JP2948519B2 - Low NOx and low CO combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is a suitable for use in a multi-tubular boiler or the like, while suppressing the discharge of production and CO NOx high load combustible low NOx and low CO combustion Summarize <<br/>.

[0002]

2. Description of the Related Art In recent years, boilers have been required to further reduce harmful combustion exhaust gases, particularly NOx and CO, due to environmental pollution problems and the like. Various measures for reducing such harmful combustion exhaust have been proposed, but one of the measures is to place the heat transfer tubes as close to the combustion surface of the burner as possible and place the heat transfer tube group in the combustion flame. In addition, a technique is known in which the generation of thermal NOx is suppressed as much as possible by cooling the flame at the same time as the heat exchange, and high load combustion is realized. However, according to this conventional measure, NO
Although x can be reduced, there is a problem that CO emission becomes high. This is because, for CO, the reaction is frozen by the quenching effect of the combustion flame (including combustion gas) that reduces NOx, and unreacted substances having an equilibrium structure at high temperatures are discharged out of the system as they are. This is considered to be one of the causes. In order to solve this problem, the temperature of the flame should be 1000 ° C. or higher with a cold object placed near or in contact with the flame generated by high load combustion.
A technique has been proposed in which after controlling the temperature to 500 ° C. or lower, the residual CO in the flame is oxidized and converted into CO ₂ in an adiabatic space provided on the downstream side of the cold body.

[0003]

SUMMARY OF THE INVENTION However, this prior art is compared with a low NOx can body of a space-saving multi-tube once-through boiler having the following configuration, that is, a pair of heat transfer tubes parallel to each other. The wall defines a combustion / heat exchange area through which a combustion flame and a combustion gas flow, a combustion burner is arranged on one side of the combustion / heat exchange area, and the exhaust gas is discharged from the other side. When it is applied to a can body having a configuration in which a heat transfer tube group consisting of a number of heat transfer tubes arranged substantially in parallel with each other and at a predetermined interval is arranged as in a combustion flame in a combustion gas, When formed, CO can be reduced, but the generation of NOx increases, resulting in low NO.
There is a problem in that the advantages of the x-can body are lost, and the boiler is no different from a conventional boiler with a non-low NOx specification. Also, if the length of the heat insulating space in the direction of flow of the combustion gas is long, the space saving property is impaired, and the temperature rise of the can body wall defining the heat insulating space becomes large. In order to prevent this temperature rise, it is necessary to install a heat insulating material on the inner surface of the can body wall on the heat insulating space side,
This leads to an increase in equipment cost. In addition, when the heat insulating material is applied, the heat insulating material may fall due to long-term use, and there is a problem in durability and a problem such as a decrease in heat exchange efficiency.

The inventors of the present application have noted the above problems and
It is an object of the present invention to provide a low NOx and low CO combustion apparatus capable of performing high load combustion while suppressing generation of Ox and emission of CO.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention of claim 1 is a fin-like structure for connecting a plurality of heat transfer tubes to adjacent heat transfer tubes. combustion flame by a pair of heat transfer tubes walls forming substantially parallel to each other consisting of a member defining a region where combustion gas flows, the combustion burner is disposed on one side of the zone, the flue gas on the other side the outlet is provided, the spacing of the heat transfer tube group ing of a number of heat transfer tubes disposed at a predetermined interval in substantially parallel, a water pipe immediately before the previous Ki燃 sintered burner and the premix plan combustion burner each other as will be less than 3 times the water tube diameter, the in close proximity to the combustion burner is disposed, and between said the heat transfer tube array in the flow direction of the combustion flame of the heat transfer tube array and the heat transfer tube group of the heat transfer tube wall combustion flame out combustion exhaust gas before Ki燃 sintered burner between heat transfer tubes adjacent rows of tube banks In the one in which the combustion flame passage is formed so as to circulate toward the heat transfer tube row, a heat transfer tube non-existing space is formed in a predetermined heat transfer tube row of the heat transfer tube group, and the heat transfer tube row in which the heat transfer tube non-existing space is formed is adjacent. By not forming a heat transfer tube non-existing space in the heat transfer tube row, the flame temperature is reduced from approximately 1000 ° C. to 1 at a position where the plurality of flame flow passages merge.
3. A low-NOx and low-CO combustion apparatus formed at 300 ° C. and having an extended flame flow passage for obtaining a residence time of the combustion flame and combustion gas in which CO reacts with a reactive group and / or oxygen atom. According to the invention, a combustion flame and an area through which a combustion gas flows are defined by a pair of heat transfer tube walls which are substantially parallel to each other and are formed of a plurality of heat transfer tubes and a fin-shaped member connecting adjacent heat transfer tubes. , the heat transfer tube of the combustion burner is disposed on one side of the area, a flue gas outlet provided on the other side, are arranged in a staggered manner consists of a number of heat transfer tubes disposed at a predetermined interval substantially parallel to each other groups, before distance between the water pipe and the front Ki燃 sintered burner of the preceding Ki燃 sintered burner so is less than 3 times the water tube diameter, and the heat transfer of the heat transfer tube group and the heat transfer tube of the heat transfer tube wall Arrange so that the heat transfer tube adjacent to the heat tube wall is staggered, Combustion flame combustion exhaust gas before Ki燃 sintered burner between the heat transfer tube bank, and between adjacent of the heat transfer tube group in the heat transfer tube array in the flow direction of the combustion flame of the heat transfer tube array and the heat transfer tube group of the heat transfer tube wall In a configuration in which a meandering combustion flame passage is formed so as to flow toward the outlet, a heat transfer tube non-existing space is formed in a predetermined heat transfer tube row of the heat transfer tube group, and a heat transfer tube non-existing space is formed. By not forming a heat transfer tube non-existent space in the heat transfer tube row adjacent to the heat pipe row, the flame temperature is reduced from approximately 1000 ° C. to a position where the plurality of flame flow passages merge.
A low- NOx and low-CO combustion apparatus formed at 1300 ° C. and having an extended flame flow passage for obtaining a residence time of the combustion flame and the combustion gas in which CO reacts with a reactive group and / or an oxygen atom. The invention of claim 3 is based on claim 2,
Heat transfer tube bank in the flow direction of the combustion flame of the heat transfer tube group consists of three columns, the expanded flame passage by forming a heat transfer tube absence space in the third heat transfer tube portions on both sides of the column odor Te from combustion burner side A low NOx and low CO combustion device is characterized in that it is formed. The invention of claim 4 is the invention according to claim 2, wherein the heat transfer tube group is composed of three rows arranged in the flow direction of the combustion flame. characterized in third and fourth low-NOx and low CO combustion apparatus characterized by the formation of the expanded flame passage by forming a heat transfer tube absence space the heat transfer tube portion from the combustion burner side Te is there.

[0006]

SUMMARY OF] According to the invention of claim 1, the combustion flame from the combustion burner that is cooled by heat transfer tube group in the vicinity, the generation of NOx is reduced, NOx is an enlarged flame passage
CO is converted to CO ₂ and CO emission is reduced while the generation of CO is suppressed. That is, in the expanded flame passage,
The combustion flame and combustion gas oxidize the residual CO to produce CO2
_{Since the} temperature is sufficient to convert to ₂ and the residence time of the combustion flame and combustion gas is obtained in this local passage, the residual CO is oxidized and converted to CO ₂ to reduce CO and expand. Since the combustion flame and the combustion gas temperature in the flame passage are in the temperature range where the generation of thermal NOx is small, N
Ox generation is suppressed. In addition, since the expanded flame passage is sandwiched on both sides by the heat transfer tube rows, that is, the heat transfer tubes are arranged on both sides of the expanded flame passage, no local high-temperature portion is generated, and the generation of NOx is suppressed while reducing CO. Is done. Furthermore,
When the combustion flame passage is formed in a meandering shape, the combustion flame and the combustion gas flowing through the different meandering flame flow passages join and mix in the expanded flame passage. Unreacted CO and reactive active group (OH)
And / or aggressive contact with oxygen atoms (O) results in a large CO reduction despite the relatively small space.

[0007]

1 to 4 show an embodiment of an apparatus for realizing a low NOx and low CO combustion method according to the present invention. Referring to FIG. 1, (K) is a rectangular can body of a multi-tube once-through boiler, and (10) (10) are a plurality of heat transfer tubes (11) (11). Combustion and heat exchange areas
The heat transfer tube walls defining (N), (20), (20) are substantially parallel to each other and are arranged between the heat transfer tube walls (10) (10) at predetermined intervals. The heat transfer tube group in the combustion / heat exchange area is constituted by the substantially vertical heat transfer tubes. (40) is a combustion burner arranged at one side opening between the heat transfer tube walls (10) and (10), and (C) is another side opening between the heat transfer tube walls (10) and (10). 4 shows a combustion exhaust gas outlet formed in the section. This combustion exhaust gas outlet may be provided at the end of the combustion / heat exchange section (N) on the side opposite to the burner, and can be formed, for example, by removing and opening a part of the heat transfer tube wall (10). Heat transfer tube (20)
In (20), the heat transfer tube rows (X), (Y), and (Z) in the combustion flame flow direction have the following tube numbers (X1) (X2) ..., (Y1) (Y2) ..., (Z1) (Z2)…
The heat transfer tube rows (A) and (B) of the heat transfer tubes (11) and (11) are each given a tube number (A1) (A2)... (B1) (B2). I do. With reference to FIGS. 2 and 3, heat transfer tubes (11) (11)... Constituting the heat transfer tube walls (10) (10) and heat transfer tubes (10) and (10) disposed between the heat transfer tube walls (10) (10) The upper and lower ends of (20), (20) are connected to an upper header (13) and a lower header (14), respectively.

In this embodiment, the heat transfer tube wall (10) has a plurality of heat transfer tubes (11) arranged in tandem at appropriate intervals, and a gap between the heat transfer tubes (11) (11). The heat transfer tubes (11)
(11) A flat fin-shaped member extending along the axial direction of
(12) (12) ... The structure is closed by these heat transfer tube walls (1
0) and (10) are arranged at appropriate intervals so as to be substantially parallel to each other.

A plurality of heat transfer tubes (20) (20) arranged between the heat transfer tube walls (10) (10) are appropriately arranged, for example, three rows (X) (Y) as shown in the figure. (Z), and the heat transfer tubes in adjacent rows including the heat transfer tubes (11), (11) ... of the heat transfer tube walls (10), (10) are staggered. . In addition, each heat transfer tube (11) (11) ..., (20) serving as a flow path for combustion flame and combustion gas
(20) ... The gap (interval) between them is preferably set to be approximately equal to or less than the diameter of each heat transfer tube (11) (20). Even if all these gaps are the same, Even if they are different from each other, they may be within the above-mentioned conditions.

Among the above heat transfer tubes (20), a position in a specific temperature range suitable for reducing CO while suppressing the generation of NOx is determined in advance by experiments, and no heat transfer tube exists at this position. The can body of FIG. 1 having the space (VX3) (VZ3) is configured. In the embodiment, the combustion flame (combustion gas) temperature is about 10 in a specific temperature range.
Using a can body (K ′) having a heat transfer tube arrangement shown in FIG. 12 and a boiler apparatus shown in FIG. 5, the position of the specific temperature area was determined by experiments using a temperature range of 00 ° C. to 1300 ° C. In FIG. 12, curve 1 is a temperature curve in the flow path 1 and curve 2 is a temperature curve in the flow path 2. From FIG. 12, in this embodiment, the heat transfer tube non-existent space (VX3) (VZ3) is formed at the position of the heat transfer tube (X3) of the heat transfer tube array (X) and the heat transfer tube (Z3) of the heat transfer tube array (Z). The heat transfer tube row (X) and the heat transfer tube row (Y) adjacent to the heat transfer tube row (Z) do not have a heat transfer tube non-existent space, and are continuous with the heat transfer tube non-existent space (VX3) (VZ3). Does not form a non-existent space. This heat transfer tube non-existing space (VX
3) Although (VZ3) is relatively narrow (the width is twice the width of the gap between heat transfer tubes and the cross-sectional area of the heat transfer tubes), it is a local area that causes combustion gas and flame to stagnate. It functions as a stagnation space and reacts the residual CO generated in the upstream high-temperature combustion flame region with the reactive group to oxidize it, thereby reducing CO. In addition, since the flame temperature is relatively low, the generation of NOx can be suppressed. . According to the calculation, the residence time of the combustion gas in the non-existent space (VX3) (VZ3) is calculated as input: 8.66Nm ³ /
h, channel width: 0.0615m, channel cross section: 0.0246m ² , combustion gas temperature: 1200 ° C, it is estimated to be about 9.5msec. In the embodiment of FIG. 1, the heat transfer tubes (A3), (A4), (X4), (Y3), (Y2), (X2), and the heat transfer tubes around the heat transfer tube non-existent spaces (VX3) and (VZ3), respectively.
(Y2) (Y3) (Z4) (B4) (B3) (Z2)
(VX3) and (VZ3) are configured to prevent the generation of high-temperature portions and suppress the generation of NOx, and to maintain good space saving and thermal efficiency. On the upstream side of the heat transfer tube non-existent space (VX3) (VZ3), heat transfer tubes (11), (11) ... (heat transfer tube row on the heat transfer tube wall)
And each of the heat transfer tubes (11) (1) between the heat transfer tubes (20) (20) ... (the heat transfer tube rows of the heat transfer tube group) and between the heat transfer tube rows of the heat transfer tubes (20) (20) ...
1)…, (20) (20)… Four meandering flame flow passages (R1) (R2) (R3) (R4) consisting of mutual gaps are formed, and the heat transfer tube non-existent space (VX3) ( VZ3) has two flame passages (R1) (R2), (R
3) formed at the junction of (R4) and the expanded flame flow passage (R13) (R3
4) is configured. As a result, the heat transfer tube non-existing space (VX3)
In (VZ3), the combustion gases flowing through different flame flow passages are mixed, and the mixing allows the unreacted CO to positively contact with the reactive groups and / or oxygen atoms, and the high temperature retention of the combustion gas. The configuration is such that effective CO reduction is performed by lengthening the time.

[0011] The combustion burner (40) is preferably a premixed planar combustion burner, for example, a corrugated plate (41) and a flat plate (42) alternately stacked to form a large number of small fuel injection holes (43). A premixing type flat combustion burner is used in which the combustion surface is divided into right and left by a frame dividing plate (44), but a ceramic plate burner having a large number of small holes for ejecting a premixed gas may be used, It is also possible to use various burners other than the vaporized combustion oil burner. The gap with the heat transfer tube (20) located immediately before the combustion burner (40) is set to a predetermined distance, for example, approximately equal to or less than three times the diameter of the heat transfer tube (20), and The distance is set as a reference, such as the heat transfer tube wall (10).

In the above configuration, the combustion flame from the combustion burner (40) continues to burn even in the interstitial spaces between the heat transfer tubes (11) (11)..., (20) (20). It flows through the combustion flame flow passages (R1) (R2) (R3) (R4) toward the exhaust gas outlet (C), during which the heat transfer tubes (11) (11) ..., (20) (2
0) to transfer heat (heat exchange) to the combustion burner
(40) and the heat transfer tube (20) immediately before and each heat transfer tube (11) (10) ..., (20)
(20) Since the gap is set to be narrow as described above, the combustion flame and combustion gas flow toward the combustion exhaust gas outlet (C) while maintaining a high flow velocity, and have an extremely high contact heat transfer rate. Cooled.

The combustion flame and the combustion gas having passed through the flame flow passages (R1), (R2), (R3), and (R4) merge in the expanded flame passages (R12) and (R34). Here, the temperature of the combustion flame and combustion gas is about 100
Since the temperature is 0 ° C. to 1300 ° C., the generation of NOx is suppressed, and the CO generated in the upstream high-temperature combustion flame region becomes a reactive active group (radical) due to the high-temperature retention effect of the combustion gas.
And / or reacts with oxygen atoms to oxidize and reduce CO.
In addition, heat transfer tubes are arranged around each heat transfer tube non-existent space (VX3) (VZ3), that is, the temperature rise is about 50 ° C due to the presence of a heat transfer surface (heat transfer tube) at a predetermined distance. , The rise in the reaction temperature is suppressed, and the generation of NOx is suppressed.
Further, in each heat transfer tube non-existent space (VX3) (VZ3), the combustion gas flowing through the different flame flow passages (R1) (R2) and (R3) (R4) collide and mix, and the unreacted CO And the active group and / or oxygen atoms are positively contacted with each other, and the high-temperature residence time of the combustion gas becomes longer due to the generation of a vortex due to mixing,
CO is significantly reduced.

The above-mentioned effect has been confirmed by experiments, and will be described below. The apparatus used in the experiment is shown in FIG. 4, and has a can body (K) having the structure shown in FIGS. 1-3, a duct (D) for supplying a premixed gas to the burner (40), a wind box (W), and flue gas. Economizer (feed preheater) (E), steam extraction pipe (J), duct (D) connected to outlet (C)
Consists of a blower (not shown), exhaust stack (H), wire mesh (M1) (M2) provided in duct (D) for better mixing, and fuel gas using propane duct (D). Site (N)
Supplied from The steam pressure is 4.5-5.0 kg / cm ² G
And the excess air ratio was changed by adjusting the rotation speed of the blower, and the NOx and CO concentrations discharged at each oxygen concentration were measured.

FIGS. 6 and 7 show measurement results of the embodiment (an example in which a heat transfer tube non-existing space is formed). As can be seen from the results, as compared with the measurement results using the conventional can body (K ′) not forming the heat transfer tube non-existent space shown in FIGS.
NOx hardly changes, and the CO concentration is 24 to
9 ppm to 10 ppm (all O
₂₀ % conversion) and a 63% reduction effect were obtained. Also, if the range of this low CO level is, for example, the threshold value in the conventional example as a threshold value, it is O ₂ 2.5 to 7.2%, which extends to almost the entire measurement range, and a slightly poor combustion state. This also means that the emission concentration of CO is kept low.

FIG. 8 shows the reaction rates of NOx and CO.
It can be seen that the decrease of O is sharply reduced in the heat transfer tube non-existing space. FIG. 11 is a characteristic diagram of a conventional example corresponding to FIG.

The reason why the specific temperature range of the heat transfer tube is set to approximately 1000 ° C. to 1300 ° C. in the above embodiment is also supported by the following reasons. That is, the low temperature of CO (150
If the oxidation reaction at 0 ° C. or lower follows the following equation, then -d
[CO] /dt=1.2×10 ¹¹ [CO] [O ₂ ] ^0.3 [H ₂ O]
^0.5 exp ^{(-8050 / T)}
As shown in FIG. 3, CO can be easily reduced structurally by forming a heat transfer tube non-existent space in a high temperature portion as much as possible. However, according to FIG. 14 showing the relationship between the NOx reaction rate coefficient and the combustion gas temperature, if the heat transfer tube non-existing space is formed at a temperature of 1400 ° C. or higher, more thermal NOx is generated due to the longer high-temperature residence time. Therefore, it is necessary to avoid this temperature zone.

The present invention is not limited to the above embodiment. The present invention is also applicable to a device in which the burners and the heat transfer tubes are arranged not in the vertical direction but in the horizontal direction. In addition, FIG. 15
As shown in (1), the heat transfer tube non-existing space may have a shape extending in the flow direction of the combustion gas. Further, in the above embodiment, the heat transfer tubes (11) and the heat transfer tubes (20) are arranged around the heat transfer tube non-existent space, but when the number of rows of the heat transfer tubes (20) is large, the heat transfer tubes (2
Only 0) may be arranged. Further, a heat transfer tube may be inserted into a portion indicated by (Y0) in FIG. 1 so as to further reduce NOx. Further, the present invention is applicable to a multi-tube hot water boiler, a water tube boiler, and the like.

[0019]

As described above, according to the present invention, the quenching is performed in the combustion flame heat transfer tube bank by the premixed combustion burner,
Although the generation of NOx is reduced, CO is generated during the cooling. However, expanding the flame passage of the present invention, the residual CO generated during cooling so as to obtain a residence time to shift to CO ₂ by oxidation reaction, and a temperature range of generating less heat transfer tube group thermal NOx Since the combustion flame and the combustion gas flowing into the expanded flame passage are formed in the expanded flame passage, while the generation of NOx is suppressed in the expanded flame passage, the combustion flame,
Residual CO in the combustion gas is discharged by the oxidation reaction was transformed into CO ₂ CO is reduced by staying in the combustion flame, the combustion gases. In addition, since the expanded flame passage is sandwiched on both sides by a heat transfer tube row, that is, heat transfer tubes are arranged on both sides of the expanded flame passage, it does not become an adiabatic space where a local high-temperature portion is generated, and NOx is generated while reducing CO while reducing CO. Can be suppressed. In addition, since the enlarged flame passage is locally formed to be narrow, space saving,
A can body having excellent heat efficiency can be provided. Furthermore, by making the arrangement of the heat transfer tube groups staggered and making the flame passage meandering, when the combustion flame and the combustion gas flowing through the different meandering flame flow passages join in the expanded flame passage and mix, The mixing and retention effects are large, and the unreacted CO is positively brought into contact with the reactive groups (OH) and / or oxygen atoms (O). As a result, a large amount of CO is reduced in a relatively small space. . Also, there is an effect that the disadvantage of the conventional example in which the heat insulating space is formed can be eliminated. Thus, according to the present invention, low NOx and low CO using a premixed combustion burner of great industrial value
A combustion method and apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating the schematic structure of a can according to one embodiment of the present invention.

FIG. 2 is a side view of the can body of the embodiment with the can body cover removed.

FIG. 3 is a sectional view of a main part of the can body of the embodiment.

FIG. 4 is a perspective view of the burner of the embodiment.

FIG. 5 is an external perspective view of the entire apparatus according to the embodiment of the present invention.

FIG. 6 is a graph showing NOx and CO emission characteristics of the can of the embodiment.

FIG. 7 is a diagram showing NO when the can of the embodiment is differently input.
It is a x, CO discharge characteristic diagram.

FIG. 8 is a graph showing NOx generation, CO reduction, and reaction rate characteristics in a can of the embodiment.

FIG. 9 is a graph showing NOx and CO emission characteristics of a conventional can body.

FIG. 10: NO at different input of the can of the conventional example
It is a x, CO discharge characteristic diagram.

FIG. 11 is a characteristic diagram of NOx generation, CO reduction, and reaction rate in a can of a conventional example.

FIG. 12 is a diagram showing a combustion gas temperature characteristic in a can in a conventional example.

FIG. 13 is a characteristic diagram showing the relationship between the CO oxidation reduction reaction rate and the combustion gas temperature.

FIG. 14 is a characteristic diagram showing a relationship between a NOx reaction rate coefficient and a combustion gas temperature.

FIG. 15 is a plan view showing a schematic structure of a can according to another embodiment of the present invention.

[Explanation of symbols]

 (10)… heat transfer tube wall (11)… heat transfer tube (12)… fin-shaped member (20)… heat transfer tube (40)… combustion burner (C)… combustion exhaust gas outlet (VX3) (VZ3) (VY3) ( VX4) (VZ4)… Heat transfer tube non-existing space (R1) (R2) (R3) (R4)… Flame flow passage (R12) (R34)… Expanded flame passage

Continuation of the front page (72) Inventor Kazuhiro Ikeda 7 Horie-cho, Matsuyama-shi, Ehime Miura Industrial Co., Ltd. Examiner Toshifumi Suzuki (56) References JP-A-4-356602 (JP, A) JP-A-60- 78247 (JP, A) Hikaru Hei 2-62201 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F22B 21/04

Claims (4)

(57) [Claims] A pair of substantially parallel heat transfer tube walls, each of which is composed of a plurality of heat transfer tubes and a fin-shaped member connecting adjacent heat transfer tubes, defines an area through which a combustion flame and a combustion gas flow. and a combustion burner disposed on one side of the area, provided the flue gas outlet on the other side, the heat transfer tube group ing of a number of heat transfer tubes disposed at a predetermined interval in substantially parallel to each other,
And the interval between the water pipe and the front Ki燃 sintered burner immediately before the previous Ki燃 sintered burner is equal to or less than 3 times the water tube diameter, the in close proximity to the combustion burner is disposed, the heat transfer tube array of the heat transfer tube wall combustion and as combustion flame before Ki燃 sintered burner between and between heat transfer tubes adjacent rows of the heat transfer tube group in the heat transfer tube array in the flow direction of the combustion flame of the heat transfer tube group flows toward the flue gas outlet In the case where a flame passage is formed, a heat transfer tube non-existing space is formed in a predetermined heat transfer tube row of the heat transfer tube group, and a heat transfer tube row is adjacent to the heat transfer tube row in which the heat transfer tube non-existing space is formed. By not forming the non-existing space, the flame temperature is increased from approximately 1000 ° C. to 130 ° at the position where the plurality of flame flow passages join.
A low NOx and low CO combustion apparatus characterized by forming an expanded flame flow passage at 0 ° C. and obtaining a residence time of the combustion flame and combustion gas in which CO reacts with a reactive group and / or an oxygen atom. 2. An area in which a combustion flame and a combustion gas flow are defined by a pair of heat transfer tube walls which are substantially parallel to each other and are composed of a plurality of heat transfer tubes and a fin-like member connecting adjacent heat transfer tubes. and, heat the combustion burner disposed on one side of the area, a flue gas outlet provided on the other side, are arranged in a staggered manner it consists of a number of heat transfer tubes disposed at a predetermined interval substantially parallel to each other the heat pipe group, before water pipe just before the Ki燃 grilled burner and before Symbol
As the distance between the combustion burner so that the following three times the water tube diameter, and the heat transfer tubes adjacent said heat transfer tube wall of the heat transfer tube group and the heat transfer tube of the heat transfer tube wall is staggered placed, the combustion of pre Ki燃 sintered burner between and between heat transfer tubes adjacent rows of the heat transfer tube group in the heat transfer tube array in the flow direction of the combustion flame of the heat transfer tube array and the heat transfer tube group of the heat transfer tube wall In a meandering combustion flame passage formed so that a flame flows toward a combustion exhaust gas outlet, a heat transfer tube non-existing space is formed in a predetermined heat transfer tube row of the heat transfer tube group, and a heat transfer tube non-existing space is formed. By not forming a heat transfer tube non-existent space in the heat transfer tube row adjacent to the heat transfer tube row in which the flame is formed, the flame temperature is increased from approximately 1000 ° C. to 1300 ° C. at a position where the plurality of flame flow passages merge.
And an expanded flame flow passage for obtaining a residence time of the combustion flame and combustion gas in which CO reacts with a reactive group and / or an oxygen atom.
Combustion equipment. 3. The heat transfer tube group according to claim 2, wherein the heat transfer tube group has three heat transfer tube rows in the flow direction of the combustion flame.
Third low NOx and low CO combustion apparatus characterized by the formation of the expanded flame passage heat transfer tube portion by forming the heat transfer tube absence space from the combustion burner side Te. 4. The method of claim 2, consists of three columns tube banks are arranged in the flow direction of the combustion flame, the heat transfer tube absence from combustion burner side in the third and fourth of the heat transfer tube portion Te sides of the column odor A low NOx and low CO combustion apparatus characterized by forming an expanded flame passage by forming a space.