid pressure (low pressure side pressure) of the combustion air. The upstream and downstream side pressure detection points 30 and 31, which are pressure conduits, are connected to the differential pressure detection device 32, and the upstream and downstream side pressure detection points 33 and 34 are connected to the differential pressure detection device 35, and the differential pressure thereof is described above. Is substituted into the predetermined flow rate conversion equation (1) to calculate the flow rate of the combustion air.

The material and diameter of the pressure conduit constituting the upstream and downstream pressure detection points 30, 31, 33, and 34 may be any ones, but the material needs to consider the temperature of the combustion air (about 300 ° C). . In addition, the diameter of the pressure conduit constituting the upstream and downstream pressure detection points 30, 31, 33, 34 needs to consider the clogging caused by dust contained in the combustion air, and it is also effective to apply a purge system or the like.

5 is a schematic view of the furnace 40 using the burner 44 incorporating the present invention. A wind box 41 is provided in the furnace 40, and a plurality of two-stage combustion air (combustion gas) ports 42 and a burner 44 to which the present invention is applied are provided. The solid fuel supplied from the outside of the furnace 40 is connected to each burner 44 from the solid fuel conveying pipe 10.

In FIG. 5, although the burner 44 is shown in front of the boiler 40 of the furnace 40, the present invention can be used also for the counter combustion burner etc. which were provided in the boiler front of the furnace 40, and the back of a boiler. have. 5 shows an example in which two stages of the two-stage combustion air (combustion gas) ports 42 are provided, but the number of stages can be applied in one stage, and in FIG. 5, the six ports 42 in a row. ), But you can set any number.

16 and 17 show examples of the flow rate measuring device of the combustion air (combustion gas) that is used for general purposes. FIG. 16 shows an example of a flow rate measuring device using a pitot tube 61. The pitot tube 61 is provided in the flow path 60 toward the inlet of the whole pressure detection hole 62 in the direction which opposes the flow 22 of a fluid. The fluid pressure detected by the total pressure detecting hole 62 and the static pressure detecting hole 63 is sent to the differential pressure detecting device 67, and substituted into the predetermined flow rate conversion equation (1) to calculate the flow rate.

17 is an example of a flow rate measuring device for combustion air (combustion gas) using an orifice. The orifice 64 is attached in the direction perpendicular to the flow 22 of the fluid in the flow path 60. The pressure conduits 65 and 66 are provided on the upstream side and the downstream side with the orifice 64 interposed therebetween. The fluid pressure detected by the pressure conduits 65 and 66 is sent to the differential pressure detection device 67, and substituted into the predetermined flow rate conversion equation (1) to calculate the flow rate.

In the pitot pipe 61, the sufficient straight pipe length required in the burner 44 is not taken, and the measurement accuracy of fuel flow rate is low, and it is likely to be affected by the drift. Although many pitot pipes 61 are used and the cross section in the flow path 60 can be measured in several places, flow measurement accuracy can be made high, but it is difficult to cost. In addition, when the orifice 64 is used, excess pressure loss occurs because of the flow rate measurement, and the power of the fan or the like for conveying the combustion air to each burner 44 increases, which is not preferable.

With respect to the general-purpose flow rate measuring device, the flow rate measuring device of the present invention measures the pressure loss of the combustion air (gas) due to the burner structure to the upstream and downstream pressure detection points 30 and 31 and the differential pressure detecting device 32 or upstream and downstream. By detecting by the side pressure detection points 33 and 34 and the differential pressure detection apparatus 35, respectively, and converting into the combustion air (gas) flow volume, the extra pressure loss for a flow measurement does not arise. In addition, by selecting an appropriate differential pressure detection position, the detected differential pressure is not influenced by changes in flow patterns and drift caused by operating the damper 1 for adjusting the amount of combustion air.

Next, the drift of the burner combustion air will be described.

6 is a vertical line which can be obtained by connecting the rotary shafts 1a, 1b, 1c and 1d of the plurality of adjustment dampers 1 arranged in parallel near the combustion air inlet 8 of the combustion air duct 2 ( 52 is a view of the burner 44 when the angle δ formed by the combustion air amount adjusting damper 1 is 30 ° from the front of the boiler, and FIG. 7 schematically shows the flow rate variation of the combustion air outlet 7. It is shown as.

The air volume adjustment damper 1 for combustion has the space 50a divided into the side wall 55 and the upper partition 3, the space 50b divided into the upper partition 3, and the center partition 4, and the center partition ( Dampers 1a, 1b, 1c, and 1d are attached to the space 50c, which is divided into 4) and the lower partition 5, and the space 50d, which is divided into the lower partition 5 and the side walls 55, respectively.

In FIG. 6, the angle δ formed between the vertical line 52 and the extension line 53 of the blade of the damper 1 is 30 ° (damper opening degree 30 °). The flow 21 of combustion air in the combustion air duct 2 at this time differs in the flow volume shown in FIG. As shown in FIG. 7, the flow rate increases in the region (b) of the combustion air outlet 7, and the flow rate is small in the region (a) of the outlet 7. The flow rate is small in the region (C) of the outlet 7, and the flow rate is large in the region (D) of the outlet 7. This is the drift of the combustion air.

8 and 9 show the burner 44 when the angle δ formed between the vertical line 52 and the extension line 53 of the damper 1 for adjusting the amount of combustion air is 90 ° (damper opening degree 90 °) from the front of the boiler. This figure and the flow rate variation of the combustion air outlet 7 are shown typically. By changing the angle δ, the flow 21 of combustion air is different from the case where the damper opening degree of FIG. 6 is 30 degrees. Therefore, unlike the case where the flow rate variation of the combustion air outlet 7 and the damper opening degree are 30 degrees, the flow rate variation becomes large in the region (b) of the combustion air outlet 7 and the region (c) of the outlet 7, It becomes small in the area | region (a) of the exit 7 and the area | region (c) of the exit 7.

Since the damper 1 is automatically controlled to set the burner air ratio to a predetermined value, the upstream and downstream pressure detection points 30, which are pressure conduits, are not affected by the angle δ formed between the vertical line 52 and the damper 1. 31; 33, 34 are preferred. The upstream pressure detection points 31 and 33 need to be provided in the stagnant region 90 (FIGS. 2 and 3) without the influence of the axial flow of the damper 1.

The result of examination using the full scale model is shown in FIG. The horizontal axis represents the opening degree (%) of the damper 1 for adjusting the amount of combustion air with respect to the vertical line 52 in FIGS. 6 and 8, and the vertical axis represents the ratio of the static pressure to burner pressure loss at the same flow rate (dimensionless). to be. In the range of angles which appear in the range of stagnation region 90 shown in FIG. 3 θ _1, θ ₂ is θ1 = θ2≤15 °, the said angle range of θ _1, θ _2, which is actually used, the static pressure The value of burner pressure loss is nearly constant. This is because the flow velocity is almost zero, and the angles θ ₁ and θ ₂ were defined as the stagnant region 90 in the range of θ ₁ = θ ₂ ≦ 15 °. Therefore, the upstream pressure detection points 31 and 33 can be provided in arbitrary positions of the side wall 55 which is a structural member of the combustion air (combustion gas) duct 2 contained in this range.

Next, the positions of the downstream pressure detection points 30 and 34 which are pressure conduits are examined. It is necessary to provide downstream pressure detection points 30 and 34 in the region which is not affected by the drift of the combustion air (gas) shown in FIGS. 6 to 9.

FIG. 11: is a schematic diagram which shows the attachment position 81-83 of the downstream pressure detection point 30 of the combustion air throat 6 in the center axis direction, and FIG. 12 is a figure of the said throat 6, FIG. It is a schematic diagram which instruct | indicates the attachment position 84-87 of the downstream pressure detection point 30 of a circumferential direction. The downstream side pressure detecting point attachment positions 81 to 83 (Fig. 11) are in the radial direction.

(Radius r1 of throat 6)-(Radius r3 of fuel nozzle 10)

Is provided on the up-state combustion air throat (6) is in, the downstream pressure detection point attachment location 82, the intermediate length (0.5 × L ₁₀₎ of the length L ₁₀ of the said throat (58) (6) The downstream side pressure detection point attachment position 81 is provided downstream, and the downstream side pressure detection point attachment position 83 is provided upstream of the said throat 6. . In addition, as shown in FIG. 12, the downstream side pressure detection point attachment positions 84,85,86,87 are provided in the intermediate position of the length of the center 6 direction of the said throat 6, and a downstream pressure detection point attachment is provided. The positions 85 and 86 are the inclination angles θ ₃ = 2 ° in the radial direction of the throat 6 with respect to the vertical line passing through the central axis of the throat 6, and the position with the downstream pressure detection point 84 Denotes the inclination angle θ ₃ = 20 ° in the radial direction of the throat 6.

13 and 14 show the results of the examination using the full-size model. The horizontal axis of FIG. 13 and FIG. 14 is an angle (damper opening degree) which the vertical line 52 of FIG. 6, FIG. 8 and the damper 1 for combustion air (combustion gas) quantity adjustment make, and the vertical axis | shaft in the same flow volume Positive pressure / burner pressure loss.

According to FIG. 13, the static pressure is substantially constant within the damper opening degree range to be used in the downstream pressure detection point attachment positions 81 and 82 in the direction of the center axis of the throat 6. According to FIG. 14, in the circumferential direction of the said throat 6, in the circumferential direction of the downstream pressure detection point (82, 85, 86), the positive pressure / burner within the range of about 10 to 80% of the damper opening degree range to be used. The pressure loss is almost constant. Although the static pressure / burner pressure loss is slightly different within the damper opening degree range to be used, the differential pressure detected by the differential pressure detection devices 32 and 35 of the burner shown in FIG. Is less.

Thus, the range of the attachment position of the downstream pressure detection points 30 and 34 in the burner shown in FIG. 1 makes PL into an attachment position regarding the center-axis direction of the said throat part 6, the switch from the center point of the length L of the funnel (6) is attached to the range on the downstream side of 0.5L ₁₀ ≤PL≤L _10. The circumferential direction of the said throat 6 shall be affixed in the range of 0 degrees <= (theta) ₃ = (theta) _{4 <} = 2 degrees shown in FIG.

FIG. 15 is a view for explaining the solid fuel measuring means. The solid fuel is pulverized to a predetermined particle size by a solid fuel pulverizing device 70 (for example, a grinding mill or the like). The burner 44 is conveyed by the conveying gas through the solid fuel conveying pipe 10. The solid fuel conveying pipe 10 is provided with a solid fuel measuring means 71 (for example, there are measuring devices such as electrostatic charge type and microwave type). In this way, the flow rate of the solid fuel flowing into the plurality of solid fuel burners 44 of the combustion device is individually measured and measured by the solid fuel flow rate measuring means 71, and the control device 37 measures the solid fuel flow rate measured. In accordance with the change of the combustion, the opening degree of the flow rate adjusting means 1 of the combustion gas is adjusted based on the flow rate of the combustion gas detected by the differential pressure detection devices 32 and 35 of the respective solid fuel burners 44. Since the flow rate of the gas is individually controlled, it is possible to quickly cope with a change in the solid fuel flow rate of each burner 44.

In addition, control of a burner load is sufficient only by adjustment of the gas for combustion, and it can make simple adjustment means etc. compared with the solid fuel conveyed by carrier gas. In addition, by varying the amount of combustion gas in the furnace 40 up and down of the burner 44, the flame can be changed upward or downward, thereby reducing the nitrogen oxide NOx concentration in the combustion exhaust gas or the boiler furnace 40 The heat transfer amount to the heat exchanger tube (not shown) provided in the inside can be effectively controlled. In addition, the central partition 4 divides the combustion air outlet 7 up and down by two, so that the amount of combustion air is varied above and below the combustion air outlet 7 to cause the flame in the boiler furnace 40. By changing the direction upward or downward, it is possible to effectively reduce the nitrogen oxide NOx concentration in the combustion exhaust gas and control the amount of heat transfer to a heat transfer pipe (not shown) provided in the boiler furnace 40.

In the present Example, the burner structure was demonstrated using the fuel nozzle 10 of a flat cross section. In the present invention, not only the flat shape but also the fuel nozzle 10 having a circular cross section can use the above-described measurement method.

When the cross section of the fuel nozzle 10 is circular, the cross-sectional shape of the combustion air outlet 7 formed by the fuel nozzle 10 and the combustion air throat 6 is concentric, and thus compared with the flat shape. No drift occurs.

However, the combustion air which flowed in from the combustion air inlet 8 is not necessarily discharged | emitted from the combustion air throat 6 uniformly concentric in the combustion air duct 2.

The case where the fuel nozzle 10 is made into the fuel nozzle 10 of circular cross section is demonstrated using FIG. The air which flows in from the combustion air inlet 8 flows by the adjustment damper 1. When the angle δ formed between the vertical line 52 in FIG. 6 and the extension line 53 of the blade of the damper 1 is 30 °, the air flows downward in the vertical direction, so that the combustion is close to the downstream of the damper 1 for adjustment. The air flow rate from the air outlet 7 increases.

As described above, even if the cross-sectional shape of the fuel nozzle 10 is flat or circular, a variation occurs in the air flow rate of the air outlet 7 for combustion.

Next, the upstream pressure detection point of the fuel nozzle 10 having a circular cross section (not shown, but the cross section of FIG. 1 corresponds to the upstream pressure detection points 31 and 33 of the flat fuel nozzle 10). The installation position will be described. As described above, the circular fuel nozzle 10 is also affected by the drift caused by the opening degree of the damper 1 similarly to the flat fuel nozzle 10.

Since the attachment position PL of the upstream pressure detection point is the same as that of the flat fuel nozzle 10 of FIG. 11, it demonstrates using FIG. With respect to the length L ₁₀ of the air an axial flow, the throat (6) to avoid the influence of it flows toward the air throat (6) for burning combustion from for a pneumatic duct (2) shown in Figure 11 in the direction in which the air flowing 0.5 L ₁₀ ≤PL≤L the range of ₁₀ and preferably, as shown in the mounting position θ _3, θ4 is 12 in the circumferential direction, is 0 ° ≤θ ₃ = θ4≤2 ° range is preferred. This is because the change of the static pressure at the upstream pressure detection point is hardly within the damper opening degree range. Therefore, in the case of the fuel nozzle 10 having a circular cross section, it is preferable to provide an upstream pressure detection point in the same range as in the case of the flat fuel nozzle 10.

In addition, the downstream pressure detection point (it corresponds to downstream pressure detection points 30 and 34 provided in the flat fuel nozzle 10 shown in FIG. 1, and is demonstrated using FIG. 1) is a combustion gas switch. Downstream pressure detection points are arranged on the top wall and the bottom wall of the lot 6, respectively. The combustion gas throat in the center axis direction within a range of ± 2 ° (see FIG. 12) in the circumferential direction with reference to the government of the throat 6 of the combustion gas, which is a location where the downstream pressure detection point is disposed. It exists in the side (refer FIG. 11) downstream from the half length of the throat length of 6). In addition, since downstream pressure detection points are arranged on the top wall and the bottom wall of the combustion gas throat 6, the gas flow rate for combustion can be measured without being influenced by the drift of the combustion gas. The flow rate measurement of can be performed with high accuracy.

In addition, the fuel nozzle 10 having a circular cross section is also provided with a differential pressure detection device corresponding to the differential pressure detection devices 32 and 35 shown in FIG. 1, although not shown in the figure, and an upstream pressure detection point and a downstream pressure detection point. The control device which converts the value of the pressure difference in into the flow volume of combustion gas, and adjusts the amount of combustion air inflow into a combustion air duct by damper operation is also provided.

Next, the case where there is no center partition 4 of the burner provided with the fuel nozzle 10 whose cross section is flat or circular is demonstrated.

In the above-mentioned embodiment, the combustion air duct 2 was completely divided into two parts up and down, and the measurement points of the combustion air needed to be installed in two places of the combustion air duct 2 divided into the upper side and the lower side, respectively. . However, when there is no center partition 4, the measurement points corresponding to the pressure detection points 30, 31, 33, 34 in Fig. 1 are reduced to one place. Regarding the installation position of the pressure detection point, it is necessary to install it at a position where the influence of the drift of the damper 1 does not occur.

Here, the influence of the drift of the combustion air by the opening degree of the damper 1 is assumed. The installation position of the downstream pressure detection point (not shown, corresponds to the downstream pressure detection points 30 and 34 in Fig. 1) will be examined. In the combustion air outlet 7 on the left side of the combustion air outlet 7 in the region (b) or region (c) of FIG. 9, that is, near the combustion air inlet 8, the damper 1 It is not suitable because it is affected by the drift caused by). On the other hand, also on the right side of the combustion air outlet 7, that is, the far side from the combustion air inlet 8 (areas (a) and (d)), the flow rate deviation of the zone (b) and the zone (c) By the influence of, the air flow rate differs based on the opening degree of the damper 1. In the stationary part of the combustion air throat 6, there is no flow rate variation by the damper 1, and there is little unbalance in the top and bottom, so that the flow rate variation is small regardless of the opening degree of the damper 1.

Therefore, the downstream pressure detection point (not shown) may be attached to the top or bottom of the combustion air throat 6. In consideration of maintenance property and easy attachment, it is better to attach to the above-mentioned government.

In addition, the attachment position of an upstream pressure detection point (not shown) becomes one place. When there existed the center partition 4, the stagnant space 90 (refer FIG. 2) in the combustion air duct 2 of each of the upper side and the lower side was provided in the downstream. Even when there is no center partition 4, since most of the combustion air flows out into the throat 6 before reaching the downstream of the combustion air duct 2, there is a stagnant area with little flow of combustion air. . In the stagnant region, the static pressure is stabilized regardless of the opening degree of the damper 1. Therefore, one downstream pressure detection point is provided in the area | region in which the pressure detection points 30 and 34 were provided in the most downstream of the combustion air duct 2 in FIG.

In the case where the combustion air duct 2 is divided up and down by the central partition 4, the center of the duct (the semi-circular part of the combustion air duct 2) where the central partition 4 and the combustion air duct 2 intersect is In the position farthest from the combustion air inlet 8, the static pressure is most stable even within the stagnant region. Therefore, the upstream detection point is preferably a part of the semicircular portion of the combustion air duct 2 (a position corresponding to the upstream pressure detection points 31 and 33 in FIG. 1).

1: damper for adjusting air flow rate for combustion 2: air duct for combustion
3: upper partition 4: bulkhead (center partition)
5: lower partition 6: air throat for combustion
7 combustion air outlet 8 combustion air flow inlet
10: solid fuel return pipe (fuel nozzle) 11: return air, fuel outlet
20 ~ 22: Air flow 31, 33: Upstream pressure detection point
30, 34: downstream pressure detection point 32, 35: differential pressure detection device
37: control device 40: brazier
41: Windbox 42: Air port for two stage combustion
44: burner
50: space where the air duct for combustion is divided
52: vertical line 53: extension line of the blade of the damper
55: side wall 56, 57: front wall
58: opening for air (gas) throat connection for combustion
59: opening for connecting the combustion conveying pipe
60: Euro 61: pitot tube
62, 63, 65, 66: pressure conduit 64: orifice
67 differential pressure detection device 70 solid fuel grinding device
71: solid fuel flow measurement means
81 ~ 87: Position of downstream pressure detection point
90: congestion area

Claims (5)

A cylindrical fuel nozzle 10 which ejects the mixed fluid of the solid fuel and the conveying gas into the furnace 40 from the wall surface of the furnace 40,
A cylindrical combustion gas throat 6 provided on an outer circumference of the fuel nozzle 10 to blow off combustion gas into the furnace 40;
A duct 2 constituting a flow path of the combustion gas connected to the combustion gas throat 6;
A flow rate adjusting means 1 of the gas for combustion installed in the duct 2,
A solid fuel burner having differential pressure detection devices (32, 35) for detecting a pressure difference between combustion gases flowing upstream and downstream in the duct (2),
The duct 2 has an inlet port 8 that is blown in from one direction orthogonal to the central axis direction of the fuel nozzle 10, and a flow path of the combustion gas is perpendicular to the central axis direction of the fuel nozzle 10. Is formed to be bent,
The flow rate adjusting means 1 of the combustion gas is provided near the inlet 8 of the duct 2, and is provided downstream of the inlet 8,
The differential pressure detecting devices 32 and 35 are located on the wake side of the flow rate adjusting means 1 from the inlet 8 of the duct 2 corresponding to the stagnant region 90 of the combustion gas. It has upstream pressure detection points 31 and 33 on the inner wall of the duct 2 which is furthest away, and has downstream pressure detection points 30 and 34 on the outer wall of the gas throat 6 for combustion,
The value of the pressure difference at the upstream pressure detection points 31 and 33 and the downstream pressure detection points 30 and 34 detected by the differential pressure detection devices 32 and 35 is converted into the flow rate of the gas for combustion, and And a control device (37) for controlling the flow rate of the gas for combustion by operating the flow rate adjusting means (1). 2. The flow path of the combustion gas in the duct 2 connected to the combustion gas throat 6 is divided into a plurality of flow paths through which the gas for mutual combustion is not introduced by the partition wall. Become,
And the upstream pressure detection point (31,33) and the downstream pressure detection point (30,34) are provided in each of the plurality of flow paths. The combustion gas throat (6) according to claim 1, wherein the downstream pressure detection points (30, 34) are spaced apart from each other in the radial direction of the gas flow path in the radial direction with respect to the central axis of the fuel nozzle (10). Solid fuel burner). The pressure difference detecting device (32, 35) according to claim 1, wherein the differential pressure detecting device (32, 35) is formed through the pressure ducts forming the upstream pressure detecting points (31, 33) and the downstream pressure detecting points (30, 34). 2) A solid fuel burner characterized by detecting a value of a differential pressure between an upstream pressure and a downstream pressure of a combustion gas in 2). A combustion apparatus comprising a plurality of rows of the solid fuel burner (44) according to claim 1 in the vertical direction of the wall surface of the furnace (40) and a plurality of rows in the furnace width direction.
It is provided with a solid fuel flow rate measuring means 71 for individually adjusting and measuring the flow rate of the solid fuel flowing into the plurality of solid fuel burners 44,
The control device 37 is a combustion gas flow rate detected by the differential pressure detection devices 32 and 35 of each solid fuel burner 44 according to the change of the solid fuel flow rate measured by the solid fuel flow rate measuring means 71. And a configuration for individually adjusting the opening degree of the flow rate adjusting means (1) of the gas for combustion and individually controlling the flow rate of the gas for combustion.

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