JP2023148385A - Combustion facility and control device - Google Patents

Abstract

To provide a combustion facility that can extend an exhaust gas retention time in a furnace body, and to provide a control device.SOLUTION: A combustion facility includes: a furnace body for transporting an object to be burnt while burning the object therein; and a nozzle for supplying part of an exhaust gas discharged from the furnace body into the furnace body. The nozzle is disposed in a furnace tail of the furnace body in a direction in which an exhaust gas supplied into the furnace body forms a wall jet along a ceiling part of the furnace body.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to combustion equipment and control devices.

For example, in Patent Document 1, in the primary combustion chamber, the secondary air supply nozzle is arranged at a position facing the garbage feeding direction, and the nozzle of the secondary air supply nozzle is arranged along the upper surface of the garbage on the grate. A waste incinerator is disclosed that is oriented to emit secondary air. As the secondary air as a free jet is ejected along the upper surface of the waste, combustion gas is mixed and stirred at the base of the flame, thereby increasing the effect of promoting combustion. This suppresses the occurrence of incomplete combustion, thereby suppressing the generation of unburned matter. On the other hand, in the technique described in Patent Document 1, the gas in the primary combustion chamber is swept away by the secondary air, so the residence time of the gas in the primary combustion chamber may be reduced.

For example, in Patent Document 2, exhaust gas discharged from an incinerator is made into a free jet, and a ceiling wall of a furnace located above a drying grate among a plurality of grate provided at the bottom of an incinerator is disclosed. , and a combustion operation of the combustion furnace in which the gas generated by combustion is supplied from the rear wall of the furnace on the downstream side with respect to the direction of garbage supply in the furnace so as not to directly hit the grate at the bottom of the furnace and to draw gas generated by combustion. A method is disclosed. By supplying recirculated exhaust gas into the furnace, the entire primary combustion chamber inside the furnace is used as a combustion space, reducing nitrogen oxides at the furnace outlet. In the technique described in Patent Document 2, the supply angle of the recirculated exhaust gas is set so that the recirculated exhaust gas is not attenuated due to the influence of the ceiling wall.

For example, in Patent Document 3, in the primary combustion chamber of a combustion furnace, unburned gas generated in the combustion stage is drawn toward the rear wall side by a gas flow as a free jet supplied from a rear supply nozzle, and the unburned gas is supplied to the front part. An incinerator is disclosed in which unburned gas generated in a drying stage is drawn forward by a gas flow as a free jet supplied from a nozzle, and then flows into a secondary combustion chamber. These nozzles contribute to thermal _NOx reduction similar to the conventional one in which recirculated exhaust gas is supplied from the front ceiling wall of the primary combustion chamber.

Furthermore, for example, Patent Document 4 discloses that the central axis of the furnace that discharges exhaust gas generated in the processing space (inside the furnace main body) is biased to a position different from that of the combustion stage, and the first gas port is located in the direction of displacement of the furnace. A stoker furnace is disclosed in which exhaust gas is ejected as a free jet into a processing space from the opposite side. As a result, a secondary flow is formed in the processing space in a direction opposite to the direction of displacement of the furnace, so that the flame grows in a direction away from the furnace. The heat of this flame promotes the drying of the material to be incinerated in the drying stage or the after-combustion in the post-combustion stage, resulting in a reduction in _NOx and unburned gas.

Furthermore, for example, Patent Document 5 describes a stoker-type incinerator equipped with a nozzle that sends at least one of a portion of combustion air and a portion of combustion gas into the furnace as a free jet mixed gas. is disclosed. The nozzle is provided so that the mixing gas can be directed to the top of the flame formed by combustion of the material to be incinerated on the stoker. It is said that this allows the mixing gas ejected from the nozzle to reach the top of the flame or a position above the top of the flame. As a result, the mixing ratio of the mixing gas to the combustion gas can be increased, and the combustion efficiency of unburned components contained in the combustion gas can be increased.

Patent No. 2662746 Patent No. 6116545 International Publication No. 2020/189394 International Publication No. 2021/106645 International Publication No. 2020/071142

In the field of combustion equipment for incinerating waste, there is a need for technology that increases the residence time of exhaust gas within the furnace body.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a combustion facility and a control device that can increase the residence time of exhaust gas within the furnace body.

In order to solve the above problems, the combustion equipment according to the present disclosure includes a furnace body that transports the material to be incinerated while burning it inside, and a part of the exhaust gas discharged from the furnace body that is supplied to the inside of the furnace body. and a nozzle, the nozzle being disposed at the bottom of the furnace body in such a direction that the exhaust gas supplied into the furnace body forms a wall jet along the ceiling of the furnace body.

The control device according to the present disclosure is a control device for the above-mentioned combustion equipment, wherein the combustion equipment further includes a fan that supplies a part of the exhaust gas to the nozzle through an exhaust gas recirculation line, and the CO concentration in the exhaust gas is and a detection unit that detects NO _X concentration, and increases or decreases the rotation speed of the fan when one or more of the CO concentration and _NO It has an adjustment section.

According to the present disclosure, it is possible to provide combustion equipment and a control device that can increase the residence time of exhaust gas within the furnace body.

1 is a diagram showing the configuration of a combustion facility according to an embodiment of the present disclosure. FIG. 1 is an enlarged view of main parts of a combustion facility according to an embodiment of the present disclosure. FIG. 1 is a diagram showing the configuration of a nozzle according to an embodiment of the present disclosure. FIG. 2 is a functional block diagram of a control device according to an embodiment of the present disclosure. 3 is a flowchart illustrating an example of the operation of the control device according to the embodiment of the present disclosure. 3 is a flowchart illustrating an example of the operation of the control device according to the embodiment of the present disclosure. FIG. 1 is a hardware configuration diagram showing the configuration of a computer according to an embodiment of the present disclosure.

Hereinafter, embodiments for implementing a combustion facility according to the present disclosure will be described with reference to the accompanying drawings.

(Combustion equipment)
The combustion equipment is, for example, a stoker-type combustion furnace that incinerates municipal waste, industrial waste, biomass, or the like as incineration materials. Hereinafter, for convenience of explanation, "materials to be incinerated" will be referred to as "garbage." The waste is the fuel for generating the combustion reaction in the combustion furnace.

As shown in FIG. 1, the combustion equipment 100 includes a combustion furnace 1, an exhaust heat recovery boiler 12, a cooling tower 13, a dust collector 14, an outlet passage 15, a chimney 16, and an induction fan 17. , a garbage pit 18, an ash extrusion device 19, an ash pit 20, an exhaust gas recirculation system 21, an exhaust gas concentration acquisition section 25, and a control device 30.

(combustion furnace)
The combustion furnace 1 is a furnace that burns waste W while transporting it inside. As the waste W is burned in the combustion furnace 1, exhaust gas is generated from the combustion furnace 1. The generated exhaust gas is sent to an exhaust heat recovery boiler 12 connected to the upper part of the combustion furnace 1.

The exhaust heat recovery boiler 12 heats water and generates steam by exchanging heat between exhaust gas and water. The generated steam is used, for example, in equipment (not shown) such as a steam turbine outside the combustion equipment 100. The exhaust gas that has passed through the exhaust heat recovery boiler 12 is cooled in a cooling tower 13 and then sent to a dust collector 14 . The exhaust gas from which soot and dust have been removed by the dust collector 14 is discharged into the atmosphere through the outlet passage 15 and the chimney 16.

Here, an induced draft fan 17 (IDF) that can draw exhaust gas generated in the combustion furnace 1 toward the chimney 16 is arranged in the middle of the outlet flow path 15 . The induction fan 17 maintains the inside of the combustion furnace 1 in a negative pressure state by attracting exhaust gas from inside the combustion furnace 1 .

The combustion furnace 1 includes a furnace body 2, a fuel supply mechanism 3, a stoker 4, a wind box 5, a discharge chute 6, a furnace 7, a forced blower 8, a primary air line 9, and an air preheater 10. and a secondary air line 11.

(furnace body)
The furnace body 2 is composed of a plurality of partition walls. A processing space V is defined inside the furnace body 2 for transporting the waste W while burning it. In the processing space V, the waste W is transported in the transport direction Da (the left-right direction in FIGS. 1 and 2) while being burned. The waste W incinerated in the processing space V is discharged to the outside of the furnace body 2 through the discharge chute 6.

Hereinafter, for convenience of explanation, the side from the discharge chute 6 toward the fuel supply mechanism 3 in the transport direction Da (the left side in FIGS. 1 and 2) will be referred to as "one side Dal." Further, the side opposite to the one side Dal where the waste W is transported (the right side in FIGS. 1 and 2) is referred to as "the other side Dar."
The configuration of the furnace body 2 will be described later.

(Fuel supply mechanism)
The fuel supply mechanism 3 is a mechanism that receives waste W from outside the combustion furnace 1 and supplies the received waste W to the processing space V inside the furnace body 2. The fuel supply mechanism 3 in this embodiment includes a hopper 300 and a feeder 310.

The hopper 300 is an inlet of the combustion furnace 1 for supplying waste W into the inside of the furnace body 2. Garbage W is thrown into the hopper 300 from outside the combustion furnace 1 by the crane 182. Hopper 300 has an inlet section 301 and an outlet section 302.

The inlet portion 301 is an inlet portion of the hopper 300 into which waste W enters from the outside. The inlet section 301 guides the waste W supplied from the upper side in the vertical direction Dv (vertical direction in FIGS. 1 and 2), which is a direction perpendicular to the horizontal plane, to the outlet section 302 on the lower side. The inlet portion 301 has a cylindrical shape extending in the vertical direction Dv. An outlet section 302 is connected to the lower part of the inlet section 301 . Therefore, the garbage W thrown into the entrance section 301 falls downward according to gravity.

Hereinafter, for convenience of explanation, the upper side in the vertical direction Dv (the upper side in FIGS. 1 and 2) will be simply referred to as "upper side Dvu." Further, the side opposite to the upper side Dvu (the lower side in FIGS. 1 and 2) is simply referred to as the "lower side Dvd."

The outlet portion 302 is an outlet portion of the hopper 300 that guides the waste W input into the inlet portion 301 to the processing space V inside the furnace body 2. The outlet portion 302 internally forms a storage space R for temporarily storing the waste W before supplying the waste W to the processing space V inside the furnace main body 2 . The outlet portion 302 in this embodiment has a box shape extending in the conveyance direction Da.

The feeder 310 is a device that supplies the waste W in the hopper 300 to the processing space V inside the furnace body 2. The feeder 310 is arranged so as to be able to reciprocate in the conveyance direction Da with respect to a floor surface 302a facing upward Dvu on the inner surface of the outlet section 302.

An end portion of one side Dal of the feeder 310 is connected to a feeder 310 drive mechanism (not shown) that reciprocates the feeder 310 using hydraulic pressure or the like. The feeder 310 is capable of reciprocating movement within the storage space R in the transport direction Da by a feeder 310 drive mechanism. That is, the feeder 310 is capable of moving forward and backward on the floor surface 302a at the outlet portion 302 from one side Dal to the other side Dar.

The feeder 310 has a plate shape that extends in the conveyance direction Da and the furnace width direction Dw and has a predetermined thickness. The feeder 310 has an upper surface 311 facing the upper side Dvu, and an extrusion surface 312 connected to the upper surface 311 and facing the other side Dar. Hereinafter, for convenience of explanation, the width direction of the furnace body 2, which is a direction perpendicular to each of the conveyance direction Da and the vertical direction Dv, will be referred to as the "furnace width direction Dw."

The upper surface 311 is a surface on which the waste W supplied from the inlet portion 301 is deposited. The extrusion surface 312 is a surface that extrudes the waste W accumulated on the floor surface 302a to the other side Dar. That is, the feeder 310 intermittently pushes out the waste W in the storage space R toward the processing space V by reciprocating itself in the transport direction Da at predetermined timing.

That is, the garbage W on the upper surface 311 of the feeder 310 and the garbage W on the floor surface 302a of the outlet section 302 are integrated in the storage space R. Therefore, when the extrusion surface 312 of the feeder 310 pushes out the waste W toward the processing space V side, the waste W accumulated on the upper surface 311 is also moved toward the processing space V side.

(stalker)
The stoker 4 is composed of a plurality of fire grates (not shown), and the plurality of fire grates form a stoker surface 4a to which the fuel supply mechanism 3 supplies waste W in a layered manner. The grate has a fixed grate and a movable grate.

The fixed grate is fixed to the surface of the wind box 5 facing the upper side Dvu of the wind box 5. By moving the movable grate to one side Dal (upstream side) and the other side Dar (downstream side) at a constant speed, the garbage W on the movable grate and the fixed grate (on the stoker surface 4a) is removed. are conveyed to the downstream side while stirring and mixing. The stoker 4 conveys the waste W supplied to the stoker surface 4a in a layered manner toward the discharge chute 6 while burning it.

Here, the furnace body 2 has a drying stage 50, a combustion stage 51, and a post-combustion stage 52 in this order from one side Dal. These drying stage 50, combustion stage 51, and post-combustion stage 52 partition the processing space V in the transport direction Da. The drying stage 50 is an area where the waste W supplied from the hopper 300 is dried on the stoker 4 prior to combustion. That is, since moisture evaporates in the drying stage 50, steam is mainly generated from the drying stage 50.

The combustion stage 51 and the post-combustion stage 52 are areas where dry waste W is burned on the stoker 4. In the combustion stage 51, diffusion combustion occurs due to pyrolysis gas generated from the waste W, and a luminous flame F is generated. In the post-combustion stage 52, fixed carbon combustion of the waste W after diffusion combustion occurs, so no bright flame F is generated. Therefore, the luminous flame F generated due to combustion is mainly formed in the combustion stage 51.

(Wind box)
The wind box 5 supplies combustion air (primary air A1) from below the stoker 4 toward the processing space V. A plurality of wind boxes 5 are arranged in the conveyance direction Da. In this embodiment, the wind box 5 defines a drying stage 50, a combustion stage 51, and a post-combustion stage 52 in the furnace body 2.

(Discharge chute)
The discharge chute 6 is a device for dropping the garbage W that has become ash after combustion to the ash extrusion device 19 located on the lower side Dvd of the furnace body 2. The discharge chute 6 is provided at the end of the other side Dar of the after-combustion stage 52.

Here, as shown in FIG. 2, the furnace body 2 has a furnace bottom 203 and a ceiling part 200. The furnace tail 203 is a part of the partition wall in the furnace body 2. The furnace butt 203 is made of a refractory material or the like. The furnace tail 203 is arranged on the other side Dar than the post-combustion stage 52 partitioned by the wind box 5. The furnace tail 203 is connected to the discharge chute 6 from the upper side Dvu. The furnace tail 203 has a furnace tail surface 204 facing one side Dal. The furnace tail surface 204 in this embodiment has a planar shape that extends in the vertical direction Dv and the furnace width direction Dw.

The ceiling portion 200 is a part of the partition wall in the furnace body 2. The ceiling portion 200 is made of fireproof material or the like. The ceiling portion 200 is arranged above the furnace bottom 203 on the side Dvu. The ceiling portion 200 is inclined in such a direction that the height in the vertical direction Dv decreases toward the other side Dar. The end of the other side Dar in the ceiling section 200 is connected to the furnace tail 203. Hereinafter, for convenience of explanation, the connection point with the furnace tail 203 in the ceiling portion 200 will be referred to as the "rear end 201a." Further, the end of one side Dal of the ceiling portion 200 opposite to the rear end 201a is referred to as a "front end 201b."

The ceiling part 200 has a planar ceiling surface 201 and a curved surface 202 that is connected to the ceiling surface 201 from one side Dal and has a convex curved surface that faces upward Dvu toward the one side Dal. are doing. The ceiling surface 201 is connected to the furnace bottom surface 204 of the furnace bottom 203 from one side Dal. Therefore, the end of the other side Dar on the ceiling surface 201 is the rear end 201a. The ceiling surface 201 in this embodiment is arranged to face the post-combustion stage 52 in the vertical direction Dv.

The curved surface 202 is connected to the ceiling surface 201 from one side Dal. The curved surface 202 when viewed from the furnace width direction Dw is formed into an arc shape having a predetermined radius of curvature. Hereinafter, the length of the curved surface 202 when viewed from the furnace width direction Dw will be referred to as "X _R ".

(furnace)
The furnace 7 extends from the furnace body 2 toward the upper side Dvu. Exhaust gas G generated by combustion of waste W in the processing space V is sent to the exhaust heat recovery boiler 12 through the furnace 7. The furnace 7 has a cylindrical shape that extends in the vertical direction Dv and has an inner surface 70. The furnace 7 in this embodiment has a rectangular cross section.

The furnace 7 is connected to the ceiling part 200 from one side Dal. One side 70a of the inner surface 70 of the furnace 7 facing one side Dal is connected to the curved surface 202 of the ceiling part 200 from the upper side Dvu. Therefore, the connecting portion between the end of the lower side Dvd of the one surface 70a on the inner surface 70 and the end of the one side Dal on the curved surface 202 is the front end 201b. One surface 70a extends from the front end 201b so as to rise upward Dvu. Further, the furnace 7 is connected to the outlet portion 302 of the hopper 300 from the other side Dar. Therefore, the furnace 7 is arranged between the ceiling part 200 and the outlet part 302. The furnace 7 in this embodiment is arranged directly above the combustion stage 51.

(forced blower)
As shown in FIG. 1, the forced air blower 8 is a device that pumps air toward the inside of the combustion furnace 1 to combust the waste W in the processing space V. The forced air blower 8 includes a first forced air fan 81 and a second forced air fan 82. The first forced air blower 81 forces combustion air toward the wind box 5 through the primary air line 9 . The second forced air blower 82 forces air for combustion toward the furnace 7 through the secondary air line 11 .

(Primary air line)
The primary air line 9 is a pipe connecting the first forced air blower 81 and the wind box 5. By driving the first forced air blower 81, air necessary for combustion of the waste W is supplied to the wind box 5 through the primary air line 9. The primary air line 9 is connected to the wind box 5 from the lower side DVD. The air supplied to the wind box 5 is directed toward the garbage W from below the stoker 4. Hereinafter, for convenience of explanation, the air supplied into the furnace body 2 through the primary air line 9 will be referred to as "primary air A1."

The primary air line 9 has a primary air damper 90. The primary air damper 90 is placed midway through the primary air line 9, and regulates the flow rate of the primary air A1 in the primary air line 9 by the opening degree of the damper included in the primary air damper 90. .

(air preheater)
The air preheater 10 is a heat exchanger that preheats the air pressure-fed from the first forced air blower 81. The air preheater 10 is provided midway through the primary air line 9 and preheats the combustion air flowing from the first forced air blower 81 toward the wind box 5.

Combustion air preheated by the air preheater 10 is supplied into the processing space V, used for combustion of waste W, and exchanges heat with exhaust gas G generated as the waste W is burned. Therefore, the air preheater 10 can adjust the temperature of the exhaust gas G by adjusting the temperature of the combustion air.

(Secondary air line)
The secondary air line 11 is a pipe connecting the second forced air blower 82 and the furnace 7 . By driving the second forced air blower 82, air necessary for combustion of the waste W is supplied into the furnace 7 through the secondary air line 11. The secondary air line 11 penetrates the furnace 7 from the outside. As shown in FIG. 2, the tip of the secondary air line 11 is arranged inside the inner surface 70 of the furnace 7. Secondary air A2 supplied into the furnace 7 heads toward the waste W from above the stoker 4. Hereinafter, for convenience of explanation, the air supplied into the furnace body 2 through the secondary air line 11 will be referred to as "secondary air A2."

The secondary air line 11 has a secondary air damper 110. The secondary air damper 110 is provided in the middle of the secondary air line 11, and regulates the flow rate of the secondary air A2 by the opening degree of the damper that the secondary air damper 110 has.

(garbage pit)
As shown in FIG. 1, the garbage pit 18 stores garbage W and supplies the garbage W to the hopper 300. The garbage pit 18 includes a garbage pit main body 180, a platform 181, a crane 182, and a crane control device 189.

The garbage pit main body 180 is a chamber that stores garbage W on one side Dal from the combustion furnace 1. The garbage pit main body 180 is connected to the inlet portion 301 of the hopper 300. That is, the inside of the hopper 300 and the inside of the garbage pit main body 180 are in communication, and garbage W can be supplied from the inside of the garbage pit main body 180 to the inside of the hopper 300.

The platform 181 is an entrance for carrying garbage W into the inside of the garbage pit main body 180. The platform 181 is connected to a carry-in opening formed on one side Dal of the garbage pit main body 180. A garbage truck T is carried onto the platform 181 from outside the combustion equipment 100 . The garbage truck T throws the garbage W carried into the garbage pit main body 180.

The crane 182 grasps a portion of the garbage W stored in the garbage pit body 180 and transfers the grasped garbage W from the garbage pit body 180 to the entrance portion 301 of the hopper 300. The crane 182 is provided at the ceiling 200 minutes of the upper Dvu of the garbage pit main body 180.

The crane 182 includes a rail 183 provided on the ceiling, a girder 184 that runs along the rail 183, a trolley 185 that traverses this girder 184, a wire 186 suspended from this trolley 185, and this wire. It has a hoist 187 for hoisting and lowering the wire 186, and a grapple 188 attached to the tip of the wire 186.

The crane control device 189 is a device that controls the travel of the girder 184, the traverse of the trolley 185, the hoisting and lowering of the wire 186 by the hoist 187, the gripping operation of the grapple 188, and the like.

(Ash extrusion device)
The ash extrusion device 19 is a device that receives the garbage W (ash) that has fallen to the lower side DVD from the furnace main body 2 through the discharge chute 6, and pushes it out to the subsequent ash pit 20. The ash extrusion device 19 has an extrusion device main body 190 and an extrusion mechanism (not shown).

The extrusion device main body 190 receives the waste W that has been burned and turned into ashes in the processing space V, and temporarily deposits the waste W. The extrusion device main body 190 is arranged on the lower side DVD than the furnace main body 2. The extrusion device main body 190 is connected to the discharge chute 6 from the lower side DVD. The extrusion mechanism extrudes the garbage W (ash) that has fallen into the extrusion device main body 190 toward the ash pit 20.

(ash pit)
The ash pit 20 is a chamber that receives the waste W in the extrusion device and stores it therein. The ash pit 20 in this embodiment is connected to the extrusion device main body 190 from the other side Dar. The garbage W stored in the ash pit 20 is transferred to the outside of the combustion equipment 100 by, for example, an ash crane (not shown).

(Exhaust gas recirculation system)
The exhaust gas recirculation system 21 is an EGR (Exhaust Gas Recirculation) system that recirculates a part of the combustion exhaust gas G flowing through the outlet passage 15 into the furnace body 2 . The exhaust gas recirculation system 21 includes an exhaust gas recirculation line 22, a nozzle 23, and a fan 24.

(Exhaust gas recirculation line)
The exhaust gas recirculation line 22 connects the outlet channel 15 and the furnace body 2. One end of the exhaust gas recirculation line 22 in this embodiment is connected to the vicinity of the dust collector 14 in the outlet flow path 15, and the other end of the exhaust gas recirculation line 22 is connected to the furnace bottom in the furnace main body 2 via a nozzle 23. 203.

(nozzle)
The nozzle 23 is a circular nozzle that supplies (discharges) the exhaust gas G supplied through the exhaust gas recirculation line 22 into the furnace body 2 . Nozzle 23 is connected to the other end of exhaust gas recirculation line 22 . As shown in FIGS. 2 and 3, the nozzle 23 in this embodiment has a cylindrical shape extending around the center line O. As shown in FIGS. The nozzle 23 is fixed to the furnace bottom 203 in a state that it passes through the furnace bottom 203.

A plurality of nozzles 23 are arranged at the furnace bottom 203 at intervals in the furnace width direction Dw with the same height in the vertical direction Dv. In this embodiment, two nozzles 23 are arranged at the furnace bottom 203 with an interval in the furnace width direction Dw. Note that in FIG. 2, only one nozzle 23 is shown due to space limitations.

The nozzle 23 opens into the inside of the furnace body 2 in a state facing the inside of the furnace body 2 . The nozzle 23 is fixed to the furnace bottom 203 so that the center of the opening is aligned with the furnace bottom surface 204. In this embodiment, the exhaust gas G discharged from the nozzle 23 spreads conically around the opening of the nozzle 23 . Hereinafter, the opening diameter of the nozzle 23 in this embodiment will be referred to as "D".

Here, the horizontal distance between the rear end 201a and the front end 201b is "X", the vertical distance between the front end 201b and the center of the opening of the nozzle 23 is "H", and the ceiling and the horizontal plane Hp are The angle formed by the center line O of the nozzle 23 and the horizontal plane Hp is defined as "β". In this case, the nozzle 23 is arranged at the furnace tail 203 so as to satisfy the following formula (I).
atan((H/X)+tan(α))-β<10...(I)

Note that the horizontal distance here means a two-dimensional geometric distance in the horizontal direction. Further, the vertical distance means a one-dimensional geometric distance in the vertical direction Dv. Further, “atan((H/X)+tan(α))−β” on the left side of formula (I) is greater than 0.

The process of deriving formula (I) will be explained below. The vertical distance between the front end 201b and the rear end 201a is "H1", the vertical distance between the rear end 201a and the center of the opening of the nozzle 23 is "H2", and the center line O of the nozzle 23 is used as a reference. When the release angle of the exhaust gas G is set to "γ", the following formula (II) holds true. Note that γ is larger than 0.
atan((H1+H2)/X)<β+γ...(II)

When formula (II) is transformed, the following formula (III) is obtained.
atan((H1/X)+(H2/X))<β+atan(0.172)...(III)

Here, 0.172 on the right side of equation (III) is an experimental constant. That is, as shown in FIG. 3, a predetermined distance from the center of the opening of the nozzle 23 on the center line O is defined as "D1", and the center line at a position away from the center of the opening of the nozzle 23 by this predetermined distance When the distance that the exhaust gas G spreads from O is "D2", the following formula (IV), that is, by substituting the following formula (IV) into the above formula (II) in relation to the above γ, the above formula (III) holds true.
γ=atan(D2/D1)=atan(0.172)...(IV)

When the above formula (III) is transformed, the following formula (V), that is, the above formula (I) is derived.
atan((H/X)+tan(α))-β<9.759...≒10...(V)

Here, the opening diameter of the nozzle 23 is determined by the following formula ( _VI ) is set so that it is satisfied.
X _R /D<52...(VI)

Further, in the present embodiment, it is desirable that um calculated from the following formula (VII) satisfies the following formula (VIII) in relation to the left-hand side portion (X _R /D) in the formula (VI).
um=3.5(D/D1) ^0.5 u ₀ ...(VII)
um>1.5exp (0.0768X _R /D)...(VIII)

Note that u ₀ in equation (VII) is the nozzle flow velocity determined by the type of nozzle 23 and the like. In addition, the source of formula (VII) is Toshihiko Shakawachi, "Jet Current Engineering", Morikita Publishing (2004). Formula (VIII) is a predictive formula established by the inventors based on test data quoted from Toshihiko Shakawachi, "Proceedings of the Japan Society of Mechanical Engineers (B edition)", 56, 532 (1990). .

(fan)
Fan 24 supplies exhaust gas G to nozzle 23 through exhaust gas recirculation line 22 . As shown in FIG. 1, the fan 24 is placed midway through the exhaust gas recirculation line 22. The fan 24 is driven to force-feed a portion of the exhaust gas G in the outlet flow path 15 to the nozzle 23 . The fan 24 is controlled by a control device 30 located outside the combustion furnace 1.

Specifically, fan 24 receives a signal indicating the rotation speed from control device 30 via wired or wireless communication. That is, the fan 24 rotates based on the rotational speed indicated by the signal, draws out a part of the exhaust gas G in the outlet flow path 15 from the outlet flow path 15, and sends the air toward the nozzle 23. Further, the fan 24 transmits a signal indicating its own output rotation speed to the control device 30 at predetermined time intervals via wired or wireless communication.

(Movement of exhaust gas released from the nozzle)
The movement of the exhaust gas G discharged into the furnace body 2 by the nozzle 23 will be described below. As shown in FIG. 2, a portion of the exhaust gas G discharged from the nozzle 23 that satisfies the relationship expressed by the above formula (I) collides with the ceiling surface 201 of the ceiling portion 200 from the lower side Dvd. Hereinafter, for convenience of explanation, the exhaust gas G discharged from the nozzle 23 will be referred to as "nozzle gas".

The nozzle gas colliding with the ceiling surface 201 forms a wall jet Jw that spreads along the ceiling surface 201 in a flattened state. The nozzle gas flows toward one side Dal along the ceiling surface 201 while forming a wall jet flow Jw. That is, the wall jet Jw forms a sheet shape that spreads along the ceiling surface 201. At this time, the nozzle gases discharged from the two nozzles 23 each follow the ceiling surface 201 to form a wall jet Jw that merges with each other.

A part of the wall jet Jw that reaches the curved surface 202 disposed on one side Dal from the ceiling surface 201 travels straight in the direction in which the ceiling surface 201 spreads. Hereinafter, for convenience of explanation, this wall jet Jw that goes straight to the other side Dar in the direction in which the ceiling surface 201 spreads via the curved surface 202 will be referred to as a "first jet Jw1." The first jet flow Jw1 flows from the lower side Dvd to cover the upper side Dvu of the combustion stage 51 among the openings of the furnace 7 facing the lower side Dvd.

On the other hand, among the wall jets Jw that have reached the curved surface 202, a portion of the wall jet Jw that is different from the first jet Jw1 flows into the furnace 7 along the curved shape of the curved surface 202. That is, this wall jet Jw flows toward the upper side Dvu inside the furnace 7 on the upper side Dvu than the first jet Jw1 due to the Coanda effect. Hereinafter, for convenience of explanation, this wall jet Jw that advances into the interior of the furnace 7 along the curved shape of the curved surface 202 will be referred to as a "second jet Jw2." In addition, in FIG. 2, for simplicity of explanation, only the flows of the first jet Jw1 and the second jet Jw2 of the wall jet Jw that have passed through the bend are shown by hatching.

(Exhaust gas concentration acquisition section)
The exhaust gas concentration acquisition unit 25 acquires the concentrations of CO and _NOx contained in the exhaust gas G generated from the combustion furnace 1. The exhaust gas concentration acquisition section 25 is arranged within the outlet flow path 15. The exhaust gas concentration acquisition section 25 includes a CO sensor 25a and a _NOX sensor 25b. Hereinafter, the concentration of CO contained in the exhaust gas G will be referred to as "CO concentration", and the concentration of NO _X contained in exhaust gas G will be referred to as "NO _X concentration".

The CO sensor 25a acquires the CO concentration of the exhaust gas G flowing in the outlet flow path 15 at predetermined time intervals, and transmits a signal indicating the CO concentration to the control device 30 via wired or wireless communication. The NO _X sensor 25b acquires the NO _X concentration of the exhaust gas G flowing in the outlet flow path 15 at predetermined time intervals, and transmits a signal indicating the NO _X concentration to the control device 30 via wired or wireless communication. The CO sensor 25a and the _NOX sensor 25b in this embodiment obtain, for example, the CO concentration and _NOX concentration in the exhaust gas G per unit flow rate.

(Control device)
The control device 30 adjusts the flow rate of the exhaust gas G discharged from the nozzle 23 by transmitting and receiving signals with the various devices described above. As shown in FIG. 4, the control device 30 in this embodiment includes a detection section 31, a determination section 32, an adjustment section 33, and a storage section 34.

(Detection unit)
The detection unit 31 receives signals indicating the CO concentration acquired by the CO sensor 25a of the exhaust gas concentration acquisition unit 25 and _{the NO} Detect CO concentration and _NOx concentration. The detection unit 31 transmits a signal indicating the detection results (CO concentration and _NOx concentration) to the determination unit 32 and adjustment unit 33.

(Judgment Department)
The determination unit 32 determines whether each of the CO concentration and _NOx concentration detected by the detection unit 31 is an appropriate concentration. Specifically, the determination unit 32 compares the CO concentration detected by the detection unit 31 and the CO concentration threshold stored in the storage unit 34.

The determination unit 32 determines that “the CO concentration is appropriate” when the CO concentration detected by the detection unit 31 is less than or equal to the CO concentration threshold. On the other hand, when the CO concentration detected by the detection unit 31 is larger than the CO concentration threshold, the determination unit 32 determines that “the CO concentration is not appropriate”.

Furthermore, when the NO _X concentration detected by the detection section 31 is less than or equal to the NO _X concentration threshold, the determining section 32 determines that "the NO _X concentration is appropriate". On the other hand, when the NO _X concentration detected by the detection section 31 is greater than the NO _X concentration threshold, the determination section 32 determines that "the NO _X concentration is not appropriate." The determination unit 32 transmits a signal indicating the determination result to the adjustment unit 33.

(adjustment section)
The adjustment unit 33 adjusts the flow rate of the exhaust gas G supplied into the furnace body 2 by the nozzle 23 when receiving the CO concentration and _NOx concentration transmitted from the detection unit 31. Further, the adjustment unit 33 adjusts the flow rate of the exhaust gas G supplied into the furnace body 2 by the nozzle 23 based on the determination result of the determination unit 32.

When the adjustment unit 33 receives the CO concentration from the detection unit 31, it transmits a signal to the fan 24 indicating that the rotation speed has increased. On the other hand, when the adjustment unit 33 receives the _NOx concentration from the detection unit 31, it transmits a signal to the fan 24 indicating that the rotation speed has increased.

Furthermore, when the determination unit 32 determines that “the CO concentration is appropriate”, the adjustment unit 33 transmits a signal to the fan 24 indicating that the rotation speed has decreased. On the other hand, when the determination unit 32 determines that “the CO concentration is not appropriate”, the adjustment unit 33 transmits a signal to the fan 24 indicating that the rotation speed should be increased.

Furthermore, when the determination unit 32 determines that “the _NOx concentration is appropriate”, the adjustment unit 33 transmits a signal to the fan 24 indicating that the rotation speed has decreased. On the other hand, when the determination unit 32 determines that “ _NOx concentration is not appropriate”, the adjustment unit 33 transmits a signal to the fan 24 indicating that the rotation speed should be increased.

(Operation of control device)
Next, the operation of the control device 30 will be explained. Hereinafter, with reference to FIG. 5, an example of the operation of the control device 30 when the detection section 31 receives a signal indicating the CO concentration from the exhaust gas concentration acquisition section 25 will be described.

The detection unit 31 detects the CO concentration contained in the exhaust gas G in the outlet flow path 15 by receiving the CO concentration from the exhaust gas concentration acquisition unit 25 (step S0). Next, when the adjustment unit 33 receives the detection result from the detection unit 31, it transmits a signal indicating an increase in the rotation speed to the fan 24, and increases the flow rate of the exhaust gas G supplied to the inside of the furnace body 2. (Step S1).

Next, when the determination unit 32 receives the detection result from the detection unit 31, it determines whether the CO concentration detected by the detection unit 31 is an appropriate concentration (step S2). When the determination unit 32 determines that “the CO concentration is appropriate” (step S2: YES), the adjustment unit 33 transmits a signal indicating a decrease in rotation speed to the fan 24 to supply the inside of the furnace body 2. The flow rate of the exhaust gas G is lowered (step S3). When the process of step S3 is completed, the process of step S0 is performed again.

If the determination unit 32 determines that “the CO concentration is not appropriate” (step S2: NO), the adjustment unit 33 receives the determination result from the determination unit 32 and sends a signal to the fan 24 indicating that the rotation speed has increased. , the flow rate of the exhaust gas G supplied to the inside of the furnace body 2 is increased (step S1'). When the process of step S1' is completed, the process of step S2 is performed again.

The processes from step S0 to step S3 described above are repeatedly executed during the operation stage of the combustion equipment 100.

Next, with reference to FIG. 6, an example of the operation of the control device 30 when the detection section 31 receives a signal indicating the _NOx concentration from the exhaust gas concentration acquisition section 25 will be described.

The detection unit 31 detects the _{NOX concentration contained in the exhaust gas G in the outlet flow path 15 by receiving the NOX concentration} from the exhaust gas concentration acquisition unit 25 (step S10). Next, when the adjustment unit 33 receives the detection result from the detection unit 31, it transmits a signal indicating an increase in the rotation speed to the fan 24, and increases the flow rate of the exhaust gas G supplied to the inside of the furnace body 2. (Step S11).

Next, when the determination unit 32 receives the detection result from the detection unit 31, it determines whether the NO _X concentration detected by the detection unit 31 is an appropriate concentration (step S12). If the determination unit 32 determines that “the _NO The flow rate of the supplied exhaust gas G is reduced (step S13). When the process of step S13 is completed, the process of step S10 is performed again.

If the determination unit 32 determines that “the _NO Then, the flow rate of the exhaust gas G supplied to the inside of the furnace body 2 is increased (step S11'). When the process of step S11' is completed, the process of step S12 is performed again.

The processes from step S10 to step S13 described above are repeatedly executed during the operation stage of the combustion equipment 100.

(effect)
According to the combustion equipment 100 according to the embodiment described above, the nozzle 23 is arranged at the furnace tail 203 in such a direction that the nozzle gas forms a wall jet Jw along the ceiling 200 of the furnace body 2. As a result, part of the exhaust gas G that rises as the garbage W burns on the lower side Dvd than the wall jet Jw collides with the wall jet Jw from the lower side Dvd. A part of the exhaust gas G that collided with the wall jet Jw is bounced back to the lower side Dvd and remains inside the furnace body 2. Therefore, the exhaust gas G is prevented from directly flowing into the furnace 7, and mixing with unburned gas such as CO inside the furnace body 2 is strengthened, so that the exhaust gas G remains inside the furnace body 2. time can be increased. As a result, increases in the CO concentration and _NOX concentration in the exhaust gas G in the furnace body 2 can be suppressed.

Here, when the nozzle gas discharged from the plurality of nozzles 23 forms a free jet that does not follow the ceiling portion 200, a gap may occur between the free jets discharged from each nozzle 23. At this time, the exhaust gas G generated by the combustion of the waste W may slip through the gap between the free jets to the upper side Dvu. According to the combustion equipment 100 according to the above embodiment, the nozzle gas discharged from the plurality of nozzles 23 becomes a wall jet Jw that merges with each other by following the ceiling surface 201 in the ceiling part 200, and is therefore discharged from each nozzle 23. A gap is less likely to occur between the wall jets Jw formed by the nozzle gas. Therefore, it is possible to suppress the exhaust gas G generated due to the combustion of the garbage W from slipping through to the upper side Dvu than the wall jet flow Jw. As a result, the residence time of the exhaust gas G inside the furnace body 2 can be further increased. In addition, volatile matter generated from the waste W is suppressed from existing in a locally high concentration state in the lower part of the furnace 7 (lower side Dvd than the connection part between the furnace 7 and the secondary air line 11). be able to.

Furthermore, since the nozzle gas forms a flattened wall jet Jw along the ceiling surface 201, the jet width in the vertical direction Dv of the nozzle gas can be suppressed to a smaller value than, for example, when the nozzle gas forms a free jet. . As a result, compared to the case where the nozzle gas forms a free jet flow, the position where the exhaust gas G is accelerated by colliding with the nozzle gas is more on the upper side Dvu. In other words, the residence time of the exhaust gas G inside the furnace body 2 can be increased. Therefore, compared to the case where the nozzle gas forms a free jet flow, the exhaust gas G can remain inside the furnace body 2 for a longer time.

Further, according to the combustion equipment 100 according to the above embodiment, the nozzle 23 is arranged at the furnace tail 203 so as to satisfy the above formula (I). Thereby, a wall jet flow Jw along the ceiling portion 200 can be effectively formed inside the furnace main body 2 . Moreover, the above-mentioned effects can be realized with specific settings.

Further, according to the combustion equipment 100 according to the above embodiment, the ceiling portion 200 has the curved surface 202 that connects the ceiling surface 201 and the inner surface 70 of the furnace 7 . As a result, the curved surface 202 exerts a Coanda effect on the wall jet Jw. That is, a part of the wall jet Jw flowing along the ceiling surface 201, ie, the second jet Jw2, flows along the curved surface 202 and flows inside the furnace 7 toward the upper side Dvu. The second jet flow Jw2 that has flowed toward the upper side Dvu spreads and flows within the furnace 7, and mixes with the exhaust gas G that is generated along with the combustion of the waste W and that has flowed into the furnace 7. As a result, the uneven distribution of CO and _NOx in the exhaust gas G in the furnace 7 can be suppressed.

Further, according to the control device 30 according to the embodiment, the adjustment unit 33 determines one of the CO concentration and the _NO When the above increases or decreases, the rotation speed of the fan 24 is increased or decreased. Thereby, the CO concentration and the NO _X concentration in the exhaust gas G inside the furnace body 2 and the exhaust gas G discharged to the outside of the furnace body 2 can be optimized. For example, when CO or _NOx is detected by the detection unit 31, the adjustment unit 33 increases the rotation speed of the fan 24, thereby enhancing the above-mentioned effects. As a result, the CO concentration and _NOX concentration in the exhaust gas G can be reduced.

(Other embodiments)
As above, the embodiments of the present disclosure have been described in detail with reference to the drawings, but the specific configuration is not limited to the configuration of each embodiment, and additions of configurations may be made without departing from the gist of the present disclosure. Omissions, substitutions, and other changes are possible.

Note that FIG. 7 is a hardware configuration diagram showing the configuration of the computer 1100 according to this embodiment. Computer 1100 includes a processor 1110, main memory 1120, storage 1130, and interface 1140.

The control device 30 described above is implemented in the computer 1100. The operations of each processing unit described above are stored in the storage 1130 in the form of a program. Processor 1110 reads the program from storage 1130, expands it to main memory 1120, and executes the above processing according to the program. Further, the processor 1110 reserves a storage area corresponding to the storage unit 34 described above in the main memory 1120 according to the program.

The program may be for implementing part of the functions that the computer 1100 performs. For example, the program may function in combination with other programs already stored in the storage 1130 or in combination with other programs installed in other devices. Further, the computer 1100 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or in place of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, part or all of the functions implemented by processor 1110 may be implemented by the integrated circuit.

Examples of the storage 1130 include a magnetic disk, a magneto-optical disk, a semiconductor memory, and the like. Storage 1130 may be internal media connected directly to the bus of computer 1100, or external media connected to computer 1100 via interface 1140 or a communication line. Further, when this program is distributed to the computer 1100 via a communication line, the computer 1100 that received the distribution may develop the program in the main memory 1120 and execute the above processing. In the embodiments described above, storage 1130 is a non-transitory tangible storage medium.

Further, the program may be for realizing part of the functions described above.
Furthermore, the program may be a so-called difference file (difference program) that implements the above-described functions in combination with other programs already stored in the storage 1130.

Furthermore, in the embodiment, a configuration has been described in which the two nozzles 23 are arranged at the furnace bottom 203 at intervals in the furnace width direction Dw, but the present invention is not limited to this configuration. One nozzle 23 may be arranged at the furnace tail 203. Moreover, three or more nozzles 23 may be arranged in the furnace tail 203 at intervals in the furnace width direction Dw.

Further, the ceiling portion 200 described in the embodiment may be formed of a material with higher wear resistance than the furnace bottom 203. An example of a highly wear-resistant material used for the ceiling portion 200 is SiC (silicon carbide). Thereby, even if the fly ash (ash) contained in the wall jet flow Jw collides with the ceiling part 200, wear of the ceiling part 200 can be suppressed. Further, in addition to the above configuration, the furnace 7 may be formed of a material having higher wear resistance than the furnace butt 203.

Further, in the embodiment, a configuration in which the nozzle 23 is a circular nozzle has been described, but the nozzle is not limited to a circular nozzle.

Further, in the embodiment, the combustion equipment 100 is a stoker-type combustion furnace, but it is not limited to a stoker-type combustion furnace. The combustion equipment 100 may be, for example, a kiln stoker furnace, a biomass fluidized bed boiler, a sludge combustion furnace, or the like. Therefore, the above-described control device 30 may be a control device for combustion equipment 100 such as a kiln stoker furnace, a biomass fluidized bed boiler, a sludge combustion furnace, or the like.

<Additional notes>
The combustion equipment 100 and the control device 30 described in the embodiment can be understood, for example, as follows.

(1) The combustion equipment 100 according to the first aspect includes a furnace body 2 that transports the incineration material W while burning it inside, and a part of the exhaust gas G discharged from the furnace body 2. a nozzle 23 for supplying the inside of the furnace, and the nozzle 23 is oriented so that the exhaust gas G supplied to the inside of the furnace main body 2 forms a wall jet flow Jw along the ceiling 200 of the furnace main body 2. It is arranged at the bottom 203 of the main body 2.

As a result, part of the exhaust gas G that rises as the incineration material W burns on the lower side Dvd than the wall jet Jw collides with the wall jet Jw from the lower side Dvd. A part of the nozzle gas that collided with the wall jet Jw is bounced back to the lower side Dvd and remains inside the furnace body 2.

(2) The combustion equipment 100 according to the second aspect is the combustion equipment 100 of (1), in which a plurality of the nozzles 23 are arranged at the furnace bottom 203, and the plurality of nozzles 23 are arranged so that the exhaust gas G is The jets may be arranged along the ceiling 200 to form the wall jet Jw that merges with each other.

This makes it difficult for gaps to occur between the wall jets Jw formed by the exhaust gas G discharged from each nozzle 23. Therefore, it is possible to suppress the exhaust gas G generated due to the combustion of the material to be incinerated W from slipping through to the upper side Dvu than the wall jet flow Jw.

(3) The combustion equipment 100 according to the third aspect is the combustion equipment 100 of (1) or (2), in which the ceiling part 200 is connected to the furnace bottom 203 and the The height in the vertical direction Dv decreases as the W goes in the conveying direction, and the rear end 201a, which is the connection point with the furnace bottom 203 in the ceiling part 200, and the The horizontal distance between the rear end 201a and the front end 201b on the opposite side is X, the vertical distance between the front end 201b and the center of the opening of the nozzle 23 is H, and the distance between the ceiling part 200 and the horizontal plane Hp is The nozzle 23 has the following relationship: atan((H/X)+tan(α))−β< 10 may be arranged at the furnace bottom 203 so as to meet the requirements.

Thereby, the above effect can be realized with specific settings.

(4) The combustion equipment 100 according to the fourth aspect is the combustion equipment 100 of (3), and further includes a furnace 7 extending upward from the furnace body 2 and having an inner surface 70 connected to the ceiling portion 200. , the ceiling part 200 connects a planar ceiling surface 201, the inner surface 70, and the ceiling surface 201, and forms a curved surface that faces upward as it goes from the ceiling surface 201 to the inner surface 70. It may have a curved surface 202.

As a result, the curved surface 202 exerts a Coanda effect on the wall jet Jw. That is, a part of the wall jet Jw flowing along the ceiling surface 201 flows along the curved surface 202 and flows inside the furnace 7 toward the upper side Dvu.

(5) The control device 30 according to the fifth aspect is the control device 30 of the combustion equipment 100 according to any one of (1) to (4), in which the combustion equipment 100 is connected to the combustion equipment 100 through the exhaust gas recirculation line 22. It further includes a fan 24 that supplies part of the exhaust gas G to the nozzle 23, and a detection unit 31 that detects the CO concentration and _NO and an adjustment section 33 that increases or decreases the rotation speed of the fan 24 when one or more of the CO concentration and _NOx concentration in the air increases or decreases.

Thereby, the CO concentration and the NO _X concentration in the exhaust gas G inside the furnace body 2 and the exhaust gas G discharged to the outside of the furnace body 2 can be optimized.

1... Combustion furnace 2... Furnace body 3... Fuel supply mechanism 4... Stoker 4a... Stoker surface 5... Wind box 6... Discharge chute 7... Furnace 8... Forced blower 9... Primary air line 10... Air preheater 11... Secondary Air line 12...Exhaust heat recovery boiler 13...Reducing temperature tower 14...Dust collector 15...Outlet channel 16...Chimney 17...Induction fan 18...Garbage pit 19...Ash extrusion device 20...Ash pit 21...Exhaust gas recirculation system 22 ...Exhaust gas recirculation line 23...Nozzle 24...Fan 25...Exhaust gas concentration acquisition unit 25a... _CO sensor 25b...NO 51... Combustion stage 52... After combustion stage 70... Inner surface 70a... One side 81... First forced air blower 82... Second forced air blower 90... Primary air damper 100... Combustion equipment 110... Secondary air damper 180... Garbage pit body 181 ... Platform 182 ... Crane 183 ... Rail 184 ... Girder 185 ... Trolley 186 ... Wire 187 ... Hoisting machine 188 ... Grapple 189 ... Crane control device 190 ... Extrusion device main body 200 ... Ceiling part 201 ... Ceiling surface 201a ... Rear end 201b ... Front end 202...Curved surface 203...Furnace bottom 204...Furnace bottom surface 300...Hopper 301...Inlet part 302...Outlet part 302a...Floor surface 310...Feeder 311...Top surface 312...Extrusion surface 1100...Computer 1110...Processor 1120...Main memory 1130... Storage 1140...Interface A1...Primary air A2...Secondary air Da...Transportation direction Dal...One side Dar...Other side Dv...Vertical direction Dvd...Downside Dvu...Upper side Dw...Furnace width direction F...Glow flame G...Exhaust gas Hp...Horizontal plane Jw...Wall jet Jw1...First jet Jw2...Second jet O...Center line R...Storage space R1...Primary combustion area R2...Secondary combustion area T...Garbage truck V...Processing space W...Incineration things, garbage

In order to solve the above problems, the combustion equipment according to the present disclosure includes a furnace body that transports the material to be incinerated while burning it inside, and a part of the exhaust gas discharged from the furnace body that is supplied to the inside of the furnace body. a nozzle, the nozzle is arranged at the bottom of the furnace body in such a direction that the exhaust gas supplied into the furnace body forms a wall jet along the ceiling of the furnace body, The nozzle supplies the exhaust gas from an opening of the nozzle so as to spread conically, so that a part of the exhaust gas collides with the ceiling of the furnace body from below, forming the wall jet, and A plurality of nozzles are arranged at intervals in the road width direction at the furnace bottom, and the intervals between the plurality of nozzles are set such that the wall jet in which the exhaust gases supplied from each nozzle are combined with each other is formed. is set.

Claims (5)

A furnace body that transports the material to be incinerated while burning it inside;
a nozzle that supplies a part of the exhaust gas discharged from the furnace body into the inside of the furnace body;
Equipped with
In the combustion equipment, the nozzle is arranged at the bottom of the furnace body in such a direction that the exhaust gas supplied into the furnace body forms a wall jet along the ceiling of the furnace body. A plurality of the nozzles are arranged at the bottom of the furnace,
The combustion equipment according to claim 1, wherein the plurality of nozzles are arranged so that the exhaust gas flows along the ceiling to form the wall jet that merges with each other. The ceiling part is connected to the bottom of the furnace and is inclined in such a direction that the height in the vertical direction decreases as the incineration material goes in the direction in which the material to be incinerated is transported;
The horizontal distance between the rear end of the ceiling, which is the connection point to the furnace bottom, and the front end of the ceiling, which is opposite to the rear end, is X;
Let H be the vertical distance between the front end and the center of the nozzle opening,
Let α be the angle formed by the ceiling part and the horizontal plane,
When the angle between the center line of the nozzle and the horizontal plane is β,
The nozzle is
atan((H/X)+tan(α))−β<10
The combustion equipment according to claim 1 or 2, wherein the combustion equipment is arranged at the bottom of the furnace so as to satisfy the following. further comprising a furnace extending upward from the furnace body and having an inner surface connected to the ceiling,
The ceiling section is
A ceiling surface forming a planar shape,
a curved surface that connects the inner surface and the ceiling surface and is curved upward as it goes from the ceiling surface toward the inner surface;
The combustion equipment according to claim 3, having: A control device for a combustion equipment according to any one of claims 1 to 4,
The combustion equipment further includes a fan that supplies a portion of the exhaust gas to the nozzle through an exhaust gas recirculation line,
a detection unit that detects CO concentration and _NOX concentration in the exhaust gas;
an adjustment unit that increases or decreases the rotation speed of the fan when one or more of the CO concentration and _NOx concentration in the exhaust gas increases or decreases based on the detection result of the detection unit;
A control device having:

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