KR102339892B1 - Reductant supply device and method for operating reductant supply device - Google Patents

Abstract

(Task) Suppress the imbalance of the local concentration distribution of the reducing agent due to the influence of drift caused by the obstacle.
(Solution Means) A reducing agent supply device for supplying a reducing agent upstream of the SCR catalyst in the exhaust gas flow path in which the obstacle is disposed, downstream of the obstacle in the exhaust gas flow direction, intersects the flow direction of the exhaust gas A plurality of spray nozzles arranged at intervals along one direction and a plurality of reducing agent supply lines for supplying a reducing agent to the plurality of spray nozzles are provided. Among the plurality of injection nozzles, when the injection nozzle located downstream of the obstacle is defined as the first injection nozzle and the injection nozzle not located downstream of the same is defined as the second injection nozzle, the plurality of injection nozzles have the same reducing agent supply line A plurality of injection nozzle groups including at least one injection nozzle to which a reducing agent is supplied by It is divided into a plurality of injection nozzle groups including the injection nozzle group.

Description

A reducing agent supply device, and the operating method of the reducing agent supply device TECHNICAL FIELD

The present disclosure relates to a reducing agent supply device and a method for operating the reducing agent supply device.

Conventionally, for example, in order to remove NOx from combustion exhaust gases such as fossil fuels, a reducing agent such as ammonia is mixed into the exhaust gas and a denitration catalyst (eg, SCR catalyst, etc.) is used to promote the reaction. The device is known. For example, in Patent Document 1, ammonia injection configured to uniformly distribute ammonia ejected from the nozzle in the exhaust gas by changing the direction and angle of a nozzle attached to the ammonia supply pipe along the shape of the exhaust gas flow path of the exhaust gas duct. An apparatus is disclosed.

Japanese Patent Laid-Open No. 9-24246

By the way, the denitration catalyst as described above is disposed over substantially the entire width of the exhaust gas flow path. For this reason, in order to make the concentration distribution of the reducing agent uniform in the width direction of the exhaust gas flow path and to allow the catalyst to pass through, a plurality of nozzles may be arranged in the ammonia supply pipe at intervals in the extending direction of the supply pipe. On the other hand, upstream of the ammonia supply pipe in the flow path, various obstacles including pipes and struts may be disposed. Since a local drift occurs downstream of such an obstacle, the concentration distribution of the reducing agent in the said width direction becomes non-uniform|heterogenous downstream of an obstacle, and there exists a possibility that the nitrogen removal performance of a nitrogen removal catalyst may fall.

In this regard, Patent Document 1 does not disclose knowledge about the unbalance of the concentration distribution of the reducing agent due to the influence of drift due to the presence of an obstacle located upstream of the ammonia supply pipe.

In view of the circumstances described above, at least one embodiment of the present invention provides a reducing agent supply device capable of suppressing an imbalance in the local concentration distribution of a reducing agent due to the influence of drift caused by an obstacle, or a method of operating a reducing agent supply device aim to do

(1) A reducing agent supply device according to at least one embodiment of the present invention,

A reducing agent supply device for supplying a reducing agent upstream of an SCR catalyst in an exhaust gas flow path having an obstacle disposed therein, comprising:

a plurality of injection nozzles disposed at intervals along one direction intersecting with respect to the flow direction of the exhaust gas downstream of the obstacle in the flow direction of the exhaust gas;

and a plurality of reducing agent supply lines configured to supply the reducing agent to the plurality of spray nozzles,

Among the plurality of injection nozzles, when the injection nozzle located downstream of the obstacle is defined as the first injection nozzle and the injection nozzle not located downstream of the obstacle is defined as the second injection nozzle,

The plurality of injection nozzles are a plurality of injection nozzle groups including at least one injection nozzle configured to supply the reducing agent through the same reducing agent supply line, and the first injection nozzle group including the first injection nozzle It is divided into a nozzle group and a plurality of spray nozzle groups including a second spray nozzle group, which is the spray nozzle group including the second spray nozzle.

According to the configuration of (1) above, the plurality of injection nozzles arranged along one direction intersecting the flow direction of the exhaust gas in the flow path of the exhaust gas comprises a first injection nozzle located downstream of the obstacle. The first injection nozzle group and the injection nozzle group including the second injection nozzle not located downstream of the obstacle are divided, and a reducing agent is supplied to each injection nozzle group through the same reducing agent supply line. Thereby, the injection amount of the reducing agent injected from the 1st injection nozzle group including the 1st injection nozzle located downstream of an obstacle can be adjusted independently from the 2nd injection nozzle group. Therefore, even if a drift occurs downstream of the obstacle due to the existence of the obstacle, if the amount of the reducing agent supplied to the first injection nozzle group is appropriately adjusted, the exhaust gas generated downstream of the injection nozzle group due to the drift is It is possible to suppress the imbalance of the local concentration distribution of the reducing agent in one direction intersecting the flow direction. That is, it is possible to provide a reducing agent supply device capable of suppressing the imbalance of the local concentration distribution of the reducing agent due to the influence of the drift caused by the obstacle.

(2) In some embodiments, in the configuration of (1) above,

The number of the first injection nozzles included in one of the first injection nozzle groups is smaller than the number of the second injection nozzles included in the one second injection nozzle group.

According to the configuration of (2), since the ratio of the first injection nozzle group to the flow path cross-sectional area of the exhaust gas flow path is smaller than that of the second injection nozzle group, the second injection nozzle group cannot cope with the ratio of the flow path cross-sectional area. The influence on the concentration distribution of the local reducing agent by this small obstacle (eg, a thin pipe or a strut, etc.) can be more finely suppressed, and the concentration distribution can be uniformed.

(3) In some embodiments, in the configuration of (1) or (2) above,

As the width (W) of the flow path in the one direction and the width (D) of the obstacle in the flow direction, the distance (L) between the obstacle and the first injection nozzle group in the flow direction is , the following formula (i) or (ii) may be satisfied.

L ≤ 2W … (i)

L ≤ 20D … (ii)

At a position sufficiently far downstream from the obstacle, the influence of the wake of the obstacle is small, and the concentration distribution of the reducing agent in one direction intersecting the flow direction of the exhaust gas becomes close to uniform, so that the injection nozzle group can be locally classified. need is diminished. On the other hand, in a position where the distance between the obstacle and the spray nozzle group is close and the influence of the wake is significant, the imbalance of the local concentration distribution can be effectively reduced by locally dividing the spray nozzle group.

In this regard, according to the configuration of (3) above, by arranging the first jet nozzle group at a position that satisfies the relationship of (i) or (ii), where the influence of the wake of the obstacle is large, (1) or (2) ), you can enjoy the effects described in

(4) In some embodiments, in the configuration in any one of (1) to (3),

The plurality of injection nozzles may be discretely arranged over the entire width of the flow path.

According to the structure of said (4), the concentration distribution of a reducing agent can be equalized|homogenized over the entire width of the flow path of exhaust gas. Therefore, for example, in the case where the reducing agent supply device is disposed upstream of the SCR catalyst formed over the entire width of the flow path, the effect described in (1) can be maximized to maximize the denitration performance of the SCR catalyst. have.

(5) In some embodiments, in the configuration in any one of (1) to (4),

The reducing agent supply device,

a concentration sensor disposed downstream of the plurality of injection nozzle groups in the flow direction to measure a concentration distribution of the reducing agent in the exhaust gas in the one direction;

A plurality of flow control valves formed corresponding to each of the plurality of reducing agent supply lines and a plurality of valve actuators capable of independently changing the respective opening degrees of the plurality of flow control valves;

You may further comprise a controller which drives the said valve actuator so that the concentration distribution of the said reducing agent in the said one direction may be equalized according to the detection signal of the said density|concentration sensor.

According to the configuration of (5) above, in response to the detection signal from the concentration sensor, the controller can feedback control each valve actuator to equalize the concentration distribution of the reducing agent in one direction intersecting the flow direction of the exhaust gas. Thereby, for example, the concentration distribution of the reducing agent in one direction intersecting with the flow direction of the exhaust gas can be equalized in real time, without requiring an operation for adjusting the opening degree of individual valves by an operator.

(6) A method of operating a reducing agent supply device according to at least one embodiment of the present invention,

A method of operating a reducing agent supply device for supplying a reducing agent upstream of an SCR catalyst in an exhaust gas flow path having an obstacle disposed therein, comprising:

The reducing agent supply device,

a plurality of injection nozzles disposed at intervals along one direction intersecting with respect to the flow direction of the exhaust gas downstream of the obstacle in the flow direction of the exhaust gas;

and a plurality of reducing agent supply lines configured to supply the reducing agent to the plurality of spray nozzles,

Among the plurality of injection nozzles, when the injection nozzle located downstream of the obstacle is defined as the first injection nozzle and the injection nozzle not located downstream of the obstacle is defined as the second injection nozzle,

The plurality of injection nozzles are a plurality of injection nozzle groups including at least one injection nozzle configured to supply the reducing agent through the same reducing agent supply line, and the first injection nozzle group including the first injection nozzle It is divided into a plurality of spray nozzle groups including a nozzle group, and a second spray nozzle group that is the spray nozzle group including the second spray nozzle,

The operating method of the reducing agent supply device,

measuring the concentration distribution of the reducing agent or NOx in the one direction downstream of the plurality of injection nozzles in the flow direction of the exhaust gas;

and individually adjusting the amounts of the reducing agent supplied to the first injection nozzle group and the second injection nozzle group according to the measurement result of the concentration distribution.

According to the method of (6), as described in (1) above, a plurality of injection nozzles arranged along one direction intersecting with the flow direction of the exhaust gas in the flow path of the exhaust gas are disposed downstream of the obstacle. It is divided into a first spray nozzle group including a first spray nozzle positioned and a spray nozzle group including a second spray nozzle that is not located downstream of the obstacle, and each spray nozzle group has a reducing agent through the same reducing agent supply line. is supplied Thereby, the injection amount of the reducing agent injected from the 1st injection nozzle group including the 1st injection nozzle located downstream of an obstacle can be adjusted independently from the 2nd injection nozzle group. Therefore, even if a drift occurs downstream of the obstacle due to the existence of the obstacle, if the amount of the reducing agent supplied to the first injection nozzle group is appropriately adjusted, the exhaust gas generated downstream of the injection nozzle group due to the drift is It is possible to suppress the imbalance of the local concentration distribution of the reducing agent in one direction intersecting the flow direction. That is, it is possible to provide a method of operating a reducing agent supply device capable of suppressing the imbalance of the local concentration distribution of the reducing agent due to the influence of drift caused by the obstacle. Further, as described in (5) above, the first injection nozzle group and the second injection nozzle group according to the concentration distribution of the reducing agent in one direction intersecting the flow direction of the exhaust gas measured downstream of the plurality of injection nozzles The amount of reducing agent supplied to the group can be individually adjusted. Thereby, for example, the concentration distribution of the reducing agent in one direction intersecting the flow direction of the exhaust gas can be made uniform without requiring an operation for adjusting the opening degree of the individual injection nozzles by the operator.

According to at least one embodiment of the present invention, it is possible to provide a reducing agent supply device capable of suppressing imbalance in the local concentration distribution of the reducing agent due to the influence of drift caused by an obstacle, and a method for operating the reducing agent supply device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the downstream side of the exhaust gas flow path of the boiler system to which the reducing agent supply apparatus which concerns on one Embodiment of this invention is applied.
Fig. 2 is a side cross-sectional view schematically showing the configuration of a reducing agent supply device according to an embodiment.
FIG. 3 is a diagram schematically showing the configuration of a reducing agent supply device according to an embodiment, and is a partially enlarged view of part III shown in FIG. 2 .
Fig. 4 is a side cross-sectional view schematically showing adjustment of the concentration of the reducing agent by the reducing agent supply device according to the embodiment.
5 is a block diagram showing the configuration of a control system in the reducing agent supply device according to the embodiment.
6 is a flowchart showing a reducing agent supply method according to at least one embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to an accompanying drawing, some embodiment of this invention is described. However, the dimensions, materials, shapes, relative arrangements, and the like of components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, and are merely illustrative examples.

For example, expressions indicating a relative or absolute arrangement such as “in any direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly It is assumed that not only the arrangement is indicated, but also the state in which the tolerance is relatively displaced with an angle or distance sufficient to obtain the same function.

Also, for example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in a geometrically strict sense, but also include irregularities or chamfers within the range where the same effect is obtained. It is assumed that the shape including the shape is also shown.

On the other hand, the expressions "prepare", "equip", "include", "include", or "have" one component are not exclusive expressions excluding the existence of other components.

1 is a schematic diagram showing the configuration of an exhaust gas flow path downstream of a boiler system to which a reducing agent supply device 10 according to at least one embodiment of the present invention is applied.

In addition, the following description demonstrates the case where the denitration apparatus 1 is arrange|positioned in the exhaust gas flow path 2 of a coal-fired boiler (boiler 4) as an example. The boiler 4 is provided with the furnace 5 and combustion apparatus (not shown) shown in FIG. 1, and the flue 6 connected to the exhaust gas flow path 2 .

As shown in FIG. 1 , the denitration device 1 is disposed on the downstream side of the exhaust gas flow path 2 of the boiler system 100 . This denitration device 1 is disposed on the downstream side in the exhaust gas flow path 2 that guides the exhaust gas G discharged from the boiler 4 in a direction intersecting the flow direction of the exhaust gas G (that is, the exhaust gas The SCR catalyst 3 arranged so as to extend along the width direction of the flow passage 2), and the reducing agent 8 (for example, anhydrous ammonia; A reducing agent supply device 10 for supplying ammonia water, urea, urea water, or a mixed gas of at least one of these and air) is provided. In the following description, as an example of the reducing agent 8, ammonia (more specifically, a mixed gas of ammonia and air) is sprayed into the exhaust gas G. As shown in FIG.

The SCR catalyst 3 is a denitration catalyst used in a selective catalytic reduction (SCR) denitration apparatus, and includes, for example, nitrogen oxides (NOx) in the exhaust gas G generated by combustion of a carbon-containing fuel or the like; , promotes the reaction of the reducing agent 8 supplied from the reducing agent supply device 10 to remove the NOx component in the exhaust gas G. In addition, although detailed description of the SCR catalyst 3 is abbreviate|omitted, the SCR catalyst 3 is comprised using, for example, various ceramics, titanium oxide, etc. as a support|carrier.

The reducing agent supply device 10 is a device for spraying the above-described reducing agent 8 into the exhaust gas flow passage 2 . The reducing agent supply device 10 described in the present disclosure is configured to inject ammonia so that the concentration distribution of ammonia becomes uniform in the direction intersecting the flow direction of the exhaust gas G.

Then, the reducing agent supply apparatus 10 which concerns on at least one Embodiment of this invention is demonstrated.

2 is a side cross-sectional view schematically showing the configuration of a reducing agent supply device according to an embodiment. FIG. 3 is a diagram schematically showing the configuration of a reducing agent supply device according to an embodiment, and is a partially enlarged view of part III shown in FIG. 2 .

2 and 3 , the reducing agent supply apparatus 10 according to at least one embodiment of the present invention is an apparatus also referred to as an ammonia injection apparatus or an ammonia injection grid (AIG), and includes At least one header pipe (12) configured to allow ammonia to flow through and extending into the exhaust gas flow path (2) is provided. In addition, the reducing agent supply device 10 is configured to supply the reducing agent 8 upstream of the SCR catalyst 3 in the flow path (exhaust gas flow path 2) of the exhaust gas G on which the obstacle 7 is disposed. A reducing agent supply device (10) for A plurality of injection nozzles 20 and a plurality of reducing agent supply lines 30 configured to supply the reducing agent 8 to the plurality of injection nozzles 20 are provided.

Each of the plurality of injection nozzles 20 is disposed in the header pipe 12 on the downstream side in the flow direction of the exhaust gas G with respect to the header pipe 12, and the reducing agent 8 is directed toward the downstream side. It is formed to spray. For example, the plurality of injection nozzles 20 may be arranged at equal intervals along the extension direction of the header pipe 12 .

And, the plurality of spray nozzles 20 is, among the plurality of spray nozzles 20 , the spray nozzles 20 located downstream of the obstacle 7 , the first spray nozzle 21A and the obstacle 7 . In the case where the injection nozzle 20 not located downstream is defined as the second injection nozzle 22A, comprising at least one injection nozzle 20 configured to supply the reducing agent 8 by the same reducing agent supply line 30 as a plurality of injection nozzle groups 24 to The group 24 is divided into a plurality of spray nozzle groups 24 including a second spray nozzle group 22 .

For example, the first injection nozzle group 21 has a width in the one direction than the projection to the downstream of the obstacle 7 located upstream of the first injection nozzle group 21 in the exhaust gas flow path 2 . It may be arrange|positioned in this wide 1st header pipe segment 12A. In this case, the second injection nozzle 22A may be disposed in the second header pipe segment 12B, which is wider than the first header pipe segment 12A in the one direction. Each header pipe segment 12A, 12B may include an internal flow path for guiding the reducing agent supplied from each reducing agent supply line 30 to each injection nozzle 20 .

The plurality of reducing agent supply lines 30 may branch from a main supply line (not shown) and extend into the exhaust gas flow path 2, and may be configured to supply a reducing agent to the spray nozzle group 24 corresponding to each. have.

According to the reducing agent supply device 10 configured as described above, in the flow path 2 of the exhaust gas G, a plurality of injection nozzles 20 are arranged along one direction intersecting the flow direction of the exhaust gas G. This includes a first injection nozzle group 21 including a first injection nozzle 21A located downstream of the obstacle 7 , and a second injection nozzle 22A not located downstream of the obstacle 7 . is divided into spray nozzle groups 24 , and a reducing agent 8 is supplied to each spray nozzle group 24 through the same reducing agent supply line 30 . Thereby, the injection amount of the reducing agent 8 injected from the 1st injection nozzle group 21 including the 1st injection nozzle 21A located downstream of the obstacle 7 is independent of the 2nd injection nozzle group 22 can be adjusted with Therefore, even if a drift occurs downstream of the obstacle 7 due to the existence of the obstacle 7, if the amount of the reducing agent 8 supplied to the first injection nozzle group 21 is appropriately adjusted, the drift is caused Thus, it is possible to suppress the imbalance of the local concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G, which occurs downstream of the injection nozzle group 24 . That is, it is possible to provide the reducing agent supply device 10 capable of suppressing the imbalance of the local concentration distribution of the reducing agent 8 due to the influence of the drift caused by the obstacle 7 .

In the above configuration, in some embodiments, for example, as illustrated in FIG. 3 , the number of first injection nozzles 21A included in one first injection nozzle group 21 is one second injection. It may be less than the number of the 2nd injection nozzle 22A contained in the nozzle group 22. As shown in FIG.

In this way, the number of the first injection nozzles 21A included in the one first injection nozzle group 21 is smaller than the number of the second injection nozzles 22A included in the one second injection nozzle group 22 . According to [ The influence on the concentration distribution of the local reducing agent 8 by the obstacle 7 (for example, a thin pipe or a strut, etc.) having a small ratio in the flow passage cross-sectional area is more finely suppressed to achieve a uniform concentration distribution. can

In any one of the structures described above, in some embodiments, for example, as illustrated in FIGS. 2 and 3 , the exhaust gas flow path in one direction intersecting the flow direction of the exhaust gas G The width (W) of (2), as the width (D) of the obstacle (7) in the flow direction, the distance (L) between the obstacle (7) and the first injection nozzle group (21) in the flow direction A, the following formula (i) or (ii) may be satisfied.

L ≤ 2W … (i)

L ≤ 20D … (ii)

That is, the distance L of the injection nozzle group 24 including the first injection nozzle group 21 and the second injection nozzle group 22 and the obstacle 7 along the exhaust gas flow path 2 is the exhaust gas It may be approximately twice the width W of the flow path 2 or less, or approximately 20 times or less the width D of the obstacle 7 (for example, when the pipe or the like is the obstacle 7, its outer diameter) may be

Here, at a position sufficiently far downstream from the obstacle 7, the influence of the wake of the obstacle 7 is small, and the concentration distribution of the reducing agent 8 in one direction intersecting with the flow direction of the exhaust gas G is Since it approaches uniformity, the necessity of dividing the injection nozzle group 24 locally falls. On the other hand, at a position where the distance between the obstacle 7 and the spray nozzle group 24 is close and the influence of the wake is significant, the local concentration distribution imbalance can be effectively reduced by dividing the spray nozzle group 24 locally.

In this regard, as described above, the width W of the exhaust gas flow path 2, the width D of the obstacle 7 in the flow direction of the exhaust gas G, and the obstacle in the flow direction ( According to the configuration in which the distance L between 7) and the first injection nozzle group 21 satisfies the above formula (i) or (ii), the influence of the wake of the obstacle 7 is large in the formula (i) or formula By arranging the first injection nozzle group 21 at a position that satisfies the relation of (ii), the effects described in any one of the above-described embodiments can be maximally enjoyed.

In addition, the distance L in the said formula (i) or (ii) is the downstream end of the header pipe 12, ie, the proximal end of the injection nozzle 20, in the flow direction of the exhaust gas G It is good also as a side end, and it is good also considering the downstream end of the injection nozzle 20 as a downstream end. In addition, the downstream end of the obstacle 7 may be applied as the upstream end of the distance L, and the center of the obstacle 7 (for example, the centroid of the obstacle 7 in FIG. 3) may be taken as the upstream end.

In any one of the structures described above, in some embodiments, for example, as illustrated in FIG. 3 , the first injection nozzle group 21 is, for example, in the flow direction or exhaust of the exhaust gas G When the angular range of the drift by the obstacle 7 with respect to the pipe axis of the gas flow path 2 is set to θ, with respect to the width (W) direction of the exhaust gas flow path 2, it is included in the range of D + 2Lsinθ The injection nozzle 20 may be included as 21 A of 1st injection nozzles.

In addition, in some embodiments, for example, the injection nozzle 20 arranged to be shifted in the one direction with respect to the projection in the flow direction of the obstacle 7 located upstream of the first injection nozzle group 21 is eliminated. You may define as 21 A of 1 injection nozzles. For example, the first injection nozzle 21A may be arranged so that the entirety of the first injection nozzle 21A overlaps when viewed from the tube axis direction of the exhaust gas flow passage 2 with respect to the projection of the obstacle 7 toward the downstream side of the exhaust gas flow passage 2 . . Moreover, 21 A of 1st injection nozzles may be arrange|positioned with respect to the projection of the said obstacle 7, and may be arrange|positioned so that at least one part may overlap when viewed from the tube axis direction of the exhaust gas flow path 2 . In addition, 21 A of 1st injection nozzles may be shifted|shifted in the width direction of the exhaust gas flow path 2 so that it may not overlap with the said projection, and may be arrange|positioned.

In addition, the first injection nozzle group 21 is disposed in the width direction of the exhaust gas flow path 2 (one direction intersecting the flow direction of the exhaust gas G) with respect to the projection of the obstacle 7 located upstream. In this case, the injection nozzle 20 positioned closest to the projection may be included as the first injection nozzle 21A. Alternatively, in the first spray nozzle group 21, one or a plurality of spray nozzles 20 included in the range that can be affected by the wake of the obstacle 7 located upstream is used as the first spray nozzle 21A. may be included.

Here, the drift caused by the obstacle 7 may be variously changed depending on the shape of the obstacle 7, the distance L between the obstacle 7 and the injection nozzle 20, or the flow rate of the exhaust gas G, etc. Therefore, in the flow of the exhaust gas G, there is a fear that the uniformity of the concentration distribution cannot be efficiently performed only by adjusting the injection amount from the injection nozzle 20 arranged at a position strictly downstream of the obstacle 7 there is

In this regard, according to the above configuration, with respect to the projection of the obstacle 7 with respect to the flow direction of the exhaust gas G, the first injection nozzle disposed to be shifted in one direction intersecting the flow direction of the exhaust gas G The supply amount of the reducing agent 8 to the first injection nozzle group 21 including 21A can be individually adjusted. Accordingly, according to various arrangements and designs of the obstacles 7 and the like in the exhaust gas flow path 2 , the injection nozzles 20 divided into the first injection nozzle group 21 among the plurality of injection nozzles 20 are selected. Design freedom when making decisions can be improved.

Fig. 4 is a side sectional view schematically showing adjustment of the concentration of the reducing agent by the reducing agent supply device according to the embodiment.

In any one of the structures described above, in some embodiments, for example, as illustrated in FIGS. 2 to 4 , the plurality of injection nozzles 20 span the entire width of the exhaust gas flow path 2 . You may arrange|position them discretely. You may set the space|interval between each injection nozzle 20, the number of the injection nozzles 20 in the width direction of the exhaust gas flow path 2, etc. arbitrarily.

In this way, according to the configuration in which the plurality of injection nozzles 20 are discretely arranged over the entire width of the exhaust gas flow path 2 , the concentration distribution of the reducing agent 8 over the entire width of the exhaust gas flow path 2 is equalization can be achieved. Therefore, for example, when the reducing agent supply device 10 is disposed upstream of the SCR catalyst 3 formed over the entire width of the exhaust gas flow path 2 , the reducing agent in the width direction of the exhaust gas flow path 2 . It is possible to maximize the effect of equalizing the concentration distribution of the SCR catalyst (3), thereby maximizing the denitration performance of the SCR catalyst (3).

In addition, as illustrated in FIG. 4, for example, the some injection nozzle 20 WHEREIN: In the width direction in the exhaust gas flow path 2, the flow velocity of the exhaust gas G may be divided for each different flow velocity region. .

It is a block diagram which shows the structure of the control system in the reducing agent supply apparatus which concerns on one Embodiment.

In any one of the structures described above, in some embodiments, for example, as illustrated in FIGS. 2, 4, and 5 , the reducing agent supply device 10 includes a plurality of injection nozzle groups in the flow direction. a concentration sensor (40) disposed downstream of (24) for measuring a concentration distribution of the reducing agent (8) in the exhaust gas (G) in one direction intersecting the flow direction of the exhaust gas (G); A plurality of flow control valves 32 formed corresponding to each of the plurality of reducing agent supply lines 30 and a plurality of valve actuators 34 capable of independently changing the respective opening degrees of the plurality of flow control valves 32; A controller 50 for driving the valve actuator 34 to equalize the concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G according to the detection signal of the concentration sensor 40 is added may be provided as

The concentration sensor 40 may be configured to measure the concentration distribution of the reducing agent in the width direction of the exhaust gas flow passage 2 , for example.

The controller 50 is, for example, a computer, and includes a CPU 51 and a ROM (Read Only Memory) 53 as a storage unit for storing data such as various programs and tables executed by the CPU 51, each In addition to a RAM (Random Access Memory) 52 functioning as a work area such as a development area for executing a program or a arithmetic area, a hard disk drive (HDD) as a mass storage device (not shown), a communication interface for connecting to a communication network , and an access unit to which an external storage device is mounted may be provided. All of these are connected via the bus 55 . Further, the controller 50 may be connected to, for example, an input unit (not shown) composed of a keyboard, mouse, touch panel, or the like, and a display unit (not shown) composed of a liquid crystal display device for displaying data, or the like.

In some embodiments, in the ROM 53 , for example, in response to a detection signal from the concentration sensor 40 , each valve is configured such that the concentration of the reducing agent in the width direction of the exhaust gas flow path 2 becomes uniform. The actuator 34 is driven to adjust the opening degree of the flow control valve 32 , and the injection amount of the reducing agent injected from the injection nozzles 20 of each of the first injection nozzle group 21 or the second injection nozzle group 22 . A reducing agent injection amount adjustment program 54 for adjusting .

According to the configuration further provided with the concentration sensor 40, the flow rate control valve 32, the valve actuator 34, and the controller 50 in this way, the controller 50 according to the detection signal from the concentration sensor 40 Each of the valve actuators 34 can be feedback-controlled so that the concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G may be equalized. Thereby, for example, the concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G is not required, without requiring an operation for adjusting the opening degree of the individual flow control valve 32 by an operator. can be equalized in real time.

Subsequently, a reducing agent supply method according to at least one embodiment of the present invention will be described.

6 is a flowchart showing a reducing agent supply method according to at least one embodiment of the present invention.

As illustrated in FIG. 6 , in the operating method of the reducing agent supply device 10 according to at least one embodiment of the present invention, the SCR catalyst 3 in the exhaust gas flow path 2 in which the obstacle 7 is disposed. It is an operating method of the reducing agent supply apparatus 10 for supplying the reducing agent 8 upstream.

In this method, the reducing agent supply device 10 is spaced along one direction intersecting with respect to the flow direction of the exhaust gas G, downstream of the obstacle 7 in the flow direction of the exhaust gas G A plurality of injection nozzles 20 arranged so as to be disposed therebetween, and a plurality of reducing agent supply lines 30 configured to supply the reducing agent 8 to the plurality of injection nozzles 20 are provided. Among the plurality of injection nozzles 20 , the first injection nozzle 21A is the injection nozzle 20 located downstream of the obstacle 7 , and the injection nozzle 20 that is not located downstream of the obstacle 7 is the second When defined as the spray nozzle 22A, the plurality of spray nozzles 20 is a plurality of spray nozzles including at least one spray nozzle 20 configured to be supplied with the reducing agent 8 by the same reducing agent supply line 30 . As the nozzle group 24 , a first injection nozzle group 21 which is an injection nozzle group 24 including the first injection nozzle 21A, and a injection nozzle group 24 including the second injection nozzle 22A It is divided into a plurality of injection nozzle groups 24 including the phosphorus second injection nozzle group 22 .

And, in the operating method of the reducing agent supply device 10, downstream of the plurality of injection nozzles 20 in the flow direction of the exhaust gas G, in one direction intersecting the flow direction of the exhaust gas G, measuring the concentration distribution of the reducing agent 8 or NOx (step S10), and the reducing agent supplied to the first injection nozzle group 21 and the second injection nozzle group 22 according to the measurement result of the concentration distribution A step (step S20) of individually adjusting the amount of (8) is provided.

According to this method, in the flow path 2 of the exhaust gas G, a plurality of injection nozzles 20 arranged along one direction intersecting with respect to the flow direction of the exhaust gas G are disposed downstream of the obstacle 7 . a first spray nozzle group 21 including a first spray nozzle 21A positioned at are separated, and the reducing agent 8 is supplied to each injection nozzle group 24 by the same reducing agent supply line 30 . Thereby, the injection amount of the reducing agent 8 injected from the 1st injection nozzle group 21 including the 1st injection nozzle 21A located downstream of the obstacle 7 is independent of the 2nd injection nozzle group 22 can be adjusted with Therefore, even if a drift occurs downstream of the obstacle 7 due to the existence of the obstacle 7, if the amount of the reducing agent 8 supplied to the first injection nozzle group 21 is appropriately adjusted, the drift is caused Thus, it is possible to suppress the imbalance of the local concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G, which occurs downstream of the injection nozzle group 24 . In addition, according to the concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G measured downstream of the plurality of injection nozzles 20, the concentration distribution of the reducing agent 8 is equalized. The quantity of the reducing agent 8 supplied to the 1 injection nozzle group 21 and the 2nd injection nozzle group 22 can be adjusted individually. Thereby, for example, the concentration distribution of the reducing agent 8 in one direction intersecting the flow direction of the exhaust gas G is obtained without requiring an operation for adjusting the opening degree of the individual injection nozzles 20 by an operator. can be equalized.

According to at least one embodiment of the present invention described above, the reducing agent supply device 10 capable of suppressing the imbalance of the local concentration distribution of the reducing agent 8 due to the influence of the drift caused by the obstacle 7 , and the reducing agent supply device (10) can provide an operating method.

This invention is not limited to embodiment mentioned above, The form which added the deformation|transformation to the above-mentioned embodiment, and the form which combined these forms suitably are also included.

1: denitrification device
2: exhaust gas flow path (euro/year)
3: SCR catalyst (denitration catalyst)
4: Boiler
5: Brazier
6: year
7: obstacle
8: reducing agent
10: reducing agent supply device
12: header tube
12A: first header tube segment
12B: second header tube segment
20: spray nozzle
21: first injection nozzle group
21A: first injection nozzle
22: 2nd injection nozzle group
22A: second injection nozzle
24: spray nozzle group
30: reducing agent supply line
32: flow control valve
34: valve actuator
40: concentration sensor
50 : controller
51: CPU
52: RAM
53 : ROM
54: reducing agent injection amount adjustment program
55 : bus
100: boiler system
G: exhaust gas

Claims (6)

A reducing agent supply device for supplying a reducing agent upstream of an SCR catalyst in an exhaust gas flow path having an obstacle disposed therein, comprising:
a plurality of injection nozzles arranged at intervals along one direction intersecting with respect to the flow direction of the exhaust gas downstream of the obstacle in the flow direction of the exhaust gas;
and a plurality of reducing agent supply lines configured to supply the reducing agent to the plurality of spray nozzles,
Among the plurality of injection nozzles, when the injection nozzle located downstream of the obstacle is defined as the first injection nozzle and the injection nozzle not located downstream of the obstacle is defined as the second injection nozzle,
The plurality of injection nozzles are a plurality of injection nozzle groups including at least one injection nozzle configured to supply the reducing agent through the same reducing agent supply line, and the first injection nozzle group including the first injection nozzle The reducing agent supply device, which is divided into a plurality of spray nozzle groups including a nozzle group, and a second spray nozzle group that is the spray nozzle group including the second spray nozzle. The method of claim 1,
The number of the first injection nozzles included in one of the first injection nozzle groups is smaller than the number of the second injection nozzles included in the one second injection nozzle group, the reducing agent supply device. 3. The method of claim 1 or 2,
As the width (W) of the flow path in the one direction and the width (D) of the obstacle in the flow direction, the distance (L) between the obstacle and the first injection nozzle group in the flow direction is , 2 times or less of W, or 20 times or less of D, a reducing agent supply device. 3. The method of claim 1 or 2,
The plurality of injection nozzles are discretely arranged over the entire width of the flow path. 3. The method of claim 1 or 2,
a concentration sensor disposed downstream of the plurality of injection nozzle groups in the flow direction to measure a concentration distribution of the reducing agent or NOx in the exhaust gas in the one direction;
A plurality of flow control valves formed corresponding to each of the plurality of reducing agent supply lines and a plurality of valve actuators capable of independently changing the respective opening degrees of the plurality of flow control valves;
A reducing agent supply device further comprising a controller for driving the valve actuator in accordance with the detection signal of the concentration sensor. A method of operating a reducing agent supply device for supplying a reducing agent upstream of an SCR catalyst in an exhaust gas flow path having an obstacle disposed therein, comprising:
The reducing agent supply device,
a plurality of injection nozzles arranged at intervals along one direction intersecting with respect to the flow direction of the exhaust gas downstream of the obstacle in the flow direction of the exhaust gas;
and a plurality of reducing agent supply lines configured to supply the reducing agent to the plurality of spray nozzles,
Among the plurality of injection nozzles, when the injection nozzle located downstream of the obstacle is defined as the first injection nozzle and the injection nozzle not located downstream of the obstacle is defined as the second injection nozzle,
The plurality of injection nozzles are a plurality of injection nozzle groups including at least one injection nozzle configured to supply the reducing agent through the same reducing agent supply line, and the first injection nozzle group including the first injection nozzle It is divided into a plurality of spray nozzle groups including a nozzle group, and a second spray nozzle group that is the spray nozzle group including the second spray nozzle,
The operating method of the reducing agent supply device,
measuring the concentration distribution of the reducing agent or NOx in the one direction downstream of the plurality of injection nozzles in the flow direction of the exhaust gas;
and individually adjusting the amounts of the reducing agent supplied to the first injection nozzle group and the second injection nozzle group according to a measurement result of the concentration distribution.

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