Catalyst-free denitration system, combustion equipment, denitration method and expansion nozzle

Abstract

A catalyst-free denitration system is provided with: a denitration agent supply unit including a nozzle which is provided in a flow path through which a combustion gas flows in a combustion facility and which is capable of adjusting a denitration agent injection angle with respect to the flow direction of the combustion gas; and a control unit that controls the injection angle of the nozzle on the basis of information relating to the temperature of the combustion gas.

Description

Technical Field

[0001] This invention relates to a catalyst-free denitrification system, combustion equipment, denitrification method, and extended nozzle.

[0002] This application claims priority to Japanese Patent Application No. 2023-051311, filed on March 28, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] Patent Document 1 discloses a catalyst-free denitrification device that uses urea water or ammonia water as a denitrification agent to denitrate the gas inside the boiler. In this catalyst-free denitrification device, denitrification agent injection nozzles that inject denitrification agent into the boiler are arranged at multiple locations at different heights. Based on the boiler's operating load, the denitrification agent injection nozzle located at the height position with the highest reaction efficiency of the denitrification agent is determined from among the multiple denitrification agent injection nozzles. Only the determined denitrification agent injection nozzle is used to inject the denitrification agent, thereby preventing a decrease in denitrification efficiency.

[0004] Patent Document 2 discloses a combustion device in which the nitrogen oxide concentration corresponding to the calculated exhaust gas volume is determined by using a relationship between the exhaust gas volume immediately preceding the reductant supply position and the nitrogen oxide concentration at the incinerator outlet side, which is measured in advance in an incinerator. The denitrification rate is then calculated based on the calculated nitrogen oxide concentration and a target nitrogen oxide concentration. The reductant supply amount is determined based on data representing the relationship between the pre-calculated denitrification rate and the equivalent ratio (reductant / nitrogen oxide) of the reductant used to achieve that denitrification rate. In this combustion device, supply nozzles are arranged at multiple locations (e.g., three locations) at intervals of 1 to 3 meters in the exhaust gas flow direction. The desired supply nozzle is selected from among the multiple supply nozzles according to the combustion load.

[0005] Previous technical documents

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2006-64291

[0008] Patent Document 2: Japanese Patent No. 6049809 Summary of the Invention

[0009] The technical problem to be solved by the invention

[0010] However, if multiple nozzles are configured as in Patent Document 1 or Patent Document 2, depending on the situation, the construction of the multiple nozzles or the surrounding structures associated with the configuration of the multiple nozzles may become complicated.

[0011] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a catalyst-free denitrification system, combustion equipment, denitrification method and extended nozzle that can improve the workability.

[0012] means for solving technical problems

[0013] To address the aforementioned issues, the catalystless denitrification system of the present invention comprises: a denitrification agent supply unit including a nozzle disposed in a flow path for supplying combustion gas in a combustion device and capable of adjusting the denitrification agent injection angle relative to the flow direction of the combustion gas; and a control unit that controls the injection angle of the nozzle based on information related to the temperature of the combustion gas.

[0014] To address the aforementioned issues, the combustion apparatus of the present invention includes a flow path for supplying combustion gases within the combustion apparatus and a catalyst-free denitrification system. The catalyst-free denitrification system includes: a denitrification agent supply unit comprising a nozzle disposed in the flow path and capable of adjusting the denitrification agent injection angle relative to the flow direction of the combustion gases; and a control unit that controls the injection angle of the nozzle based on information related to the temperature of the combustion gases.

[0015] To address the aforementioned issues, the denitrification method of the present invention is a denitrification method that injects a denitrification agent into the flow path of the combustion gas in a combustion device. The method includes: changing the injection angle based on information related to the temperature of the combustion gas, wherein the injection angle is the injection angle relative to the flow direction of the combustion gas and is the injection angle from which the denitrification agent is injected from the nozzle.

[0016] To address the aforementioned issues, the extended nozzle of the present invention comprises: a stationary portion, which is connected to a pipe in a combustion device to receive a denitrifying agent; a movable portion, which is rotatably connected to the stationary portion and includes a nozzle capable of spraying the denitrifying agent flowing from the pipe into the stationary portion to the outside; and an adjustment mechanism capable of adjusting the angle of the movable portion relative to the stationary portion.

[0017] Effects of the Invention

[0018] The catalyst-free denitrification system, combustion equipment, denitrification method, and extended nozzle of the present invention can improve workability. Attached Figure Description

[0019] Figure 1 This is a diagram showing the overall structure of the combustion device according to the first embodiment of the present invention.

[0020] Figure 2 It is Figure 1 The magnified 3D representation of the area enclosed by line F2.

[0021] Figure 3 This is a cross-sectional view showing the nozzle according to the first embodiment of the present invention.

[0022] Figure 4 This is a cross-sectional view showing the nozzle according to the first embodiment of the present invention.

[0023] Figure 5 This is a block diagram illustrating the functional structure related to denitrification in the first embodiment of the present invention.

[0024] Figure 6 This is a graph showing the relationship between the reaction temperature and the denitrification rate in the first embodiment of the present invention.

[0025] Figure 7 This is a diagram illustrating the control of the injection angle in the first embodiment of the present invention.

[0026] Figure 8 This is a flowchart illustrating the control flow of the first embodiment of the present invention.

[0027] Figure 9 This is a diagram illustrating the effect of the jet angle adjustment according to the first embodiment of the present invention.

[0028] Figure 10 This is a cross-sectional view of a nozzle, representing a modified example of the first embodiment of the present invention.

[0029] Figure 11 This is a perspective view of the stove according to the second embodiment of the present invention.

[0030] Figure 12 This is a diagram illustrating another aspect of the temperature detection unit in the second embodiment of the present invention.

[0031] Figure 13 This is an infrared image used to illustrate the second embodiment of the present invention.

[0032] Figure 14 This is a block diagram illustrating the functional structure related to denitrification in the second embodiment of the present invention.

[0033] Figure 15 This is a diagram illustrating the control of the injection quantity in the second embodiment of the present invention.

[0034] Figure 16 This is a flowchart illustrating the control flow of the second embodiment of the present invention.

[0035] Figure 17 This is a diagram illustrating the effect of the injection volume adjustment in the second embodiment of the present invention.

[0036] Figure 18 This is a hardware structure diagram illustrating the computer structure of an embodiment of the present invention. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, structures having the same or similar functions are labeled with the same symbols. Furthermore, repeated descriptions of these structures may sometimes be omitted. In the present invention, "according to XX" means "at least according to XX," and may also include cases where it is based on other elements besides XX. Furthermore, "according to XX" is not limited to the direct use of XX, and may also include cases where it is obtained by performing calculations or processing on XX. In the present invention, "XX or YY" is not limited to either XX or YY, and may also include both XX and YY. This is also true when there are three or more selective elements. "XX" and "YY" are arbitrary elements (e.g., arbitrary information).

[0038] In the embodiments described below, for ease of explanation, the side from the furnace body 20 toward the hopper 11 (described later) is defined as "front," and the opposite direction is defined as "rear." Furthermore, "left" and "right" are defined based on the direction from the furnace body 20 toward the hopper 11.

[0039] (First Embodiment)

[0040] <1. Overall Structure of the Incineration Equipment>

[0041] Figure 1 This is a diagram showing the overall structure of the combustion equipment 1 according to the first embodiment. The combustion equipment 1 is, for example, an incineration equipment that uses municipal waste, industrial waste, or biomass as the incinerated material G. Hereinafter, for ease of explanation, "incinerated material G" will be referred to as "waste G". The combustion equipment 1 is, for example, a grate furnace. However, the combustion equipment 1 is not limited to a grate furnace and may be other types of combustion equipment. In this embodiment, the combustion equipment 1 includes, for example, an incinerator 2, a waste heat recovery boiler 3, a desuperheating tower 4, a dust collection device 5, a flue 6, a chimney 7, and a control device 100.

[0042] Incinerator 2 is a furnace that burns waste G fed into hopper 11 (described later) while it is being transported. As the waste G burns in incinerator 2, waste gas is generated. This waste gas is then transported to waste heat recovery boiler 3 located at the top of incinerator 2. Waste heat recovery boiler 3 heats water by exchanging heat between the waste gas generated in incinerator 2 and water, thereby generating steam. The waste gas from waste heat recovery boiler 3 is cooled in cooling tower 4 and then transported to dust collection device 5. After soot or dust is removed in dust collection device 5, the waste gas is discharged into the atmosphere via flue 6 and chimney 7.

[0043] <2. Incinerator>

[0044] Next, the incinerator 2 will be described in detail. The incinerator 2 includes, for example, a supply mechanism 10, a furnace body 20, a grate 30, multiple air boxes 41, an exhaust trough 42, a furnace 43, and an air supply mechanism 50.

[0045] (Supply institutions)

[0046] The supply mechanism 10 is a mechanism that temporarily stores the waste G transported by a crane (not shown) and sequentially supplies the waste G toward the processing space V of the furnace body 20, which will be described later. The supply mechanism 10 includes, for example, a hopper 11 and a feeder 12.

[0047] The hopper 11 is a storage section provided for supplying waste G to the interior of the furnace body 20. Waste G, transported by a crane (not shown), is fed into the hopper 11. The hopper 11 has an inlet 11a for feeding waste G from the outside and an outlet 11b for guiding the supplied waste G into the processing space V within the furnace body 20, which will be described later.

[0048] A feeder 12 is provided at the outlet 11b of the hopper 11. The feeder 12 is plate-shaped and extends along the bottom of the outlet 11b of the hopper 11. The feeder 12 is driven by an extrusion device (not shown) to extrude the waste G accumulated inside the hopper 11 into the processing space V of the furnace body 20.

[0049] (Furnace body)

[0050] The furnace body 20 is a device that is arranged adjacent to the hopper 11 and simultaneously conveys and burns waste G. Hereinafter, the conveying direction of the waste G in the combustion device 1 will be referred to as the "conveying direction D". The furnace body 20 has, sequentially from upstream to downstream in the conveying direction D, a drying section 20a, a combustion section 20b, and a post-combustion section 20c. The drying section 20a is the area where the waste G supplied from the hopper 11 is dried before being burned on the grate 30. The combustion section 20b and the post-combustion section 20c are the areas where the waste G, dried in the drying section 20a, is burned on the grate 30. In the combustion section 20b, the thermal decomposition gases generated by the waste G cause diffusion combustion, thereby producing a flame F. In the post-combustion section 20c, since the fixed carbon following the diffusion combustion of the waste G burns, no flame F is produced. The combustion section 20b and the post-combustion section 20c are an example of a processing space V for burning waste G.

[0051] (grate)

[0052] The grate 30 includes multiple grates 31. These grates 31 form a grate surface 30a, which is the bottom surface of the furnace body 20 (e.g., the bottom surface of the processing space V). Waste G is supplied in layers to the grate surface 30a by the supply mechanism 10. The grate surface 30a is arranged to cover the aforementioned drying section 20a, combustion section 20b, and post-combustion section 20c. The multiple grates 31 include fixed grates and movable grates. The fixed grates are fixed to the upper surface of the bellows 41 (described later). The movable grates, by reciprocating at a constant speed along the conveying direction D, simultaneously mix and transport the waste G on the movable grates and the fixed grates (on the grate surface 30a) downstream.

[0053] (Bellphone)

[0054] The bellows 41 are located below the grate 30 and supply combustion air to the interior of the furnace body 20 via the grate 30. Multiple bellows 41 are arranged in the conveying direction D.

[0055] (Discharge tank)

[0056] The discharge chute 42 is a device that allows the waste G, which has been burned and turned into ash, to fall onto an ash pushing device located below the furnace body 20. The discharge chute 42 is located at the bottom of the furnace body 20.

[0057] (stove)

[0058] The furnace 43 extends upward from the upper part of the furnace body 20. The exhaust gas generated by burning waste G within the processing space V is transported to the waste heat recovery boiler 3 via the furnace 43. The exhaust gas is an example of "combustion gas." The furnace 43 is an example of a "flow path for the combustion gas." Details regarding the furnace 43 will be described later.

[0059] (Air supply unit)

[0060] The air supply mechanism 50 supplies air (e.g., combustion air) to the interior of the furnace body 20. The air supply mechanism 50 includes, for example, a blower 51, a primary air duct 52, an air preheater 53, a secondary air duct 54, and an air damper 55.

[0061] The blower 51 is a push-type blower that compresses air (e.g., combustion air) into the interior of the furnace body 20. The blower 51 includes, for example, a first blower 51A and a second blower 51B. The first blower 51A compresses combustion air into the interior of the furnace body 20 (e.g., the processing space V) via a primary air duct 52 and a bellows 41. The second blower 51B compresses combustion air into the interior of the furnace 43 via a secondary air duct 54.

[0062] The primary air duct 52 connects the first blower 51A to the air box 41. One or more primary air dampers 55A are provided along the primary air duct 52. The opening degree of the primary air dampers 55A changes the flow rate of combustion air flowing in the primary air duct 52. The air preheater 53 is a heat exchanger that preheats the air compressed from the first blower 51A. For example, the air preheater 53 is located along the primary air duct 52.

[0063] Secondary air duct 54 connects the second blower 51B to the furnace 43. Secondary air supplied to the furnace 43 flows from above the grate 30 toward the waste G. One or more secondary air dampers 55B are provided along the secondary air duct 54. The opening degree of the secondary air dampers 55B changes the flow rate of the combustion air flowing in the secondary air duct 54. In this embodiment, the primary air damper 55A and the secondary air damper 55B are collectively referred to as "damper 55".

[0064] <3. Waste Heat Recovery Boiler>

[0065] Next, the waste heat recovery boiler 3 will be described. The waste heat recovery boiler 3 includes, for example, a boiler body 61 and a pipe 62. The boiler body 61 is connected to the furnace 43 of the incinerator 2. Waste gas generated in the incinerator 2 flows into the interior of the boiler body 61. The pipe 62 extends inside the boiler body 61. Multiple superheaters and multiple desuperheaters are installed on the pipe 62. Water is supplied from the water supply section to the inlet of the pipe 62. At least a portion of the water flowing in the pipe 62 is heated inside the boiler body 61 through heat exchange to become main steam and flows toward external equipment (e.g., a turbine).

[0066] <4. Stove>

[0067] Next, the furnace 43 will be described in detail.

[0068] Figure 2 It is Figure 1 The image shows a magnified perspective view of the area enclosed by line F2. In this embodiment, the furnace 43 includes, for example, a furnace wall 70, a plurality of nozzles 80, and a temperature detection unit 90.

[0069] (Furnace wall)

[0070] The furnace wall 70 forms a flow path for exhaust gas in the furnace 43. The furnace wall 70 is, for example, formed into a cylindrical shape defined by a front wall 71, a rear wall 72, a left wall 73, and a right wall 74, and extends in the vertical direction. The furnace wall 70 is formed of refractory material.

[0071] (nozzle)

[0072] The multiple nozzles 80 are nozzles for injecting a denitrifying agent into the furnace 43. The denitrifying agent is, for example, ammonia gas, but it can also be ammonia water, urea gas, or urea water. The multiple nozzles 80 include multiple nozzles 81 (e.g., four nozzles 81A to 81D) included in the first group G1 and multiple nozzles 82 (e.g., four nozzles 82A to 82D) included in the second group G2. Hereinafter, nozzles 81A to 81D and nozzles 82A to 82D will not be distinguished and will be simply referred to as "nozzle 80".

[0073] The plurality of nozzles 81 included in group G1 are disposed in the furnace 43 at a first height H1. The first height H1 is, for example, a position 9 m above a certain reference plane (e.g., grate surface 30a). However, the first height H1 is not limited to the height of the specific example described above. Nozzles 81A and 81B are disposed on the left wall 73 of the furnace 43 and spray denitrifying agent into the furnace 43 from the left wall 73. On the other hand, nozzles 81C and 81D are disposed on the right wall 74 of the furnace 43 and spray denitrifying agent into the furnace 43 from the right wall 74.

[0074] Furthermore, from another perspective, when viewed from above, nozzles 81A and 81C are located in the front space FS, which is positioned forward of the center of the interior space of the furnace 43 (see reference). Figure 1 Correspondingly, nozzles 81B and 81D are configured to spray denitrifying agent into the forward space FS. On the other hand, when viewed from above, nozzles 81B and 81D are positioned relative to the rear space BS (see reference FS) in the interior space of the furnace 43, which is located further back than the center. Figure 1 Correspondingly configured, and denitrification agent is sprayed into the rear space BS.

[0075] The plurality of nozzles 82 included in group G2 are disposed in the furnace 43 at a second height H2, different from the first height H1. The second height H2 is, for example, a position 11m above the aforementioned reference plane. However, the second height H2 is not limited to the height of the specific example described above. Nozzles 82A and 82B are disposed on the left wall 73 of the furnace 43 and spray denitrifying agent into the furnace 43 from the left wall 73. On the other hand, nozzles 82C and 82D are disposed on the right wall 74 of the furnace 43 and spray denitrifying agent into the furnace 43 from the right wall 74.

[0076] Furthermore, from another perspective, when viewed from above, nozzles 82A and 82C are in relation to the front space FS within the interior space of the furnace 43 (see reference). Figure 1 Correspondingly configured, the nozzles 82B and 82D spray the denitrification agent into the forward space FS. On the other hand, when viewed from above, the nozzles 82B and 82D are positioned relative to the rear space BS within the interior space of the furnace 43 (see reference). Figure 1 Correspondingly configured, and denitrification agent is sprayed into the rear space BS.

[0077] However, the configuration and number of nozzles 80 are not limited to the examples described above. At least one nozzle 80 is sufficient. In this embodiment, nozzles 81A-81D and nozzles 82A-82D are examples of the "first nozzle".

[0078] (Temperature Detection Department)

[0079] The temperature detection unit 90 is a unit that detects the temperature (exhaust gas temperature) inside the furnace 43. The temperature detection unit 90 includes, for example, a first temperature detection unit 91 and a second temperature detection unit 92. The first temperature detection unit 91 is, for example, a temperature detector (e.g., a thermocouple) installed at a first height H1, and detects the exhaust gas temperature at the first height H1. The second temperature detection unit 92 is, for example, a temperature detector (e.g., a thermocouple) installed at a second height H2, and detects the exhaust gas temperature at the second height H2.

[0080] However, the configuration and number of the first temperature detection unit 91 and the second temperature detection unit 92 are not limited to the example described above. For example, the first temperature detection unit 91 and the second temperature detection unit 92 can be configured at heights different from the first height H1 and the second height H2. Furthermore, either the first temperature detection unit 91 or the second temperature detection unit 92 can be omitted. Moreover, the first temperature detection unit 91 and the second temperature detection unit 92 are not limited to thermocouples. The first temperature detection unit 91 and the second temperature detection unit 92 can be detection units capable of detecting exhaust gas temperature, or they can be infrared cameras, etc.

[0081] <5. Catalyst-free denitrification system>

[0082] In this embodiment, the combustion device 1 includes a catalyst-free denitrification system 200. The catalyst-free denitrification system 200 includes a denitrification agent supply unit 210 and a nozzle angle control unit 110 (described later). Figure 5 ).

[0083] The denitrification agent supply unit 210 includes, for example, the aforementioned nozzles 80, denitrification agent supply lines 211, and a press 212. The denitrification agent supply lines 211 are connected to each nozzle 80. The press 212 is connected to each nozzle 80 via the denitrification agent supply lines 211. The press 212 pressurizes denitrification agent to each nozzle 80 via the denitrification agent supply lines 211.

[0084] <6. Nozzle Structure>

[0085] Next, the structure of nozzle 80 will be described in detail.

[0086] Figure 3 and Figure 4This is a cross-sectional view of nozzle 80. In this embodiment, nozzle 80 has a structure capable of adjusting the denitrification agent injection angle relative to the exhaust gas flow direction. In this embodiment, the exhaust gas flow direction is a vertical direction from bottom to top. Nozzle 80 has a structure capable of adjusting the denitrification agent injection angle (i.e., the angle in the vertical direction) relative to the vertical direction. Nozzle 80 includes, for example, a tube portion 85, a stationary portion 86, a movable portion 87, and an adjustment mechanism 88.

[0087] (Management Department)

[0088] The pipe section 85 is fixed to the furnace wall 70 and receives denitrification agent from the denitrification agent supply line 211. The pipe section 85 is formed, for example, a straight pipe, extending in a straight line in the horizontal direction toward the interior of the furnace 43. The pipe section 85 passes, for example, through a hole 70h provided in the furnace wall 70.

[0089] (Stationary section)

[0090] The stationary part 86 is a part that supports the movable part 87 so that it can rotate. The stationary part 86 is disposed between the tube part 85 and the movable part 87, and is connected to the tube part 85.

[0091] The stationary part 86, for example, has a spherical or cylindrical shape. That is, when observing the cross-section along the vertical direction ( Figure 3 When viewed in the cross-section shown, the stationary portion 86 has an external shape comprising a first arc portion 86a and a second arc portion 86b. The first arc portion 86a is located at the lower end of the stationary portion 86 and is an arc portion that protrudes downwards. The second arc portion 86b is located at the upper end of the stationary portion 86 and is an arc portion that protrudes upwards.

[0092] The stationary section 86 has an internal space. The interior of the stationary section 86 is in communication with the interior of the pipe section 85, and the denitrification agent flows into the interior of the stationary section 86 through the pipe section 85. The stationary section 86 has an opening 86h to allow the denitrification agent flowing into the interior of the stationary section 86 to pass to the movable section 87.

[0093] (Moveable parts)

[0094] The movable part 87 is rotatably connected to the stationary part 86 and is capable of spraying the denitrifying agent to the outside. The movable part 87 is disposed at the front end of the nozzle 80, facing the interior of the furnace 43. The movable part 87 is rotatably connected to the stationary part 86, for example, via a horizontally rotating shaft 87j. The movable part 87 is capable of rotating obliquely upward and obliquely downward relative to the stationary part 86.

[0095] The movable part 87, for example, has a spherical or cylindrical shape along the outer (or inner) surface of the stationary part 86. That is, when observing a cross-section along the vertical direction... Figure 3When viewed in the cross-section shown, the movable part 87 includes a third arcuate portion 87a and a fourth arcuate portion 87b. The third arcuate portion 87a is located at the lower end of the movable part 87 and is an arcuate portion protruding downwards. The fourth arcuate portion 87b is located at the upper end of the movable part 87 and is an arcuate portion protruding upwards. In this embodiment, the third arcuate portion 87a of the movable part 87 slides along the first arcuate portion 86a of the stationary portion 86, and the fourth arcuate portion 87b of the movable part 87 slides along the second arcuate portion 86b of the stationary portion 86, thereby allowing the movable part 87 to rotate obliquely upwards and downwards relative to the stationary portion 86. According to this structure, the connection between the stationary portion 86 and the movable part 87 is sealed in a surface shape, thereby suppressing leakage of the denitrifying agent from the connection between the stationary portion 86 and the movable part 87.

[0096] The movable part 87 has an internal space. The interior of the movable part 87 is connected to the interior of the stationary part 86, and the denitrification agent flowing through the stationary part 86 flows into the interior of the movable part 87. The movable part 87 has a spray port 87h to spray the denitrification agent flowing into the interior of the movable part 87 toward the interior of the furnace 43 (i.e. toward the exhaust gas).

[0097] (Adjustment of the organization)

[0098] The adjustment mechanism 88 is a mechanism capable of adjusting the angle (i.e., rotational position) of the movable part 87 relative to the stationary part 86. The adjustment mechanism 88 may include, for example, a first cable 88a, a second cable 88b, a first traction part 88c, and a second traction part 88d.

[0099] The first cable 88a is connected to the third arc portion 87a of the movable part 87. The first cable 88a passes through, for example, the gap between the outer peripheral surface of the tube portion 85 and the inner peripheral surface of the hole portion 70h of the furnace wall 70 and extends to the outside of the furnace wall 70.

[0100] The second cable 88b is connected to the fourth arc portion 87b of the movable part 87. The second cable 88b passes, for example, through the gap between the outer peripheral surface of the tube portion 85 and the inner peripheral surface of the hole portion 70h of the furnace wall 70 and extends to the outside of the furnace wall 70.

[0101] The first traction unit 88c is connected to the first cable 88a. The first traction unit 88c includes, for example, a drive device such as a motor. In a standby state where no predetermined control command is received from the control device 100, the first traction unit 88c releases the hold on the first cable 88a. On the other hand, when the first traction unit 88c receives a predetermined control command from the control device 100, it pulls the first cable 88a toward the outside of the furnace wall 70. As a result, the movable part 87 rotates downward relative to the stationary part 86. Consequently, the injection direction of the denitrification agent is directed diagonally downward (see reference). Figure 4 ).

[0102] Here, the hole 70h in the furnace wall 70 has an enlarged diameter portion 70ha (e.g., a chamfered portion) that expands the internal space of the hole 70h within the rotation range of the movable portion 87. Thus, even when the movable portion 87 rotates, it is possible to prevent the movable portion 87 from contacting the furnace wall 70.

[0103] The second traction unit 88d is connected to the second cable 88b. The second traction unit 88d includes, for example, a drive device such as a motor. In a standby state where no predetermined control command is received from the control device 100, the second traction unit 88d releases the second cable 88b. On the other hand, when the second traction unit 88d receives a predetermined control command from the control device 100, it pulls the second cable 88b towards the outside of the furnace wall 70. As a result, the movable part 87 rotates upward relative to the stationary part 86. Consequently, the injection direction of the denitrification agent is directed obliquely upward.

[0104] In this embodiment, an example of an extended nozzle 300 is formed by a stationary part 86, a movable part 87, and an adjustment mechanism 88. The extended nozzle 300 is, for example, a functional component that adds a nozzle 80 capable of adjusting the injection angle of the denitrifying agent to an existing combustion device that is provided with a straight-tube-shaped denitrifying agent injection nozzle. For example, the tube part 85 is the original nozzle provided in the original combustion device. The extended nozzle 300 provides a nozzle 80 capable of adjusting the injection angle of the denitrifying agent by connecting to the original nozzle, i.e., the tube part 85.

[0105] <7. Control Device>

[0106] Next, the control device 100 will be described.

[0107] The control device 100 centrally controls the combustion equipment 1. For example, the control device 100 controls the combustion of waste G in the processing space V of the furnace body 20. The control device 100 is an example of a "control unit".

[0108] Figure 5 This is a block diagram showing the functional structure related to denitrification. The control device 100 includes, for example, a nozzle angle control unit 110. The nozzle angle control unit 110 controls the injection angle of the nozzle 80 based on information related to the exhaust gas temperature.

[0109] In this embodiment, the nozzle angle control unit 110 controls the spray angle of the plurality of nozzles 80 based on the detection results of the temperature detection unit 90. For example, the nozzle angle control unit 110 controls the spray angle of nozzles 81A to 81D included in the first group G1 based on the detection results of the first temperature detection unit 91. On the other hand, the nozzle angle control unit 110 controls the spray angle of nozzles 82A to 82D included in the second group G2 based on the detection results of the second temperature detection unit 92.

[0110] Furthermore, the following provides a detailed explanation of how the spray angles of nozzles 81A to 81D included in the first group G1 are controlled based on the detection results of the first temperature detection unit 91. Regarding the control of the spray angles of nozzles 82A to 82D included in the second group G2 based on the detection results of the second temperature detection unit 92, in the following description, "first temperature detection unit 91" can be replaced with "second temperature detection unit 92", "first group G1" can be replaced with "second group G2", and "nozzles 81A to 81D" can be replaced with "nozzles 82A to 82D".

[0111] Figure 6 This is a graph showing the relationship between reaction temperature (exhaust gas temperature) and denitrification rate. Here, the catalystless denitrification reaction process using ammonia (or urea) as a reducing agent is roughly divided into (1) NOx removal based on reduction reaction (main reaction) and (2) NOx generation based on oxidation reaction (side reaction).

[0112] like Figure 6 As shown, the denitrification rate reaches its maximum at a reaction temperature, for example, around 950°C. Above a certain temperature range (hereinafter referred to as the "specified temperature range TR"), the denitrification rate decreases, and below the specified temperature range TR, the denitrification rate also decreases. This is because when the reaction temperature is too low, the main reaction is difficult to proceed, and when it is too high, the side reactions will counteract the main reaction. Therefore, to improve the denitrification rate, it is preferable to inject the denitrification agent into the exhaust gas within the specified temperature range TR.

[0113] Figure 7 This is a diagram used to illustrate the control of the injection angle. In this embodiment, when the temperature (exhaust gas temperature) detected by the first temperature detection unit 91 is within the specified temperature range TR, the nozzle angle control unit 110 adjusts the injection angle of the nozzle 80 to 0 degrees and injects the denitrification agent horizontally.

[0114] When the temperature detected by the first temperature detection unit 91 is lower than the predetermined temperature range TR, the nozzle angle control unit 110 controls the adjustment mechanism 88 to rotate the movable part 87 downward relative to the stationary part 86, thereby controlling the injection angle of the nozzle 80 so that the injection direction of the denitrification agent is obliquely downward. Thus, the injection angle of the nozzle 80 is adjusted to allow the denitrification agent to be injected upstream of the exhaust gas flow direction. For example, when the temperature detected by the first temperature detection unit 91 is lower than the predetermined temperature range TR, the nozzle angle control unit 110 adjusts the injection angle of the nozzle 80 so that the lower the temperature detected by the first temperature detection unit 91, the further downward the injection direction of the denitrification agent.

[0115] In this embodiment, the spray angle of the nozzle 80 is adjusted based on the difference between the temperature detected by the first temperature detection unit 91 and the lower limit of a predetermined temperature range T. For example, when the temperature detected by the first temperature detection unit 91 is lower than the predetermined temperature range TR, the spray angle of the nozzle 80 is adjusted within an angle range of 0 degrees to -45 degrees. Furthermore, "adjusting the spray angle based on the difference between the detected temperature and the lower limit of the predetermined temperature range T" is not limited to... Figure 7 As shown, the injection angle is adjusted in a linear proportion to the magnitude of the difference, and the same applies to the case where the injection angle is adjusted in stages (e.g., in a step-like manner of 1 or 2 segments) according to the magnitude of the difference.

[0116] When the temperature detected by the first temperature detection unit 91 is higher than the predetermined temperature range TR, the nozzle angle control unit 110 controls the adjustment mechanism 88 to rotate the movable part 87 upward relative to the stationary part 86, thereby controlling the spray angle of the nozzle 80 so that the spray direction of the denitrifying agent is obliquely upward. Thus, the spray angle of the nozzle 80 is adjusted to spray the denitrifying agent downstream of the exhaust gas flow direction. For example, when the temperature detected by the first temperature detection unit 91 is higher than the predetermined temperature range TR, the nozzle angle control unit 110 adjusts the spray angle of the nozzle 80 so that the higher the temperature detected by the first temperature detection unit 91, the more upward the spray direction of the denitrifying agent.

[0117] In this embodiment, the spray angle of the nozzle 80 is adjusted based on the difference between the temperature detected by the first temperature detection unit 91 and the upper limit of a predetermined temperature range T. For example, when the temperature detected by the first temperature detection unit 91 is higher than the predetermined temperature range TR, the spray angle of the nozzle 80 is adjusted within an angle range of 0 degrees to +45 degrees. Furthermore, "adjusting the spray angle based on the difference between the detected temperature and the upper limit of the predetermined temperature range T" is not limited to... Figure 7 The same applies to adjusting the injection angle in a linear proportion to the magnitude of the difference, as shown above, and adjusting the injection angle in stages (e.g., in a stepped manner of 1 or 2 stages) according to the magnitude of the difference.

[0118] The aforementioned specified temperature range TR is an example of a "specified reference". Furthermore, a "specified reference" is not limited to a specific temperature range; it can also be a specified temperature value (e.g., 950°C). That is, the "specified temperature range TR" in this description can be appropriately replaced with "specified temperature".

[0119] The above describes how the injection angles of nozzles 81A to 81D included in the first group G1 are controlled based on the detection results of the first temperature detection unit 91. This control is performed separately for nozzles 81A to 81D included in the first group G1 and nozzles 82A to 82D included in the second group G2. Therefore, for example, when the temperature detected by the first temperature detection unit 91 is higher than the specified temperature range TR but the temperature detected by the second temperature detection unit 92 is lower than the specified temperature range TR, the injection angles of nozzles 81A to 81D included in the first group G1 are adjusted so that the injection direction of the denitrifying agent is obliquely upward, and the injection angles of nozzles 82A to 82D included in the second group G2 are adjusted so that the injection direction of the denitrifying agent is obliquely downward.

[0120] <8. Control Flow>

[0121] Next, the control process will be explained.

[0122] Figure 8 This is a flowchart illustrating the control process related to the adjustment of the injection angle of the nozzles 81A to 81D included in the first group G1. First, the exhaust gas temperature at the first height H1 is detected by the first temperature detection unit 91 (S101).

[0123] Next, the nozzle angle control unit 110 determines whether the temperature detected by the first temperature detection unit 91 is within the specified temperature range TR (S102). When the temperature detected by the first temperature detection unit 91 is within the specified temperature range TR (S102: Yes), the nozzle angle control unit 110 adjusts the spray angle of the nozzle 80 to horizontal (S103) and ends a series of processes.

[0124] On the other hand, when the temperature detected by the first temperature detection unit 91 is not within the specified temperature range TR (S102: No), the nozzle angle control unit 110 determines whether the temperature detected by the first temperature detection unit 91 is higher than the specified temperature range TR (S104).

[0125] When the temperature detected by the first temperature detection unit 91 is higher than the specified temperature range TR (S104: Yes), the nozzle angle control unit 110 adjusts the spray angle of the nozzle 80 obliquely upward according to the temperature detected by the first temperature detection unit 91 (S105), and ends a series of processes.

[0126] On the other hand, when the temperature detected by the first temperature detection unit 91 is lower than the specified temperature range TR (S104: No), the nozzle angle control unit 110 adjusts the spray angle of the nozzle 80 diagonally downward according to the temperature detected by the first temperature detection unit 91 (S106), and ends a series of processes.

[0127] The processes described above, S101 to S106, are repeated at a specified cycle.

[0128] <9. Effects>

[0129] In combustion equipment, there is a problem that the denitrification rate decreases when the exhaust gas temperature changes. To address this problem, as a comparative example, a structure is considered that arranges multiple nozzles along the vertical height and selects a nozzle at a preferred height to spray denitrification agent. In this comparative example structure, the construction of multiple nozzles is cumbersome, and boiler tubes are often installed on the wall near the denitrification nozzles. With the installation of multiple nozzles, a large amount of bending processing of the boiler tubes is required, thus making construction difficult.

[0130] Furthermore, in the structure of the comparative example described above, multiple nozzles for injecting denitrification agent are required. Even when the nozzles are not in use, a small amount of gas needs to be continuously supplied to prevent clogging. Therefore, the more nozzles there are, the more common gas (gas such as steam or recirculated gas used to dilute the denitrification agent) is required, and equipment such as the pressurizer also needs to be large.

[0131] On the other hand, the catalystless denitrification system 200 of this embodiment includes: a denitrification agent supply unit 210, including a nozzle 80 disposed on a furnace 43 through which exhaust gas flows and whose denitrification agent injection angle relative to the flow direction of exhaust gas can be adjusted; and a nozzle angle control unit 110, which controls the injection angle of the nozzle 80 based on information related to the exhaust gas temperature. With this structure, by changing the injection angle of the nozzle 80, the denitrification agent can be introduced in a manner that allows it to react at a temperature close to the target temperature (e.g., the aforementioned specified temperature range TR). Therefore, even without providing multiple nozzles along the height direction, it is possible to cope with temperature fluctuations within the furnace. Furthermore, with the structure of this embodiment, the required number of nozzles 80 is reduced, thus reducing the amount of gas introduced when the nozzles are not in use. Therefore, miniaturization of the equipment is possible.

[0132] In the catalyst-free denitrification process of combustion equipment such as waste incinerators 1, at the denitrification agent injection point, the combustion gas flows vertically upwards, with the temperature of the combustion gas decreasing towards the top and increasing towards the bottom. Therefore, by injecting the denitrification agent at an upward angle when the temperature at the denitrification agent injection point is higher than the target temperature and at a downward angle when the temperature at the denitrification agent injection point is lower than the target temperature, a high denitrification rate can be maintained even under significant fluctuations in operating conditions.

[0133] Figure 9 This diagram illustrates the effect of adjusting the spray angle of nozzle 80, and it shows a simulation result comparing the case where the spray angle of nozzle 80 is adjusted with the case where it is not adjusted. Figure 9As shown, it can be seen that when the spray angle of nozzle 80 is adjusted, the denitrification rate is improved compared with the case where the spray angle of nozzle 80 is not adjusted.

[0134] For example, in Figure 9 In the example shown, the denitrification agent is sprayed from two different height positions. Under average operating conditions, the temperature near the lower side (first height H1) is close to the target temperature, while the temperature near the upper side (second height H2) is lower than the target temperature. In the comparative example structure where the denitrification agent is always sprayed horizontally, denitrification at the upper side (second height H2) is difficult to progress, thus making it difficult to reduce NOx. In contrast, by adjusting the spray angle of the upper nozzle 80 downward as in this embodiment to bring the reaction temperature at the upper side (second height H2) closer to the target temperature, denitrification progresses, thereby reducing NOx.

[0135] <10. Variations>

[0136] Hereinafter, a variation of the first embodiment will be described.

[0137] Figure 10 This is a cross-sectional view of the nozzle 80 in a modified example. In this modified example, the furnace 43 has a protective device 410 for protecting the nozzle 80. The protective device 410 includes a bellows 411, an air supply pipe 412, and a blower 413.

[0138] The bellows 411 is inserted into the hole 70h provided in the furnace wall 70. The bellows 411 is made of metal and accommodates at least a portion of the nozzle 80. For example, the bellows 411 accommodates the connection (rotation part) between the stationary part 86 and the movable part 87 of the nozzle 80. The bellows 411 has an exhaust port 411h for discharging air supplied to the interior of the bellows 411 via the air supply pipe 412 (described later) into the interior of the furnace 43.

[0139] Air supply pipe 412 is internally connected to air box 411. Blower 413 is internally connected to air box 411 via air supply pipe 412. Blower 413 pressurizes air into air box 411 via air supply pipe 412. By pressurizing air into air box 411 via air supply pipe 412, backflow of exhaust gas from furnace 43 into air box 411 can be prevented. This protects the components housed in air box 411 from high temperatures and dust contained in exhaust gas. For example, this prevents the connection (rotating part) between the stationary part 86 and the movable part 87 of nozzle 80 from becoming fixed.

[0140] In this modified example, the adjustment mechanism 88 includes, for example, a drive device 421 and a power transmission mechanism 422. The drive device 421 is, for example, a motor. The power transmission mechanism 422 is a mechanism that transmits power, such as a linkage or gear, and connects the drive device 421 to the movable part 87 of the nozzle 80. Thus, the nozzle angle control unit 110 can rotate the movable part 87 relative to the stationary part 86 by driving the drive device 421. In this modified example, the power transmission mechanism 422 is housed within the bellows 411 and is protected thereunder.

[0141] Based on this structure, a denitrification agent supply unit 210 can be provided that can be used more stably even in environments where it comes into contact with combustion gases at high temperatures and high dust concentrations.

[0142] (Second Implementation)

[0143] Next, the second embodiment will be described. In the second embodiment, when the flow rates of the exhaust gas in the front space FS and the rear space BS of the furnace 43 are different, the supply ratio (e.g., the distribution ratio) of the denitrification agent before and after the furnace 43 is changed, which differs from the first embodiment. Furthermore, the structure, except for the content described below, is the same as in the first embodiment.

[0144] Specifically, the exhaust gas flow rates in the front space FS and rear space BS of furnace 43 sometimes differ. For example, when... Figure 1 When a flow path bends downwards on the downstream side of the furnace 43, as shown, the flow velocity is low at the front of the furnace 43, while the flow velocity tends to increase at the rear. In this case, less denitrification agent is required in the region with low flow velocity at the front of the furnace. On the other hand, more denitrification agent is required in the region with high flow velocity at the rear of the furnace.

[0145] Here, since more active combustion produces more combustion gases, it is assumed that the temperature tends to rise in areas with higher flow rates. In this embodiment, this situation is utilized to calculate the flow rate distribution on the front / rear side of the furnace based on information about the furnace temperature distribution (temperature difference between the front and rear sides of the furnace), and to allocate the amount of denitrification agent added in a manner proportional to the flow rates at the front and rear of the furnace.

[0146] (nozzle)

[0147] Figure 11 This is a perspective view showing the furnace 43 of this embodiment. Figure 11 To facilitate viewing the accompanying drawings, the diagrams of the denitrification agent supply pipeline 211 and the press 212, etc., have been omitted.

[0148] In this embodiment, denitrifying agent flowing in a denitrifying agent supply line 211 is distributed and supplied to nozzles 81A to 81D. Similarly, denitrifying agent flowing in a denitrifying agent supply line 211 is distributed and supplied to nozzles 82A to 81D. In this embodiment, nozzles 81A, 81C, 82A, and 82C are each nozzle 80 disposed corresponding to the front space FS (the front region FR described later), and are examples of "first nozzles". On the other hand, nozzles 81B, 81D, 82B, and 82D are each nozzle 80 disposed corresponding to the rear space BS (the rear region BR described later), and are examples of "second nozzles".

[0149] (Temperature Detection Department)

[0150] In this embodiment, the furnace 43 includes a front region FR and a rear region BR in a cross-section (e.g., a horizontal cross-section) along a direction intersecting the flow direction of the exhaust gas. Viewed from above, the front region FR is the region overlapping with the front space FS. The front region FR is an example of a "first region". Viewed from above, the rear region BR is the region overlapping with the rear space BS. The rear region BR is an example of a "second region".

[0151] The first temperature detection unit 91 includes multiple (e.g., two) temperature detectors 91A and 91B (front temperature detector 91A and rear temperature detector 91B) disposed at a first height H1. Temperature detectors 91A and 91B are, for example, thermocouples, and detect the exhaust gas temperature at the first height H1. The front temperature detector 91A is configured corresponding to the front region FR and detects the exhaust gas temperature related to the front region FR. The rear temperature detector 91B is configured corresponding to the rear region BR and detects the exhaust gas temperature related to the rear region BR.

[0152] The second temperature detection unit 92 includes multiple (e.g., two) temperature detectors 92A and 92B (front temperature detector 92A and rear temperature detector 92B) disposed at the second height H2. Temperature detectors 92A and 92B are, for example, thermocouples, and detect the exhaust gas temperature at the second height H2. The front temperature detector 92A is configured corresponding to the front region FR and detects the exhaust gas temperature related to the front region FR. The rear temperature detector 92B is configured corresponding to the rear region BR and detects the exhaust gas temperature related to the rear region BR.

[0153] Figure 12 This is a diagram illustrating another embodiment of the temperature detection unit 90. The temperature detection unit 90 in this alternative embodiment includes a third temperature detection unit 94 comprising a camera 94a mounted on the top of the furnace 43. The camera 94a is, for example, an infrared camera, which captures an infrared image of the interior of the furnace 43 from above.

[0154] Figure 13 This diagram illustrates an infrared image IM captured by camera 94a. The infrared image IM includes a front region FR corresponding to the front space FS of the furnace 43 and a rear region BR corresponding to the rear space BS of the furnace 43. The third temperature detection unit 94 calculates the temperature (e.g., average temperature) of the front region FR and the temperature (e.g., average temperature) of the rear region BR based on the brightness values ​​contained in the front region FR and the rear region BR in the infrared image IM. Additionally, it can be set... Figure 12 and Figure 13 The temperature detection unit 90 described above is used instead of the temperature detection unit 90 described above. Figure 11 The temperature detection unit 90 shown, or except Figure 11 In addition to the temperature detection unit 90 shown, 12 and 12 are also provided. Figure 13 The temperature detection unit 90 of the other embodiment shown above.

[0155] (Denitrification Agent Supply Department)

[0156] Figure 14 This is a block diagram showing the functional structure related to denitrification in the second embodiment. In this embodiment, the denitrification agent supply line 211 of the denitrification agent supply unit 210 has a first front nozzle flow rate adjustment unit 231, a first rear nozzle flow rate adjustment unit 232, a second front nozzle flow rate adjustment unit 233, and a second rear nozzle flow rate adjustment unit 234.

[0157] The first front nozzle flow rate adjustment unit 231 is an adjustment unit for adjusting the flow rate of the denitrifying agent supplied to the nozzles 81A and 81C included in the first group G1, and is, for example, a throttle valve. The first rear nozzle flow rate adjustment unit 232 is an adjustment unit for adjusting the flow rate of the denitrifying agent supplied to the nozzles 81B and 81D included in the first group G1, and is, for example, a throttle valve.

[0158] The second front nozzle flow rate adjustment unit 233 is an adjustment unit for adjusting the flow rate of the denitrifying agent supplied to nozzles 82A and 82C included in the second group G2, and is, for example, a throttle valve. The second rear nozzle flow rate adjustment unit 234 is an adjustment unit for adjusting the flow rate of the denitrifying agent supplied to nozzles 82B and 82D included in the second group G2, and is, for example, a throttle valve.

[0159] (Pre- and post-supply adjustment department)

[0160] In this embodiment, the control device 100 includes a front and rear supply adjustment unit 120. The front and rear supply adjustment unit 120 determines the supply ratio (e.g., distribution ratio) of the denitrifying agent before and after the furnace 43 based on the temperature difference detected by two temperature detectors 91A and 91B located at the same height (first height H1). For example, when there is a temperature difference detected by the two temperature detectors 91A and 91B, the front and rear supply adjustment unit 120 changes the supply ratio of the amount of denitrifying agent injected from nozzles 81A and 81C into the front space FS of the furnace 43 to the amount of denitrifying agent injected from nozzles 81B and 81D into the rear space BS of the furnace 43 by controlling at least one of the first front nozzle flow adjustment unit 231 and the first rear nozzle flow adjustment unit 232.

[0161] For example, when the temperature detected by the front temperature detector 91A is higher than the temperature detected by the rear temperature detector 91B, the front and rear supply adjustment unit 120 determines the supply ratio of the denitrifying agent before and after the furnace 43 so that the amount of denitrifying agent injected into the front space FS is greater than the amount of denitrifying agent injected into the rear space BS. On the other hand, when the temperature detected by the rear temperature detector 91B is higher than the temperature detected by the front temperature detector 91A, the front and rear supply adjustment unit 120 determines the supply ratio of the denitrifying agent before and after the furnace 43 so that the amount of denitrifying agent injected into the rear space BS is greater than the amount of denitrifying agent injected into the front space FS.

[0162] Furthermore, the following provides a detailed explanation of how the injection volume of nozzles 81A to 81D included in the first group G1 is controlled based on the detection results of the front temperature detector 91A and the rear temperature detector 91B of the first temperature detection unit 91. Regarding the control of the injection volume of nozzles 82A to 82D included in the second group G2 based on the detection results of the front temperature detector 92A and the rear temperature detector 92B of the second temperature detection unit 92, the following description can be replaced with "first temperature detection unit 91" as "second temperature detection unit 92", "front temperature detector 91A" as "front temperature detector 92A", "rear temperature detector 91B" as "rear temperature detector 92B", "first front nozzle flow adjustment unit 231" as "second front nozzle flow adjustment unit 233", "first rear nozzle flow adjustment unit 232" as "second rear nozzle flow adjustment unit 234", "first group G1" as "second group G2", and "nozzles 81A to 81D" as "nozzles 82A to 82D".

[0163] Figure 15This is a diagram used to illustrate the control of the injection volume. In this embodiment, when the temperature difference obtained by subtracting the temperature detected by the front temperature detector 91A from the temperature detected by the rear temperature detector 91B is within a specified temperature difference range TDR, the front and rear supply volume adjustment unit 120 sets the injection volume of the denitrifying agent injected from nozzles 81A and 81C into the front space FS of the furnace 43 to be the same as the injection volume of the denitrifying agent injected from nozzles 81B and 81D into the rear space FS of the furnace 43.

[0164] When the temperature difference exceeds the specified temperature difference range TDR, the front and rear supply adjustment unit 120 increases the opening of the throttle valve of the first rear nozzle flow adjustment unit 232 and decreases the opening of the throttle valve of the first front nozzle flow adjustment unit 231, so that the amount of denitrifying agent injected from nozzles 81B and 81D into the rear space BS of the furnace 43 is greater than the amount of denitrifying agent injected from nozzles 81A and 81C into the front space FS of the furnace 43. For example, when the temperature difference exceeds the specified temperature difference range TDR, the front and rear supply adjustment unit 120 determines the supply ratio such that the greater the temperature difference, the greater the difference in the supply ratio of denitrifying agent before and after the furnace 43.

[0165] For example, when the aforementioned temperature difference exceeds the specified temperature difference range TDR, the supply ratio of the denitrification agent before and after the furnace 43 is determined based on the magnitude of the difference between the aforementioned temperature difference and the upper limit of the specified temperature difference range TDR. Furthermore, "determining based on the magnitude of the difference between the aforementioned temperature difference and the upper limit of the specified temperature difference range TDR" is not limited to situations such as... Figure 15 The situation where the supply ratio is adjusted in a linear proportion to the size of the difference, as shown, also corresponds to the situation where the supply ratio is adjusted in stages (e.g., in a step-like manner of 1 or 2 segments) according to the size of the difference.

[0166] When the temperature difference is less than the specified temperature difference range TDR, the front and rear supply adjustment unit 120 increases the opening of the throttle valve of the first front nozzle flow adjustment unit 231 and decreases the opening of the throttle valve of the first rear nozzle flow adjustment unit 232, so that the amount of denitrifying agent injected from nozzles 81A and 81C into the front space FS of the furnace 43 is greater than the amount of denitrifying agent injected from nozzles 81B and 81D into the rear space BS of the furnace 43. For example, when the temperature difference is less than the specified temperature difference range TDR, the front and rear supply adjustment unit 120 determines the supply ratio such that the larger the absolute value of the temperature difference, the greater the difference in the supply ratio of denitrifying agent before and after the furnace 43.

[0167] For example, when the aforementioned temperature difference is less than the specified temperature difference range TDR, the supply ratio of the denitrification agent before and after the furnace 43 is determined based on the magnitude of the difference between the aforementioned temperature difference and the lower limit of the specified temperature difference range TDR. Furthermore, "determining based on the magnitude of the difference between the aforementioned temperature difference and the lower limit of the specified temperature difference range TDR" is not limited to situations such as... Figure 15 The situation where the supply ratio is adjusted in a linear proportion to the size of the difference, as shown, also corresponds to the situation where the supply ratio is adjusted in stages (e.g., in a step-like manner of 1 or 2 segments) according to the size of the difference.

[0168] The above describes how the injection volume of nozzles 81A to 81D included in group G1 is controlled based on the detection results of the front temperature detector 91A and the rear temperature detector 91B. This control is performed separately for nozzles 81A to 81D included in group G1 and nozzles 82A to 82D included in group G2. That is, the injection volume of nozzles 82A to 82D included in group G2 is controlled based on the detection results of the front temperature detector 92A and the rear temperature detector 92B.

[0169] The aforementioned specified temperature difference range TDR is an example of a "specified reference" in another perspective. Furthermore, the "specified reference" is not limited to a specific temperature difference range; the temperature difference can also be zero. That is, the "specified temperature range TR" in the description of this invention can be appropriately replaced with "temperature difference is zero".

[0170] Furthermore, in this embodiment, in order to reflect the difference in exhaust gas flow between the front region FR and the rear region BR of the furnace 43, the temperature detection results related to the front region FR and the rear region BR are directly used to control the amount of denitrifying agent injected. Alternatively, the front and rear supply adjustment unit 120 can also calculate the difference in exhaust gas flow between the front region FR and the rear region BR of the furnace 43 (flow distribution) based on the detection results of the front temperature detector 92A and the rear temperature detector 92B, and control the amount of denitrifying agent injected based on the calculated difference in exhaust gas flow.

[0171] (Control process)

[0172] Next, the control process will be explained.

[0173] Figure 16 This is a flowchart showing the control process related to the adjustment of the injection volume of nozzles 81A to 81D included in the first group G1. First, the temperature of the exhaust gas at the first height H1 is detected by the front temperature detector 91A and the rear temperature detector 91B of the first temperature detection unit 91 (S201).

[0174] Next, the front and rear supply adjustment unit 120 calculates the temperature difference between the front and rear of the furnace 43 by subtracting the temperature detected by the front temperature detector 91A from the temperature detected by the rear temperature detector 91B (S202).

[0175] Next, the front and rear supply adjustment unit 120 determines whether the calculated temperature difference is within the specified temperature difference range TDR (S203). When the temperature difference is within the specified temperature difference range TDR (S203: Yes), the front and rear supply adjustment unit 120 adjusts the injection amount of the denitrification agent injected into the front space FS of the furnace 43 to be the same as the injection amount of the denitrification agent injected into the rear space FS of the furnace 43 (S204), and ends the series of processes.

[0176] On the other hand, when the temperature difference is not within the specified temperature difference range TDR (S203: No), the front and rear supply adjustment unit 120 determines whether the temperature difference is greater than the specified temperature difference range TDR (S205).

[0177] When the temperature difference is greater than the specified temperature range TR (S205: Yes), the front and rear supply adjustment unit 120 reduces the amount of denitrifying agent injected into the front space FS of the furnace 43 and increases the amount of denitrifying agent injected into the rear space FS of the furnace 43 (S206), and ends a series of processes.

[0178] On the other hand, when the temperature difference is less than the specified temperature range TR (S204: No), the front and rear supply adjustment unit 120 increases the amount of denitrifying agent injected into the front space FS of the furnace 43 and decreases the amount of denitrifying agent injected into the rear space FS of the furnace 43 (S207), and ends a series of processes.

[0179] The processes described above, S201 to S207, are repeated at a specified cycle.

[0180] (Effects)

[0181] As mentioned above, the flow of combustion gases in combustion equipment often favors either the front or rear side of the furnace, depending on the combustion state and air injection conditions. It is generally assumed that the side with the faster flow rate has a larger exhaust gas volume and requires a larger amount of denitrification agent, while the side with the slower flow rate requires a smaller amount. Therefore, by injecting more denitrification agent onto the side with the larger exhaust gas volume at the same horizontal level, the concentration ratio of NOx and denitrification agent in the furnace can be made more uniform, thereby improving the denitrification rate.

[0182] Figure 17 This diagram illustrates the effect of adjusting the denitrification agent supply ratio before and after adjusting furnace 43. It compares the simulation results of adjusting the supply ratio with not adjusting it. Figure 17 As shown, it can be seen that when the supply ratio of denitrifying agent before and after the furnace 43 is adjusted, the denitrification rate is improved compared with the case where the distribution ratio is not adjusted.

[0183] (Other implementation methods)

[0184] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments and may include design changes that do not depart from the spirit of the present invention. For example, multiple nozzles 80 may be disposed on the front wall 71 instead of the left wall 73 and the right wall 74. The "information related to the temperature of the combustion gas" in the present invention is not limited to the detection results of thermocouples, but may also be information detected by cameras or other detection mechanisms.

[0185] Figure 18 This is a hardware structure diagram showing the structure of the computer 1100 according to this embodiment. The computer 1100 includes, for example, a processor 1110, a main memory 1120, a storage device 1130, and an interface 1140.

[0186] Each functional unit of the aforementioned control device 100 is installed in the computer 1100. Furthermore, the operations of each functional unit are stored in the storage device 1130 in the form of a program. The processor 1110 reads the program from the storage device 1130, expands it in the main memory 1120, and executes the aforementioned processing according to the program. Furthermore, the processor 1110 secures the storage area used by each functional unit in the main memory 1120 according to the program.

[0187] The program can be used to implement a portion of the functions that enable the computer 1100 to perform. For example, the program can function by combining with other programs stored in the storage device 1130 or with other programs installed in other devices. Furthermore, in addition to or instead of the above-described structure, the computer 1100 may also possess a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device). 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, some or all of the functions implemented by the processor 1110 can be implemented through this integrated circuit.

[0188] Examples of storage devices 1130 include magnetic disks, optical disks, and semiconductor memories. Storage device 1130 can be an internal medium directly connected to the bus of computer 1100, or an external medium connected to computer 1100 via interface 1140 or a communication line. Furthermore, when the program is published to computer 1100 via the communication line, the receiving computer 1100 can expand the program to main memory 1120 to execute the aforementioned processing. The program can also be used to implement a portion of the aforementioned functions. Additionally, the program can also be a so-called differential file (differential program) that implements the aforementioned functions by combining it with other programs already stored in storage device 1130.

[0189] <Postscript>

[0190] The catalystless denitrification system, combustion equipment, denitrification method, and extended nozzle described in each embodiment are understood as follows.

[0191] (1) The catalystless denitrification system 200 of the first method includes: a denitrification agent supply unit 210, including a first nozzle (e.g., nozzle 80) disposed in a flow path (e.g., furnace 43) in the combustion device 1 for supplying combustion gas and capable of adjusting the denitrification agent injection angle relative to the flow direction of the combustion gas; and a control unit (e.g., control device 100) that controls the injection angle of the first nozzle based on information related to the temperature of the combustion gas.

[0192] Based on this structure, by changing the spray angle of the nozzle 80, the denitrification agent can be introduced in a way that allows it to react at a temperature close to the target temperature.

[0193] Therefore, even without setting multiple nozzles along the height direction, it is possible to cope with temperature changes inside the furnace and improve workability.

[0194] (2) Regarding the catalystless denitrification system 200 of the second method, in the catalystless denitrification system 200 described in (1), the control unit (e.g., control device 100) performs control as follows:

[0195] When the temperature of the combustion gas is lower than a specified reference, the injection angle of the first nozzle (e.g., nozzle 80) is controlled by injecting the denitrifying agent upstream of the flow direction of the combustion gas. When the temperature of the combustion gas is higher than the specified reference, the injection angle of the first nozzle (e.g., nozzle 80) is controlled by injecting the denitrifying agent downstream of the flow direction of the combustion gas.

[0196] Based on this structure, the denitrifying agent can be introduced in a manner that allows it to react at temperatures close to the target temperature across a wide range.

[0197] (3) Regarding the catalystless denitrification system 200 of the third method, in the catalystless denitrification system 200 described in (1) or (2), the flow path (e.g., the furnace 43) includes a first region (e.g., the front region FR) and a second region (e.g., the rear region BR) in a cross section along a direction intersecting the flow direction of the combustion gas. The denitrification agent supply unit 210 includes a first nozzle (e.g., nozzles 81A, 81C, 82A, 82C) configured corresponding to the first region and a second nozzle (e.g., nozzles 81B, 81D, 82B, 82D) configured corresponding to the second region. The control unit (e.g., the control device 100) controls at least one of the amount of denitrification agent injected from the first nozzle and the amount of denitrification agent injected from the second nozzle based on the temperature difference between the temperature of the combustion gas detected with respect to the first region and the temperature of the combustion gas detected with respect to the second region.

[0198] Based on this structure, when the combustion gas flow distribution is uneven, more denitrification agent can be sprayed onto the side with more combustion gas, thus improving the denitrification rate.

[0199] (4) The combustion device 1 of the fourth type includes the above-described flow path (e.g., furnace 43) and the catalystless denitrification system 200 as described in any one of (1) to (3).

[0200] This structure allows for handling of furnace temperature variations even without multiple nozzles along the height direction, and also improves workability.

[0201] (5) The fifth method of denitrification is a method of injecting denitrifying agent into the flow path of the combustion gas in the combustion equipment, wherein the injection angle is changed according to information related to the temperature of the combustion gas, the injection angle being the injection angle relative to the flow direction of the combustion gas and the injection angle of the denitrifying agent being injected from the nozzle 80.

[0202] This structure allows for handling of furnace temperature variations even without multiple nozzles along the height direction, and also improves workability.

[0203] (6) The extended nozzle 300 of the sixth method includes: a stationary part 86, a pipe 85 that can be connected to the combustion device 1 to receive denitrification agent; a movable part 87 that is rotatably connected to the stationary part 86 and includes an injection port 87h that can spray the denitrification agent flowing from the pipe 85 into the stationary part 86 to the outside; and an adjustment mechanism 88 that can adjust the angle of the movable part 87 relative to the stationary part 86.

[0204] Based on this structure, by installing an extended nozzle 300 on the original combustion equipment, a nozzle 80 that can adjust the injection angle of the denitrification agent can be provided.

[0205] Industrial availability

[0206] The catalyst-free denitrification system, combustion equipment, denitrification method, and extended nozzle of the present invention can improve workability.

[0207] Explanation of symbols

[0208] 1-Combustion equipment, 43-Furnace (flow path), 80-Nozzle, 81A, 81C, 82A, 82C-Nozzle (first nozzle), 81B, 81D, 82B, 82D-Nozzle (second nozzle), 85-Pipe section, 86-Stationary section, 87-Moving section, 88-Adjustment mechanism, 91-First temperature detection section, 91A-Front temperature detector, 91B-Rear temperature detector, 92-Second temperature detection section, 92A-Front temperature detector, 92B-Rear temperature detector, 100-Control device (control section), 200-Catalyst-free denitrification system, 210-Denitrification agent supply section, 300-Extended nozzle, FR-Front area (first area), BR-Rear area (second area).

Claims

1. A catalyst-free denitrification system, comprising: A denitrification agent supply unit includes a first nozzle disposed in a flow path within a combustion device and capable of adjusting the denitrification agent injection angle relative to the flow direction of the combustion gas. The combustion device includes a grate for conveying the combusted material and the flow path disposed above the grate, with the combustion gas flowing upwards. The control unit controls the injection angle of the first nozzle based on information related to the temperature of the combustion gas. Viewed from above, the flow path, in a cross-section along a horizontal direction intersecting the flow direction of the combustion gases, includes a first region and a second region located downstream of the first region in the direction of transport of the combusted material. The denitrification agent supply unit includes a first nozzle configured corresponding to the first region and a second nozzle configured corresponding to the second region. The control unit controls at least one of the amounts of the denitrifying agent injected from the first nozzle and the second nozzle based on the temperature difference between the temperature of the combustion gas detected with respect to the first region and the temperature of the combustion gas detected with respect to the second region.

2. The catalyst-free denitrification system according to claim 1, wherein, The control unit performs the following control: When the temperature of the combustion gas is lower than a predetermined reference, the injection angle of the first nozzle is controlled by injecting the denitrification agent upstream of the flow direction of the combustion gas. When the temperature of the combustion gas is higher than the specified reference, the injection angle of the first nozzle is controlled by injecting the denitrification agent downstream of the flow direction of the combustion gas.

3. A combustion device comprising the grate, the flow path, and the catalyst-free denitrification system as described in claim 1 or 2.

4. A denitrification method, comprising injecting a denitrification agent into a flow path supplying combustion gases in a combustion device, wherein the combustion device includes a grate for conveying the combusted material and a flow path disposed above the grate with the combustion gases flowing upwards. Viewed from above, the flow path, in a cross-section along a horizontal direction intersecting the flow direction of the combustion gases, includes a first region and a second region located downstream of the first region in the direction of transport of the combusted material. In the aforementioned denitrification method The injection angle is adjusted based on information related to the temperature of the combustion gas. This injection angle is relative to the flow direction of the combustion gas and is the injection angle at which the denitrification agent is injected from the first nozzle. The amount of denitrifying agent injected from the first nozzle configured corresponding to the first region and the amount of denitrifying agent injected from the second nozzle configured corresponding to the second region are controlled based on the temperature difference between the temperature of the combustion gas detected with respect to the first region and the temperature of the combustion gas detected with respect to the second region.

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