JP2001141208A - Burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for preventing slag from adhering to a burner panel and growing even when the flow rate of auxiliary air is low. SOLUTION: In order to eject auxiliary air obliquely upward along the installation plane of a burner panel 5, a burner nozzle at the tip of an auxiliary air burner 4 is directed obliquely upward. Since a negative pressure region is not formed in a space defined by a horizontal plane passing through the auxiliary air burner 4 and the burner panel 5, combustion exhaust gas in a boiler does not flow to the vicinity of the burner panel 5. Consequently, slag is prevented from adhering to the surface of the burner panel 5 and growing over a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner device suitable for use in a power generation boiler, a chemical industrial furnace, and the like.

[0002]

2. Description of the Related Art Conventionally, power generation boilers, chemical industry boilers, and the like often have water cooling tubes on their side walls in order to protect the boiler walls from the effects of heat and to endure long-term operation. . In such a boiler, a part of a group of water cooling tubes constituting the boiler side wall is gently bent obliquely outward at a predetermined position to form a burner panel, and the burner device is installed on the boiler side wall via the burner panel. I am trying to do it. As described above, the burner panel is formed of the same water-cooled tube as the boiler side wall, and thus has the same heat resistance as the boiler side wall. However, since the burner panel is provided near the tip of the burner (burner nozzle), there is a disadvantage that the burner panel is most susceptible to the influence of the radiant heat of the burner flame and is more likely to be damaged than other portions of the boiler side wall.

[0003] In order to alleviate such inconveniences, a burner device having an auxiliary air burner on the outer peripheral portion of the burner device has been proposed. FIG. 6 shows the auxiliary air burner 0.
4A and 4B show a conventional burner device 01 provided with the front burner 4, wherein FIG. 4A shows a front view thereof, and FIG. 4B shows a side view thereof. In a normal boiler, a plurality of burner devices 01 connected in a vertical direction are often arranged on four furnace walls, but FIG. 1 shows only one burner device among the burner device groups (the present application). In this case, the term "burner device" refers to this burner device alone, unless otherwise specified.) The burner device 01 is provided with a starting oil burner 02 provided at the center, a pulverized coal burner 03 arranged so as to vertically sandwich the starting oil burner 02, and a pulverized coal burner 03 arranged so as to vertically sandwich the same. The burner device is composed of an auxiliary air burner 04 and has a vertically long rectangular front surface. As described above, the auxiliary air burners 04 are arranged at the outermost portions above and below the burner device 01. Each of the burners 02, 03, and 04 has a burner nozzle disposed substantially in the horizontal direction.
Various fuels, combustion air, and the like are supplied to 3 and 04 from a fuel supply means or an air supply means (not shown). In such a burner device, the starting oil burner 0
Numeral 2 is used only for igniting and starting the burner main body 01, and the pulverized coal burner 03 mainly maintains the boiler flame 06 during the steady operation of the boiler. The auxiliary air burner 04
Like the pulverized coal burner 03, it is operated at the time of steady operation.

FIG. 5 is a side view showing an upper portion of the burner device 01. As shown in the figure, the auxiliary air ejected from the auxiliary air burner 04 is supplied between the pulverized coal flame 06 formed by the pulverized coal burner 03 and the burner panel 05.
It is injected almost horizontally. Then, by continuously injecting the auxiliary air to the above position, the burner panel 05 is protected from the influence of radiant heat due to the flame 06 from the pulverized coal burner 03, and the burner panel 05 is prevented from being damaged. In addition,
The flow rate of the air ejected from the auxiliary air nozzle 04 depends on whether the pulverized coal mixture is ejected from the pulverized coal burner 03 or the pulverized coal flame is zero.
In order to prevent the state of No. 6 from being adversely affected, the value is set to a value very smaller than the flow rate of the pulverized coal mixture injected from the pulverized coal burner 03.

[0005]

As described above, in the conventional burner apparatus 01, each of the burners 02 to 04 is installed in the horizontal direction (the direction of the dashed line A in the figure), and from the burners. Will flow in a substantially horizontal direction. On the other hand, as shown in FIG. 5, the burner panel 05 is arranged obliquely with respect to each of the burners, so that the auxiliary air blown out from the auxiliary air burner 04 should travel in the horizontal plane (the auxiliary air burner 04). A space 010 between the burner panel 05 and a substantially horizontal plane passing through the burner panel 05 (a plane substantially perpendicular to the plane of FIG. 5 through the broken line A).
Can be. This causes a negative pressure due to the flow of the auxiliary air from the auxiliary air nozzle 04, whereby a part of the combustion exhaust gas or the like in the boiler flows into this space 06 as shown by an arrow in FIG. Become. Then, the molten slag contained in the combustion exhaust gas flowing into the space 010 adheres to the surface of the burner panel 05 formed by the water-cooled tube, and is easily deposited and grown. At a relatively early stage of the boiler operation, the amount of the deposited and deposited molten slag is very small, so it does not matter much, but if the operation of the boiler is performed for a long time, the deposited and grown slag may form the auxiliary air burner 04 or the like. It is also conceivable to reach the nozzle portion of the pulverized coal burner 03, and in that case, the operation of the burner device 01 may be hindered. Further, when slag adheres and grows on the burner panel 05 below the burner device 01, the growth slag reaches another burner device 01 'which is provided under the burner device 01 and is connected therewith. ′ May be hindered.

Further, as described above, the flow rate of the auxiliary air ejected from the auxiliary air burner 04 is often controlled to some extent so as not to hinder the flow of the air-fuel mixture from the pulverized coal mixing burner 03. Is too small, the auxiliary air flow is drawn into the air-fuel mixture flow from the pulverized coal burner 03, and the area of the space 010 becomes large. Then, the flow rate of the combustion exhaust gas and the like flowing into the space 010 increases,
There is also an inconvenience of promoting adhesion and growth of slag on the burner panel 05. Therefore, an object of the present invention is to provide a means capable of suppressing the attachment and growth of slag to a burner panel for a long time even with a small amount of auxiliary air.

[0007]

In order to solve the above-mentioned problems, the present application provides the following means. (1) A burner device provided with an air burner as an uppermost burner, wherein an upper portion of the burner device is attached to the boiler via a burner panel provided at an angle to a side wall of the boiler. , Characterized in that air spouted from the air burner is jetted at least upward. (2) In the above (1), the burner nozzle at the tip of the air burner is disposed obliquely upward. (3) In the above (1), of the walls forming the restriction of the burner nozzle at the tip of the air burner, the lower wall is provided extending obliquely upward.

(4) In the above (1), a guide is provided in front of the air burner to divide air blown from the air burner in a vertical direction. (5) In the above (1), there is provided an opening formed above the burner nozzle at the tip of the air burner, and a guide vane provided to project from the opening to the inside of the air burner. . (6) In the above (1), a guide vane having at least a part of the downstream portion diverging is provided in the burner nozzle at the tip of the air burner. (7) A burner device provided with an air burner as a lowermost burner, wherein a lower portion of the burner device is attached to the boiler via a burner panel provided to be inclined with respect to a side wall of the boiler. The air blown from the air burner is jetted downward. (8) In the above (7), the burner nozzle at the tip of the air burner is arranged obliquely downward. (9) In the above (7), the upper wall of the wall forming the throttle of the burner nozzle at the tip of the air burner is provided extending obliquely downward. (10) In the above (7), a guide is provided in front of the air burner to divide air blown from the air burner in a vertical direction. (11) In the above (7), an opening formed at a lower portion of the burner nozzle at the tip of the air burner, and a guide vane provided to project from the opening into the air burner are provided. . (12) In the above (7), a guide vane having a downstream end diverging is provided in the burner nozzle at the tip of the air burner.

The above means have the following functions. In the means shown in (1) or (7), the air blown from the air burner is blown upward or downward toward the burner panel side, so that a negative pressure region is not formed in the space near the burner panel. Therefore, the flow of the combustion exhaust gas and the like in the boiler including the molten slag into the vicinity of the burner panel is reduced. In the means described in (2) or (8), the air from the air burner is injected obliquely upward or downward along the installation surface of the burner panel, and negative pressure is applied to the space near the burner panel. Region is not formed. Therefore, the flow of the combustion exhaust gas and the like in the boiler including the molten slag into the vicinity of the burner panel is reduced. In the means shown in (3) or (9),
The air blown from the burner nozzle at the tip of the air burner is blown obliquely upward or downward along the wall of the extended burner nozzle. Therefore, the injected air flows along the installation surface of the burner panel, and no negative pressure region is formed in the space near the burner panel. Therefore, the flow of the combustion exhaust gas and the like in the boiler including the molten slag into the vicinity of the burner panel is reduced.

In the means shown in (4), the air blown out from the air burner is divided by the guide in the vertical direction. Then, the upward flow is directed to the burner panel side, thereby preventing a negative pressure region from being formed in a space near the burner panel. On the other hand, the downward flow prevents a negative pressure area from being formed in the space below the air burner. Therefore,
The flow of the combustion exhaust gas and the like in the boiler containing the molten slag into the two spaces is reduced. In the means described in (5) or (11), a part of the air flowing in the air burner changes its direction along the guide vane and passes through an opening formed in the upper or lower part of the burner nozzle. Is injected upward or downward, that is, toward the burner panel side. Thereby, a negative pressure region is not formed in the space near the burner panel, and the flow of the combustion exhaust gas and the like in the boiler including the molten slag into the vicinity of the burner panel is reduced. (6) The air flowing in the air burner is divided vertically and vertically along the guide vanes. Then, the upward flow is directed to the burner panel side to prevent a negative pressure region from being formed in a space near the burner panel. On the other hand, the downward flow prevents a negative pressure area from being formed in the space below the air burner. Further, the straight flow prevents the formation of a negative pressure area in the space in front of the air burner. Therefore, the flow of the combustion exhaust gas and the like in the boiler including the molten slag into the three spaces is reduced. (10) The air blown out from the air burner is divided vertically by the guide. Then, the downward flow is directed to the burner panel side to prevent a negative pressure region from being formed in a space near the burner panel. On the other hand, the upward flow prevents a region of negative pressure from being formed in the space above the air burner. Therefore,
The flow of the combustion exhaust gas and the like in the boiler containing the molten slag into the two spaces is reduced. (12) The air flowing through the air burner is divided vertically and vertically along the guide vanes. Then, the downward flow is directed to the burner panel side to prevent a negative pressure region from being formed in a space near the burner panel. On the other hand, the upward flow prevents a region of negative pressure from being formed in the space above the air burner. Further, the straight flow prevents the formation of a negative pressure area in the space in front of the air burner. Therefore, the flow of the combustion exhaust gas and the like in the boiler including the molten slag into the three spaces is reduced.

[0011]

FIG. 1 is a side view showing an upper part of a burner device according to a first embodiment of the present invention. FIG. 2A shows a configuration in which the tip (burner nozzle) of the auxiliary air burner 4 is directed obliquely upward so that the auxiliary air is injected obliquely upward along the installation surface of the burner panel 5. . With such a configuration,
The space formed between the horizontal plane passing through the auxiliary air burner 4 (the plane passing through the broken line A in the drawing and perpendicular to the plane of the drawing) and the burner panel 5 no longer has a negative pressure area, and the combustion exhaust gas in the boiler Since the flow of the slag into the vicinity of the burner panel 5 becomes small, it is possible to prevent the slag from attaching and growing on the surface of the burner panel 5 for a long time. Note that the configuration shown in FIG. 1A is formed by bending the entire tip portion (burner nozzle) of the auxiliary air burner 4 obliquely upward. For example, as shown in FIG. Even if the lower wall of the wall forming the throttle of the burner nozzle at the tip of the air burner 4 is formed to be long obliquely upward, the same operation and effect as the configuration shown in the above (a) can be obtained.

FIG. 2 is a side view showing an upper part of a burner device according to a second embodiment of the present invention. In the figure, the auxiliary air burner 4 is formed substantially in the horizontal direction similarly to the conventional configuration, but is formed in front of the burner nozzle at the tip of the auxiliary air burner 4 so as to be divergent in the vertical direction. Guide 7 is provided.
The auxiliary air burner 4 is disposed such that a slight gap is formed between the nozzle opening at the tip of the auxiliary air burner 4 and the guide 7.
Along the vertical direction. As the guide 7, for example, as shown in FIG. 2, a member formed by bending an elongated plate along the longitudinal direction so as to have a “C” -shaped cross section is preferable. The auxiliary air blown from the auxiliary air burner 4 is divided into upper and lower portions at the corners of the guide 7, and the corners formed inside the boiler along the wall surface of the guide 7 To flow to.

By adopting the configuration of the present embodiment, the auxiliary air which is jetted from the auxiliary air burner 4 and which is jetted upward from the auxiliary air divided by the guide 7 is:
Since the air flows obliquely upward along the installation surface of the burner panel 5, a horizontal plane passing through the auxiliary air burner 4 (broken line A in the figure)
A negative pressure region is not formed in a space formed between the burner panel 5 and a plane perpendicular to the plane of FIG.
This eliminates the flow of the combustion exhaust gas and the like into the vicinity of the burner panel 5 in the boiler, so that the slag can be prevented from adhering and growing on the surface of the burner panel 5 for a long time.

On the other hand, of the auxiliary air divided by the guide 7, the auxiliary air injected downward flows obliquely downward toward the pulverized coal burner 3 side. The following actions and effects are achieved by forming the auxiliary air flow toward In the configuration in which the auxiliary air is jetted only obliquely upward from the auxiliary air burner 4 as in the first embodiment, the area between the auxiliary air burner 4 and the pulverized coal burner 3 has a negative pressure area. Is formed. When the combustion exhaust gas or the like in the boiler flows into the negative pressure region, it causes slag to adhere to the lower side wall of the auxiliary air burner 4. Then, as the slag grows, it may reach the nozzle of the pulverized coal burner 3, and in the worst case, the operation of the burner device 01 may be hindered. On the other hand, if an auxiliary air flow is formed obliquely below the auxiliary air burner 4,
Since no negative pressure area is formed below the auxiliary air burner 4, slag adheres to the lower side wall of the auxiliary air burner 4,
Growth can be prevented, and the reliability of the long-time operation of the boiler is further increased.

FIG. 3 is a side view showing an upper part of a burner device according to a third embodiment of the present invention. In the figure, the auxiliary air burner 4 has a burner nozzle formed substantially in the horizontal direction similarly to the conventional configuration, and additionally, an opening is provided at an upper portion of a wall forming a throttle toward the burner nozzle. The auxiliary air is injected obliquely upward through the opening. Further, the auxiliary air burner 4 is provided with a guide vane 8 which is provided so as to protrude from the above-mentioned opening toward an obliquely upstream side inward of the auxiliary air burner 4. A part of the auxiliary air flowing through the guide vanes 8 changes its direction along the guide vane 8 and is injected outside the auxiliary air burner 4 through the opening. As described above, in the present embodiment, the auxiliary air is divided and jetted obliquely upward and straight ahead. Therefore, a negative pressure area is not formed in a space formed between the horizontal plane passing through the auxiliary air burner 4 (a plane passing through the broken line A in the figure and perpendicular to the paper surface) and the burner panel 5, and the inside of the boiler Since the flow of the combustion exhaust gas and the like into the vicinity of the burner panel 5 at
Adhesion and growth of slag on the surface of the burner panel 5 can be prevented for a long time. Further, there is an effect that a negative pressure region is not formed in the space in front of the auxiliary air burner 4.

By appropriately determining the length of the guide vane 8, it is possible to adjust the flow rate of the auxiliary air ejected obliquely upward. However, a preferable length of the guide vane 8 is as follows. It is desirable that the length is long enough to reach the center of the flow path of the burner 4. If the guide vanes 8 do not reach the center of the flow path of the auxiliary air burner 4, most of the auxiliary air flowing in the auxiliary air burner 4 will proceed straight without shunting and will be ejected from the opening at the tip of the burner nozzle. This is because in some cases, it becomes difficult to secure a necessary amount of auxiliary air flow obliquely upward from the auxiliary air flow ejected from the opening at the tip of the burner nozzle. In the present embodiment, one or more openings may be provided in the upper part of the wall forming the throttle toward the burner nozzle of the auxiliary air burner 4. However, the viewpoint that a negative pressure region is not formed over the entire space formed between the horizontal plane passing through the auxiliary air burner 4 (the plane passing through the broken line A in the drawing and perpendicular to the paper surface) and the burner panel 5 is shown. Therefore, it can be said that it is preferable to provide a plurality.

FIG. 4 is a side view showing an upper part of a burner device according to a fourth embodiment of the present invention. In the figure, the auxiliary air burner 4 has a burner nozzle formed substantially in the horizontal direction similarly to the conventional configuration, but additionally, a guide vane 9 is provided inside the burner nozzle. The guide vane 9 has a shape in which at least a part of the downstream side is divergent in the vertical direction, and the auxiliary air flowing through the auxiliary air burner 4 is divided in the vertical and linear directions along the guide vane 9. It is arranged as follows. The opening of the burner nozzle of the auxiliary air burner 4 is also formed in a divergent shape along the divergent shape downstream of the guide vane 9.

By employing the configuration of the present embodiment, the auxiliary air flowing through the auxiliary air burner 4 is divided vertically and linearly along the guide vanes 9, and the opening of the burner nozzle in the auxiliary air burner 4. Auxiliary air can be injected obliquely up and down in the boiler without disturbing the flow along the shape of the boiler. Therefore, a negative pressure area is not formed in a space formed between the horizontal plane passing through the auxiliary air burner 4 (a plane passing through the broken line A in the figure and perpendicular to the paper surface) and the burner panel 5, and the inside of the boiler Since the flow of the combustion exhaust gas and the like into the vicinity of the burner panel 5 at the time of is reduced, it is possible to prevent the slag from attaching and growing on the surface of the burner panel 5 for a long time. Further, since a negative pressure region can be prevented from being formed below the auxiliary air burner 4, slag can be prevented from adhering to and growing on the lower side wall of the auxiliary air burner 4, and the reliability of the long-time operation of the boiler is further increased. It will be.

Further, in the present embodiment, since the downstream portion of the guide vane 9 is formed to be divergent, the auxiliary air that has passed through the auxiliary air burner 4 passes through the guide vane 9. Auxiliary air traveling straight diffuses slowly along the inner wall of the divergent portion without disturbing the flow. Therefore, a negative pressure region is not formed in the space in front of the auxiliary air burner 4 and the flow in the space is not disturbed. Therefore, it is possible to prevent an unnecessary gas flow from being formed in the space in front of the air burner, thereby improving the combustion efficiency of the entire boiler. In the above description, an example has been described in which the burner nozzle tip opening of the auxiliary air burner 4 is shaped along the guide vane 9. However, even when the burner nozzle tip is not formed in this way, the auxiliary air is supplied to the guide vane 9. Injected along the downstream divergent shape. Therefore, the shape of the burner nozzle tip is not always necessary. However, in order to maintain a uniform flow of the auxiliary air injected obliquely upward and downward without being disturbed, it is desirable that the tip of the burner nozzle has a shape.

As described above, an example in which the present invention is applied to the upper part of the burner device 1 has been described.
It is not limited to only the upper part of the burner device 1. For example, as shown in FIG. 6, a burner panel 5 is usually provided also at the lower part of the burner apparatus 1. Since the slag is likely to adhere and grow on this burner panel 5, the present invention is applied to the burner apparatus. May be applied to the lower part of the frame. Specifically, the auxiliary air burner 4 provided at the lowermost part of the burner device 1 is configured to have the structure shown in FIGS. 1 to 4 so that auxiliary air is injected obliquely downward along the installation surface of the burner panel 5. This can be realized by reversing the structure. In this case, the adhesion and growth of slag on the burner panel 5 and the like below the burner device 1 can be prevented for a long period of time, so that another burner device 1 ′ provided continuously below the burner device 1 is provided.
Thus, it is possible to prevent a situation in which the slag reaches to hinder the operation of the burner device 1 'for a long time.

[0021]

According to the first, second, third and fifth aspects of the present invention, it is possible to prevent the combustion exhaust gas and the like in the boiler from flowing into the space near the burner panel, and the slag is formed on the surface of the burner panel. Can be prevented from adhering and growing for a long time. Further, according to the invention described in claim 4 of the present application, in addition to the above effects, it is possible to prevent combustion exhaust gas and the like in the boiler from flowing into the space below the air burner, and to prevent slag from adhering to and growing on the lower side wall of the air burner. Therefore, the reliability of the long-time operation of the boiler is further increased. According to the invention described in claim 6 of the present application, in addition to the effects of the inventions of claims 1 to 5, in addition to the effects of the combustion exhaust gas in the boiler flowing into the space in front of the air burner, an unnecessary gas flow is formed. Thus, there is an effect that the combustion efficiency of the entire boiler is improved.

According to the invention described in claims 7, 8, 9 and 11 of the present application, slag adheres to the surface of the burner panel by preventing combustion exhaust gas and the like in the boiler from flowing into the space near the burner panel. Growth can be prevented over a long period of time, and slugs reach another burner device provided below the burner device, which can hinder the operation of the burner device for a long time. It is also possible to prevent it across. Further, according to the invention described in claim 10 of the present application, in addition to the effects of the inventions of claims 7, 8, 9 and 11, it is possible to prevent combustion exhaust gas and the like in the boiler from flowing into the space above the air burner, Since it is possible to prevent slag from adhering to and growing on the lower side wall of the air burner, there is an effect that reliability is further added for long-time operation of the boiler. According to the invention described in claim 12 of the present application, in addition to the effects of the inventions of claims 7 to 11,
This prevents the combustion exhaust gas or the like in the boiler from flowing into the space in front of the air burner, thereby preventing an unnecessary gas flow from being formed, thereby improving the combustion efficiency of the entire boiler.

[Brief description of the drawings]

FIG. 1 is a side view showing an upper part of a burner device according to a first embodiment of the present invention.

FIG. 2 is a side view showing an upper portion of a burner device according to a second embodiment of the present invention.

FIG. 3 is a side view showing an upper part of a burner device according to a third embodiment of the present invention.

FIG. 4 is a side view showing an upper part of a burner device according to a fourth embodiment of the present invention.

FIG. 5 is a side view showing an upper portion of a conventional burner device.

FIG. 6 is an external view showing a conventional burner device.

[Explanation of symbols]

 01, 1 burner device 02, 2 Starting oil burner 03, 3 Pulverized coal burner 04, 4 Auxiliary air burner 05, 5 Burner panel 06, 6 Flame 010 Negative pressure space 7 Guide 8 Guide vane 9 Guide vane

Claims (12)

[Claims] 1. A burner device provided with an air burner as an uppermost burner, wherein an upper portion of the burner device is attached to the boiler via a burner panel provided at an angle to a side wall of the boiler. A burner device wherein air blown from the air burner is injected upward. 2. The burner device according to claim 1, wherein the burner nozzle at the tip of the air burner is disposed obliquely upward. 3. The burner device according to claim 1, wherein a lower wall of the walls forming the throttle of the burner nozzle at the tip of the air burner is provided extending obliquely upward. 4. The burner device according to claim 1, further comprising a guide provided in front of the air burner to divide air blown from the air burner in a vertical direction. 5. The burner according to claim 1, further comprising an opening formed at an upper portion of the burner nozzle at a tip of the air burner, and a guide vane provided to project from the opening into the air burner. apparatus. 6. The burner device according to claim 1, wherein a guide vane having a downstream end diverging is provided in the burner nozzle at the tip of the air burner. 7. A burner device provided with an air burner as a lowermost burner, wherein a lower portion of the burner device is attached to the boiler via a burner panel provided at an angle to a side wall of the boiler. The air burner wherein the air blown from the air burner is blown downward. 8. The burner device according to claim 7, wherein the burner nozzle at the tip of the air burner is disposed obliquely downward. 9. The burner device according to claim 7, wherein, of the walls forming the throttle of the burner nozzle at the tip of the air burner, an upper wall is provided to extend obliquely downward. 10. The burner device according to claim 7, wherein a guide is provided in front of the air burner to divide air blown from the air burner in a vertical direction. 11. The burner according to claim 7, further comprising: an opening formed at a lower portion of the burner nozzle at the tip of the air burner; and a guide vane provided to project from the opening into the air burner. apparatus. 12. The burner device according to claim 8, wherein a guide vane having a downstream end diverging is provided in the burner nozzle at the tip of the air burner.