CN1782499A - After-air nozzle for two-stage combustion boiler, and a two-stage combustion boiler, and combustion method using the same - Google Patents
After-air nozzle for two-stage combustion boiler, and a two-stage combustion boiler, and combustion method using the same Download PDFInfo
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- CN1782499A CN1782499A CN 200510117514 CN200510117514A CN1782499A CN 1782499 A CN1782499 A CN 1782499A CN 200510117514 CN200510117514 CN 200510117514 CN 200510117514 A CN200510117514 A CN 200510117514A CN 1782499 A CN1782499 A CN 1782499A
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Abstract
This invention provides an after-air nozzle and a boiler having thereof capable of reducing NOx and CO at the same time. This invention is characterized in that it has a vena contracta (24) such that an outside diameter of a flow passage diminishes towards the air-jetting port (16) which supplies air to a boiler (18), and a changing apparatus (26-32) of a flow passage cross-sectional area to change a flow passage cross-sectional area of the vena contracta (24). Using the after-air nozzle of this invention makes it possible to reduce NOx and CO concentrations at the same time.
Description
Technical field
The present invention relates to the structure that a kind of secondary firing formula boiler is used the additional gas nozzle and used its secondary firing formula boiler.
Background technology
In boiler, require the concentration of nitrogen oxide (Nox) to reduce, for corresponding to this requirement, adopt the secondary firing method.This method is the method that the air that completing combustion uses is provided after making fuel combustion under the state of lack of air, from additional gas (afterair) nozzle.Mix and fired state in order to improve air, proposed the structure of several additional gas nozzles.
For example, as Fig. 1 of patent documentation 1 (spy opens flat 10-122546 communique) puts down in writing, proposed in the additional gas nozzle, to have the structure of the diminishing contracted flow of the outer radial air ejiction opening portion of air flow circuit.But, in nearest boiler, require to reduce Nox and CO simultaneously, but these formations only can reduce one of Nox and CO.
Patent documentation 1: the spy opens flat 10-122546 communique
Summary of the invention
The present invention proposes a kind of structure that can reduce the additional gas nozzle of Nox and CO simultaneously.
A scheme of dealing with problems of putting down in writing in the embodiment is a kind of secondary firing additional gas nozzle with boiler, wherein, has: the stream outer radial offers the contracted flow portion that the air ejiction opening of boiler dwindles with air; Flow path cross sectional area modifier with the flow path cross sectional area that changes described contracted flow portion.
The present invention has following invention effect:
The additional gas nozzle of the application of the invention can reduce Nox and CO in the secondary firing boiler simultaneously.
Description of drawings
Fig. 1 is the longitudinal sectional view of the additional gas nozzle of expression embodiment of the present invention.
Fig. 2 is the cutaway view along additional gas nozzle A-A ' line shown in Figure 1.
Fig. 3 is the cutaway view along the additional gas nozzle C-C ' line of Fig. 1.
Fig. 4 is the cutaway view along the additional gas nozzle A-A ' line of Fig. 1.
Fig. 5 is the longitudinal sectional view of additional gas nozzle of the variation of explanation embodiment of the present invention shown in Figure 1.
Fig. 6 is the longitudinal sectional view of the additional gas nozzle of expression embodiment of the present invention 2.
Fig. 7 is the longitudinal sectional view along the additional gas nozzle of the D-D ' line of Fig. 6.
Fig. 8 is the longitudinal sectional view of additional gas nozzle of variation of the embodiment of presentation graphs 6.
Fig. 9 is the longitudinal sectional view of the additional gas nozzle of expression embodiment of the present invention 3.
Figure 10 is the figure that sees the adjusting device of the additional gas nozzle shown in Fig. 9 from the burner hearth outside.
Figure 11 is the longitudinal sectional view along the additional gas nozzle of the E-E ' line of Fig. 9.
Figure 12 is the longitudinal sectional view of the additional gas nozzle of expression embodiment of the present invention 4.
Figure 13 is the longitudinal sectional view of the additional gas nozzle of expression embodiment of the present invention 5.
Figure 14 is the longitudinal sectional view of additional gas nozzle of variation of the embodiment of the present invention of presentation graphs 4.
Figure 15 is the experimental result of checking effect of the present invention.
Figure 16 is the cutaway view of the burner hearth combustion gas flow direction of expression embodiment of the present invention.
Figure 17 is the cutaway view along the F-F ' line of Figure 16.
Figure 18 be expression one embodiment of the invention pulverized-coal fired boiler hearth portion the cross section and, the figure that system is provided of air and coal dust.
Figure 19 is the formation of main additional gas nozzle of expression one embodiment of the invention and the cutaway view of air-flow direction.
Figure 20 A is the figure of collocation method one example of the auxilliary additional gas nozzle of advocating peace among expression the present invention.
Figure 20 B is the figure of collocation method one example of the auxilliary additional gas nozzle of advocating peace among expression the present invention.
Figure 21 is the cutaway view of the main additional gas nozzle of yet another embodiment of the invention.
Figure 22 is the flame temperature in the expression additional gas burning portion and the graph of a relation of Nox growing amount.
Figure 23 is the figure of the relation of the flow velocity of the contracted flow portion of expression when using the additional gas nozzle of one embodiment of the invention and flame temperature.
Figure 24 is the figure of the relation of expression when using the additional gas nozzle of one embodiment of the invention to change the flow velocity of contracted flow portion, Nox and CO.
Figure 25 is the Nox among the present invention and the relation figure compared with the prior art of CO characteristic.
Figure 26 is by the formation of the present invention figure of the relation of the flow velocity of additional gas and Nox and CO compared with the prior art.
Figure 27 be the contracted flow portion of expression when using the additional gas nozzle of one embodiment of the invention flow velocity, with the figure of the relation of Nox and CO combination property.
Figure 28 is the figure of example of the result of calculation of expression checking effect of the present invention.
The specific embodiment
Below, the structure and the using method thereof of additional gas nozzle of the present invention are described with reference to accompanying drawing.
(embodiment 1)
Fig. 1 is the longitudinal sectional view of an example of the embodiment of expression additional gas nozzle of the present invention.The additional gas nozzle is surrounded by bellows urceolus 10, flows into from peristome 12 combustion airs of the back quadrate part that is arranged at bellows urceolus 10.Air stream 14a-14f flows along arrow, sprays to burner hearth internal combustion space 18 from ejiction opening 16.The air of ejection with after fuel gas mixes, makes gas fuel burning in burner hearth internal combustion space 18.Be wound in ejiction opening 16 around water pipe 20 is set.Ejiction opening 16 sides at the additional gas nozzle are provided with contracted flow parts 22.Contracted flow parts 22 are configured to bore and diminish gradually to ejiction opening 16 sides.
Utilize the air stream 14a-14f shown in 22 pairs of arrows of these contracted flow parts that velocity component towards nozzle center's axle is provided, form contracted flow portion 24.Near the inlet of contracted flow portion 24, the parts 26 of the minimum flow path area of regulation contracted flow portion 24 are set.Air velocity in the contracted flow portion 24 is stipulated by the area of the minimum stream 28 of contracted flow portion 24.In the formation of Fig. 1,, form the minimum stream 28 of contracted flow portion 24 at the leading section of the parts 26 of the minimum flow path area of regulation contracted flow portion 24.
The parts 26 of the minimum flow path area of the regulation contracted flow portion 24 of Fig. 1 constitute external diameter and diminish gradually towards ejiction opening 16.This is in order to reduce the disorder of flowing in the contracted flow portion 24.Utilize and reduce disorder, suppress the rapid increase of Nox easily.
The parts 26 of the minimum flow path area of regulation contracted flow portion 24 are fixed on the support member 30 of parts 26 of the minimum flow path area that supports regulation contracted flow portion 24.The support member 30 of the parts 26 of the minimum flow path area of support regulation contracted flow portion 24 is fixed on the slip ring 32.Slip ring 32 is installed on the inner core 34.Slip ring 32 is fixing each other with inner core 34, and slip ring 32 can be along moving towards the direction of the bellows outer wall 36 of Fig. 1 or towards the direction of ejiction opening 16.
By mobile slip ring 32, the support member 30 of the parts 26 of the minimum flow path area of support regulation contracted flow portion 24, also mobile simultaneously with the parts 26 of the minimum flow path area of stipulating contracted flow portion 24.If move the parts 26 of the minimum flow path area of regulation contracted flow portion 24, then the area change of the minimum stream 28 of contracted flow portion 24.At this moment, the external diameter that is shaped as of contracted flow portion 24 remains unchanged, internal diameter varies, and the result changes as the sectional area perpendicular to nozzle center's axle of the flow path cross sectional area of contracted flow portion 24.
As described later,, do not change the change that this flow path cross sectional area is adjusted on stream external diameter ground, can reduce Nox and CO simultaneously by the contracted flow portion 24 that stream outer radial air ejiction opening 16 dwindles is set.If guide roller 38 is installed on one of slip ring 32 or inner core 34, then can level and smooth mobile slip ring 32.By slip ring mover bar fixed mechanism 40, slip ring mover bar 42, handle 44 are installed on slip ring 32, can the parts 26 of the minimum flow path area of regulation contracted flow portion 24 be moved from the outside (among Fig. 1, seeing it is to be the left side) of bellows outer wall 36.
Inboard at the parts 26 of the minimum flow path area of regulation contracted flow portion 24 is provided with and prevented warmware 46.Be used for preventing owing to, burn out the support member 30 of the parts 26 of the minimum flow path area that supports regulation contracted flow portion 24 from the flame radiation heat that is formed at burner hearth internal combustion space 18.Under the situation a little less than the Fire Radiation heat in being formed at burner hearth internal combustion space 18, maybe can utilize other method to come under the situation of cooled supports part 30, may not necessarily need prevent warmware 46.
If guiding piece 48 is assemblied on the slip ring 32, then when slip ring 32 was moved, the core of the parts 26 of the minimum flow path area of regulation contracted flow portion 24 was difficult to dislocation.In addition, can firmly fix the support member 30 of slip ring 32 and the parts 26 of the minimum flow path area that supports regulation contracted flow portion 24.In addition, the turbulent flow of easy rectification air.The inner end of guiding piece 48 is fixed on the outside of slip ring 32, the inner surface of outer end contact bellows urceolus 10, slidably.
Position relations when the parts 26 that the minimum flow path area that makes regulation contracted flow portion 24 is described move forward and backward, parts 26 and contracted flow parts 22.Starting position (A-A ' cross section of Fig. 1) with contracted flow portion 24 is that benchmark illustrates the position relation.When moving to ejiction opening 16 sides to greatest extent, the leading section of parts 26 is positioned at than more close ejiction opening 16 sides in the starting position of contracted flow portion 24.At this moment, the mobile stage portion 49 that is set at the connecting portion of contracted flow portion 24 and bellows urceolus 10 of guiding piece 48 limits.On the contrary, to greatest extent aweather during box outer wall 36 side shiftings, the leading section of parts 26 becomes than more close bellows outer wall 36 sides in the starting position of contracted flow portion 24.Moving range also can with above-mentioned illustrate different, but in inventor's described later experiment, when being moving range shown in above-mentioned, the easiest Nox and the CO of reducing simultaneously.
A-A ' the direction of the nozzle of Fig. 1 shown in Fig. 2 and the cutaway view of B-B ' direction, the cutaway view of the direction of C-C ' shown in Fig. 3.Fig. 1 is equivalent to the cutaway view of the G-G ' direction of Fig. 2 and Fig. 3.In addition, Fig. 4 is the variation of the cutaway view of A-A ' direction, B-B ' direction among Fig. 1.In inventor's described later experiment, use the nozzle of cross section, even if but use rectangular nozzle shown in Figure 4 also can expect same effect as circle.
Fig. 5 is the longitudinal sectional view of additional gas nozzle of the variation of explanation embodiment of the present invention shown in Figure 1.Compared to Figure 1, the shape difference of the parts 26 of the minimum flow path area of regulation contracted flow portion 24.That is, the outer peripheral face of the parts 26,46 of Fig. 1 attenuates towards burner hearth internal combustion space 18, but among Fig. 5, extends smooth for walking abreast.The necessary condition of these parts 26 is the areas that change the minimum stream 28 of contracted flow portion 24 by moving-member.As long as satisfy this condition, then also can be the shape of Fig. 5.
(embodiment 2)
Fig. 6 is the longitudinal sectional view of the embodiment 2 of expression additional gas nozzle of the present invention.Be with the difference of Fig. 1, the parts 26 that do not have the minimum flow path area that makes regulation contracted flow portion 24 move the inner core 34 of usefulness, have regulation contracted flow portion 24 minimum flow path area parts 26 support member 30 and be used to cool off the cooling air stream of contracted flow portion 24.Other additional part with Fig. 1 same-sign is omitted explanation, but has identical functions.
The parts 26 of the minimum flow path area of regulation contracted flow portion 24 are same as in figure 1, can move forward and backward.Though contracted flow parts 22 are different with the angle of the parts 26 of the minimum flow path area of regulation contracted flow portion, because can not change the area that the external diameter ground of contracted flow portion 24 changes the minimum stream 28 of contracted flow portion 24, so can expect the Nox/CO performance equal with Fig. 1.On the support member 30 of the parts 26 that support the minimum flow path area of stipulating contracted flow portion 24, cooling air hole 50,52 is set.
The part of air stream 14a, the 14d that imports from bellows peristome 12 becomes cooling air stream 54a-54c, emits from cooling air hole 52.In this process, impact the support member 30 of the parts 26 of the minimum flow path area that supports regulation contracted flow portion 24, can cool off this parts 30.In addition, the air of emitting from cooling air hole 50 flows the parts 26 that 54d, 54e impact the minimum flow path area of regulation contracted flow portion 24, also can cool off these parts 26.
And, near contracted flow portion 24, cooling air guide plate 56 is set.Cooling air 54f, 54g flow through between cooling air guide plate 56 and the contracted flow parts 22, can cool off contracted flow parts 22.In addition, because this cooling air 54f, 54g flow through the most peripheral side of ejiction opening 16, so also can be used for removing the coal ash that is attached to around the contracted flow parts 22.
Fig. 7 is the D-D ' cutaway view of Fig. 8.In cooling air hole 50,52, circular a plurality of apertures, the peristome of slot shape etc. are arranged.Fig. 7 is the example that circular a plurality of apertures are set.Fig. 8 is the variation of Fig. 6, is configured to adjust the air capacity of cooling contracted flow parts 22.Cooling air introducing port 58 is set on bellows urceolus 10.Around cooling air introducing port 58, movable cooling air adjustment is set with pilot sleeve 60, adjust cooling air volume.
Can be used for when be attached to ejiction opening 16 around on coal ash quantitative change for a long time, the temporary transient air capacity that flows through between contracted flow parts 22 and the cooling air guide plate 56 that increases, ash is adhered in removal easily.In addition, the angle of contracted flow parts 22 also can be in the variation midway of contracted flow portion 24.Based on the reasons such as restriction of making on the nozzle, also can change the shape of guiding piece 48 as shown in Figure 8.In the formation of Fig. 8, near the angle the inlet of contracted flow portion 24 is big, and near the angle the outlet of contracted flow portion 24 is little.The structure that is shaped as the part of cutting away outer peripheral portion of guiding piece 48.If form the shape of guiding piece 48 as shown in Figure 8, then can reduce to flow into the disorder of the air stream in the contracted flow portion 24, effective to reducing Nox.
(embodiment 3)
Fig. 9 is the cutaway view of an example of expression additional gas nozzle embodiment of the present invention.The nozzle structure that utilization has inner core 34 can will cool off the inboard that air imports inner core 34 by airport 61.In the outside of inner core 34, slip ring inner core 62 is installed, in the inboard of bellows urceolus 10, slip ring urceolus 64 is installed.Slip ring inner core 62 is connected, is fixed by guiding piece 48 with slip ring urceolus 64.In this structure, can alleviate moving part.
In the structure of Fig. 9, on the part of ejiction opening 16 sides of inner core 34, utilize support component 65 to be provided with and prevented warmware 46.Prevented warmware 46 if constitute by the fire-resistant/heat-insulating material etc. of pottery system, then since the Heavy Weight of inner core 34 be difficult to the heavy warmware 46 that prevented is used for moving part.If the structure of Fig. 9 then can prevent the parts 26 of the minimum flow path area of the not mobile movably regulation contracted flow of warmware 46 portion.On the parts 26 of the minimum flow path area of regulation contracted flow portion 24, install and promote the cold plate 66 that advances.Thus, the air capacity that can lack is cooled off the parts 26 of the minimum flow path area of regulation contracted flow portion.
On slip ring inner core 62, slip ring urceolus 64 or guiding piece 48 (being slip ring inner core 62 among Fig. 9), fixedly slip ring mover bar fixed mechanism 40, slip ring mover bar 42.On slip ring mover bar 42, slip ring shifter 68 is installed.If slip ring shifter 68 is moved, then the parts 26 of the minimum flow path area of regulation contracted flow portion 24 move.
Rotating disc 74 is connected with rotary handle 76 through belt or chain 78, and by making rotary handle 76 rotations, rotating disc 74 also rotates.Rotary handle 76 can smoothly be connected on the rotating shaft 80 rotatably.Adjustment transfiguration when the advantage of this structure is burning is easy.When wanting to reduce Nox, as long as make rotary handle 76 rotate, the parts 26 of the minimum flow path area of regulation contracted flow portion 24 are moved to the direction of ejiction opening 16.When wanting to reduce CO, as long as opposite spin rotary handle 76.
If slip ring urceolus 64 is moved, a part that then can inaccessible bellows peristome 12.Thus, even if the parts 26 of the minimum flow path area of regulation contracted flow portion 24 are moved, also can will keep constant from bellows peristome 12 leaked-in air amounts.If the flow path cross sectional area of contracted flow portion 24 is reduced, then the stream impedance of this part becomes big, and air is difficult to flow.
In the formation of Fig. 9, at this moment, it is big that the flow path cross sectional area of bellows peristome 12 becomes, and the stream impedance of this part diminishes.When the flow path cross sectional area that makes contracted flow portion 24 increases, then opposite.That is if see, then be, if increase the stream impedance of part, the formation that reduces of the stream impedance of other parts so so that additional gas is nozzle-integrated.
If the size and shape of optimization bellows peristome 12,, also can the stream impedance when seeing keep constant so that additional gas is nozzle-integrated even if then change the flow path cross sectional area of contracted flow portion 24.In addition, will not air mass flow keeping under the constant situation, or can adjusted under the situation of air mass flow by other method, may not be this formation.
Figure 10 is the figure that sees from bellows outer wall 36 sides.Near rotary handle, plate 84 is set, record direction of rotation and the effect that can expect.Because the effect of content of operation and expectation comes into plain view, so even if unskilled operator, can maloperation yet.Figure 11 is the cutaway view of the E-E ' direction of Fig. 9.
(embodiment 4)
Figure 12 is the longitudinal sectional view of an example of the embodiment of expression additional gas nozzle of the present invention.
Be made as the structure of parts 26 of the minimum flow path area of commutative regulation contracted flow portion 24.The support member 30 of the parts of the minimum flow path area of regulation contracted flow portion 24 is installed in by removable screw 86a, 86b and pulls down on the formula inner core 88.To pull down formula inner core 88 and be fixed on and pull down on the formula bellows outside plate 90, and utilize removable screw 92a, 92b that bellows outside plate 90 is installed on the bellows outer wall 36.
In this constitutes,, can stipulate the parts 26 of the minimum flow path area of contracted flow portion 24 from the outside (left side of Figure 12) exchange of bellows outer wall 36 by pulling down screw 86a, 86b.By the several parts 26 of prior preparation, and exchange, can change the flow path cross sectional area of contracted flow portion 24 simply.In addition, in this embodiment, pull down formula inner core 88 and possess airport 91a, 91b, 91c, 91d, air stream 93a, 93b, 93c, 93d are respectively by airport 91a-91d circulation.
(embodiment 5)
Figure 13 is the cutaway view of an example of the embodiment of expression additional gas nozzle of the present invention.Be have two nozzles, be contracted flow nozzle 94 and the structure that directly advances nozzle 96.Because the central part at the additional gas nozzle does not have object, cooling construction is simple and easy.By slip ring 32 is moved forward and backward, the flow path cross sectional area of the outlet of contracted flow portion 24 is changed.Figure 17 is the variation of Figure 16, changes the position that is provided with of slip ring 32.
Utilize combustion experiment to verify effect of the present invention.Checking to as if be similar to the additional gas nozzle of Fig. 1 structure.Object also implements to use the experiment of following 5 kinds of nozzles as a comparison.
(1) though be the formation that is similar to Fig. 1, can not change the nozzle (contracted flow nozzle 1) of the stream of contracted flow portion
(2) though be the formation that is similar to Fig. 5, can not change the nozzle (contracted flow nozzle 2) of the stream of contracted flow portion
(3) directly advance/circle round nozzle (directly advancing/circle round nozzle)
(4) directly advance nozzle (directly advancing nozzle 1)
(5) flow path area is changeable directly advances nozzle (directly advancing nozzle 2)
Directly advancing/circling round in the nozzle, utilizing swirl vanes, the air stream of outer circumferential side is being provided circle round.Directly advancing nozzle 1 and only possess air nozzle 1 time, is that the most simple nozzle constitutes example.In directly advancing nozzle 2, nozzle is made multiple pipe structure, by the damper that is equipped with in the inlet that opens and closes each air nozzle, can change the flow path cross sectional area of nozzle.It is identical with the present invention to change flow path cross sectional area, but the form difference of stream.In directly advancing nozzle 2, when changing flow path cross sectional area, the external diameter of air flow circuit changes.
Figure 15 illustrates the result of confirmatory experiment.In experiment, the air ratio with the fuel amount of providing, the air amount of providing, burner portion and burner hearth integral body keeps constant as far as possible, relatively the independent performance of nozzle.Performance is estimated with the concentration of Nox in the exhaust of furnace outlet and CO.Nox concentration is come comparison with the 6%O2 scaled value, and CO concentration is come comparison with the 3%O2 scaled value.
The performance of the existing CO of Nox when using 5 kinds of nozzles of object as a comparison is roughly between dotted line 108 and 109.Performance when on the other hand, using nozzle of the present invention probably is the value shown in the curve 107.In formation of the present invention, can obviously reduce CO concentration.Even if the optimum value of Nox performance, formation of the present invention also is better than the formation of comparison other.According to this result, utilize formation of the present invention can reduce Nox and CO simultaneously as can be known.
Mark 102 is results of contracted flow nozzle 1, and mark 103 is results of contracted flow nozzle 2.Compare with other nozzle of comparison other, the performance of Nox and CO is good as can be known.Sometimes also poor.The stream shape that only has a contracted flow portion by formation can not reduce Nox and CO simultaneously as can be known.
Mark 104 is the results that directly advance nozzle 2.Compare with the nozzle of other comparison other that can not change flow path area, the performance of Nox and CO is so not good as can be known.Compared with directly advancing nozzle 1, can reduce CO, but Nox increased this moment.Can utilize the change of flow path area to improve one of Nox and CO performance, but only can not reduce Nox and CO simultaneously by this formation.
Mark 106 is the results that directly advance nozzle 1.The bore of the ejiction opening of this nozzle is identical with nozzle of the present invention.The performance of Nox and CO is not only determined by the bore of nozzle as can be known.
Nozzle of the present invention is compared with directly advancing nozzle 2, and Nox and CO performance are good.In addition, according to the result of the result of contracted flow nozzle 1 and contracted flow nozzle 2 and nozzle of the present invention more as can be known, have the nozzle of contracted flow portion, can change flow path area by constituting, the raising effect of the performance of Nox and CO is big.
From above experimental result as can be known, in order to reduce Nox and CO simultaneously, following formation is a necessary condition.
The nozzle that has contracted flow portion in face of ejiction opening constitutes.
Can change the stream of contracted flow portion.
The external diameter ground that can not change air flow circuit changes the sectional area of air flow circuit.
(embodiment 6)
Figure 16 is an example of the embodiment of additional gas nozzle of the present invention, is to use the pie graph of the coal dust firing of additional gas nozzle of the present invention with burner hearth.The wall of burner hearth is surrounded by the burner hearth roof 110 on top, the funnel 112 of bottom, burner hearth antetheca 114, burner hearth rear wall 116 and the burner hearth sidewall 136 (putting down in writing among Figure 17) of side, on each wall, not shown water pipe is set.This water pipe absorbs the part of the combustion heat that produces in the burner hearth combustion space 18.The burning gases that in burner hearth combustion space 18, generate from below flow to above, discharge gas 118 backs that become after the burning.Gas 118 after the burning further reclaims the heat that is contained in the gas here by not shown rear portion heat transfer part.
In the bottom of burner hearth, burner 120 is set, form the flame 122 of lack of air here.Coal is being pulverized by not shown pulverizer into about after below 150 microns, by the air transmission, burner is ejected in the burner hearth from burner with 1 air and coal dust 124.Burner also sprays from burner with bellows 128 via burner simultaneously with 2 times, 3 times air 126.
Above burner, additional gas nozzle 130 is set.Usually, the part of air that will provide as 2 times, 3 times air of burner is come branch as additional gas air 132, is ejected into burner hearth combustion space 18 from additional gas nozzle 130.On the top of burner hearth rear wall 116, nose 134 is set.Because the influence of this nose 134, the burning gases rheology around the additional gas nozzle 130 is asymmetric.
Figure 17 is the F-F ' cutaway view of Figure 16.Usually, dispose a plurality of additional gas nozzles 130 with burning gases stream with meeting at right angles.Among Figure 17, the additional gas nozzle 130 of close burner hearth sidewall 136 configurations and the additional gas nozzle 130 of close burner hearth central configuration are arranged.Because the influence of wall, the stream mode of burning gases or temperature are different with center side in burner hearth sidewall 136 sides.
Because the influence of these noses 134 or burner hearth sidewall 136, the additional gas nozzle 130 of configuration are placed under the environment of the stream that has nothing in common with each other or temperature.In order to comprise Nox, CO, the burning condition in the burner hearth to be become the state of expecting most, expectation also respectively becomes optimum state with air from the condition that additional gas nozzle 130 sprays corresponding to environment is set.
Additional gas nozzle of the present invention 130 be owing to can finely tune the stream mode that is arranged on the contracted flow portion 24 in each additional gas nozzle 130 separately, thus can be corresponding to environment be set, and the condition that air is sprayed from each additional gas nozzle 130 remains on optimum state.By the present invention, can only study intensively the additional gas nozzle and construct and reduce Nox and CO simultaneously.
In addition, additional gas nozzle of the present invention is owing to be provided as the parts of the minimum flow path area of regulation of flow path cross sectional area change parts in the inside of additional gas nozzle, so stipulate the parts of minimum flow path area if move this, then the external diameter of the shape of contracted flow portion can remain unchanged, and makes internal diameter varies.Therefore, the sectional area perpendicular to nozzle center's axle as the flow path cross sectional area of contracted flow portion is changed.
In addition, additional gas nozzle of the present invention is provided with the parts of the minimum flow path area of regulation contracted flow portion in the inside of additional gas nozzle, moves the parts of the minimum flow path area of regulation contracted flow portion by longshore current road direction, can change the flow path cross sectional area of contracted flow portion.Therefore, needn't decompose the additional gas nozzle for the flow path cross sectional area that changes contracted flow portion, the parts of the minimum flow path area of regulation are changed into other parts, only, just can easily change the flow path cross sectional area of contracted flow portion by moving the parts of the minimum flow path area of regulation.
In addition, additional gas nozzle of the present invention is provided with the parts of the minimum flow path area of regulation contracted flow portion in the inside of additional gas nozzle, the structure of the parts of the minimum flow path area of regulation contracted flow portion for exchanging separately, owing to be to change the structure of the flow path cross sectional area of contracted flow portion by the exchange of parts, can change the shape of the parts of the minimum flow path area of regulation.
(embodiment 7)
In the present invention, be desirably in the parts that the minimum flow path area of regulation contracted flow portion is set within the main additional gas nozzle.In addition, main additional gas nozzle expects that by providing by the direct flow or the stream that circles round for 1 time of air and 2 nozzles, constituting with 3 nozzles that 3 air are provided that are arranged on described 1 time and the 2 times nozzle outside described 3 nozzles are at the velocity component that has center position on the central axis direction of additional gas jet flow.In addition, the mechanism of expecting to possess the mechanism that regulates the air total amount that offers main additional gas nozzle and auxilliary additional gas nozzle and regulating the ratio of the air capacity that offering the auxilliary additional gas nozzle of advocating peace.
Be desirably on the burner hearth antetheca of boiler and the burner hearth rear wall and respectively dispose a plurality of main additional gas nozzles and auxilliary additional gas nozzle respectively.In addition, the auxilliary additional gas nozzle of expectation be configured in main additional gas nozzle directly over, or be configured in downstream between a plurality of main additional gas nozzles or burner hearth sidewall near.Further feature of the present invention becomes clear by the following examples.
Figure 18 uses the pie graph of hearth portion of the coal dust burning boiler of coal dust as the embodiment of the invention, in fuel.The wall of burner hearth is surrounded by the burner hearth roof 110 on top, the funnel 112 of bottom, burner hearth antetheca 114, burner hearth rear wall 116 and the burner hearth sidewall 136 shown in Figure 20 of side, on each wall, not shown water pipe is set.Utilize this water pipe to absorb the part of the combustion heat that produces in the burner hearth combustion space 18.The burning gases that in burner hearth combustion space 18, generate from below flow to above, discharge gas 118 backs that become after the burning.Gas 118 after the burning further reclaims the heat that is contained in the gas here by not shown rear portion heat transfer part.
In the bottom of burner hearth, burner 120 is set, form the flame 122 of lack of air here.Burner 120 by the ejection burner with the coal nozzle of the mixed flow 124 of 1 air and coal dust with spray burner and constitute with 2 nozzles of 2 air and 3 nozzles spraying 3 air.Coal is transmitted with 1 air by burner being pulverized by not shown pulverizer into about after below 150 microns, and the mixed flow 124 of burner with 1 air and coal dust is ejected in the burner hearth from burner 120.Burner also sprays from burner 120 with bellows 128 via burner simultaneously with 2 times, 3 times air 126.
Above burner 120, main additional gas nozzle 140 is set.In the downstream of main additional gas nozzle, auxilliary additional gas nozzle 141 is set.Main additional gas nozzle 140 be configured near ejiction opening, contracted flow type structure that air stream constitutes towards main additional gas nozzle center direction of principal axis.The details of structure is described in Figure 19,21.The unburnt ingredient major parts such as CO that the flame 122 of the lack of air that forms in burner portion produces are by mixing and completing combustion (oxidation) with the air that comes autonomous additional gas nozzle.But, produce Nox when unburnt ingredient mixes with main additional gas air.This Nox mainly is hot Nox.The generation of Nox is with relevant from the air velocity (Peak Flow Rate of contracted flow portion) of main additional gas nozzle ejection, and the flow velocity of adjusting main additional gas air is important.And, if the ejection condition of setting main additional gas air easily produces the tendency of CO, so need be careful the ejection condition that the performance balance of Nox and CO is set main additional gas air so that the Nox step-down then has oxidation insufficient.
As a result, can the Nox that burner portion is produced remain at minimum in, the air ejection condition that guarantees main additional gas nozzle is so that combination property the best of Nox and CO.
In addition, 2 times, 3 times air 126 that offer burner are also the same with additional gas air 132, distribute guiding mechanism 146 to be distributed into the air and the air that flows to the burner of rear wall side of the burner that flows to the antetheca side by air mass flow.
Figure 19 is the cutaway view of an example of the detailed construction of the main additional gas nozzle of expression.The essential structure of the main additional gas nozzle of Figure 19 is for being the cylindrical shape of central shaft with jet flow central shaft 147.Nozzle is surrounded by bellows urceolus 10 and bellows outer wall 36, and the air of burner is pressed shown in the arrow 14a and flowed into from bellows peristome 12.Air flows along the direction of arrow 14a, 14b, is ejected into burner hearth internal combustion space 18 from ejiction opening 16.The air of ejection with after fuel gas mixes, makes gas fuel burning in burner hearth internal combustion space 18.Around ejiction opening 16, water pipe 20 is set.Ejiction opening 16 sides at the additional gas nozzle are provided with contracted flow parts 22.Contracted flow parts 22 are configured to bore and diminish gradually to ejiction opening 16 sides.By these contracted flow parts 22, apply velocity component to the air stream shown in arrow 14a, the 14b towards nozzle center's axle, form contracted flow portion 24.Near the inlet of contracted flow portion 24, the parts 26 of the minimum flow path area of regulation contracted flow portion are set.The air velocity of contracted flow portion is by stipulating at the area of contracted flow portion aperture area least part.In the formation of Figure 19, in the leading section of the parts 26 of the minimum flow path area of regulation contracted flow portion, the flow velocity maximum of contracted flow portion.The parts 26 of the minimum flow path area of the regulation contracted flow portion of Figure 19 are made the formation that external diameter diminishes gradually towards ejiction opening 16 sides.This is in order to reduce the air turbulence in the contracted flow portion 24.By reducing disorder, suppress the rapid increase of Nox easily.The parts 26 of the minimum flow path area of regulation contracted flow portion are fixed on the support member 30.Support member 30 is fixed on the bellows urceolus 10 by guiding piece 48.In parts 26 inboards of the minimum flow path area of stipulating contracted flow portion, be provided with and prevented warmware 46.Be used for preventing owing to burn out support member 30 from the flame radiation heat that is formed at burner hearth internal combustion space 18.Under the situation a little less than the Fire Radiation heat in being formed at burner hearth internal combustion space 18, or can come under the situation of cooled supports part 30, may not necessarily need prevent warmware 46 by other method.
Figure 20 (a) (b) illustrates an example of the configuration of main additional gas nozzle and auxilliary additional gas nozzle.Figure 20 (a) is the A-A ' cutaway view of Figure 18, and the configuration of main additional gas nozzle 140 is shown.Figure 20 (b) is the B-B ' cutaway view of Figure 18, and the configuration of auxilliary additional gas nozzle 141 is shown.Usually with burner combustion gas stream meets at right angles or roughly dispose a plurality of main additional gas nozzles 140 with meeting at right angles, dispose equal number in burner hearth antetheca 114 sides and burner hearth rear wall 116 sides.The most simple collocation method of auxilliary additional gas nozzle 141 is configured in directly over the main additional gas 140.
The variation of main additional gas nozzle structure and the variation of additional gas nozzle arrangement are described below, but are not limited to these variation.
[variation 1 of main additional gas nozzle structure]
As the variation of the detailed construction of main additional gas nozzle, can use Fig. 6 or Fig. 8.
[variation 2 of main additional gas nozzle structure]
Figure 21 is the cutaway view of another variation of the main additional gas nozzle of expression.At the center of main additional gas nozzle, nozzle 148 is set 1 time, in 1 nozzle 148 outside, nozzle 149 is set 2 times, in the outside of 2 nozzles 149,3 nozzles 150 of contracted flow are set.In the main additional gas nozzle of this structure, 1 time air flows along the direction shown in the arrow 151, and in the outside of 1 nozzle, 2 times air flows along the direction shown in the arrow 152.Flow along the direction shown in the arrow 153 from 3 air of 3 nozzles of contracted flow, 150 ejections,, behind 2 air stream interflow shown in the arrow 152, flow into burner hearth internal combustion space 18 in the outlet of 2 nozzles 149.Here, the emission direction of 2 nozzles 149 is parallel to jet flow central shaft 147.And, apply rotating force by 2 air streams shown in 154 pairs of arrows 152 of 2 air throttle valves (レ ジ ス ).Because 3 nozzles 150 of contracted flow are towards the direction configuration of jet flow central shaft 147, so can form contracted flow.
Coal dust comprises ash in fuel.At this moment, if main additional gas nozzle go out the interruption-forming contracted flow, then the ash of fusion can be attached near the water pipe 20 of air port outlet in high-temperature combustion gas.If the apposition growth of ash also forms clinker, then may hinder mobilely, or because water pipe is damaged in the whereabouts.In this case,, increase by 2 times air mass flow, the temperature of clinker is descended, peel off thereby produce thermal stress by in clinker hour 3 air mass flows of reduction.
[variation 1 of additional gas nozzle arrangement]
In this variation 1, auxilliary additional gas nozzle 141 is configured in the downstream of 140 at main additional gas nozzle.Unburnt ingredient by 140 at main additional gas nozzle does not mix with air from main additional gas nozzle 140 ejections easily and discharges from burner hearth, easily becomes the reason that makes the increase of CO discharge rate.Therefore, if will assist the downstream that additional gas nozzle 141 is configured in 140 at main additional gas nozzle, then mix, so reduce CO easily from the air of these auxilliary additional gas nozzle 141 ejections unburnt ingredient easy and by 140 at main additional gas nozzle.
[variation 2 of additional gas nozzle arrangement]
In this variation 2, near the auxilliary additional gas nozzle 141 of configuration burner hearth sidewall 136.When unburnt ingredient during by 136 of main additional gas nozzle 140 and burner hearth sidewalls, the easiest generation CO.This is that here, the oxidation rate of CO or unburnt ingredient is the slowest because near the gas temperature the burner hearth sidewall 136 is low.Therefore, in order to make unburnt ingredient efficient oxidation, will assist additional gas nozzle 141 and be configured in burner hearth sidewall 136 sides by 136 of main additional gas nozzle 140 and burner hearth sidewalls.By will assisting additional gas nozzle 141 configuration than main additional gas nozzle 140 more close burner hearth sidewall sides, the oxidation transfiguration of the unburnt ingredient by 136 of main additional gas nozzle 140 and burner hearth sidewalls is easy, can reduce CO.
[compliance test result of the present invention]
Figure 22 is the result of the relation of expression flame temperature and Nox generation.To be the unburnt ingredient that produces from the flame of lack of air mix with air from main additional gas ejection flame temperature,, the maximum temperature in the zone of burning.Among Figure 22 shown in the circle mark is experimental result, and curve is a result of calculation.Nox and flame temperature height correlation.If the flame temperature height, then Nox is exponential function ground increases.Especially if flame temperature surpasses 1500 degree, the increase of Nox is obvious.
Figure 23 is to use main additional gas nozzle that Figure 19 constitutes, studies the result of the relation of the Peak Flow Rate of contracted flow portion and flame temperature by experiment.Burner air than base condition ± 2% scope in constant, make burner hearth air ratio variation.If the Peak Flow Rate of contracted flow portion accelerates, then flame temperature slowly increases.If the flow velocity of contracted flow portion surpasses certain steady state value, then flame temperature sharply increases.This means before the Peak Flow Rate of contracted flow portion arrives certain steady state value during, Nox slowly increases, but if surpass certain steady state value, then the increase of Nox becomes rapid.In addition, if the Peak Flow Rate of contracted flow portion accelerates, then opposite CO reduces.
When the Peak Flow Rate of contracted flow portion was slow, Nox was low, the CO height.On the other hand, when the Peak Flow Rate of contracted flow portion was fast, CO was low, and Nox sharply uprises.During before flow velocity reaches certain steady state value, CO increases and reduces along with flow velocity, but the increase of Nox is slow, so the combination property of Nox and CO improves along with the Peak Flow Rate of contracted flow portion.
Shown in Figure 24 when the flow velocity of contracted flow portion is slow (low speed), when best (optimum speed) and when fast (at a high speed) wait the result of the relation of mensuration Nox and CO under 3 conditions.Before will reaching certain steady state value, optimum condition is arranged, at this moment, the combination property of Nox and CO is best.No matter the velocity ratio optimum value is still slow soon, and the combination property of Nox and CO is all low.
Figure 25 is to use under the situation of main additional gas nozzle of main additional gas nozzle that Figure 19 constitutes and prior art the relatively result of Nox and CO performance.If burner air ratio and burner hearth air ratio are in base condition ± 2% scope.The constituting of prior art removed the formation behind 3 nozzles 150 of contracted flow from the formation of Figure 21.Symbol 156 is not apply result when circling round to 2 nozzles existing in constituting, and symbol 157 is to apply result when circling round to 2 nozzles existing in constituting, and symbol 158 is the results when changing nozzle diameter.Symbol 159 is the results under the formation of the present invention (Figure 19), the result when being the peak flow rate (PFR) of optimization contracted flow portion.In formation of the present invention, compared with prior art, reduce Nox and CO as can be known simultaneously.When being desirably in the contracted flow type master additional gas nozzle that constitutes shown in Figure 19 and 21, the flow velocity of optimization contracted flow portion.
Shown in Figure 26 compared with prior art, the relation of the flow velocity of main additional gas air and Nox and CO.The flow velocity here is the flow velocity of additional gas ejiction opening in the prior art.Flow velocity among the present invention is the peak flow rate (PFR) in the contracted flow portion.The Nox of symbol 121 expression prior aries, the CO of symbol 123 expression prior aries.Nox among symbol 122 expression the present invention, the CO among symbol 124 expression the present invention.
If flow velocity accelerates, then Nox increases, and on the other hand, CO reduces.This is in sight in the present invention and prior art both sides.The difference of the present invention and prior art is that the increase of Nox is slow, till flow velocity arrives certain steady state value.Therefore, under certain flow conditions, the combination property of Nox and CO has optimum value.In the prior art, even if under the lower condition of flow velocity, the Nox increment rate when increasing flow velocity is also big.Therefore, even if make change in flow, the combination property of Nox and CO also not too changes.
Figure 27 relates to the present invention, is the graph of a relation that the combination property of the flow velocity of contracted flow portion and Nox and CO is shown.If flow velocity is set at optimum value, then can reduce Nox and CO simultaneously.But if the velocity ratio optimum value is fast, then Nox sharply increases, thereby the combination property of Nox and CO sharply descends.It is the key that performance improves that flow velocity is remained near the optimum value.Therefore, by auxilliary additional gas nozzle is set, adjust the air capacity that spills into auxilliary additional gas nozzle, it is effective that the contracted flow portion flow velocity in the main additional gas nozzle is remained at optimum value.In addition, in the method, owing to can not change the interior contracted flow portion flow velocity of the main additional gas nozzle of air capacity ground control that offers burner, so the burning condition in the burner portion also can remain at the few optimum state of Nox generation.But under the situation of this method of use, if make the interior contracted flow portion change in flow of main additional gas nozzle, then the air spouting velocity that provides from auxilliary additional gas nozzle simultaneously also changes.Expectation is worked hard to the configuration of auxilliary additional gas nozzle, to reduce the influence that this variation causes Nox.
By calculating the Temperature Distribution in the burner hearth, the influence of the collocation method of the auxilliary additional gas nozzle of research.Figure 28 is the variations in temperature example of furnace height direction.Temperature is a cross section mean value.Dotted line 164 is the contracted flow portion Peak Flow Rate of main additional gas nozzle temperature when big.In this case, near the temperature maximum the main additional gas surpasses 1500 degree, and Nox uprises.In order to reduce Nox, need to reduce the air capacity that offers main additional gas nozzle, reduce near the temperature maximum of main additional gas.Solid line 165 is the variations in temperature when reducing the Peak Flow Rate of the air capacity offer main additional gas nozzle and optimization contracted flow portion.The temperature maximum step-down can reduce near the Nox that produces the main additional gas.But at this moment, if reduce the air capacity that offers main additional gas nozzle, the air capacity that then offers auxilliary additional gas nozzle increases, so may produce Nox near auxilliary additional gas.
Solid line 166 is near the temperature of auxilliary additional gas under the present invention constitutes.Because auxilliary additional gas nozzle is provided with also near the downstream than main additional gas nozzle, so utilize the heat release to hearth wall, near the ambient air temperature degree the auxilliary additional gas nozzle is lower than 1500 degree.Therefore, even if the ambient air temperature degree is also little to the influence that the Nox generation causes owing to the air velocity from auxilliary additional gas nozzle ejection changes.By being reduced near the Nox that produces the main additional gas, can reduce the Nox that from burner hearth integral body, produces.
Solid line 167 is near different with formation of the present invention, when the upstream side of main additional gas nozzle is provided with auxilliary additional gas nozzle, the auxilliary additional gas temperature.At this moment, gush out from the air of auxilliary additional gas nozzle near the environment gas gas temperature is 1500 degree.If temperature rises because of the increase of air velocity under this condition, then Nox easily sharply increases.Therefore, if make the air capacity to main additional gas nozzle reduce, reduce the Nox that produces here, the air velocity of then assisting the additional gas nozzle increases, near the opposite easily increase of Nox that produces the auxilliary additional gas.Therefore, be difficult to reduce the Nox that from burner hearth integral body, produces.
In addition, so-called Nox shown in Figure 27 and the combination property of CO are defined as under the situation of Nox and CO decline, and combination property improves.Therefore, the situation that both sides increase among Nox and the CO not only is even if under the situation that the either party increases, combination property also descends.
The invention provides a kind of boiler, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, in the combustion gas flow direction downstream that described burner produces, outfit makes the additional gas nozzle of described burning gases completing combustion, so that fuel secondary firing, it is characterized in that: the described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the contracted flow portion that the outer radial air ejiction opening of outfit air flow circuit dwindles, in the inside of described main additional gas nozzle, have the parts of the minimum flow path area of the described contracted flow of regulation portion.Promptly, because the flow velocity of air is stipulated by the area of contracted flow portion split shed area least part in the contracted flow portion, so have the parts of the minimum flow path area of regulation contracted flow portion by inside, can utilize the air capacity of the area of leading section of these parts and main additional gas nozzle to set the flow velocity of contracted flow portion arbitrarily at main additional gas nozzle.
In addition, the invention provides a kind of boiler, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, in the combustion gas flow direction downstream that described burner produces, outfit makes the additional gas nozzle of described burning gases completing combustion, so that fuel secondary firing, it is characterized in that: the described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the contracted flow portion that the outer radial air ejiction opening of outfit air flow circuit dwindles, described main additional gas nozzle is by 1 nozzle, 3 nozzles formations that are arranged at 2 nozzles in 1 nozzle outside and are arranged at 2 nozzle outsides, described 3 nozzles have the velocity component of center position towards nozzle center's axle from the air stream of described 3 nozzles ejection.Like this, have the velocity component of center position,, also can adjust the intensity of contracted flow even if be not equipped with the movable member of parts of the minimum flow path area of regulation contracted flow portion by air stream from the ejection of 3 nozzles.
In addition, the invention provides a kind of boiler, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, in the combustion gas flow direction downstream that described burner produces, outfit makes the additional gas nozzle of described burning gases completing combustion, so that fuel secondary firing, it is characterized in that: the described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the external diameter that is equipped with air flow circuit is towards contracted flow portion that the air ejiction opening dwindles, described main additional gas nozzle is by 1 nozzle, 3 nozzles formations that are arranged at 2 nozzles in 1 nozzle outside and are arranged at 2 nozzle outsides, described 3 nozzles are towards nozzle center's axle, have the velocity component of center position from the air stream of described 3 nozzles ejection, described 1 nozzle and described 2 nozzles provide air with the direct flow or the stream that circles round.As shown in Figure 5, have the velocity component of center position from the air stream of 3 nozzles ejection, in the outlet of 2 nozzles, 3 air stream and 2 air stream interflow flow into burner hearth internal combustion space.In addition, the emission direction of 2 ejections is parallel to the jet flow central shaft.Therefore, by the air capacity of suitable high speed, can adjust the intensity of contracted flow from 2 nozzles and 3 nozzle ejections.In addition, the ash of fusion is attached near the water pipe of air port outlet in high-temperature combustion gas, when forming clinker, hour by adjusting the air capacity of 2 air and 3 air, clinker is peeled off at clinker.
The invention provides a kind of boiler, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, in the combustion gas flow direction downstream that described burner produces, outfit makes the additional gas nozzle of described burning gases completing combustion, so that fuel secondary firing, it is characterized in that: the described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the contracted flow portion that the outer radial air ejiction opening of outfit air flow circuit dwindles, described additional gas nozzle is arranged to secondary.That is, in being arranged to the additional gas nozzle of secondary, possess the main additional gas nozzle that is equipped with contracted flow portion at the upstream side (first order) of combustion gas flow direction, (second level) is equipped with auxilliary additional gas nozzle in the downstream.Like this, because auxilliary additional gas nozzle is provided with also near the downstream than main additional gas nozzle, so as shown in figure 14, owing to the heat release to hearth wall, it is lower than 1500 degree that near the ambient air temperature degree the auxilliary additional gas nozzle becomes.Therefore, even if the ambient air temperature degree is owing to the air velocity from auxilliary additional gas nozzle ejection changes, also owing to the influence that the Nox generation is caused is little, so can reduce the Nox that from burner hearth integral body, produces by being reduced near the Nox that produces the main additional gas.
In addition, the invention provides a kind of boiler, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, in the combustion gas flow direction downstream that described burner produces, outfit makes the additional gas nozzle of described burning gases completing combustion, so that fuel secondary firing, it is characterized in that: the described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the contracted flow portion that the outer radial air ejiction opening of outfit air flow circuit dwindles, on the relative position of burner hearth antetheca and burner hearth rear wall, respectively dispose a plurality of described main additional gas nozzles and other auxilliary additional gas nozzle respectively.Like this, by with the additional gas nozzle arrangement on the relative position of burner hearth antetheca and burner hearth rear wall, can make near the central authorities of air stream in burner hearth of this additional gas nozzle ejection and impact the mixing that promotion is burnt.
In addition, a kind of boiler is provided among the present invention, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, in the combustion gas flow direction downstream that described burner produces, outfit makes the additional gas nozzle of described burning gases completing combustion, so that fuel secondary firing, it is characterized in that: the described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the contracted flow portion that the outer radial air ejiction opening of outfit air flow circuit dwindles, the described auxilliary additional gas nozzle of configuration directly over described main additional gas nozzle.Like this, by the auxilliary additional gas nozzle of configuration directly over main additional gas nozzle, can dispose auxilliary additional gas nozzle easily.
Claims (19)
1. the additional gas nozzle of a secondary firing usefulness boiler is characterized in that,
Has the stream external diameter towards contracted flow portion that the air ejiction opening that air is offered boiler dwindles with change the flow path cross sectional area modifier of the flow path cross sectional area of described contracted flow portion.
2. the secondary firing according to claim 1 additional gas nozzle of boiler is characterized in that,
Described flow path cross sectional area modifier is arranged on the inside of described additional gas nozzle.
3. the secondary firing according to claim 1 additional gas nozzle of boiler is characterized in that,
Described flow path cross sectional area modifier can be: stipulate that the parts of the minimum flow path area of described contracted flow portion are arranged on the inside of described additional gas nozzle, move the flow path cross sectional area that described parts change described contracted flow portion by longshore current road direction.
4. the secondary firing according to claim 1 additional gas nozzle of boiler is characterized in that,
The structure of described flow path cross sectional area modifier is: stipulate that the parts of the minimum flow path area of described contracted flow portion are arranged on the inside of described additional gas nozzle, described parts are the structures that can exchange separately, by exchanging the flow path cross sectional area that described parts change described contracted flow portion.
5. it is characterized in that with the additional gas nozzle of boiler according to any described secondary firing in claim 3 or 4,
The parts of stipulating the minimum flow path area of described contracted flow portion are structures that external diameter diminishes gradually towards the air ejiction opening.
6. the secondary firing according to claim 3 additional gas nozzle of boiler is characterized in that,
The moving range of the parts of minimum flow path area when being benchmark with the flow direction that is flowing in the air in the described additional gas nozzle, the described contracted flow of regulation portion begins to stop to the position that is positioned at than the more close flow direction downstream, starting position of described contracted flow portion for be positioned at position than the more close flow direction upstream side in starting position of described contracted flow portion from its leading section.
7. secondary firing formula boiler has: burner hearth, make fuel and air burning, and utilize the heat energy of burning gases that steam is produced; Burner is arranged on the gas flow direction upstream side of described burner hearth, makes fuel combustion under the condition of lack of air; With the additional gas nozzle, in the gas flow direction downstream of described burner hearth, be arranged at the downstream of described burner, the air that burning gases completing combustion is used is provided, it is characterized in that,
In described burner hearth, a plurality of additional gas nozzles are set, this additional gas nozzle has the stream external diameter towards contracted flow portion that the air ejiction opening that air is offered boiler dwindles with change the flow path cross sectional area modifier of the flow path cross sectional area of described contracted flow portion.
8. boiler, under the state that is provided in lack of air on the hearth wall, make the burner of fuel combustion, the flow direction downstream of the burning gases that produce at described burner, outfit makes the additional gas nozzle of described burning gases completing combustion, so that described burning gases secondary firing, it is characterized in that
The described additional gas nozzle of multistage configuration on the combustion gas flow direction, be equipped with to adjust the device of the air capacity of the main additional gas nozzle that is arranged on upstream, in described main additional gas nozzle, the external diameter that is equipped with air flow circuit is towards contracted flow portion that the air ejiction opening dwindles.
9. boiler according to claim 8 is characterized in that,
In the inside of described main additional gas nozzle, have the parts of the minimum flow path area of the described contracted flow of regulation portion.
10. boiler according to claim 8 is characterized in that,
Described main additional gas nozzle is made of 1 nozzle, 3 nozzles being arranged at 2 nozzles in 1 nozzle outside and being arranged at 2 nozzle outsides, described 3 nozzles have the velocity component of center position towards nozzle center's axle from the air stream of described 3 nozzles ejection.
11. boiler according to claim 10 is characterized in that,
Described 1 nozzle and described 2 nozzles provide air with the direct flow or the stream that circles round.
12. boiler according to claim 8 is characterized in that,
Possess: the additional gas nozzle air amount governor motion of regulating the total amount of the air that offers described main additional gas nozzle and other auxilliary additional gas nozzle; Offer the air capacity of described main additional gas nozzle and the mechanism of the ratio of the air capacity of other auxilliary additional gas nozzle with adjusting.
13. boiler according to claim 8 is characterized in that,
Described additional gas nozzle is arranged to secondary.
14. boiler according to claim 8 is characterized in that,
On the relative position of burner hearth antetheca and burner hearth rear wall, dispose a plurality of described main additional gas nozzles and other auxilliary additional gas nozzle respectively.
15. boiler according to claim 14 is characterized in that,
The described auxilliary additional gas nozzle of configuration directly over described main additional gas nozzle.
16. boiler according to claim 14 is characterized in that,
Downstream between described main additional gas nozzle disposes described auxilliary additional gas nozzle.
17. boiler according to claim 14 is characterized in that:
In the boiler side walls side, dispose described auxilliary additional gas nozzle.
18. the combustion method of a boiler, this boiler makes the burner of fuel combustion under the state that is provided in lack of air on the hearth wall, the flow direction downstream of the burning gases that produce at described burner, outfit makes the additional gas nozzle of described burning gases completing combustion, so that described burning gases secondary firing, it is characterized in that
The described additional gas nozzle of multistage configuration on the combustion gas flow direction, adjustment is arranged on the air velocity of the main additional gas nozzle of upstream, utilization is equipped with the boiler of the external diameter of air flow circuit towards the contracted flow portion that the air ejiction opening dwindles in described main additional gas nozzle, carry out the secondary firing of fuel, at this moment, adjustment offers the air capacity of main additional gas nozzle, adjusts the ejection flow velocity.
19. the combustion method of a boiler, this boiler makes the burner of fuel combustion under the state that is provided in lack of air on the hearth wall, the flow direction downstream of the burning gases that produce at described burner, outfit makes the additional gas nozzle of described burning gases completing combustion, so that described burning gases secondary firing, it is characterized in that
The described additional gas nozzle of multistage configuration on the combustion gas flow direction, adjustment is arranged on the air velocity of the main additional gas nozzle of upstream, utilization is equipped with the boiler of the external diameter of air flow circuit towards the contracted flow portion that the air ejiction opening dwindles in described main additional gas nozzle, carry out the secondary firing of fuel, at this moment, the air capacity that offers burner is remained in the prescribed limit of Nox generation minimizing, adjustment offers the distribution of the air capacity of main additional gas nozzle and other auxilliary additional gas nozzle, adjusts the ejection flow velocity of described main additional gas nozzle.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004318996A JP4394561B2 (en) | 2004-11-02 | 2004-11-02 | After-air nozzle for two-stage combustion boiler and two-stage combustion boiler using the same |
| JP2004318996 | 2004-11-02 | ||
| JP2004356394 | 2004-12-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1782499A true CN1782499A (en) | 2006-06-07 |
Family
ID=36726494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200510117514 Pending CN1782499A (en) | 2004-11-02 | 2005-11-02 | After-air nozzle for two-stage combustion boiler, and a two-stage combustion boiler, and combustion method using the same |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4394561B2 (en) |
| CN (1) | CN1782499A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110966590A (en) * | 2019-12-04 | 2020-04-07 | 国网浙江省电力有限公司电力科学研究院 | Primary and secondary air coupling jet system and operation method thereof |
| CN111512089A (en) * | 2017-12-26 | 2020-08-07 | 三菱日立电力系统株式会社 | Solid fuel burner and flame stabilizer for solid fuel burner |
| CN113566198A (en) * | 2021-06-09 | 2021-10-29 | 上海交通大学 | Flameless combustor suitable for variable load and use method thereof |
| CN114922868A (en) * | 2022-07-05 | 2022-08-19 | 兰州理工大学 | Telescopic nozzle jet pump |
| TWI785307B (en) * | 2019-02-13 | 2022-12-01 | 日商三菱動力股份有限公司 | Rear vent hole and combustion device provided therewith |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2645680A1 (en) | 2006-03-14 | 2007-09-20 | Babcock-Hitachi Kabushiki Kaisha | In-furnace gas injection port |
| JP2011058737A (en) * | 2009-09-11 | 2011-03-24 | Babcock Hitachi Kk | Pulverized coal burning boiler |
| JP2018028418A (en) * | 2016-08-19 | 2018-02-22 | 三菱日立パワーシステムズ株式会社 | Solid fuel burner |
-
2004
- 2004-11-02 JP JP2004318996A patent/JP4394561B2/en not_active Expired - Fee Related
-
2005
- 2005-11-02 CN CN 200510117514 patent/CN1782499A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111512089A (en) * | 2017-12-26 | 2020-08-07 | 三菱日立电力系统株式会社 | Solid fuel burner and flame stabilizer for solid fuel burner |
| CN111512089B (en) * | 2017-12-26 | 2022-07-08 | 三菱重工业株式会社 | Solid fuel burner and flame stabilizer for solid fuel burner |
| TWI785307B (en) * | 2019-02-13 | 2022-12-01 | 日商三菱動力股份有限公司 | Rear vent hole and combustion device provided therewith |
| CN110966590A (en) * | 2019-12-04 | 2020-04-07 | 国网浙江省电力有限公司电力科学研究院 | Primary and secondary air coupling jet system and operation method thereof |
| CN110966590B (en) * | 2019-12-04 | 2021-08-03 | 国网浙江省电力有限公司电力科学研究院 | Primary and secondary air coupling jet system and operation method thereof |
| CN113566198A (en) * | 2021-06-09 | 2021-10-29 | 上海交通大学 | Flameless combustor suitable for variable load and use method thereof |
| CN114922868A (en) * | 2022-07-05 | 2022-08-19 | 兰州理工大学 | Telescopic nozzle jet pump |
| CN114922868B (en) * | 2022-07-05 | 2023-12-08 | 兰州理工大学 | Telescopic nozzle jet pump |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4394561B2 (en) | 2010-01-06 |
| JP2006132798A (en) | 2006-05-25 |
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