JP2019074253A - Method for supplying oxygen-containing gas to secondary combustion chamber, and secondary combustion facility - Google Patents

Abstract

To provide a method for supplying oxygen-containing gas to a secondary combustion chamber, capable of reducing concentration of CO contained in exhaust gas discharged from the secondary combustion chamber.SOLUTION: A method for supplying oxygen-containing gas to a secondary combustion chamber (20) comprises an upstream side supply step of supplying oxygen-containing gas to an upstream side space in the secondary combustion chamber (20), and a downstream side supply step of supplying oxygen-containing gas to a downstream side space in the secondary combustion chamber (20). In the upstream side supply step, oxygen-containing gas is supplied to the upstream side space so that a single swirl flow (S) occurs in the upstream side space, wherein the single swirl flow is formed by causing oxygen-containing gas to swirl in a specific direction on an axis orthogonal cross section. In the downstream supply step, oxygen-containing gas is supplied to the downstream side space so that a single swirl flow (S) occurs in the downstream side space, wherein the single swirl flow swirls in the same direction as the swirl direction of the foregoing single swirl flow (S).SELECTED DRAWING: Figure 1

Description

  The present invention relates to the supply of oxygen-containing gas (which is a gas containing oxygen) to a secondary combustion chamber.

  In general, the stoker type incinerator, the gasification and melting furnace, etc. have a secondary combustion chamber for burning the exhaust gas discharged from the primary combustion chamber, and the secondary combustion chamber is an air for burning the exhaust gas. Are often supplied. For example, Patent Document 1 discloses a stoker type incinerator having a furnace main body having a primary combustion chamber and a secondary combustion chamber, and a secondary air nozzle for blowing air into the secondary combustion chamber. The secondary air nozzle has three front wall nozzles provided on the front wall of the secondary combustion chamber and two partition wall nozzles provided on the partition wall facing the front wall of the secondary combustion chamber. doing. Each front wall nozzle is provided at the central portion in the width direction of the front wall (the direction orthogonal to both the direction in which the front wall and the partition wall oppose and the vertical direction), and at different height positions. Supply air towards the Each partition wall nozzle is provided at a widthwise end of the partition wall and at a position lower than the front wall nozzle, and supplies air toward the front wall. For this reason, in the secondary combustion chamber, the air supplied from each front wall nozzle and the air supplied from one of the partition wall nozzles in a half area in a cross section orthogonal to the axial direction of the secondary combustion chamber A first swirling flow is formed in a clockwise direction, and the air supplied from each front wall nozzle and the air supplied from the other partition wall nozzle are left in the remaining half area in the cross section. A second swirling flow is formed which pivots around. In these two swirling flows, in the height direction, the nozzle positioned at the highest of the front wall nozzles from the position at which each partition wall nozzle is provided (the space on the upstream side in the secondary combustion chamber) is provided It is formed in the range which reaches to the position (downstream space in the secondary combustion chamber). Since these two swirling flows promote mixing of the exhaust gas discharged from the primary combustion chamber and the air supplied from the secondary air nozzle, carbon monoxide (CO) contained in the exhaust gas in the secondary combustion chamber And combustible gases such as are effectively burned.

JP, 2009-121747, A

  In the method of supplying air to the secondary combustion chamber as described in Patent Document 1, the concentration of CO contained in the exhaust gas discharged from the secondary combustion chamber may be high.

  An object of the present invention is to provide a method and an apparatus for supplying oxygen-containing gas to a secondary combustion chamber capable of reducing the concentration of CO contained in exhaust gas discharged from the secondary combustion chamber.

  As a result of intensive studies to solve the above problems, in the secondary combustion chamber as described in Patent Document 1, as a result of exhaustive investigation into the secondary combustion chamber as described in Patent Document 1, the exhaust gas flowing into the secondary combustion chamber The secondary combustion chamber may rise as it is unevenly distributed in the region, and in this case, when a plurality of swirling flows are formed in a cross section orthogonal to the axial direction of the secondary combustion chamber, the flow velocity of each swirling flow is small. As a result, the mixing of exhaust gas and air by each swirling flow becomes insufficient, and as a result, combustible gas (CO etc.) that did not react with air in the secondary combustion chamber is discharged from the secondary combustion chamber It has been found that the concentration of CO contained in the exhaust gas is increased by

  Therefore, the inventors of the present invention have made it possible to form an oxygen-containing gas such that a single swirling flow that turns in the same direction in the cross section is formed in both the upstream space and the downstream space in the secondary combustion chamber. By supplying (air or the like) into the secondary combustion chamber, the flow velocity of the single swirling flow is increased as compared with the case where a plurality of swirling flows swirling in different directions are formed in the cross section, It was conceived that it is possible to effectively promote the mixing of the exhaust gas discharged from the primary combustion chamber in the secondary combustion chamber and the oxygen-containing gas.

  The present invention has been made based on the above-mentioned viewpoints. Specifically, the present invention is a method of supplying an oxygen-containing gas, which is a gas containing oxygen, to a cylindrically formed secondary combustion chamber that burns the exhaust gas discharged from the primary combustion chamber. And an upstream supply step of supplying the oxygen-containing gas to the space on the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas, and the space on the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas. A downstream supply step of supplying the oxygen-containing gas to a space on the downstream side of the oxygen-containing gas, in the upstream supply step, the oxygen-containing cross section being an orthogonal cross section which is a cross section orthogonal to a central axis of the secondary combustion chamber The oxygen-containing gas is supplied to the upstream space such that a single swirling flow formed by the gas swirling in a specific direction is generated in the upstream space, and in the downstream supply step, one The oxygen-containing gas supply to the secondary combustion chamber, which supplies the oxygen-containing gas to the downstream space such that a single swirling flow swirling in the same direction as the swirling direction of the swirling flow is generated in the downstream space Provide a way.

  In the method for supplying oxygen-containing gas to the secondary combustion chamber, a single swirl flow swirling in the same direction is formed in the space on the upstream side and the space on the downstream side. The exhaust gas and the oxygen-containing gas are effectively mixed in the secondary combustion chamber as compared with the case where a plurality of swirling flows are formed. Thus, the combustible gas contained in the exhaust gas is effectively burned in the secondary combustion chamber, so that the CO concentration of the exhaust gas discharged from the secondary combustion chamber is reduced.

  In this case, in the upstream supply step, the oxygen-containing gas is preferably supplied to the upstream space so as to generate an air flow toward the central axis of the secondary combustion chamber in the axial orthogonal cross section.

  In this way, it is possible to suppress gas flow from the space on the upstream side to the space on the downstream side in the vicinity of the central portion of the secondary combustion chamber in the axis orthogonal cross section in which the flow velocity is relatively low.

  In this case, in the downstream side supply step, the oxygen-containing gas is supplied from a portion separated 0.9 m to 3 m downstream in the flow direction from the portion supplying the oxygen-containing gas in the upstream side supply step Is preferred.

  In this way, the CO concentration of the exhaust gas discharged from the secondary combustion chamber can be reduced more reliably. Specifically, when the distance between the portion to which the oxygen-containing gas is supplied in the downstream side supply step and the portion to which the oxygen-containing gas is supplied in the upstream side supply step is 0.9 m or more, a single swirling flow is generated. Since inhibition of the formation of the air flow toward the central axis of the secondary combustion chamber is suppressed, a decrease in the reaction rate of CO contained in the exhaust gas is suppressed, and the distance is 3 m or less. Since the temperature of the exhaust gas is maintained to such an extent that the combustion in the secondary combustion chamber of the exhaust gas discharged from the chamber is maintained, the decrease in the combustion rate (the reaction rate of CO) of the exhaust gas is suppressed.

  Further, in the upstream supply step, it is preferable to supply the oxygen-containing gas in a larger amount than the amount of the oxygen-containing gas supplied in the downstream supply step.

  In this manner, the air ratio does not increase compared to the case where the supply amount of the oxygen-containing gas in the upstream supply step is equal to or smaller than the supply amount of the oxygen-containing gas in the downstream supply step. Since the residence time of the oxygen-containing gas in the secondary combustion chamber becomes long, the combustible gas contained in the exhaust gas in the secondary combustion chamber is effectively burned.

  Moreover, in the upstream side supply process and the downstream side supply process, it is preferable to supply the oxygen-containing gas in an amount such that the air ratio is 0.3 or more and 0.5 or less.

  In this way, both cost reduction and reduction of the CO concentration of the exhaust gas discharged from the secondary combustion chamber are achieved.

  In the upstream supply step, the oxygen-containing gas is preferably supplied in an amount of 1 to 1.5 times the supply amount of the oxygen-containing gas in the downstream supply step.

  Further, according to the present invention, there is provided a secondary combustion chamber provided downstream of the primary combustion chamber for burning the exhaust gas discharged from the primary combustion chamber, which is formed in a cylindrical shape, and the secondary combustion chamber A gas supply unit for supplying an oxygen-containing gas, which is a gas containing oxygen, to the oxygen on the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas; An upstream supply unit for supplying a contained gas; a downstream supply unit for supplying the oxygen-containing gas to a space on the downstream side of an upstream space in the secondary combustion chamber with respect to the flow direction of the exhaust gas; , And the upstream supply portion is configured to generate a single swirling flow formed by the oxygen-containing gas swirling in a specific direction in an axial orthogonal cross section that is a cross section orthogonal to the central axis of the secondary combustion chamber. In the upstream space A swirling supply connected to the secondary combustion chamber so that the downstream side is formed by turning in the same direction as the swirling direction of the single swirling flow The secondary combustion facility is connected to the secondary combustion chamber so as to generate a swirl flow in the downstream space.

  In this secondary combustion facility, since a single swirling flow that swirls in the same direction is formed in the upstream space and the downstream space in the secondary combustion chamber, the swirling in mutually different directions is performed in the axis orthogonal cross section. The exhaust gas and the oxygen-containing gas are effectively mixed in the secondary combustion chamber as compared with the case where a plurality of swirling flows are formed. As a result, the combustible gas contained in the exhaust gas burns effectively, so the CO concentration of the exhaust gas discharged from the secondary combustion chamber is reduced.

  In this case, the secondary combustion chamber is connected to the pair of first opposing walls opposing each other in the first direction and the pair of first opposing walls, and is a direction perpendicular to the first direction. A pair of second facing walls facing each other in two directions, wherein the turning supply unit is a first turning supply provided on one of the first facing walls of the pair of first facing walls And a second turning supply portion provided on the other first opposing wall of the pair of first opposing walls, the first turning supply portion having the axis-perpendicular cross section, The first first opposing wall is connected to a portion of the first opposing wall in the second direction that is offset from the center of the first opposing wall in the second direction, and the second turning supply portion has the axis orthogonal cross section In the other first opposing wall in the second direction in the other first opposing wall And the downstream supply portion is provided on a first opposing wall of the one first opposing wall or a second opposing wall of one of the pair of second opposing walls. A downstream side supply unit; and a second downstream side supply unit provided on the other first opposing wall or the other second opposing wall of the pair of second opposing walls; The side supply section is a portion of the one first opposing wall deviated from the center of the one first opposing wall in the second direction to the one side or the one second opposing wall in the axially orthogonal cross section. The second downstream side supply portion is connected to the other first portion in the axis orthogonal cross section in a portion deviated from the center of the one second opposing wall in the first direction to the one side in the first direction. From the center of the other first opposing wall in the second direction among the opposing walls, the other It is preferably connected from the center of the other of the second opposing wall for the first direction of the site or the one of the second opposing wall and biased to the side at a site offset on the other side.

  In this aspect, the single swirling flow is effectively formed in the space on the upstream side by the first swirling feeding portion and the second swirling feeding portion, and the first downstream feeding portion and the second downstream feeding portion Effectively creates the single swirl flow in the downstream space.

  In addition, it is preferable that the upstream supply unit further includes a center supply unit that generates an air flow of the oxygen-containing gas toward the center of the secondary combustion chamber in the axial orthogonal cross section.

  In this way, it is possible to suppress gas flow from the space on the upstream side to the space on the downstream side in the vicinity of the central portion of the secondary combustion chamber in the axis orthogonal cross section in which the flow velocity is relatively low.

  Further, the center supply portion is connected to a portion of the first opposing wall which is deviated in a direction opposite to the swirling direction of the single swirling flow from the center of the first opposing wall in the second direction Is preferred.

  In this way, the oxygen-containing gas supplied from the central supply portion can easily reach the central portion of the secondary combustion chamber under the influence of a single swirl flow. Thus, the mixing of the oxygen-containing gas and the exhaust gas near the center of the secondary combustion chamber is further promoted.

  Specifically, the amount of deviation from the center of the first opposing wall of the center supply portion is set to be larger than 0 and not more than one fourth of the dimension of the first opposing wall in the second direction. Is preferred.

  In this way, the oxygen-containing gas supplied from the central supply portion can more reliably reach the center of the secondary combustion chamber.

  In addition, the downstream supply portion is connected to a portion of the secondary combustion chamber that is separated by 0.9 m or more and 3 m or less downstream in the flow direction from the portion connected to the upstream supply portion. preferable.

  In this way, the CO concentration of the exhaust gas discharged from the secondary combustion chamber can be reduced more reliably. Specifically, a single swirling flow is supplied from the central supply unit because the distance between the portion to which the downstream supply unit is connected and the portion to which the upstream supply unit is connected is 0.9 m or more. Since inhibition of the formation of the air flow (air flow toward the center of the secondary combustion chamber) is suppressed, a decrease in the reaction rate of CO contained in the exhaust gas is suppressed, and the distance is 3 m or less. Since the temperature of the exhaust gas is maintained to such an extent that the combustion in the secondary combustion chamber of the exhaust gas discharged from the primary combustion chamber is maintained, the decrease in the combustion rate of CO (the reaction rate of CO) is suppressed .

  Further, it is preferable that the supply amount of the oxygen-containing gas from the upstream supply unit is set larger than the supply amount of the oxygen-containing gas from the downstream supply unit.

  In this manner, the air ratio does not increase compared to the case where the supply amount of the oxygen-containing gas from the upstream supply unit is equal to or smaller than the supply amount of the oxygen-containing gas from the downstream supply unit. Since the residence time of the oxygen-containing gas in the secondary combustion chamber becomes long, the combustible gas contained in the exhaust gas in the secondary combustion chamber is effectively burned.

  In this case, the upstream supply unit and the downstream supply unit preferably supply the oxygen-containing gas in an amount such that the air ratio is 0.3 or more and 0.5 or less.

  Furthermore, it is preferable that the supply amount of the oxygen-containing gas from the upstream side supply unit is set to 1 to 1.5 times the supply amount of the oxygen-containing gas from the downstream side supply unit.

  As described above, according to the present invention, there is provided a method of supplying oxygen-containing gas to a secondary combustion chamber capable of reducing the concentration of CO contained in exhaust gas discharged from the secondary combustion chamber, and a secondary combustion facility. Is possible.

It is a figure which shows the outline of the melting furnace containing the secondary combustion contact part of one Embodiment of this invention. It is sectional drawing in the II-II line of FIG. It is sectional drawing in the III-III line of FIG. It is a figure which shows the modification of an upstream side supply part.

  The secondary combustion installation 2 of one embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  A melting furnace including a secondary combustion facility 2 is shown in FIG. The melting furnace is provided on the downstream side of a gasification furnace (not shown) for extracting combustible gas from the waste by heating the waste. The melting furnace includes a primary combustion chamber 10 and a secondary combustion facility 2.

  In the primary combustion chamber 10, the combustible gas G1 flowing from the gasification furnace is burned to melt the ash contained in the combustible gas G1. The slag SL formed by melting of the ash content is discharged from the outlet port 10 a provided at the lower part of the primary combustion chamber 10.

  The secondary combustion facility 2 includes a secondary combustion chamber 20 and a gas supply unit 30.

  The secondary combustion chamber 20 is provided downstream of the primary combustion chamber 10. The secondary combustion chamber 20 burns the exhaust gas discharged from the primary combustion chamber 10. The secondary combustion chamber 20 is formed in a square tube shape. In the present embodiment, the secondary combustion chamber 20 is disposed in a posture in which the central axis of the secondary combustion chamber 20 is parallel to the vertical direction. As shown in FIGS. 2 and 3, the secondary combustion chamber 20 includes a pair of first opposing walls 21 opposing each other in the first direction, and a pair of first opposing walls 21 opposing each other in the second direction orthogonal to the first direction. And 2 facing walls 22. A boiler (not shown) that recovers heat from the exhaust gas G2 discharged from the secondary combustion chamber 20 is provided downstream of the secondary combustion chamber 20.

  The gas supply unit 30 is a portion for supplying an oxygen-containing gas (air in the present embodiment) which is a gas containing oxygen to the secondary combustion chamber 20. In the present embodiment, the gas supply unit 30 has a nozzle connected to the secondary combustion chamber 20. Each nozzle is connected to a supply source (not shown) of the oxygen-containing gas through a flow path for supplying the oxygen-containing gas to the nozzle. The gas supply unit 30 has an upstream side supply unit 40 and a downstream side supply unit 50.

  The upstream supply unit 40 is for supplying an oxygen-containing gas to the space Su on the upstream side (lower side in FIG. 1) in the secondary combustion chamber 20 in the flow direction of the exhaust gas (upward in this embodiment). It is. As shown in FIG. 2, the upstream supply unit 40 includes a turning supply unit 42 and a center supply unit 44.

  In the swirling supply section 42, the oxygen-containing gas swirls in a specific direction (clockwise in FIG. 2) in an axial orthogonal cross section (cross section shown in FIG. 2) which is a cross section orthogonal to the central axis C of the secondary combustion chamber 20. To generate a single swirling flow S formed in the upstream space Su. Specifically, the turning supply portion 42 includes a first turning supply portion 42 a provided on one of the pair of first opposing walls 21 and 21, and the pair of first opposing walls 21. , 21 and a second turning supply portion 42 b provided on the other first opposing wall 21.

  The first turning supply portion 42a is located on one side (upper side in FIG. 2) from the center O of the first opposing wall 21 in the second direction of the first opposing wall 21 in the axis orthogonal cross section. Connected to the biased site. The first turning supply portion 42 a is connected to the first opposing wall 21 in a posture orthogonal to the one first opposing wall 21. In the present embodiment, the first turning supply portion 42a has two nozzles.

  The second turning supply portion 42b is the other side (lower side in FIG. 2) from the center O of the other first opposing wall 21 in the second direction of the other first opposing wall 21 in the axis orthogonal cross section. Connected to the biased site. In the present embodiment, the second turning supply portion 42 b is point-symmetrical to the first turning supply portion 42 a with respect to the central axis C of the secondary combustion chamber 20 in the axis orthogonal cross section. It is connected to the opposing wall 21. Therefore, the single swirl flow S is formed in the space Su on the upstream side by supplying the oxygen-containing gas from the first swirling supply portion 42a and the second swirling supply portion 42b.

  The center supply unit 44 is for generating an oxygen-containing gas flow toward the central axis C of the secondary combustion chamber 20 in the axial orthogonal cross section. The central supply unit 44 includes a first central supply unit 44 a provided on the one first opposing wall 21 and a second central supply unit 44 a provided on the other first opposing wall 21. Have.

  From the center O of the first opposing wall 21 with respect to the second direction of the one first opposing wall 21, the first center supply portion 44 a has a direction opposite to the swirling direction of the single swirling flow S (in FIG. It is connected to the part biased downward). The amount of deviation from the center O of the portion where the first center supply portion 44a is provided is set to be larger than 0 and not more than a quarter of the dimension of the first opposing wall 21 in the second direction. There is. The first center supply portion 44 a is connected to the first opposing wall 21 in a posture orthogonal to the one first opposing wall 21. In the present embodiment, the first center supply unit 44a has one nozzle.

  The second center supply portion 44b is connected to the other first opposing wall 21 so as to be point-symmetrical to the first center supply portion 44a on the basis of the central axis C of the secondary combustion chamber 20 in the axis orthogonal cross section. ing. For this reason, when the oxygen-containing gas is supplied from the first center supply unit 44a and the second center supply unit 44b, an air flow toward the central axis C of the secondary combustion chamber 20 is generated in the axial orthogonal cross section.

  The downstream side supply unit 50 is for supplying the oxygen-containing gas to the space Sd on the downstream side (upper side in FIG. 1) of the space Su on the upstream side in the secondary combustion chamber 20 in the flow direction of the exhaust gas. . The downstream side supply unit 50 is formed by turning in the same direction (in the present embodiment, clockwise) as the turning direction of the single turning flow S formed by the oxygen-containing gas supplied from the turning supply unit 42. It is connected to the secondary combustion chamber 20 in a posture in which the single swirling flow S is generated in the downstream space Sd. It is preferable that the downstream side supply part 50 is connected to the site | part which spaced apart 0.9 m or more and 3 m or less downstream from the site | part to which the upstream side supply part 40 was connected among the secondary combustion chambers 20. FIG. In other words, it is preferable that the distance between the part to which the downstream side supply unit 50 is connected and the part to which the upstream side supply unit 40 is connected be set to 0.9 m or more and 3 m or less. As shown in FIG. 3, the downstream side supply unit 50 includes a first downstream side supply unit 52 a and a second downstream side supply unit 52 b.

  The first downstream-side supply unit 52 a is connected to one of the pair of first opposing walls 21 and the first opposing wall 21. More specifically, the first downstream-side supply unit 52a has one side from the center O of the one first opposing wall 21 in the second direction of the one first opposing wall 21 in the axis orthogonal cross section. It is connected to a portion biased to (in FIG. 3, the upper side). The first downstream side supply portion 52 a is connected to the one first opposing wall 21 in a posture orthogonal to the one first opposing wall 21. In the present embodiment, the first downstream side supply unit 52a has two nozzles.

  The second downstream side supply unit 52 b is connected to the other first opposing wall 21 of the pair of first opposing walls 21, 21. More specifically, the second downstream-side supply unit 52a is located on the other side of the other first opposing wall 21 with respect to the center O of the other first opposing wall 21 in the second direction in the axis orthogonal cross section. It is connected to a portion biased to (in FIG. 3, the lower side). In the present embodiment, the second downstream supply unit 52 b is point-symmetrical to the first downstream supply unit 52 a with respect to the central axis C of the secondary combustion chamber 20 in the axis orthogonal cross section. It is connected to the opposing wall 21. For this reason, when the oxygen-containing gas is supplied from the first downstream side supply unit 52a and the second downstream side supply unit 52b, the single swirling flow S is formed in the space Sd on the downstream side.

  In the present embodiment, the supply amount of the oxygen-containing gas from the upstream side supply unit 40 is set to 1 or more and 1.5 or less times the supply amount of the oxygen-containing gas from the downstream side supply unit 50. Further, from the upstream side supply unit 40 and the downstream side supply unit 50, the oxygen-containing gas is supplied in such an amount that the air ratio becomes 0.3 or more and 0.5 or less.

  Next, the operation of the melting furnace of the present embodiment will be described.

  When the melting furnace is operated, the combustible gas G1 discharged from the gasification furnace is burned in the primary combustion chamber 10, whereby the ash contained in the combustible gas G1 is melted. Slag SL formed by melting of the ash content is discharged from the outlet 10a.

  Then, the exhaust gas discharged from the primary combustion chamber 10 flows into the secondary combustion chamber 20. An oxygen-containing gas (air in this embodiment) is supplied from the gas supply unit 30 to the secondary combustion chamber 20. Specifically, the oxygen-containing gas is supplied through the upstream supply unit 40. This corresponds to the upstream side supply process. More specifically, in the upstream supply step, the oxygen-containing gas is supplied through the swirling supply unit 42 and the oxygen-containing gas is supplied through the central supply unit 44. Due to the supply of the oxygen-containing gas through the swirling supply portion 42, a single swirling flow S swirling in a specific direction in the cross section orthogonal to the axis is formed in the space Su upstream of the secondary combustion chamber 20. Further, by the supply of the oxygen-containing gas through the center supply unit 44, a flow of the oxygen-containing gas toward the central axis C of the secondary combustion chamber 20 in the axial orthogonal cross section is formed.

  In addition to the supply of the oxygen-containing gas from the upstream supply unit 40, the oxygen-containing gas is supplied through the downstream supply unit 50. This corresponds to the downstream side supply process. From this supply, in the space Sd on the downstream side of the secondary combustion chamber 20, a single swirling flow S formed in the space Su on the upstream side and a single swirling flow S swirling in the same direction in the axis orthogonal cross section Is formed.

  As described above, in the method for supplying oxygen-containing gas to the secondary combustion chamber 20 of the present embodiment, a single unit swirls in the same direction in the axial orthogonal section to the space Su on the upstream side and the space Sd on the downstream side. Since the swirling flow S is formed, the exhaust gas and the oxygen-containing gas are more effective in the secondary combustion chamber 20 than in the case where a plurality of swirling flows swirling in different directions are formed in the axis orthogonal cross section. Mix. Thereby, the combustible gas contained in the exhaust gas is effectively burned in the secondary combustion chamber 20, so the CO concentration of the exhaust gas G2 discharged from the secondary combustion chamber 20 is reduced.

  Further, in the upstream supply step, the oxygen-containing gas is supplied to the space Su on the upstream side so as to generate an air flow toward the central axis C of the secondary combustion chamber 20 in the axially orthogonal cross section, so that the flow velocity is relatively high. In the vicinity of the central portion of the secondary combustion chamber 20 in the axially orthogonal cross section, which is smaller, it is possible to suppress the gas flow blown from the space Su on the upstream side to the space Sd on the downstream side.

  Further, in the upstream side supply step, since a larger amount of oxygen-containing gas is supplied than the amount of the oxygen-containing gas supplied in the downstream side supply step, the supply amount of the oxygen-containing gas in the upstream side supply step is the downstream side supply. The residence time of the oxygen-containing gas in the secondary combustion chamber 20 is increased without increasing the air ratio, as compared with the case where the supply amount of the oxygen-containing gas in the process is the same or smaller. Therefore, the combustible gas contained in the exhaust gas in the secondary combustion chamber 20 burns effectively.

  Further, in the downstream side supply step, the oxygen-containing gas is supplied from a portion separated by 0.9 m or more and 3 m or less downstream in the flow direction from the portion supplying the oxygen-containing gas in the upstream side supply step. The CO concentration of the exhaust gas G2 discharged from the exhaust gas is more reliably reduced. Specifically, by securing a distance of 0.9 m or more between the portion to which the downstream side supply portion 50 is connected and the portion to which the upstream side supply portion 40 is connected, a single swirling flow S is supplied to the center Since inhibition of the formation of the air flow (air flow toward the center of the secondary combustion chamber 20) supplied from 44 is suppressed, the decrease in the reaction rate of CO contained in the exhaust gas G2 is suppressed. Further, by setting the distance to 3 m or less, the temperature of the exhaust gas is secured to the extent that the combustion in the secondary combustion chamber 20 of the exhaust gas discharged from the primary combustion chamber 10 is maintained (for example, at 850 ° C. or higher) As a result, it is possible to suppress the decrease in the combustion rate (CO reaction rate) of the exhaust gas.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the description of the embodiments described above but by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

  For example, the first downstream supply unit 52a is connected to one of the second opposing walls 22 and 22, and the second downstream supply unit 52b is connected to the second opposing walls 22. , 22 may be connected to the other second opposing wall 22.

  Further, the number of the nozzles of the upstream side supply unit 40 and the downstream side supply unit 50 is not limited to the above example. Further, the number of nozzles of the downstream side supply unit 50 may be the same as the number of nozzles of the upstream side supply unit 40.

  Further, as shown in FIG. 4, the center supply portion 44 may be provided at a position including the center O of the first opposing wall 21. Not only the upstream supply unit 40 but also the downstream supply unit 50 may have a central supply unit.

  The gas supply unit 30 may further include an intermediate supply unit provided between the upstream side supply unit 40 and the downstream side supply unit 50. The intermediate supply unit is preferably connected to the secondary combustion chamber 20 in a posture to generate an oxygen-containing gas flow toward the central axis C of the secondary combustion chamber 20 in the axial orthogonal cross section. Thereby, from the central portion of the space Su on the upstream side in the axially orthogonal cross section, without substantially inhibiting the formation of the single swirling flow S in the space Su on the upstream side and the space Sd on the downstream side. Blow-through of the gas to the central portion of the downstream space Sd or to the downstream side thereof is more reliably suppressed.

  In addition, each nozzle of the gas supply unit 30 may be connected to the opposing wall in a posture in which the central axis of the nozzle intersects the opposing wall.

  Further, the secondary combustion chamber 20 may be disposed in a posture in which the central axis of the secondary combustion chamber 20 intersects with the vertical direction.

2 secondary combustion equipment 10 primary combustion chamber 20 secondary combustion chamber 21 first opposing wall 22 second opposing wall 30 gas supply unit 40 upstream side supply unit 42 turning supply unit 42a first turning supply unit 42b for second turning Supply unit 44 Central supply unit 44a First central supply unit 44b Second central supply unit 50 Downstream side supply unit 52a First downstream side supply unit 52b Second downstream side supply unit S Single swirl flow Su upstream side Space Sd downstream space

The present invention has been made based on the above-mentioned viewpoints. Specifically, the present invention is a method of supplying an oxygen-containing gas, which is a gas containing oxygen, to a cylindrically formed secondary combustion chamber that burns the exhaust gas discharged from the primary combustion chamber. And an upstream supply step of supplying the oxygen-containing gas to the space on the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas, and the space on the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas. A downstream supply step of supplying the oxygen-containing gas to a space on the downstream side of the oxygen-containing gas, in the upstream supply step, the oxygen-containing cross section being an orthogonal cross section which is a cross section orthogonal to a central axis of the secondary combustion chamber The oxygen-containing gas is supplied to the upstream space such that a single swirling flow formed by the gas swirling in a specific direction is generated in the upstream space, and in the downstream supply step, one Single swirling flow swirling in the same direction as the turning direction of the swirling flow is supplied to the oxygen-containing gas to the downstream side of the space, as occurs in the space of the downstream, in the upstream supply step, the downstream supplying a large amount of the oxygen-containing gas than the amount of the oxygen-containing gas supplied by the supplying step, to provide an oxygen-containing gas supply method to the secondary combustion chamber.

In the method for supplying oxygen-containing gas to the secondary combustion chamber, a single swirl flow swirling in the same direction is formed in the space on the upstream side and the space on the downstream side. The exhaust gas and the oxygen-containing gas are effectively mixed in the secondary combustion chamber as compared with the case where a plurality of swirling flows are formed. Thus, the combustible gas contained in the exhaust gas is effectively burned in the secondary combustion chamber, so that the CO concentration of the exhaust gas discharged from the secondary combustion chamber is reduced. Further, the air ratio does not increase as compared with the case where the supply amount of the oxygen-containing gas in the upstream supply step is equal to or smaller than the supply amount of the oxygen-containing gas in the downstream supply step. Since the residence time of the oxygen-containing gas is increased, the combustible gas contained in the exhaust gas in the secondary combustion chamber is effectively burned.

The present invention is also a method of supplying an oxygen-containing gas, which is a gas containing oxygen, to a secondary combustion chamber that burns the exhaust gas discharged from the primary combustion chamber and is formed into a tubular shape. An upstream supply step of supplying the oxygen-containing gas to an upstream space of the secondary combustion chamber with respect to the flow direction of the exhaust gas; and a downstream space of the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas A downstream side supply step of supplying the oxygen-containing gas to the side space, and in the upstream side supply step, the oxygen-containing gas is a cross section orthogonal to the central axis of the secondary combustion chamber; The oxygen-containing gas is supplied to the upstream space such that a single swirling flow formed by swirling in a specific direction is generated in the upstream space, and in the downstream supply process, the single gas flow is performed. Whirl Supplying the oxygen-containing gas to the space of the downstream produce a single swirling flow swirling in the same direction as the turning direction in the space of the downstream side of the flow, the upstream supply step and the downstream supplying step The present invention provides a method of supplying an oxygen-containing gas to a secondary combustion chamber, which supplies the oxygen-containing gas in an amount such that the air ratio is 0.3 or more and 0.5 or less.

Further, according to the present invention, there is provided a secondary combustion chamber provided downstream of the primary combustion chamber for burning the exhaust gas discharged from the primary combustion chamber, which is formed in a cylindrical shape, and the secondary combustion chamber A gas supply unit for supplying an oxygen-containing gas, which is a gas containing oxygen, to the oxygen on the upstream side of the secondary combustion chamber with respect to the flow direction of the exhaust gas; An upstream supply unit for supplying a contained gas; a downstream supply unit for supplying the oxygen-containing gas to a space on the downstream side of an upstream space in the secondary combustion chamber with respect to the flow direction of the exhaust gas; , And the upstream supply portion is configured to generate a single swirling flow formed by the oxygen-containing gas swirling in a specific direction in an axial orthogonal cross section that is a cross section orthogonal to the central axis of the secondary combustion chamber. In the upstream space A swirling supply connected to the secondary combustion chamber so that the downstream side is formed by turning in the same direction as the swirling direction of the single swirling flow Is connected to the secondary combustion chamber so as to generate a swirling flow in the downstream space, and the supply amount of the oxygen-containing gas from the upstream supply unit is the oxygen from the downstream supply unit. To provide a secondary combustion facility which is set larger than the supply amount of the contained gas .

In this secondary combustion facility, since a single swirling flow that swirls in the same direction is formed in the upstream space and the downstream space in the secondary combustion chamber, the swirling in mutually different directions is performed in the axis orthogonal cross section. The exhaust gas and the oxygen-containing gas are effectively mixed in the secondary combustion chamber as compared with the case where a plurality of swirling flows are formed. As a result, the combustible gas contained in the exhaust gas burns effectively, so the CO concentration of the exhaust gas discharged from the secondary combustion chamber is reduced. In addition, the air ratio does not increase as compared with the case where the supply amount of the oxygen-containing gas from the upstream supply portion is equal to or smaller than the supply amount of the oxygen-containing gas from the downstream supply portion. Since the residence time of the oxygen-containing gas is increased, the combustible gas contained in the exhaust gas in the secondary combustion chamber is effectively burned.

Claims (15)

A method of supplying an oxygen-containing gas, which is a gas containing oxygen, to a cylindrically formed secondary combustion chamber that burns an exhaust gas discharged from a primary combustion chamber, comprising:
An upstream supply step of supplying the oxygen-containing gas to an upstream space of the secondary combustion chamber in the flow direction of the exhaust gas;
Providing a downstream supply step of supplying the oxygen-containing gas to a space on the downstream side of the space on the upstream side of the secondary combustion chamber in the flow direction of the exhaust gas;
In the upstream supply step, a single swirling flow formed by the oxygen-containing gas swirling in a specific direction in an axial cross section which is a cross section orthogonal to the central axis of the secondary combustion chamber is the upstream side. Supplying the oxygen-containing gas to the upstream space so as to occur in the space;
In the downstream side supply step, the oxygen-containing gas is supplied to the downstream space such that a single swirl flow swirling in the same direction as the swirl direction of the single swirl flow is generated in the downstream space. , A method of supplying oxygen-containing gas to the secondary combustion chamber. In the method for supplying oxygen-containing gas to the secondary combustion chamber according to claim 1,
In the upstream supply step, oxygen to the secondary combustion chamber is supplied to the space on the upstream side so as to also generate an air flow toward the central axis of the secondary combustion chamber in the axially orthogonal cross section. Containing gas supply method. In the method for supplying oxygen-containing gas to the secondary combustion chamber according to claim 2,
In the downstream side supply step, secondary combustion is performed to supply the oxygen-containing gas from a portion separated by 0.9 m to 3 m downstream in the flow direction from the portion supplying the oxygen-containing gas in the upstream side supply step Method of supplying oxygen-containing gas to the chamber. In the method for supplying oxygen-containing gas to the secondary combustion chamber according to any one of claims 1 to 3,
The method for supplying oxygen-containing gas to a secondary combustion chamber, in the upstream-side supply step, supplying a larger amount of the oxygen-containing gas than the amount of the oxygen-containing gas supplied in the downstream-side supply step. In the method for supplying oxygen-containing gas to a secondary combustion chamber according to any one of claims 1 to 4,
A method for supplying oxygen-containing gas to a secondary combustion chamber, which supplies the oxygen-containing gas in an amount such that an air ratio is 0.3 or more and 0.5 or less in the upstream side supply step and the downstream side supply step. In the method for supplying oxygen-containing gas to the secondary combustion chamber according to claim 5,
In the upstream supply step, the oxygen-containing gas to the secondary combustion chamber is supplied in an amount of 1 to 1.5 times the supply amount of the oxygen-containing gas in the downstream supply step. Supply method. A secondary combustion chamber provided downstream of the primary combustion chamber for burning the exhaust gas discharged from the primary combustion chamber and formed in a tubular shape;
A gas supply unit for supplying an oxygen-containing gas, which is a gas containing oxygen, to the secondary combustion chamber;
The gas supply unit
An upstream supply unit for supplying the oxygen-containing gas to an upstream space of the secondary combustion chamber in the flow direction of the exhaust gas;
A downstream supply unit for supplying the oxygen-containing gas to a space downstream of an upstream space of the secondary combustion chamber with respect to the flow direction of the exhaust gas;
The upstream supply unit is configured to generate a single swirl flow, which is formed by the oxygen-containing gas swirling in a specific direction in an axial cross section that is a cross section orthogonal to the central axis of the secondary combustion chamber, on the upstream side. Having a swirling supply connected to the secondary combustion chamber so as to occur in space,
The downstream supply unit is connected to the secondary combustion chamber so as to generate a single swirl flow, which is formed by swirling in the same direction as the swirling direction of the single swirl flow, in the downstream space. Has been a secondary combustion equipment. In the secondary combustion facility according to claim 7,
The secondary combustion chamber is
A pair of first opposing walls facing each other in a first direction;
A pair of second opposing walls connected to the pair of first opposing walls and opposing each other in a second direction which is a direction orthogonal to the first direction,
The turning supply unit is
A first turning supply portion provided on one of the pair of first opposing walls;
And a second turning supply portion provided on the other first opposing wall of the pair of first opposing walls,
The first turning supply portion is connected to a portion of the one first opposing wall deviated from the center of the one first opposing wall in the second direction to one side in the axis orthogonal cross section. Yes,
The second turning supply portion is connected to a portion of the other first opposing wall deviated from the center of the other first opposing wall in the second direction to the other side in the axis orthogonal cross section. Yes,
The downstream supply unit is
A first downstream side supply portion provided on one second opposing wall of the one first opposing wall or the pair of second opposing walls;
A second downstream side supply portion provided on the other of the other first opposing wall or the other of the pair of second opposing walls;
The first downstream side supply portion is a portion or one of the one first opposing walls deviated from the center of the one first opposing wall in the second direction to the one side in the axis orthogonal cross section. It is connected to a portion of the second opposing wall which is deviated from the center of the one second opposing wall in the first direction to one side,
The second downstream side supply portion is a portion or one of the other first opposing walls deviated from the center of the other first opposing wall in the second direction to the other side in the axis orthogonal cross section. A secondary combustion facility connected to a portion of the second facing wall that is offset from the center of the other second facing wall in the first direction to the other side. In the secondary combustion facility according to claim 8,
The secondary combustion facility, wherein the upstream supply unit further includes a central supply unit for generating a flow of the oxygen-containing gas toward the central axis of the secondary combustion chamber in the axially orthogonal cross section. In the secondary combustion facility according to claim 9,
The center supply portion is connected to a portion of the first opposing wall that is deviated from the center of the first opposing wall in the second direction in the direction opposite to the swirling direction of the single swirling flow. Secondary combustion equipment. In the secondary combustion facility according to claim 10,
The amount of deviation from the center of the first opposing wall of the center supply portion is set to be larger than 0 and not more than one fourth of the dimension of the first opposing wall in the second direction. Next combustion equipment. The secondary combustion facility according to any one of claims 9 to 11,
The downstream side supply part is connected to a part of the secondary combustion chamber separated by 0.9 m or more and 3 m or less downstream in the flow direction from the part connected with the upstream supply part. Facility. The secondary combustion facility according to any one of claims 7 to 12,
The secondary combustion equipment, wherein the supply amount of the oxygen-containing gas from the upstream supply unit is set larger than the supply amount of the oxygen-containing gas from the downstream supply unit. In the secondary combustion facility according to claim 13,
The secondary combustion equipment, wherein the upstream supply unit and the downstream supply unit supply the oxygen-containing gas in an amount such that the air ratio is 0.3 or more and 0.5 or less. In the secondary combustion facility according to claim 14,
The secondary combustion equipment, wherein the amount of supply of the oxygen-containing gas from the upstream side supply unit is set to 1 to 1.5 times the amount of supply of the oxygen-containing gas from the downstream side supply unit.

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