JP2019100600A - Diffusion combustion burner - Google Patents

Abstract

To provide a diffusion combustion burner securing ignition stability and combustion stability even when a fuel gas including hydrogen as a fuel of high combustion speed is combusted.SOLUTION: The diffusion combustion burner comprises a micro fuel head 1 injecting a fuel gas including hydrogen upward, and a micro air head 2 injecting air upward. The micro fuel head 1 and the micro air head 2 are columnar tube bodies having the same central axis, an inner diameter of the micro fuel head 1 is 2 mm or less, and an inner diameter of the micro air head 2 is larger than an outer diameter of the micro fuel head 1. A plurality of combinations of the micro fuel heads 1 and the micro air heads 2 disposed with positional relationships in which an upper end of the micro air head 2 is flush with a top face of a housing or projected above the same, and an upper end of the micro fuel head 1 is projected above the upper end of the micro air head 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-premixed type diffusion combustion burner which burns fuel gas containing hydrogen as fuel.

A heating furnace is a foundation that supports the production process of automobiles, ceramics, food and the like, but as its fuel gas, it is common to use city gas such as methane.
On the other hand, there is a demand that hydrogen fuel be used for a heating furnace in order to reduce carbon dioxide emissions.

  Therefore, a burner that uses hydrogen as a fuel is considered as a fuel that does not emit carbon dioxide, but when using a burner that uses hydrogen as a fuel in a heating furnace, a burner that usually has a large combustion load (fuel input amount) Is installed and operated in several places in the heating furnace. Therefore, there is a limit in controlling the temperature distribution and the combustion atmosphere of the entire heating furnace, and it is difficult to control them arbitrarily.

  The hydrogen flame is a non-volatile flame (a flame that is almost invisible), the radiation effect is extremely small, and the inside of the furnace is heated by convective heating with hot air, but as described above, the burner with a large combustion load is heated When installed in several places of the furnace, it did not have a structure that takes advantage of the feature of heating the inside of the furnace by convection heating with hot air.

Furthermore, since hydrogen has a wide burning range and a high burning rate, there is a problem that it is easy to flash back in a premix type burner, and at present it has not been put to practical use.
As a burner which solves such a problem, for example, Patent Document 1 describes a hydrogen surface combustion burner of a premix type which is hard to backfire, in which a high temperature resistant porous member is stretched on one side to make a combustion surface. ing.

Japanese Patent Laid-Open No. 2000-18525

  However, in the case of burning a fuel gas containing hydrogen as a fuel, the hydrogen gas has a fast burning rate, so even if a burner as shown in Patent Document 1, for example, is used, a non-premixed type diffusion combustion burner There is a problem that it is difficult to secure such ignition stability and combustion stability.

  The present invention has been made to solve the above problems, and secures the ignition stability and the combustion stability even when the fuel gas containing hydrogen, which is a fuel with a high combustion rate, is burned. It is an object of the present invention to provide a diffusion combustion burner.

  In order to achieve the above object, the present invention relates to a diffusion combustion burner for burning a fuel gas containing hydrogen as a fuel, wherein the diffusion combustion burner is provided in its interior with a fuel chamber separated by an isolation layer. An air chamber is provided, and a fuel introduction pipe for externally supplying a fuel gas containing hydrogen is connected to the fuel chamber, and an air for externally supplying air necessary for combustion is connected to the air chamber. An inlet pipe is connected, and a micro fuel head for injecting a fuel gas containing hydrogen from the fuel chamber above the upper surface of the housing, and the air from the air chamber above the surface of the housing The micro fuel head and the micro air head are columnar tubes having the same central axis, and the inner diameter of the micro fuel head is 2 mm. The inside diameter of the micro air head is greater than the outside diameter of the micro fuel head, the top end of the micro air head projects flush with or above the top surface of the housing, and The upper end of the micro fuel head is characterized by having a plurality of combinations of the micro fuel head and the micro air head disposed in a positional relationship in which the upper end projects above the upper end of the micro air head.

  According to the diffusion combustion burner of the present invention, since the upper end of the micro fuel head protrudes above the upper end of the micro air head, not only the flame is stabilized (the ignition stability and the combustion stability can be ensured), The burnout of the head as a part can be prevented. Further, by setting the inner diameter of the micro fuel head to 2 mm or less, a large number of sets of the micro fuel head and the micro air head can be arrayed, and thus it is possible to burn in an array shape, so uniform heating can be achieved. it can.

FIG. 2 is a view showing an example of an appearance configuration of a diffusion combustion burner in Embodiment 1. FIG. 2 is a cross-sectional view showing a part of the internal configuration of the diffusion combustion burner in the first embodiment. It is a top view at the time of seeing the diffusion combustion burner 100 shown in Drawing 1 from the upper part. FIG. 4 is an enlarged view showing the positional relationship between a set of micro fuel heads 1 and micro air heads 2 and the adjacent micro fuel heads 1 and micro air heads 2 in the top view shown in FIG. 3. It is a table showing an experimental result by a distance between a central axis of one set of micro fuel head 1 and micro air head 2 and a central axis of micro fuel head 1 and micro air head 2 adjacent thereto.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
When a burner containing hydrogen as fuel is used in a heating furnace, conventionally, burners (several tens to several thousand kW burners) with large combustion load (fuel input amount) have been installed and operated at several places in the heating furnace. Therefore, there is a limit in controlling the temperature distribution and the combustion atmosphere of the entire heating furnace, and it has been difficult to control arbitrarily. The hydrogen flame is a non-bright flame (a flame that is almost invisible), the radiation effect is extremely small, and the inside of the furnace is heated by convective heating with hot air, but the structure does not take advantage of its features.

Embodiment 1
The first embodiment relates to a non-premixed type diffusion combustion burner which burns a fuel gas containing hydrogen as a fuel.
FIG. 1 is a view showing an example of an appearance configuration of a diffusion combustion burner 100 according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing a part of the internal configuration of the diffusion combustion burner 100 according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the diffusion combustion burner 100 is provided with a fuel chamber 11 and an air chamber 12 which are independent of each other in a housing 10. At this time, the fuel chamber 11 and the air chamber 12 are separated by the isolation layer 13 and have a double structure in which the fuel chamber 11, the isolation layer 13 and the air chamber 12 are sequentially stacked from the bottom.

  Further, a fuel introduction pipe 21 for supplying a fuel gas A containing hydrogen from the outside is connected to the fuel chamber 11, and an air introduction for supplying the air B necessary for combustion from the outside to the air chamber 12 is connected. The pipe 22 is connected. Thus, the fuel gas A is fed into the fuel chamber 11 and the air B is fed into the air chamber 12.

  Furthermore, the micro fuel head 1 for injecting the fuel gas A containing hydrogen from the fuel chamber 11 above the upper surface 3 of the housing 10 and the micro air head 2 for ejecting the air B from the air chamber 12 are provided. The micro fuel head 1 and the micro air head 2 are cylindrical tubes whose central axes are the same. The inner diameter of the micro fuel head 1 is 2 mm or less, and in the first embodiment, 1 mm is used. Further, the inner diameter of the micro air head 2 is larger than the outer diameter of the micro fuel head 1. That is, the micro air head 2 is disposed to surround the micro fuel head 1. In the first embodiment, the outer diameter of the micro fuel head 1 is 1.2 mm, and the inner diameter of the micro air head 2 is 2 mm.

  By arranging in this manner, as shown in FIG. 2, the fuel gas A is injected upward from the hole of the cylindrical tube of the micro fuel head 1, and the air B is the cylindrical tube of the micro air head 2. And the cylindrical tube body of the micro fuel head 1 are injected upward from a toroidal hole. That is, the diffusion combustion burner 100 is a non-premixing type diffusion combustion burner in which the fuel gas A and the air B are separately jetted and the fuel gas A and the air B are finally mixed to burn.

  In the first embodiment, although the micro fuel head 1 and the micro air head 2 are described as cylindrical tubes having the same central axis, they are columnar tubes having the same central axis. If it does, it need not be cylindrical. For example, it may be an elliptic cylindrical shape, a regular hexagonal cylindrical shape, a regular octagonal cylindrical shape, or the like, or a regular hexagonal cylindrical shape or a columnar shape in which the corner in the regular octagonal shape is slightly rounded. Good.

Further, in FIG. 2, the micro air head 2 is disposed so as to protrude slightly above the upper surface 3 of the housing 10 of the diffusion combustion burner 100, but the upper end of the micro air head 2 is of the housing 10. It may be on the same plane as the upper surface 3. On the other hand, the micro fuel head 1 is disposed to project further upward than the micro air head 2.
That is, the upper end of the micro air head 2 protrudes on the same plane as or above the upper surface 3 of the housing 10, and the upper end of the micro fuel head 1 protrudes above the upper end of the micro air head 2.

  This is because, when using fuel gas A containing hydrogen as fuel, hydrogen burns at a high speed, and if the micro fuel head 1 is not further projected, it will immediately disappear even if it gets on, and the flame will not be stable. It is. In addition, since the micro fuel head 1 from which the fuel gas containing hydrogen is ejected protrudes, the air cools, so that the burnout of the head as a component can be prevented.

  Furthermore, in FIG. 2, the lower end of the micro air head 2 has a length to the same position as the lower surface of the upper surface 3 of the casing 10 of the diffusion combustion burner 100 (they are flush). It may project further downward than the lower surface of. Although the micro air head 2 and the upper surface 3 are shown as separate members in FIG. 2, the micro air head 2 and the upper surface 3 may be configured as an integral member.

  Similarly, in FIG. 2, the lower end of the micro fuel head 1 has the same length as the lower surface of the isolation layer 13 (is flush with), but protrudes further downward than the lower surface of the isolation layer 13 It may be Although the micro fuel head 1 and the isolation layer 13 are shown as separate members in FIG. 2, the micro fuel head 1 and the isolation layer 13 may be configured as an integral member.

  Here, an experiment in which a fuel gas containing hydrogen as a fuel is actually burned and the results obtained thereby will be described. In addition, although illustration and detailed description are abbreviate | omitted because it is not directly related to this invention, it experimented also about what kind of influence hydrogen supply and air ratio have on a hydrogen flame. First, it was found that, when the air ratio was kept constant (1.05) and the hydrogen input amount was gradually increased to 0.1 kW to 1.0 kW, the flame extension was gradually increased. Also, assuming that the amount of hydrogen input is constant (in the case of 0.5 kW and 1.0 kW in the case of 0.1 kW), the amount of hydrogen input will be even if the air ratio is gradually increased to 1.05 to 2.0. It was found that the flame extension was also almost the same if. That is, it was obtained that the flame shape of the hydrogen flame can be controlled by adjusting the hydrogen input amount and the air ratio.

  Next, FIG. 3 is a top view of the diffusion combustion burner 100 shown in FIG. 1 as viewed from above. As shown in FIGS. 1 and 3, the diffusion combustion burner 100 in this embodiment arranges 3 × 10 = 30 sets of micro fuel heads 1 and micro air heads 2. And as above-mentioned, the internal diameter of the micro fuel head 1 shall be 2 mm or less. This is because when the inner diameter is greater than 2 mm, so many will not line up and will not burn on the surface. That is, since the diffusion combustion burner having a large number of sets of the micro fuel head 1 and the micro air head 2 can be burned in an array, there is an advantage that uniform heating can be performed.

  FIG. 4 is an enlarged view showing a positional relationship between one set of micro fuel head 1 and micro air head 2 and the adjacent micro fuel head 1 and micro air head 2 in the top view shown in FIG. Further, FIG. 5 is a table showing experimental results according to the distance between the central axis of one set of micro fuel head 1 and micro air head 2 and the central axes of micro fuel head 1 and micro air head 2 adjacent thereto. It is.

  As shown in FIG. 4, let L be the distance between the central axes of a set of micro fuel heads 1 and micro air heads 2 and the central axes of the micro fuel heads 1 and micro air heads 2 adjacent thereto. In FIG. 5, eight types of cases where the distance L between the central axes is 5.0 mm, 7.5 mm, 10.0 mm, 12.5 mm, 15.0 mm, 17.5 mm, 20.0 mm, 22.5 mm 4 shows the result of a test on whether one set of micro fuel head 1 and micro air head 2 burns next to one another.

  And, as shown in FIG. 5, in the case of L = 5.0 mm, 7.5 mm, 10.0 mm, 12.5 mm, 15.0 mm and 17.5 mm, the set of fires is smoothly adjacent without any problem The micro fuel head 1 and the micro air head 2 were burned and finally all the head pairs were fired and could be burned on the surface. In addition, in the case of L = 20.0 mm, although the case which takes some time was also seen, finally all the sets of heads were ignited and were able to burn in a field. However, in the case of L = 22.5 mm, there was a pair of heads which did not burn next to the fire and did not get fired.

  According to this experimental result, it is considered that when L is larger than 20 mm, the fire may not burn in the next set of the micro fuel head 1 and the micro air head 2. And if there is a place that is not lit even at one place, there is a possibility that it will burn suddenly suddenly, so it is dangerous if the heads of all the sets are not lit. Therefore, it is desirable that the distance L between the central axis of one set of micro fuel head 1 and micro air head 2 and the central axis of micro fuel head 1 and micro air head 2 adjacent thereto be 20 mm or less .

  The lower limit of the distance L between the central axes of one set of micro fuel head 1 and micro air head 2 and the adjacent micro fuel head 1 and micro air head 2 is the inner diameter of the micro fuel head 1 or The possible values necessarily depend on the tube thickness, the tube thickness and the outer diameter of the micro air head 2. As L is smaller, more sets of heads can be arranged, but since too small ones are difficult to manufacture, appropriate lower limits according to the inner diameters and tube thicknesses of the micro fuel head 1 and the micro air head 2 The value is determined inevitably.

  That is, by setting the distance between the central axis of one set of micro fuel head 1 and micro air head 2 and the central axis of the set of micro fuel head 1 and micro air head 2 adjacent thereto, to 20 mm or less. If one set of micro fuel head 1 and micro air head 2 is fired, the next set of micro fuel head 1 and micro air head 2 burns smoothly, and all heads are set in a short time Since it can be burnt on the surface, it can be manufactured and can be uniformly heated safely.

  The material of the diffusion combustion burner 100 according to the first embodiment of the present invention is, for example, stainless steel, titanium, inconel or the like. In the first embodiment, the diffusion combustion burner 100 is manufactured by a 3D printer. . As a result, as shown in the external configuration diagram of FIG. 1, since there is no need for screwing, there is also an advantage of being able to be miniaturized as compared to a burner of the screwing type.

  As described above, according to the diffusion combustion burner 100 in the first embodiment of the present invention, the upper end of the micro fuel head 1 is protruded above the upper end of the micro air head 2, so that the flame is stabilized (ignition stability Not only can ensure the properties and combustion stability) but also prevent the burnout of the head as a part. Further, by setting the inner diameter of the micro fuel head 1 to 2 mm or less, a large number of sets of the micro fuel head 1 and the micro air head 2 can be arranged. can do.

  Furthermore, the distance L between a central axis of a set of micro fuel heads 1 and a micro air head 2 and a central axis of a set of micro fuel heads 1 and a micro air head 2 adjacent to it is 20 mm or less. Therefore, when one set of micro fuel head 1 and micro air head 2 is ignited, the next set of micro fuel head 1 and micro air head 2 burns smoothly, and all sets of heads are assembled in a short time. As it can be lit and burned on the surface, it can be manufactured and safely heated uniformly.

  In the present invention, within the scope of the invention, modifications of optional components of the embodiment or omission of optional components of the embodiment is possible.

DESCRIPTION OF SYMBOLS 1 micro fuel head 2 micro air head 3 upper surface 10 of housing 10 housing 11 fuel chamber 12 air chamber 13 isolation layer 21 fuel introduction pipe 22 air introduction pipe 100 diffusion combustion burner

Claims (2)

A diffusion combustion burner for burning a fuel gas containing hydrogen as a fuel, comprising:
The diffusive combustion burner comprises, inside its housing, a fuel chamber and an air chamber separated by a separating layer,
A fuel introduction pipe for supplying a fuel gas containing hydrogen from the outside is connected to the fuel chamber, and an air introduction pipe for supplying air required for combustion from the outside is connected to the air chamber Yes,
A micro fuel head for injecting a fuel gas containing hydrogen from the fuel chamber above the upper surface of the housing; and a micro air head for injecting the air from the air chamber above the surface of the housing;
The micro fuel head and the micro air head are columnar tubes whose central axes are the same, the inner diameter of the micro fuel head is 2 mm or less, and the inner diameter of the micro air head is the same as that of the micro fuel head The upper end of the micro air head is larger than the outer diameter, and the upper end of the micro air head projects flush with or above the upper surface of the housing, and the upper end of the micro fuel head projects higher than the upper end of the micro air head A plurality of combinations of the micro fuel head and the micro air head disposed in a positional relationship of A distance between a set of the micro fuel head and the central axis of the micro air head and an adjacent set of the micro fuel head and the central axis of the micro air head is 20 mm or less. The diffusion combustion burner according to claim 1.

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